From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760014AbZEML3T (ORCPT ); Wed, 13 May 2009 07:29:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757374AbZEML3A (ORCPT ); Wed, 13 May 2009 07:29:00 -0400 Received: from cmpxchg.org ([85.214.51.133]:41712 "EHLO cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754628AbZEML27 (ORCPT ); Wed, 13 May 2009 07:28:59 -0400 Date: Wed, 13 May 2009 13:26:40 +0200 From: Johannes Weiner To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , Rik van Riel , Christoph Lameter Subject: Re: [PATCH 3/4] vmscan: zone_reclaim use may_swap Message-ID: <20090513112640.GC2254@cmpxchg.org> References: <20090513120155.5879.A69D9226@jp.fujitsu.com> <20090513120651.5882.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090513120651.5882.A69D9226@jp.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2009 at 12:07:30PM +0900, KOSAKI Motohiro wrote: > Subject: [PATCH] vmscan: zone_reclaim use may_swap > > Documentation/sysctl/vm.txt says > > zone_reclaim_mode: > > Zone_reclaim_mode allows someone to set more or less aggressive approaches to > reclaim memory when a zone runs out of memory. If it is set to zero then no > zone reclaim occurs. Allocations will be satisfied from other zones / nodes > in the system. > > This is value ORed together of > > 1 = Zone reclaim on > 2 = Zone reclaim writes dirty pages out > 4 = Zone reclaim swaps pages > > > So, "(zone_reclaim_mode & RECLAIM_SWAP) == 0" mean we don't want to reclaim > swap-backed pages. not mapped file. > > Thus, may_swap is better than may_unmap. > > > Signed-off-by: KOSAKI Motohiro > Cc: Christoph Lameter > Cc: Rik van Riel Reviewed-by: Johannes Weiner