From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by e28esmtp05.in.ibm.com (8.13.1/8.13.1) with ESMTP id m87FXXXT028309 for ; Sun, 7 Sep 2008 21:03:33 +0530 Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m87FXU2C1769558 for ; Sun, 7 Sep 2008 21:03:33 +0530 Received: from d28av01.in.ibm.com (loopback [127.0.0.1]) by d28av01.in.ibm.com (8.13.1/8.13.3) with ESMTP id m87FXTkX008806 for ; Sun, 7 Sep 2008 21:03:30 +0530 Message-ID: <48C3F444.4060908@linux.vnet.ibm.com> Date: Sun, 07 Sep 2008 21:03:24 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [PATCH][mmotm]memcg: handle null dereference of mm->owner References: <20080905165017.b2715fe4.nishimura@mxp.nes.nec.co.jp> <20080905174021.9fa29b01.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830809050903s7e1a1004i6b31660502c0dcf2@mail.gmail.com> In-Reply-To: <6599ad830809050903s7e1a1004i6b31660502c0dcf2@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Menage Cc: KAMEZAWA Hiroyuki , Daisuke Nishimura , Andrew Morton , Hugh Dickins , Li Zefan , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Paul Menage wrote: > On Fri, Sep 5, 2008 at 1:40 AM, KAMEZAWA Hiroyuki > wrote: >> BTW, I have a question to Balbir and Paul. (I'm sorry I missed the discussion.) >> Recently I wonder why we need MM_OWNER. >> >> - What's bad with thread's cgroup ? > > Because lots of mm operations take place in a context where we don't > have a thread pointer, and hence no cgroup. > Right, Thanks! Allocating memory is not that big a problem (we usually know the context), while freeing memory, we can't assume that current is freeing it -- Balbir -- 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