Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932395Ab2F1BHI (ORCPT ); Wed, 27 Jun 2012 21:07:08 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:37711 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756901Ab2F1BHB (ORCPT ); Wed, 27 Jun 2012 21:07:01 -0400 Date: Wed, 27 Jun 2012 18:06:59 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Minchan Kim cc: Rik van Riel , Jim Schutt , Andrew Morton , Mel Gorman , KAMEZAWA Hiroyuki , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "ceph-devel@vger.kernel.org" Subject: Re: excessive CPU utilization by isolate_freepages? In-Reply-To: <4FEBAC42.3030800@kernel.org> Message-ID: References: <4FEB8237.6030402@sandia.gov> <4FEB9E73.5040709@kernel.org> <4FEBA520.4030205@redhat.com> <4FEBAC42.3030800@kernel.org> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 906 Lines: 23 On Thu, 28 Jun 2012, Minchan Kim wrote: > >>> > > https://lkml.org/lkml/2012/6/21/30 > >> > > > Not sure if Jim is using memcg; if not, then this won't be helpful. > > > > > It doesn't related to memcg. > if compaction_alloc can't find suitable migration target, it returns NULL. > Then, migrate_pages should be exit. > If isolate_freepages() is going to fail, then this zone should have been skipped when checking for compaction_suitable(). In Jim's perf output, compaction_suitable() returns COMPACT_CONTINUE for a transparent hugepage. Why is zone_watermark_ok(zone, 0 low_wmark + 1024, 0, 0) succeeding if isolate_freepages() is going to fail? -- 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/