Message-ID: <1433341448.1495.4.camel@twins>
Subject: Re: [PATCH RESEND] sched: prefer an idle cpu vs an idle sibling for
 BALANCE_WAKE
From: Peter Zijlstra <peterz@infradead.org>
To: Rik van Riel <riel@redhat.com>
Cc: Josef Bacik <jbacik@fb.com>, mingo@redhat.com,
        linux-kernel@vger.kernel.org, umgwanakikbuti@gmail.com,
        morten.rasmussen@arm.com, kernel-team <Kernel-team@fb.com>
Date: Wed, 03 Jun 2015 16:24:08 +0200
In-Reply-To: <556F0B5E.6030805@redhat.com>
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On Wed, 2015-06-03 at 10:12 -0400, Rik van Riel wrote:

> There is a policy vs mechanism thing here. Ingo and Peter
> are worried about the overhead in the mechanism of finding
> an idle CPU.  Your measurements show that the policy of
> finding an idle CPU is the correct one.

For his workload; I'm sure I can find a workload where it hurts.

In fact, I'm fairly sure Mike knows one from the top of his head, seeing
how he's the one playing about trying to shrink that idle search :-)
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