From: Andrew Morton <akpm@linux-foundation.org>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
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: Wed, 16 Sep 2009 16:03:58 -0700 [thread overview]
Message-ID: <20090916160358.7faadb5f.akpm@linux-foundation.org> (raw)
In-Reply-To: <4AB0933E.8020901@cn.fujitsu.com>
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").
So we won't be getting preempted here anyway?
next prev parent reply other threads:[~2009-09-16 23:04 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 [this message]
2009-09-17 1:23 ` Xiao Guangrong
2009-09-22 5:50 ` Rusty Russell
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