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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 30 Dec 2013 12:56:49 +0800
From:	Lei Wen <adrian.wenl@...il.com>
To:	Mike Galbraith <bitbucket@...ine.de>
Cc:	linux-kernel@...r.kernel.org,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>, leiwen@...vell.com
Subject: Re: [RFC] sched: update rq clock when only get preempt

Hi Mike,

On Mon, Dec 30, 2013 at 12:08 PM, Mike Galbraith <bitbucket@...ine.de> 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@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/