From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753355AbbBESpq (ORCPT ); Thu, 5 Feb 2015 13:45:46 -0500 Received: from e37.co.us.ibm.com ([32.97.110.158]:58956 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753097AbbBESpo (ORCPT ); Thu, 5 Feb 2015 13:45:44 -0500 Date: Thu, 5 Feb 2015 10:45:37 -0800 From: "Paul E. McKenney" To: Dave Hansen Cc: Steven Rostedt , sedat.dilek@gmail.com, "Rafael J. Wysocki" , "Rafael J. Wysocki" , linux-next , LKML , Stephen Rothwell , Kristen Carlson Accardi , "H. Peter Anvin" , Rik van Riel , Mel Gorman Subject: Re: linux-next: Tree for Feb 4 Message-ID: <20150205184537.GJ5370@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20150205005716.GS5370@linux.vnet.ibm.com> <20150205015144.GT5370@linux.vnet.ibm.com> <54D3186F.7030500@sr71.net> <20150205130343.6ac0eda9@gandalf.local.home> <20150205130802.289a8be0@gandalf.local.home> <54D3B253.3050000@sr71.net> <20150205183412.GI5370@linux.vnet.ibm.com> <54D3B7F5.9070209@sr71.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54D3B7F5.9070209@sr71.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15020518-0025-0000-0000-00000855C6F9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 05, 2015 at 10:35:33AM -0800, Dave Hansen wrote: > On 02/05/2015 10:34 AM, Paul E. McKenney wrote: > >> > Did I actually need to be > >> > onlining/offlining CPUs to hit the splat that Sedat was reporting? > > Yep, you do need to offline at least one CPU to hit that splat. > > Heh, do we need a debugging mode that will randomly offline/online CPUs? :) For that, kernel/rcu/rcutorture.c and kernel/locking/locktorture.c are your friends. ;-) The problem is that I only run RCU-relevant combinations of Kconfigs, which means that I missed the ones that Sedat used to find this problem. So I guess it is a good thing that others run -next testing. Thanx, Paul