From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755491AbYJGQeR (ORCPT ); Tue, 7 Oct 2008 12:34:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753507AbYJGQeF (ORCPT ); Tue, 7 Oct 2008 12:34:05 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:35462 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753423AbYJGQeE (ORCPT ); Tue, 7 Oct 2008 12:34:04 -0400 Date: Tue, 7 Oct 2008 09:34:01 -0700 From: "Paul E. McKenney" To: Andi Kleen Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, rjw@sisk.pl, dipankar@in.ibm.com, tglx@linuxtronix.de Subject: Re: RCU hang on cpu re-hotplug with 2.6.27rc8 Message-ID: <20081007163401.GJ6384@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20081006141220.GA14160@basil.nowhere.org> <20081006232837.GA1157@basil.nowhere.org> <20081007030822.GC6820@linux.vnet.ibm.com> <20081007071544.GC20740@one.firstfloor.org> <20081007152629.GH6384@linux.vnet.ibm.com> <20081007154939.GN20740@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081007154939.GN20740@one.firstfloor.org> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 07, 2008 at 05:49:39PM +0200, Andi Kleen wrote: > > Hmmm... I chased out a number of these when doing rcutree. > > > > This with classic RCU or preemptable RCU? > > classic. > > > Could you please send me your .config file? > > http://halobates.de/defconfig64 Thank you! Hmmm, classic RCU, worked just fine in 2.6.27-rc7 with Thomas's patch. I was doing random onlines and offlines in a loop, with about 3 seconds between each operation continuously for more than ten hours, both x86 and Power. So could you please try 2.6.27-rc7 with Thomas's patch as follows? http://www.rdrop.com/users/paulmck/patches/2.6.27-rc7-tglx-timer-1.patch Failing that, I guess my next step would be to create tracing for classic RCU to help figure out what RCU believes is preventing the grace period from ending. Thanx, Paul