From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 08FC76B01EE for ; Tue, 27 Apr 2010 21:09:53 -0400 (EDT) Date: Wed, 28 Apr 2010 03:09:20 +0200 From: Andrea Arcangeli Subject: Re: [PATCH 3/3] mm,migration: Remove straggling migration PTEs when page tables are being moved after the VMA has already moved Message-ID: <20100428010920.GK510@random.random> References: <1272403852-10479-1-git-send-email-mel@csn.ul.ie> <1272403852-10479-4-git-send-email-mel@csn.ul.ie> <20100427223004.GF8860@random.random> <20100427225852.GH8860@random.random> <20100428093948.c4e6faa1.kamezawa.hiroyu@jp.fujitsu.com> <20100428010543.GJ510@random.random> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100428010543.GJ510@random.random> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Mel Gorman , Linux-MM , LKML , Minchan Kim , Christoph Lameter , Rik van Riel , Andrew Morton List-ID: On Wed, Apr 28, 2010 at 03:05:43AM +0200, Andrea Arcangeli wrote: > 1) adjusting page->index atomically with the pte updates inside pt > lock (while it moves from one pte to another) actually no need of this at all! of course the dst vma will have vma->vm_pgoff adjusted instead... never mind. So I don't see a problem there. I think this is very special of how exec.c abuses move_page_tables by passing vma as src and dst, when it obviously cannot be indexed in two anon-vmas because there's a single vma and a single vma->anon_vma, and src and dst obviously cannot have two different vm_pgoff again because there's a single vma and there can't be two different vma->vm_pgoff. So I'm very hopeful do_mremap is already fully safe... -- 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