From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx199.postini.com [74.125.245.199]) by kanga.kvack.org (Postfix) with SMTP id 564646B005A for ; Wed, 27 Jun 2012 21:07:02 -0400 (EDT) Received: by pbbrp2 with SMTP id rp2so2792018pbb.14 for ; Wed, 27 Jun 2012 18:07:01 -0700 (PDT) Date: Wed, 27 Jun 2012 18:06:59 -0700 (PDT) From: David Rientjes 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> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: 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" 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, 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