From f5393693e96393131a4a2e2743f883986d508503 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 29 Jul 2008 22:33:22 -0700 Subject: cpuset: speed up sched domain partition All child cpusets contain a subset of the parent's cpus, so we can skip them when partitioning sched domains. This decreases 'csa' greately for cpusets with multi-level hierarchy. Signed-off-by: Lai Jiangshan Signed-off-by: Li Zefan Cc: Paul Menage Cc: Cedric Le Goater Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki Reviewed-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) (limited to 'kernel/cpuset.c') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 3624dc0e95e..c818c36b0c5 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -486,13 +486,38 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) static void update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) { - if (!dattr) - return; if (dattr->relax_domain_level < c->relax_domain_level) dattr->relax_domain_level = c->relax_domain_level; return; } +static void +update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) +{ + LIST_HEAD(q); + + list_add(&c->stack_list, &q); + while (!list_empty(&q)) { + struct cpuset *cp; + struct cgroup *cont; + struct cpuset *child; + + cp = list_first_entry(&q, struct cpuset, stack_list); + list_del(q.next); + + if (cpus_empty(cp->cpus_allowed)) + continue; + + if (is_sched_load_balance(cp)) + update_domain_attr(dattr, cp); + + list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { + child = cgroup_cs(cont); + list_add_tail(&child->stack_list, &q); + } + } +} + /* * rebuild_sched_domains() * @@ -614,8 +639,16 @@ void rebuild_sched_domains(void) if (cpus_empty(cp->cpus_allowed)) continue; - if (is_sched_load_balance(cp)) + /* + * All child cpusets contain a subset of the parent's cpus, so + * just skip them, and then we call update_domain_attr_tree() + * to calc relax_domain_level of the corresponding sched + * domain. + */ + if (is_sched_load_balance(cp)) { csa[csn++] = cp; + continue; + } list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { child = cgroup_cs(cont); @@ -686,7 +719,7 @@ restart: cpus_or(*dp, *dp, b->cpus_allowed); b->pn = -1; if (dattr) - update_domain_attr(dattr + update_domain_attr_tree(dattr + nslot, b); } } -- cgit v1.2.3