From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id B22636B01EF for ; Wed, 12 May 2010 19:06:56 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o4CN6rsq018361 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 13 May 2010 08:06:53 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 70AAF45DE50 for ; Thu, 13 May 2010 08:06:53 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 459F145DE51 for ; Thu, 13 May 2010 08:06:53 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 18CB71DB8054 for ; Thu, 13 May 2010 08:06:53 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id AE7A01DB8051 for ; Thu, 13 May 2010 08:06:52 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] mm,migration: Avoid race between shift_arg_pages() and rmap_walk() during migration by not migrating temporary stacks In-Reply-To: <20100512205150.GL24989@csn.ul.ie> References: <20100512125427.d1b170ba.akpm@linux-foundation.org> <20100512205150.GL24989@csn.ul.ie> Message-Id: <20100513080600.2139.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 13 May 2010 08:06:51 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , Linus Torvalds , KAMEZAWA Hiroyuki , Linux-MM , LKML , Minchan Kim , Christoph Lameter , Andrea Arcangeli , Rik van Riel , Peter Zijlstra List-ID: > On Wed, May 12, 2010 at 12:54:27PM -0700, Andrew Morton wrote: > > On Wed, 12 May 2010 09:23:44 +0900 (JST) > > KOSAKI Motohiro wrote: > > > > > > diff --git a/fs/exec.c b/fs/exec.c > > > > index 725d7ef..13f8e7f 100644 > > > > --- a/fs/exec.c > > > > +++ b/fs/exec.c > > > > @@ -242,9 +242,10 @@ static int __bprm_mm_init(struct linux_binprm *bprm) > > > > * use STACK_TOP because that can depend on attributes which aren't > > > > * configured yet. > > > > */ > > > > + BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); > > > > > > Can we use BUILD_BUG_ON()? > > > > That's vastly preferable - I made that change. > > I will be surprised if it works. On x86, that is > > #define VM_STACK_FLAGS (VM_GROWSDOWN | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) > #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS > #define VM_DATA_DEFAULT_FLAGS \ > (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \ > VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) > > so VM_STACK_FLAGS is depending on the value of current->personality > which we don't know at build time. Argh, yes right you are. sorry for the noise. -- 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