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sched: group scheduler wakeup latency fix

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group scheduler wakeup latency fix: when checking for preemption
we must check cross-group too, not just intra-group.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Srivatsa Vaddagiri 2007-10-15 17:00:12 +02:00 committed by Ingo Molnar
parent 57cb499df2
commit 8651a86c34
1 changed files with 16 additions and 5 deletions
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21
kernel/sched_fair.c
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@ -796,7 +796,8 @@ static void yield_task_fair(struct rq *rq)
static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
{
struct task_struct *curr = rq->curr;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
struct cfs_rq *cfs_rq = task_cfs_rq(curr), *pcfs_rq;
struct sched_entity *se = &curr->se, *pse = &p->se;
if (unlikely(rt_prio(p->prio))) {
update_rq_clock(rq);
@ -804,11 +805,21 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p)
resched_task(curr);
return;
}
if (is_same_group(curr, p)) {
s64 delta = curr->se.vruntime - p->se.vruntime;
if (delta > (s64)sysctl_sched_wakeup_granularity)
resched_task(curr);
for_each_sched_entity(se) {
cfs_rq = cfs_rq_of(se);
pcfs_rq = cfs_rq_of(pse);
if (cfs_rq == pcfs_rq) {
s64 delta = se->vruntime - pse->vruntime;
if (delta > (s64)sysctl_sched_wakeup_granularity)
resched_task(curr);
break;
}
#ifdef CONFIG_FAIR_GROUP_SCHED
pse = pse->parent;
#endif
}
}