From: Peter Zijlstra <peterz@infradead.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
Ingo Molnar <mingo@elte.hu>,
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
Date: Mon, 23 Jun 2014 20:47:57 +0200 [thread overview]
Message-ID: <20140623184757.GG13930@laptop.programming.kicks-ass.net> (raw)
In-Reply-To: <20140623162234.GP5714@two.firstfloor.org>
On Mon, Jun 23, 2014 at 06:22:34PM +0200, Andi Kleen wrote:
> > 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?
Don't think so. We already have the overloaded thing on stack and dirty,
and the only thing it needs is rq->nr_running and we already
unconditionally load that.
next prev parent reply other threads:[~2014-06-23 18:48 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
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 [this message]
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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