Date: Wed, 1 Feb 2012 10:40:45 -0800
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>, linux-kernel@vger.kernel.org,
        Christoph Lameter <cl@linux.com>, Chris Metcalf <cmetcalf@tilera.com>,
        Frederic Weisbecker <fweisbec@gmail.com>, linux-mm@kvack.org,
        Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>,
        Sasha Levin <levinsasha928@gmail.com>, Rik van Riel <riel@redhat.com>,
        Andi Kleen <andi@firstfloor.org>, Mel Gorman <mel@csn.ul.ie>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>, Avi Kivity <avi@redhat.com>,
        Michal Nazarewicz <mina86@mina86.com>,
        Kosaki Motohiro <kosaki.motohiro@gmail.com>,
        Milton Miller <miltonm@bga.com>
Subject: Re: [v7 0/8] Reduce cross CPU IPI interference
Message-ID: <20120201184045.GG2382@linux.vnet.ibm.com>
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On Wed, Feb 01, 2012 at 06:35:22PM +0100, Peter Zijlstra wrote:
> On Sun, 2012-01-29 at 10:25 +0200, Gilad Ben-Yossef wrote:
> > 
> > If this is of interest, I keep a list tracking global IPI and global
> > task schedulers sources in the core kernel here:
> > https://github.com/gby/linux/wiki. 
> 
> You can add synchronize_.*_expedited() to the list, it does its best to
> bash the entire machine in order to try and make RCU grace periods
> happen fast.

I have duly added "Make synchronize_sched_expedited() avoid IPIing idle
CPUs" to http://kernel.org/pub/linux/kernel/people/paulmck/rcutodo.html.

This should not be hard once I have built up some trust in the new
RCU idle-detection code.  It would also automatically apply to
Frederic's dyntick-idle userspace work.

							Thanx, Paul

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