From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx138.postini.com [74.125.245.138]) by kanga.kvack.org (Postfix) with SMTP id 4827D6B0031 for ; Fri, 19 Jul 2013 20:32:23 -0400 (EDT) Date: Fri, 19 Jul 2013 20:32:12 -0400 From: Dave Jones Subject: Re: mlockall triggred rcu_preempt stall. Message-ID: <20130720003212.GA31308@redhat.com> References: <20130719145323.GA1903@redhat.com> <20130719221538.GH21367@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130719221538.GH21367@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Paul E. McKenney" Cc: Linux Kernel , linux-mm@kvack.org, kosaki.motohiro@gmail.com, walken@google.com, akpm@linux-foundation.org, torvalds@linux-foundation.org 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. Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org