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Date: Fri, 4 May 2012 08:04:11 -0700
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Cc: Josh Boyer <jwboyer@redhat.com>, linux-kernel@vger.kernel.org,
        kernel-team@fedoraproject.org
Subject: Re: RCU related performance regression in 3.3
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On Fri, May 04, 2012 at 04:42:54PM +0200, Pascal Chapperon wrote:
> Le 01/05/2012 17:45, Paul E. McKenney a écrit :
> 
> >Here is my RCU_FAST_NO_HZ patch stack on top of v3.4-rc4.
> >
> >Or you can pull branch fnh.2012.05.01a from:
> >
> >	git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> >
> >							Thanx, Paul
> >
> I applied your global patch on top of v3.4-rc4. But the slowdown is
> worse than before : boot sequence took 80s instead 20-30s (12s for
> initramfs instead of 2s).
> 
> I'll send you rcu tracing log in a second mail.

Hmmm...  Well, I guess I am glad that I finally did something that
had an effect, but I sure wish that the effect had been in the other
direction!

Just to make sure I understand: the difference between the 20-30s and
the 80s is exactly the patch I sent you?

							Thanx, Paul