From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 10B4A6B005C for ; Wed, 30 May 2012 17:22:49 -0400 (EDT) Date: Wed, 30 May 2012 22:22:36 +0100 From: Ben Hutchings Message-ID: <20120530212235.GB20051@decadent.org.uk> References: <1338368529-21784-1-git-send-email-kosaki.motohiro@gmail.com> <20120530184638.GU27374@one.firstfloor.org> <20120530193234.GV27374@one.firstfloor.org> <20120530195244.GX27374@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [PATCH 0/6] mempolicy memory corruption fixlet Sender: owner-linux-mm@kvack.org List-ID: To: KOSAKI Motohiro Cc: Andi Kleen , Christoph Lameter , Linus Torvalds , 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 On Wed, May 30, 2012 at 04:00:55PM -0400, KOSAKI Motohiro wrote: > On Wed, May 30, 2012 at 3:52 PM, Andi Kleen wrote: > > On Wed, May 30, 2012 at 02:42:42PM -0500, Christoph Lameter wrote: > >> On Wed, 30 May 2012, Andi Kleen wrote: > >> > >> > On Wed, May 30, 2012 at 01:50:02PM -0500, Christoph Lameter wrote: > >> > > On Wed, 30 May 2012, Andi Kleen wrote: > >> > > > >> > > > 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. > >> > > > >> > > Could shared memory policies ignore cpuset constraints? > >> > > >> > Only if noone uses cpusets as a "security" mechanism, just for a "soft policy" > >> > Even with soft policy you could well break someone's setup. > >> > >> Well at least lets exempt shared memory from memory migration and memory > >> policy updates. That seems to be causing many of these issues. > > > > Migration on the page level is needed for the memory error handling. > > > > Updates: you mean not allowing to set the policy when there are already > > multiple mappers? I could see that causing some unexpected behaviour. Presumably > > a standard database will only set it at the beginning, but I don't know > > if that would work for all users. > > We don't need to kill migration core. We only need to kill that mbind(2) updates > vma->policy of shmem. [...] So should I (and Greg) drop 'mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages' from the pending stable releases? Or is that OK as an interim fix until these changes go into mainline? Ben. -- Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camus -- 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