Re: [RFC] sched: update rq clock when only get preempt

From: Lei Wen
Date: Sun Dec 29 2013 - 23:57:18 EST

Hi Mike,

On Mon, Dec 30, 2013 at 12:08 PM, Mike Galbraith <bitbucket@xxxxxxxxx> wrote:
> On Mon, 2013-12-30 at 11:14 +0800, Lei Wen wrote:
>> Since we would update rq clock at task enqueue/dequeue, or schedule
>> tick. If we don't update the rq clock when our previous task get
>> preempted, our new started task would get a relative stale rq clock
>> which is updated during the previous task enqueue, or the last schedule
>> clock update.
>> @@ -2555,6 +2556,8 @@ need_resched:
>> idle_balance(cpu, rq);
>> put_prev_task(rq, prev);
>> + if (update)
>> + update_rq_clock(rq);
> If prev remained enqueued, the clock was updated by put_prev_task().

It indeed like that, sorry for the noise...

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