From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 6A2B26B0022 for ; Fri, 20 May 2011 03:50:50 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 2C8843EE0C0 for ; Fri, 20 May 2011 16:50:45 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 1413A45DE95 for ; Fri, 20 May 2011 16:50:45 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id E48B145DE91 for ; Fri, 20 May 2011 16:50:44 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id D5AD8E18003 for ; Fri, 20 May 2011 16:50:44 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 94B9EE08001 for ; Fri, 20 May 2011 16:50:44 +0900 (JST) Date: Fri, 20 May 2011 16:43:54 +0900 From: KAMEZAWA Hiroyuki Subject: Re: Kernel falls apart under light memory pressure (i.e. linking vmlinux) Message-Id: <20110520164354.d43be406.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20110514165346.GV6008@one.firstfloor.org> <20110514174333.GW6008@one.firstfloor.org> <20110515152747.GA25905@localhost> <20110517060001.GC24069@localhost> <4DD5DC06.6010204@jp.fujitsu.com> <20110520140856.fdf4d1c8.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrea Arcangeli , Andrew Lutomirski , KOSAKI Motohiro , fengguang.wu@intel.com, andi@firstfloor.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mgorman@suse.de, hannes@cmpxchg.org, riel@redhat.com On Fri, 20 May 2011 14:36:13 +0900 Minchan Kim wrote: > On Fri, May 20, 2011 at 2:08 PM, KAMEZAWA Hiroyuki > wrote: > > On Fri, 20 May 2011 13:20:15 +0900 > > Minchan Kim wrote: > > > >> So I want to resolve your problem asap. > >> We don't have see report about that. Could you do git-bisect? > >> FYI, Recently, big change of mm is compaction,transparent huge pages. > >> Kame, could you point out thing related to memcg if you have a mind? > >> > > > > I don't doubt memcg at this stage because it never modify page->flags. > > Consdering the case, PageActive() is set against off-LRU pages after > > clear_active_flags() clears it. > > > > Hmm, I think I don't understand the lock system fully but...how do you > > think this ? > > > > == > > > > At splitting a hugepage, the routine marks all pmd as "splitting". > > > > But assume a racy case where 2 threads run into spit at the > > same time, one thread wins compound_lock() and do split, another > > thread should not touch splitted pages. > > Sorry. Now I don't have a time to review in detail. > When I look it roughly, page_lock_anon_vma have to prevent it. > But Andrea needs current this problem and he will catch something we lost. :) > Hmm, maybe I miss something...need to build a test environ on my side. But I'm not sure I can reproduce it.. Thanks, -Kame -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org