Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752072AbZIUSHf (ORCPT ); Mon, 21 Sep 2009 14:07:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751664AbZIUSHe (ORCPT ); Mon, 21 Sep 2009 14:07:34 -0400 Received: from gir.skynet.ie ([193.1.99.77]:58818 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751529AbZIUSHe (ORCPT ); Mon, 21 Sep 2009 14:07:34 -0400 Date: Mon, 21 Sep 2009 19:07:39 +0100 From: Mel Gorman To: Christoph Lameter Cc: Nick Piggin , Pekka Enberg , heiko.carstens@de.ibm.com, sachinp@in.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Tejun Heo , Benjamin Herrenschmidt Subject: Re: [RFC PATCH 0/3] Fix SLQB on memoryless configurations V2 Message-ID: <20090921180739.GT12726@csn.ul.ie> References: <1253549426-917-1-git-send-email-mel@csn.ul.ie> <20090921174656.GS12726@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1514 Lines: 38 On Mon, Sep 21, 2009 at 01:54:12PM -0400, Christoph Lameter wrote: > Lets just keep SLQB back until the basic issues with memoryless nodes are > resolved. It's not even super-clear that the memoryless nodes issues are entirely related to SLQB. Sachin for example says that there was a stall issue with memoryless nodes that could be triggered without SLQB. Sachin, is that still accurate? If so, it's possible that SLQB somehow exasperates the problem in some unknown fashion. > There does not seem to be an easy way to deal with this. Some > thought needs to go into how memoryless node handling relates to per cpu > lists and locking. List handling issues need to be addressed before SLQB. > can work reliably. The same issues can surface on x86 platforms with weird > NUMA memory setups. > Can you spot if there is something fundamentally wrong with patch 2? I.e. what is wrong with treating the closest node as local instead of only the closest node? > Or just allow SLQB for !NUMA configurations and merge it now. > Forcing SLQB !NUMA will not rattle out any existing list issues unfortunately :(. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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/