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Date: Tue, 2 Dec 2014 15:30:44 -0500
From: Dave Jones <davej@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: =?iso-8859-1?Q?D=E2niel?= Fraga <fragabr@gmail.com>,
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        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: frequent lockups in 3.18rc4
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On Mon, Dec 01, 2014 at 12:36:34PM -0800, Linus Torvalds wrote:
 > On Mon, Dec 1, 2014 at 12:28 PM, Dâniel Fraga <fragabr@gmail.com> wrote:
 > >
 > >         Hi Paul. Please, I'd like the patch, because without
 > > preemption, I'm unable to trigger this bug.
 > 
 > Ok, that's already interesting information. And yes, it would probably
 > be interesting to see if CONFIG_PREEMPT=y but !CONFIG_TREE_PREEMPT_RCU
 > then solves it too, to narrow it down to one but not the other..

That combination doesn't seem possible. TREE_PREEMPT_RCU is the only
possible choice if PREEMPT=y

	Dave