From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx200.postini.com [74.125.245.200]) by kanga.kvack.org (Postfix) with SMTP id 7DC696B005D for ; Wed, 30 May 2012 16:01:17 -0400 (EDT) Received: by ggm4 with SMTP id 4so243264ggm.14 for ; Wed, 30 May 2012 13:01:16 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20120530195244.GX27374@one.firstfloor.org> 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> From: KOSAKI Motohiro Date: Wed, 30 May 2012 16:00:55 -0400 Message-ID: Subject: Re: [PATCH 0/6] mempolicy memory corruption fixlet Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: 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 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. page migration for hwpoison is harmless. Because of, an attacker can't inject hwpoison intentntionally on production environment (HWPOISON_INJECTION=N). -- 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