Commit-ID: 861d034ee814917a83bd5de4b26e3b8336ddeeb8 Gitweb: http://git.kernel.org/tip/861d034ee814917a83bd5de4b26e3b8336ddeeb8 Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx> AuthorDate: Thu, 19 Aug 2010 13:31:43 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Fri, 20 Aug 2010 14:59:01 +0200 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@xxxxxxxxx> Tested-by: Philby John <pjohn@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> LKML-Reference: <1281002322.1923.1708.camel@laptop> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- 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 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); -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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