Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753085Ab2E3TtE (ORCPT ); Wed, 30 May 2012 15:49:04 -0400 Received: from one.firstfloor.org ([213.235.205.2]:48441 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751305Ab2E3TtD (ORCPT ); Wed, 30 May 2012 15:49:03 -0400 Date: Wed, 30 May 2012 21:48:59 +0200 From: Andi Kleen To: Christoph Lameter Cc: kosaki.motohiro@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Dave Jones , Mel Gorman , Linus Torvalds , stable@vger.kernel.org, hughd@google.com, KOSAKI Motohiro , Andrew Morton , andi@firstfloor.org Subject: Re: [PATCH 2/6] mempolicy: Kill all mempolicy sharing Message-ID: <20120530194858.GW27374@one.firstfloor.org> References: <1338368529-21784-1-git-send-email-kosaki.motohiro@gmail.com> <1338368529-21784-3-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: 1181 Lines: 28 On Wed, May 30, 2012 at 02:41:22PM -0500, Christoph Lameter wrote: > On Wed, 30 May 2012, kosaki.motohiro@gmail.com wrote: > > > refcount will be decreased even though was not increased whenever alloc_page_vma() > > is called. As you know, mere mbind(MPOL_MF_MOVE) calls alloc_page_vma(). > > Most of these issues are about memory migration and shared memory. If we > exempt shared memory from memory migration (after all that shared memory > has its own distinct memory policies already!) then a lot of these issues > wont arise. Soft memory offlining needs migration. It's fairly important that this works: on the database systems most memory is in shared memory and they have a lot of memory, so predictive failure analysis and soft offlining helps a lot. Classic migration is probably not too important here, but they pretty much rely on the same low level mechanism. -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/