From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754854Ab0IWLot (ORCPT ); Thu, 23 Sep 2010 07:44:49 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:35638 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753156Ab0IWLos (ORCPT ); Thu, 23 Sep 2010 07:44:48 -0400 Date: Thu, 23 Sep 2010 17:14:42 +0530 From: Balbir Singh To: KOSAKI Motohiro Cc: robm@fastmail.fm, linux-kernel@vger.kernel.org, Bron Gondwana , linux-mm , Christoph Lameter , Mel Gorman Subject: Re: Default zone_reclaim_mode = 1 on NUMA kernel is bad for file/email/web servers Message-ID: <20100923114442.GK3952@balbir.in.ibm.com> Reply-To: balbir@linux.vnet.ibm.com References: <1284349152.15254.1394658481@webmail.messagingengine.com> <20100916184240.3BC9.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20100916184240.3BC9.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-12-10) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * KOSAKI Motohiro [2010-09-16 19:01:32]: > + if (!(zone_reclaim_mode & RECLAIM_CACHE) && > + (gfp_mask & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK) { > + inc_zone_state(zone, NR_ZONE_CACHE_AVOID); > + goto try_next_zone; > + } > + Interesting approach, so for page cache related applications we expect RECLAIM_CACHE to be set and hence zone_reclaim to occur. I have another variation, a new gfp flag called __GFP_FREE_CACHE. You can find the patches at http://lwn.net/Articles/391293/ http://article.gmane.org/gmane.linux.kernel.mm/49155 -- Three Cheers, Balbir