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

[Lei Wen]

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...

Thanks,
Lei
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/