Date: Tue, 8 May 2012 10:34:25 -0500 (CDT)
From: Christoph Lameter <cl@linux.com>
To: Gilad Ben-Yossef <gilad@benyossef.com>
cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>, linux-kernel@vger.kernel.org,
        Thomas Gleixner <tglx@linutronix.de>, Tejun Heo <tj@kernel.org>,
        John Stultz <johnstul@us.ibm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Mel Gorman <mel@csn.ul.ie>, Mike Frysinger <vapier@gentoo.org>,
        David Rientjes <rientjes@google.com>, Hugh Dickins <hughd@google.com>,
        Minchan Kim <minchan.kim@gmail.com>,
        Konstantin Khlebnikov <khlebnikov@openvz.org>,
        Chris Metcalf <cmetcalf@tilera.com>,
        Hakan Akkan <hakanakkan@gmail.com>,
        Max Krasnyansky <maxk@qualcomm.com>,
        Frederic Weisbecker <fweisbec@gmail.com>, linux-mm@kvack.org
Subject: Re: [PATCH v1 5/6] mm: make vmstat_update periodic run conditional
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On Tue, 8 May 2012, Gilad Ben-Yossef wrote:

> > But this would still mean that the vmstat update thread would run on an
> > arbitrary cpu. If I have a sacrificial lamb processor for OS processing
> > then I would expect the vmstat update thread to stick to that processor
> > and avoid to run on the other processor that I would like to be as free
> > from OS noise as possible.
> >
>
> OK, what about -
>
> - We pick a scapegoat cpu (the first to come up gets the job).
> - We add a knob to let user designate another cpu for the job.
> - If scapegoat cpus goes offline, the cpu processing the off lining is
> the new scapegoat.
>
> Does this makes better sense?

Sounds good. The first that comes up. If the cpu is isolated then the
first non isolated cpu is picked.

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