From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 33D396B01EF for ; Mon, 26 Apr 2010 17:55:04 -0400 (EDT) Message-ID: <4BD60B80.8050605@redhat.com> Date: Mon, 26 Apr 2010 17:54:08 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH 04/14] mm,migration: Allow the migration of PageSwapCache pages References: <20100422195153.d91c1c9e.kamezawa.hiroyu@jp.fujitsu.com> <1271946226.2100.211.camel@barrios-desktop> <1271947206.2100.216.camel@barrios-desktop> <20100422154443.GD30306@csn.ul.ie> <20100423183135.GT32034@random.random> <20100423192311.GC14351@csn.ul.ie> <20100423193948.GU32034@random.random> <20100423213549.GV32034@random.random> <20100424105226.GF14351@csn.ul.ie> <20100424111340.GB32034@random.random> <20100424115936.GG14351@csn.ul.ie> In-Reply-To: <20100424115936.GG14351@csn.ul.ie> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Andrea Arcangeli , Minchan Kim , KAMEZAWA Hiroyuki , Christoph Lameter , Andrew Morton , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On 04/24/2010 07:59 AM, Mel Gorman wrote: > On Sat, Apr 24, 2010 at 01:13:40PM +0200, Andrea Arcangeli wrote: >> Also keep in mind expand_downwards which also adjusts >> vm_start/vm_pgoff the same way (and without mmap_sem write mode). > > Will keep it in mind. It's taking the anon_vma lock but once again, > there might be more than one anon_vma to worry about and the proper > locking still isn't massively clear to me. The locking for the anon_vma_chain->same_vma list is essentially the same as what was used before in mmap and anon_vma_prepare. Either the mmap_sem is held for write, or the mmap_sem is held for reading and the page_table_lock is held. What exactly is the problem that migration is seeing? -- All rights reversed -- 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