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Date: Mon, 23 Jun 2014 18:22:34 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>, Ingo Molnar <mingo@elte.hu>,
        Andi Kleen <andi@firstfloor.org>,
        Michel Lespinasse <walken@google.com>, Rik van Riel <riel@redhat.com>,
        Peter Hurley <peter@hurleysoftware.com>, Jason Low <jason.low2@hp.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
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> So I don't get why we can't do the below; I think Jason tried to ask the
> same...

The important part for performance is to minimize the cache line transfers. Your
unconditional variant would cause more dirty cache lines than Tim's,
right?

-Andi