From 8b81fc185ab13feca2f63eda3792189e5ac11a97 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 13 Sep 2022 07:35:13 +0200 Subject: [PATCH 80/87] tools/xenstore: make the internal memory data base the default Having a file backed data base has the only advantage of being capable to dump the contents of it while Xenstore is running, and potentially using less swap space in case the data base can't be kept in memory. It has the major disadvantage of a huge performance overhead: switching to keep the data base in memory only speeds up live update of xenstored with 120000 nodes from 20 minutes to 11 seconds. A complete tree walk of this configuration will be reduced from 7 seconds to 280 msecs (measured by "xenstore-control check"). So make the internal memory data base the default and enhance the "--internal-db" command line parameter to take an optional parameter allowing to switch the internal data base back to the file based one. This is part of XSA-419. Signed-off-by: Juergen Gross Reviewed-by: Julien Grall (cherry picked from commit d174fefa90487ddd25ebc618028f67b2e8a1f795) --- tools/helpers/init-xenstore-domain.c | 4 ++-- tools/xenstore/xenstored_core.c | 13 ++++++++----- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/tools/helpers/init-xenstore-domain.c b/tools/helpers/init-xenstore-domain.c index 11ebf79e6d26..8d1d1a4f1e3a 100644 --- a/tools/helpers/init-xenstore-domain.c +++ b/tools/helpers/init-xenstore-domain.c @@ -223,9 +223,9 @@ static int build(xc_interface *xch) } if ( param ) - snprintf(cmdline, 512, "--event %d --internal-db %s", rv, param); + snprintf(cmdline, 512, "--event %d %s", rv, param); else - snprintf(cmdline, 512, "--event %d --internal-db", rv); + snprintf(cmdline, 512, "--event %d", rv); dom->guest_domid = domid; dom->cmdline = xc_dom_strdup(dom, cmdline); diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 0ca1a5a19ac2..041124d8b7a5 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -2329,7 +2329,7 @@ static void accept_connection(int sock) } #endif -static int tdb_flags; +static int tdb_flags = TDB_INTERNAL | TDB_NOLOCK; /* We create initial nodes manually. */ static void manual_node(const char *name, const char *child) @@ -2639,7 +2639,8 @@ static void usage(void) " watch-event: time a watch-event is kept pending\n" " -R, --no-recovery to request that no recovery should be attempted when\n" " the store is corrupted (debug only),\n" -" -I, --internal-db store database in memory, not on disk\n" +" -I, --internal-db [on|off] store database in memory, not on disk, default is\n" +" memory, with \"--internal-db off\" it is on disk\n" " -K, --keep-orphans don't delete nodes owned by a domain when the\n" " domain is deleted (this is a security risk!)\n" " -V, --verbose to request verbose execution.\n"); @@ -2665,7 +2666,7 @@ static struct option options[] = { { "quota-soft", 1, NULL, 'q' }, { "timeout", 1, NULL, 'w' }, { "no-recovery", 0, NULL, 'R' }, - { "internal-db", 0, NULL, 'I' }, + { "internal-db", 2, NULL, 'I' }, { "keep-orphans", 0, NULL, 'K' }, { "verbose", 0, NULL, 'V' }, { "watch-nb", 1, NULL, 'W' }, @@ -2746,7 +2747,8 @@ int main(int argc, char *argv[]) orig_argc = argc; orig_argv = argv; - while ((opt = getopt_long(argc, argv, "DE:F:HKNPS:t:A:M:Q:q:T:RVW:w:U", + while ((opt = getopt_long(argc, argv, + "DE:F:HI::KNPS:t:A:M:Q:q:T:RVW:w:U", options, NULL)) != -1) { switch (opt) { case 'D': @@ -2780,7 +2782,8 @@ int main(int argc, char *argv[]) tracefile = optarg; break; case 'I': - tdb_flags = TDB_INTERNAL|TDB_NOLOCK; + if (optarg && !strcmp(optarg, "off")) + tdb_flags = 0; break; case 'K': keep_orphans = true; -- 2.37.4