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From: Mike Galbraith <bitbucket@online.de>
To: Lei Wen <leiwen@marvell.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	mingo@redhat.com, preeti.lkml@gmail.com,
	daniel.lezcano@linaro.org, viresh.kumar@linaro.org,
	xjian@marvell.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] sched: keep quiescent cpu out of idle balance loop
Date: Fri, 21 Feb 2014 10:41:55 +0100	[thread overview]
Message-ID: <1392975715.5451.118.camel@marge.simpson.net> (raw)
In-Reply-To: <1392974108-28778-1-git-send-email-leiwen@marvell.com>

On Fri, 2014-02-21 at 17:15 +0800, Lei Wen wrote:

> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 235cfa7..af30b6a 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6883,6 +6883,14 @@ void nohz_balance_enter_idle(int cpu)
>  	if (!cpu_active(cpu))
>  		return;
>  
> +	/*
> +	 * If this cpu is isolated, its rq's sd member would becomes NULL.
> +	 * Base on this observation, we could exclude this cpu from nohz
> +	 * idle balance, so that it would not be disturbed.
> +	 */
> +	if (!this_rq()->sd)
> +		return;
> +
>  	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
>  		return;

What about nohz_balance_exit_idle()?

I think Peter queued a patchlet to tell nohz balancing to go away.

-Mike


  reply	other threads:[~2014-02-21  9:42 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-19  5:20 [PATCH] sched: keep quiescent cpu out of idle balance loop Lei Wen
2014-02-19  9:04 ` Peter Zijlstra
2014-02-20  2:42   ` Lei Wen
2014-02-20  8:50     ` Peter Zijlstra
2014-02-20  9:15       ` Lei Wen
2014-02-20  9:17       ` Lei Wen
2014-02-20 12:04         ` Peter Zijlstra
2014-02-20 12:23         ` Peter Zijlstra
2014-02-21  2:23           ` [PATCH v2] " Lei Wen
2014-02-21  5:51             ` Mike Galbraith
2014-02-21  7:28               ` Lei Wen
2014-02-21  8:34                 ` Mike Galbraith
2014-02-21  9:15                   ` [PATCH v3] " Lei Wen
2014-02-21  9:41                     ` Mike Galbraith [this message]
2014-02-21  9:15                   ` [PATCH v2] " Mike Galbraith

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