From c372e817afc629fea9ff6321313325ed0b4a855b Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 25 Jul 2008 01:47:23 -0700 Subject: [PATCH] cpuset: avoid unnecessary sched domains rebuilding When changing 'sched_relax_domain_level', don't rebuild sched domains if 'cpus' is empty or 'sched_load_balance' is not set. Also make the comments of rebuild_sched_domains() more readable. Signed-off-by: Li Zefan Cc: Hidetoshi Seto Cc: Paul Jackson Cc: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 6eae6639e8..60d2c4702c 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -496,11 +496,16 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) /* * rebuild_sched_domains() * - * If the flag 'sched_load_balance' of any cpuset with non-empty - * 'cpus' changes, or if the 'cpus' allowed changes in any cpuset - * which has that flag enabled, or if any cpuset with a non-empty - * 'cpus' is removed, then call this routine to rebuild the - * scheduler's dynamic sched domains. + * This routine will be called to rebuild the scheduler's dynamic + * sched domains: + * - if the flag 'sched_load_balance' of any cpuset with non-empty + * 'cpus' changes, + * - or if the 'cpus' allowed changes in any cpuset which has that + * flag enabled, + * - or if the 'sched_relax_domain_level' of any cpuset which has + * that flag enabled and with non-empty 'cpus' changes, + * - or if any cpuset with non-empty 'cpus' is removed, + * - or if a cpu gets offlined. * * This routine builds a partial partition of the systems CPUs * (the set of non-overlappping cpumask_t's in the array 'part' @@ -1076,7 +1081,8 @@ static int update_relax_domain_level(struct cpuset *cs, s64 val) if (val != cs->relax_domain_level) { cs->relax_domain_level = val; - rebuild_sched_domains(); + if (!cpus_empty(cs->cpus_allowed) && is_sched_load_balance(cs)) + rebuild_sched_domains(); } return 0; -- 2.39.5