From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756263Ab3G3R5l (ORCPT ); Tue, 30 Jul 2013 13:57:41 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:58947 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753051Ab3G3R5k (ORCPT ); Tue, 30 Jul 2013 13:57:40 -0400 Date: Tue, 30 Jul 2013 10:57:18 -0700 From: "Paul E. McKenney" To: Dave Jones , Linux Kernel , linux-mm@kvack.org, kosaki.motohiro@gmail.com, walken@google.com, akpm@linux-foundation.org, torvalds@linux-foundation.org Subject: Re: mlockall triggred rcu_preempt stall. Message-ID: <20130730175718.GA8957@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20130719145323.GA1903@redhat.com> <20130719221538.GH21367@linux.vnet.ibm.com> <20130720003212.GA31308@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130720003212.GA31308@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13073017-7408-0000-0000-00001278C75B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 19, 2013 at 08:32:12PM -0400, Dave Jones wrote: > On Fri, Jul 19, 2013 at 03:15:39PM -0700, Paul E. McKenney wrote: > > On Fri, Jul 19, 2013 at 10:53:23AM -0400, Dave Jones wrote: > > > My fuzz tester keeps hitting this. Every instance shows the non-irq stack > > > came in from mlockall. I'm only seeing this on one box, but that has more > > > ram (8gb) than my other machines, which might explain it. > > > > Are you building CONFIG_PREEMPT=n? I don't see any preemption points in > > do_mlockall(), so a range containing enough vmas might well stall the > > CPU in that case. > > That was with full preempt. > > > Does the patch below help? If so, we probably need others, but let's > > first see if this one helps. ;-) > > I'll try it on Monday. Any news? If I don't hear otherwise, I will assume that the patch did not help, and will therefore drop it. Thanx, Paul