sched: Optimize unused cgroup configuration

When cgroup group scheduling is built in, skip some code paths
if we don't have any (but the root) cgroups configured.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-06-03 15:41:20 +02:00 committed by Ingo Molnar
parent a5004278f0
commit e709715915
1 changed files with 14 additions and 2 deletions

View File

@ -1629,8 +1629,14 @@ static int tg_load_down(struct task_group *tg, void *data)
static void update_shares(struct sched_domain *sd)
{
u64 now = cpu_clock(raw_smp_processor_id());
s64 elapsed = now - sd->last_update;
s64 elapsed;
u64 now;
if (root_task_group_empty())
return;
now = cpu_clock(raw_smp_processor_id());
elapsed = now - sd->last_update;
if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
sd->last_update = now;
@ -1640,6 +1646,9 @@ static void update_shares(struct sched_domain *sd)
static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
{
if (root_task_group_empty())
return;
spin_unlock(&rq->lock);
update_shares(sd);
spin_lock(&rq->lock);
@ -1647,6 +1656,9 @@ static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
static void update_h_load(long cpu)
{
if (root_task_group_empty())
return;
walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
}