Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755689Ab1DKVaJ (ORCPT ); Mon, 11 Apr 2011 17:30:09 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:60432 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755170Ab1DKVaI (ORCPT ); Mon, 11 Apr 2011 17:30:08 -0400 Subject: Re: [PATCH resend^2] mm: increase RECLAIM_DISTANCE to 30 From: Dave Hansen To: KOSAKI Motohiro Cc: LKML , linux-mm , Andrew Morton , Christoph Lameter , David Rientjes , KAMEZAWA Hiroyuki , Chris McDermott In-Reply-To: <20110411172004.0361.A69D9226@jp.fujitsu.com> References: <20110411172004.0361.A69D9226@jp.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1" Date: Mon, 11 Apr 2011 14:29:31 -0700 Message-ID: <1302557371.7286.16607.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1281 Lines: 29 On Mon, 2011-04-11 at 17:19 +0900, KOSAKI Motohiro wrote: > This patch raise zone_reclaim_mode threshold to 30. 30 don't have > specific meaning. but 20 mean one-hop QPI/Hypertransport and such > relatively cheap 2-4 socket machine are often used for tradiotional > server as above. The intention is, their machine don't use > zone_reclaim_mode. I know specifically of pieces of x86 hardware that set the information in the BIOS to '21' *specifically* so they'll get the zone_reclaim_mode behavior which that implies. They've done performance testing and run very large and scary benchmarks to make sure that they _want_ this turned on. What this means for them is that they'll probably be de-optimized, at least on newer versions of the kernel. If you want to do this for particular systems, maybe _that_'s what we should do. Have a list of specific configurations that need the defaults overridden either because they're buggy, or they have an unusual hardware configuration not really reflected in the distance table. -- Dave -- 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/