From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: mingo@elte.hu, rusty@rustcorp.com.au, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] stop_machine: disable preempt in stop machine path
Date: Thu, 17 Sep 2009 09:23:24 +0800 [thread overview]
Message-ID: <4AB18F8C.1060104@cn.fujitsu.com> (raw)
In-Reply-To: <20090916160358.7faadb5f.akpm@linux-foundation.org>
Andrew Morton wrote:
> On Wed, 16 Sep 2009 15:26:54 +0800
> Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> wrote:
>
>> We can disable preempt in stop_cpu(), It can reduce the cpu's waiting time
>> and make stop_machine path faster.
>>
>
> "it can"? But does it? Are there any measurements or observations to
> back this up?
>
> The kstop threads are already created with create_rt_workqueue() (which
> has super-secret undocumented semantics which I have cleverly
> discovered mean "use SCHED_FIFO").
>
Ah, indeed, please ignore this mail, sorry for bother you all.
Thanks,
Xiao
> So we won't be getting preempted here anyway?
>
>
next prev parent reply other threads:[~2009-09-17 1:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-16 7:26 [PATCH] stop_machine: disable preempt in stop machine path Xiao Guangrong
2009-09-16 23:03 ` Andrew Morton
2009-09-17 1:23 ` Xiao Guangrong [this message]
2009-09-22 5:50 ` Rusty Russell
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