Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985Ab1FHKHY (ORCPT ); Wed, 8 Jun 2011 06:07:24 -0400 Received: from cantor2.suse.de ([195.135.220.15]:53910 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752821Ab1FHKHX (ORCPT ); Wed, 8 Jun 2011 06:07:23 -0400 Date: Wed, 8 Jun 2011 12:07:20 +0200 From: Michal Hocko To: Mel Gorman Cc: Andrew Morton , Andrea Arcangeli , Minchan Kim , Thomas Sattler , Ury Stankevich , Andi Kleen , linux-mm , linux-kernel Subject: Re: [PATCH 3/4] mm: memory-failure: Fix isolated page count during memory failure Message-ID: <20110608100720.GF6742@tiehlicka.suse.cz> References: <1307459225-4481-1-git-send-email-mgorman@suse.de> <1307459225-4481-4-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1307459225-4481-4-git-send-email-mgorman@suse.de> 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: 1635 Lines: 43 On Tue 07-06-11 16:07:04, Mel Gorman wrote: > From: Minchan Kim > > From: Minchan Kim > > Pages isolated for migration are accounted with the vmstat counters > NR_ISOLATE_[ANON|FILE]. Callers of migrate_pages() are expected to > increment these counters when pages are isolated from the LRU. Once > the pages have been migrated, they are put back on the LRU or freed > and the isolated count is decremented. Aren't we missing this in compact_zone as well? AFAICS there is no accounting done after we isolate pages from LRU? Or am I missing something? > > Memory failure is not properly accounting for pages it isolates > causing the NR_ISOLATED counters to be negative. On SMP builds, > this goes unnoticed as negative counters are treated as 0 due to > expected per-cpu drift. On UP builds, the counter is treated by > too_many_isolated() as a large value causing processes to enter D > state during page reclaim or compaction. This patch accounts for > pages isolated by memory failure correctly. > > [mgorman@suse.de: Updated changelog] > Signed-off-by: Minchan Kim > Signed-off-by: Mel Gorman > Reviewed-by: Andrea Arcangeli Reviewed-by: Michal Hocko -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- 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/