linux-kernel - Re: [patch] sched: add the other missing clock update to migrate

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: Windows password security audit tool. GUI, reports in PDF.

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

Date:	Sun, 22 Nov 2009 17:58:43 +0100
From:	Mike Galbraith <efault@....de>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [patch] sched: add the other missing clock update to
 migrate_task()

On Sun, 2009-11-22 at 14:16 +0100, Peter Zijlstra wrote:

> We should make double_rq_lock() and double_lock_balance() behave
> equivalent wrt update_rq_clock().
> 
> Current, depending on CONFIG_PREEMPT, double_lock_balance() already
> updates both rq clocks.

Hm, right.  Better plan.  We can save an update in the wakeup path for
the tasks racing for the wakeup case too.  If the call is really a
lock/unlock go away, we don't need to bother.  Shave a ns or so.

	-Mike

--
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/