39 lines
1.4 KiB
Diff
39 lines
1.4 KiB
Diff
From: Peter Zijlstra <peterz@infradead.org>
|
|
Date: Thu, 19 Aug 2010 11:31:43 +0000 (+0200)
|
|
Subject: sched: Fix rq->clock synchronization when migrating tasks
|
|
X-Git-Tag: v2.6.36-rc3~25^2~1
|
|
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=861d034ee814917a83bd5de4b26e3b8336ddeeb8
|
|
|
|
sched: Fix rq->clock synchronization when migrating tasks
|
|
|
|
sched_fork() -- we do task placement in ->task_fork_fair() ensure we
|
|
update_rq_clock() so we work with current time. We leave the vruntime
|
|
in relative state, so the time delay until wake_up_new_task() doesn't
|
|
matter.
|
|
|
|
wake_up_new_task() -- Since task_fork_fair() left p->vruntime in
|
|
relative state we can safely migrate, the activate_task() on the
|
|
remote rq will call update_rq_clock() and causes the clock to be
|
|
synced (enough).
|
|
|
|
Tested-by: Jack Daniel <wanders.thirst@gmail.com>
|
|
Tested-by: Philby John <pjohn@mvista.com>
|
|
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
|
|
LKML-Reference: <1281002322.1923.1708.camel@laptop>
|
|
Signed-off-by: Ingo Molnar <mingo@elte.hu>
|
|
---
|
|
|
|
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
|
|
index 806d1b2..ab661eb 100644
|
|
--- a/kernel/sched_fair.c
|
|
+++ b/kernel/sched_fair.c
|
|
@@ -3752,6 +3752,8 @@ static void task_fork_fair(struct task_struct *p)
|
|
|
|
raw_spin_lock_irqsave(&rq->lock, flags);
|
|
|
|
+ update_rq_clock(rq);
|
|
+
|
|
if (unlikely(task_cpu(p) != this_cpu))
|
|
__set_task_cpu(p, this_cpu);
|
|
|