From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with SMTP id 9BF566B0047 for ; Sat, 4 Sep 2010 04:15:17 -0400 (EDT) Date: Sat, 4 Sep 2010 18:14:14 +1000 From: Dave Chinner Subject: Re: [PATCH 3/3] mm: page allocator: Drain per-cpu lists after direct reclaim allocation fails Message-ID: <20100904081414.GF705@dastard> References: <1283504926-2120-1-git-send-email-mel@csn.ul.ie> <1283504926-2120-4-git-send-email-mel@csn.ul.ie> <20100903160026.564fdcc9.akpm@linux-foundation.org> <20100904022545.GD705@dastard> <20100903202101.f937b0bb.akpm@linux-foundation.org> <20100904075840.GE705@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20100904075840.GE705@dastard> Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Mel Gorman , Linux Kernel List , linux-mm@kvack.org, Rik van Riel , Johannes Weiner , Minchan Kim , Christoph Lameter , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Wu Fengguang , David Rientjes List-ID: On Sat, Sep 04, 2010 at 05:58:40PM +1000, Dave Chinner wrote: > On Fri, Sep 03, 2010 at 08:21:01PM -0700, Andrew Morton wrote: > > On Sat, 4 Sep 2010 12:25:45 +1000 Dave Chinner wrote: > > > > > Still, given the improvements in performance from this patchset, > > > I'd say inclusion is a no-braniner.... > > > > OK, thanks. > > > > It'd be interesting to check the IPI frequency with and without - > > /proc/interrupts "CAL" field. Presumably it went down a lot. > > Maybe I suspected you would ask for this. I happened to dump > /proc/interrupts after the livelock run finished, so you're in > luck :) .... > > livelock: 59458 58367 58559 59493 59614 57970 59060 58207 > > So the livelock case tends to indicate roughly 40,000 more IPI > interrupts per CPU occurred. The livelock occurred for close to 5 > minutes, so that's roughly 130 IPIs per second per CPU.... And just to confuse the issue further, I just had a livelock on a vanilla kernel that did *not* cause the CAL counts to increase. Hence it appears that the IPI storms are not the cause of the livelocks D?'m triggering.... Cheers, Dave. -- Dave Chinner david@fromorbit.com -- 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