Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757385Ab0DVTmb (ORCPT ); Thu, 22 Apr 2010 15:42:31 -0400 Received: from nlpi129.sbcis.sbc.com ([207.115.36.143]:40569 "EHLO nlpi129.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756775Ab0DVTm2 (ORCPT ); Thu, 22 Apr 2010 15:42:28 -0400 Date: Thu, 22 Apr 2010 14:40:46 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@router.home To: Mel Gorman cc: Minchan Kim , KAMEZAWA Hiroyuki , Andrew Morton , Andrea Arcangeli , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 04/14] mm,migration: Allow the migration of PageSwapCache pages In-Reply-To: <20100422192923.GH30306@csn.ul.ie> Message-ID: References: <20100421153421.GM30306@csn.ul.ie> <20100422092819.GR30306@csn.ul.ie> <20100422184621.0aaaeb5f.kamezawa.hiroyu@jp.fujitsu.com> <20100422193106.9ffad4ec.kamezawa.hiroyu@jp.fujitsu.com> <20100422195153.d91c1c9e.kamezawa.hiroyu@jp.fujitsu.com> <20100422141404.GA30306@csn.ul.ie> <20100422154003.GC30306@csn.ul.ie> <20100422192923.GH30306@csn.ul.ie> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 739 Lines: 15 On Thu, 22 Apr 2010, Mel Gorman wrote: > vma_adjust() is updating anon VMA information without any locks taken. > In constract, file-backed mappings use the i_mmap_lock. This lack of > locking can result in races with page migration. During rmap_walk(), > vma_address() can return -EFAULT for an address that will soon be valid. > This leaves a dangling migration PTE behind which can later cause a > BUG_ON to trigger when the page is faulted in. Isnt this also a race with reclaim / swap? -- 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/