diff options
| author |   Mike Pagano <mpagano@gentoo.org> | 2021-11-21 15:56:06 -0500 |
|---|---|---|
| committer | Mike Pagano <mpagano@gentoo.org> | 2021-11-21 15:56:06 -0500 |
| commit | 3164db0223bf8d829b763411f45449277097f8d8 (patch) | |
| tree | acb32eaaa01b4943091ec9b53e4e6245956ca47c | |
| parent | Linux patch 5.15.4 (diff) | |
| download | linux-patches-5.15-6.tar.gz linux-patches-5.15-6.tar.bz2 linux-patches-5.15-6.zip | |
Remove old BMQ Patch5.15-6
Signed-off-by: Mike Pagano <mpagano@gentoo.org>
| -rw-r--r-- | 5020_BMQ-and-PDS-io-scheduler-v5.15-r0.patch | 9798 |
1 files changed, 0 insertions, 9798 deletions
diff --git a/5020_BMQ-and-PDS-io-scheduler-v5.15-r0.patch b/5020_BMQ-and-PDS-io-scheduler-v5.15-r0.patch deleted file mode 100644 index c22cf656..00000000 --- a/5020_BMQ-and-PDS-io-scheduler-v5.15-r0.patch +++ /dev/null @@ -1,9798 +0,0 @@ -diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt -index 43dc35fe5bc0..0873e92ca5d0 100644 ---- a/Documentation/admin-guide/kernel-parameters.txt -+++ b/Documentation/admin-guide/kernel-parameters.txt -@@ -4985,6 +4985,12 @@ - sa1100ir [NET] - See drivers/net/irda/sa1100_ir.c. - -+ sched_timeslice= -+ [KNL] Time slice in ms for Project C BMQ/PDS scheduler. -+ Format: integer 2, 4 -+ Default: 4 -+ See Documentation/scheduler/sched-BMQ.txt -+ - sched_verbose [KNL] Enables verbose scheduler debug messages. - - schedstats= [KNL,X86] Enable or disable scheduled statistics. -diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst -index 426162009ce9..15ac2d7e47cd 100644 ---- a/Documentation/admin-guide/sysctl/kernel.rst -+++ b/Documentation/admin-guide/sysctl/kernel.rst -@@ -1542,3 +1542,13 @@ is 10 seconds. - - The softlockup threshold is (``2 * watchdog_thresh``). Setting this - tunable to zero will disable lockup detection altogether. -+ -+yield_type: -+=========== -+ -+BMQ/PDS CPU scheduler only. This determines what type of yield calls -+to sched_yield will perform. -+ -+ 0 - No yield. -+ 1 - Deboost and requeue task. (default) -+ 2 - Set run queue skip task. -diff --git a/Documentation/scheduler/sched-BMQ.txt b/Documentation/scheduler/sched-BMQ.txt -new file mode 100644 -index 000000000000..05c84eec0f31 ---- /dev/null -+++ b/Documentation/scheduler/sched-BMQ.txt -@@ -0,0 +1,110 @@ -+ BitMap queue CPU Scheduler -+ -------------------------- -+ -+CONTENT -+======== -+ -+ Background -+ Design -+ Overview -+ Task policy -+ Priority management -+ BitMap Queue -+ CPU Assignment and Migration -+ -+ -+Background -+========== -+ -+BitMap Queue CPU scheduler, referred to as BMQ from here on, is an evolution -+of previous Priority and Deadline based Skiplist multiple queue scheduler(PDS), -+and inspired by Zircon scheduler. The goal of it is to keep the scheduler code -+simple, while efficiency and scalable for interactive tasks, such as desktop, -+movie playback and gaming etc. -+ -+Design -+====== -+ -+Overview -+-------- -+ -+BMQ use per CPU run queue design, each CPU(logical) has it's own run queue, -+each CPU is responsible for scheduling the tasks that are putting into it's -+run queue. -+ -+The run queue is a set of priority queues. Note that these queues are fifo -+queue for non-rt tasks or priority queue for rt tasks in data structure. See -+BitMap Queue below for details. BMQ is optimized for non-rt tasks in the fact -+that most applications are non-rt tasks. No matter the queue is fifo or -+priority, In each queue is an ordered list of runnable tasks awaiting execution -+and the data structures are the same. When it is time for a new task to run, -+the scheduler simply looks the lowest numbered queueue that contains a task, -+and runs the first task from the head of that queue. And per CPU idle task is -+also in the run queue, so the scheduler can always find a task to run on from -+its run queue. -+ -+Each task will assigned the same timeslice(default 4ms) when it is picked to -+start running. Task will be reinserted at the end of the appropriate priority -+queue when it uses its whole timeslice. When the scheduler selects a new task -+from the priority queue it sets the CPU's preemption timer for the remainder of -+the previous timeslice. When that timer fires the scheduler will stop execution -+on that task, select another task and start over again. -+ -+If a task blocks waiting for a shared resource then it's taken out of its -+priority queue and is placed in a wait queue for the shared resource. When it -+is unblocked it will be reinserted in the appropriate priority queue of an -+eligible CPU. -+ -+Task policy -+----------- -+ -+BMQ supports DEADLINE, FIFO, RR, NORMAL, BATCH and IDLE task policy like the -+mainline CFS scheduler. But BMQ is heavy optimized for non-rt task, that's -+NORMAL/BATCH/IDLE policy tasks. Below is the implementation detail of each -+policy. -+ -+DEADLINE -+ It is squashed as priority 0 FIFO task. -+ -+FIFO/RR -+ All RT tasks share one single priority queue in BMQ run queue designed. The -+complexity of insert operation is O(n). BMQ is not designed for system runs -+with major rt policy tasks. -+ -+NORMAL/BATCH/IDLE -+ BATCH and IDLE tasks are treated as the same policy. They compete CPU with -+NORMAL policy tasks, but they just don't boost. To control the priority of -+NORMAL/BATCH/IDLE tasks, simply use nice level. -+ -+ISO -+ ISO policy is not supported in BMQ. Please use nice level -20 NORMAL policy -+task instead. -+ -+Priority management -+------------------- -+ -+RT tasks have priority from 0-99. For non-rt tasks, there are three different -+factors used to determine the effective priority of a task. The effective -+priority being what is used to determine which queue it will be in. -+ -+The first factor is simply the task’s static priority. Which is assigned from -+task's nice level, within [-20, 19] in userland's point of view and [0, 39] -+internally. -+ -+The second factor is the priority boost. This is a value bounded between -+[-MAX_PRIORITY_ADJ, MAX_PRIORITY_ADJ] used to offset the base priority, it is -+modified by the following cases: -+ -+*When a thread has used up its entire timeslice, always deboost its boost by -+increasing by one. -+*When a thread gives up cpu control(voluntary or non-voluntary) to reschedule, -+and its switch-in time(time after last switch and run) below the thredhold -+based on its priority boost, will boost its boost by decreasing by one buti is -+capped at 0 (won’t go negative). -+ -+The intent in this system is to ensure that interactive threads are serviced -+quickly. These are usually the threads that interact directly with the user -+and cause user-perceivable latency. These threads usually do little work and -+spend most of their time blocked awaiting another user event. So they get the -+priority boost from unblocking while background threads that do most of the -+processing receive the priority penalty for using their entire timeslice. -diff --git a/fs/proc/base.c b/fs/proc/base.c -index 533d5836eb9a..5756c51c9b58 100644 ---- a/fs/proc/base.c -+++ b/fs/proc/base.c -@@ -477,7 +477,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, - seq_puts(m, "0 0 0\n"); - else - seq_printf(m, "%llu %llu %lu\n", -- (unsigned long long)task->se.sum_exec_runtime, -+ (unsigned long long)tsk_seruntime(task), - (unsigned long long)task->sched_info.run_delay, - task->sched_info.pcount); - -diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h -index 8874f681b056..59eb72bf7d5f 100644 ---- a/include/asm-generic/resource.h -+++ b/include/asm-generic/resource.h -@@ -23,7 +23,7 @@ - [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \ - [RLIMIT_SIGPENDING] = { 0, 0 }, \ - [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \ -- [RLIMIT_NICE] = { 0, 0 }, \ -+ [RLIMIT_NICE] = { 30, 30 }, \ - [RLIMIT_RTPRIO] = { 0, 0 }, \ - [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \ - } -diff --git a/include/linux/sched.h b/include/linux/sched.h -index c1a927ddec64..a7eb91d15442 100644 ---- a/include/linux/sched.h -+++ b/include/linux/sched.h -@@ -748,12 +748,18 @@ struct task_struct { - unsigned int ptrace; - - #ifdef CONFIG_SMP -- int on_cpu; - struct __call_single_node wake_entry; -+#endif -+#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_ALT) -+ int on_cpu; -+#endif -+ -+#ifdef CONFIG_SMP - #ifdef CONFIG_THREAD_INFO_IN_TASK - /* Current CPU: */ - unsigned int cpu; - #endif -+#ifndef CONFIG_SCHED_ALT - unsigned int wakee_flips; - unsigned long wakee_flip_decay_ts; - struct task_struct *last_wakee; -@@ -767,6 +773,7 @@ struct task_struct { - */ - int recent_used_cpu; - int wake_cpu; -+#endif /* !CONFIG_SCHED_ALT */ - #endif - int on_rq; - -@@ -775,6 +782,20 @@ struct task_struct { - int normal_prio; - unsigned int rt_priority; - -+#ifdef CONFIG_SCHED_ALT -+ u64 last_ran; -+ s64 time_slice; -+ int sq_idx; -+ struct list_head sq_node; -+#ifdef CONFIG_SCHED_BMQ -+ int boost_prio; -+#endif /* CONFIG_SCHED_BMQ */ -+#ifdef CONFIG_SCHED_PDS -+ u64 deadline; -+#endif /* CONFIG_SCHED_PDS */ -+ /* sched_clock time spent running */ -+ u64 sched_time; -+#else /* !CONFIG_SCHED_ALT */ - const struct sched_class *sched_class; - struct sched_entity se; - struct sched_rt_entity rt; -@@ -785,6 +806,7 @@ struct task_struct { - unsigned long core_cookie; - unsigned int core_occupation; - #endif -+#endif /* !CONFIG_SCHED_ALT */ - - #ifdef CONFIG_CGROUP_SCHED - struct task_group *sched_task_group; -@@ -1505,6 +1527,15 @@ struct task_struct { - */ - }; - -+#ifdef CONFIG_SCHED_ALT -+#define tsk_seruntime(t) ((t)->sched_time) -+/* replace the uncertian rt_timeout with 0UL */ -+#define tsk_rttimeout(t) (0UL) -+#else /* CFS */ -+#define tsk_seruntime(t) ((t)->se.sum_exec_runtime) -+#define tsk_rttimeout(t) ((t)->rt.timeout) -+#endif /* !CONFIG_SCHED_ALT */ -+ - static inline struct pid *task_pid(struct task_struct *task) - { - return task->thread_pid; -diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h -index 1aff00b65f3c..216fdf2fe90c 100644 ---- a/include/linux/sched/deadline.h -+++ b/include/linux/sched/deadline.h -@@ -1,5 +1,24 @@ - /* SPDX-License-Identifier: GPL-2.0 */ - -+#ifdef CONFIG_SCHED_ALT -+ -+static inline int dl_task(struct task_struct *p) -+{ -+ return 0; -+} -+ -+#ifdef CONFIG_SCHED_BMQ -+#define __tsk_deadline(p) (0UL) -+#endif -+ -+#ifdef CONFIG_SCHED_PDS -+#define __tsk_deadline(p) ((((u64) ((p)->prio))<<56) | (p)->deadline) -+#endif -+ -+#else -+ -+#define __tsk_deadline(p) ((p)->dl.deadline) -+ - /* - * SCHED_DEADLINE tasks has negative priorities, reflecting - * the fact that any of them has higher prio than RT and -@@ -19,6 +38,7 @@ static inline int dl_task(struct task_struct *p) - { - return dl_prio(p->prio); - } -+#endif /* CONFIG_SCHED_ALT */ - - static inline bool dl_time_before(u64 a, u64 b) - { -diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h -index ab83d85e1183..6af9ae681116 100644 ---- a/include/linux/sched/prio.h -+++ b/include/linux/sched/prio.h -@@ -18,6 +18,32 @@ - #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) - #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) - -+#ifdef CONFIG_SCHED_ALT -+ -+/* Undefine MAX_PRIO and DEFAULT_PRIO */ -+#undef MAX_PRIO -+#undef DEFAULT_PRIO -+ -+/* +/- priority levels from the base priority */ -+#ifdef CONFIG_SCHED_BMQ -+#define MAX_PRIORITY_ADJ (7) -+ -+#define MIN_NORMAL_PRIO (MAX_RT_PRIO) -+#define MAX_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH) -+#define DEFAULT_PRIO (MIN_NORMAL_PRIO + NICE_WIDTH / 2) -+#endif -+ -+#ifdef CONFIG_SCHED_PDS -+#define MAX_PRIORITY_ADJ (0) -+ -+#define MIN_NORMAL_PRIO (128) -+#define NORMAL_PRIO_NUM (64) -+#define MAX_PRIO (MIN_NORMAL_PRIO + NORMAL_PRIO_NUM) -+#define DEFAULT_PRIO (MAX_PRIO - NICE_WIDTH / 2) -+#endif -+ -+#endif /* CONFIG_SCHED_ALT */ -+ - /* - * Convert user-nice values [ -20 ... 0 ... 19 ] - * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], -diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h -index e5af028c08b4..0a7565d0d3cf 100644 ---- a/include/linux/sched/rt.h -+++ b/include/linux/sched/rt.h -@@ -24,8 +24,10 @@ static inline bool task_is_realtime(struct task_struct *tsk) - - if (policy == SCHED_FIFO || policy == SCHED_RR) - return true; -+#ifndef CONFIG_SCHED_ALT - if (policy == SCHED_DEADLINE) - return true; -+#endif - return false; - } - -diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h -index 8f0f778b7c91..991f2280475b 100644 ---- a/include/linux/sched/topology.h -+++ b/include/linux/sched/topology.h -@@ -225,7 +225,8 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu) - - #endif /* !CONFIG_SMP */ - --#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) -+#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) && \ -+ !defined(CONFIG_SCHED_ALT) - extern void rebuild_sched_domains_energy(void); - #else - static inline void rebuild_sched_domains_energy(void) -diff --git a/init/Kconfig b/init/Kconfig -index 11f8a845f259..c8e82fcafb9e 100644 ---- a/init/Kconfig -+++ b/init/Kconfig -@@ -814,9 +814,39 @@ config GENERIC_SCHED_CLOCK - - menu "Scheduler features" - -+menuconfig SCHED_ALT -+ bool "Alternative CPU Schedulers" -+ default y -+ help -+ This feature enable alternative CPU scheduler" -+ -+if SCHED_ALT -+ -+choice -+ prompt "Alternative CPU Scheduler" -+ default SCHED_BMQ -+ -+config SCHED_BMQ -+ bool "BMQ CPU scheduler" -+ help -+ The BitMap Queue CPU scheduler for excellent interactivity and -+ responsiveness on the desktop and solid scalability on normal -+ hardware and commodity servers. -+ -+config SCHED_PDS -+ bool "PDS CPU scheduler" -+ help -+ The Priority and Deadline based Skip list multiple queue CPU -+ Scheduler. -+ -+endchoice -+ -+endif -+ - config UCLAMP_TASK - bool "Enable utilization clamping for RT/FAIR tasks" - depends on CPU_FREQ_GOV_SCHEDUTIL -+ depends on !SCHED_ALT - help - This feature enables the scheduler to track the clamped utilization - of each CPU based on RUNNABLE tasks scheduled on that CPU. -@@ -902,6 +932,7 @@ config NUMA_BALANCING - depends on ARCH_SUPPORTS_NUMA_BALANCING - depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY - depends on SMP && NUMA && MIGRATION -+ depends on !SCHED_ALT - help - This option adds support for automatic NUMA aware memory/task placement. - The mechanism is quite primitive and is based on migrating memory when -@@ -994,6 +1025,7 @@ config FAIR_GROUP_SCHED - depends on CGROUP_SCHED - default CGROUP_SCHED - -+if !SCHED_ALT - config CFS_BANDWIDTH - bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" - depends on FAIR_GROUP_SCHED -@@ -1016,6 +1048,7 @@ config RT_GROUP_SCHED - realtime bandwidth for them. - See Documentation/scheduler/sched-rt-group.rst for more information. - -+endif #!SCHED_ALT - endif #CGROUP_SCHED - - config UCLAMP_TASK_GROUP -@@ -1259,6 +1292,7 @@ config CHECKPOINT_RESTORE - - config SCHED_AUTOGROUP - bool "Automatic process group scheduling" -+ depends on !SCHED_ALT - select CGROUPS - select CGROUP_SCHED - select FAIR_GROUP_SCHED -diff --git a/init/init_task.c b/init/init_task.c -index 2d024066e27b..49f706df0904 100644 ---- a/init/init_task.c -+++ b/init/init_task.c -@@ -75,9 +75,15 @@ struct task_struct init_task - .stack = init_stack, - .usage = REFCOUNT_INIT(2), - .flags = PF_KTHREAD, -+#ifdef CONFIG_SCHED_ALT -+ .prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, -+ .static_prio = DEFAULT_PRIO, -+ .normal_prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, -+#else - .prio = MAX_PRIO - 20, - .static_prio = MAX_PRIO - 20, - .normal_prio = MAX_PRIO - 20, -+#endif - .policy = SCHED_NORMAL, - .cpus_ptr = &init_task.cpus_mask, - .user_cpus_ptr = NULL, -@@ -88,6 +94,17 @@ struct task_struct init_task - .restart_block = { - .fn = do_no_restart_syscall, - }, -+#ifdef CONFIG_SCHED_ALT -+ .sq_node = LIST_HEAD_INIT(init_task.sq_node), -+#ifdef CONFIG_SCHED_BMQ -+ .boost_prio = 0, -+ .sq_idx = 15, -+#endif -+#ifdef CONFIG_SCHED_PDS -+ .deadline = 0, -+#endif -+ .time_slice = HZ, -+#else - .se = { - .group_node = LIST_HEAD_INIT(init_task.se.group_node), - }, -@@ -95,6 +112,7 @@ struct task_struct init_task - .run_list = LIST_HEAD_INIT(init_task.rt.run_list), - .time_slice = RR_TIMESLICE, - }, -+#endif - .tasks = LIST_HEAD_INIT(init_task.tasks), - #ifdef CONFIG_SMP - .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO), -diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt -index 5876e30c5740..7594d0a31869 100644 ---- a/kernel/Kconfig.preempt -+++ b/kernel/Kconfig.preempt -@@ -102,7 +102,7 @@ config PREEMPT_DYNAMIC - - config SCHED_CORE - bool "Core Scheduling for SMT" -- depends on SCHED_SMT -+ depends on SCHED_SMT && !SCHED_ALT - help - This option permits Core Scheduling, a means of coordinated task - selection across SMT siblings. When enabled -- see -diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c -index 2a9695ccb65f..292112c267b8 100644 ---- a/kernel/cgroup/cpuset.c -+++ b/kernel/cgroup/cpuset.c -@@ -664,7 +664,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) - return ret; - } - --#ifdef CONFIG_SMP -+#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_ALT) - /* - * Helper routine for generate_sched_domains(). - * Do cpusets a, b have overlapping effective cpus_allowed masks? -@@ -1060,7 +1060,7 @@ static void rebuild_sched_domains_locked(void) - /* Have scheduler rebuild the domains */ - partition_and_rebuild_sched_domains(ndoms, doms, attr); - } --#else /* !CONFIG_SMP */ -+#else /* !CONFIG_SMP || CONFIG_SCHED_ALT */ - static void rebuild_sched_domains_locked(void) - { - } -diff --git a/kernel/delayacct.c b/kernel/delayacct.c -index 51530d5b15a8..e542d71bb94b 100644 ---- a/kernel/delayacct.c -+++ b/kernel/delayacct.c -@@ -139,7 +139,7 @@ int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) - */ - t1 = tsk->sched_info.pcount; - t2 = tsk->sched_info.run_delay; -- t3 = tsk->se.sum_exec_runtime; -+ t3 = tsk_seruntime(tsk); - - d->cpu_count += t1; - -diff --git a/kernel/exit.c b/kernel/exit.c -index 91a43e57a32e..4b157befc10c 100644 ---- a/kernel/exit.c -+++ b/kernel/exit.c -@@ -122,7 +122,7 @@ static void __exit_signal(struct task_struct *tsk) - sig->curr_target = next_thread(tsk); - } - -- add_device_randomness((const void*) &tsk->se.sum_exec_runtime, -+ add_device_randomness((const void*) &tsk_seruntime(tsk), - sizeof(unsigned long long)); - - /* -@@ -143,7 +143,7 @@ static void __exit_signal(struct task_struct *tsk) - sig->inblock += task_io_get_inblock(tsk); - sig->oublock += task_io_get_oublock(tsk); - task_io_accounting_add(&sig->ioac, &tsk->ioac); -- sig->sum_sched_runtime += tsk->se.sum_exec_runtime; -+ sig->sum_sched_runtime += tsk_seruntime(tsk); - sig->nr_threads--; - __unhash_process(tsk, group_dead); - write_sequnlock(&sig->stats_lock); -diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c -index 291b857a6e20..f3480cdb7497 100644 ---- a/kernel/livepatch/transition.c -+++ b/kernel/livepatch/transition.c -@@ -307,7 +307,11 @@ static bool klp_try_switch_task(struct task_struct *task) - */ - rq = task_rq_lock(task, &flags); - -+#ifdef CONFIG_SCHED_ALT -+ if (task_running(task) && task != current) { -+#else - if (task_running(rq, task) && task != current) { -+#endif - snprintf(err_buf, STACK_ERR_BUF_SIZE, - "%s: %s:%d is running\n", __func__, task->comm, - task->pid); -diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c -index 6bb116c559b4..d4c8168a8270 100644 ---- a/kernel/locking/rtmutex.c -+++ b/kernel/locking/rtmutex.c -@@ -298,21 +298,25 @@ static __always_inline void - waiter_update_prio(struct rt_mutex_waiter *waiter, struct task_struct *task) - { - waiter->prio = __waiter_prio(task); -- waiter->deadline = task->dl.deadline; -+ waiter->deadline = __tsk_deadline(task); - } - - /* - * Only use with rt_mutex_waiter_{less,equal}() - */ - #define task_to_waiter(p) \ -- &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = (p)->dl.deadline } -+ &(struct rt_mutex_waiter){ .prio = __waiter_prio(p), .deadline = __tsk_deadline(p) } - - static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, - struct rt_mutex_waiter *right) - { -+#ifdef CONFIG_SCHED_PDS -+ return (left->deadline < right->deadline); -+#else - if (left->prio < right->prio) - return 1; - -+#ifndef CONFIG_SCHED_BMQ - /* - * If both waiters have dl_prio(), we check the deadlines of the - * associated tasks. -@@ -321,16 +325,22 @@ static __always_inline int rt_mutex_waiter_less(struct rt_mutex_waiter *left, - */ - if (dl_prio(left->prio)) - return dl_time_before(left->deadline, right->deadline); -+#endif - - return 0; -+#endif - } - - static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, - struct rt_mutex_waiter *right) - { -+#ifdef CONFIG_SCHED_PDS -+ return (left->deadline == right->deadline); -+#else - if (left->prio != right->prio) - return 0; - -+#ifndef CONFIG_SCHED_BMQ - /* - * If both waiters have dl_prio(), we check the deadlines of the - * associated tasks. -@@ -339,8 +349,10 @@ static __always_inline int rt_mutex_waiter_equal(struct rt_mutex_waiter *left, - */ - if (dl_prio(left->prio)) - return left->deadline == right->deadline; -+#endif - - return 1; -+#endif - } - - static inline bool rt_mutex_steal(struct rt_mutex_waiter *waiter, -diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile -index 978fcfca5871..0425ee149b4d 100644 ---- a/kernel/sched/Makefile -+++ b/kernel/sched/Makefile -@@ -22,14 +22,21 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) - CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer - endif - --obj-y += core.o loadavg.o clock.o cputime.o --obj-y += idle.o fair.o rt.o deadline.o --obj-y += wait.o wait_bit.o swait.o completion.o -- --obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o -+ifdef CONFIG_SCHED_ALT -+obj-y += alt_core.o -+obj-$(CONFIG_SCHED_DEBUG) += alt_debug.o -+else -+obj-y += core.o -+obj-y += fair.o rt.o deadline.o -+obj-$(CONFIG_SMP) += cpudeadline.o stop_task.o - obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o --obj-$(CONFIG_SCHEDSTATS) += stats.o -+endif - obj-$(CONFIG_SCHED_DEBUG) += debug.o -+obj-y += loadavg.o clock.o cputime.o -+obj-y += idle.o -+obj-y += wait.o wait_bit.o swait.o completion.o -+obj-$(CONFIG_SMP) += cpupri.o pelt.o topology.o -+obj-$(CONFIG_SCHEDSTATS) += stats.o - obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o - obj-$(CONFIG_CPU_FREQ) += cpufreq.o - obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o -diff --git a/kernel/sched/alt_core.c b/kernel/sched/alt_core.c -new file mode 100644 -index 000000000000..9576c57f82da ---- /dev/null -+++ b/kernel/sched/alt_core.c -@@ -0,0 +1,7626 @@ -+/* -+ * kernel/sched/alt_core.c -+ * -+ * Core alternative kernel scheduler code and related syscalls -+ * -+ * Copyright (C) 1991-2002 Linus Torvalds -+ * -+ * 2009-08-13 Brainfuck deadline scheduling policy by Con Kolivas deletes -+ * a whole lot of those previous things. -+ * 2017-09-06 Priority and Deadline based Skip list multiple queue kernel -+ * scheduler by Alfred Chen. -+ * 2019-02-20 BMQ(BitMap Queue) kernel scheduler by Alfred Chen. -+ */ -+#define CREATE_TRACE_POINTS -+#include <trace/events/sched.h> -+#undef CREATE_TRACE_POINTS -+ -+#include "sched.h" -+ -+#include <linux/sched/rt.h> -+ -+#include <linux/context_tracking.h> -+#include <linux/compat.h> -+#include <linux/blkdev.h> -+#include <linux/delayacct.h> -+#include <linux/freezer.h> -+#include <linux/init_task.h> -+#include <linux/kprobes.h> -+#include <linux/mmu_context.h> -+#include <linux/nmi.h> -+#include <linux/profile.h> -+#include <linux/rcupdate_wait.h> -+#include <linux/security.h> -+#include <linux/syscalls.h> -+#include <linux/wait_bit.h> -+ -+#include <linux/kcov.h> -+#include <linux/scs.h> -+ -+#include <asm/switch_to.h> -+ -+#include "../workqueue_internal.h" -+#include "../../fs/io-wq.h" -+#include "../smpboot.h" -+ -+#include "pelt.h" -+#include "smp.h" -+ -+/* -+ * Export tracepoints that act as a bare tracehook (ie: have no trace event -+ * associated with them) to allow external modules to probe them. -+ */ -+EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp); -+ -+#ifdef CONFIG_SCHED_DEBUG -+#define sched_feat(x) (1) -+/* -+ * Print a warning if need_resched is set for the given duration (if -+ * LATENCY_WARN is enabled). -+ * -+ * If sysctl_resched_latency_warn_once is set, only one warning will be shown -+ * per boot. -+ */ -+__read_mostly int sysctl_resched_latency_warn_ms = 100; -+__read_mostly int sysctl_resched_latency_warn_once = 1; -+#else -+#define sched_feat(x) (0) -+#endif /* CONFIG_SCHED_DEBUG */ -+ -+#define ALT_SCHED_VERSION "v5.15-r0" -+ -+/* rt_prio(prio) defined in include/linux/sched/rt.h */ -+#define rt_task(p) rt_prio((p)->prio) -+#define rt_policy(policy) ((policy) == SCHED_FIFO || (policy) == SCHED_RR) -+#define task_has_rt_policy(p) (rt_policy((p)->policy)) -+ -+#define STOP_PRIO (MAX_RT_PRIO - 1) -+ -+/* Default time slice is 4 in ms, can be set via kernel parameter "sched_timeslice" */ -+u64 sched_timeslice_ns __read_mostly = (4 << 20); -+ -+static inline void requeue_task(struct task_struct *p, struct rq *rq); -+ -+#ifdef CONFIG_SCHED_BMQ -+#include "bmq.h" -+#endif -+#ifdef CONFIG_SCHED_PDS -+#include "pds.h" -+#endif -+ -+static int __init sched_timeslice(char *str) -+{ -+ int timeslice_ms; -+ -+ get_option(&str, ×lice_ms); -+ if (2 != timeslice_ms) -+ timeslice_ms = 4; -+ sched_timeslice_ns = timeslice_ms << 20; -+ sched_timeslice_imp(timeslice_ms); -+ -+ return 0; -+} -+early_param("sched_timeslice", sched_timeslice); -+ -+/* Reschedule if less than this many μs left */ -+#define RESCHED_NS (100 << 10) -+ -+/** -+ * sched_yield_type - Choose what sort of yield sched_yield will perform. -+ * 0: No yield. -+ * 1: Deboost and requeue task. (default) -+ * 2: Set rq skip task. -+ */ -+int sched_yield_type __read_mostly = 1; -+ -+#ifdef CONFIG_SMP -+static cpumask_t sched_rq_pending_mask ____cacheline_aligned_in_smp; -+ -+DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); -+DEFINE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); -+DEFINE_PER_CPU(cpumask_t *, sched_cpu_topo_end_mask); -+ -+#ifdef CONFIG_SCHED_SMT -+DEFINE_STATIC_KEY_FALSE(sched_smt_present); -+EXPORT_SYMBOL_GPL(sched_smt_present); -+#endif -+ -+/* -+ * Keep a unique ID per domain (we use the first CPUs number in the cpumask of -+ * the domain), this allows us to quickly tell if two cpus are in the same cache -+ * domain, see cpus_share_cache(). -+ */ -+DEFINE_PER_CPU(int, sd_llc_id); -+#endif /* CONFIG_SMP */ -+ -+static DEFINE_MUTEX(sched_hotcpu_mutex); -+ -+DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -+ -+#ifndef prepare_arch_switch -+# define prepare_arch_switch(next) do { } while (0) -+#endif -+#ifndef finish_arch_post_lock_switch -+# define finish_arch_post_lock_switch() do { } while (0) -+#endif -+ -+#ifdef CONFIG_SCHED_SMT -+static cpumask_t sched_sg_idle_mask ____cacheline_aligned_in_smp; -+#endif -+static cpumask_t sched_rq_watermark[SCHED_BITS] ____cacheline_aligned_in_smp; -+ -+/* sched_queue related functions */ -+static inline void sched_queue_init(struct sched_queue *q) -+{ -+ int i; -+ -+ bitmap_zero(q->bitmap, SCHED_BITS); -+ for(i = 0; i < SCHED_BITS; i++) -+ INIT_LIST_HEAD(&q->heads[i]); -+} -+ -+/* -+ * Init idle task and put into queue structure of rq -+ * IMPORTANT: may be called multiple times for a single cpu -+ */ -+static inline void sched_queue_init_idle(struct sched_queue *q, -+ struct task_struct *idle) -+{ -+ idle->sq_idx = IDLE_TASK_SCHED_PRIO; -+ INIT_LIST_HEAD(&q->heads[idle->sq_idx]); -+ list_add(&idle->sq_node, &q->heads[idle->sq_idx]); -+} -+ -+/* water mark related functions */ -+static inline void update_sched_rq_watermark(struct rq *rq) -+{ -+ unsigned long watermark = find_first_bit(rq->queue.bitmap, SCHED_QUEUE_BITS); -+ unsigned long last_wm = rq->watermark; -+ unsigned long i; -+ int cpu; -+ -+ if (watermark == last_wm) -+ return; -+ -+ rq->watermark = watermark; -+ cpu = cpu_of(rq); -+ if (watermark < last_wm) { -+ for (i = last_wm; i > watermark; i--) -+ cpumask_clear_cpu(cpu, sched_rq_watermark + SCHED_BITS - 1 - i); -+#ifdef CONFIG_SCHED_SMT -+ if (static_branch_likely(&sched_smt_present) && -+ IDLE_TASK_SCHED_PRIO == last_wm) -+ cpumask_andnot(&sched_sg_idle_mask, -+ &sched_sg_idle_mask, cpu_smt_mask(cpu)); -+#endif -+ return; -+ } -+ /* last_wm < watermark */ -+ for (i = watermark; i > last_wm; i--) -+ cpumask_set_cpu(cpu, sched_rq_watermark + SCHED_BITS - 1 - i); -+#ifdef CONFIG_SCHED_SMT -+ if (static_branch_likely(&sched_smt_present) && -+ IDLE_TASK_SCHED_PRIO == watermark) { -+ cpumask_t tmp; -+ -+ cpumask_and(&tmp, cpu_smt_mask(cpu), sched_rq_watermark); -+ if (cpumask_equal(&tmp, cpu_smt_mask(cpu))) -+ cpumask_or(&sched_sg_idle_mask, -+ &sched_sg_idle_mask, cpu_smt_mask(cpu)); -+ } -+#endif -+} -+ -+/* -+ * This routine assume that the idle task always in queue -+ */ -+static inline struct task_struct *sched_rq_first_task(struct rq *rq) -+{ -+ unsigned long idx = find_first_bit(rq->queue.bitmap, SCHED_QUEUE_BITS); -+ const struct list_head *head = &rq->queue.heads[sched_prio2idx(idx, rq)]; -+ -+ return list_first_entry(head, struct task_struct, sq_node); -+} -+ -+static inline struct task_struct * -+sched_rq_next_task(struct task_struct *p, struct rq *rq) -+{ -+ unsigned long idx = p->sq_idx; -+ struct list_head *head = &rq->queue.heads[idx]; -+ -+ if (list_is_last(&p->sq_node, head)) { -+ idx = find_next_bit(rq->queue.bitmap, SCHED_QUEUE_BITS, -+ sched_idx2prio(idx, rq) + 1); -+ head = &rq->queue.heads[sched_prio2idx(idx, rq)]; -+ -+ return list_first_entry(head, struct task_struct, sq_node); -+ } -+ -+ return list_next_entry(p, sq_node); -+} -+ -+static inline struct task_struct *rq_runnable_task(struct rq *rq) -+{ -+ struct task_struct *next = sched_rq_first_task(rq); -+ -+ if (unlikely(next == rq->skip)) -+ next = sched_rq_next_task(next, rq); -+ -+ return next; -+} -+ -+/* -+ * Serialization rules: -+ * -+ * Lock order: -+ * -+ * p->pi_lock -+ * rq->lock -+ * hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls) -+ * -+ * rq1->lock -+ * rq2->lock where: rq1 < rq2 -+ * -+ * Regular state: -+ * -+ * Normal scheduling state is serialized by rq->lock. __schedule() takes the -+ * local CPU's rq->lock, it optionally removes the task from the runqueue and -+ * always looks at the local rq data structures to find the most eligible task -+ * to run next. -+ * -+ * Task enqueue is also under rq->lock, possibly taken from another CPU. -+ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to -+ * the local CPU to avoid bouncing the runqueue state around [ see -+ * ttwu_queue_wakelist() ] -+ * -+ * Task wakeup, specifically wakeups that involve migration, are horribly -+ * complicated to avoid having to take two rq->locks. -+ * -+ * Special state: -+ * -+ * System-calls and anything external will use task_rq_lock() which acquires -+ * both p->pi_lock and rq->lock. As a consequence the state they change is -+ * stable while holding either lock: -+ * -+ * - sched_setaffinity()/ -+ * set_cpus_allowed_ptr(): p->cpus_ptr, p->nr_cpus_allowed -+ * - set_user_nice(): p->se.load, p->*prio -+ * - __sched_setscheduler(): p->sched_class, p->policy, p->*prio, -+ * p->se.load, p->rt_priority, -+ * p->dl.dl_{runtime, deadline, period, flags, bw, density} -+ * - sched_setnuma(): p->numa_preferred_nid -+ * - sched_move_task()/ -+ * cpu_cgroup_fork(): p->sched_task_group -+ * - uclamp_update_active() p->uclamp* -+ * -+ * p->state <- TASK_*: -+ * -+ * is changed locklessly using set_current_state(), __set_current_state() or -+ * set_special_state(), see their respective comments, or by -+ * try_to_wake_up(). This latter uses p->pi_lock to serialize against -+ * concurrent self. -+ * -+ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }: -+ * -+ * is set by activate_task() and cleared by deactivate_task(), under -+ * rq->lock. Non-zero indicates the task is runnable, the special -+ * ON_RQ_MIGRATING state is used for migration without holding both -+ * rq->locks. It indicates task_cpu() is not stable, see task_rq_lock(). -+ * -+ * p->on_cpu <- { 0, 1 }: -+ * -+ * is set by prepare_task() and cleared by finish_task() such that it will be -+ * set before p is scheduled-in and cleared after p is scheduled-out, both -+ * under rq->lock. Non-zero indicates the task is running on its CPU. -+ * -+ * [ The astute reader will observe that it is possible for two tasks on one -+ * CPU to have ->on_cpu = 1 at the same time. ] -+ * -+ * task_cpu(p): is changed by set_task_cpu(), the rules are: -+ * -+ * - Don't call set_task_cpu() on a blocked task: -+ * -+ * We don't care what CPU we're not running on, this simplifies hotplug, -+ * the CPU assignment of blocked tasks isn't required to be valid. -+ * -+ * - for try_to_wake_up(), called under p->pi_lock: -+ * -+ * This allows try_to_wake_up() to only take one rq->lock, see its comment. -+ * -+ * - for migration called under rq->lock: -+ * [ see task_on_rq_migrating() in task_rq_lock() ] -+ * -+ * o move_queued_task() -+ * o detach_task() -+ * -+ * - for migration called under double_rq_lock(): -+ * -+ * o __migrate_swap_task() -+ * o push_rt_task() / pull_rt_task() -+ * o push_dl_task() / pull_dl_task() -+ * o dl_task_offline_migration() -+ * -+ */ -+ -+/* -+ * Context: p->pi_lock -+ */ -+static inline struct rq -+*__task_access_lock(struct task_struct *p, raw_spinlock_t **plock) -+{ -+ struct rq *rq; -+ for (;;) { -+ rq = task_rq(p); -+ if (p->on_cpu || task_on_rq_queued(p)) { -+ raw_spin_lock(&rq->lock); -+ if (likely((p->on_cpu || task_on_rq_queued(p)) -+ && rq == task_rq(p))) { -+ *plock = &rq->lock; -+ return rq; -+ } -+ raw_spin_unlock(&rq->lock); -+ } else if (task_on_rq_migrating(p)) { -+ do { -+ cpu_relax(); -+ } while (unlikely(task_on_rq_migrating(p))); -+ } else { -+ *plock = NULL; -+ return rq; -+ } -+ } -+} -+ -+static inline void -+__task_access_unlock(struct task_struct *p, raw_spinlock_t *lock) -+{ -+ if (NULL != lock) -+ raw_spin_unlock(lock); -+} -+ -+static inline struct rq -+*task_access_lock_irqsave(struct task_struct *p, raw_spinlock_t **plock, -+ unsigned long *flags) -+{ -+ struct rq *rq; -+ for (;;) { -+ rq = task_rq(p); -+ if (p->on_cpu || task_on_rq_queued(p)) { -+ raw_spin_lock_irqsave(&rq->lock, *flags); -+ if (likely((p->on_cpu || task_on_rq_queued(p)) -+ && rq == task_rq(p))) { -+ *plock = &rq->lock; -+ return rq; -+ } -+ raw_spin_unlock_irqrestore(&rq->lock, *flags); -+ } else if (task_on_rq_migrating(p)) { -+ do { -+ cpu_relax(); -+ } while (unlikely(task_on_rq_migrating(p))); -+ } else { -+ raw_spin_lock_irqsave(&p->pi_lock, *flags); -+ if (likely(!p->on_cpu && !p->on_rq && -+ rq == task_rq(p))) { -+ *plock = &p->pi_lock; -+ return rq; -+ } -+ raw_spin_unlock_irqrestore(&p->pi_lock, *flags); -+ } -+ } -+} -+ -+static inline void -+task_access_unlock_irqrestore(struct task_struct *p, raw_spinlock_t *lock, -+ unsigned long *flags) -+{ -+ raw_spin_unlock_irqrestore(lock, *flags); -+} -+ -+/* -+ * __task_rq_lock - lock the rq @p resides on. -+ */ -+struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) -+ __acquires(rq->lock) -+{ -+ struct rq *rq; -+ -+ lockdep_assert_held(&p->pi_lock); -+ -+ for (;;) { -+ rq = task_rq(p); -+ raw_spin_lock(&rq->lock); -+ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) -+ return rq; -+ raw_spin_unlock(&rq->lock); -+ -+ while (unlikely(task_on_rq_migrating(p))) -+ cpu_relax(); -+ } -+} -+ -+/* -+ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. -+ */ -+struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) -+ __acquires(p->pi_lock) -+ __acquires(rq->lock) -+{ -+ struct rq *rq; -+ -+ for (;;) { -+ raw_spin_lock_irqsave(&p->pi_lock, rf->flags); -+ rq = task_rq(p); -+ raw_spin_lock(&rq->lock); -+ /* -+ * move_queued_task() task_rq_lock() -+ * -+ * ACQUIRE (rq->lock) -+ * [S] ->on_rq = MIGRATING [L] rq = task_rq() -+ * WMB (__set_task_cpu()) ACQUIRE (rq->lock); -+ * [S] ->cpu = new_cpu [L] task_rq() -+ * [L] ->on_rq -+ * RELEASE (rq->lock) -+ * -+ * If we observe the old CPU in task_rq_lock(), the acquire of -+ * the old rq->lock will fully serialize against the stores. -+ * -+ * If we observe the new CPU in task_rq_lock(), the address -+ * dependency headed by '[L] rq = task_rq()' and the acquire -+ * will pair with the WMB to ensure we then also see migrating. -+ */ -+ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { -+ return rq; -+ } -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); -+ -+ while (unlikely(task_on_rq_migrating(p))) -+ cpu_relax(); -+ } -+} -+ -+static inline void -+rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) -+ __acquires(rq->lock) -+{ -+ raw_spin_lock_irqsave(&rq->lock, rf->flags); -+} -+ -+static inline void -+rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) -+ __releases(rq->lock) -+{ -+ raw_spin_unlock_irqrestore(&rq->lock, rf->flags); -+} -+ -+void raw_spin_rq_lock_nested(struct rq *rq, int subclass) -+{ -+ raw_spinlock_t *lock; -+ -+ /* Matches synchronize_rcu() in __sched_core_enable() */ -+ preempt_disable(); -+ -+ for (;;) { -+ lock = __rq_lockp(rq); -+ raw_spin_lock_nested(lock, subclass); -+ if (likely(lock == __rq_lockp(rq))) { -+ /* preempt_count *MUST* be > 1 */ -+ preempt_enable_no_resched(); -+ return; -+ } -+ raw_spin_unlock(lock); -+ } -+} -+ -+void raw_spin_rq_unlock(struct rq *rq) -+{ -+ raw_spin_unlock(rq_lockp(rq)); -+} -+ -+/* -+ * RQ-clock updating methods: -+ */ -+ -+static void update_rq_clock_task(struct rq *rq, s64 delta) -+{ -+/* -+ * In theory, the compile should just see 0 here, and optimize out the call -+ * to sched_rt_avg_update. But I don't trust it... -+ */ -+ s64 __maybe_unused steal = 0, irq_delta = 0; -+ -+#ifdef CONFIG_IRQ_TIME_ACCOUNTING -+ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; -+ -+ /* -+ * Since irq_time is only updated on {soft,}irq_exit, we might run into -+ * this case when a previous update_rq_clock() happened inside a -+ * {soft,}irq region. -+ * -+ * When this happens, we stop ->clock_task and only update the -+ * prev_irq_time stamp to account for the part that fit, so that a next -+ * update will consume the rest. This ensures ->clock_task is -+ * monotonic. -+ * -+ * It does however cause some slight miss-attribution of {soft,}irq -+ * time, a more accurate solution would be to update the irq_time using -+ * the current rq->clock timestamp, except that would require using -+ * atomic ops. -+ */ -+ if (irq_delta > delta) -+ irq_delta = delta; -+ -+ rq->prev_irq_time += irq_delta; -+ delta -= irq_delta; -+#endif -+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING -+ if (static_key_false((¶virt_steal_rq_enabled))) { -+ steal = paravirt_steal_clock(cpu_of(rq)); -+ steal -= rq->prev_steal_time_rq; -+ -+ if (unlikely(steal > delta)) -+ steal = delta; -+ -+ rq->prev_steal_time_rq += steal; -+ delta -= steal; -+ } -+#endif -+ -+ rq->clock_task += delta; -+ -+#ifdef CONFIG_HAVE_SCHED_AVG_IRQ -+ if ((irq_delta + steal)) -+ update_irq_load_avg(rq, irq_delta + steal); -+#endif -+} -+ -+static inline void update_rq_clock(struct rq *rq) -+{ -+ s64 delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; -+ -+ if (unlikely(delta <= 0)) -+ return; -+ rq->clock += delta; -+ update_rq_time_edge(rq); -+ update_rq_clock_task(rq, delta); -+} -+ -+/* -+ * RQ Load update routine -+ */ -+#define RQ_LOAD_HISTORY_BITS (sizeof(s32) * 8ULL) -+#define RQ_UTIL_SHIFT (8) -+#define RQ_LOAD_HISTORY_TO_UTIL(l) (((l) >> (RQ_LOAD_HISTORY_BITS - 1 - RQ_UTIL_SHIFT)) & 0xff) -+ -+#define LOAD_BLOCK(t) ((t) >> 17) -+#define LOAD_HALF_BLOCK(t) ((t) >> 16) -+#define BLOCK_MASK(t) ((t) & ((0x01 << 18) - 1)) -+#define LOAD_BLOCK_BIT(b) (1UL << (RQ_LOAD_HISTORY_BITS - 1 - (b))) -+#define CURRENT_LOAD_BIT LOAD_BLOCK_BIT(0) -+ -+static inline void rq_load_update(struct rq *rq) -+{ -+ u64 time = rq->clock; -+ u64 delta = min(LOAD_BLOCK(time) - LOAD_BLOCK(rq->load_stamp), -+ RQ_LOAD_HISTORY_BITS - 1); -+ u64 prev = !!(rq->load_history & CURRENT_LOAD_BIT); -+ u64 curr = !!rq->nr_running; -+ -+ if (delta) { -+ rq->load_history = rq->load_history >> delta; -+ -+ if (delta < RQ_UTIL_SHIFT) { -+ rq->load_block += (~BLOCK_MASK(rq->load_stamp)) * prev; -+ if (!!LOAD_HALF_BLOCK(rq->load_block) ^ curr) -+ rq->load_history ^= LOAD_BLOCK_BIT(delta); -+ } -+ -+ rq->load_block = BLOCK_MASK(time) * prev; -+ } else { -+ rq->load_block += (time - rq->load_stamp) * prev; -+ } -+ if (prev ^ curr) -+ rq->load_history ^= CURRENT_LOAD_BIT; -+ rq->load_stamp = time; -+} -+ -+unsigned long rq_load_util(struct rq *rq, unsigned long max) -+{ -+ return RQ_LOAD_HISTORY_TO_UTIL(rq->load_history) * (max >> RQ_UTIL_SHIFT); -+} -+ -+#ifdef CONFIG_SMP -+unsigned long sched_cpu_util(int cpu, unsigned long max) -+{ -+ return rq_load_util(cpu_rq(cpu), max); -+} -+#endif /* CONFIG_SMP */ -+ -+#ifdef CONFIG_CPU_FREQ -+/** -+ * cpufreq_update_util - Take a note about CPU utilization changes. -+ * @rq: Runqueue to carry out the update for. -+ * @flags: Update reason flags. -+ * -+ * This function is called by the scheduler on the CPU whose utilization is -+ * being updated. -+ * -+ * It can only be called from RCU-sched read-side critical sections. -+ * -+ * The way cpufreq is currently arranged requires it to evaluate the CPU -+ * performance state (frequency/voltage) on a regular basis to prevent it from -+ * being stuck in a completely inadequate performance level for too long. -+ * That is not guaranteed to happen if the updates are only triggered from CFS -+ * and DL, though, because they may not be coming in if only RT tasks are -+ * active all the time (or there are RT tasks only). -+ * -+ * As a workaround for that issue, this function is called periodically by the -+ * RT sched class to trigger extra cpufreq updates to prevent it from stalling, -+ * but that really is a band-aid. Going forward it should be replaced with -+ * solutions targeted more specifically at RT tasks. -+ */ -+static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) -+{ -+ struct update_util_data *data; -+ -+#ifdef CONFIG_SMP -+ rq_load_update(rq); -+#endif -+ data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, -+ cpu_of(rq))); -+ if (data) -+ data->func(data, rq_clock(rq), flags); -+} -+#else -+static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) -+{ -+#ifdef CONFIG_SMP -+ rq_load_update(rq); -+#endif -+} -+#endif /* CONFIG_CPU_FREQ */ -+ -+#ifdef CONFIG_NO_HZ_FULL -+/* -+ * Tick may be needed by tasks in the runqueue depending on their policy and -+ * requirements. If tick is needed, lets send the target an IPI to kick it out -+ * of nohz mode if necessary. -+ */ -+static inline void sched_update_tick_dependency(struct rq *rq) -+{ -+ int cpu = cpu_of(rq); -+ -+ if (!tick_nohz_full_cpu(cpu)) -+ return; -+ -+ if (rq->nr_running < 2) -+ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); -+ else -+ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); -+} -+#else /* !CONFIG_NO_HZ_FULL */ -+static inline void sched_update_tick_dependency(struct rq *rq) { } -+#endif -+ -+bool sched_task_on_rq(struct task_struct *p) -+{ -+ return task_on_rq_queued(p); -+} -+ -+/* -+ * Add/Remove/Requeue task to/from the runqueue routines -+ * Context: rq->lock -+ */ -+#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \ -+ psi_dequeue(p, flags & DEQUEUE_SLEEP); \ -+ sched_info_dequeue(rq, p); \ -+ \ -+ list_del(&p->sq_node); \ -+ if (list_empty(&rq->queue.heads[p->sq_idx])) { \ -+ clear_bit(sched_idx2prio(p->sq_idx, rq), \ -+ rq->queue.bitmap); \ -+ func; \ -+ } -+ -+#define __SCHED_ENQUEUE_TASK(p, rq, flags) \ -+ sched_info_enqueue(rq, p); \ -+ psi_enqueue(p, flags); \ -+ \ -+ p->sq_idx = task_sched_prio_idx(p, rq); \ -+ list_add_tail(&p->sq_node, &rq->queue.heads[p->sq_idx]); \ -+ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); -+ -+static inline void dequeue_task(struct task_struct *p, struct rq *rq, int flags) -+{ -+ lockdep_assert_held(&rq->lock); -+ -+ /*printk(KERN_INFO "sched: dequeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ -+ WARN_ONCE(task_rq(p) != rq, "sched: dequeue task reside on cpu%d from cpu%d\n", -+ task_cpu(p), cpu_of(rq)); -+ -+ __SCHED_DEQUEUE_TASK(p, rq, flags, update_sched_rq_watermark(rq)); -+ --rq->nr_running; -+#ifdef CONFIG_SMP -+ if (1 == rq->nr_running) -+ cpumask_clear_cpu(cpu_of(rq), &sched_rq_pending_mask); -+#endif -+ -+ sched_update_tick_dependency(rq); -+} -+ -+static inline void enqueue_task(struct task_struct *p, struct rq *rq, int flags) -+{ -+ lockdep_assert_held(&rq->lock); -+ -+ /*printk(KERN_INFO "sched: enqueue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ -+ WARN_ONCE(task_rq(p) != rq, "sched: enqueue task reside on cpu%d to cpu%d\n", -+ task_cpu(p), cpu_of(rq)); -+ -+ __SCHED_ENQUEUE_TASK(p, rq, flags); -+ update_sched_rq_watermark(rq); -+ ++rq->nr_running; -+#ifdef CONFIG_SMP -+ if (2 == rq->nr_running) -+ cpumask_set_cpu(cpu_of(rq), &sched_rq_pending_mask); -+#endif -+ -+ sched_update_tick_dependency(rq); -+} -+ -+static inline void requeue_task(struct task_struct *p, struct rq *rq) -+{ -+ int idx; -+ -+ lockdep_assert_held(&rq->lock); -+ /*printk(KERN_INFO "sched: requeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ -+ WARN_ONCE(task_rq(p) != rq, "sched: cpu[%d] requeue task reside on cpu%d\n", -+ cpu_of(rq), task_cpu(p)); -+ -+ idx = task_sched_prio_idx(p, rq); -+ -+ list_del(&p->sq_node); -+ list_add_tail(&p->sq_node, &rq->queue.heads[idx]); -+ if (idx != p->sq_idx) { -+ if (list_empty(&rq->queue.heads[p->sq_idx])) -+ clear_bit(sched_idx2prio(p->sq_idx, rq), -+ rq->queue.bitmap); -+ p->sq_idx = idx; -+ set_bit(sched_idx2prio(p->sq_idx, rq), rq->queue.bitmap); -+ update_sched_rq_watermark(rq); -+ } -+} -+ -+/* -+ * cmpxchg based fetch_or, macro so it works for different integer types -+ */ -+#define fetch_or(ptr, mask) \ -+ ({ \ -+ typeof(ptr) _ptr = (ptr); \ -+ typeof(mask) _mask = (mask); \ -+ typeof(*_ptr) _old, _val = *_ptr; \ -+ \ -+ for (;;) { \ -+ _old = cmpxchg(_ptr, _val, _val | _mask); \ -+ if (_old == _val) \ -+ break; \ -+ _val = _old; \ -+ } \ -+ _old; \ -+}) -+ -+#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) -+/* -+ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, -+ * this avoids any races wrt polling state changes and thereby avoids -+ * spurious IPIs. -+ */ -+static bool set_nr_and_not_polling(struct task_struct *p) -+{ -+ struct thread_info *ti = task_thread_info(p); -+ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); -+} -+ -+/* -+ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. -+ * -+ * If this returns true, then the idle task promises to call -+ * sched_ttwu_pending() and reschedule soon. -+ */ -+static bool set_nr_if_polling(struct task_struct *p) -+{ -+ struct thread_info *ti = task_thread_info(p); -+ typeof(ti->flags) old, val = READ_ONCE(ti->flags); -+ -+ for (;;) { -+ if (!(val & _TIF_POLLING_NRFLAG)) -+ return false; -+ if (val & _TIF_NEED_RESCHED) -+ return true; -+ old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); -+ if (old == val) -+ break; -+ val = old; -+ } -+ return true; -+} -+ -+#else -+static bool set_nr_and_not_polling(struct task_struct *p) -+{ -+ set_tsk_need_resched(p); -+ return true; -+} -+ -+#ifdef CONFIG_SMP -+static bool set_nr_if_polling(struct task_struct *p) -+{ -+ return false; -+} -+#endif -+#endif -+ -+static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) -+{ -+ struct wake_q_node *node = &task->wake_q; -+ -+ /* -+ * Atomically grab the task, if ->wake_q is !nil already it means -+ * it's already queued (either by us or someone else) and will get the -+ * wakeup due to that. -+ * -+ * In order to ensure that a pending wakeup will observe our pending -+ * state, even in the failed case, an explicit smp_mb() must be used. -+ */ -+ smp_mb__before_atomic(); -+ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) -+ return false; -+ -+ /* -+ * The head is context local, there can be no concurrency. -+ */ -+ *head->lastp = node; -+ head->lastp = &node->next; -+ return true; -+} -+ -+/** -+ * wake_q_add() - queue a wakeup for 'later' waking. -+ * @head: the wake_q_head to add @task to -+ * @task: the task to queue for 'later' wakeup -+ * -+ * Queue a task for later wakeup, most likely by the wake_up_q() call in the -+ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come -+ * instantly. -+ * -+ * This function must be used as-if it were wake_up_process(); IOW the task -+ * must be ready to be woken at this location. -+ */ -+void wake_q_add(struct wake_q_head *head, struct task_struct *task) -+{ -+ if (__wake_q_add(head, task)) -+ get_task_struct(task); -+} -+ -+/** -+ * wake_q_add_safe() - safely queue a wakeup for 'later' waking. -+ * @head: the wake_q_head to add @task to -+ * @task: the task to queue for 'later' wakeup -+ * -+ * Queue a task for later wakeup, most likely by the wake_up_q() call in the -+ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come -+ * instantly. -+ * -+ * This function must be used as-if it were wake_up_process(); IOW the task -+ * must be ready to be woken at this location. -+ * -+ * This function is essentially a task-safe equivalent to wake_q_add(). Callers -+ * that already hold reference to @task can call the 'safe' version and trust -+ * wake_q to do the right thing depending whether or not the @task is already -+ * queued for wakeup. -+ */ -+void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task) -+{ -+ if (!__wake_q_add(head, task)) -+ put_task_struct(task); -+} -+ -+void wake_up_q(struct wake_q_head *head) -+{ -+ struct wake_q_node *node = head->first; -+ -+ while (node != WAKE_Q_TAIL) { -+ struct task_struct *task; -+ -+ task = container_of(node, struct task_struct, wake_q); -+ /* task can safely be re-inserted now: */ -+ node = node->next; -+ task->wake_q.next = NULL; -+ -+ /* -+ * wake_up_process() executes a full barrier, which pairs with -+ * the queueing in wake_q_add() so as not to miss wakeups. -+ */ -+ wake_up_process(task); -+ put_task_struct(task); -+ } -+} -+ -+/* -+ * resched_curr - mark rq's current task 'to be rescheduled now'. -+ * -+ * On UP this means the setting of the need_resched flag, on SMP it -+ * might also involve a cross-CPU call to trigger the scheduler on -+ * the target CPU. -+ */ -+void resched_curr(struct rq *rq) -+{ -+ struct task_struct *curr = rq->curr; -+ int cpu; -+ -+ lockdep_assert_held(&rq->lock); -+ -+ if (test_tsk_need_resched(curr)) -+ return; -+ -+ cpu = cpu_of(rq); -+ if (cpu == smp_processor_id()) { -+ set_tsk_need_resched(curr); -+ set_preempt_need_resched(); -+ return; -+ } -+ -+ if (set_nr_and_not_polling(curr)) -+ smp_send_reschedule(cpu); -+ else -+ trace_sched_wake_idle_without_ipi(cpu); -+} -+ -+void resched_cpu(int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ if (cpu_online(cpu) || cpu == smp_processor_id()) -+ resched_curr(cpu_rq(cpu)); -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+} -+ -+#ifdef CONFIG_SMP -+#ifdef CONFIG_NO_HZ_COMMON -+void nohz_balance_enter_idle(int cpu) {} -+ -+void select_nohz_load_balancer(int stop_tick) {} -+ -+void set_cpu_sd_state_idle(void) {} -+ -+/* -+ * In the semi idle case, use the nearest busy CPU for migrating timers -+ * from an idle CPU. This is good for power-savings. -+ * -+ * We don't do similar optimization for completely idle system, as -+ * selecting an idle CPU will add more delays to the timers than intended -+ * (as that CPU's timer base may not be uptodate wrt jiffies etc). -+ */ -+int get_nohz_timer_target(void) -+{ -+ int i, cpu = smp_processor_id(), default_cpu = -1; -+ struct cpumask *mask; -+ const struct cpumask *hk_mask; -+ -+ if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) { -+ if (!idle_cpu(cpu)) -+ return cpu; -+ default_cpu = cpu; -+ } -+ -+ hk_mask = housekeeping_cpumask(HK_FLAG_TIMER); -+ -+ for (mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; -+ mask < per_cpu(sched_cpu_topo_end_mask, cpu); mask++) -+ for_each_cpu_and(i, mask, hk_mask) -+ if (!idle_cpu(i)) -+ return i; -+ -+ if (default_cpu == -1) -+ default_cpu = housekeeping_any_cpu(HK_FLAG_TIMER); -+ cpu = default_cpu; -+ -+ return cpu; -+} -+ -+/* -+ * When add_timer_on() enqueues a timer into the timer wheel of an -+ * idle CPU then this timer might expire before the next timer event -+ * which is scheduled to wake up that CPU. In case of a completely -+ * idle system the next event might even be infinite time into the -+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and -+ * leaves the inner idle loop so the newly added timer is taken into -+ * account when the CPU goes back to idle and evaluates the timer -+ * wheel for the next timer event. -+ */ -+static inline void wake_up_idle_cpu(int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ if (cpu == smp_processor_id()) -+ return; -+ -+ if (set_nr_and_not_polling(rq->idle)) -+ smp_send_reschedule(cpu); -+ else -+ trace_sched_wake_idle_without_ipi(cpu); -+} -+ -+static inline bool wake_up_full_nohz_cpu(int cpu) -+{ -+ /* -+ * We just need the target to call irq_exit() and re-evaluate -+ * the next tick. The nohz full kick at least implies that. -+ * If needed we can still optimize that later with an -+ * empty IRQ. -+ */ -+ if (cpu_is_offline(cpu)) -+ return true; /* Don't try to wake offline CPUs. */ -+ if (tick_nohz_full_cpu(cpu)) { -+ if (cpu != smp_processor_id() || -+ tick_nohz_tick_stopped()) -+ tick_nohz_full_kick_cpu(cpu); -+ return true; -+ } -+ -+ return false; -+} -+ -+void wake_up_nohz_cpu(int cpu) -+{ -+ if (!wake_up_full_nohz_cpu(cpu)) -+ wake_up_idle_cpu(cpu); -+} -+ -+static void nohz_csd_func(void *info) -+{ -+ struct rq *rq = info; -+ int cpu = cpu_of(rq); -+ unsigned int flags; -+ -+ /* -+ * Release the rq::nohz_csd. -+ */ -+ flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu)); -+ WARN_ON(!(flags & NOHZ_KICK_MASK)); -+ -+ rq->idle_balance = idle_cpu(cpu); -+ if (rq->idle_balance && !need_resched()) { -+ rq->nohz_idle_balance = flags; -+ raise_softirq_irqoff(SCHED_SOFTIRQ); -+ } -+} -+ -+#endif /* CONFIG_NO_HZ_COMMON */ -+#endif /* CONFIG_SMP */ -+ -+static inline void check_preempt_curr(struct rq *rq) -+{ -+ if (sched_rq_first_task(rq) != rq->curr) -+ resched_curr(rq); -+} -+ -+#ifdef CONFIG_SCHED_HRTICK -+/* -+ * Use HR-timers to deliver accurate preemption points. -+ */ -+ -+static void hrtick_clear(struct rq *rq) -+{ -+ if (hrtimer_active(&rq->hrtick_timer)) -+ hrtimer_cancel(&rq->hrtick_timer); -+} -+ -+/* -+ * High-resolution timer tick. -+ * Runs from hardirq context with interrupts disabled. -+ */ -+static enum hrtimer_restart hrtick(struct hrtimer *timer) -+{ -+ struct rq *rq = container_of(timer, struct rq, hrtick_timer); -+ -+ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); -+ -+ raw_spin_lock(&rq->lock); -+ resched_curr(rq); -+ raw_spin_unlock(&rq->lock); -+ -+ return HRTIMER_NORESTART; -+} -+ -+/* -+ * Use hrtick when: -+ * - enabled by features -+ * - hrtimer is actually high res -+ */ -+static inline int hrtick_enabled(struct rq *rq) -+{ -+ /** -+ * Alt schedule FW doesn't support sched_feat yet -+ if (!sched_feat(HRTICK)) -+ return 0; -+ */ -+ if (!cpu_active(cpu_of(rq))) -+ return 0; -+ return hrtimer_is_hres_active(&rq->hrtick_timer); -+} -+ -+#ifdef CONFIG_SMP -+ -+static void __hrtick_restart(struct rq *rq) -+{ -+ struct hrtimer *timer = &rq->hrtick_timer; -+ ktime_t time = rq->hrtick_time; -+ -+ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD); -+} -+ -+/* -+ * called from hardirq (IPI) context -+ */ -+static void __hrtick_start(void *arg) -+{ -+ struct rq *rq = arg; -+ -+ raw_spin_lock(&rq->lock); -+ __hrtick_restart(rq); -+ raw_spin_unlock(&rq->lock); -+} -+ -+/* -+ * Called to set the hrtick timer state. -+ * -+ * called with rq->lock held and irqs disabled -+ */ -+void hrtick_start(struct rq *rq, u64 delay) -+{ -+ struct hrtimer *timer = &rq->hrtick_timer; -+ s64 delta; -+ -+ /* -+ * Don't schedule slices shorter than 10000ns, that just -+ * doesn't make sense and can cause timer DoS. -+ */ -+ delta = max_t(s64, delay, 10000LL); -+ -+ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta); -+ -+ if (rq == this_rq()) -+ __hrtick_restart(rq); -+ else -+ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); -+} -+ -+#else -+/* -+ * Called to set the hrtick timer state. -+ * -+ * called with rq->lock held and irqs disabled -+ */ -+void hrtick_start(struct rq *rq, u64 delay) -+{ -+ /* -+ * Don't schedule slices shorter than 10000ns, that just -+ * doesn't make sense. Rely on vruntime for fairness. -+ */ -+ delay = max_t(u64, delay, 10000LL); -+ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), -+ HRTIMER_MODE_REL_PINNED_HARD); -+} -+#endif /* CONFIG_SMP */ -+ -+static void hrtick_rq_init(struct rq *rq) -+{ -+#ifdef CONFIG_SMP -+ INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq); -+#endif -+ -+ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); -+ rq->hrtick_timer.function = hrtick; -+} -+#else /* CONFIG_SCHED_HRTICK */ -+static inline int hrtick_enabled(struct rq *rq) -+{ -+ return 0; -+} -+ -+static inline void hrtick_clear(struct rq *rq) -+{ -+} -+ -+static inline void hrtick_rq_init(struct rq *rq) -+{ -+} -+#endif /* CONFIG_SCHED_HRTICK */ -+ -+static inline int __normal_prio(int policy, int rt_prio, int static_prio) -+{ -+ return rt_policy(policy) ? (MAX_RT_PRIO - 1 - rt_prio) : -+ static_prio + MAX_PRIORITY_ADJ; -+} -+ -+/* -+ * Calculate the expected normal priority: i.e. priority -+ * without taking RT-inheritance into account. Might be -+ * boosted by interactivity modifiers. Changes upon fork, -+ * setprio syscalls, and whenever the interactivity -+ * estimator recalculates. -+ */ -+static inline int normal_prio(struct task_struct *p) -+{ -+ return __normal_prio(p->policy, p->rt_priority, p->static_prio); -+} -+ -+/* -+ * Calculate the current priority, i.e. the priority -+ * taken into account by the scheduler. This value might -+ * be boosted by RT tasks as it will be RT if the task got -+ * RT-boosted. If not then it returns p->normal_prio. -+ */ -+static int effective_prio(struct task_struct *p) -+{ -+ p->normal_prio = normal_prio(p); -+ /* -+ * If we are RT tasks or we were boosted to RT priority, -+ * keep the priority unchanged. Otherwise, update priority -+ * to the normal priority: -+ */ -+ if (!rt_prio(p->prio)) -+ return p->normal_prio; -+ return p->prio; -+} -+ -+/* -+ * activate_task - move a task to the runqueue. -+ * -+ * Context: rq->lock -+ */ -+static void activate_task(struct task_struct *p, struct rq *rq) -+{ -+ enqueue_task(p, rq, ENQUEUE_WAKEUP); -+ p->on_rq = TASK_ON_RQ_QUEUED; -+ -+ /* -+ * If in_iowait is set, the code below may not trigger any cpufreq -+ * utilization updates, so do it here explicitly with the IOWAIT flag -+ * passed. -+ */ -+ cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT * p->in_iowait); -+} -+ -+/* -+ * deactivate_task - remove a task from the runqueue. -+ * -+ * Context: rq->lock -+ */ -+static inline void deactivate_task(struct task_struct *p, struct rq *rq) -+{ -+ dequeue_task(p, rq, DEQUEUE_SLEEP); -+ p->on_rq = 0; -+ cpufreq_update_util(rq, 0); -+} -+ -+static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) -+{ -+#ifdef CONFIG_SMP -+ /* -+ * After ->cpu is set up to a new value, task_access_lock(p, ...) can be -+ * successfully executed on another CPU. We must ensure that updates of -+ * per-task data have been completed by this moment. -+ */ -+ smp_wmb(); -+ -+#ifdef CONFIG_THREAD_INFO_IN_TASK -+ WRITE_ONCE(p->cpu, cpu); -+#else -+ WRITE_ONCE(task_thread_info(p)->cpu, cpu); -+#endif -+#endif -+} -+ -+static inline bool is_migration_disabled(struct task_struct *p) -+{ -+#ifdef CONFIG_SMP -+ return p->migration_disabled; -+#else -+ return false; -+#endif -+} -+ -+#define SCA_CHECK 0x01 -+#define SCA_USER 0x08 -+ -+#ifdef CONFIG_SMP -+ -+void set_task_cpu(struct task_struct *p, unsigned int new_cpu) -+{ -+#ifdef CONFIG_SCHED_DEBUG -+ unsigned int state = READ_ONCE(p->__state); -+ -+ /* -+ * We should never call set_task_cpu() on a blocked task, -+ * ttwu() will sort out the placement. -+ */ -+ WARN_ON_ONCE(state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq); -+ -+#ifdef CONFIG_LOCKDEP -+ /* -+ * The caller should hold either p->pi_lock or rq->lock, when changing -+ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. -+ * -+ * sched_move_task() holds both and thus holding either pins the cgroup, -+ * see task_group(). -+ */ -+ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || -+ lockdep_is_held(&task_rq(p)->lock))); -+#endif -+ /* -+ * Clearly, migrating tasks to offline CPUs is a fairly daft thing. -+ */ -+ WARN_ON_ONCE(!cpu_online(new_cpu)); -+ -+ WARN_ON_ONCE(is_migration_disabled(p)); -+#endif -+ if (task_cpu(p) == new_cpu) -+ return; -+ trace_sched_migrate_task(p, new_cpu); -+ rseq_migrate(p); -+ perf_event_task_migrate(p); -+ -+ __set_task_cpu(p, new_cpu); -+} -+ -+#define MDF_FORCE_ENABLED 0x80 -+ -+static void -+__do_set_cpus_ptr(struct task_struct *p, const struct cpumask *new_mask) -+{ -+ /* -+ * This here violates the locking rules for affinity, since we're only -+ * supposed to change these variables while holding both rq->lock and -+ * p->pi_lock. -+ * -+ * HOWEVER, it magically works, because ttwu() is the only code that -+ * accesses these variables under p->pi_lock and only does so after -+ * smp_cond_load_acquire(&p->on_cpu, !VAL), and we're in __schedule() -+ * before finish_task(). -+ * -+ * XXX do further audits, this smells like something putrid. -+ */ -+ SCHED_WARN_ON(!p->on_cpu); -+ p->cpus_ptr = new_mask; -+} -+ -+void migrate_disable(void) -+{ -+ struct task_struct *p = current; -+ int cpu; -+ -+ if (p->migration_disabled) { -+ p->migration_disabled++; -+ return; -+ } -+ -+ preempt_disable(); -+ cpu = smp_processor_id(); -+ if (cpumask_test_cpu(cpu, &p->cpus_mask)) { -+ cpu_rq(cpu)->nr_pinned++; -+ p->migration_disabled = 1; -+ p->migration_flags &= ~MDF_FORCE_ENABLED; -+ -+ /* -+ * Violates locking rules! see comment in __do_set_cpus_ptr(). -+ */ -+ if (p->cpus_ptr == &p->cpus_mask) -+ __do_set_cpus_ptr(p, cpumask_of(cpu)); -+ } -+ preempt_enable(); -+} -+EXPORT_SYMBOL_GPL(migrate_disable); -+ -+void migrate_enable(void) -+{ -+ struct task_struct *p = current; -+ -+ if (0 == p->migration_disabled) -+ return; -+ -+ if (p->migration_disabled > 1) { -+ p->migration_disabled--; -+ return; -+ } -+ -+ /* -+ * Ensure stop_task runs either before or after this, and that -+ * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule(). -+ */ -+ preempt_disable(); -+ /* -+ * Assumption: current should be running on allowed cpu -+ */ -+ WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask)); -+ if (p->cpus_ptr != &p->cpus_mask) -+ __do_set_cpus_ptr(p, &p->cpus_mask); -+ /* -+ * Mustn't clear migration_disabled() until cpus_ptr points back at the -+ * regular cpus_mask, otherwise things that race (eg. -+ * select_fallback_rq) get confused. -+ */ -+ barrier(); -+ p->migration_disabled = 0; -+ this_rq()->nr_pinned--; -+ preempt_enable(); -+} -+EXPORT_SYMBOL_GPL(migrate_enable); -+ -+static inline bool rq_has_pinned_tasks(struct rq *rq) -+{ -+ return rq->nr_pinned; -+} -+ -+/* -+ * Per-CPU kthreads are allowed to run on !active && online CPUs, see -+ * __set_cpus_allowed_ptr() and select_fallback_rq(). -+ */ -+static inline bool is_cpu_allowed(struct task_struct *p, int cpu) -+{ -+ /* When not in the task's cpumask, no point in looking further. */ -+ if (!cpumask_test_cpu(cpu, p->cpus_ptr)) -+ return false; -+ -+ /* migrate_disabled() must be allowed to finish. */ -+ if (is_migration_disabled(p)) -+ return cpu_online(cpu); -+ -+ /* Non kernel threads are not allowed during either online or offline. */ -+ if (!(p->flags & PF_KTHREAD)) -+ return cpu_active(cpu) && task_cpu_possible(cpu, p); -+ -+ /* KTHREAD_IS_PER_CPU is always allowed. */ -+ if (kthread_is_per_cpu(p)) -+ return cpu_online(cpu); -+ -+ /* Regular kernel threads don't get to stay during offline. */ -+ if (cpu_dying(cpu)) -+ return false; -+ -+ /* But are allowed during online. */ -+ return cpu_online(cpu); -+} -+ -+/* -+ * This is how migration works: -+ * -+ * 1) we invoke migration_cpu_stop() on the target CPU using -+ * stop_one_cpu(). -+ * 2) stopper starts to run (implicitly forcing the migrated thread -+ * off the CPU) -+ * 3) it checks whether the migrated task is still in the wrong runqueue. -+ * 4) if it's in the wrong runqueue then the migration thread removes -+ * it and puts it into the right queue. -+ * 5) stopper completes and stop_one_cpu() returns and the migration -+ * is done. -+ */ -+ -+/* -+ * move_queued_task - move a queued task to new rq. -+ * -+ * Returns (locked) new rq. Old rq's lock is released. -+ */ -+static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int -+ new_cpu) -+{ -+ lockdep_assert_held(&rq->lock); -+ -+ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING); -+ dequeue_task(p, rq, 0); -+ set_task_cpu(p, new_cpu); -+ raw_spin_unlock(&rq->lock); -+ -+ rq = cpu_rq(new_cpu); -+ -+ raw_spin_lock(&rq->lock); -+ BUG_ON(task_cpu(p) != new_cpu); -+ sched_task_sanity_check(p, rq); -+ enqueue_task(p, rq, 0); -+ p->on_rq = TASK_ON_RQ_QUEUED; -+ check_preempt_curr(rq); -+ -+ return rq; -+} -+ -+struct migration_arg { -+ struct task_struct *task; -+ int dest_cpu; -+}; -+ -+/* -+ * Move (not current) task off this CPU, onto the destination CPU. We're doing -+ * this because either it can't run here any more (set_cpus_allowed() -+ * away from this CPU, or CPU going down), or because we're -+ * attempting to rebalance this task on exec (sched_exec). -+ * -+ * So we race with normal scheduler movements, but that's OK, as long -+ * as the task is no longer on this CPU. -+ */ -+static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int -+ dest_cpu) -+{ -+ /* Affinity changed (again). */ -+ if (!is_cpu_allowed(p, dest_cpu)) -+ return rq; -+ -+ update_rq_clock(rq); -+ return move_queued_task(rq, p, dest_cpu); -+} -+ -+/* -+ * migration_cpu_stop - this will be executed by a highprio stopper thread -+ * and performs thread migration by bumping thread off CPU then -+ * 'pushing' onto another runqueue. -+ */ -+static int migration_cpu_stop(void *data) -+{ -+ struct migration_arg *arg = data; -+ struct task_struct *p = arg->task; -+ struct rq *rq = this_rq(); -+ unsigned long flags; -+ -+ /* -+ * The original target CPU might have gone down and we might -+ * be on another CPU but it doesn't matter. -+ */ -+ local_irq_save(flags); -+ /* -+ * We need to explicitly wake pending tasks before running -+ * __migrate_task() such that we will not miss enforcing cpus_ptr -+ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. -+ */ -+ flush_smp_call_function_from_idle(); -+ -+ raw_spin_lock(&p->pi_lock); -+ raw_spin_lock(&rq->lock); -+ /* -+ * If task_rq(p) != rq, it cannot be migrated here, because we're -+ * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because -+ * we're holding p->pi_lock. -+ */ -+ if (task_rq(p) == rq && task_on_rq_queued(p)) -+ rq = __migrate_task(rq, p, arg->dest_cpu); -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ -+ return 0; -+} -+ -+static inline void -+set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) -+{ -+ cpumask_copy(&p->cpus_mask, new_mask); -+ p->nr_cpus_allowed = cpumask_weight(new_mask); -+} -+ -+static void -+__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) -+{ -+ lockdep_assert_held(&p->pi_lock); -+ set_cpus_allowed_common(p, new_mask); -+} -+ -+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) -+{ -+ __do_set_cpus_allowed(p, new_mask); -+} -+ -+int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, -+ int node) -+{ -+ if (!src->user_cpus_ptr) -+ return 0; -+ -+ dst->user_cpus_ptr = kmalloc_node(cpumask_size(), GFP_KERNEL, node); -+ if (!dst->user_cpus_ptr) -+ return -ENOMEM; -+ -+ cpumask_copy(dst->user_cpus_ptr, src->user_cpus_ptr); -+ return 0; -+} -+ -+static inline struct cpumask *clear_user_cpus_ptr(struct task_struct *p) -+{ -+ struct cpumask *user_mask = NULL; -+ -+ swap(p->user_cpus_ptr, user_mask); -+ -+ return user_mask; -+} -+ -+void release_user_cpus_ptr(struct task_struct *p) -+{ -+ kfree(clear_user_cpus_ptr(p)); -+} -+ -+#endif -+ -+/** -+ * task_curr - is this task currently executing on a CPU? -+ * @p: the task in question. -+ * -+ * Return: 1 if the task is currently executing. 0 otherwise. -+ */ -+inline int task_curr(const struct task_struct *p) -+{ -+ return cpu_curr(task_cpu(p)) == p; -+} -+ -+#ifdef CONFIG_SMP -+/* -+ * wait_task_inactive - wait for a thread to unschedule. -+ * -+ * If @match_state is nonzero, it's the @p->state value just checked and -+ * not expected to change. If it changes, i.e. @p might have woken up, -+ * then return zero. When we succeed in waiting for @p to be off its CPU, -+ * we return a positive number (its total switch count). If a second call -+ * a short while later returns the same number, the caller can be sure that -+ * @p has remained unscheduled the whole time. -+ * -+ * The caller must ensure that the task *will* unschedule sometime soon, -+ * else this function might spin for a *long* time. This function can't -+ * be called with interrupts off, or it may introduce deadlock with -+ * smp_call_function() if an IPI is sent by the same process we are -+ * waiting to become inactive. -+ */ -+unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state) -+{ -+ unsigned long flags; -+ bool running, on_rq; -+ unsigned long ncsw; -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ -+ for (;;) { -+ rq = task_rq(p); -+ -+ /* -+ * If the task is actively running on another CPU -+ * still, just relax and busy-wait without holding -+ * any locks. -+ * -+ * NOTE! Since we don't hold any locks, it's not -+ * even sure that "rq" stays as the right runqueue! -+ * But we don't care, since this will return false -+ * if the runqueue has changed and p is actually now -+ * running somewhere else! -+ */ -+ while (task_running(p) && p == rq->curr) { -+ if (match_state && unlikely(READ_ONCE(p->__state) != match_state)) -+ return 0; -+ cpu_relax(); -+ } -+ -+ /* -+ * Ok, time to look more closely! We need the rq -+ * lock now, to be *sure*. If we're wrong, we'll -+ * just go back and repeat. -+ */ -+ task_access_lock_irqsave(p, &lock, &flags); -+ trace_sched_wait_task(p); -+ running = task_running(p); -+ on_rq = p->on_rq; -+ ncsw = 0; -+ if (!match_state || READ_ONCE(p->__state) == match_state) -+ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ -+ task_access_unlock_irqrestore(p, lock, &flags); -+ -+ /* -+ * If it changed from the expected state, bail out now. -+ */ -+ if (unlikely(!ncsw)) -+ break; -+ -+ /* -+ * Was it really running after all now that we -+ * checked with the proper locks actually held? -+ * -+ * Oops. Go back and try again.. -+ */ -+ if (unlikely(running)) { -+ cpu_relax(); -+ continue; -+ } -+ -+ /* -+ * It's not enough that it's not actively running, -+ * it must be off the runqueue _entirely_, and not -+ * preempted! -+ * -+ * So if it was still runnable (but just not actively -+ * running right now), it's preempted, and we should -+ * yield - it could be a while. -+ */ -+ if (unlikely(on_rq)) { -+ ktime_t to = NSEC_PER_SEC / HZ; -+ -+ set_current_state(TASK_UNINTERRUPTIBLE); -+ schedule_hrtimeout(&to, HRTIMER_MODE_REL); -+ continue; -+ } -+ -+ /* -+ * Ahh, all good. It wasn't running, and it wasn't -+ * runnable, which means that it will never become -+ * running in the future either. We're all done! -+ */ -+ break; -+ } -+ -+ return ncsw; -+} -+ -+/*** -+ * kick_process - kick a running thread to enter/exit the kernel -+ * @p: the to-be-kicked thread -+ * -+ * Cause a process which is running on another CPU to enter -+ * kernel-mode, without any delay. (to get signals handled.) -+ * -+ * NOTE: this function doesn't have to take the runqueue lock, -+ * because all it wants to ensure is that the remote task enters -+ * the kernel. If the IPI races and the task has been migrated -+ * to another CPU then no harm is done and the purpose has been -+ * achieved as well. -+ */ -+void kick_process(struct task_struct *p) -+{ -+ int cpu; -+ -+ preempt_disable(); -+ cpu = task_cpu(p); -+ if ((cpu != smp_processor_id()) && task_curr(p)) -+ smp_send_reschedule(cpu); -+ preempt_enable(); -+} -+EXPORT_SYMBOL_GPL(kick_process); -+ -+/* -+ * ->cpus_ptr is protected by both rq->lock and p->pi_lock -+ * -+ * A few notes on cpu_active vs cpu_online: -+ * -+ * - cpu_active must be a subset of cpu_online -+ * -+ * - on CPU-up we allow per-CPU kthreads on the online && !active CPU, -+ * see __set_cpus_allowed_ptr(). At this point the newly online -+ * CPU isn't yet part of the sched domains, and balancing will not -+ * see it. -+ * -+ * - on cpu-down we clear cpu_active() to mask the sched domains and -+ * avoid the load balancer to place new tasks on the to be removed -+ * CPU. Existing tasks will remain running there and will be taken -+ * off. -+ * -+ * This means that fallback selection must not select !active CPUs. -+ * And can assume that any active CPU must be online. Conversely -+ * select_task_rq() below may allow selection of !active CPUs in order -+ * to satisfy the above rules. -+ */ -+static int select_fallback_rq(int cpu, struct task_struct *p) -+{ -+ int nid = cpu_to_node(cpu); -+ const struct cpumask *nodemask = NULL; -+ enum { cpuset, possible, fail } state = cpuset; -+ int dest_cpu; -+ -+ /* -+ * If the node that the CPU is on has been offlined, cpu_to_node() -+ * will return -1. There is no CPU on the node, and we should -+ * select the CPU on the other node. -+ */ -+ if (nid != -1) { -+ nodemask = cpumask_of_node(nid); -+ -+ /* Look for allowed, online CPU in same node. */ -+ for_each_cpu(dest_cpu, nodemask) { -+ if (is_cpu_allowed(p, dest_cpu)) -+ return dest_cpu; -+ } -+ } -+ -+ for (;;) { -+ /* Any allowed, online CPU? */ -+ for_each_cpu(dest_cpu, p->cpus_ptr) { -+ if (!is_cpu_allowed(p, dest_cpu)) -+ continue; -+ goto out; -+ } -+ -+ /* No more Mr. Nice Guy. */ -+ switch (state) { -+ case cpuset: -+ if (cpuset_cpus_allowed_fallback(p)) { -+ state = possible; -+ break; -+ } -+ fallthrough; -+ case possible: -+ /* -+ * XXX When called from select_task_rq() we only -+ * hold p->pi_lock and again violate locking order. -+ * -+ * More yuck to audit. -+ */ -+ do_set_cpus_allowed(p, task_cpu_possible_mask(p)); -+ state = fail; -+ break; -+ -+ case fail: -+ BUG(); -+ break; -+ } -+ } -+ -+out: -+ if (state != cpuset) { -+ /* -+ * Don't tell them about moving exiting tasks or -+ * kernel threads (both mm NULL), since they never -+ * leave kernel. -+ */ -+ if (p->mm && printk_ratelimit()) { -+ printk_deferred("process %d (%s) no longer affine to cpu%d\n", -+ task_pid_nr(p), p->comm, cpu); -+ } -+ } -+ -+ return dest_cpu; -+} -+ -+static inline int select_task_rq(struct task_struct *p) -+{ -+ cpumask_t chk_mask, tmp; -+ -+ if (unlikely(!cpumask_and(&chk_mask, p->cpus_ptr, cpu_active_mask))) -+ return select_fallback_rq(task_cpu(p), p); -+ -+ if ( -+#ifdef CONFIG_SCHED_SMT -+ cpumask_and(&tmp, &chk_mask, &sched_sg_idle_mask) || -+#endif -+ cpumask_and(&tmp, &chk_mask, sched_rq_watermark) || -+ cpumask_and(&tmp, &chk_mask, -+ sched_rq_watermark + SCHED_BITS - task_sched_prio(p))) -+ return best_mask_cpu(task_cpu(p), &tmp); -+ -+ return best_mask_cpu(task_cpu(p), &chk_mask); -+} -+ -+void sched_set_stop_task(int cpu, struct task_struct *stop) -+{ -+ static struct lock_class_key stop_pi_lock; -+ struct sched_param stop_param = { .sched_priority = STOP_PRIO }; -+ struct sched_param start_param = { .sched_priority = 0 }; -+ struct task_struct *old_stop = cpu_rq(cpu)->stop; -+ -+ if (stop) { -+ /* -+ * Make it appear like a SCHED_FIFO task, its something -+ * userspace knows about and won't get confused about. -+ * -+ * Also, it will make PI more or less work without too -+ * much confusion -- but then, stop work should not -+ * rely on PI working anyway. -+ */ -+ sched_setscheduler_nocheck(stop, SCHED_FIFO, &stop_param); -+ -+ /* -+ * The PI code calls rt_mutex_setprio() with ->pi_lock held to -+ * adjust the effective priority of a task. As a result, -+ * rt_mutex_setprio() can trigger (RT) balancing operations, -+ * which can then trigger wakeups of the stop thread to push -+ * around the current task. -+ * -+ * The stop task itself will never be part of the PI-chain, it -+ * never blocks, therefore that ->pi_lock recursion is safe. -+ * Tell lockdep about this by placing the stop->pi_lock in its -+ * own class. -+ */ -+ lockdep_set_class(&stop->pi_lock, &stop_pi_lock); -+ } -+ -+ cpu_rq(cpu)->stop = stop; -+ -+ if (old_stop) { -+ /* -+ * Reset it back to a normal scheduling policy so that -+ * it can die in pieces. -+ */ -+ sched_setscheduler_nocheck(old_stop, SCHED_NORMAL, &start_param); -+ } -+} -+ -+static int affine_move_task(struct rq *rq, struct task_struct *p, int dest_cpu, -+ raw_spinlock_t *lock, unsigned long irq_flags) -+{ -+ /* Can the task run on the task's current CPU? If so, we're done */ -+ if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) { -+ if (p->migration_disabled) { -+ if (likely(p->cpus_ptr != &p->cpus_mask)) -+ __do_set_cpus_ptr(p, &p->cpus_mask); -+ p->migration_disabled = 0; -+ p->migration_flags |= MDF_FORCE_ENABLED; -+ /* When p is migrate_disabled, rq->lock should be held */ -+ rq->nr_pinned--; -+ } -+ -+ if (task_running(p) || READ_ONCE(p->__state) == TASK_WAKING) { -+ struct migration_arg arg = { p, dest_cpu }; -+ -+ /* Need help from migration thread: drop lock and wait. */ -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); -+ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); -+ return 0; -+ } -+ if (task_on_rq_queued(p)) { -+ /* -+ * OK, since we're going to drop the lock immediately -+ * afterwards anyway. -+ */ -+ update_rq_clock(rq); -+ rq = move_queued_task(rq, p, dest_cpu); -+ lock = &rq->lock; -+ } -+ } -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); -+ return 0; -+} -+ -+static int __set_cpus_allowed_ptr_locked(struct task_struct *p, -+ const struct cpumask *new_mask, -+ u32 flags, -+ struct rq *rq, -+ raw_spinlock_t *lock, -+ unsigned long irq_flags) -+{ -+ const struct cpumask *cpu_allowed_mask = task_cpu_possible_mask(p); -+ const struct cpumask *cpu_valid_mask = cpu_active_mask; -+ bool kthread = p->flags & PF_KTHREAD; -+ struct cpumask *user_mask = NULL; -+ int dest_cpu; -+ int ret = 0; -+ -+ if (kthread || is_migration_disabled(p)) { -+ /* -+ * Kernel threads are allowed on online && !active CPUs, -+ * however, during cpu-hot-unplug, even these might get pushed -+ * away if not KTHREAD_IS_PER_CPU. -+ * -+ * Specifically, migration_disabled() tasks must not fail the -+ * cpumask_any_and_distribute() pick below, esp. so on -+ * SCA_MIGRATE_ENABLE, otherwise we'll not call -+ * set_cpus_allowed_common() and actually reset p->cpus_ptr. -+ */ -+ cpu_valid_mask = cpu_online_mask; -+ } -+ -+ if (!kthread && !cpumask_subset(new_mask, cpu_allowed_mask)) { -+ ret = -EINVAL; -+ goto out; -+ } -+ -+ /* -+ * Must re-check here, to close a race against __kthread_bind(), -+ * sched_setaffinity() is not guaranteed to observe the flag. -+ */ -+ if ((flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) { -+ ret = -EINVAL; -+ goto out; -+ } -+ -+ if (cpumask_equal(&p->cpus_mask, new_mask)) -+ goto out; -+ -+ dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); -+ if (dest_cpu >= nr_cpu_ids) { -+ ret = -EINVAL; -+ goto out; -+ } -+ -+ __do_set_cpus_allowed(p, new_mask); -+ -+ if (flags & SCA_USER) -+ user_mask = clear_user_cpus_ptr(p); -+ -+ ret = affine_move_task(rq, p, dest_cpu, lock, irq_flags); -+ -+ kfree(user_mask); -+ -+ return ret; -+ -+out: -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); -+ -+ return ret; -+} -+ -+/* -+ * Change a given task's CPU affinity. Migrate the thread to a -+ * proper CPU and schedule it away if the CPU it's executing on -+ * is removed from the allowed bitmask. -+ * -+ * NOTE: the caller must have a valid reference to the task, the -+ * task must not exit() & deallocate itself prematurely. The -+ * call is not atomic; no spinlocks may be held. -+ */ -+static int __set_cpus_allowed_ptr(struct task_struct *p, -+ const struct cpumask *new_mask, u32 flags) -+{ -+ unsigned long irq_flags; -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ -+ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); -+ rq = __task_access_lock(p, &lock); -+ -+ return __set_cpus_allowed_ptr_locked(p, new_mask, flags, rq, lock, irq_flags); -+} -+ -+int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) -+{ -+ return __set_cpus_allowed_ptr(p, new_mask, 0); -+} -+EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); -+ -+/* -+ * Change a given task's CPU affinity to the intersection of its current -+ * affinity mask and @subset_mask, writing the resulting mask to @new_mask -+ * and pointing @p->user_cpus_ptr to a copy of the old mask. -+ * If the resulting mask is empty, leave the affinity unchanged and return -+ * -EINVAL. -+ */ -+static int restrict_cpus_allowed_ptr(struct task_struct *p, -+ struct cpumask *new_mask, -+ const struct cpumask *subset_mask) -+{ -+ struct cpumask *user_mask = NULL; -+ unsigned long irq_flags; -+ raw_spinlock_t *lock; -+ struct rq *rq; -+ int err; -+ -+ if (!p->user_cpus_ptr) { -+ user_mask = kmalloc(cpumask_size(), GFP_KERNEL); -+ if (!user_mask) -+ return -ENOMEM; -+ } -+ -+ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); -+ rq = __task_access_lock(p, &lock); -+ -+ if (!cpumask_and(new_mask, &p->cpus_mask, subset_mask)) { -+ err = -EINVAL; -+ goto err_unlock; -+ } -+ -+ /* -+ * We're about to butcher the task affinity, so keep track of what -+ * the user asked for in case we're able to restore it later on. -+ */ -+ if (user_mask) { -+ cpumask_copy(user_mask, p->cpus_ptr); -+ p->user_cpus_ptr = user_mask; -+ } -+ -+ /*return __set_cpus_allowed_ptr_locked(p, new_mask, 0, rq, &rf);*/ -+ return __set_cpus_allowed_ptr_locked(p, new_mask, 0, rq, lock, irq_flags); -+ -+err_unlock: -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); -+ kfree(user_mask); -+ return err; -+} -+ -+/* -+ * Restrict the CPU affinity of task @p so that it is a subset of -+ * task_cpu_possible_mask() and point @p->user_cpu_ptr to a copy of the -+ * old affinity mask. If the resulting mask is empty, we warn and walk -+ * up the cpuset hierarchy until we find a suitable mask. -+ */ -+void force_compatible_cpus_allowed_ptr(struct task_struct *p) -+{ -+ cpumask_var_t new_mask; -+ const struct cpumask *override_mask = task_cpu_possible_mask(p); -+ -+ alloc_cpumask_var(&new_mask, GFP_KERNEL); -+ -+ /* -+ * __migrate_task() can fail silently in the face of concurrent -+ * offlining of the chosen destination CPU, so take the hotplug -+ * lock to ensure that the migration succeeds. -+ */ -+ cpus_read_lock(); -+ if (!cpumask_available(new_mask)) -+ goto out_set_mask; -+ -+ if (!restrict_cpus_allowed_ptr(p, new_mask, override_mask)) -+ goto out_free_mask; -+ -+ /* -+ * We failed to find a valid subset of the affinity mask for the -+ * task, so override it based on its cpuset hierarchy. -+ */ -+ cpuset_cpus_allowed(p, new_mask); -+ override_mask = new_mask; -+ -+out_set_mask: -+ if (printk_ratelimit()) { -+ printk_deferred("Overriding affinity for process %d (%s) to CPUs %*pbl\n", -+ task_pid_nr(p), p->comm, -+ cpumask_pr_args(override_mask)); -+ } -+ -+ WARN_ON(set_cpus_allowed_ptr(p, override_mask)); -+out_free_mask: -+ cpus_read_unlock(); -+ free_cpumask_var(new_mask); -+} -+ -+static int -+__sched_setaffinity(struct task_struct *p, const struct cpumask *mask); -+ -+/* -+ * Restore the affinity of a task @p which was previously restricted by a -+ * call to force_compatible_cpus_allowed_ptr(). This will clear (and free) -+ * @p->user_cpus_ptr. -+ * -+ * It is the caller's responsibility to serialise this with any calls to -+ * force_compatible_cpus_allowed_ptr(@p). -+ */ -+void relax_compatible_cpus_allowed_ptr(struct task_struct *p) -+{ -+ struct cpumask *user_mask = p->user_cpus_ptr; -+ unsigned long flags; -+ -+ /* -+ * Try to restore the old affinity mask. If this fails, then -+ * we free the mask explicitly to avoid it being inherited across -+ * a subsequent fork(). -+ */ -+ if (!user_mask || !__sched_setaffinity(p, user_mask)) -+ return; -+ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ user_mask = clear_user_cpus_ptr(p); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ -+ kfree(user_mask); -+} -+ -+#else /* CONFIG_SMP */ -+ -+static inline int select_task_rq(struct task_struct *p) -+{ -+ return 0; -+} -+ -+static inline int -+__set_cpus_allowed_ptr(struct task_struct *p, -+ const struct cpumask *new_mask, u32 flags) -+{ -+ return set_cpus_allowed_ptr(p, new_mask); -+} -+ -+static inline bool rq_has_pinned_tasks(struct rq *rq) -+{ -+ return false; -+} -+ -+#endif /* !CONFIG_SMP */ -+ -+static void -+ttwu_stat(struct task_struct *p, int cpu, int wake_flags) -+{ -+ struct rq *rq; -+ -+ if (!schedstat_enabled()) -+ return; -+ -+ rq = this_rq(); -+ -+#ifdef CONFIG_SMP -+ if (cpu == rq->cpu) -+ __schedstat_inc(rq->ttwu_local); -+ else { -+ /** Alt schedule FW ToDo: -+ * How to do ttwu_wake_remote -+ */ -+ } -+#endif /* CONFIG_SMP */ -+ -+ __schedstat_inc(rq->ttwu_count); -+} -+ -+/* -+ * Mark the task runnable and perform wakeup-preemption. -+ */ -+static inline void -+ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) -+{ -+ check_preempt_curr(rq); -+ WRITE_ONCE(p->__state, TASK_RUNNING); -+ trace_sched_wakeup(p); -+} -+ -+static inline void -+ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) -+{ -+ if (p->sched_contributes_to_load) -+ rq->nr_uninterruptible--; -+ -+ if ( -+#ifdef CONFIG_SMP -+ !(wake_flags & WF_MIGRATED) && -+#endif -+ p->in_iowait) { -+ delayacct_blkio_end(p); -+ atomic_dec(&task_rq(p)->nr_iowait); -+ } -+ -+ activate_task(p, rq); -+ ttwu_do_wakeup(rq, p, 0); -+} -+ -+/* -+ * Consider @p being inside a wait loop: -+ * -+ * for (;;) { -+ * set_current_state(TASK_UNINTERRUPTIBLE); -+ * -+ * if (CONDITION) -+ * break; -+ * -+ * schedule(); -+ * } -+ * __set_current_state(TASK_RUNNING); -+ * -+ * between set_current_state() and schedule(). In this case @p is still -+ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in -+ * an atomic manner. -+ * -+ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq -+ * then schedule() must still happen and p->state can be changed to -+ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we -+ * need to do a full wakeup with enqueue. -+ * -+ * Returns: %true when the wakeup is done, -+ * %false otherwise. -+ */ -+static int ttwu_runnable(struct task_struct *p, int wake_flags) -+{ -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ int ret = 0; -+ -+ rq = __task_access_lock(p, &lock); -+ if (task_on_rq_queued(p)) { -+ /* check_preempt_curr() may use rq clock */ -+ update_rq_clock(rq); -+ ttwu_do_wakeup(rq, p, wake_flags); -+ ret = 1; -+ } -+ __task_access_unlock(p, lock); -+ -+ return ret; -+} -+ -+#ifdef CONFIG_SMP -+void sched_ttwu_pending(void *arg) -+{ -+ struct llist_node *llist = arg; -+ struct rq *rq = this_rq(); -+ struct task_struct *p, *t; -+ struct rq_flags rf; -+ -+ if (!llist) -+ return; -+ -+ /* -+ * rq::ttwu_pending racy indication of out-standing wakeups. -+ * Races such that false-negatives are possible, since they -+ * are shorter lived that false-positives would be. -+ */ -+ WRITE_ONCE(rq->ttwu_pending, 0); -+ -+ rq_lock_irqsave(rq, &rf); -+ update_rq_clock(rq); -+ -+ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) { -+ if (WARN_ON_ONCE(p->on_cpu)) -+ smp_cond_load_acquire(&p->on_cpu, !VAL); -+ -+ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq))) -+ set_task_cpu(p, cpu_of(rq)); -+ -+ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0); -+ } -+ -+ rq_unlock_irqrestore(rq, &rf); -+} -+ -+void send_call_function_single_ipi(int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ if (!set_nr_if_polling(rq->idle)) -+ arch_send_call_function_single_ipi(cpu); -+ else -+ trace_sched_wake_idle_without_ipi(cpu); -+} -+ -+/* -+ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if -+ * necessary. The wakee CPU on receipt of the IPI will queue the task -+ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost -+ * of the wakeup instead of the waker. -+ */ -+static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED); -+ -+ WRITE_ONCE(rq->ttwu_pending, 1); -+ __smp_call_single_queue(cpu, &p->wake_entry.llist); -+} -+ -+static inline bool ttwu_queue_cond(int cpu, int wake_flags) -+{ -+ /* -+ * Do not complicate things with the async wake_list while the CPU is -+ * in hotplug state. -+ */ -+ if (!cpu_active(cpu)) -+ return false; -+ -+ /* -+ * If the CPU does not share cache, then queue the task on the -+ * remote rqs wakelist to avoid accessing remote data. -+ */ -+ if (!cpus_share_cache(smp_processor_id(), cpu)) -+ return true; -+ -+ /* -+ * If the task is descheduling and the only running task on the -+ * CPU then use the wakelist to offload the task activation to -+ * the soon-to-be-idle CPU as the current CPU is likely busy. -+ * nr_running is checked to avoid unnecessary task stacking. -+ */ -+ if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1) -+ return true; -+ -+ return false; -+} -+ -+static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) -+{ -+ if (__is_defined(ALT_SCHED_TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) { -+ if (WARN_ON_ONCE(cpu == smp_processor_id())) -+ return false; -+ -+ sched_clock_cpu(cpu); /* Sync clocks across CPUs */ -+ __ttwu_queue_wakelist(p, cpu, wake_flags); -+ return true; -+ } -+ -+ return false; -+} -+ -+void wake_up_if_idle(int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ -+ rcu_read_lock(); -+ -+ if (!is_idle_task(rcu_dereference(rq->curr))) -+ goto out; -+ -+ if (set_nr_if_polling(rq->idle)) { -+ trace_sched_wake_idle_without_ipi(cpu); -+ } else { -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ if (is_idle_task(rq->curr)) -+ smp_send_reschedule(cpu); -+ /* Else CPU is not idle, do nothing here */ -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ } -+ -+out: -+ rcu_read_unlock(); -+} -+ -+bool cpus_share_cache(int this_cpu, int that_cpu) -+{ -+ return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); -+} -+#else /* !CONFIG_SMP */ -+ -+static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) -+{ -+ return false; -+} -+ -+#endif /* CONFIG_SMP */ -+ -+static inline void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ if (ttwu_queue_wakelist(p, cpu, wake_flags)) -+ return; -+ -+ raw_spin_lock(&rq->lock); -+ update_rq_clock(rq); -+ ttwu_do_activate(rq, p, wake_flags); -+ raw_spin_unlock(&rq->lock); -+} -+ -+/* -+ * Invoked from try_to_wake_up() to check whether the task can be woken up. -+ * -+ * The caller holds p::pi_lock if p != current or has preemption -+ * disabled when p == current. -+ * -+ * The rules of PREEMPT_RT saved_state: -+ * -+ * The related locking code always holds p::pi_lock when updating -+ * p::saved_state, which means the code is fully serialized in both cases. -+ * -+ * The lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. No other -+ * bits set. This allows to distinguish all wakeup scenarios. -+ */ -+static __always_inline -+bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) -+{ -+ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT)) { -+ WARN_ON_ONCE((state & TASK_RTLOCK_WAIT) && -+ state != TASK_RTLOCK_WAIT); -+ } -+ -+ if (READ_ONCE(p->__state) & state) { -+ *success = 1; -+ return true; -+ } -+ -+#ifdef CONFIG_PREEMPT_RT -+ /* -+ * Saved state preserves the task state across blocking on -+ * an RT lock. If the state matches, set p::saved_state to -+ * TASK_RUNNING, but do not wake the task because it waits -+ * for a lock wakeup. Also indicate success because from -+ * the regular waker's point of view this has succeeded. -+ * -+ * After acquiring the lock the task will restore p::__state -+ * from p::saved_state which ensures that the regular -+ * wakeup is not lost. The restore will also set -+ * p::saved_state to TASK_RUNNING so any further tests will -+ * not result in false positives vs. @success -+ */ -+ if (p->saved_state & state) { -+ p->saved_state = TASK_RUNNING; -+ *success = 1; -+ } -+#endif -+ return false; -+} -+ -+/* -+ * Notes on Program-Order guarantees on SMP systems. -+ * -+ * MIGRATION -+ * -+ * The basic program-order guarantee on SMP systems is that when a task [t] -+ * migrates, all its activity on its old CPU [c0] happens-before any subsequent -+ * execution on its new CPU [c1]. -+ * -+ * For migration (of runnable tasks) this is provided by the following means: -+ * -+ * A) UNLOCK of the rq(c0)->lock scheduling out task t -+ * B) migration for t is required to synchronize *both* rq(c0)->lock and -+ * rq(c1)->lock (if not at the same time, then in that order). -+ * C) LOCK of the rq(c1)->lock scheduling in task -+ * -+ * Transitivity guarantees that B happens after A and C after B. -+ * Note: we only require RCpc transitivity. -+ * Note: the CPU doing B need not be c0 or c1 -+ * -+ * Example: -+ * -+ * CPU0 CPU1 CPU2 -+ * -+ * LOCK rq(0)->lock -+ * sched-out X -+ * sched-in Y -+ * UNLOCK rq(0)->lock -+ * -+ * LOCK rq(0)->lock // orders against CPU0 -+ * dequeue X -+ * UNLOCK rq(0)->lock -+ * -+ * LOCK rq(1)->lock -+ * enqueue X -+ * UNLOCK rq(1)->lock -+ * -+ * LOCK rq(1)->lock // orders against CPU2 -+ * sched-out Z -+ * sched-in X -+ * UNLOCK rq(1)->lock -+ * -+ * -+ * BLOCKING -- aka. SLEEP + WAKEUP -+ * -+ * For blocking we (obviously) need to provide the same guarantee as for -+ * migration. However the means are completely different as there is no lock -+ * chain to provide order. Instead we do: -+ * -+ * 1) smp_store_release(X->on_cpu, 0) -- finish_task() -+ * 2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up() -+ * -+ * Example: -+ * -+ * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule) -+ * -+ * LOCK rq(0)->lock LOCK X->pi_lock -+ * dequeue X -+ * sched-out X -+ * smp_store_release(X->on_cpu, 0); -+ * -+ * smp_cond_load_acquire(&X->on_cpu, !VAL); -+ * X->state = WAKING -+ * set_task_cpu(X,2) -+ * -+ * LOCK rq(2)->lock -+ * enqueue X -+ * X->state = RUNNING -+ * UNLOCK rq(2)->lock -+ * -+ * LOCK rq(2)->lock // orders against CPU1 -+ * sched-out Z -+ * sched-in X -+ * UNLOCK rq(2)->lock -+ * -+ * UNLOCK X->pi_lock -+ * UNLOCK rq(0)->lock -+ * -+ * -+ * However; for wakeups there is a second guarantee we must provide, namely we -+ * must observe the state that lead to our wakeup. That is, not only must our -+ * task observe its own prior state, it must also observe the stores prior to -+ * its wakeup. -+ * -+ * This means that any means of doing remote wakeups must order the CPU doing -+ * the wakeup against the CPU the task is going to end up running on. This, -+ * however, is already required for the regular Program-Order guarantee above, -+ * since the waking CPU is the one issueing the ACQUIRE (smp_cond_load_acquire). -+ * -+ */ -+ -+/** -+ * try_to_wake_up - wake up a thread -+ * @p: the thread to be awakened -+ * @state: the mask of task states that can be woken -+ * @wake_flags: wake modifier flags (WF_*) -+ * -+ * Conceptually does: -+ * -+ * If (@state & @p->state) @p->state = TASK_RUNNING. -+ * -+ * If the task was not queued/runnable, also place it back on a runqueue. -+ * -+ * This function is atomic against schedule() which would dequeue the task. -+ * -+ * It issues a full memory barrier before accessing @p->state, see the comment -+ * with set_current_state(). -+ * -+ * Uses p->pi_lock to serialize against concurrent wake-ups. -+ * -+ * Relies on p->pi_lock stabilizing: -+ * - p->sched_class -+ * - p->cpus_ptr -+ * - p->sched_task_group -+ * in order to do migration, see its use of select_task_rq()/set_task_cpu(). -+ * -+ * Tries really hard to only take one task_rq(p)->lock for performance. -+ * Takes rq->lock in: -+ * - ttwu_runnable() -- old rq, unavoidable, see comment there; -+ * - ttwu_queue() -- new rq, for enqueue of the task; -+ * - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us. -+ * -+ * As a consequence we race really badly with just about everything. See the -+ * many memory barriers and their comments for details. -+ * -+ * Return: %true if @p->state changes (an actual wakeup was done), -+ * %false otherwise. -+ */ -+static int try_to_wake_up(struct task_struct *p, unsigned int state, -+ int wake_flags) -+{ -+ unsigned long flags; -+ int cpu, success = 0; -+ -+ preempt_disable(); -+ if (p == current) { -+ /* -+ * We're waking current, this means 'p->on_rq' and 'task_cpu(p) -+ * == smp_processor_id()'. Together this means we can special -+ * case the whole 'p->on_rq && ttwu_runnable()' case below -+ * without taking any locks. -+ * -+ * In particular: -+ * - we rely on Program-Order guarantees for all the ordering, -+ * - we're serialized against set_special_state() by virtue of -+ * it disabling IRQs (this allows not taking ->pi_lock). -+ */ -+ if (!ttwu_state_match(p, state, &success)) -+ goto out; -+ -+ trace_sched_waking(p); -+ WRITE_ONCE(p->__state, TASK_RUNNING); -+ trace_sched_wakeup(p); -+ goto out; -+ } -+ -+ /* -+ * If we are going to wake up a thread waiting for CONDITION we -+ * need to ensure that CONDITION=1 done by the caller can not be -+ * reordered with p->state check below. This pairs with smp_store_mb() -+ * in set_current_state() that the waiting thread does. -+ */ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ smp_mb__after_spinlock(); -+ if (!ttwu_state_match(p, state, &success)) -+ goto unlock; -+ -+ trace_sched_waking(p); -+ -+ /* -+ * Ensure we load p->on_rq _after_ p->state, otherwise it would -+ * be possible to, falsely, observe p->on_rq == 0 and get stuck -+ * in smp_cond_load_acquire() below. -+ * -+ * sched_ttwu_pending() try_to_wake_up() -+ * STORE p->on_rq = 1 LOAD p->state -+ * UNLOCK rq->lock -+ * -+ * __schedule() (switch to task 'p') -+ * LOCK rq->lock smp_rmb(); -+ * smp_mb__after_spinlock(); -+ * UNLOCK rq->lock -+ * -+ * [task p] -+ * STORE p->state = UNINTERRUPTIBLE LOAD p->on_rq -+ * -+ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in -+ * __schedule(). See the comment for smp_mb__after_spinlock(). -+ * -+ * A similar smb_rmb() lives in try_invoke_on_locked_down_task(). -+ */ -+ smp_rmb(); -+ if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags)) -+ goto unlock; -+ -+#ifdef CONFIG_SMP -+ /* -+ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be -+ * possible to, falsely, observe p->on_cpu == 0. -+ * -+ * One must be running (->on_cpu == 1) in order to remove oneself -+ * from the runqueue. -+ * -+ * __schedule() (switch to task 'p') try_to_wake_up() -+ * STORE p->on_cpu = 1 LOAD p->on_rq -+ * UNLOCK rq->lock -+ * -+ * __schedule() (put 'p' to sleep) -+ * LOCK rq->lock smp_rmb(); -+ * smp_mb__after_spinlock(); -+ * STORE p->on_rq = 0 LOAD p->on_cpu -+ * -+ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in -+ * __schedule(). See the comment for smp_mb__after_spinlock(). -+ * -+ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure -+ * schedule()'s deactivate_task() has 'happened' and p will no longer -+ * care about it's own p->state. See the comment in __schedule(). -+ */ -+ smp_acquire__after_ctrl_dep(); -+ -+ /* -+ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq -+ * == 0), which means we need to do an enqueue, change p->state to -+ * TASK_WAKING such that we can unlock p->pi_lock before doing the -+ * enqueue, such as ttwu_queue_wakelist(). -+ */ -+ WRITE_ONCE(p->__state, TASK_WAKING); -+ -+ /* -+ * If the owning (remote) CPU is still in the middle of schedule() with -+ * this task as prev, considering queueing p on the remote CPUs wake_list -+ * which potentially sends an IPI instead of spinning on p->on_cpu to -+ * let the waker make forward progress. This is safe because IRQs are -+ * disabled and the IPI will deliver after on_cpu is cleared. -+ * -+ * Ensure we load task_cpu(p) after p->on_cpu: -+ * -+ * set_task_cpu(p, cpu); -+ * STORE p->cpu = @cpu -+ * __schedule() (switch to task 'p') -+ * LOCK rq->lock -+ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu) -+ * STORE p->on_cpu = 1 LOAD p->cpu -+ * -+ * to ensure we observe the correct CPU on which the task is currently -+ * scheduling. -+ */ -+ if (smp_load_acquire(&p->on_cpu) && -+ ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU)) -+ goto unlock; -+ -+ /* -+ * If the owning (remote) CPU is still in the middle of schedule() with -+ * this task as prev, wait until it's done referencing the task. -+ * -+ * Pairs with the smp_store_release() in finish_task(). -+ * -+ * This ensures that tasks getting woken will be fully ordered against -+ * their previous state and preserve Program Order. -+ */ -+ smp_cond_load_acquire(&p->on_cpu, !VAL); -+ -+ sched_task_ttwu(p); -+ -+ cpu = select_task_rq(p); -+ -+ if (cpu != task_cpu(p)) { -+ if (p->in_iowait) { -+ delayacct_blkio_end(p); -+ atomic_dec(&task_rq(p)->nr_iowait); -+ } -+ -+ wake_flags |= WF_MIGRATED; -+ psi_ttwu_dequeue(p); -+ set_task_cpu(p, cpu); -+ } -+#else -+ cpu = task_cpu(p); -+#endif /* CONFIG_SMP */ -+ -+ ttwu_queue(p, cpu, wake_flags); -+unlock: -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+out: -+ if (success) -+ ttwu_stat(p, task_cpu(p), wake_flags); -+ preempt_enable(); -+ -+ return success; -+} -+ -+/** -+ * try_invoke_on_locked_down_task - Invoke a function on task in fixed state -+ * @p: Process for which the function is to be invoked, can be @current. -+ * @func: Function to invoke. -+ * @arg: Argument to function. -+ * -+ * If the specified task can be quickly locked into a definite state -+ * (either sleeping or on a given runqueue), arrange to keep it in that -+ * state while invoking @func(@arg). This function can use ->on_rq and -+ * task_curr() to work out what the state is, if required. Given that -+ * @func can be invoked with a runqueue lock held, it had better be quite -+ * lightweight. -+ * -+ * Returns: -+ * @false if the task slipped out from under the locks. -+ * @true if the task was locked onto a runqueue or is sleeping. -+ * However, @func can override this by returning @false. -+ */ -+bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg) -+{ -+ struct rq_flags rf; -+ bool ret = false; -+ struct rq *rq; -+ -+ raw_spin_lock_irqsave(&p->pi_lock, rf.flags); -+ if (p->on_rq) { -+ rq = __task_rq_lock(p, &rf); -+ if (task_rq(p) == rq) -+ ret = func(p, arg); -+ __task_rq_unlock(rq, &rf); -+ } else { -+ switch (READ_ONCE(p->__state)) { -+ case TASK_RUNNING: -+ case TASK_WAKING: -+ break; -+ default: -+ smp_rmb(); // See smp_rmb() comment in try_to_wake_up(). -+ if (!p->on_rq) -+ ret = func(p, arg); -+ } -+ } -+ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); -+ return ret; -+} -+ -+/** -+ * wake_up_process - Wake up a specific process -+ * @p: The process to be woken up. -+ * -+ * Attempt to wake up the nominated process and move it to the set of runnable -+ * processes. -+ * -+ * Return: 1 if the process was woken up, 0 if it was already running. -+ * -+ * This function executes a full memory barrier before accessing the task state. -+ */ -+int wake_up_process(struct task_struct *p) -+{ -+ return try_to_wake_up(p, TASK_NORMAL, 0); -+} -+EXPORT_SYMBOL(wake_up_process); -+ -+int wake_up_state(struct task_struct *p, unsigned int state) -+{ -+ return try_to_wake_up(p, state, 0); -+} -+ -+/* -+ * Perform scheduler related setup for a newly forked process p. -+ * p is forked by current. -+ * -+ * __sched_fork() is basic setup used by init_idle() too: -+ */ -+static inline void __sched_fork(unsigned long clone_flags, struct task_struct *p) -+{ -+ p->on_rq = 0; -+ p->on_cpu = 0; -+ p->utime = 0; -+ p->stime = 0; -+ p->sched_time = 0; -+ -+#ifdef CONFIG_PREEMPT_NOTIFIERS -+ INIT_HLIST_HEAD(&p->preempt_notifiers); -+#endif -+ -+#ifdef CONFIG_COMPACTION -+ p->capture_control = NULL; -+#endif -+#ifdef CONFIG_SMP -+ p->wake_entry.u_flags = CSD_TYPE_TTWU; -+#endif -+} -+ -+/* -+ * fork()/clone()-time setup: -+ */ -+int sched_fork(unsigned long clone_flags, struct task_struct *p) -+{ -+ unsigned long flags; -+ struct rq *rq; -+ -+ __sched_fork(clone_flags, p); -+ /* -+ * We mark the process as NEW here. This guarantees that -+ * nobody will actually run it, and a signal or other external -+ * event cannot wake it up and insert it on the runqueue either. -+ */ -+ p->__state = TASK_NEW; -+ -+ /* -+ * Make sure we do not leak PI boosting priority to the child. -+ */ -+ p->prio = current->normal_prio; -+ -+ /* -+ * Revert to default priority/policy on fork if requested. -+ */ -+ if (unlikely(p->sched_reset_on_fork)) { -+ if (task_has_rt_policy(p)) { -+ p->policy = SCHED_NORMAL; -+ p->static_prio = NICE_TO_PRIO(0); -+ p->rt_priority = 0; -+ } else if (PRIO_TO_NICE(p->static_prio) < 0) -+ p->static_prio = NICE_TO_PRIO(0); -+ -+ p->prio = p->normal_prio = p->static_prio; -+ -+ /* -+ * We don't need the reset flag anymore after the fork. It has -+ * fulfilled its duty: -+ */ -+ p->sched_reset_on_fork = 0; -+ } -+ -+ /* -+ * The child is not yet in the pid-hash so no cgroup attach races, -+ * and the cgroup is pinned to this child due to cgroup_fork() -+ * is ran before sched_fork(). -+ * -+ * Silence PROVE_RCU. -+ */ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ /* -+ * Share the timeslice between parent and child, thus the -+ * total amount of pending timeslices in the system doesn't change, -+ * resulting in more scheduling fairness. -+ */ -+ rq = this_rq(); -+ raw_spin_lock(&rq->lock); -+ -+ rq->curr->time_slice /= 2; -+ p->time_slice = rq->curr->time_slice; -+#ifdef CONFIG_SCHED_HRTICK -+ hrtick_start(rq, rq->curr->time_slice); -+#endif -+ -+ if (p->time_slice < RESCHED_NS) { -+ p->time_slice = sched_timeslice_ns; -+ resched_curr(rq); -+ } -+ sched_task_fork(p, rq); -+ raw_spin_unlock(&rq->lock); -+ -+ rseq_migrate(p); -+ /* -+ * We're setting the CPU for the first time, we don't migrate, -+ * so use __set_task_cpu(). -+ */ -+ __set_task_cpu(p, cpu_of(rq)); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ -+#ifdef CONFIG_SCHED_INFO -+ if (unlikely(sched_info_on())) -+ memset(&p->sched_info, 0, sizeof(p->sched_info)); -+#endif -+ init_task_preempt_count(p); -+ -+ return 0; -+} -+ -+void sched_post_fork(struct task_struct *p) {} -+ -+#ifdef CONFIG_SCHEDSTATS -+ -+DEFINE_STATIC_KEY_FALSE(sched_schedstats); -+ -+static void set_schedstats(bool enabled) -+{ -+ if (enabled) -+ static_branch_enable(&sched_schedstats); -+ else -+ static_branch_disable(&sched_schedstats); -+} -+ -+void force_schedstat_enabled(void) -+{ -+ if (!schedstat_enabled()) { -+ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n"); -+ static_branch_enable(&sched_schedstats); -+ } -+} -+ -+static int __init setup_schedstats(char *str) -+{ -+ int ret = 0; -+ if (!str) -+ goto out; -+ -+ if (!strcmp(str, "enable")) { -+ set_schedstats(true); -+ ret = 1; -+ } else if (!strcmp(str, "disable")) { -+ set_schedstats(false); -+ ret = 1; -+ } -+out: -+ if (!ret) -+ pr_warn("Unable to parse schedstats=\n"); -+ -+ return ret; -+} -+__setup("schedstats=", setup_schedstats); -+ -+#ifdef CONFIG_PROC_SYSCTL -+int sysctl_schedstats(struct ctl_table *table, int write, -+ void __user *buffer, size_t *lenp, loff_t *ppos) -+{ -+ struct ctl_table t; -+ int err; -+ int state = static_branch_likely(&sched_schedstats); -+ -+ if (write && !capable(CAP_SYS_ADMIN)) -+ return -EPERM; -+ -+ t = *table; -+ t.data = &state; -+ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); -+ if (err < 0) -+ return err; -+ if (write) -+ set_schedstats(state); -+ return err; -+} -+#endif /* CONFIG_PROC_SYSCTL */ -+#endif /* CONFIG_SCHEDSTATS */ -+ -+/* -+ * wake_up_new_task - wake up a newly created task for the first time. -+ * -+ * This function will do some initial scheduler statistics housekeeping -+ * that must be done for every newly created context, then puts the task -+ * on the runqueue and wakes it. -+ */ -+void wake_up_new_task(struct task_struct *p) -+{ -+ unsigned long flags; -+ struct rq *rq; -+ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ WRITE_ONCE(p->__state, TASK_RUNNING); -+ rq = cpu_rq(select_task_rq(p)); -+#ifdef CONFIG_SMP -+ rseq_migrate(p); -+ /* -+ * Fork balancing, do it here and not earlier because: -+ * - cpus_ptr can change in the fork path -+ * - any previously selected CPU might disappear through hotplug -+ * -+ * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, -+ * as we're not fully set-up yet. -+ */ -+ __set_task_cpu(p, cpu_of(rq)); -+#endif -+ -+ raw_spin_lock(&rq->lock); -+ update_rq_clock(rq); -+ -+ activate_task(p, rq); -+ trace_sched_wakeup_new(p); -+ check_preempt_curr(rq); -+ -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+} -+ -+#ifdef CONFIG_PREEMPT_NOTIFIERS -+ -+static DEFINE_STATIC_KEY_FALSE(preempt_notifier_key); -+ -+void preempt_notifier_inc(void) -+{ -+ static_branch_inc(&preempt_notifier_key); -+} -+EXPORT_SYMBOL_GPL(preempt_notifier_inc); -+ -+void preempt_notifier_dec(void) -+{ -+ static_branch_dec(&preempt_notifier_key); -+} -+EXPORT_SYMBOL_GPL(preempt_notifier_dec); -+ -+/** -+ * preempt_notifier_register - tell me when current is being preempted & rescheduled -+ * @notifier: notifier struct to register -+ */ -+void preempt_notifier_register(struct preempt_notifier *notifier) -+{ -+ if (!static_branch_unlikely(&preempt_notifier_key)) -+ WARN(1, "registering preempt_notifier while notifiers disabled\n"); -+ -+ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); -+} -+EXPORT_SYMBOL_GPL(preempt_notifier_register); -+ -+/** -+ * preempt_notifier_unregister - no longer interested in preemption notifications -+ * @notifier: notifier struct to unregister -+ * -+ * This is *not* safe to call from within a preemption notifier. -+ */ -+void preempt_notifier_unregister(struct preempt_notifier *notifier) -+{ -+ hlist_del(¬ifier->link); -+} -+EXPORT_SYMBOL_GPL(preempt_notifier_unregister); -+ -+static void __fire_sched_in_preempt_notifiers(struct task_struct *curr) -+{ -+ struct preempt_notifier *notifier; -+ -+ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) -+ notifier->ops->sched_in(notifier, raw_smp_processor_id()); -+} -+ -+static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) -+{ -+ if (static_branch_unlikely(&preempt_notifier_key)) -+ __fire_sched_in_preempt_notifiers(curr); -+} -+ -+static void -+__fire_sched_out_preempt_notifiers(struct task_struct *curr, -+ struct task_struct *next) -+{ -+ struct preempt_notifier *notifier; -+ -+ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) -+ notifier->ops->sched_out(notifier, next); -+} -+ -+static __always_inline void -+fire_sched_out_preempt_notifiers(struct task_struct *curr, -+ struct task_struct *next) -+{ -+ if (static_branch_unlikely(&preempt_notifier_key)) -+ __fire_sched_out_preempt_notifiers(curr, next); -+} -+ -+#else /* !CONFIG_PREEMPT_NOTIFIERS */ -+ -+static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) -+{ -+} -+ -+static inline void -+fire_sched_out_preempt_notifiers(struct task_struct *curr, -+ struct task_struct *next) -+{ -+} -+ -+#endif /* CONFIG_PREEMPT_NOTIFIERS */ -+ -+static inline void prepare_task(struct task_struct *next) -+{ -+ /* -+ * Claim the task as running, we do this before switching to it -+ * such that any running task will have this set. -+ * -+ * See the ttwu() WF_ON_CPU case and its ordering comment. -+ */ -+ WRITE_ONCE(next->on_cpu, 1); -+} -+ -+static inline void finish_task(struct task_struct *prev) -+{ -+#ifdef CONFIG_SMP -+ /* -+ * This must be the very last reference to @prev from this CPU. After -+ * p->on_cpu is cleared, the task can be moved to a different CPU. We -+ * must ensure this doesn't happen until the switch is completely -+ * finished. -+ * -+ * In particular, the load of prev->state in finish_task_switch() must -+ * happen before this. -+ * -+ * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). -+ */ -+ smp_store_release(&prev->on_cpu, 0); -+#else -+ prev->on_cpu = 0; -+#endif -+} -+ -+#ifdef CONFIG_SMP -+ -+static void do_balance_callbacks(struct rq *rq, struct callback_head *head) -+{ -+ void (*func)(struct rq *rq); -+ struct callback_head *next; -+ -+ lockdep_assert_held(&rq->lock); -+ -+ while (head) { -+ func = (void (*)(struct rq *))head->func; -+ next = head->next; -+ head->next = NULL; -+ head = next; -+ -+ func(rq); -+ } -+} -+ -+static void balance_push(struct rq *rq); -+ -+struct callback_head balance_push_callback = { -+ .next = NULL, -+ .func = (void (*)(struct callback_head *))balance_push, -+}; -+ -+static inline struct callback_head *splice_balance_callbacks(struct rq *rq) -+{ -+ struct callback_head *head = rq->balance_callback; -+ -+ if (head) { -+ lockdep_assert_held(&rq->lock); -+ rq->balance_callback = NULL; -+ } -+ -+ return head; -+} -+ -+static void __balance_callbacks(struct rq *rq) -+{ -+ do_balance_callbacks(rq, splice_balance_callbacks(rq)); -+} -+ -+static inline void balance_callbacks(struct rq *rq, struct callback_head *head) -+{ -+ unsigned long flags; -+ -+ if (unlikely(head)) { -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ do_balance_callbacks(rq, head); -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ } -+} -+ -+#else -+ -+static inline void __balance_callbacks(struct rq *rq) -+{ -+} -+ -+static inline struct callback_head *splice_balance_callbacks(struct rq *rq) -+{ -+ return NULL; -+} -+ -+static inline void balance_callbacks(struct rq *rq, struct callback_head *head) -+{ -+} -+ -+#endif -+ -+static inline void -+prepare_lock_switch(struct rq *rq, struct task_struct *next) -+{ -+ /* -+ * Since the runqueue lock will be released by the next -+ * task (which is an invalid locking op but in the case -+ * of the scheduler it's an obvious special-case), so we -+ * do an early lockdep release here: -+ */ -+ spin_release(&rq->lock.dep_map, _THIS_IP_); -+#ifdef CONFIG_DEBUG_SPINLOCK -+ /* this is a valid case when another task releases the spinlock */ -+ rq->lock.owner = next; -+#endif -+} -+ -+static inline void finish_lock_switch(struct rq *rq) -+{ -+ /* -+ * If we are tracking spinlock dependencies then we have to -+ * fix up the runqueue lock - which gets 'carried over' from -+ * prev into current: -+ */ -+ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); -+ __balance_callbacks(rq); -+ raw_spin_unlock_irq(&rq->lock); -+} -+ -+/* -+ * NOP if the arch has not defined these: -+ */ -+ -+#ifndef prepare_arch_switch -+# define prepare_arch_switch(next) do { } while (0) -+#endif -+ -+#ifndef finish_arch_post_lock_switch -+# define finish_arch_post_lock_switch() do { } while (0) -+#endif -+ -+static inline void kmap_local_sched_out(void) -+{ -+#ifdef CONFIG_KMAP_LOCAL -+ if (unlikely(current->kmap_ctrl.idx)) -+ __kmap_local_sched_out(); -+#endif -+} -+ -+static inline void kmap_local_sched_in(void) -+{ -+#ifdef CONFIG_KMAP_LOCAL -+ if (unlikely(current->kmap_ctrl.idx)) -+ __kmap_local_sched_in(); -+#endif -+} -+ -+/** -+ * prepare_task_switch - prepare to switch tasks -+ * @rq: the runqueue preparing to switch -+ * @next: the task we are going to switch to. -+ * -+ * This is called with the rq lock held and interrupts off. It must -+ * be paired with a subsequent finish_task_switch after the context -+ * switch. -+ * -+ * prepare_task_switch sets up locking and calls architecture specific -+ * hooks. -+ */ -+static inline void -+prepare_task_switch(struct rq *rq, struct task_struct *prev, -+ struct task_struct *next) -+{ -+ kcov_prepare_switch(prev); -+ sched_info_switch(rq, prev, next); -+ perf_event_task_sched_out(prev, next); -+ rseq_preempt(prev); -+ fire_sched_out_preempt_notifiers(prev, next); -+ kmap_local_sched_out(); -+ prepare_task(next); -+ prepare_arch_switch(next); -+} -+ -+/** -+ * finish_task_switch - clean up after a task-switch -+ * @rq: runqueue associated with task-switch -+ * @prev: the thread we just switched away from. -+ * -+ * finish_task_switch must be called after the context switch, paired -+ * with a prepare_task_switch call before the context switch. -+ * finish_task_switch will reconcile locking set up by prepare_task_switch, -+ * and do any other architecture-specific cleanup actions. -+ * -+ * Note that we may have delayed dropping an mm in context_switch(). If -+ * so, we finish that here outside of the runqueue lock. (Doing it -+ * with the lock held can cause deadlocks; see schedule() for -+ * details.) -+ * -+ * The context switch have flipped the stack from under us and restored the -+ * local variables which were saved when this task called schedule() in the -+ * past. prev == current is still correct but we need to recalculate this_rq -+ * because prev may have moved to another CPU. -+ */ -+static struct rq *finish_task_switch(struct task_struct *prev) -+ __releases(rq->lock) -+{ -+ struct rq *rq = this_rq(); -+ struct mm_struct *mm = rq->prev_mm; -+ long prev_state; -+ -+ /* -+ * The previous task will have left us with a preempt_count of 2 -+ * because it left us after: -+ * -+ * schedule() -+ * preempt_disable(); // 1 -+ * __schedule() -+ * raw_spin_lock_irq(&rq->lock) // 2 -+ * -+ * Also, see FORK_PREEMPT_COUNT. -+ */ -+ if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET, -+ "corrupted preempt_count: %s/%d/0x%x\n", -+ current->comm, current->pid, preempt_count())) -+ preempt_count_set(FORK_PREEMPT_COUNT); -+ -+ rq->prev_mm = NULL; -+ -+ /* -+ * A task struct has one reference for the use as "current". -+ * If a task dies, then it sets TASK_DEAD in tsk->state and calls -+ * schedule one last time. The schedule call will never return, and -+ * the scheduled task must drop that reference. -+ * -+ * We must observe prev->state before clearing prev->on_cpu (in -+ * finish_task), otherwise a concurrent wakeup can get prev -+ * running on another CPU and we could rave with its RUNNING -> DEAD -+ * transition, resulting in a double drop. -+ */ -+ prev_state = READ_ONCE(prev->__state); -+ vtime_task_switch(prev); -+ perf_event_task_sched_in(prev, current); -+ finish_task(prev); -+ tick_nohz_task_switch(); -+ finish_lock_switch(rq); -+ finish_arch_post_lock_switch(); -+ kcov_finish_switch(current); -+ /* -+ * kmap_local_sched_out() is invoked with rq::lock held and -+ * interrupts disabled. There is no requirement for that, but the -+ * sched out code does not have an interrupt enabled section. -+ * Restoring the maps on sched in does not require interrupts being -+ * disabled either. -+ */ -+ kmap_local_sched_in(); -+ -+ fire_sched_in_preempt_notifiers(current); -+ /* -+ * When switching through a kernel thread, the loop in -+ * membarrier_{private,global}_expedited() may have observed that -+ * kernel thread and not issued an IPI. It is therefore possible to -+ * schedule between user->kernel->user threads without passing though -+ * switch_mm(). Membarrier requires a barrier after storing to -+ * rq->curr, before returning to userspace, so provide them here: -+ * -+ * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly -+ * provided by mmdrop(), -+ * - a sync_core for SYNC_CORE. -+ */ -+ if (mm) { -+ membarrier_mm_sync_core_before_usermode(mm); -+ mmdrop(mm); -+ } -+ if (unlikely(prev_state == TASK_DEAD)) { -+ /* -+ * Remove function-return probe instances associated with this -+ * task and put them back on the free list. -+ */ -+ kprobe_flush_task(prev); -+ -+ /* Task is done with its stack. */ -+ put_task_stack(prev); -+ -+ put_task_struct_rcu_user(prev); -+ } -+ -+ return rq; -+} -+ -+/** -+ * schedule_tail - first thing a freshly forked thread must call. -+ * @prev: the thread we just switched away from. -+ */ -+asmlinkage __visible void schedule_tail(struct task_struct *prev) -+ __releases(rq->lock) -+{ -+ /* -+ * New tasks start with FORK_PREEMPT_COUNT, see there and -+ * finish_task_switch() for details. -+ * -+ * finish_task_switch() will drop rq->lock() and lower preempt_count -+ * and the preempt_enable() will end up enabling preemption (on -+ * PREEMPT_COUNT kernels). -+ */ -+ -+ finish_task_switch(prev); -+ preempt_enable(); -+ -+ if (current->set_child_tid) -+ put_user(task_pid_vnr(current), current->set_child_tid); -+ -+ calculate_sigpending(); -+} -+ -+/* -+ * context_switch - switch to the new MM and the new thread's register state. -+ */ -+static __always_inline struct rq * -+context_switch(struct rq *rq, struct task_struct *prev, -+ struct task_struct *next) -+{ -+ prepare_task_switch(rq, prev, next); -+ -+ /* -+ * For paravirt, this is coupled with an exit in switch_to to -+ * combine the page table reload and the switch backend into -+ * one hypercall. -+ */ -+ arch_start_context_switch(prev); -+ -+ /* -+ * kernel -> kernel lazy + transfer active -+ * user -> kernel lazy + mmgrab() active -+ * -+ * kernel -> user switch + mmdrop() active -+ * user -> user switch -+ */ -+ if (!next->mm) { // to kernel -+ enter_lazy_tlb(prev->active_mm, next); -+ -+ next->active_mm = prev->active_mm; -+ if (prev->mm) // from user -+ mmgrab(prev->active_mm); -+ else -+ prev->active_mm = NULL; -+ } else { // to user -+ membarrier_switch_mm(rq, prev->active_mm, next->mm); -+ /* -+ * sys_membarrier() requires an smp_mb() between setting -+ * rq->curr / membarrier_switch_mm() and returning to userspace. -+ * -+ * The below provides this either through switch_mm(), or in -+ * case 'prev->active_mm == next->mm' through -+ * finish_task_switch()'s mmdrop(). -+ */ -+ switch_mm_irqs_off(prev->active_mm, next->mm, next); -+ -+ if (!prev->mm) { // from kernel -+ /* will mmdrop() in finish_task_switch(). */ -+ rq->prev_mm = prev->active_mm; -+ prev->active_mm = NULL; -+ } -+ } -+ -+ prepare_lock_switch(rq, next); -+ -+ /* Here we just switch the register state and the stack. */ -+ switch_to(prev, next, prev); -+ barrier(); -+ -+ return finish_task_switch(prev); -+} -+ -+/* -+ * nr_running, nr_uninterruptible and nr_context_switches: -+ * -+ * externally visible scheduler statistics: current number of runnable -+ * threads, total number of context switches performed since bootup. -+ */ -+unsigned int nr_running(void) -+{ -+ unsigned int i, sum = 0; -+ -+ for_each_online_cpu(i) -+ sum += cpu_rq(i)->nr_running; -+ -+ return sum; -+} -+ -+/* -+ * Check if only the current task is running on the CPU. -+ * -+ * Caution: this function does not check that the caller has disabled -+ * preemption, thus the result might have a time-of-check-to-time-of-use -+ * race. The caller is responsible to use it correctly, for example: -+ * -+ * - from a non-preemptible section (of course) -+ * -+ * - from a thread that is bound to a single CPU -+ * -+ * - in a loop with very short iterations (e.g. a polling loop) -+ */ -+bool single_task_running(void) -+{ -+ return raw_rq()->nr_running == 1; -+} -+EXPORT_SYMBOL(single_task_running); -+ -+unsigned long long nr_context_switches(void) -+{ -+ int i; -+ unsigned long long sum = 0; -+ -+ for_each_possible_cpu(i) -+ sum += cpu_rq(i)->nr_switches; -+ -+ return sum; -+} -+ -+/* -+ * Consumers of these two interfaces, like for example the cpuidle menu -+ * governor, are using nonsensical data. Preferring shallow idle state selection -+ * for a CPU that has IO-wait which might not even end up running the task when -+ * it does become runnable. -+ */ -+ -+unsigned int nr_iowait_cpu(int cpu) -+{ -+ return atomic_read(&cpu_rq(cpu)->nr_iowait); -+} -+ -+/* -+ * IO-wait accounting, and how it's mostly bollocks (on SMP). -+ * -+ * The idea behind IO-wait account is to account the idle time that we could -+ * have spend running if it were not for IO. That is, if we were to improve the -+ * storage performance, we'd have a proportional reduction in IO-wait time. -+ * -+ * This all works nicely on UP, where, when a task blocks on IO, we account -+ * idle time as IO-wait, because if the storage were faster, it could've been -+ * running and we'd not be idle. -+ * -+ * This has been extended to SMP, by doing the same for each CPU. This however -+ * is broken. -+ * -+ * Imagine for instance the case where two tasks block on one CPU, only the one -+ * CPU will have IO-wait accounted, while the other has regular idle. Even -+ * though, if the storage were faster, both could've ran at the same time, -+ * utilising both CPUs. -+ * -+ * This means, that when looking globally, the current IO-wait accounting on -+ * SMP is a lower bound, by reason of under accounting. -+ * -+ * Worse, since the numbers are provided per CPU, they are sometimes -+ * interpreted per CPU, and that is nonsensical. A blocked task isn't strictly -+ * associated with any one particular CPU, it can wake to another CPU than it -+ * blocked on. This means the per CPU IO-wait number is meaningless. -+ * -+ * Task CPU affinities can make all that even more 'interesting'. -+ */ -+ -+unsigned int nr_iowait(void) -+{ -+ unsigned int i, sum = 0; -+ -+ for_each_possible_cpu(i) -+ sum += nr_iowait_cpu(i); -+ -+ return sum; -+} -+ -+#ifdef CONFIG_SMP -+ -+/* -+ * sched_exec - execve() is a valuable balancing opportunity, because at -+ * this point the task has the smallest effective memory and cache -+ * footprint. -+ */ -+void sched_exec(void) -+{ -+ struct task_struct *p = current; -+ unsigned long flags; -+ int dest_cpu; -+ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ dest_cpu = cpumask_any(p->cpus_ptr); -+ if (dest_cpu == smp_processor_id()) -+ goto unlock; -+ -+ if (likely(cpu_active(dest_cpu))) { -+ struct migration_arg arg = { p, dest_cpu }; -+ -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); -+ return; -+ } -+unlock: -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+} -+ -+#endif -+ -+DEFINE_PER_CPU(struct kernel_stat, kstat); -+DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); -+ -+EXPORT_PER_CPU_SYMBOL(kstat); -+EXPORT_PER_CPU_SYMBOL(kernel_cpustat); -+ -+static inline void update_curr(struct rq *rq, struct task_struct *p) -+{ -+ s64 ns = rq->clock_task - p->last_ran; -+ -+ p->sched_time += ns; -+ cgroup_account_cputime(p, ns); -+ account_group_exec_runtime(p, ns); -+ -+ p->time_slice -= ns; -+ p->last_ran = rq->clock_task; -+} -+ -+/* -+ * Return accounted runtime for the task. -+ * Return separately the current's pending runtime that have not been -+ * accounted yet. -+ */ -+unsigned long long task_sched_runtime(struct task_struct *p) -+{ -+ unsigned long flags; -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ u64 ns; -+ -+#if defined(CONFIG_64BIT) && defined(CONFIG_SMP) -+ /* -+ * 64-bit doesn't need locks to atomically read a 64-bit value. -+ * So we have a optimization chance when the task's delta_exec is 0. -+ * Reading ->on_cpu is racy, but this is ok. -+ * -+ * If we race with it leaving CPU, we'll take a lock. So we're correct. -+ * If we race with it entering CPU, unaccounted time is 0. This is -+ * indistinguishable from the read occurring a few cycles earlier. -+ * If we see ->on_cpu without ->on_rq, the task is leaving, and has -+ * been accounted, so we're correct here as well. -+ */ -+ if (!p->on_cpu || !task_on_rq_queued(p)) -+ return tsk_seruntime(p); -+#endif -+ -+ rq = task_access_lock_irqsave(p, &lock, &flags); -+ /* -+ * Must be ->curr _and_ ->on_rq. If dequeued, we would -+ * project cycles that may never be accounted to this -+ * thread, breaking clock_gettime(). -+ */ -+ if (p == rq->curr && task_on_rq_queued(p)) { -+ update_rq_clock(rq); -+ update_curr(rq, p); -+ } -+ ns = tsk_seruntime(p); -+ task_access_unlock_irqrestore(p, lock, &flags); -+ -+ return ns; -+} -+ -+/* This manages tasks that have run out of timeslice during a scheduler_tick */ -+static inline void scheduler_task_tick(struct rq *rq) -+{ -+ struct task_struct *p = rq->curr; -+ -+ if (is_idle_task(p)) -+ return; -+ -+ update_curr(rq, p); -+ cpufreq_update_util(rq, 0); -+ -+ /* -+ * Tasks have less than RESCHED_NS of time slice left they will be -+ * rescheduled. -+ */ -+ if (p->time_slice >= RESCHED_NS) -+ return; -+ set_tsk_need_resched(p); -+ set_preempt_need_resched(); -+} -+ -+#ifdef CONFIG_SCHED_DEBUG -+static u64 cpu_resched_latency(struct rq *rq) -+{ -+ int latency_warn_ms = READ_ONCE(sysctl_resched_latency_warn_ms); -+ u64 resched_latency, now = rq_clock(rq); -+ static bool warned_once; -+ -+ if (sysctl_resched_latency_warn_once && warned_once) -+ return 0; -+ -+ if (!need_resched() || !latency_warn_ms) -+ return 0; -+ -+ if (system_state == SYSTEM_BOOTING) -+ return 0; -+ -+ if (!rq->last_seen_need_resched_ns) { -+ rq->last_seen_need_resched_ns = now; -+ rq->ticks_without_resched = 0; -+ return 0; -+ } -+ -+ rq->ticks_without_resched++; -+ resched_latency = now - rq->last_seen_need_resched_ns; -+ if (resched_latency <= latency_warn_ms * NSEC_PER_MSEC) -+ return 0; -+ -+ warned_once = true; -+ -+ return resched_latency; -+} -+ -+static int __init setup_resched_latency_warn_ms(char *str) -+{ -+ long val; -+ -+ if ((kstrtol(str, 0, &val))) { -+ pr_warn("Unable to set resched_latency_warn_ms\n"); -+ return 1; -+ } -+ -+ sysctl_resched_latency_warn_ms = val; -+ return 1; -+} -+__setup("resched_latency_warn_ms=", setup_resched_latency_warn_ms); -+#else -+static inline u64 cpu_resched_latency(struct rq *rq) { return 0; } -+#endif /* CONFIG_SCHED_DEBUG */ -+ -+/* -+ * This function gets called by the timer code, with HZ frequency. -+ * We call it with interrupts disabled. -+ */ -+void scheduler_tick(void) -+{ -+ int cpu __maybe_unused = smp_processor_id(); -+ struct rq *rq = cpu_rq(cpu); -+ u64 resched_latency; -+ -+ arch_scale_freq_tick(); -+ sched_clock_tick(); -+ -+ raw_spin_lock(&rq->lock); -+ update_rq_clock(rq); -+ -+ scheduler_task_tick(rq); -+ if (sched_feat(LATENCY_WARN)) -+ resched_latency = cpu_resched_latency(rq); -+ calc_global_load_tick(rq); -+ -+ rq->last_tick = rq->clock; -+ raw_spin_unlock(&rq->lock); -+ -+ if (sched_feat(LATENCY_WARN) && resched_latency) -+ resched_latency_warn(cpu, resched_latency); -+ -+ perf_event_task_tick(); -+} -+ -+#ifdef CONFIG_SCHED_SMT -+static inline int active_load_balance_cpu_stop(void *data) -+{ -+ struct rq *rq = this_rq(); -+ struct task_struct *p = data; -+ cpumask_t tmp; -+ unsigned long flags; -+ -+ local_irq_save(flags); -+ -+ raw_spin_lock(&p->pi_lock); -+ raw_spin_lock(&rq->lock); -+ -+ rq->active_balance = 0; -+ /* _something_ may have changed the task, double check again */ -+ if (task_on_rq_queued(p) && task_rq(p) == rq && -+ cpumask_and(&tmp, p->cpus_ptr, &sched_sg_idle_mask) && -+ !is_migration_disabled(p)) { -+ int cpu = cpu_of(rq); -+ int dcpu = __best_mask_cpu(&tmp, per_cpu(sched_cpu_llc_mask, cpu)); -+ rq = move_queued_task(rq, p, dcpu); -+ } -+ -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock(&p->pi_lock); -+ -+ local_irq_restore(flags); -+ -+ return 0; -+} -+ -+/* sg_balance_trigger - trigger slibing group balance for @cpu */ -+static inline int sg_balance_trigger(const int cpu) -+{ -+ struct rq *rq= cpu_rq(cpu); -+ unsigned long flags; -+ struct task_struct *curr; -+ int res; -+ -+ if (!raw_spin_trylock_irqsave(&rq->lock, flags)) -+ return 0; -+ curr = rq->curr; -+ res = (!is_idle_task(curr)) && (1 == rq->nr_running) &&\ -+ cpumask_intersects(curr->cpus_ptr, &sched_sg_idle_mask) &&\ -+ !is_migration_disabled(curr) && (!rq->active_balance); -+ -+ if (res) -+ rq->active_balance = 1; -+ -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ -+ if (res) -+ stop_one_cpu_nowait(cpu, active_load_balance_cpu_stop, -+ curr, &rq->active_balance_work); -+ return res; -+} -+ -+/* -+ * sg_balance_check - slibing group balance check for run queue @rq -+ */ -+static inline void sg_balance_check(struct rq *rq) -+{ -+ cpumask_t chk; -+ int cpu = cpu_of(rq); -+ -+ /* exit when cpu is offline */ -+ if (unlikely(!rq->online)) -+ return; -+ -+ /* -+ * Only cpu in slibing idle group will do the checking and then -+ * find potential cpus which can migrate the current running task -+ */ -+ if (cpumask_test_cpu(cpu, &sched_sg_idle_mask) && -+ cpumask_andnot(&chk, cpu_online_mask, sched_rq_watermark) && -+ cpumask_andnot(&chk, &chk, &sched_rq_pending_mask)) { -+ int i; -+ -+ for_each_cpu_wrap(i, &chk, cpu) { -+ if (cpumask_subset(cpu_smt_mask(i), &chk) && -+ sg_balance_trigger(i)) -+ return; -+ } -+ } -+} -+#endif /* CONFIG_SCHED_SMT */ -+ -+#ifdef CONFIG_NO_HZ_FULL -+ -+struct tick_work { -+ int cpu; -+ atomic_t state; -+ struct delayed_work work; -+}; -+/* Values for ->state, see diagram below. */ -+#define TICK_SCHED_REMOTE_OFFLINE 0 -+#define TICK_SCHED_REMOTE_OFFLINING 1 -+#define TICK_SCHED_REMOTE_RUNNING 2 -+ -+/* -+ * State diagram for ->state: -+ * -+ * -+ * TICK_SCHED_REMOTE_OFFLINE -+ * | ^ -+ * | | -+ * | | sched_tick_remote() -+ * | | -+ * | | -+ * +--TICK_SCHED_REMOTE_OFFLINING -+ * | ^ -+ * | | -+ * sched_tick_start() | | sched_tick_stop() -+ * | | -+ * V | -+ * TICK_SCHED_REMOTE_RUNNING -+ * -+ * -+ * Other transitions get WARN_ON_ONCE(), except that sched_tick_remote() -+ * and sched_tick_start() are happy to leave the state in RUNNING. -+ */ -+ -+static struct tick_work __percpu *tick_work_cpu; -+ -+static void sched_tick_remote(struct work_struct *work) -+{ -+ struct delayed_work *dwork = to_delayed_work(work); -+ struct tick_work *twork = container_of(dwork, struct tick_work, work); -+ int cpu = twork->cpu; -+ struct rq *rq = cpu_rq(cpu); -+ struct task_struct *curr; -+ unsigned long flags; -+ u64 delta; -+ int os; -+ -+ /* -+ * Handle the tick only if it appears the remote CPU is running in full -+ * dynticks mode. The check is racy by nature, but missing a tick or -+ * having one too much is no big deal because the scheduler tick updates -+ * statistics and checks timeslices in a time-independent way, regardless -+ * of when exactly it is running. -+ */ -+ if (!tick_nohz_tick_stopped_cpu(cpu)) -+ goto out_requeue; -+ -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ curr = rq->curr; -+ if (cpu_is_offline(cpu)) -+ goto out_unlock; -+ -+ update_rq_clock(rq); -+ if (!is_idle_task(curr)) { -+ /* -+ * Make sure the next tick runs within a reasonable -+ * amount of time. -+ */ -+ delta = rq_clock_task(rq) - curr->last_ran; -+ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); -+ } -+ scheduler_task_tick(rq); -+ -+ calc_load_nohz_remote(rq); -+out_unlock: -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ -+out_requeue: -+ /* -+ * Run the remote tick once per second (1Hz). This arbitrary -+ * frequency is large enough to avoid overload but short enough -+ * to keep scheduler internal stats reasonably up to date. But -+ * first update state to reflect hotplug activity if required. -+ */ -+ os = atomic_fetch_add_unless(&twork->state, -1, TICK_SCHED_REMOTE_RUNNING); -+ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_OFFLINE); -+ if (os == TICK_SCHED_REMOTE_RUNNING) -+ queue_delayed_work(system_unbound_wq, dwork, HZ); -+} -+ -+static void sched_tick_start(int cpu) -+{ -+ int os; -+ struct tick_work *twork; -+ -+ if (housekeeping_cpu(cpu, HK_FLAG_TICK)) -+ return; -+ -+ WARN_ON_ONCE(!tick_work_cpu); -+ -+ twork = per_cpu_ptr(tick_work_cpu, cpu); -+ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_RUNNING); -+ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_RUNNING); -+ if (os == TICK_SCHED_REMOTE_OFFLINE) { -+ twork->cpu = cpu; -+ INIT_DELAYED_WORK(&twork->work, sched_tick_remote); -+ queue_delayed_work(system_unbound_wq, &twork->work, HZ); -+ } -+} -+ -+#ifdef CONFIG_HOTPLUG_CPU -+static void sched_tick_stop(int cpu) -+{ -+ struct tick_work *twork; -+ -+ if (housekeeping_cpu(cpu, HK_FLAG_TICK)) -+ return; -+ -+ WARN_ON_ONCE(!tick_work_cpu); -+ -+ twork = per_cpu_ptr(tick_work_cpu, cpu); -+ cancel_delayed_work_sync(&twork->work); -+} -+#endif /* CONFIG_HOTPLUG_CPU */ -+ -+int __init sched_tick_offload_init(void) -+{ -+ tick_work_cpu = alloc_percpu(struct tick_work); -+ BUG_ON(!tick_work_cpu); -+ return 0; -+} -+ -+#else /* !CONFIG_NO_HZ_FULL */ -+static inline void sched_tick_start(int cpu) { } -+static inline void sched_tick_stop(int cpu) { } -+#endif -+ -+#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \ -+ defined(CONFIG_PREEMPT_TRACER)) -+/* -+ * If the value passed in is equal to the current preempt count -+ * then we just disabled preemption. Start timing the latency. -+ */ -+static inline void preempt_latency_start(int val) -+{ -+ if (preempt_count() == val) { -+ unsigned long ip = get_lock_parent_ip(); -+#ifdef CONFIG_DEBUG_PREEMPT -+ current->preempt_disable_ip = ip; -+#endif -+ trace_preempt_off(CALLER_ADDR0, ip); -+ } -+} -+ -+void preempt_count_add(int val) -+{ -+#ifdef CONFIG_DEBUG_PREEMPT -+ /* -+ * Underflow? -+ */ -+ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) -+ return; -+#endif -+ __preempt_count_add(val); -+#ifdef CONFIG_DEBUG_PREEMPT -+ /* -+ * Spinlock count overflowing soon? -+ */ -+ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= -+ PREEMPT_MASK - 10); -+#endif -+ preempt_latency_start(val); -+} -+EXPORT_SYMBOL(preempt_count_add); -+NOKPROBE_SYMBOL(preempt_count_add); -+ -+/* -+ * If the value passed in equals to the current preempt count -+ * then we just enabled preemption. Stop timing the latency. -+ */ -+static inline void preempt_latency_stop(int val) -+{ -+ if (preempt_count() == val) -+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip()); -+} -+ -+void preempt_count_sub(int val) -+{ -+#ifdef CONFIG_DEBUG_PREEMPT -+ /* -+ * Underflow? -+ */ -+ if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) -+ return; -+ /* -+ * Is the spinlock portion underflowing? -+ */ -+ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && -+ !(preempt_count() & PREEMPT_MASK))) -+ return; -+#endif -+ -+ preempt_latency_stop(val); -+ __preempt_count_sub(val); -+} -+EXPORT_SYMBOL(preempt_count_sub); -+NOKPROBE_SYMBOL(preempt_count_sub); -+ -+#else -+static inline void preempt_latency_start(int val) { } -+static inline void preempt_latency_stop(int val) { } -+#endif -+ -+static inline unsigned long get_preempt_disable_ip(struct task_struct *p) -+{ -+#ifdef CONFIG_DEBUG_PREEMPT -+ return p->preempt_disable_ip; -+#else -+ return 0; -+#endif -+} -+ -+/* -+ * Print scheduling while atomic bug: -+ */ -+static noinline void __schedule_bug(struct task_struct *prev) -+{ -+ /* Save this before calling printk(), since that will clobber it */ -+ unsigned long preempt_disable_ip = get_preempt_disable_ip(current); -+ -+ if (oops_in_progress) -+ return; -+ -+ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", -+ prev->comm, prev->pid, preempt_count()); -+ -+ debug_show_held_locks(prev); -+ print_modules(); -+ if (irqs_disabled()) -+ print_irqtrace_events(prev); -+ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT) -+ && in_atomic_preempt_off()) { -+ pr_err("Preemption disabled at:"); -+ print_ip_sym(KERN_ERR, preempt_disable_ip); -+ } -+ if (panic_on_warn) -+ panic("scheduling while atomic\n"); -+ -+ dump_stack(); -+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); -+} -+ -+/* -+ * Various schedule()-time debugging checks and statistics: -+ */ -+static inline void schedule_debug(struct task_struct *prev, bool preempt) -+{ -+#ifdef CONFIG_SCHED_STACK_END_CHECK -+ if (task_stack_end_corrupted(prev)) -+ panic("corrupted stack end detected inside scheduler\n"); -+ -+ if (task_scs_end_corrupted(prev)) -+ panic("corrupted shadow stack detected inside scheduler\n"); -+#endif -+ -+#ifdef CONFIG_DEBUG_ATOMIC_SLEEP -+ if (!preempt && READ_ONCE(prev->__state) && prev->non_block_count) { -+ printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n", -+ prev->comm, prev->pid, prev->non_block_count); -+ dump_stack(); -+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); -+ } -+#endif -+ -+ if (unlikely(in_atomic_preempt_off())) { -+ __schedule_bug(prev); -+ preempt_count_set(PREEMPT_DISABLED); -+ } -+ rcu_sleep_check(); -+ SCHED_WARN_ON(ct_state() == CONTEXT_USER); -+ -+ profile_hit(SCHED_PROFILING, __builtin_return_address(0)); -+ -+ schedstat_inc(this_rq()->sched_count); -+} -+ -+/* -+ * Compile time debug macro -+ * #define ALT_SCHED_DEBUG -+ */ -+ -+#ifdef ALT_SCHED_DEBUG -+void alt_sched_debug(void) -+{ -+ printk(KERN_INFO "sched: pending: 0x%04lx, idle: 0x%04lx, sg_idle: 0x%04lx\n", -+ sched_rq_pending_mask.bits[0], -+ sched_rq_watermark[0].bits[0], -+ sched_sg_idle_mask.bits[0]); -+} -+#else -+inline void alt_sched_debug(void) {} -+#endif -+ -+#ifdef CONFIG_SMP -+ -+#define SCHED_RQ_NR_MIGRATION (32U) -+/* -+ * Migrate pending tasks in @rq to @dest_cpu -+ * Will try to migrate mininal of half of @rq nr_running tasks and -+ * SCHED_RQ_NR_MIGRATION to @dest_cpu -+ */ -+static inline int -+migrate_pending_tasks(struct rq *rq, struct rq *dest_rq, const int dest_cpu) -+{ -+ struct task_struct *p, *skip = rq->curr; -+ int nr_migrated = 0; -+ int nr_tries = min(rq->nr_running / 2, SCHED_RQ_NR_MIGRATION); -+ -+ while (skip != rq->idle && nr_tries && -+ (p = sched_rq_next_task(skip, rq)) != rq->idle) { -+ skip = sched_rq_next_task(p, rq); -+ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) { -+ __SCHED_DEQUEUE_TASK(p, rq, 0, ); -+ set_task_cpu(p, dest_cpu); -+ sched_task_sanity_check(p, dest_rq); -+ __SCHED_ENQUEUE_TASK(p, dest_rq, 0); -+ nr_migrated++; -+ } -+ nr_tries--; -+ } -+ -+ return nr_migrated; -+} -+ -+static inline int take_other_rq_tasks(struct rq *rq, int cpu) -+{ -+ struct cpumask *topo_mask, *end_mask; -+ -+ if (unlikely(!rq->online)) -+ return 0; -+ -+ if (cpumask_empty(&sched_rq_pending_mask)) -+ return 0; -+ -+ topo_mask = per_cpu(sched_cpu_topo_masks, cpu) + 1; -+ end_mask = per_cpu(sched_cpu_topo_end_mask, cpu); -+ do { -+ int i; -+ for_each_cpu_and(i, &sched_rq_pending_mask, topo_mask) { -+ int nr_migrated; -+ struct rq *src_rq; -+ -+ src_rq = cpu_rq(i); -+ if (!do_raw_spin_trylock(&src_rq->lock)) -+ continue; -+ spin_acquire(&src_rq->lock.dep_map, -+ SINGLE_DEPTH_NESTING, 1, _RET_IP_); -+ -+ if ((nr_migrated = migrate_pending_tasks(src_rq, rq, cpu))) { -+ src_rq->nr_running -= nr_migrated; -+ if (src_rq->nr_running < 2) -+ cpumask_clear_cpu(i, &sched_rq_pending_mask); -+ -+ rq->nr_running += nr_migrated; -+ if (rq->nr_running > 1) -+ cpumask_set_cpu(cpu, &sched_rq_pending_mask); -+ -+ update_sched_rq_watermark(rq); -+ cpufreq_update_util(rq, 0); -+ -+ spin_release(&src_rq->lock.dep_map, _RET_IP_); -+ do_raw_spin_unlock(&src_rq->lock); -+ -+ return 1; -+ } -+ -+ spin_release(&src_rq->lock.dep_map, _RET_IP_); -+ do_raw_spin_unlock(&src_rq->lock); -+ } -+ } while (++topo_mask < end_mask); -+ -+ return 0; -+} -+#endif -+ -+/* -+ * Timeslices below RESCHED_NS are considered as good as expired as there's no -+ * point rescheduling when there's so little time left. -+ */ -+static inline void check_curr(struct task_struct *p, struct rq *rq) -+{ -+ if (unlikely(rq->idle == p)) -+ return; -+ -+ update_curr(rq, p); -+ -+ if (p->time_slice < RESCHED_NS) -+ time_slice_expired(p, rq); -+} -+ -+static inline struct task_struct * -+choose_next_task(struct rq *rq, int cpu, struct task_struct *prev) -+{ -+ struct task_struct *next; -+ -+ if (unlikely(rq->skip)) { -+ next = rq_runnable_task(rq); -+ if (next == rq->idle) { -+#ifdef CONFIG_SMP -+ if (!take_other_rq_tasks(rq, cpu)) { -+#endif -+ rq->skip = NULL; -+ schedstat_inc(rq->sched_goidle); -+ return next; -+#ifdef CONFIG_SMP -+ } -+ next = rq_runnable_task(rq); -+#endif -+ } -+ rq->skip = NULL; -+#ifdef CONFIG_HIGH_RES_TIMERS -+ hrtick_start(rq, next->time_slice); -+#endif -+ return next; -+ } -+ -+ next = sched_rq_first_task(rq); -+ if (next == rq->idle) { -+#ifdef CONFIG_SMP -+ if (!take_other_rq_tasks(rq, cpu)) { -+#endif -+ schedstat_inc(rq->sched_goidle); -+ /*printk(KERN_INFO "sched: choose_next_task(%d) idle %px\n", cpu, next);*/ -+ return next; -+#ifdef CONFIG_SMP -+ } -+ next = sched_rq_first_task(rq); -+#endif -+ } -+#ifdef CONFIG_HIGH_RES_TIMERS -+ hrtick_start(rq, next->time_slice); -+#endif -+ /*printk(KERN_INFO "sched: choose_next_task(%d) next %px\n", cpu, -+ * next);*/ -+ return next; -+} -+ -+/* -+ * Constants for the sched_mode argument of __schedule(). -+ * -+ * The mode argument allows RT enabled kernels to differentiate a -+ * preemption from blocking on an 'sleeping' spin/rwlock. Note that -+ * SM_MASK_PREEMPT for !RT has all bits set, which allows the compiler to -+ * optimize the AND operation out and just check for zero. -+ */ -+#define SM_NONE 0x0 -+#define SM_PREEMPT 0x1 -+#define SM_RTLOCK_WAIT 0x2 -+ -+#ifndef CONFIG_PREEMPT_RT -+# define SM_MASK_PREEMPT (~0U) -+#else -+# define SM_MASK_PREEMPT SM_PREEMPT -+#endif -+ -+/* -+ * schedule() is the main scheduler function. -+ * -+ * The main means of driving the scheduler and thus entering this function are: -+ * -+ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. -+ * -+ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return -+ * paths. For example, see arch/x86/entry_64.S. -+ * -+ * To drive preemption between tasks, the scheduler sets the flag in timer -+ * interrupt handler scheduler_tick(). -+ * -+ * 3. Wakeups don't really cause entry into schedule(). They add a -+ * task to the run-queue and that's it. -+ * -+ * Now, if the new task added to the run-queue preempts the current -+ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets -+ * called on the nearest possible occasion: -+ * -+ * - If the kernel is preemptible (CONFIG_PREEMPTION=y): -+ * -+ * - in syscall or exception context, at the next outmost -+ * preempt_enable(). (this might be as soon as the wake_up()'s -+ * spin_unlock()!) -+ * -+ * - in IRQ context, return from interrupt-handler to -+ * preemptible context -+ * -+ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set) -+ * then at the next: -+ * -+ * - cond_resched() call -+ * - explicit schedule() call -+ * - return from syscall or exception to user-space -+ * - return from interrupt-handler to user-space -+ * -+ * WARNING: must be called with preemption disabled! -+ */ -+static void __sched notrace __schedule(unsigned int sched_mode) -+{ -+ struct task_struct *prev, *next; -+ unsigned long *switch_count; -+ unsigned long prev_state; -+ struct rq *rq; -+ int cpu; -+ -+ cpu = smp_processor_id(); -+ rq = cpu_rq(cpu); -+ prev = rq->curr; -+ -+ schedule_debug(prev, !!sched_mode); -+ -+ /* by passing sched_feat(HRTICK) checking which Alt schedule FW doesn't support */ -+ hrtick_clear(rq); -+ -+ local_irq_disable(); -+ rcu_note_context_switch(!!sched_mode); -+ -+ /* -+ * Make sure that signal_pending_state()->signal_pending() below -+ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) -+ * done by the caller to avoid the race with signal_wake_up(): -+ * -+ * __set_current_state(@state) signal_wake_up() -+ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING) -+ * wake_up_state(p, state) -+ * LOCK rq->lock LOCK p->pi_state -+ * smp_mb__after_spinlock() smp_mb__after_spinlock() -+ * if (signal_pending_state()) if (p->state & @state) -+ * -+ * Also, the membarrier system call requires a full memory barrier -+ * after coming from user-space, before storing to rq->curr. -+ */ -+ raw_spin_lock(&rq->lock); -+ smp_mb__after_spinlock(); -+ -+ update_rq_clock(rq); -+ -+ switch_count = &prev->nivcsw; -+ /* -+ * We must load prev->state once (task_struct::state is volatile), such -+ * that: -+ * -+ * - we form a control dependency vs deactivate_task() below. -+ * - ptrace_{,un}freeze_traced() can change ->state underneath us. -+ */ -+ prev_state = READ_ONCE(prev->__state); -+ if (!(sched_mode & SM_MASK_PREEMPT) && prev_state) { -+ if (signal_pending_state(prev_state, prev)) { -+ WRITE_ONCE(prev->__state, TASK_RUNNING); -+ } else { -+ prev->sched_contributes_to_load = -+ (prev_state & TASK_UNINTERRUPTIBLE) && -+ !(prev_state & TASK_NOLOAD) && -+ !(prev->flags & PF_FROZEN); -+ -+ if (prev->sched_contributes_to_load) -+ rq->nr_uninterruptible++; -+ -+ /* -+ * __schedule() ttwu() -+ * prev_state = prev->state; if (p->on_rq && ...) -+ * if (prev_state) goto out; -+ * p->on_rq = 0; smp_acquire__after_ctrl_dep(); -+ * p->state = TASK_WAKING -+ * -+ * Where __schedule() and ttwu() have matching control dependencies. -+ * -+ * After this, schedule() must not care about p->state any more. -+ */ -+ sched_task_deactivate(prev, rq); -+ deactivate_task(prev, rq); -+ -+ if (prev->in_iowait) { -+ atomic_inc(&rq->nr_iowait); -+ delayacct_blkio_start(); -+ } -+ } -+ switch_count = &prev->nvcsw; -+ } -+ -+ check_curr(prev, rq); -+ -+ next = choose_next_task(rq, cpu, prev); -+ clear_tsk_need_resched(prev); -+ clear_preempt_need_resched(); -+#ifdef CONFIG_SCHED_DEBUG -+ rq->last_seen_need_resched_ns = 0; -+#endif -+ -+ if (likely(prev != next)) { -+ next->last_ran = rq->clock_task; -+ rq->last_ts_switch = rq->clock; -+ -+ rq->nr_switches++; -+ /* -+ * RCU users of rcu_dereference(rq->curr) may not see -+ * changes to task_struct made by pick_next_task(). -+ */ -+ RCU_INIT_POINTER(rq->curr, next); -+ /* -+ * The membarrier system call requires each architecture -+ * to have a full memory barrier after updating -+ * rq->curr, before returning to user-space. -+ * -+ * Here are the schemes providing that barrier on the -+ * various architectures: -+ * - mm ? switch_mm() : mmdrop() for x86, s390, sparc, PowerPC. -+ * switch_mm() rely on membarrier_arch_switch_mm() on PowerPC. -+ * - finish_lock_switch() for weakly-ordered -+ * architectures where spin_unlock is a full barrier, -+ * - switch_to() for arm64 (weakly-ordered, spin_unlock -+ * is a RELEASE barrier), -+ */ -+ ++*switch_count; -+ -+ psi_sched_switch(prev, next, !task_on_rq_queued(prev)); -+ -+ trace_sched_switch(sched_mode & SM_MASK_PREEMPT, prev, next); -+ -+ /* Also unlocks the rq: */ -+ rq = context_switch(rq, prev, next); -+ } else { -+ __balance_callbacks(rq); -+ raw_spin_unlock_irq(&rq->lock); -+ } -+ -+#ifdef CONFIG_SCHED_SMT -+ sg_balance_check(rq); -+#endif -+} -+ -+void __noreturn do_task_dead(void) -+{ -+ /* Causes final put_task_struct in finish_task_switch(): */ -+ set_special_state(TASK_DEAD); -+ -+ /* Tell freezer to ignore us: */ -+ current->flags |= PF_NOFREEZE; -+ -+ __schedule(SM_NONE); -+ BUG(); -+ -+ /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ -+ for (;;) -+ cpu_relax(); -+} -+ -+static inline void sched_submit_work(struct task_struct *tsk) -+{ -+ unsigned int task_flags; -+ -+ if (task_is_running(tsk)) -+ return; -+ -+ task_flags = tsk->flags; -+ /* -+ * If a worker went to sleep, notify and ask workqueue whether -+ * it wants to wake up a task to maintain concurrency. -+ * As this function is called inside the schedule() context, -+ * we disable preemption to avoid it calling schedule() again -+ * in the possible wakeup of a kworker and because wq_worker_sleeping() -+ * requires it. -+ */ -+ if (task_flags & (PF_WQ_WORKER | PF_IO_WORKER)) { -+ preempt_disable(); -+ if (task_flags & PF_WQ_WORKER) -+ wq_worker_sleeping(tsk); -+ else -+ io_wq_worker_sleeping(tsk); -+ preempt_enable_no_resched(); -+ } -+ -+ if (tsk_is_pi_blocked(tsk)) -+ return; -+ -+ /* -+ * If we are going to sleep and we have plugged IO queued, -+ * make sure to submit it to avoid deadlocks. -+ */ -+ if (blk_needs_flush_plug(tsk)) -+ blk_schedule_flush_plug(tsk); -+} -+ -+static void sched_update_worker(struct task_struct *tsk) -+{ -+ if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) { -+ if (tsk->flags & PF_WQ_WORKER) -+ wq_worker_running(tsk); -+ else -+ io_wq_worker_running(tsk); -+ } -+} -+ -+asmlinkage __visible void __sched schedule(void) -+{ -+ struct task_struct *tsk = current; -+ -+ sched_submit_work(tsk); -+ do { -+ preempt_disable(); -+ __schedule(SM_NONE); -+ sched_preempt_enable_no_resched(); -+ } while (need_resched()); -+ sched_update_worker(tsk); -+} -+EXPORT_SYMBOL(schedule); -+ -+/* -+ * synchronize_rcu_tasks() makes sure that no task is stuck in preempted -+ * state (have scheduled out non-voluntarily) by making sure that all -+ * tasks have either left the run queue or have gone into user space. -+ * As idle tasks do not do either, they must not ever be preempted -+ * (schedule out non-voluntarily). -+ * -+ * schedule_idle() is similar to schedule_preempt_disable() except that it -+ * never enables preemption because it does not call sched_submit_work(). -+ */ -+void __sched schedule_idle(void) -+{ -+ /* -+ * As this skips calling sched_submit_work(), which the idle task does -+ * regardless because that function is a nop when the task is in a -+ * TASK_RUNNING state, make sure this isn't used someplace that the -+ * current task can be in any other state. Note, idle is always in the -+ * TASK_RUNNING state. -+ */ -+ WARN_ON_ONCE(current->__state); -+ do { -+ __schedule(SM_NONE); -+ } while (need_resched()); -+} -+ -+#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) -+asmlinkage __visible void __sched schedule_user(void) -+{ -+ /* -+ * If we come here after a random call to set_need_resched(), -+ * or we have been woken up remotely but the IPI has not yet arrived, -+ * we haven't yet exited the RCU idle mode. Do it here manually until -+ * we find a better solution. -+ * -+ * NB: There are buggy callers of this function. Ideally we -+ * should warn if prev_state != CONTEXT_USER, but that will trigger -+ * too frequently to make sense yet. -+ */ -+ enum ctx_state prev_state = exception_enter(); -+ schedule(); -+ exception_exit(prev_state); -+} -+#endif -+ -+/** -+ * schedule_preempt_disabled - called with preemption disabled -+ * -+ * Returns with preemption disabled. Note: preempt_count must be 1 -+ */ -+void __sched schedule_preempt_disabled(void) -+{ -+ sched_preempt_enable_no_resched(); -+ schedule(); -+ preempt_disable(); -+} -+ -+#ifdef CONFIG_PREEMPT_RT -+void __sched notrace schedule_rtlock(void) -+{ -+ do { -+ preempt_disable(); -+ __schedule(SM_RTLOCK_WAIT); -+ sched_preempt_enable_no_resched(); -+ } while (need_resched()); -+} -+NOKPROBE_SYMBOL(schedule_rtlock); -+#endif -+ -+static void __sched notrace preempt_schedule_common(void) -+{ -+ do { -+ /* -+ * Because the function tracer can trace preempt_count_sub() -+ * and it also uses preempt_enable/disable_notrace(), if -+ * NEED_RESCHED is set, the preempt_enable_notrace() called -+ * by the function tracer will call this function again and -+ * cause infinite recursion. -+ * -+ * Preemption must be disabled here before the function -+ * tracer can trace. Break up preempt_disable() into two -+ * calls. One to disable preemption without fear of being -+ * traced. The other to still record the preemption latency, -+ * which can also be traced by the function tracer. -+ */ -+ preempt_disable_notrace(); -+ preempt_latency_start(1); -+ __schedule(SM_PREEMPT); -+ preempt_latency_stop(1); -+ preempt_enable_no_resched_notrace(); -+ -+ /* -+ * Check again in case we missed a preemption opportunity -+ * between schedule and now. -+ */ -+ } while (need_resched()); -+} -+ -+#ifdef CONFIG_PREEMPTION -+/* -+ * This is the entry point to schedule() from in-kernel preemption -+ * off of preempt_enable. -+ */ -+asmlinkage __visible void __sched notrace preempt_schedule(void) -+{ -+ /* -+ * If there is a non-zero preempt_count or interrupts are disabled, -+ * we do not want to preempt the current task. Just return.. -+ */ -+ if (likely(!preemptible())) -+ return; -+ -+ preempt_schedule_common(); -+} -+NOKPROBE_SYMBOL(preempt_schedule); -+EXPORT_SYMBOL(preempt_schedule); -+ -+#ifdef CONFIG_PREEMPT_DYNAMIC -+DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func); -+EXPORT_STATIC_CALL_TRAMP(preempt_schedule); -+#endif -+ -+ -+/** -+ * preempt_schedule_notrace - preempt_schedule called by tracing -+ * -+ * The tracing infrastructure uses preempt_enable_notrace to prevent -+ * recursion and tracing preempt enabling caused by the tracing -+ * infrastructure itself. But as tracing can happen in areas coming -+ * from userspace or just about to enter userspace, a preempt enable -+ * can occur before user_exit() is called. This will cause the scheduler -+ * to be called when the system is still in usermode. -+ * -+ * To prevent this, the preempt_enable_notrace will use this function -+ * instead of preempt_schedule() to exit user context if needed before -+ * calling the scheduler. -+ */ -+asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) -+{ -+ enum ctx_state prev_ctx; -+ -+ if (likely(!preemptible())) -+ return; -+ -+ do { -+ /* -+ * Because the function tracer can trace preempt_count_sub() -+ * and it also uses preempt_enable/disable_notrace(), if -+ * NEED_RESCHED is set, the preempt_enable_notrace() called -+ * by the function tracer will call this function again and -+ * cause infinite recursion. -+ * -+ * Preemption must be disabled here before the function -+ * tracer can trace. Break up preempt_disable() into two -+ * calls. One to disable preemption without fear of being -+ * traced. The other to still record the preemption latency, -+ * which can also be traced by the function tracer. -+ */ -+ preempt_disable_notrace(); -+ preempt_latency_start(1); -+ /* -+ * Needs preempt disabled in case user_exit() is traced -+ * and the tracer calls preempt_enable_notrace() causing -+ * an infinite recursion. -+ */ -+ prev_ctx = exception_enter(); -+ __schedule(SM_PREEMPT); -+ exception_exit(prev_ctx); -+ -+ preempt_latency_stop(1); -+ preempt_enable_no_resched_notrace(); -+ } while (need_resched()); -+} -+EXPORT_SYMBOL_GPL(preempt_schedule_notrace); -+ -+#ifdef CONFIG_PREEMPT_DYNAMIC -+DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func); -+EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); -+#endif -+ -+#endif /* CONFIG_PREEMPTION */ -+ -+#ifdef CONFIG_PREEMPT_DYNAMIC -+ -+#include <linux/entry-common.h> -+ -+/* -+ * SC:cond_resched -+ * SC:might_resched -+ * SC:preempt_schedule -+ * SC:preempt_schedule_notrace -+ * SC:irqentry_exit_cond_resched -+ * -+ * -+ * NONE: -+ * cond_resched <- __cond_resched -+ * might_resched <- RET0 -+ * preempt_schedule <- NOP -+ * preempt_schedule_notrace <- NOP -+ * irqentry_exit_cond_resched <- NOP -+ * -+ * VOLUNTARY: -+ * cond_resched <- __cond_resched -+ * might_resched <- __cond_resched -+ * preempt_schedule <- NOP -+ * preempt_schedule_notrace <- NOP -+ * irqentry_exit_cond_resched <- NOP -+ * -+ * FULL: -+ * cond_resched <- RET0 -+ * might_resched <- RET0 -+ * preempt_schedule <- preempt_schedule -+ * preempt_schedule_notrace <- preempt_schedule_notrace -+ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched -+ */ -+ -+enum { -+ preempt_dynamic_none = 0, -+ preempt_dynamic_voluntary, -+ preempt_dynamic_full, -+}; -+ -+int preempt_dynamic_mode = preempt_dynamic_full; -+ -+int sched_dynamic_mode(const char *str) -+{ -+ if (!strcmp(str, "none")) -+ return preempt_dynamic_none; -+ -+ if (!strcmp(str, "voluntary")) -+ return preempt_dynamic_voluntary; -+ -+ if (!strcmp(str, "full")) -+ return preempt_dynamic_full; -+ -+ return -EINVAL; -+} -+ -+void sched_dynamic_update(int mode) -+{ -+ /* -+ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in -+ * the ZERO state, which is invalid. -+ */ -+ static_call_update(cond_resched, __cond_resched); -+ static_call_update(might_resched, __cond_resched); -+ static_call_update(preempt_schedule, __preempt_schedule_func); -+ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); -+ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); -+ -+ switch (mode) { -+ case preempt_dynamic_none: -+ static_call_update(cond_resched, __cond_resched); -+ static_call_update(might_resched, (void *)&__static_call_return0); -+ static_call_update(preempt_schedule, NULL); -+ static_call_update(preempt_schedule_notrace, NULL); -+ static_call_update(irqentry_exit_cond_resched, NULL); -+ pr_info("Dynamic Preempt: none\n"); -+ break; -+ -+ case preempt_dynamic_voluntary: -+ static_call_update(cond_resched, __cond_resched); -+ static_call_update(might_resched, __cond_resched); -+ static_call_update(preempt_schedule, NULL); -+ static_call_update(preempt_schedule_notrace, NULL); -+ static_call_update(irqentry_exit_cond_resched, NULL); -+ pr_info("Dynamic Preempt: voluntary\n"); -+ break; -+ -+ case preempt_dynamic_full: -+ static_call_update(cond_resched, (void *)&__static_call_return0); -+ static_call_update(might_resched, (void *)&__static_call_return0); -+ static_call_update(preempt_schedule, __preempt_schedule_func); -+ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); -+ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); -+ pr_info("Dynamic Preempt: full\n"); -+ break; -+ } -+ -+ preempt_dynamic_mode = mode; -+} -+ -+static int __init setup_preempt_mode(char *str) -+{ -+ int mode = sched_dynamic_mode(str); -+ if (mode < 0) { -+ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str); -+ return 1; -+ } -+ -+ sched_dynamic_update(mode); -+ return 0; -+} -+__setup("preempt=", setup_preempt_mode); -+ -+#endif /* CONFIG_PREEMPT_DYNAMIC */ -+ -+/* -+ * This is the entry point to schedule() from kernel preemption -+ * off of irq context. -+ * Note, that this is called and return with irqs disabled. This will -+ * protect us against recursive calling from irq. -+ */ -+asmlinkage __visible void __sched preempt_schedule_irq(void) -+{ -+ enum ctx_state prev_state; -+ -+ /* Catch callers which need to be fixed */ -+ BUG_ON(preempt_count() || !irqs_disabled()); -+ -+ prev_state = exception_enter(); -+ -+ do { -+ preempt_disable(); -+ local_irq_enable(); -+ __schedule(SM_PREEMPT); -+ local_irq_disable(); -+ sched_preempt_enable_no_resched(); -+ } while (need_resched()); -+ -+ exception_exit(prev_state); -+} -+ -+int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags, -+ void *key) -+{ -+ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC); -+ return try_to_wake_up(curr->private, mode, wake_flags); -+} -+EXPORT_SYMBOL(default_wake_function); -+ -+static inline void check_task_changed(struct task_struct *p, struct rq *rq) -+{ -+ /* Trigger resched if task sched_prio has been modified. */ -+ if (task_on_rq_queued(p) && task_sched_prio_idx(p, rq) != p->sq_idx) { -+ requeue_task(p, rq); -+ check_preempt_curr(rq); -+ } -+} -+ -+static void __setscheduler_prio(struct task_struct *p, int prio) -+{ -+ p->prio = prio; -+} -+ -+#ifdef CONFIG_RT_MUTEXES -+ -+static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) -+{ -+ if (pi_task) -+ prio = min(prio, pi_task->prio); -+ -+ return prio; -+} -+ -+static inline int rt_effective_prio(struct task_struct *p, int prio) -+{ -+ struct task_struct *pi_task = rt_mutex_get_top_task(p); -+ -+ return __rt_effective_prio(pi_task, prio); -+} -+ -+/* -+ * rt_mutex_setprio - set the current priority of a task -+ * @p: task to boost -+ * @pi_task: donor task -+ * -+ * This function changes the 'effective' priority of a task. It does -+ * not touch ->normal_prio like __setscheduler(). -+ * -+ * Used by the rt_mutex code to implement priority inheritance -+ * logic. Call site only calls if the priority of the task changed. -+ */ -+void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) -+{ -+ int prio; -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ -+ /* XXX used to be waiter->prio, not waiter->task->prio */ -+ prio = __rt_effective_prio(pi_task, p->normal_prio); -+ -+ /* -+ * If nothing changed; bail early. -+ */ -+ if (p->pi_top_task == pi_task && prio == p->prio) -+ return; -+ -+ rq = __task_access_lock(p, &lock); -+ /* -+ * Set under pi_lock && rq->lock, such that the value can be used under -+ * either lock. -+ * -+ * Note that there is loads of tricky to make this pointer cache work -+ * right. rt_mutex_slowunlock()+rt_mutex_postunlock() work together to -+ * ensure a task is de-boosted (pi_task is set to NULL) before the -+ * task is allowed to run again (and can exit). This ensures the pointer -+ * points to a blocked task -- which guarantees the task is present. -+ */ -+ p->pi_top_task = pi_task; -+ -+ /* -+ * For FIFO/RR we only need to set prio, if that matches we're done. -+ */ -+ if (prio == p->prio) -+ goto out_unlock; -+ -+ /* -+ * Idle task boosting is a nono in general. There is one -+ * exception, when PREEMPT_RT and NOHZ is active: -+ * -+ * The idle task calls get_next_timer_interrupt() and holds -+ * the timer wheel base->lock on the CPU and another CPU wants -+ * to access the timer (probably to cancel it). We can safely -+ * ignore the boosting request, as the idle CPU runs this code -+ * with interrupts disabled and will complete the lock -+ * protected section without being interrupted. So there is no -+ * real need to boost. -+ */ -+ if (unlikely(p == rq->idle)) { -+ WARN_ON(p != rq->curr); -+ WARN_ON(p->pi_blocked_on); -+ goto out_unlock; -+ } -+ -+ trace_sched_pi_setprio(p, pi_task); -+ -+ __setscheduler_prio(p, prio); -+ -+ check_task_changed(p, rq); -+out_unlock: -+ /* Avoid rq from going away on us: */ -+ preempt_disable(); -+ -+ __balance_callbacks(rq); -+ __task_access_unlock(p, lock); -+ -+ preempt_enable(); -+} -+#else -+static inline int rt_effective_prio(struct task_struct *p, int prio) -+{ -+ return prio; -+} -+#endif -+ -+void set_user_nice(struct task_struct *p, long nice) -+{ -+ unsigned long flags; -+ struct rq *rq; -+ raw_spinlock_t *lock; -+ -+ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) -+ return; -+ /* -+ * We have to be careful, if called from sys_setpriority(), -+ * the task might be in the middle of scheduling on another CPU. -+ */ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ rq = __task_access_lock(p, &lock); -+ -+ p->static_prio = NICE_TO_PRIO(nice); -+ /* -+ * The RT priorities are set via sched_setscheduler(), but we still -+ * allow the 'normal' nice value to be set - but as expected -+ * it won't have any effect on scheduling until the task is -+ * not SCHED_NORMAL/SCHED_BATCH: -+ */ -+ if (task_has_rt_policy(p)) -+ goto out_unlock; -+ -+ p->prio = effective_prio(p); -+ -+ check_task_changed(p, rq); -+out_unlock: -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+} -+EXPORT_SYMBOL(set_user_nice); -+ -+/* -+ * can_nice - check if a task can reduce its nice value -+ * @p: task -+ * @nice: nice value -+ */ -+int can_nice(const struct task_struct *p, const int nice) -+{ -+ /* Convert nice value [19,-20] to rlimit style value [1,40] */ -+ int nice_rlim = nice_to_rlimit(nice); -+ -+ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || -+ capable(CAP_SYS_NICE)); -+} -+ -+#ifdef __ARCH_WANT_SYS_NICE -+ -+/* -+ * sys_nice - change the priority of the current process. -+ * @increment: priority increment -+ * -+ * sys_setpriority is a more generic, but much slower function that -+ * does similar things. -+ */ -+SYSCALL_DEFINE1(nice, int, increment) -+{ -+ long nice, retval; -+ -+ /* -+ * Setpriority might change our priority at the same moment. -+ * We don't have to worry. Conceptually one call occurs first -+ * and we have a single winner. -+ */ -+ -+ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); -+ nice = task_nice(current) + increment; -+ -+ nice = clamp_val(nice, MIN_NICE, MAX_NICE); -+ if (increment < 0 && !can_nice(current, nice)) -+ return -EPERM; -+ -+ retval = security_task_setnice(current, nice); -+ if (retval) -+ return retval; -+ -+ set_user_nice(current, nice); -+ return 0; -+} -+ -+#endif -+ -+/** -+ * task_prio - return the priority value of a given task. -+ * @p: the task in question. -+ * -+ * Return: The priority value as seen by users in /proc. -+ * -+ * sched policy return value kernel prio user prio/nice -+ * -+ * (BMQ)normal, batch, idle[0 ... 53] [100 ... 139] 0/[-20 ... 19]/[-7 ... 7] -+ * (PDS)normal, batch, idle[0 ... 39] 100 0/[-20 ... 19] -+ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99] -+ */ -+int task_prio(const struct task_struct *p) -+{ -+ return (p->prio < MAX_RT_PRIO) ? p->prio - MAX_RT_PRIO : -+ task_sched_prio_normal(p, task_rq(p)); -+} -+ -+/** -+ * idle_cpu - is a given CPU idle currently? -+ * @cpu: the processor in question. -+ * -+ * Return: 1 if the CPU is currently idle. 0 otherwise. -+ */ -+int idle_cpu(int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ if (rq->curr != rq->idle) -+ return 0; -+ -+ if (rq->nr_running) -+ return 0; -+ -+#ifdef CONFIG_SMP -+ if (rq->ttwu_pending) -+ return 0; -+#endif -+ -+ return 1; -+} -+ -+/** -+ * idle_task - return the idle task for a given CPU. -+ * @cpu: the processor in question. -+ * -+ * Return: The idle task for the cpu @cpu. -+ */ -+struct task_struct *idle_task(int cpu) -+{ -+ return cpu_rq(cpu)->idle; -+} -+ -+/** -+ * find_process_by_pid - find a process with a matching PID value. -+ * @pid: the pid in question. -+ * -+ * The task of @pid, if found. %NULL otherwise. -+ */ -+static inline struct task_struct *find_process_by_pid(pid_t pid) -+{ -+ return pid ? find_task_by_vpid(pid) : current; -+} -+ -+/* -+ * sched_setparam() passes in -1 for its policy, to let the functions -+ * it calls know not to change it. -+ */ -+#define SETPARAM_POLICY -1 -+ -+static void __setscheduler_params(struct task_struct *p, -+ const struct sched_attr *attr) -+{ -+ int policy = attr->sched_policy; -+ -+ if (policy == SETPARAM_POLICY) -+ policy = p->policy; -+ -+ p->policy = policy; -+ -+ /* -+ * allow normal nice value to be set, but will not have any -+ * effect on scheduling until the task not SCHED_NORMAL/ -+ * SCHED_BATCH -+ */ -+ p->static_prio = NICE_TO_PRIO(attr->sched_nice); -+ -+ /* -+ * __sched_setscheduler() ensures attr->sched_priority == 0 when -+ * !rt_policy. Always setting this ensures that things like -+ * getparam()/getattr() don't report silly values for !rt tasks. -+ */ -+ p->rt_priority = attr->sched_priority; -+ p->normal_prio = normal_prio(p); -+} -+ -+/* -+ * check the target process has a UID that matches the current process's -+ */ -+static bool check_same_owner(struct task_struct *p) -+{ -+ const struct cred *cred = current_cred(), *pcred; -+ bool match; -+ -+ rcu_read_lock(); -+ pcred = __task_cred(p); -+ match = (uid_eq(cred->euid, pcred->euid) || -+ uid_eq(cred->euid, pcred->uid)); -+ rcu_read_unlock(); -+ return match; -+} -+ -+static int __sched_setscheduler(struct task_struct *p, -+ const struct sched_attr *attr, -+ bool user, bool pi) -+{ -+ const struct sched_attr dl_squash_attr = { -+ .size = sizeof(struct sched_attr), -+ .sched_policy = SCHED_FIFO, -+ .sched_nice = 0, -+ .sched_priority = 99, -+ }; -+ int oldpolicy = -1, policy = attr->sched_policy; -+ int retval, newprio; -+ struct callback_head *head; -+ unsigned long flags; -+ struct rq *rq; -+ int reset_on_fork; -+ raw_spinlock_t *lock; -+ -+ /* The pi code expects interrupts enabled */ -+ BUG_ON(pi && in_interrupt()); -+ -+ /* -+ * Alt schedule FW supports SCHED_DEADLINE by squash it as prio 0 SCHED_FIFO -+ */ -+ if (unlikely(SCHED_DEADLINE == policy)) { -+ attr = &dl_squash_attr; -+ policy = attr->sched_policy; -+ } -+recheck: -+ /* Double check policy once rq lock held */ -+ if (policy < 0) { -+ reset_on_fork = p->sched_reset_on_fork; -+ policy = oldpolicy = p->policy; -+ } else { -+ reset_on_fork = !!(attr->sched_flags & SCHED_RESET_ON_FORK); -+ -+ if (policy > SCHED_IDLE) -+ return -EINVAL; -+ } -+ -+ if (attr->sched_flags & ~(SCHED_FLAG_ALL)) -+ return -EINVAL; -+ -+ /* -+ * Valid priorities for SCHED_FIFO and SCHED_RR are -+ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL and -+ * SCHED_BATCH and SCHED_IDLE is 0. -+ */ -+ if (attr->sched_priority < 0 || -+ (p->mm && attr->sched_priority > MAX_RT_PRIO - 1) || -+ (!p->mm && attr->sched_priority > MAX_RT_PRIO - 1)) -+ return -EINVAL; -+ if ((SCHED_RR == policy || SCHED_FIFO == policy) != -+ (attr->sched_priority != 0)) -+ return -EINVAL; -+ -+ /* -+ * Allow unprivileged RT tasks to decrease priority: -+ */ -+ if (user && !capable(CAP_SYS_NICE)) { -+ if (SCHED_FIFO == policy || SCHED_RR == policy) { -+ unsigned long rlim_rtprio = -+ task_rlimit(p, RLIMIT_RTPRIO); -+ -+ /* Can't set/change the rt policy */ -+ if (policy != p->policy && !rlim_rtprio) -+ return -EPERM; -+ -+ /* Can't increase priority */ -+ if (attr->sched_priority > p->rt_priority && -+ attr->sched_priority > rlim_rtprio) -+ return -EPERM; -+ } -+ -+ /* Can't change other user's priorities */ -+ if (!check_same_owner(p)) -+ return -EPERM; -+ -+ /* Normal users shall not reset the sched_reset_on_fork flag */ -+ if (p->sched_reset_on_fork && !reset_on_fork) -+ return -EPERM; -+ } -+ -+ if (user) { -+ retval = security_task_setscheduler(p); -+ if (retval) -+ return retval; -+ } -+ -+ if (pi) -+ cpuset_read_lock(); -+ -+ /* -+ * Make sure no PI-waiters arrive (or leave) while we are -+ * changing the priority of the task: -+ */ -+ raw_spin_lock_irqsave(&p->pi_lock, flags); -+ -+ /* -+ * To be able to change p->policy safely, task_access_lock() -+ * must be called. -+ * IF use task_access_lock() here: -+ * For the task p which is not running, reading rq->stop is -+ * racy but acceptable as ->stop doesn't change much. -+ * An enhancemnet can be made to read rq->stop saftly. -+ */ -+ rq = __task_access_lock(p, &lock); -+ -+ /* -+ * Changing the policy of the stop threads its a very bad idea -+ */ -+ if (p == rq->stop) { -+ retval = -EINVAL; -+ goto unlock; -+ } -+ -+ /* -+ * If not changing anything there's no need to proceed further: -+ */ -+ if (unlikely(policy == p->policy)) { -+ if (rt_policy(policy) && attr->sched_priority != p->rt_priority) -+ goto change; -+ if (!rt_policy(policy) && -+ NICE_TO_PRIO(attr->sched_nice) != p->static_prio) -+ goto change; -+ -+ p->sched_reset_on_fork = reset_on_fork; -+ retval = 0; -+ goto unlock; -+ } -+change: -+ -+ /* Re-check policy now with rq lock held */ -+ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { -+ policy = oldpolicy = -1; -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ if (pi) -+ cpuset_read_unlock(); -+ goto recheck; -+ } -+ -+ p->sched_reset_on_fork = reset_on_fork; -+ -+ newprio = __normal_prio(policy, attr->sched_priority, NICE_TO_PRIO(attr->sched_nice)); -+ if (pi) { -+ /* -+ * Take priority boosted tasks into account. If the new -+ * effective priority is unchanged, we just store the new -+ * normal parameters and do not touch the scheduler class and -+ * the runqueue. This will be done when the task deboost -+ * itself. -+ */ -+ newprio = rt_effective_prio(p, newprio); -+ } -+ -+ if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { -+ __setscheduler_params(p, attr); -+ __setscheduler_prio(p, newprio); -+ } -+ -+ check_task_changed(p, rq); -+ -+ /* Avoid rq from going away on us: */ -+ preempt_disable(); -+ head = splice_balance_callbacks(rq); -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ -+ if (pi) { -+ cpuset_read_unlock(); -+ rt_mutex_adjust_pi(p); -+ } -+ -+ /* Run balance callbacks after we've adjusted the PI chain: */ -+ balance_callbacks(rq, head); -+ preempt_enable(); -+ -+ return 0; -+ -+unlock: -+ __task_access_unlock(p, lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, flags); -+ if (pi) -+ cpuset_read_unlock(); -+ return retval; -+} -+ -+static int _sched_setscheduler(struct task_struct *p, int policy, -+ const struct sched_param *param, bool check) -+{ -+ struct sched_attr attr = { -+ .sched_policy = policy, -+ .sched_priority = param->sched_priority, -+ .sched_nice = PRIO_TO_NICE(p->static_prio), -+ }; -+ -+ /* Fixup the legacy SCHED_RESET_ON_FORK hack. */ -+ if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) { -+ attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; -+ policy &= ~SCHED_RESET_ON_FORK; -+ attr.sched_policy = policy; -+ } -+ -+ return __sched_setscheduler(p, &attr, check, true); -+} -+ -+/** -+ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. -+ * @p: the task in question. -+ * @policy: new policy. -+ * @param: structure containing the new RT priority. -+ * -+ * Use sched_set_fifo(), read its comment. -+ * -+ * Return: 0 on success. An error code otherwise. -+ * -+ * NOTE that the task may be already dead. -+ */ -+int sched_setscheduler(struct task_struct *p, int policy, -+ const struct sched_param *param) -+{ -+ return _sched_setscheduler(p, policy, param, true); -+} -+ -+int sched_setattr(struct task_struct *p, const struct sched_attr *attr) -+{ -+ return __sched_setscheduler(p, attr, true, true); -+} -+ -+int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr) -+{ -+ return __sched_setscheduler(p, attr, false, true); -+} -+EXPORT_SYMBOL_GPL(sched_setattr_nocheck); -+ -+/** -+ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. -+ * @p: the task in question. -+ * @policy: new policy. -+ * @param: structure containing the new RT priority. -+ * -+ * Just like sched_setscheduler, only don't bother checking if the -+ * current context has permission. For example, this is needed in -+ * stop_machine(): we create temporary high priority worker threads, -+ * but our caller might not have that capability. -+ * -+ * Return: 0 on success. An error code otherwise. -+ */ -+int sched_setscheduler_nocheck(struct task_struct *p, int policy, -+ const struct sched_param *param) -+{ -+ return _sched_setscheduler(p, policy, param, false); -+} -+ -+/* -+ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally -+ * incapable of resource management, which is the one thing an OS really should -+ * be doing. -+ * -+ * This is of course the reason it is limited to privileged users only. -+ * -+ * Worse still; it is fundamentally impossible to compose static priority -+ * workloads. You cannot take two correctly working static prio workloads -+ * and smash them together and still expect them to work. -+ * -+ * For this reason 'all' FIFO tasks the kernel creates are basically at: -+ * -+ * MAX_RT_PRIO / 2 -+ * -+ * The administrator _MUST_ configure the system, the kernel simply doesn't -+ * know enough information to make a sensible choice. -+ */ -+void sched_set_fifo(struct task_struct *p) -+{ -+ struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 }; -+ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); -+} -+EXPORT_SYMBOL_GPL(sched_set_fifo); -+ -+/* -+ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL. -+ */ -+void sched_set_fifo_low(struct task_struct *p) -+{ -+ struct sched_param sp = { .sched_priority = 1 }; -+ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); -+} -+EXPORT_SYMBOL_GPL(sched_set_fifo_low); -+ -+void sched_set_normal(struct task_struct *p, int nice) -+{ -+ struct sched_attr attr = { -+ .sched_policy = SCHED_NORMAL, -+ .sched_nice = nice, -+ }; -+ WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0); -+} -+EXPORT_SYMBOL_GPL(sched_set_normal); -+ -+static int -+do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) -+{ -+ struct sched_param lparam; -+ struct task_struct *p; -+ int retval; -+ -+ if (!param || pid < 0) -+ return -EINVAL; -+ if (copy_from_user(&lparam, param, sizeof(struct sched_param))) -+ return -EFAULT; -+ -+ rcu_read_lock(); -+ retval = -ESRCH; -+ p = find_process_by_pid(pid); -+ if (likely(p)) -+ get_task_struct(p); -+ rcu_read_unlock(); -+ -+ if (likely(p)) { -+ retval = sched_setscheduler(p, policy, &lparam); -+ put_task_struct(p); -+ } -+ -+ return retval; -+} -+ -+/* -+ * Mimics kernel/events/core.c perf_copy_attr(). -+ */ -+static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *attr) -+{ -+ u32 size; -+ int ret; -+ -+ /* Zero the full structure, so that a short copy will be nice: */ -+ memset(attr, 0, sizeof(*attr)); -+ -+ ret = get_user(size, &uattr->size); -+ if (ret) -+ return ret; -+ -+ /* ABI compatibility quirk: */ -+ if (!size) -+ size = SCHED_ATTR_SIZE_VER0; -+ -+ if (size < SCHED_ATTR_SIZE_VER0 || size > PAGE_SIZE) -+ goto err_size; -+ -+ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); -+ if (ret) { -+ if (ret == -E2BIG) -+ goto err_size; -+ return ret; -+ } -+ -+ /* -+ * XXX: Do we want to be lenient like existing syscalls; or do we want -+ * to be strict and return an error on out-of-bounds values? -+ */ -+ attr->sched_nice = clamp(attr->sched_nice, -20, 19); -+ -+ /* sched/core.c uses zero here but we already know ret is zero */ -+ return 0; -+ -+err_size: -+ put_user(sizeof(*attr), &uattr->size); -+ return -E2BIG; -+} -+ -+/** -+ * sys_sched_setscheduler - set/change the scheduler policy and RT priority -+ * @pid: the pid in question. -+ * @policy: new policy. -+ * -+ * Return: 0 on success. An error code otherwise. -+ * @param: structure containing the new RT priority. -+ */ -+SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, struct sched_param __user *, param) -+{ -+ if (policy < 0) -+ return -EINVAL; -+ -+ return do_sched_setscheduler(pid, policy, param); -+} -+ -+/** -+ * sys_sched_setparam - set/change the RT priority of a thread -+ * @pid: the pid in question. -+ * @param: structure containing the new RT priority. -+ * -+ * Return: 0 on success. An error code otherwise. -+ */ -+SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) -+{ -+ return do_sched_setscheduler(pid, SETPARAM_POLICY, param); -+} -+ -+/** -+ * sys_sched_setattr - same as above, but with extended sched_attr -+ * @pid: the pid in question. -+ * @uattr: structure containing the extended parameters. -+ */ -+SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, -+ unsigned int, flags) -+{ -+ struct sched_attr attr; -+ struct task_struct *p; -+ int retval; -+ -+ if (!uattr || pid < 0 || flags) -+ return -EINVAL; -+ -+ retval = sched_copy_attr(uattr, &attr); -+ if (retval) -+ return retval; -+ -+ if ((int)attr.sched_policy < 0) -+ return -EINVAL; -+ -+ rcu_read_lock(); -+ retval = -ESRCH; -+ p = find_process_by_pid(pid); -+ if (likely(p)) -+ get_task_struct(p); -+ rcu_read_unlock(); -+ -+ if (likely(p)) { -+ retval = sched_setattr(p, &attr); -+ put_task_struct(p); -+ } -+ -+ return retval; -+} -+ -+/** -+ * sys_sched_getscheduler - get the policy (scheduling class) of a thread -+ * @pid: the pid in question. -+ * -+ * Return: On success, the policy of the thread. Otherwise, a negative error -+ * code. -+ */ -+SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) -+{ -+ struct task_struct *p; -+ int retval = -EINVAL; -+ -+ if (pid < 0) -+ goto out_nounlock; -+ -+ retval = -ESRCH; -+ rcu_read_lock(); -+ p = find_process_by_pid(pid); -+ if (p) { -+ retval = security_task_getscheduler(p); -+ if (!retval) -+ retval = p->policy; -+ } -+ rcu_read_unlock(); -+ -+out_nounlock: -+ return retval; -+} -+ -+/** -+ * sys_sched_getscheduler - get the RT priority of a thread -+ * @pid: the pid in question. -+ * @param: structure containing the RT priority. -+ * -+ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error -+ * code. -+ */ -+SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) -+{ -+ struct sched_param lp = { .sched_priority = 0 }; -+ struct task_struct *p; -+ int retval = -EINVAL; -+ -+ if (!param || pid < 0) -+ goto out_nounlock; -+ -+ rcu_read_lock(); -+ p = find_process_by_pid(pid); -+ retval = -ESRCH; -+ if (!p) -+ goto out_unlock; -+ -+ retval = security_task_getscheduler(p); -+ if (retval) -+ goto out_unlock; -+ -+ if (task_has_rt_policy(p)) -+ lp.sched_priority = p->rt_priority; -+ rcu_read_unlock(); -+ -+ /* -+ * This one might sleep, we cannot do it with a spinlock held ... -+ */ -+ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; -+ -+out_nounlock: -+ return retval; -+ -+out_unlock: -+ rcu_read_unlock(); -+ return retval; -+} -+ -+/* -+ * Copy the kernel size attribute structure (which might be larger -+ * than what user-space knows about) to user-space. -+ * -+ * Note that all cases are valid: user-space buffer can be larger or -+ * smaller than the kernel-space buffer. The usual case is that both -+ * have the same size. -+ */ -+static int -+sched_attr_copy_to_user(struct sched_attr __user *uattr, -+ struct sched_attr *kattr, -+ unsigned int usize) -+{ -+ unsigned int ksize = sizeof(*kattr); -+ -+ if (!access_ok(uattr, usize)) -+ return -EFAULT; -+ -+ /* -+ * sched_getattr() ABI forwards and backwards compatibility: -+ * -+ * If usize == ksize then we just copy everything to user-space and all is good. -+ * -+ * If usize < ksize then we only copy as much as user-space has space for, -+ * this keeps ABI compatibility as well. We skip the rest. -+ * -+ * If usize > ksize then user-space is using a newer version of the ABI, -+ * which part the kernel doesn't know about. Just ignore it - tooling can -+ * detect the kernel's knowledge of attributes from the attr->size value -+ * which is set to ksize in this case. -+ */ -+ kattr->size = min(usize, ksize); -+ -+ if (copy_to_user(uattr, kattr, kattr->size)) -+ return -EFAULT; -+ -+ return 0; -+} -+ -+/** -+ * sys_sched_getattr - similar to sched_getparam, but with sched_attr -+ * @pid: the pid in question. -+ * @uattr: structure containing the extended parameters. -+ * @usize: sizeof(attr) for fwd/bwd comp. -+ * @flags: for future extension. -+ */ -+SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, -+ unsigned int, usize, unsigned int, flags) -+{ -+ struct sched_attr kattr = { }; -+ struct task_struct *p; -+ int retval; -+ -+ if (!uattr || pid < 0 || usize > PAGE_SIZE || -+ usize < SCHED_ATTR_SIZE_VER0 || flags) -+ return -EINVAL; -+ -+ rcu_read_lock(); -+ p = find_process_by_pid(pid); -+ retval = -ESRCH; -+ if (!p) -+ goto out_unlock; -+ -+ retval = security_task_getscheduler(p); -+ if (retval) -+ goto out_unlock; -+ -+ kattr.sched_policy = p->policy; -+ if (p->sched_reset_on_fork) -+ kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; -+ if (task_has_rt_policy(p)) -+ kattr.sched_priority = p->rt_priority; -+ else -+ kattr.sched_nice = task_nice(p); -+ kattr.sched_flags &= SCHED_FLAG_ALL; -+ -+#ifdef CONFIG_UCLAMP_TASK -+ kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; -+ kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; -+#endif -+ -+ rcu_read_unlock(); -+ -+ return sched_attr_copy_to_user(uattr, &kattr, usize); -+ -+out_unlock: -+ rcu_read_unlock(); -+ return retval; -+} -+ -+static int -+__sched_setaffinity(struct task_struct *p, const struct cpumask *mask) -+{ -+ int retval; -+ cpumask_var_t cpus_allowed, new_mask; -+ -+ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) -+ return -ENOMEM; -+ -+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { -+ retval = -ENOMEM; -+ goto out_free_cpus_allowed; -+ } -+ -+ cpuset_cpus_allowed(p, cpus_allowed); -+ cpumask_and(new_mask, mask, cpus_allowed); -+again: -+ retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK | SCA_USER); -+ if (retval) -+ goto out_free_new_mask; -+ -+ cpuset_cpus_allowed(p, cpus_allowed); -+ if (!cpumask_subset(new_mask, cpus_allowed)) { -+ /* -+ * We must have raced with a concurrent cpuset -+ * update. Just reset the cpus_allowed to the -+ * cpuset's cpus_allowed -+ */ -+ cpumask_copy(new_mask, cpus_allowed); -+ goto again; -+ } -+ -+out_free_new_mask: -+ free_cpumask_var(new_mask); -+out_free_cpus_allowed: -+ free_cpumask_var(cpus_allowed); -+ return retval; -+} -+ -+long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) -+{ -+ struct task_struct *p; -+ int retval; -+ -+ rcu_read_lock(); -+ -+ p = find_process_by_pid(pid); -+ if (!p) { -+ rcu_read_unlock(); -+ return -ESRCH; -+ } -+ -+ /* Prevent p going away */ -+ get_task_struct(p); -+ rcu_read_unlock(); -+ -+ if (p->flags & PF_NO_SETAFFINITY) { -+ retval = -EINVAL; -+ goto out_put_task; -+ } -+ -+ if (!check_same_owner(p)) { -+ rcu_read_lock(); -+ if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { -+ rcu_read_unlock(); -+ retval = -EPERM; -+ goto out_put_task; -+ } -+ rcu_read_unlock(); -+ } -+ -+ retval = security_task_setscheduler(p); -+ if (retval) -+ goto out_put_task; -+ -+ retval = __sched_setaffinity(p, in_mask); -+out_put_task: -+ put_task_struct(p); -+ return retval; -+} -+ -+static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, -+ struct cpumask *new_mask) -+{ -+ if (len < cpumask_size()) -+ cpumask_clear(new_mask); -+ else if (len > cpumask_size()) -+ len = cpumask_size(); -+ -+ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; -+} -+ -+/** -+ * sys_sched_setaffinity - set the CPU affinity of a process -+ * @pid: pid of the process -+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr -+ * @user_mask_ptr: user-space pointer to the new CPU mask -+ * -+ * Return: 0 on success. An error code otherwise. -+ */ -+SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, -+ unsigned long __user *, user_mask_ptr) -+{ -+ cpumask_var_t new_mask; -+ int retval; -+ -+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) -+ return -ENOMEM; -+ -+ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); -+ if (retval == 0) -+ retval = sched_setaffinity(pid, new_mask); -+ free_cpumask_var(new_mask); -+ return retval; -+} -+ -+long sched_getaffinity(pid_t pid, cpumask_t *mask) -+{ -+ struct task_struct *p; -+ raw_spinlock_t *lock; -+ unsigned long flags; -+ int retval; -+ -+ rcu_read_lock(); -+ -+ retval = -ESRCH; -+ p = find_process_by_pid(pid); -+ if (!p) -+ goto out_unlock; -+ -+ retval = security_task_getscheduler(p); -+ if (retval) -+ goto out_unlock; -+ -+ task_access_lock_irqsave(p, &lock, &flags); -+ cpumask_and(mask, &p->cpus_mask, cpu_active_mask); -+ task_access_unlock_irqrestore(p, lock, &flags); -+ -+out_unlock: -+ rcu_read_unlock(); -+ -+ return retval; -+} -+ -+/** -+ * sys_sched_getaffinity - get the CPU affinity of a process -+ * @pid: pid of the process -+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr -+ * @user_mask_ptr: user-space pointer to hold the current CPU mask -+ * -+ * Return: size of CPU mask copied to user_mask_ptr on success. An -+ * error code otherwise. -+ */ -+SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, -+ unsigned long __user *, user_mask_ptr) -+{ -+ int ret; -+ cpumask_var_t mask; -+ -+ if ((len * BITS_PER_BYTE) < nr_cpu_ids) -+ return -EINVAL; -+ if (len & (sizeof(unsigned long)-1)) -+ return -EINVAL; -+ -+ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) -+ return -ENOMEM; -+ -+ ret = sched_getaffinity(pid, mask); -+ if (ret == 0) { -+ unsigned int retlen = min_t(size_t, len, cpumask_size()); -+ -+ if (copy_to_user(user_mask_ptr, mask, retlen)) -+ ret = -EFAULT; -+ else -+ ret = retlen; -+ } -+ free_cpumask_var(mask); -+ -+ return ret; -+} -+ -+static void do_sched_yield(void) -+{ -+ struct rq *rq; -+ struct rq_flags rf; -+ -+ if (!sched_yield_type) -+ return; -+ -+ rq = this_rq_lock_irq(&rf); -+ -+ schedstat_inc(rq->yld_count); -+ -+ if (1 == sched_yield_type) { -+ if (!rt_task(current)) -+ do_sched_yield_type_1(current, rq); -+ } else if (2 == sched_yield_type) { -+ if (rq->nr_running > 1) -+ rq->skip = current; -+ } -+ -+ preempt_disable(); -+ raw_spin_unlock_irq(&rq->lock); -+ sched_preempt_enable_no_resched(); -+ -+ schedule(); -+} -+ -+/** -+ * sys_sched_yield - yield the current processor to other threads. -+ * -+ * This function yields the current CPU to other tasks. If there are no -+ * other threads running on this CPU then this function will return. -+ * -+ * Return: 0. -+ */ -+SYSCALL_DEFINE0(sched_yield) -+{ -+ do_sched_yield(); -+ return 0; -+} -+ -+#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) -+int __sched __cond_resched(void) -+{ -+ if (should_resched(0)) { -+ preempt_schedule_common(); -+ return 1; -+ } -+ /* -+ * In preemptible kernels, ->rcu_read_lock_nesting tells the tick -+ * whether the current CPU is in an RCU read-side critical section, -+ * so the tick can report quiescent states even for CPUs looping -+ * in kernel context. In contrast, in non-preemptible kernels, -+ * RCU readers leave no in-memory hints, which means that CPU-bound -+ * processes executing in kernel context might never report an -+ * RCU quiescent state. Therefore, the following code causes -+ * cond_resched() to report a quiescent state, but only when RCU -+ * is in urgent need of one. -+ */ -+#ifndef CONFIG_PREEMPT_RCU -+ rcu_all_qs(); -+#endif -+ return 0; -+} -+EXPORT_SYMBOL(__cond_resched); -+#endif -+ -+#ifdef CONFIG_PREEMPT_DYNAMIC -+DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched); -+EXPORT_STATIC_CALL_TRAMP(cond_resched); -+ -+DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched); -+EXPORT_STATIC_CALL_TRAMP(might_resched); -+#endif -+ -+/* -+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock, -+ * call schedule, and on return reacquire the lock. -+ * -+ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level -+ * operations here to prevent schedule() from being called twice (once via -+ * spin_unlock(), once by hand). -+ */ -+int __cond_resched_lock(spinlock_t *lock) -+{ -+ int resched = should_resched(PREEMPT_LOCK_OFFSET); -+ int ret = 0; -+ -+ lockdep_assert_held(lock); -+ -+ if (spin_needbreak(lock) || resched) { -+ spin_unlock(lock); -+ if (resched) -+ preempt_schedule_common(); -+ else -+ cpu_relax(); -+ ret = 1; -+ spin_lock(lock); -+ } -+ return ret; -+} -+EXPORT_SYMBOL(__cond_resched_lock); -+ -+int __cond_resched_rwlock_read(rwlock_t *lock) -+{ -+ int resched = should_resched(PREEMPT_LOCK_OFFSET); -+ int ret = 0; -+ -+ lockdep_assert_held_read(lock); -+ -+ if (rwlock_needbreak(lock) || resched) { -+ read_unlock(lock); -+ if (resched) -+ preempt_schedule_common(); -+ else -+ cpu_relax(); -+ ret = 1; -+ read_lock(lock); -+ } -+ return ret; -+} -+EXPORT_SYMBOL(__cond_resched_rwlock_read); -+ -+int __cond_resched_rwlock_write(rwlock_t *lock) -+{ -+ int resched = should_resched(PREEMPT_LOCK_OFFSET); -+ int ret = 0; -+ -+ lockdep_assert_held_write(lock); -+ -+ if (rwlock_needbreak(lock) || resched) { -+ write_unlock(lock); -+ if (resched) -+ preempt_schedule_common(); -+ else -+ cpu_relax(); -+ ret = 1; -+ write_lock(lock); -+ } -+ return ret; -+} -+EXPORT_SYMBOL(__cond_resched_rwlock_write); -+ -+/** -+ * yield - yield the current processor to other threads. -+ * -+ * Do not ever use this function, there's a 99% chance you're doing it wrong. -+ * -+ * The scheduler is at all times free to pick the calling task as the most -+ * eligible task to run, if removing the yield() call from your code breaks -+ * it, it's already broken. -+ * -+ * Typical broken usage is: -+ * -+ * while (!event) -+ * yield(); -+ * -+ * where one assumes that yield() will let 'the other' process run that will -+ * make event true. If the current task is a SCHED_FIFO task that will never -+ * happen. Never use yield() as a progress guarantee!! -+ * -+ * If you want to use yield() to wait for something, use wait_event(). -+ * If you want to use yield() to be 'nice' for others, use cond_resched(). -+ * If you still want to use yield(), do not! -+ */ -+void __sched yield(void) -+{ -+ set_current_state(TASK_RUNNING); -+ do_sched_yield(); -+} -+EXPORT_SYMBOL(yield); -+ -+/** -+ * yield_to - yield the current processor to another thread in -+ * your thread group, or accelerate that thread toward the -+ * processor it's on. -+ * @p: target task -+ * @preempt: whether task preemption is allowed or not -+ * -+ * It's the caller's job to ensure that the target task struct -+ * can't go away on us before we can do any checks. -+ * -+ * In Alt schedule FW, yield_to is not supported. -+ * -+ * Return: -+ * true (>0) if we indeed boosted the target task. -+ * false (0) if we failed to boost the target. -+ * -ESRCH if there's no task to yield to. -+ */ -+int __sched yield_to(struct task_struct *p, bool preempt) -+{ -+ return 0; -+} -+EXPORT_SYMBOL_GPL(yield_to); -+ -+int io_schedule_prepare(void) -+{ -+ int old_iowait = current->in_iowait; -+ -+ current->in_iowait = 1; -+ blk_schedule_flush_plug(current); -+ -+ return old_iowait; -+} -+ -+void io_schedule_finish(int token) -+{ -+ current->in_iowait = token; -+} -+ -+/* -+ * This task is about to go to sleep on IO. Increment rq->nr_iowait so -+ * that process accounting knows that this is a task in IO wait state. -+ * -+ * But don't do that if it is a deliberate, throttling IO wait (this task -+ * has set its backing_dev_info: the queue against which it should throttle) -+ */ -+ -+long __sched io_schedule_timeout(long timeout) -+{ -+ int token; -+ long ret; -+ -+ token = io_schedule_prepare(); -+ ret = schedule_timeout(timeout); -+ io_schedule_finish(token); -+ -+ return ret; -+} -+EXPORT_SYMBOL(io_schedule_timeout); -+ -+void __sched io_schedule(void) -+{ -+ int token; -+ -+ token = io_schedule_prepare(); -+ schedule(); -+ io_schedule_finish(token); -+} -+EXPORT_SYMBOL(io_schedule); -+ -+/** -+ * sys_sched_get_priority_max - return maximum RT priority. -+ * @policy: scheduling class. -+ * -+ * Return: On success, this syscall returns the maximum -+ * rt_priority that can be used by a given scheduling class. -+ * On failure, a negative error code is returned. -+ */ -+SYSCALL_DEFINE1(sched_get_priority_max, int, policy) -+{ -+ int ret = -EINVAL; -+ -+ switch (policy) { -+ case SCHED_FIFO: -+ case SCHED_RR: -+ ret = MAX_RT_PRIO - 1; -+ break; -+ case SCHED_NORMAL: -+ case SCHED_BATCH: -+ case SCHED_IDLE: -+ ret = 0; -+ break; -+ } -+ return ret; -+} -+ -+/** -+ * sys_sched_get_priority_min - return minimum RT priority. -+ * @policy: scheduling class. -+ * -+ * Return: On success, this syscall returns the minimum -+ * rt_priority that can be used by a given scheduling class. -+ * On failure, a negative error code is returned. -+ */ -+SYSCALL_DEFINE1(sched_get_priority_min, int, policy) -+{ -+ int ret = -EINVAL; -+ -+ switch (policy) { -+ case SCHED_FIFO: -+ case SCHED_RR: -+ ret = 1; -+ break; -+ case SCHED_NORMAL: -+ case SCHED_BATCH: -+ case SCHED_IDLE: -+ ret = 0; -+ break; -+ } -+ return ret; -+} -+ -+static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) -+{ -+ struct task_struct *p; -+ int retval; -+ -+ alt_sched_debug(); -+ -+ if (pid < 0) -+ return -EINVAL; -+ -+ retval = -ESRCH; -+ rcu_read_lock(); -+ p = find_process_by_pid(pid); -+ if (!p) -+ goto out_unlock; -+ -+ retval = security_task_getscheduler(p); -+ if (retval) -+ goto out_unlock; -+ rcu_read_unlock(); -+ -+ *t = ns_to_timespec64(sched_timeslice_ns); -+ return 0; -+ -+out_unlock: -+ rcu_read_unlock(); -+ return retval; -+} -+ -+/** -+ * sys_sched_rr_get_interval - return the default timeslice of a process. -+ * @pid: pid of the process. -+ * @interval: userspace pointer to the timeslice value. -+ * -+ * -+ * Return: On success, 0 and the timeslice is in @interval. Otherwise, -+ * an error code. -+ */ -+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, -+ struct __kernel_timespec __user *, interval) -+{ -+ struct timespec64 t; -+ int retval = sched_rr_get_interval(pid, &t); -+ -+ if (retval == 0) -+ retval = put_timespec64(&t, interval); -+ -+ return retval; -+} -+ -+#ifdef CONFIG_COMPAT_32BIT_TIME -+SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid, -+ struct old_timespec32 __user *, interval) -+{ -+ struct timespec64 t; -+ int retval = sched_rr_get_interval(pid, &t); -+ -+ if (retval == 0) -+ retval = put_old_timespec32(&t, interval); -+ return retval; -+} -+#endif -+ -+void sched_show_task(struct task_struct *p) -+{ -+ unsigned long free = 0; -+ int ppid; -+ -+ if (!try_get_task_stack(p)) -+ return; -+ -+ pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p)); -+ -+ if (task_is_running(p)) -+ pr_cont(" running task "); -+#ifdef CONFIG_DEBUG_STACK_USAGE -+ free = stack_not_used(p); -+#endif -+ ppid = 0; -+ rcu_read_lock(); -+ if (pid_alive(p)) -+ ppid = task_pid_nr(rcu_dereference(p->real_parent)); -+ rcu_read_unlock(); -+ pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n", -+ free, task_pid_nr(p), ppid, -+ (unsigned long)task_thread_info(p)->flags); -+ -+ print_worker_info(KERN_INFO, p); -+ print_stop_info(KERN_INFO, p); -+ show_stack(p, NULL, KERN_INFO); -+ put_task_stack(p); -+} -+EXPORT_SYMBOL_GPL(sched_show_task); -+ -+static inline bool -+state_filter_match(unsigned long state_filter, struct task_struct *p) -+{ -+ unsigned int state = READ_ONCE(p->__state); -+ -+ /* no filter, everything matches */ -+ if (!state_filter) -+ return true; -+ -+ /* filter, but doesn't match */ -+ if (!(state & state_filter)) -+ return false; -+ -+ /* -+ * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows -+ * TASK_KILLABLE). -+ */ -+ if (state_filter == TASK_UNINTERRUPTIBLE && state == TASK_IDLE) -+ return false; -+ -+ return true; -+} -+ -+ -+void show_state_filter(unsigned int state_filter) -+{ -+ struct task_struct *g, *p; -+ -+ rcu_read_lock(); -+ for_each_process_thread(g, p) { -+ /* -+ * reset the NMI-timeout, listing all files on a slow -+ * console might take a lot of time: -+ * Also, reset softlockup watchdogs on all CPUs, because -+ * another CPU might be blocked waiting for us to process -+ * an IPI. -+ */ -+ touch_nmi_watchdog(); -+ touch_all_softlockup_watchdogs(); -+ if (state_filter_match(state_filter, p)) -+ sched_show_task(p); -+ } -+ -+#ifdef CONFIG_SCHED_DEBUG -+ /* TODO: Alt schedule FW should support this -+ if (!state_filter) -+ sysrq_sched_debug_show(); -+ */ -+#endif -+ rcu_read_unlock(); -+ /* -+ * Only show locks if all tasks are dumped: -+ */ -+ if (!state_filter) -+ debug_show_all_locks(); -+} -+ -+void dump_cpu_task(int cpu) -+{ -+ pr_info("Task dump for CPU %d:\n", cpu); -+ sched_show_task(cpu_curr(cpu)); -+} -+ -+/** -+ * init_idle - set up an idle thread for a given CPU -+ * @idle: task in question -+ * @cpu: CPU the idle task belongs to -+ * -+ * NOTE: this function does not set the idle thread's NEED_RESCHED -+ * flag, to make booting more robust. -+ */ -+void __init init_idle(struct task_struct *idle, int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ -+ __sched_fork(0, idle); -+ -+ /* -+ * The idle task doesn't need the kthread struct to function, but it -+ * is dressed up as a per-CPU kthread and thus needs to play the part -+ * if we want to avoid special-casing it in code that deals with per-CPU -+ * kthreads. -+ */ -+ set_kthread_struct(idle); -+ -+ raw_spin_lock_irqsave(&idle->pi_lock, flags); -+ raw_spin_lock(&rq->lock); -+ update_rq_clock(rq); -+ -+ idle->last_ran = rq->clock_task; -+ idle->__state = TASK_RUNNING; -+ /* -+ * PF_KTHREAD should already be set at this point; regardless, make it -+ * look like a proper per-CPU kthread. -+ */ -+ idle->flags |= PF_IDLE | PF_KTHREAD | PF_NO_SETAFFINITY; -+ kthread_set_per_cpu(idle, cpu); -+ -+ sched_queue_init_idle(&rq->queue, idle); -+ -+ scs_task_reset(idle); -+ kasan_unpoison_task_stack(idle); -+ -+#ifdef CONFIG_SMP -+ /* -+ * It's possible that init_idle() gets called multiple times on a task, -+ * in that case do_set_cpus_allowed() will not do the right thing. -+ * -+ * And since this is boot we can forgo the serialisation. -+ */ -+ set_cpus_allowed_common(idle, cpumask_of(cpu)); -+#endif -+ -+ /* Silence PROVE_RCU */ -+ rcu_read_lock(); -+ __set_task_cpu(idle, cpu); -+ rcu_read_unlock(); -+ -+ rq->idle = idle; -+ rcu_assign_pointer(rq->curr, idle); -+ idle->on_cpu = 1; -+ -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock_irqrestore(&idle->pi_lock, flags); -+ -+ /* Set the preempt count _outside_ the spinlocks! */ -+ init_idle_preempt_count(idle, cpu); -+ -+ ftrace_graph_init_idle_task(idle, cpu); -+ vtime_init_idle(idle, cpu); -+#ifdef CONFIG_SMP -+ sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); -+#endif -+} -+ -+#ifdef CONFIG_SMP -+ -+int cpuset_cpumask_can_shrink(const struct cpumask __maybe_unused *cur, -+ const struct cpumask __maybe_unused *trial) -+{ -+ return 1; -+} -+ -+int task_can_attach(struct task_struct *p, -+ const struct cpumask *cs_cpus_allowed) -+{ -+ int ret = 0; -+ -+ /* -+ * Kthreads which disallow setaffinity shouldn't be moved -+ * to a new cpuset; we don't want to change their CPU -+ * affinity and isolating such threads by their set of -+ * allowed nodes is unnecessary. Thus, cpusets are not -+ * applicable for such threads. This prevents checking for -+ * success of set_cpus_allowed_ptr() on all attached tasks -+ * before cpus_mask may be changed. -+ */ -+ if (p->flags & PF_NO_SETAFFINITY) -+ ret = -EINVAL; -+ -+ return ret; -+} -+ -+bool sched_smp_initialized __read_mostly; -+ -+#ifdef CONFIG_HOTPLUG_CPU -+/* -+ * Ensures that the idle task is using init_mm right before its CPU goes -+ * offline. -+ */ -+void idle_task_exit(void) -+{ -+ struct mm_struct *mm = current->active_mm; -+ -+ BUG_ON(current != this_rq()->idle); -+ -+ if (mm != &init_mm) { -+ switch_mm(mm, &init_mm, current); -+ finish_arch_post_lock_switch(); -+ } -+ -+ scs_task_reset(current); -+ /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ -+} -+ -+static int __balance_push_cpu_stop(void *arg) -+{ -+ struct task_struct *p = arg; -+ struct rq *rq = this_rq(); -+ struct rq_flags rf; -+ int cpu; -+ -+ raw_spin_lock_irq(&p->pi_lock); -+ rq_lock(rq, &rf); -+ -+ update_rq_clock(rq); -+ -+ if (task_rq(p) == rq && task_on_rq_queued(p)) { -+ cpu = select_fallback_rq(rq->cpu, p); -+ rq = __migrate_task(rq, p, cpu); -+ } -+ -+ rq_unlock(rq, &rf); -+ raw_spin_unlock_irq(&p->pi_lock); -+ -+ put_task_struct(p); -+ -+ return 0; -+} -+ -+static DEFINE_PER_CPU(struct cpu_stop_work, push_work); -+ -+/* -+ * This is enabled below SCHED_AP_ACTIVE; when !cpu_active(), but only -+ * effective when the hotplug motion is down. -+ */ -+static void balance_push(struct rq *rq) -+{ -+ struct task_struct *push_task = rq->curr; -+ -+ lockdep_assert_held(&rq->lock); -+ -+ /* -+ * Ensure the thing is persistent until balance_push_set(.on = false); -+ */ -+ rq->balance_callback = &balance_push_callback; -+ -+ /* -+ * Only active while going offline and when invoked on the outgoing -+ * CPU. -+ */ -+ if (!cpu_dying(rq->cpu) || rq != this_rq()) -+ return; -+ -+ /* -+ * Both the cpu-hotplug and stop task are in this case and are -+ * required to complete the hotplug process. -+ */ -+ if (kthread_is_per_cpu(push_task) || -+ is_migration_disabled(push_task)) { -+ -+ /* -+ * If this is the idle task on the outgoing CPU try to wake -+ * up the hotplug control thread which might wait for the -+ * last task to vanish. The rcuwait_active() check is -+ * accurate here because the waiter is pinned on this CPU -+ * and can't obviously be running in parallel. -+ * -+ * On RT kernels this also has to check whether there are -+ * pinned and scheduled out tasks on the runqueue. They -+ * need to leave the migrate disabled section first. -+ */ -+ if (!rq->nr_running && !rq_has_pinned_tasks(rq) && -+ rcuwait_active(&rq->hotplug_wait)) { -+ raw_spin_unlock(&rq->lock); -+ rcuwait_wake_up(&rq->hotplug_wait); -+ raw_spin_lock(&rq->lock); -+ } -+ return; -+ } -+ -+ get_task_struct(push_task); -+ /* -+ * Temporarily drop rq->lock such that we can wake-up the stop task. -+ * Both preemption and IRQs are still disabled. -+ */ -+ raw_spin_unlock(&rq->lock); -+ stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task, -+ this_cpu_ptr(&push_work)); -+ /* -+ * At this point need_resched() is true and we'll take the loop in -+ * schedule(). The next pick is obviously going to be the stop task -+ * which kthread_is_per_cpu() and will push this task away. -+ */ -+ raw_spin_lock(&rq->lock); -+} -+ -+static void balance_push_set(int cpu, bool on) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ struct rq_flags rf; -+ -+ rq_lock_irqsave(rq, &rf); -+ if (on) { -+ WARN_ON_ONCE(rq->balance_callback); -+ rq->balance_callback = &balance_push_callback; -+ } else if (rq->balance_callback == &balance_push_callback) { -+ rq->balance_callback = NULL; -+ } -+ rq_unlock_irqrestore(rq, &rf); -+} -+ -+/* -+ * Invoked from a CPUs hotplug control thread after the CPU has been marked -+ * inactive. All tasks which are not per CPU kernel threads are either -+ * pushed off this CPU now via balance_push() or placed on a different CPU -+ * during wakeup. Wait until the CPU is quiescent. -+ */ -+static void balance_hotplug_wait(void) -+{ -+ struct rq *rq = this_rq(); -+ -+ rcuwait_wait_event(&rq->hotplug_wait, -+ rq->nr_running == 1 && !rq_has_pinned_tasks(rq), -+ TASK_UNINTERRUPTIBLE); -+} -+ -+#else -+ -+static void balance_push(struct rq *rq) -+{ -+} -+ -+static void balance_push_set(int cpu, bool on) -+{ -+} -+ -+static inline void balance_hotplug_wait(void) -+{ -+} -+#endif /* CONFIG_HOTPLUG_CPU */ -+ -+static void set_rq_offline(struct rq *rq) -+{ -+ if (rq->online) -+ rq->online = false; -+} -+ -+static void set_rq_online(struct rq *rq) -+{ -+ if (!rq->online) -+ rq->online = true; -+} -+ -+/* -+ * used to mark begin/end of suspend/resume: -+ */ -+static int num_cpus_frozen; -+ -+/* -+ * Update cpusets according to cpu_active mask. If cpusets are -+ * disabled, cpuset_update_active_cpus() becomes a simple wrapper -+ * around partition_sched_domains(). -+ * -+ * If we come here as part of a suspend/resume, don't touch cpusets because we -+ * want to restore it back to its original state upon resume anyway. -+ */ -+static void cpuset_cpu_active(void) -+{ -+ if (cpuhp_tasks_frozen) { -+ /* -+ * num_cpus_frozen tracks how many CPUs are involved in suspend -+ * resume sequence. As long as this is not the last online -+ * operation in the resume sequence, just build a single sched -+ * domain, ignoring cpusets. -+ */ -+ partition_sched_domains(1, NULL, NULL); -+ if (--num_cpus_frozen) -+ return; -+ /* -+ * This is the last CPU online operation. So fall through and -+ * restore the original sched domains by considering the -+ * cpuset configurations. -+ */ -+ cpuset_force_rebuild(); -+ } -+ -+ cpuset_update_active_cpus(); -+} -+ -+static int cpuset_cpu_inactive(unsigned int cpu) -+{ -+ if (!cpuhp_tasks_frozen) { -+ cpuset_update_active_cpus(); -+ } else { -+ num_cpus_frozen++; -+ partition_sched_domains(1, NULL, NULL); -+ } -+ return 0; -+} -+ -+int sched_cpu_activate(unsigned int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ -+ /* -+ * Clear the balance_push callback and prepare to schedule -+ * regular tasks. -+ */ -+ balance_push_set(cpu, false); -+ -+#ifdef CONFIG_SCHED_SMT -+ /* -+ * When going up, increment the number of cores with SMT present. -+ */ -+ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) -+ static_branch_inc_cpuslocked(&sched_smt_present); -+#endif -+ set_cpu_active(cpu, true); -+ -+ if (sched_smp_initialized) -+ cpuset_cpu_active(); -+ -+ /* -+ * Put the rq online, if not already. This happens: -+ * -+ * 1) In the early boot process, because we build the real domains -+ * after all cpus have been brought up. -+ * -+ * 2) At runtime, if cpuset_cpu_active() fails to rebuild the -+ * domains. -+ */ -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ set_rq_online(rq); -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ -+ return 0; -+} -+ -+int sched_cpu_deactivate(unsigned int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ int ret; -+ -+ set_cpu_active(cpu, false); -+ -+ /* -+ * From this point forward, this CPU will refuse to run any task that -+ * is not: migrate_disable() or KTHREAD_IS_PER_CPU, and will actively -+ * push those tasks away until this gets cleared, see -+ * sched_cpu_dying(). -+ */ -+ balance_push_set(cpu, true); -+ -+ /* -+ * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU -+ * users of this state to go away such that all new such users will -+ * observe it. -+ * -+ * Specifically, we rely on ttwu to no longer target this CPU, see -+ * ttwu_queue_cond() and is_cpu_allowed(). -+ * -+ * Do sync before park smpboot threads to take care the rcu boost case. -+ */ -+ synchronize_rcu(); -+ -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ update_rq_clock(rq); -+ set_rq_offline(rq); -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ -+#ifdef CONFIG_SCHED_SMT -+ /* -+ * When going down, decrement the number of cores with SMT present. -+ */ -+ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) { -+ static_branch_dec_cpuslocked(&sched_smt_present); -+ if (!static_branch_likely(&sched_smt_present)) -+ cpumask_clear(&sched_sg_idle_mask); -+ } -+#endif -+ -+ if (!sched_smp_initialized) -+ return 0; -+ -+ ret = cpuset_cpu_inactive(cpu); -+ if (ret) { -+ balance_push_set(cpu, false); -+ set_cpu_active(cpu, true); -+ return ret; -+ } -+ -+ return 0; -+} -+ -+static void sched_rq_cpu_starting(unsigned int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ -+ rq->calc_load_update = calc_load_update; -+} -+ -+int sched_cpu_starting(unsigned int cpu) -+{ -+ sched_rq_cpu_starting(cpu); -+ sched_tick_start(cpu); -+ return 0; -+} -+ -+#ifdef CONFIG_HOTPLUG_CPU -+ -+/* -+ * Invoked immediately before the stopper thread is invoked to bring the -+ * CPU down completely. At this point all per CPU kthreads except the -+ * hotplug thread (current) and the stopper thread (inactive) have been -+ * either parked or have been unbound from the outgoing CPU. Ensure that -+ * any of those which might be on the way out are gone. -+ * -+ * If after this point a bound task is being woken on this CPU then the -+ * responsible hotplug callback has failed to do it's job. -+ * sched_cpu_dying() will catch it with the appropriate fireworks. -+ */ -+int sched_cpu_wait_empty(unsigned int cpu) -+{ -+ balance_hotplug_wait(); -+ return 0; -+} -+ -+/* -+ * Since this CPU is going 'away' for a while, fold any nr_active delta we -+ * might have. Called from the CPU stopper task after ensuring that the -+ * stopper is the last running task on the CPU, so nr_active count is -+ * stable. We need to take the teardown thread which is calling this into -+ * account, so we hand in adjust = 1 to the load calculation. -+ * -+ * Also see the comment "Global load-average calculations". -+ */ -+static void calc_load_migrate(struct rq *rq) -+{ -+ long delta = calc_load_fold_active(rq, 1); -+ -+ if (delta) -+ atomic_long_add(delta, &calc_load_tasks); -+} -+ -+static void dump_rq_tasks(struct rq *rq, const char *loglvl) -+{ -+ struct task_struct *g, *p; -+ int cpu = cpu_of(rq); -+ -+ lockdep_assert_held(&rq->lock); -+ -+ printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running); -+ for_each_process_thread(g, p) { -+ if (task_cpu(p) != cpu) -+ continue; -+ -+ if (!task_on_rq_queued(p)) -+ continue; -+ -+ printk("%s\tpid: %d, name: %s\n", loglvl, p->pid, p->comm); -+ } -+} -+ -+int sched_cpu_dying(unsigned int cpu) -+{ -+ struct rq *rq = cpu_rq(cpu); -+ unsigned long flags; -+ -+ /* Handle pending wakeups and then migrate everything off */ -+ sched_tick_stop(cpu); -+ -+ raw_spin_lock_irqsave(&rq->lock, flags); -+ if (rq->nr_running != 1 || rq_has_pinned_tasks(rq)) { -+ WARN(true, "Dying CPU not properly vacated!"); -+ dump_rq_tasks(rq, KERN_WARNING); -+ } -+ raw_spin_unlock_irqrestore(&rq->lock, flags); -+ -+ calc_load_migrate(rq); -+ hrtick_clear(rq); -+ return 0; -+} -+#endif -+ -+#ifdef CONFIG_SMP -+static void sched_init_topology_cpumask_early(void) -+{ -+ int cpu; -+ cpumask_t *tmp; -+ -+ for_each_possible_cpu(cpu) { -+ /* init topo masks */ -+ tmp = per_cpu(sched_cpu_topo_masks, cpu); -+ -+ cpumask_copy(tmp, cpumask_of(cpu)); -+ tmp++; -+ cpumask_copy(tmp, cpu_possible_mask); -+ per_cpu(sched_cpu_llc_mask, cpu) = tmp; -+ per_cpu(sched_cpu_topo_end_mask, cpu) = ++tmp; -+ /*per_cpu(sd_llc_id, cpu) = cpu;*/ -+ } -+} -+ -+#define TOPOLOGY_CPUMASK(name, mask, last)\ -+ if (cpumask_and(topo, topo, mask)) { \ -+ cpumask_copy(topo, mask); \ -+ printk(KERN_INFO "sched: cpu#%02d topo: 0x%08lx - "#name, \ -+ cpu, (topo++)->bits[0]); \ -+ } \ -+ if (!last) \ -+ cpumask_complement(topo, mask) -+ -+static void sched_init_topology_cpumask(void) -+{ -+ int cpu; -+ cpumask_t *topo; -+ -+ for_each_online_cpu(cpu) { -+ /* take chance to reset time slice for idle tasks */ -+ cpu_rq(cpu)->idle->time_slice = sched_timeslice_ns; -+ -+ topo = per_cpu(sched_cpu_topo_masks, cpu) + 1; -+ -+ cpumask_complement(topo, cpumask_of(cpu)); -+#ifdef CONFIG_SCHED_SMT -+ TOPOLOGY_CPUMASK(smt, topology_sibling_cpumask(cpu), false); -+#endif -+ per_cpu(sd_llc_id, cpu) = cpumask_first(cpu_coregroup_mask(cpu)); -+ per_cpu(sched_cpu_llc_mask, cpu) = topo; -+ TOPOLOGY_CPUMASK(coregroup, cpu_coregroup_mask(cpu), false); -+ -+ TOPOLOGY_CPUMASK(core, topology_core_cpumask(cpu), false); -+ -+ TOPOLOGY_CPUMASK(others, cpu_online_mask, true); -+ -+ per_cpu(sched_cpu_topo_end_mask, cpu) = topo; -+ printk(KERN_INFO "sched: cpu#%02d llc_id = %d, llc_mask idx = %d\n", -+ cpu, per_cpu(sd_llc_id, cpu), -+ (int) (per_cpu(sched_cpu_llc_mask, cpu) - -+ per_cpu(sched_cpu_topo_masks, cpu))); -+ } -+} -+#endif -+ -+void __init sched_init_smp(void) -+{ -+ /* Move init over to a non-isolated CPU */ -+ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) -+ BUG(); -+ current->flags &= ~PF_NO_SETAFFINITY; -+ -+ sched_init_topology_cpumask(); -+ -+ sched_smp_initialized = true; -+} -+#else -+void __init sched_init_smp(void) -+{ -+ cpu_rq(0)->idle->time_slice = sched_timeslice_ns; -+} -+#endif /* CONFIG_SMP */ -+ -+int in_sched_functions(unsigned long addr) -+{ -+ return in_lock_functions(addr) || -+ (addr >= (unsigned long)__sched_text_start -+ && addr < (unsigned long)__sched_text_end); -+} -+ -+#ifdef CONFIG_CGROUP_SCHED -+/* task group related information */ -+struct task_group { -+ struct cgroup_subsys_state css; -+ -+ struct rcu_head rcu; -+ struct list_head list; -+ -+ struct task_group *parent; -+ struct list_head siblings; -+ struct list_head children; -+#ifdef CONFIG_FAIR_GROUP_SCHED -+ unsigned long shares; -+#endif -+}; -+ -+/* -+ * Default task group. -+ * Every task in system belongs to this group at bootup. -+ */ -+struct task_group root_task_group; -+LIST_HEAD(task_groups); -+ -+/* Cacheline aligned slab cache for task_group */ -+static struct kmem_cache *task_group_cache __read_mostly; -+#endif /* CONFIG_CGROUP_SCHED */ -+ -+void __init sched_init(void) -+{ -+ int i; -+ struct rq *rq; -+ -+ printk(KERN_INFO ALT_SCHED_VERSION_MSG); -+ -+ wait_bit_init(); -+ -+#ifdef CONFIG_SMP -+ for (i = 0; i < SCHED_BITS; i++) -+ cpumask_copy(sched_rq_watermark + i, cpu_present_mask); -+#endif -+ -+#ifdef CONFIG_CGROUP_SCHED -+ task_group_cache = KMEM_CACHE(task_group, 0); -+ -+ list_add(&root_task_group.list, &task_groups); -+ INIT_LIST_HEAD(&root_task_group.children); -+ INIT_LIST_HEAD(&root_task_group.siblings); -+#endif /* CONFIG_CGROUP_SCHED */ -+ for_each_possible_cpu(i) { -+ rq = cpu_rq(i); -+ -+ sched_queue_init(&rq->queue); -+ rq->watermark = IDLE_TASK_SCHED_PRIO; -+ rq->skip = NULL; -+ -+ raw_spin_lock_init(&rq->lock); -+ rq->nr_running = rq->nr_uninterruptible = 0; -+ rq->calc_load_active = 0; -+ rq->calc_load_update = jiffies + LOAD_FREQ; -+#ifdef CONFIG_SMP -+ rq->online = false; -+ rq->cpu = i; -+ -+#ifdef CONFIG_SCHED_SMT -+ rq->active_balance = 0; -+#endif -+ -+#ifdef CONFIG_NO_HZ_COMMON -+ INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq); -+#endif -+ rq->balance_callback = &balance_push_callback; -+#ifdef CONFIG_HOTPLUG_CPU -+ rcuwait_init(&rq->hotplug_wait); -+#endif -+#endif /* CONFIG_SMP */ -+ rq->nr_switches = 0; -+ -+ hrtick_rq_init(rq); -+ atomic_set(&rq->nr_iowait, 0); -+ } -+#ifdef CONFIG_SMP -+ /* Set rq->online for cpu 0 */ -+ cpu_rq(0)->online = true; -+#endif -+ /* -+ * The boot idle thread does lazy MMU switching as well: -+ */ -+ mmgrab(&init_mm); -+ enter_lazy_tlb(&init_mm, current); -+ -+ /* -+ * Make us the idle thread. Technically, schedule() should not be -+ * called from this thread, however somewhere below it might be, -+ * but because we are the idle thread, we just pick up running again -+ * when this runqueue becomes "idle". -+ */ -+ init_idle(current, smp_processor_id()); -+ -+ calc_load_update = jiffies + LOAD_FREQ; -+ -+#ifdef CONFIG_SMP -+ idle_thread_set_boot_cpu(); -+ balance_push_set(smp_processor_id(), false); -+ -+ sched_init_topology_cpumask_early(); -+#endif /* SMP */ -+ -+ psi_init(); -+} -+ -+#ifdef CONFIG_DEBUG_ATOMIC_SLEEP -+static inline int preempt_count_equals(int preempt_offset) -+{ -+ int nested = preempt_count() + rcu_preempt_depth(); -+ -+ return (nested == preempt_offset); -+} -+ -+void __might_sleep(const char *file, int line, int preempt_offset) -+{ -+ unsigned int state = get_current_state(); -+ /* -+ * Blocking primitives will set (and therefore destroy) current->state, -+ * since we will exit with TASK_RUNNING make sure we enter with it, -+ * otherwise we will destroy state. -+ */ -+ WARN_ONCE(state != TASK_RUNNING && current->task_state_change, -+ "do not call blocking ops when !TASK_RUNNING; " -+ "state=%x set at [<%p>] %pS\n", state, -+ (void *)current->task_state_change, -+ (void *)current->task_state_change); -+ -+ ___might_sleep(file, line, preempt_offset); -+} -+EXPORT_SYMBOL(__might_sleep); -+ -+void ___might_sleep(const char *file, int line, int preempt_offset) -+{ -+ /* Ratelimiting timestamp: */ -+ static unsigned long prev_jiffy; -+ -+ unsigned long preempt_disable_ip; -+ -+ /* WARN_ON_ONCE() by default, no rate limit required: */ -+ rcu_sleep_check(); -+ -+ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && -+ !is_idle_task(current) && !current->non_block_count) || -+ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING || -+ oops_in_progress) -+ return; -+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) -+ return; -+ prev_jiffy = jiffies; -+ -+ /* Save this before calling printk(), since that will clobber it: */ -+ preempt_disable_ip = get_preempt_disable_ip(current); -+ -+ printk(KERN_ERR -+ "BUG: sleeping function called from invalid context at %s:%d\n", -+ file, line); -+ printk(KERN_ERR -+ "in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n", -+ in_atomic(), irqs_disabled(), current->non_block_count, -+ current->pid, current->comm); -+ -+ if (task_stack_end_corrupted(current)) -+ printk(KERN_EMERG "Thread overran stack, or stack corrupted\n"); -+ -+ debug_show_held_locks(current); -+ if (irqs_disabled()) -+ print_irqtrace_events(current); -+#ifdef CONFIG_DEBUG_PREEMPT -+ if (!preempt_count_equals(preempt_offset)) { -+ pr_err("Preemption disabled at:"); -+ print_ip_sym(KERN_ERR, preempt_disable_ip); -+ } -+#endif -+ dump_stack(); -+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); -+} -+EXPORT_SYMBOL(___might_sleep); -+ -+void __cant_sleep(const char *file, int line, int preempt_offset) -+{ -+ static unsigned long prev_jiffy; -+ -+ if (irqs_disabled()) -+ return; -+ -+ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) -+ return; -+ -+ if (preempt_count() > preempt_offset) -+ return; -+ -+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) -+ return; -+ prev_jiffy = jiffies; -+ -+ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line); -+ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", -+ in_atomic(), irqs_disabled(), -+ current->pid, current->comm); -+ -+ debug_show_held_locks(current); -+ dump_stack(); -+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); -+} -+EXPORT_SYMBOL_GPL(__cant_sleep); -+ -+#ifdef CONFIG_SMP -+void __cant_migrate(const char *file, int line) -+{ -+ static unsigned long prev_jiffy; -+ -+ if (irqs_disabled()) -+ return; -+ -+ if (is_migration_disabled(current)) -+ return; -+ -+ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) -+ return; -+ -+ if (preempt_count() > 0) -+ return; -+ -+ if (current->migration_flags & MDF_FORCE_ENABLED) -+ return; -+ -+ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) -+ return; -+ prev_jiffy = jiffies; -+ -+ pr_err("BUG: assuming non migratable context at %s:%d\n", file, line); -+ pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n", -+ in_atomic(), irqs_disabled(), is_migration_disabled(current), -+ current->pid, current->comm); -+ -+ debug_show_held_locks(current); -+ dump_stack(); -+ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); -+} -+EXPORT_SYMBOL_GPL(__cant_migrate); -+#endif -+#endif -+ -+#ifdef CONFIG_MAGIC_SYSRQ -+void normalize_rt_tasks(void) -+{ -+ struct task_struct *g, *p; -+ struct sched_attr attr = { -+ .sched_policy = SCHED_NORMAL, -+ }; -+ -+ read_lock(&tasklist_lock); -+ for_each_process_thread(g, p) { -+ /* -+ * Only normalize user tasks: -+ */ -+ if (p->flags & PF_KTHREAD) -+ continue; -+ -+ if (!rt_task(p)) { -+ /* -+ * Renice negative nice level userspace -+ * tasks back to 0: -+ */ -+ if (task_nice(p) < 0) -+ set_user_nice(p, 0); -+ continue; -+ } -+ -+ __sched_setscheduler(p, &attr, false, false); -+ } -+ read_unlock(&tasklist_lock); -+} -+#endif /* CONFIG_MAGIC_SYSRQ */ -+ -+#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) -+/* -+ * These functions are only useful for the IA64 MCA handling, or kdb. -+ * -+ * They can only be called when the whole system has been -+ * stopped - every CPU needs to be quiescent, and no scheduling -+ * activity can take place. Using them for anything else would -+ * be a serious bug, and as a result, they aren't even visible -+ * under any other configuration. -+ */ -+ -+/** -+ * curr_task - return the current task for a given CPU. -+ * @cpu: the processor in question. -+ * -+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! -+ * -+ * Return: The current task for @cpu. -+ */ -+struct task_struct *curr_task(int cpu) -+{ -+ return cpu_curr(cpu); -+} -+ -+#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ -+ -+#ifdef CONFIG_IA64 -+/** -+ * ia64_set_curr_task - set the current task for a given CPU. -+ * @cpu: the processor in question. -+ * @p: the task pointer to set. -+ * -+ * Description: This function must only be used when non-maskable interrupts -+ * are serviced on a separate stack. It allows the architecture to switch the -+ * notion of the current task on a CPU in a non-blocking manner. This function -+ * must be called with all CPU's synchronised, and interrupts disabled, the -+ * and caller must save the original value of the current task (see -+ * curr_task() above) and restore that value before reenabling interrupts and -+ * re-starting the system. -+ * -+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! -+ */ -+void ia64_set_curr_task(int cpu, struct task_struct *p) -+{ -+ cpu_curr(cpu) = p; -+} -+ -+#endif -+ -+#ifdef CONFIG_CGROUP_SCHED -+static void sched_free_group(struct task_group *tg) -+{ -+ kmem_cache_free(task_group_cache, tg); -+} -+ -+/* allocate runqueue etc for a new task group */ -+struct task_group *sched_create_group(struct task_group *parent) -+{ -+ struct task_group *tg; -+ -+ tg = kmem_cache_alloc(task_group_cache, GFP_KERNEL | __GFP_ZERO); -+ if (!tg) -+ return ERR_PTR(-ENOMEM); -+ -+ return tg; -+} -+ -+void sched_online_group(struct task_group *tg, struct task_group *parent) -+{ -+} -+ -+/* rcu callback to free various structures associated with a task group */ -+static void sched_free_group_rcu(struct rcu_head *rhp) -+{ -+ /* Now it should be safe to free those cfs_rqs */ -+ sched_free_group(container_of(rhp, struct task_group, rcu)); -+} -+ -+void sched_destroy_group(struct task_group *tg) -+{ -+ /* Wait for possible concurrent references to cfs_rqs complete */ -+ call_rcu(&tg->rcu, sched_free_group_rcu); -+} -+ -+void sched_offline_group(struct task_group *tg) -+{ -+} -+ -+static inline struct task_group *css_tg(struct cgroup_subsys_state *css) -+{ -+ return css ? container_of(css, struct task_group, css) : NULL; -+} -+ -+static struct cgroup_subsys_state * -+cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) -+{ -+ struct task_group *parent = css_tg(parent_css); -+ struct task_group *tg; -+ -+ if (!parent) { -+ /* This is early initialization for the top cgroup */ -+ return &root_task_group.css; -+ } -+ -+ tg = sched_create_group(parent); -+ if (IS_ERR(tg)) -+ return ERR_PTR(-ENOMEM); -+ return &tg->css; -+} -+ -+/* Expose task group only after completing cgroup initialization */ -+static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) -+{ -+ struct task_group *tg = css_tg(css); -+ struct task_group *parent = css_tg(css->parent); -+ -+ if (parent) -+ sched_online_group(tg, parent); -+ return 0; -+} -+ -+static void cpu_cgroup_css_released(struct cgroup_subsys_state *css) -+{ -+ struct task_group *tg = css_tg(css); -+ -+ sched_offline_group(tg); -+} -+ -+static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) -+{ -+ struct task_group *tg = css_tg(css); -+ -+ /* -+ * Relies on the RCU grace period between css_released() and this. -+ */ -+ sched_free_group(tg); -+} -+ -+static void cpu_cgroup_fork(struct task_struct *task) -+{ -+} -+ -+static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) -+{ -+ return 0; -+} -+ -+static void cpu_cgroup_attach(struct cgroup_taskset *tset) -+{ -+} -+ -+#ifdef CONFIG_FAIR_GROUP_SCHED -+static DEFINE_MUTEX(shares_mutex); -+ -+int sched_group_set_shares(struct task_group *tg, unsigned long shares) -+{ -+ /* -+ * We can't change the weight of the root cgroup. -+ */ -+ if (&root_task_group == tg) -+ return -EINVAL; -+ -+ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); -+ -+ mutex_lock(&shares_mutex); -+ if (tg->shares == shares) -+ goto done; -+ -+ tg->shares = shares; -+done: -+ mutex_unlock(&shares_mutex); -+ return 0; -+} -+ -+static int cpu_shares_write_u64(struct cgroup_subsys_state *css, -+ struct cftype *cftype, u64 shareval) -+{ -+ if (shareval > scale_load_down(ULONG_MAX)) -+ shareval = MAX_SHARES; -+ return sched_group_set_shares(css_tg(css), scale_load(shareval)); -+} -+ -+static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, -+ struct cftype *cft) -+{ -+ struct task_group *tg = css_tg(css); -+ -+ return (u64) scale_load_down(tg->shares); -+} -+#endif -+ -+static struct cftype cpu_legacy_files[] = { -+#ifdef CONFIG_FAIR_GROUP_SCHED -+ { -+ .name = "shares", -+ .read_u64 = cpu_shares_read_u64, -+ .write_u64 = cpu_shares_write_u64, -+ }, -+#endif -+ { } /* Terminate */ -+}; -+ -+ -+static struct cftype cpu_files[] = { -+ { } /* terminate */ -+}; -+ -+static int cpu_extra_stat_show(struct seq_file *sf, -+ struct cgroup_subsys_state *css) -+{ -+ return 0; -+} -+ -+struct cgroup_subsys cpu_cgrp_subsys = { -+ .css_alloc = cpu_cgroup_css_alloc, -+ .css_online = cpu_cgroup_css_online, -+ .css_released = cpu_cgroup_css_released, -+ .css_free = cpu_cgroup_css_free, -+ .css_extra_stat_show = cpu_extra_stat_show, -+ .fork = cpu_cgroup_fork, -+ .can_attach = cpu_cgroup_can_attach, -+ .attach = cpu_cgroup_attach, -+ .legacy_cftypes = cpu_files, -+ .legacy_cftypes = cpu_legacy_files, -+ .dfl_cftypes = cpu_files, -+ .early_init = true, -+ .threaded = true, -+}; -+#endif /* CONFIG_CGROUP_SCHED */ -+ -+#undef CREATE_TRACE_POINTS -diff --git a/kernel/sched/alt_debug.c b/kernel/sched/alt_debug.c -new file mode 100644 -index 000000000000..1212a031700e ---- /dev/null -+++ b/kernel/sched/alt_debug.c -@@ -0,0 +1,31 @@ -+/* -+ * kernel/sched/alt_debug.c -+ * -+ * Print the alt scheduler debugging details -+ * -+ * Author: Alfred Chen -+ * Date : 2020 -+ */ -+#include "sched.h" -+ -+/* -+ * This allows printing both to /proc/sched_debug and -+ * to the console -+ */ -+#define SEQ_printf(m, x...) \ -+ do { \ -+ if (m) \ -+ seq_printf(m, x); \ -+ else \ -+ pr_cont(x); \ -+ } while (0) -+ -+void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, -+ struct seq_file *m) -+{ -+ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns), -+ get_nr_threads(p)); -+} -+ -+void proc_sched_set_task(struct task_struct *p) -+{} -diff --git a/kernel/sched/alt_sched.h b/kernel/sched/alt_sched.h -new file mode 100644 -index 000000000000..289058a09bd5 ---- /dev/null -+++ b/kernel/sched/alt_sched.h -@@ -0,0 +1,666 @@ -+#ifndef ALT_SCHED_H -+#define ALT_SCHED_H -+ -+#include <linux/sched.h> -+ -+#include <linux/sched/clock.h> -+#include <linux/sched/cpufreq.h> -+#include <linux/sched/cputime.h> -+#include <linux/sched/debug.h> -+#include <linux/sched/init.h> -+#include <linux/sched/isolation.h> -+#include <linux/sched/loadavg.h> -+#include <linux/sched/mm.h> -+#include <linux/sched/nohz.h> -+#include <linux/sched/signal.h> -+#include <linux/sched/stat.h> -+#include <linux/sched/sysctl.h> -+#include <linux/sched/task.h> -+#include <linux/sched/topology.h> -+#include <linux/sched/wake_q.h> -+ -+#include <uapi/linux/sched/types.h> -+ -+#include <linux/cgroup.h> -+#include <linux/cpufreq.h> -+#include <linux/cpuidle.h> -+#include <linux/cpuset.h> -+#include <linux/ctype.h> -+#include <linux/debugfs.h> -+#include <linux/kthread.h> -+#include <linux/livepatch.h> -+#include <linux/membarrier.h> -+#include <linux/proc_fs.h> -+#include <linux/psi.h> -+#include <linux/slab.h> -+#include <linux/stop_machine.h> -+#include <linux/suspend.h> -+#include <linux/swait.h> -+#include <linux/syscalls.h> -+#include <linux/tsacct_kern.h> -+ -+#include <asm/tlb.h> -+ -+#ifdef CONFIG_PARAVIRT -+# include <asm/paravirt.h> -+#endif -+ -+#include "cpupri.h" -+ -+#include <trace/events/sched.h> -+ -+#ifdef CONFIG_SCHED_BMQ -+/* bits: -+ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */ -+#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + MAX_PRIORITY_ADJ + 1) -+#endif -+ -+#ifdef CONFIG_SCHED_PDS -+/* bits: RT(0-99), reserved(100-127), NORMAL_PRIO_NUM, cpu idle task */ -+#define SCHED_BITS (MIN_NORMAL_PRIO + NORMAL_PRIO_NUM + 1) -+#endif /* CONFIG_SCHED_PDS */ -+ -+#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1) -+ -+#ifdef CONFIG_SCHED_DEBUG -+# define SCHED_WARN_ON(x) WARN_ONCE(x, #x) -+extern void resched_latency_warn(int cpu, u64 latency); -+#else -+# define SCHED_WARN_ON(x) ({ (void)(x), 0; }) -+static inline void resched_latency_warn(int cpu, u64 latency) {} -+#endif -+ -+/* -+ * Increase resolution of nice-level calculations for 64-bit architectures. -+ * The extra resolution improves shares distribution and load balancing of -+ * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup -+ * hierarchies, especially on larger systems. This is not a user-visible change -+ * and does not change the user-interface for setting shares/weights. -+ * -+ * We increase resolution only if we have enough bits to allow this increased -+ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit -+ * are pretty high and the returns do not justify the increased costs. -+ * -+ * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to -+ * increase coverage and consistency always enable it on 64-bit platforms. -+ */ -+#ifdef CONFIG_64BIT -+# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) -+# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) -+# define scale_load_down(w) \ -+({ \ -+ unsigned long __w = (w); \ -+ if (__w) \ -+ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ -+ __w; \ -+}) -+#else -+# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) -+# define scale_load(w) (w) -+# define scale_load_down(w) (w) -+#endif -+ -+#ifdef CONFIG_FAIR_GROUP_SCHED -+#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD -+ -+/* -+ * A weight of 0 or 1 can cause arithmetics problems. -+ * A weight of a cfs_rq is the sum of weights of which entities -+ * are queued on this cfs_rq, so a weight of a entity should not be -+ * too large, so as the shares value of a task group. -+ * (The default weight is 1024 - so there's no practical -+ * limitation from this.) -+ */ -+#define MIN_SHARES (1UL << 1) -+#define MAX_SHARES (1UL << 18) -+#endif -+ -+/* task_struct::on_rq states: */ -+#define TASK_ON_RQ_QUEUED 1 -+#define TASK_ON_RQ_MIGRATING 2 -+ -+static inline int task_on_rq_queued(struct task_struct *p) -+{ -+ return p->on_rq == TASK_ON_RQ_QUEUED; -+} -+ -+static inline int task_on_rq_migrating(struct task_struct *p) -+{ -+ return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; -+} -+ -+/* -+ * wake flags -+ */ -+#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ -+#define WF_FORK 0x02 /* child wakeup after fork */ -+#define WF_MIGRATED 0x04 /* internal use, task got migrated */ -+#define WF_ON_CPU 0x08 /* Wakee is on_rq */ -+ -+#define SCHED_QUEUE_BITS (SCHED_BITS - 1) -+ -+struct sched_queue { -+ DECLARE_BITMAP(bitmap, SCHED_QUEUE_BITS); -+ struct list_head heads[SCHED_BITS]; -+}; -+ -+/* -+ * This is the main, per-CPU runqueue data structure. -+ * This data should only be modified by the local cpu. -+ */ -+struct rq { -+ /* runqueue lock: */ -+ raw_spinlock_t lock; -+ -+ struct task_struct __rcu *curr; -+ struct task_struct *idle, *stop, *skip; -+ struct mm_struct *prev_mm; -+ -+ struct sched_queue queue; -+#ifdef CONFIG_SCHED_PDS -+ u64 time_edge; -+#endif -+ unsigned long watermark; -+ -+ /* switch count */ -+ u64 nr_switches; -+ -+ atomic_t nr_iowait; -+ -+#ifdef CONFIG_SCHED_DEBUG -+ u64 last_seen_need_resched_ns; -+ int ticks_without_resched; -+#endif -+ -+#ifdef CONFIG_MEMBARRIER -+ int membarrier_state; -+#endif -+ -+#ifdef CONFIG_SMP -+ int cpu; /* cpu of this runqueue */ -+ bool online; -+ -+ unsigned int ttwu_pending; -+ unsigned char nohz_idle_balance; -+ unsigned char idle_balance; -+ -+#ifdef CONFIG_HAVE_SCHED_AVG_IRQ -+ struct sched_avg avg_irq; -+#endif -+ -+#ifdef CONFIG_SCHED_SMT -+ int active_balance; -+ struct cpu_stop_work active_balance_work; -+#endif -+ struct callback_head *balance_callback; -+#ifdef CONFIG_HOTPLUG_CPU -+ struct rcuwait hotplug_wait; -+#endif -+ unsigned int nr_pinned; -+ -+#endif /* CONFIG_SMP */ -+#ifdef CONFIG_IRQ_TIME_ACCOUNTING -+ u64 prev_irq_time; -+#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ -+#ifdef CONFIG_PARAVIRT -+ u64 prev_steal_time; -+#endif /* CONFIG_PARAVIRT */ -+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING -+ u64 prev_steal_time_rq; -+#endif /* CONFIG_PARAVIRT_TIME_ACCOUNTING */ -+ -+ /* For genenal cpu load util */ -+ s32 load_history; -+ u64 load_block; -+ u64 load_stamp; -+ -+ /* calc_load related fields */ -+ unsigned long calc_load_update; -+ long calc_load_active; -+ -+ u64 clock, last_tick; -+ u64 last_ts_switch; -+ u64 clock_task; -+ -+ unsigned int nr_running; -+ unsigned long nr_uninterruptible; -+ -+#ifdef CONFIG_SCHED_HRTICK -+#ifdef CONFIG_SMP -+ call_single_data_t hrtick_csd; -+#endif -+ struct hrtimer hrtick_timer; -+ ktime_t hrtick_time; -+#endif -+ -+#ifdef CONFIG_SCHEDSTATS -+ -+ /* latency stats */ -+ struct sched_info rq_sched_info; -+ unsigned long long rq_cpu_time; -+ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ -+ -+ /* sys_sched_yield() stats */ -+ unsigned int yld_count; -+ -+ /* schedule() stats */ -+ unsigned int sched_switch; -+ unsigned int sched_count; -+ unsigned int sched_goidle; -+ -+ /* try_to_wake_up() stats */ -+ unsigned int ttwu_count; -+ unsigned int ttwu_local; -+#endif /* CONFIG_SCHEDSTATS */ -+ -+#ifdef CONFIG_CPU_IDLE -+ /* Must be inspected within a rcu lock section */ -+ struct cpuidle_state *idle_state; -+#endif -+ -+#ifdef CONFIG_NO_HZ_COMMON -+#ifdef CONFIG_SMP -+ call_single_data_t nohz_csd; -+#endif -+ atomic_t nohz_flags; -+#endif /* CONFIG_NO_HZ_COMMON */ -+}; -+ -+extern unsigned long rq_load_util(struct rq *rq, unsigned long max); -+ -+extern unsigned long calc_load_update; -+extern atomic_long_t calc_load_tasks; -+ -+extern void calc_global_load_tick(struct rq *this_rq); -+extern long calc_load_fold_active(struct rq *this_rq, long adjust); -+ -+DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -+#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) -+#define this_rq() this_cpu_ptr(&runqueues) -+#define task_rq(p) cpu_rq(task_cpu(p)) -+#define cpu_curr(cpu) (cpu_rq(cpu)->curr) -+#define raw_rq() raw_cpu_ptr(&runqueues) -+ -+#ifdef CONFIG_SMP -+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) -+void register_sched_domain_sysctl(void); -+void unregister_sched_domain_sysctl(void); -+#else -+static inline void register_sched_domain_sysctl(void) -+{ -+} -+static inline void unregister_sched_domain_sysctl(void) -+{ -+} -+#endif -+ -+extern bool sched_smp_initialized; -+ -+enum { -+ ITSELF_LEVEL_SPACE_HOLDER, -+#ifdef CONFIG_SCHED_SMT -+ SMT_LEVEL_SPACE_HOLDER, -+#endif -+ COREGROUP_LEVEL_SPACE_HOLDER, -+ CORE_LEVEL_SPACE_HOLDER, -+ OTHER_LEVEL_SPACE_HOLDER, -+ NR_CPU_AFFINITY_LEVELS -+}; -+ -+DECLARE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); -+DECLARE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); -+ -+static inline int -+__best_mask_cpu(const cpumask_t *cpumask, const cpumask_t *mask) -+{ -+ int cpu; -+ -+ while ((cpu = cpumask_any_and(cpumask, mask)) >= nr_cpu_ids) -+ mask++; -+ -+ return cpu; -+} -+ -+static inline int best_mask_cpu(int cpu, const cpumask_t *mask) -+{ -+ return __best_mask_cpu(mask, per_cpu(sched_cpu_topo_masks, cpu)); -+} -+ -+extern void flush_smp_call_function_from_idle(void); -+ -+#else /* !CONFIG_SMP */ -+static inline void flush_smp_call_function_from_idle(void) { } -+#endif -+ -+#ifndef arch_scale_freq_tick -+static __always_inline -+void arch_scale_freq_tick(void) -+{ -+} -+#endif -+ -+#ifndef arch_scale_freq_capacity -+static __always_inline -+unsigned long arch_scale_freq_capacity(int cpu) -+{ -+ return SCHED_CAPACITY_SCALE; -+} -+#endif -+ -+static inline u64 __rq_clock_broken(struct rq *rq) -+{ -+ return READ_ONCE(rq->clock); -+} -+ -+static inline u64 rq_clock(struct rq *rq) -+{ -+ /* -+ * Relax lockdep_assert_held() checking as in VRQ, call to -+ * sched_info_xxxx() may not held rq->lock -+ * lockdep_assert_held(&rq->lock); -+ */ -+ return rq->clock; -+} -+ -+static inline u64 rq_clock_task(struct rq *rq) -+{ -+ /* -+ * Relax lockdep_assert_held() checking as in VRQ, call to -+ * sched_info_xxxx() may not held rq->lock -+ * lockdep_assert_held(&rq->lock); -+ */ -+ return rq->clock_task; -+} -+ -+/* -+ * {de,en}queue flags: -+ * -+ * DEQUEUE_SLEEP - task is no longer runnable -+ * ENQUEUE_WAKEUP - task just became runnable -+ * -+ */ -+ -+#define DEQUEUE_SLEEP 0x01 -+ -+#define ENQUEUE_WAKEUP 0x01 -+ -+ -+/* -+ * Below are scheduler API which using in other kernel code -+ * It use the dummy rq_flags -+ * ToDo : BMQ need to support these APIs for compatibility with mainline -+ * scheduler code. -+ */ -+struct rq_flags { -+ unsigned long flags; -+}; -+ -+struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) -+ __acquires(rq->lock); -+ -+struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) -+ __acquires(p->pi_lock) -+ __acquires(rq->lock); -+ -+static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) -+ __releases(rq->lock) -+{ -+ raw_spin_unlock(&rq->lock); -+} -+ -+static inline void -+task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) -+ __releases(rq->lock) -+ __releases(p->pi_lock) -+{ -+ raw_spin_unlock(&rq->lock); -+ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); -+} -+ -+static inline void -+rq_lock(struct rq *rq, struct rq_flags *rf) -+ __acquires(rq->lock) -+{ -+ raw_spin_lock(&rq->lock); -+} -+ -+static inline void -+rq_unlock_irq(struct rq *rq, struct rq_flags *rf) -+ __releases(rq->lock) -+{ -+ raw_spin_unlock_irq(&rq->lock); -+} -+ -+static inline void -+rq_unlock(struct rq *rq, struct rq_flags *rf) -+ __releases(rq->lock) -+{ -+ raw_spin_unlock(&rq->lock); -+} -+ -+static inline struct rq * -+this_rq_lock_irq(struct rq_flags *rf) -+ __acquires(rq->lock) -+{ -+ struct rq *rq; -+ -+ local_irq_disable(); -+ rq = this_rq(); -+ raw_spin_lock(&rq->lock); -+ -+ return rq; -+} -+ -+extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); -+extern void raw_spin_rq_unlock(struct rq *rq); -+ -+static inline raw_spinlock_t *__rq_lockp(struct rq *rq) -+{ -+ return &rq->lock; -+} -+ -+static inline raw_spinlock_t *rq_lockp(struct rq *rq) -+{ -+ return __rq_lockp(rq); -+} -+ -+static inline void raw_spin_rq_lock(struct rq *rq) -+{ -+ raw_spin_rq_lock_nested(rq, 0); -+} -+ -+static inline void raw_spin_rq_lock_irq(struct rq *rq) -+{ -+ local_irq_disable(); -+ raw_spin_rq_lock(rq); -+} -+ -+static inline void raw_spin_rq_unlock_irq(struct rq *rq) -+{ -+ raw_spin_rq_unlock(rq); -+ local_irq_enable(); -+} -+ -+static inline int task_current(struct rq *rq, struct task_struct *p) -+{ -+ return rq->curr == p; -+} -+ -+static inline bool task_running(struct task_struct *p) -+{ -+ return p->on_cpu; -+} -+ -+extern int task_running_nice(struct task_struct *p); -+ -+extern struct static_key_false sched_schedstats; -+ -+#ifdef CONFIG_CPU_IDLE -+static inline void idle_set_state(struct rq *rq, -+ struct cpuidle_state *idle_state) -+{ -+ rq->idle_state = idle_state; -+} -+ -+static inline struct cpuidle_state *idle_get_state(struct rq *rq) -+{ -+ WARN_ON(!rcu_read_lock_held()); -+ return rq->idle_state; -+} -+#else -+static inline void idle_set_state(struct rq *rq, -+ struct cpuidle_state *idle_state) -+{ -+} -+ -+static inline struct cpuidle_state *idle_get_state(struct rq *rq) -+{ -+ return NULL; -+} -+#endif -+ -+static inline int cpu_of(const struct rq *rq) -+{ -+#ifdef CONFIG_SMP -+ return rq->cpu; -+#else -+ return 0; -+#endif -+} -+ -+#include "stats.h" -+ -+#ifdef CONFIG_NO_HZ_COMMON -+#define NOHZ_BALANCE_KICK_BIT 0 -+#define NOHZ_STATS_KICK_BIT 1 -+ -+#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) -+#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) -+ -+#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) -+ -+#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) -+ -+/* TODO: needed? -+extern void nohz_balance_exit_idle(struct rq *rq); -+#else -+static inline void nohz_balance_exit_idle(struct rq *rq) { } -+*/ -+#endif -+ -+#ifdef CONFIG_IRQ_TIME_ACCOUNTING -+struct irqtime { -+ u64 total; -+ u64 tick_delta; -+ u64 irq_start_time; -+ struct u64_stats_sync sync; -+}; -+ -+DECLARE_PER_CPU(struct irqtime, cpu_irqtime); -+ -+/* -+ * Returns the irqtime minus the softirq time computed by ksoftirqd. -+ * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime -+ * and never move forward. -+ */ -+static inline u64 irq_time_read(int cpu) -+{ -+ struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); -+ unsigned int seq; -+ u64 total; -+ -+ do { -+ seq = __u64_stats_fetch_begin(&irqtime->sync); -+ total = irqtime->total; -+ } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); -+ -+ return total; -+} -+#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ -+ -+#ifdef CONFIG_CPU_FREQ -+DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); -+#endif /* CONFIG_CPU_FREQ */ -+ -+#ifdef CONFIG_NO_HZ_FULL -+extern int __init sched_tick_offload_init(void); -+#else -+static inline int sched_tick_offload_init(void) { return 0; } -+#endif -+ -+#ifdef arch_scale_freq_capacity -+#ifndef arch_scale_freq_invariant -+#define arch_scale_freq_invariant() (true) -+#endif -+#else /* arch_scale_freq_capacity */ -+#define arch_scale_freq_invariant() (false) -+#endif -+ -+extern void schedule_idle(void); -+ -+#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) -+ -+/* -+ * !! For sched_setattr_nocheck() (kernel) only !! -+ * -+ * This is actually gross. :( -+ * -+ * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE -+ * tasks, but still be able to sleep. We need this on platforms that cannot -+ * atomically change clock frequency. Remove once fast switching will be -+ * available on such platforms. -+ * -+ * SUGOV stands for SchedUtil GOVernor. -+ */ -+#define SCHED_FLAG_SUGOV 0x10000000 -+ -+#ifdef CONFIG_MEMBARRIER -+/* -+ * The scheduler provides memory barriers required by membarrier between: -+ * - prior user-space memory accesses and store to rq->membarrier_state, -+ * - store to rq->membarrier_state and following user-space memory accesses. -+ * In the same way it provides those guarantees around store to rq->curr. -+ */ -+static inline void membarrier_switch_mm(struct rq *rq, -+ struct mm_struct *prev_mm, -+ struct mm_struct *next_mm) -+{ -+ int membarrier_state; -+ -+ if (prev_mm == next_mm) -+ return; -+ -+ membarrier_state = atomic_read(&next_mm->membarrier_state); -+ if (READ_ONCE(rq->membarrier_state) == membarrier_state) -+ return; -+ -+ WRITE_ONCE(rq->membarrier_state, membarrier_state); -+} -+#else -+static inline void membarrier_switch_mm(struct rq *rq, -+ struct mm_struct *prev_mm, -+ struct mm_struct *next_mm) -+{ -+} -+#endif -+ -+#ifdef CONFIG_NUMA -+extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); -+#else -+static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) -+{ -+ return nr_cpu_ids; -+} -+#endif -+ -+extern void swake_up_all_locked(struct swait_queue_head *q); -+extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); -+ -+#ifdef CONFIG_PREEMPT_DYNAMIC -+extern int preempt_dynamic_mode; -+extern int sched_dynamic_mode(const char *str); -+extern void sched_dynamic_update(int mode); -+#endif -+ -+static inline void nohz_run_idle_balance(int cpu) { } -+#endif /* ALT_SCHED_H */ -diff --git a/kernel/sched/bmq.h b/kernel/sched/bmq.h -new file mode 100644 -index 000000000000..be3ee4a553ca ---- /dev/null -+++ b/kernel/sched/bmq.h -@@ -0,0 +1,111 @@ -+#define ALT_SCHED_VERSION_MSG "sched/bmq: BMQ CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" -+ -+/* -+ * BMQ only routines -+ */ -+#define rq_switch_time(rq) ((rq)->clock - (rq)->last_ts_switch) -+#define boost_threshold(p) (sched_timeslice_ns >>\ -+ (15 - MAX_PRIORITY_ADJ - (p)->boost_prio)) -+ -+static inline void boost_task(struct task_struct *p) -+{ -+ int limit; -+ -+ switch (p->policy) { -+ case SCHED_NORMAL: -+ limit = -MAX_PRIORITY_ADJ; -+ break; -+ case SCHED_BATCH: -+ case SCHED_IDLE: -+ limit = 0; -+ break; -+ default: -+ return; -+ } -+ -+ if (p->boost_prio > limit) -+ p->boost_prio--; -+} -+ -+static inline void deboost_task(struct task_struct *p) -+{ -+ if (p->boost_prio < MAX_PRIORITY_ADJ) -+ p->boost_prio++; -+} -+ -+/* -+ * Common interfaces -+ */ -+static inline void sched_timeslice_imp(const int timeslice_ms) {} -+ -+static inline int -+task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) -+{ -+ return p->prio + p->boost_prio - MAX_RT_PRIO; -+} -+ -+static inline int task_sched_prio(const struct task_struct *p) -+{ -+ return (p->prio < MAX_RT_PRIO)? p->prio : MAX_RT_PRIO / 2 + (p->prio + p->boost_prio) / 2; -+} -+ -+static inline int -+task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) -+{ -+ return task_sched_prio(p); -+} -+ -+static inline int sched_prio2idx(int prio, struct rq *rq) -+{ -+ return prio; -+} -+ -+static inline int sched_idx2prio(int idx, struct rq *rq) -+{ -+ return idx; -+} -+ -+static inline void time_slice_expired(struct task_struct *p, struct rq *rq) -+{ -+ p->time_slice = sched_timeslice_ns; -+ -+ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) { -+ if (SCHED_RR != p->policy) -+ deboost_task(p); -+ requeue_task(p, rq); -+ } -+} -+ -+static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) {} -+ -+inline int task_running_nice(struct task_struct *p) -+{ -+ return (p->prio + p->boost_prio > DEFAULT_PRIO + MAX_PRIORITY_ADJ); -+} -+ -+static void sched_task_fork(struct task_struct *p, struct rq *rq) -+{ -+ p->boost_prio = (p->boost_prio < 0) ? -+ p->boost_prio + MAX_PRIORITY_ADJ : MAX_PRIORITY_ADJ; -+} -+ -+static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) -+{ -+ p->boost_prio = MAX_PRIORITY_ADJ; -+} -+ -+#ifdef CONFIG_SMP -+static inline void sched_task_ttwu(struct task_struct *p) -+{ -+ if(this_rq()->clock_task - p->last_ran > sched_timeslice_ns) -+ boost_task(p); -+} -+#endif -+ -+static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) -+{ -+ if (rq_switch_time(rq) < boost_threshold(p)) -+ boost_task(p); -+} -+ -+static inline void update_rq_time_edge(struct rq *rq) {} -diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c -index e7af18857371..3e38816b736e 100644 ---- a/kernel/sched/cpufreq_schedutil.c -+++ b/kernel/sched/cpufreq_schedutil.c -@@ -167,9 +167,14 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu) - unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); - - sg_cpu->max = max; -+#ifndef CONFIG_SCHED_ALT - sg_cpu->bw_dl = cpu_bw_dl(rq); - sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(rq), max, - FREQUENCY_UTIL, NULL); -+#else -+ sg_cpu->bw_dl = 0; -+ sg_cpu->util = rq_load_util(rq, max); -+#endif /* CONFIG_SCHED_ALT */ - } - - /** -@@ -312,8 +317,10 @@ static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } - */ - static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu) - { -+#ifndef CONFIG_SCHED_ALT - if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) - sg_cpu->sg_policy->limits_changed = true; -+#endif - } - - static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, -@@ -607,6 +614,7 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy) - } - - ret = sched_setattr_nocheck(thread, &attr); -+ - if (ret) { - kthread_stop(thread); - pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); -@@ -839,7 +847,9 @@ cpufreq_governor_init(schedutil_gov); - #ifdef CONFIG_ENERGY_MODEL - static void rebuild_sd_workfn(struct work_struct *work) - { -+#ifndef CONFIG_SCHED_ALT - rebuild_sched_domains_energy(); -+#endif /* CONFIG_SCHED_ALT */ - } - static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); - -diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c -index 872e481d5098..f920c8b48ec1 100644 ---- a/kernel/sched/cputime.c -+++ b/kernel/sched/cputime.c -@@ -123,7 +123,7 @@ void account_user_time(struct task_struct *p, u64 cputime) - p->utime += cputime; - account_group_user_time(p, cputime); - -- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; -+ index = task_running_nice(p) ? CPUTIME_NICE : CPUTIME_USER; - - /* Add user time to cpustat. */ - task_group_account_field(p, index, cputime); -@@ -147,7 +147,7 @@ void account_guest_time(struct task_struct *p, u64 cputime) - p->gtime += cputime; - - /* Add guest time to cpustat. */ -- if (task_nice(p) > 0) { -+ if (task_running_nice(p)) { - cpustat[CPUTIME_NICE] += cputime; - cpustat[CPUTIME_GUEST_NICE] += cputime; - } else { -@@ -270,7 +270,7 @@ static inline u64 account_other_time(u64 max) - #ifdef CONFIG_64BIT - static inline u64 read_sum_exec_runtime(struct task_struct *t) - { -- return t->se.sum_exec_runtime; -+ return tsk_seruntime(t); - } - #else - static u64 read_sum_exec_runtime(struct task_struct *t) -@@ -280,7 +280,7 @@ static u64 read_sum_exec_runtime(struct task_struct *t) - struct rq *rq; - - rq = task_rq_lock(t, &rf); -- ns = t->se.sum_exec_runtime; -+ ns = tsk_seruntime(t); - task_rq_unlock(rq, t, &rf); - - return ns; -@@ -612,7 +612,7 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, - void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st) - { - struct task_cputime cputime = { -- .sum_exec_runtime = p->se.sum_exec_runtime, -+ .sum_exec_runtime = tsk_seruntime(p), - }; - - task_cputime(p, &cputime.utime, &cputime.stime); -diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c -index 17a653b67006..17ab2fe34d7a 100644 ---- a/kernel/sched/debug.c -+++ b/kernel/sched/debug.c -@@ -8,6 +8,7 @@ - */ - #include "sched.h" - -+#ifndef CONFIG_SCHED_ALT - /* - * This allows printing both to /proc/sched_debug and - * to the console -@@ -216,6 +217,7 @@ static const struct file_operations sched_scaling_fops = { - }; - - #endif /* SMP */ -+#endif /* !CONFIG_SCHED_ALT */ - - #ifdef CONFIG_PREEMPT_DYNAMIC - -@@ -279,6 +281,7 @@ static const struct file_operations sched_dynamic_fops = { - - #endif /* CONFIG_PREEMPT_DYNAMIC */ - -+#ifndef CONFIG_SCHED_ALT - __read_mostly bool sched_debug_verbose; - - static const struct seq_operations sched_debug_sops; -@@ -294,6 +297,7 @@ static const struct file_operations sched_debug_fops = { - .llseek = seq_lseek, - .release = seq_release, - }; -+#endif /* !CONFIG_SCHED_ALT */ - - static struct dentry *debugfs_sched; - -@@ -303,12 +307,15 @@ static __init int sched_init_debug(void) - - debugfs_sched = debugfs_create_dir("sched", NULL); - -+#ifndef CONFIG_SCHED_ALT - debugfs_create_file("features", 0644, debugfs_sched, NULL, &sched_feat_fops); - debugfs_create_bool("verbose", 0644, debugfs_sched, &sched_debug_verbose); -+#endif /* !CONFIG_SCHED_ALT */ - #ifdef CONFIG_PREEMPT_DYNAMIC - debugfs_create_file("preempt", 0644, debugfs_sched, NULL, &sched_dynamic_fops); - #endif - -+#ifndef CONFIG_SCHED_ALT - debugfs_create_u32("latency_ns", 0644, debugfs_sched, &sysctl_sched_latency); - debugfs_create_u32("min_granularity_ns", 0644, debugfs_sched, &sysctl_sched_min_granularity); - debugfs_create_u32("wakeup_granularity_ns", 0644, debugfs_sched, &sysctl_sched_wakeup_granularity); -@@ -336,11 +343,13 @@ static __init int sched_init_debug(void) - #endif - - debugfs_create_file("debug", 0444, debugfs_sched, NULL, &sched_debug_fops); -+#endif /* !CONFIG_SCHED_ALT */ - - return 0; - } - late_initcall(sched_init_debug); - -+#ifndef CONFIG_SCHED_ALT - #ifdef CONFIG_SMP - - static cpumask_var_t sd_sysctl_cpus; -@@ -1063,6 +1072,7 @@ void proc_sched_set_task(struct task_struct *p) - memset(&p->se.statistics, 0, sizeof(p->se.statistics)); - #endif - } -+#endif /* !CONFIG_SCHED_ALT */ - - void resched_latency_warn(int cpu, u64 latency) - { -diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c -index d17b0a5ce6ac..6ff77fc6b73a 100644 ---- a/kernel/sched/idle.c -+++ b/kernel/sched/idle.c -@@ -403,6 +403,7 @@ void cpu_startup_entry(enum cpuhp_state state) - do_idle(); - } - -+#ifndef CONFIG_SCHED_ALT - /* - * idle-task scheduling class. - */ -@@ -525,3 +526,4 @@ DEFINE_SCHED_CLASS(idle) = { - .switched_to = switched_to_idle, - .update_curr = update_curr_idle, - }; -+#endif -diff --git a/kernel/sched/pds.h b/kernel/sched/pds.h -new file mode 100644 -index 000000000000..0f1f0d708b77 ---- /dev/null -+++ b/kernel/sched/pds.h -@@ -0,0 +1,127 @@ -+#define ALT_SCHED_VERSION_MSG "sched/pds: PDS CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" -+ -+static int sched_timeslice_shift = 22; -+ -+#define NORMAL_PRIO_MOD(x) ((x) & (NORMAL_PRIO_NUM - 1)) -+ -+/* -+ * Common interfaces -+ */ -+static inline void sched_timeslice_imp(const int timeslice_ms) -+{ -+ if (2 == timeslice_ms) -+ sched_timeslice_shift = 21; -+} -+ -+static inline int -+task_sched_prio_normal(const struct task_struct *p, const struct rq *rq) -+{ -+ s64 delta = p->deadline - rq->time_edge + NORMAL_PRIO_NUM - NICE_WIDTH; -+ -+ if (WARN_ONCE(delta > NORMAL_PRIO_NUM - 1, -+ "pds: task_sched_prio_normal() delta %lld\n", delta)) -+ return NORMAL_PRIO_NUM - 1; -+ -+ return (delta < 0) ? 0 : delta; -+} -+ -+static inline int task_sched_prio(const struct task_struct *p) -+{ -+ return (p->prio < MAX_RT_PRIO) ? p->prio : -+ MIN_NORMAL_PRIO + task_sched_prio_normal(p, task_rq(p)); -+} -+ -+static inline int -+task_sched_prio_idx(const struct task_struct *p, const struct rq *rq) -+{ -+ return (p->prio < MAX_RT_PRIO) ? p->prio : MIN_NORMAL_PRIO + -+ NORMAL_PRIO_MOD(task_sched_prio_normal(p, rq) + rq->time_edge); -+} -+ -+static inline int sched_prio2idx(int prio, struct rq *rq) -+{ -+ return (IDLE_TASK_SCHED_PRIO == prio || prio < MAX_RT_PRIO) ? prio : -+ MIN_NORMAL_PRIO + NORMAL_PRIO_MOD((prio - MIN_NORMAL_PRIO) + -+ rq->time_edge); -+} -+ -+static inline int sched_idx2prio(int idx, struct rq *rq) -+{ -+ return (idx < MAX_RT_PRIO) ? idx : MIN_NORMAL_PRIO + -+ NORMAL_PRIO_MOD((idx - MIN_NORMAL_PRIO) + NORMAL_PRIO_NUM - -+ NORMAL_PRIO_MOD(rq->time_edge)); -+} -+ -+static inline void sched_renew_deadline(struct task_struct *p, const struct rq *rq) -+{ -+ if (p->prio >= MAX_RT_PRIO) -+ p->deadline = (rq->clock >> sched_timeslice_shift) + -+ p->static_prio - (MAX_PRIO - NICE_WIDTH); -+} -+ -+int task_running_nice(struct task_struct *p) -+{ -+ return (p->prio > DEFAULT_PRIO); -+} -+ -+static inline void update_rq_time_edge(struct rq *rq) -+{ -+ struct list_head head; -+ u64 old = rq->time_edge; -+ u64 now = rq->clock >> sched_timeslice_shift; -+ u64 prio, delta; -+ -+ if (now == old) -+ return; -+ -+ delta = min_t(u64, NORMAL_PRIO_NUM, now - old); -+ INIT_LIST_HEAD(&head); -+ -+ for_each_set_bit(prio, &rq->queue.bitmap[2], delta) -+ list_splice_tail_init(rq->queue.heads + MIN_NORMAL_PRIO + -+ NORMAL_PRIO_MOD(prio + old), &head); -+ -+ rq->queue.bitmap[2] = (NORMAL_PRIO_NUM == delta) ? 0UL : -+ rq->queue.bitmap[2] >> delta; -+ rq->time_edge = now; -+ if (!list_empty(&head)) { -+ u64 idx = MIN_NORMAL_PRIO + NORMAL_PRIO_MOD(now); -+ struct task_struct *p; -+ -+ list_for_each_entry(p, &head, sq_node) -+ p->sq_idx = idx; -+ -+ list_splice(&head, rq->queue.heads + idx); -+ rq->queue.bitmap[2] |= 1UL; -+ } -+} -+ -+static inline void time_slice_expired(struct task_struct *p, struct rq *rq) -+{ -+ p->time_slice = sched_timeslice_ns; -+ sched_renew_deadline(p, rq); -+ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) -+ requeue_task(p, rq); -+} -+ -+static inline void sched_task_sanity_check(struct task_struct *p, struct rq *rq) -+{ -+ u64 max_dl = rq->time_edge + NICE_WIDTH - 1; -+ if (unlikely(p->deadline > max_dl)) -+ p->deadline = max_dl; -+} -+ -+static void sched_task_fork(struct task_struct *p, struct rq *rq) -+{ -+ sched_renew_deadline(p, rq); -+} -+ -+static inline void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) -+{ -+ time_slice_expired(p, rq); -+} -+ -+#ifdef CONFIG_SMP -+static inline void sched_task_ttwu(struct task_struct *p) {} -+#endif -+static inline void sched_task_deactivate(struct task_struct *p, struct rq *rq) {} -diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c -index a554e3bbab2b..3e56f5e6ff5c 100644 ---- a/kernel/sched/pelt.c -+++ b/kernel/sched/pelt.c -@@ -270,6 +270,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load) - WRITE_ONCE(sa->util_avg, sa->util_sum / divider); - } - -+#ifndef CONFIG_SCHED_ALT - /* - * sched_entity: - * -@@ -387,8 +388,9 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) - - return 0; - } -+#endif - --#ifdef CONFIG_SCHED_THERMAL_PRESSURE -+#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) - /* - * thermal: - * -diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h -index e06071bf3472..adf567df34d4 100644 ---- a/kernel/sched/pelt.h -+++ b/kernel/sched/pelt.h -@@ -1,13 +1,15 @@ - #ifdef CONFIG_SMP - #include "sched-pelt.h" - -+#ifndef CONFIG_SCHED_ALT - int __update_load_avg_blocked_se(u64 now, struct sched_entity *se); - int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se); - int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq); - int update_rt_rq_load_avg(u64 now, struct rq *rq, int running); - int update_dl_rq_load_avg(u64 now, struct rq *rq, int running); -+#endif - --#ifdef CONFIG_SCHED_THERMAL_PRESSURE -+#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) - int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity); - - static inline u64 thermal_load_avg(struct rq *rq) -@@ -42,6 +44,7 @@ static inline u32 get_pelt_divider(struct sched_avg *avg) - return LOAD_AVG_MAX - 1024 + avg->period_contrib; - } - -+#ifndef CONFIG_SCHED_ALT - static inline void cfs_se_util_change(struct sched_avg *avg) - { - unsigned int enqueued; -@@ -153,9 +156,11 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) - return rq_clock_pelt(rq_of(cfs_rq)); - } - #endif -+#endif /* CONFIG_SCHED_ALT */ - - #else - -+#ifndef CONFIG_SCHED_ALT - static inline int - update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) - { -@@ -173,6 +178,7 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running) - { - return 0; - } -+#endif - - static inline int - update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity) -diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h -index 3d3e5793e117..c1d976ef623f 100644 ---- a/kernel/sched/sched.h -+++ b/kernel/sched/sched.h -@@ -2,6 +2,10 @@ - /* - * Scheduler internal types and methods: - */ -+#ifdef CONFIG_SCHED_ALT -+#include "alt_sched.h" -+#else -+ - #include <linux/sched.h> - - #include <linux/sched/autogroup.h> -@@ -3064,3 +3068,8 @@ extern int sched_dynamic_mode(const char *str); - extern void sched_dynamic_update(int mode); - #endif - -+static inline int task_running_nice(struct task_struct *p) -+{ -+ return (task_nice(p) > 0); -+} -+#endif /* !CONFIG_SCHED_ALT */ -diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c -index 3f93fc3b5648..528b71e144e9 100644 ---- a/kernel/sched/stats.c -+++ b/kernel/sched/stats.c -@@ -22,8 +22,10 @@ static int show_schedstat(struct seq_file *seq, void *v) - } else { - struct rq *rq; - #ifdef CONFIG_SMP -+#ifndef CONFIG_SCHED_ALT - struct sched_domain *sd; - int dcount = 0; -+#endif - #endif - cpu = (unsigned long)(v - 2); - rq = cpu_rq(cpu); -@@ -40,6 +42,7 @@ static int show_schedstat(struct seq_file *seq, void *v) - seq_printf(seq, "\n"); - - #ifdef CONFIG_SMP -+#ifndef CONFIG_SCHED_ALT - /* domain-specific stats */ - rcu_read_lock(); - for_each_domain(cpu, sd) { -@@ -68,6 +71,7 @@ static int show_schedstat(struct seq_file *seq, void *v) - sd->ttwu_move_balance); - } - rcu_read_unlock(); -+#endif - #endif - } - return 0; -diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c -index 4e8698e62f07..36c61551252e 100644 ---- a/kernel/sched/topology.c -+++ b/kernel/sched/topology.c -@@ -4,6 +4,7 @@ - */ - #include "sched.h" - -+#ifndef CONFIG_SCHED_ALT - DEFINE_MUTEX(sched_domains_mutex); - - /* Protected by sched_domains_mutex: */ -@@ -1382,8 +1383,10 @@ static void asym_cpu_capacity_scan(void) - */ - - static int default_relax_domain_level = -1; -+#endif /* CONFIG_SCHED_ALT */ - int sched_domain_level_max; - -+#ifndef CONFIG_SCHED_ALT - static int __init setup_relax_domain_level(char *str) - { - if (kstrtoint(str, 0, &default_relax_domain_level)) -@@ -1619,6 +1622,7 @@ sd_init(struct sched_domain_topology_level *tl, - - return sd; - } -+#endif /* CONFIG_SCHED_ALT */ - - /* - * Topology list, bottom-up. -@@ -1648,6 +1652,7 @@ void set_sched_topology(struct sched_domain_topology_level *tl) - sched_domain_topology = tl; - } - -+#ifndef CONFIG_SCHED_ALT - #ifdef CONFIG_NUMA - - static const struct cpumask *sd_numa_mask(int cpu) -@@ -2516,3 +2521,17 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], - partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); - mutex_unlock(&sched_domains_mutex); - } -+#else /* CONFIG_SCHED_ALT */ -+void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], -+ struct sched_domain_attr *dattr_new) -+{} -+ -+#ifdef CONFIG_NUMA -+int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE; -+ -+int sched_numa_find_closest(const struct cpumask *cpus, int cpu) -+{ -+ return best_mask_cpu(cpu, cpus); -+} -+#endif /* CONFIG_NUMA */ -+#endif -diff --git a/kernel/sysctl.c b/kernel/sysctl.c -index 083be6af29d7..09fc6281d488 100644 ---- a/kernel/sysctl.c -+++ b/kernel/sysctl.c -@@ -122,6 +122,10 @@ static unsigned long long_max = LONG_MAX; - static int one_hundred = 100; - static int two_hundred = 200; - static int one_thousand = 1000; -+#ifdef CONFIG_SCHED_ALT -+static int __maybe_unused zero = 0; -+extern int sched_yield_type; -+#endif - #ifdef CONFIG_PRINTK - static int ten_thousand = 10000; - #endif -@@ -1771,6 +1775,24 @@ int proc_do_static_key(struct ctl_table *table, int write, - } - - static struct ctl_table kern_table[] = { -+#ifdef CONFIG_SCHED_ALT -+/* In ALT, only supported "sched_schedstats" */ -+#ifdef CONFIG_SCHED_DEBUG -+#ifdef CONFIG_SMP -+#ifdef CONFIG_SCHEDSTATS -+ { -+ .procname = "sched_schedstats", -+ .data = NULL, -+ .maxlen = sizeof(unsigned int), -+ .mode = 0644, -+ .proc_handler = sysctl_schedstats, -+ .extra1 = SYSCTL_ZERO, -+ .extra2 = SYSCTL_ONE, -+ }, -+#endif /* CONFIG_SCHEDSTATS */ -+#endif /* CONFIG_SMP */ -+#endif /* CONFIG_SCHED_DEBUG */ -+#else /* !CONFIG_SCHED_ALT */ - { - .procname = "sched_child_runs_first", - .data = &sysctl_sched_child_runs_first, -@@ -1901,6 +1923,7 @@ static struct ctl_table kern_table[] = { - .extra2 = SYSCTL_ONE, - }, - #endif -+#endif /* !CONFIG_SCHED_ALT */ - #ifdef CONFIG_PROVE_LOCKING - { - .procname = "prove_locking", -@@ -2477,6 +2500,17 @@ static struct ctl_table kern_table[] = { - .proc_handler = proc_dointvec, - }, - #endif -+#ifdef CONFIG_SCHED_ALT -+ { -+ .procname = "yield_type", -+ .data = &sched_yield_type, -+ .maxlen = sizeof (int), -+ .mode = 0644, -+ .proc_handler = &proc_dointvec_minmax, -+ .extra1 = &zero, -+ .extra2 = &two, -+ }, -+#endif - #if defined(CONFIG_S390) && defined(CONFIG_SMP) - { - .procname = "spin_retry", -diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c -index 0ea8702eb516..a27a0f3a654d 100644 ---- a/kernel/time/hrtimer.c -+++ b/kernel/time/hrtimer.c -@@ -2088,8 +2088,10 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, - int ret = 0; - u64 slack; - -+#ifndef CONFIG_SCHED_ALT - slack = current->timer_slack_ns; - if (dl_task(current) || rt_task(current)) -+#endif - slack = 0; - - hrtimer_init_sleeper_on_stack(&t, clockid, mode); -diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c -index 643d412ac623..6bf27565242f 100644 ---- a/kernel/time/posix-cpu-timers.c -+++ b/kernel/time/posix-cpu-timers.c -@@ -216,7 +216,7 @@ static void task_sample_cputime(struct task_struct *p, u64 *samples) - u64 stime, utime; - - task_cputime(p, &utime, &stime); -- store_samples(samples, stime, utime, p->se.sum_exec_runtime); -+ store_samples(samples, stime, utime, tsk_seruntime(p)); - } - - static void proc_sample_cputime_atomic(struct task_cputime_atomic *at, -@@ -859,6 +859,7 @@ static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples, - } - } - -+#ifndef CONFIG_SCHED_ALT - static inline void check_dl_overrun(struct task_struct *tsk) - { - if (tsk->dl.dl_overrun) { -@@ -866,6 +867,7 @@ static inline void check_dl_overrun(struct task_struct *tsk) - __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); - } - } -+#endif - - static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) - { -@@ -893,8 +895,10 @@ static void check_thread_timers(struct task_struct *tsk, - u64 samples[CPUCLOCK_MAX]; - unsigned long soft; - -+#ifndef CONFIG_SCHED_ALT - if (dl_task(tsk)) - check_dl_overrun(tsk); -+#endif - - if (expiry_cache_is_inactive(pct)) - return; -@@ -908,7 +912,7 @@ static void check_thread_timers(struct task_struct *tsk, - soft = task_rlimit(tsk, RLIMIT_RTTIME); - if (soft != RLIM_INFINITY) { - /* Task RT timeout is accounted in jiffies. RTTIME is usec */ -- unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ); -+ unsigned long rttime = tsk_rttimeout(tsk) * (USEC_PER_SEC / HZ); - unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME); - - /* At the hard limit, send SIGKILL. No further action. */ -@@ -1144,8 +1148,10 @@ static inline bool fastpath_timer_check(struct task_struct *tsk) - return true; - } - -+#ifndef CONFIG_SCHED_ALT - if (dl_task(tsk) && tsk->dl.dl_overrun) - return true; -+#endif - - return false; - } -diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c -index adf7ef194005..11c8f36e281b 100644 ---- a/kernel/trace/trace_selftest.c -+++ b/kernel/trace/trace_selftest.c -@@ -1052,10 +1052,15 @@ static int trace_wakeup_test_thread(void *data) - { - /* Make this a -deadline thread */ - static const struct sched_attr attr = { -+#ifdef CONFIG_SCHED_ALT -+ /* No deadline on BMQ/PDS, use RR */ -+ .sched_policy = SCHED_RR, -+#else - .sched_policy = SCHED_DEADLINE, - .sched_runtime = 100000ULL, - .sched_deadline = 10000000ULL, - .sched_period = 10000000ULL -+#endif - }; - struct wakeup_test_data *x = data; - ---- a/kernel/sched/alt_core.c 2021-11-19 09:43:18.978378235 -0500 -+++ b/kernel/sched/alt_core.c 2021-11-19 09:44:22.692033290 -0500 -@@ -2994,7 +2994,7 @@ int sched_fork(unsigned long clone_flags - return 0; - } - --void sched_post_fork(struct task_struct *p) {} -+void sched_post_fork(struct task_struct *p, struct kernel_clone_args *kargs) {} - - #ifdef CONFIG_SCHEDSTATS - |