From: Peter Zijlstra <peterz@infradead.org>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Jason Low <jason.low2@hp.com>, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Len Brown <len.brown@intel.com>, Russ Anderson <rja@sgi.com>,
Dimitri Sivanich <sivanich@sgi.com>, Hedi Berriche <hedi@sgi.com>,
Andi Kleen <andi@firstfloor.org>,
Michel Lespinasse <walken@google.com>,
Rik van Riel <riel@redhat.com>,
Peter Hurley <peter@hurleysoftware.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] sched: Reduce the rate of needless idle load balancing
Date: Wed, 21 May 2014 08:38:26 +0200 [thread overview]
Message-ID: <20140521063826.GC30445@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1400621967.2970.280.camel@schen9-DESK>
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On Tue, May 20, 2014 at 02:39:27PM -0700, Tim Chen wrote:
> From: Tim Chen <tim.c.chen@linux.intel.com>
> Subject: [PATCH v2] sched: Reduce the rate of needless idle load balancing
>
>
> The current no_hz idle load balancer do load balancing for *all* idle cpus,
> even though the time due to load balance for a particular
> idle cpu could be still a while in the future. This introduces a much
> higher load balancing rate than what is necessary. The patch
> changes the behavior by only doing idle load balancing on
> behalf of an idle cpu only when it is due for load balancing.
>
> On SGI's systems with over 3000 cores, the cpu responsible for idle balancing
> got overwhelmed with idle balancing, and introduces a lot of OS noise
> to workloads. This patch fixes the issue.
>
> Acked-by: Russ Anderson <rja@sgi.com>
> Reviewed-by: Rik van Riel <riel@redhat.com>
> Reviewed-by: Jason Low <jason.low2@hp.com>
> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
> ---
Thanks!
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next prev parent reply other threads:[~2014-05-21 6:38 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-20 20:17 [PATCH] sched: Reduce the rate of needless idle load balancing Tim Chen
2014-05-20 20:51 ` Jason Low
2014-05-20 20:58 ` Rik van Riel
2014-05-20 20:59 ` Tim Chen
2014-05-20 21:04 ` Tim Chen
2014-05-21 1:15 ` Joe Perches
2014-05-21 16:37 ` Tim Chen
2014-05-21 18:26 ` Davidlohr Bueso
2014-05-21 18:49 ` Tim Chen
2014-05-20 21:09 ` Jason Low
2014-05-20 21:12 ` Tim Chen
2014-05-20 21:39 ` Tim Chen
2014-05-21 6:38 ` Peter Zijlstra [this message]
2014-06-05 14:34 ` [tip:sched/core] sched/balancing: " tip-bot for Tim Chen
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