Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933664AbXFSTVA (ORCPT ); Tue, 19 Jun 2007 15:21:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933264AbXFSTUv (ORCPT ); Tue, 19 Jun 2007 15:20:51 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:60489 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933222AbXFSTUu (ORCPT ); Tue, 19 Jun 2007 15:20:50 -0400 Date: Tue, 19 Jun 2007 12:20:49 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Mel Gorman cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com Subject: Re: [PATCH 5/7] Introduce a means of compacting memory within a zone In-Reply-To: <20070619163611.GD17109@skynet.ie> Message-ID: References: <20070618092821.7790.52015.sendpatchset@skynet.skynet.ie> <20070618093002.7790.68471.sendpatchset@skynet.skynet.ie> <20070619163611.GD17109@skynet.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1346 Lines: 32 On Tue, 19 Jun 2007, Mel Gorman wrote: > When other mechanisms exist, they would be added here. Right now, > isolate_lru_page() is the only one I am aware of. Did you have a look at kmem_cache_vacate in the slab defrag patchset? > > You do not need to check the result of migration? Page migration is a best > > effort that may fail. > You're right. I used to check it for debugging purposes to make sure migration > was actually occuring. It is not unusual still for a fair number of pages > to fail to migrate. migration already uses a retry logic and I shouldn't > be replicating it. > > More importantly, by leaving the pages on the migratelist, I potentially > retry the same migrations over and over again wasting time and effort not > to mention that I keep pages isolated for much longer than necessary and > that could cause stalling problems. I should be calling putback_lru_pages() > when migrate_pages() tells me it failed to migrate pages. No the putback_lru is done for you. > I'll revisit this one. Thanks You could simply ignore it if you do not care if its migrated or not. - 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/