Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757154Ab2E3Sqq (ORCPT ); Wed, 30 May 2012 14:46:46 -0400 Received: from one.firstfloor.org ([213.235.205.2]:48346 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754147Ab2E3Sqo (ORCPT ); Wed, 30 May 2012 14:46:44 -0400 Date: Wed, 30 May 2012 20:46:38 +0200 From: Andi Kleen To: Christoph Lameter Cc: Linus Torvalds , kosaki.motohiro@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Dave Jones , Mel Gorman , stable@vger.kernel.org, hughd@google.com, sivanich@sgi.com, KOSAKI Motohiro , andi@firstfloor.org Subject: Re: [PATCH 0/6] mempolicy memory corruption fixlet Message-ID: <20120530184638.GU27374@one.firstfloor.org> References: <1338368529-21784-1-git-send-email-kosaki.motohiro@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1767 Lines: 48 On Wed, May 30, 2012 at 01:34:21PM -0500, Christoph Lameter wrote: > On Wed, 30 May 2012, Linus Torvalds wrote: > > > On Wed, May 30, 2012 at 2:02 AM, wrote: > > > > > > So, I think we should reconsider about shared mempolicy completely. > > > > Quite frankly, I'd prefer that approach. The code is subtle and > > horribly bug-fraught, and I absolutely detest the way it looks too. > > Reading your patches was actually somewhat painful. > > It is so bad mostly because the integration of shared memory policies with > cpusets is not really working. Using either in isolation is ok especially > shared mempolicies do not play well with cpusets. Yes the cpusets did some horrible things. I always regretted that cpusets were no done with custom node lists. That would have been much cleaner and also likely faster than what we have. > > If we could just remove the support for it entirely, that would be > > *much* preferable to continue working with this code. > > Well shm support needs memory policies to spread data across nodes etc. > AFAICT support was put in due to requirements to support large database > vendors (oracle). Andi? Yes we need shared policy for the big databases. Maybe we could stop supporting cpusets with that though. Not sure they really use that. > Its not going to be easy to remove. Shared policies? I don't think you can remove them. cpusets+shared policy? maybe, but still will be hard. -Andi > -- ak@linux.intel.com -- Speaking for myself only. -- 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/