From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754442Ab1KUJSy (ORCPT ); Mon, 21 Nov 2011 04:18:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:5736 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752591Ab1KUJSx (ORCPT ); Mon, 21 Nov 2011 04:18:53 -0500 Date: Mon, 21 Nov 2011 10:18:18 +0100 From: Johannes Weiner To: Dave Jones , Mel Gorman , Andrea Arcangeli , Jan Kara , Andy Isaacson , linux-kernel@vger.kernel.org, linux-mm@vger.kernel.org, kernel-team@fedoraproject.org Subject: Re: long sleep_on_page delays writing to slow storage Message-ID: <20111121091818.GC1771@redhat.com> References: <20111107045928.GK8927@hexapodia.org> <20111109170027.GB7495@quack.suse.cz> <20111109175201.GB3083@suse.de> <20111109180646.GM5075@redhat.com> <20111110093442.GG3153@redhat.com> <20111114184717.GA7006@redhat.com> <20111115101313.GA28350@suse.de> <20111117194719.GA23213@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111117194719.GA23213@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 17, 2011 at 02:47:20PM -0500, Dave Jones wrote: > On Tue, Nov 15, 2011 at 10:13:13AM +0000, Mel Gorman wrote: > > > If they are still experiencing major stalls, I have an experimental > > script that may be able to capture stack traces of processes stalled > > for more than 1 second. I've had some success with it locally so > > maybe they could try it out to identify if it's THP or something else. > > I'm not sure if it's the same problem, but I'd be interested in trying > that script. > > When I build a kernel on my laptop, when it gets to the final link stage, > and there's a ton of IO, my entire X session wedges for a few seconds. > This may be unrelated, because this is on an SSD, which shouldn't suffer > from the slow IO of the USB devices mentioned in this thread. > > (This is even with that patch applied btw, perhaps adding further fuel to > the idea that it's unrelated). We still have the problem that individual zones may fill up unproportionately with dirty pages and reclaim can take a while to make progress in such zones. Would you mind trying the per-zone dirty limits patch set? You can find it here: http://cmpxchg.org/~hannes/kernel/mm-per-zone-dirty-limits/ git am pzd.mbox should work on 3.2-rc1.