From 71e20f1873d46e138c26ce83f8fe54b7221f572f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 15 Oct 2007 17:00:19 +0200 Subject: sched: affine sync wakeups make sync wakeups affine for cache-cold tasks: if a cache-cold task is woken up by a sync wakeup then use the opportunity to migrate it straight away. (the two tasks are 'related' because they communicate) Signed-off-by: Ingo Molnar --- kernel/sched.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 5a91fe0b5de..7fd34346259 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1521,6 +1521,12 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) unsigned long tl = this_load; unsigned long tl_per_task; + /* + * Attract cache-cold tasks on sync wakeups: + */ + if (sync && !task_hot(p, rq->clock, this_sd)) + goto out_set_cpu; + schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); @@ -1598,7 +1604,7 @@ out_activate: * the waker guarantees that the freshly woken up task is going * to be considered on this CPU.) */ - if (!sync || cpu != this_cpu) + if (!sync || rq->curr == rq->idle) check_preempt_curr(rq, p); success = 1; -- cgit v1.2.3