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From: Ken Chen <kenchen@google.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Mike Galbraith <efault@gmx.de>
Subject: Re: [patch] restore sched_exec load balance heuristics
Date: Thu, 6 Nov 2008 12:32:55 -0800	[thread overview]
Message-ID: <b040c32a0811061232j49a40ce8md32ff5e614441e38@mail.gmail.com> (raw)
In-Reply-To: <20081106200746.GA3578@elte.hu>

On Thu, Nov 6, 2008 at 12:07 PM, Ingo Molnar <mingo@elte.hu> wrote:
> ok, this should be solved - but rather at the level of
> sched_balance_self(): it should never migrate this task over to
> another cpu, it should take away this task's load from the current
> CPU's load when considering migration.

There are two callers to sched_balance_self().  In the sched_fork
path, sched_balance_self will balance the newly forked task.  I think
it is OK to bounce a newly forked task to another CPU since current
CPU will be busy when fork returns in the parent process.

And if sched_balance_self() needs to different between fork / exec
load balance, it has to check a flag from function argument, which I
think it is better to just short circuit in sched_exec() directly.

- Ken

  reply	other threads:[~2008-11-06 20:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-06 19:40 [patch] restore sched_exec load balance heuristics Ken Chen
2008-11-06 20:07 ` Ingo Molnar
2008-11-06 20:32   ` Ken Chen [this message]
2008-11-06 20:38     ` Ingo Molnar
2008-11-06 20:49     ` Chris Friesen
2008-11-10  8:50   ` Peter Zijlstra
2008-11-10  9:29     ` Ingo Molnar
2008-11-10 12:54       ` Peter Zijlstra

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