sched: Update rq clock before calling check_preempt_curr()

check_preempt_curr() of fair class needs an uptodate sched clock
value to update runtime stats of the current task of the target's rq.

When a task is woken up, activate_task() is usually called right before
ttwu_do_wakeup() unless the task is still in the runqueue. In the latter
case we need to update the rq clock explicitly because activate_task()
isn't here to do the job for us.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Turner <pjt@google.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1365724262-20142-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Frederic Weisbecker 2013-04-12 01:51:00 +02:00 committed by Ingo Molnar
parent 71b1da46ff
commit 1ad4ec0dc7

View File

@ -1365,6 +1365,8 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
rq = __task_rq_lock(p);
if (p->on_rq) {
/* check_preempt_curr() may use rq clock */
update_rq_clock(rq);
ttwu_do_wakeup(rq, p, wake_flags);
ret = 1;
}