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 7140B6004C0 for ; Sat, 1 May 2010 21:56:52 -0400 (EDT) Date: Sat, 1 May 2010 20:56:18 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH 2/2] mm,migration: Avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks In-Reply-To: <1272529930-29505-3-git-send-email-mel@csn.ul.ie> Message-ID: References: <1272529930-29505-1-git-send-email-mel@csn.ul.ie> <1272529930-29505-3-git-send-email-mel@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Andrew Morton , Linux-MM , LKML , Minchan Kim , KAMEZAWA Hiroyuki , Andrea Arcangeli , Rik van Riel List-ID: On Thu, 29 Apr 2010, Mel Gorman wrote: > There is a race between shift_arg_pages and migration that triggers this bug. > A temporary stack is setup during exec and later moved. If migration moves > a page in the temporary stack and the VMA is then removed before migration > completes, the migration PTE may not be found leading to a BUG when the > stack is faulted. A simpler solution would be to not allow migration of the temporary stack? -- 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