From 8651a86c342ab79a956afec0c5971acaad38d3a1 Mon Sep 17 00:00:00 2001 From: Srivatsa Vaddagiri Date: Mon, 15 Oct 2007 17:00:12 +0200 Subject: sched: group scheduler wakeup latency fix group scheduler wakeup latency fix: when checking for preemption we must check cross-group too, not just intra-group. Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) (limited to 'kernel/sched_fair.c') diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 48c69211888f..5384a977c9a7 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -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 } } -- cgit v1.2.3