From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 04A27900086 for ; Tue, 12 Apr 2011 20:49:11 -0400 (EDT) Received: from d01dlp02.pok.ibm.com (d01dlp02.pok.ibm.com [9.56.224.85]) by e7.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p3D0REYp029988 for ; Tue, 12 Apr 2011 20:27:14 -0400 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 95C9E6E8039 for ; Tue, 12 Apr 2011 20:49:09 -0400 (EDT) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p3D0n90A317800 for ; Tue, 12 Apr 2011 20:49:09 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p3D0n8UU006656 for ; Tue, 12 Apr 2011 21:49:09 -0300 Subject: Re: [PATCH resend^2] mm: increase RECLAIM_DISTANCE to 30 From: Dave Hansen In-Reply-To: References: <20110411172004.0361.A69D9226@jp.fujitsu.com> <1302557371.7286.16607.camel@nimitz> Content-Type: text/plain; charset="ISO-8859-1" Date: Tue, 12 Apr 2011 17:49:06 -0700 Message-ID: <1302655746.8321.4001.camel@nimitz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: KOSAKI Motohiro , LKML , linux-mm , Andrew Morton , Christoph Lameter , KAMEZAWA Hiroyuki , Chris McDermott On Tue, 2011-04-12 at 17:22 -0700, David Rientjes wrote: > On Mon, 11 Apr 2011, Dave Hansen wrote: > 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. > > That doesn't seem like an argument against this patch, it's an improper > configuration unless the remote memory access has a latency of 2.1x that > of a local access between those two nodes. If that's the case, then it's > accurately following the ACPI spec and the VM has made its policy decision > to enable zone_reclaim_mode as a result. Heh, if the kernel broke on every system that didn't follow _some_ spec, it wouldn't boot in very many places. When you have a hammer, everything looks like a nail. When you're a BIOS developer, you start thwacking at the kernel with munged ACPI tables instead of boot options. Folks do this in the real world, and I think if we can't put their names and addresses next to the code that works around this, we might as well put the DMI strings of their hardware. :) -- Dave -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org