diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2010-08-19 13:31:43 +0200 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2011-01-06 18:07:51 -0500 |
| commit | 64c0d770b67e0bdab7addafd1e19cdcd94be87e3 (patch) | |
| tree | 8977c3b06d76d6c8d300337459a76d5bedbd4766 /kernel | |
| parent | d9f7ec9b3727555ba55ad14bddb056468fc7e122 (diff) | |
sched: Fix rq->clock synchronization when migrating tasks
commit 861d034ee814917a83bd5de4b26e3b8336ddeeb8 upstream.
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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched_fair.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 684e173c00f4..461d312d54db 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -3588,6 +3588,8 @@ 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); |