From: Jason Low <jason.low2@hp.com>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Andi Kleen <andi@firstfloor.org>,
Michel Lespinasse <walken@google.com>,
Rik van Riel <riel@redhat.com>,
Peter Hurley <peter@hurleysoftware.com>,
Davidlohr Bueson <davidlohr@hp.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] sched: Fast idling of CPU when system is partially loaded
Date: Sun, 22 Jun 2014 21:33:08 -0700 [thread overview]
Message-ID: <1403497988.2377.21.camel@j-VirtualBox> (raw)
In-Reply-To: <1402948127.2970.578.camel@schen9-DESK>
On Mon, 2014-06-16 at 12:48 -0700, Tim Chen wrote:
> Thanks to the review from Jason and Peter. I've moved the check
> of whether load balance is required into fair.c's idle_balance.
>
> When a system is lightly loaded (i.e. no more than 1 job per cpu),
> attempt to pull job to a cpu before putting it to idle is unnecessary and
> can be skipped. This patch adds an indicator so the scheduler can know
> when there's no more than 1 active job is on any CPU in the system to
> skip needless job pulls.
> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: Jason Low <jason.low2@hp.com>
This change would address one of the main issues I've also been seeing
on my test machines with idle_balance where most of the
find_busiest_group overhead is not useful due to that issue with no
tasks to move.
next prev parent reply other threads:[~2014-06-23 4:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-16 19:48 [PATCH v2] sched: Fast idling of CPU when system is partially loaded Tim Chen
2014-06-23 4:33 ` Jason Low [this message]
2014-06-23 12:52 ` Peter Zijlstra
2014-06-23 16:22 ` Andi Kleen
2014-06-23 16:44 ` Jason Low
2014-06-23 17:01 ` Tim Chen
2014-06-23 18:47 ` Peter Zijlstra
2014-06-23 16:40 ` Tim Chen
2014-06-23 18:50 ` Peter Zijlstra
2014-06-23 18:59 ` Tim Chen
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