From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx102.postini.com [74.125.245.102]) by kanga.kvack.org (Postfix) with SMTP id CD7CB6B005C for ; Thu, 5 Jan 2012 01:03:08 -0500 (EST) Received: from m1.gw.fujitsu.co.jp (unknown [10.0.50.71]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 670A53EE081 for ; Thu, 5 Jan 2012 15:03:07 +0900 (JST) Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 4384645DE54 for ; Thu, 5 Jan 2012 15:03:07 +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 1F84B45DE5A for ; Thu, 5 Jan 2012 15:03:07 +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 0AFDE1DB8054 for ; Thu, 5 Jan 2012 15:03:07 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id B4A481DB804C for ; Thu, 5 Jan 2012 15:03:06 +0900 (JST) Date: Thu, 5 Jan 2012 15:01:50 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 4/4] memcg: fix mem_cgroup_print_bad_page Message-Id: <20120105150150.436dfce8.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Andrew Morton , Daisuke Nishimura , Johannes Weiner , Michal Hocko , linux-mm@kvack.org On Wed, 28 Dec 2011 16:26:02 -0800 (PST) Hugh Dickins wrote: > If DEBUG_VM, mem_cgroup_print_bad_page() is called whenever bad_page() > shows a "Bad page state" message, removes page from circulation, adds a > taint and continues. This is at a very low level, often when a spinlock > is held (sometimes when page table lock is held, for example). > > We want to recover from this badness, not make it worse: we must not > kmalloc memory here, we must not do a cgroup path lookup via dubious > pointers. No doubt that code was useful to debug a particular case > at one time, and may be again, but take it out of the mainline kernel. > > Signed-off-by: Hugh Dickins Acked-by: KAMEZAWA Hiroyuki -- 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