From 03e89e4574a680af15f59329b061f35d9813aff4 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Tue, 16 Dec 2008 08:45:30 +0100 Subject: [PATCH] sched: fix wakeup preemption clock Impact: sharpen the wakeup-granularity to always be against current scheduler time It was possible to do the preemption check against an old time stamp. Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- kernel/sched_fair.c | 7 +++---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index ad7b93be5691..88215066efae 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2266,6 +2266,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) smp_wmb(); rq = task_rq_lock(p, &flags); + update_rq_clock(rq); old_state = p->state; if (!(old_state & state)) goto out; @@ -2323,7 +2324,6 @@ out_activate: schedstat_inc(p, se.nr_wakeups_local); else schedstat_inc(p, se.nr_wakeups_remote); - update_rq_clock(rq); activate_task(rq, p, 1); success = 1; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 98345e45b059..928cd74cff0d 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1345,12 +1345,11 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; + struct cfs_rq *cfs_rq = task_cfs_rq(curr); + + update_curr(cfs_rq); if (unlikely(rt_prio(p->prio))) { - struct cfs_rq *cfs_rq = task_cfs_rq(curr); - - update_rq_clock(rq); - update_curr(cfs_rq); resched_task(curr); return; }