Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932564Ab2K1XyT (ORCPT ); Wed, 28 Nov 2012 18:54:19 -0500 Received: from cantor2.suse.de ([195.135.220.15]:44070 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754215Ab2K1XyS (ORCPT ); Wed, 28 Nov 2012 18:54:18 -0500 Date: Wed, 28 Nov 2012 23:54:12 +0000 From: Mel Gorman To: Andrew Morton Cc: Linus Torvalds , Johannes Weiner , Rik van Riel , George Spelvin , Johannes Hirte , Tomas Racek , Jan Kara , Dave Hansen , Josh Boyer , Valdis Kletnieks , Jiri Slaby , Thorsten Leemhuis , Zdenek Kabelac , Bruno Wolff III , linux-mm , Linux Kernel Mailing List Subject: Re: kswapd craziness in 3.7 Message-ID: <20121128235412.GW8218@suse.de> References: <1354049315-12874-1-git-send-email-hannes@cmpxchg.org> <50B52DC4.5000109@redhat.com> <20121127214928.GA20253@cmpxchg.org> <50B5387C.1030005@redhat.com> <20121127222637.GG2301@cmpxchg.org> <20121128101359.GT8218@suse.de> <20121128145215.d23aeb1b.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20121128145215.d23aeb1b.akpm@linux-foundation.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3286 Lines: 68 On Wed, Nov 28, 2012 at 02:52:15PM -0800, Andrew Morton wrote: > On Wed, 28 Nov 2012 10:13:59 +0000 > Mel Gorman wrote: > > > Based on the reports I've seen I expect the following to work for 3.7 > > > > Keep > > 96710098 mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" > > ef6c5be6 fix incorrect NR_FREE_PAGES accounting (appears like memory leak) > > > > Revert > > 82b212f4 Revert "mm: remove __GFP_NO_KSWAPD" > > > > Merge > > mm: vmscan: fix kswapd endless loop on higher order allocation > > mm: Avoid waking kswapd for THP allocations when compaction is deferred or contended > > "mm: Avoid waking kswapd for THP ..." is marked "I have not tested it > myself" and when Zdenek tested it he hit an unexplained oom. > I thought Zdenek was testing with __GFP_NO_KSWAPD when he hit that OOM. Further, when he hit that OOM, it looked like a genuine OOM. He had no swap configured and inactive/active file pages were very low. Finally, the free pages for Normal looked off and could also have been affected by the accounting bug. I'm looking at https://lkml.org/lkml/2012/11/18/132 here. Are you thinking of something else? I have not tested with the patch admittedly but Thorsten has and seemed to be ok with it https://lkml.org/lkml/2012/11/23/276. > > Johannes' patch should remove the necessity for __GFP_NO_KSWAPD revert but I > > think we should also avoid waking kswapd for THP allocations if compaction > > is deferred. Johannes' patch might mean that kswapd goes quickly go back > > to sleep but it's still busy work. > > > > 3.6 is still known to be screwed in terms of THP because of the amount of > > time it can spend in compaction after lumpy reclaim was removed. This is > > my old list of patches I felt needed to be backported after 3.7 came out. > > They are not tagged -stable, I'll be sending it to Greg manually. > > > > e64c523 mm: compaction: abort compaction loop if lock is contended or run too long > > 3cc668f mm: compaction: move fatal signal check out of compact_checklock_irqsave > > 661c4cb mm: compaction: Update try_to_compact_pages()kerneldoc comment > > 2a1402a mm: compaction: acquire the zone->lru_lock as late as possible > > f40d1e4 mm: compaction: acquire the zone->lock as late as possible > > 753341a revert "mm: have order > 0 compaction start off where it left" > > bb13ffe mm: compaction: cache if a pageblock was scanned and no pages were isolated > > c89511a mm: compaction: Restart compaction from near where it left off > > 6299702 mm: compaction: clear PG_migrate_skip based on compaction and reclaim activity > > 0db63d7 mm: compaction: correct the nr_strict va isolated check for CMA > > > > Only Johannes' patch needs to be added to this list. kswapd is not woken > > for THP in 3.6 but as it calls compaction for other high-order allocations > > it still makes sense. > > Please identify "Johannes' patch"? mm: vmscan: fix kswapd endless loop on higher order allocation -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/