From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with SMTP id F31526B01E3 for ; Mon, 26 Apr 2010 00:31:59 -0400 (EDT) Received: by iwn40 with SMTP id 40so2897372iwn.1 for ; Sun, 25 Apr 2010 21:31:59 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20100426115347.2ee2a917.kamezawa.hiroyu@jp.fujitsu.com> References: <20100423120148.9ffa5881.kamezawa.hiroyu@jp.fujitsu.com> <20100423095922.GJ30306@csn.ul.ie> <20100423155801.GA14351@csn.ul.ie> <20100424110200.b491ec5f.kamezawa.hiroyu@jp.fujitsu.com> <20100424104324.GD14351@csn.ul.ie> <20100426084901.15c09a29.kamezawa.hiroyu@jp.fujitsu.com> <20100426115347.2ee2a917.kamezawa.hiroyu@jp.fujitsu.com> Date: Mon, 26 Apr 2010 13:31:59 +0900 Message-ID: Subject: Re: [BUGFIX][mm][PATCH] fix migration race in rmap_walk From: Minchan Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Mel Gorman , "linux-mm@kvack.org" , Christoph Lameter , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" List-ID: On Mon, Apr 26, 2010 at 11:53 AM, KAMEZAWA Hiroyuki wrote: > On Mon, 26 Apr 2010 08:49:01 +0900 > KAMEZAWA Hiroyuki wrote: > >> On Sat, 24 Apr 2010 11:43:24 +0100 >> Mel Gorman wrote: > >> > It looks nice but it still broke after 28 hours of running. The >> > seq-counter is still insufficient to catch all changes that are made to >> > the list. I'm beginning to wonder if a) this really can be fully safely >> > locked with the anon_vma changes and b) if it has to be a spinlock to >> > catch the majority of cases but still a lazy cleanup if there happens to >> > be a race. It's unsatisfactory and I'm expecting I'll either have some >> > insight to the new anon_vma changes that allow it to be locked or Rik >> > knows how to restore the original behaviour which as Andrea pointed out >> > was safe. >> > >> Ouch. Hmm, how about the race in fork() I pointed out ? >> > Forget this. Sorry for noise. Yes. It was due to my wrong explanation. Sorry for that, Kame. -- Kind regards, Minchan Kim -- 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