From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 45C3D6B0096 for ; Mon, 21 Sep 2009 14:07:37 -0400 (EDT) Date: Mon, 21 Sep 2009 19:07:39 +0100 From: Mel Gorman 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: Sender: owner-linux-mm@kvack.org 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 List-ID: 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, 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/ . Don't email: email@kvack.org