From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from wpaz5.hot.corp.google.com (wpaz5.hot.corp.google.com [172.24.198.69]) by smtp-out.google.com with ESMTP id mBA90i3K022883 for ; Wed, 10 Dec 2008 01:00:44 -0800 Received: from rv-out-0506.google.com (rvfb25.prod.google.com [10.140.179.25]) by wpaz5.hot.corp.google.com with ESMTP id mBA90gcb009402 for ; Wed, 10 Dec 2008 01:00:43 -0800 Received: by rv-out-0506.google.com with SMTP id b25so348245rvf.39 for ; Wed, 10 Dec 2008 01:00:42 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <62469.10.75.179.62.1228476245.squirrel@webmail-b.css.fujitsu.com> References: <20081205172642.565661b1.kamezawa.hiroyu@jp.fujitsu.com> <20081205172845.2b9d89a5.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830812050139l5797f16kaf511f831b09e8f4@mail.gmail.com> <62469.10.75.179.62.1228476245.squirrel@webmail-b.css.fujitsu.com> Date: Wed, 10 Dec 2008 01:00:42 -0800 Message-ID: <6599ad830812100100i54132600he52504b4785542ec@mail.gmail.com> Subject: Re: [RFC][PATCH 1/4] New css->refcnt implementation. From: Paul Menage Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , "lizf@cn.fujitsu.com" , "linux-kernel@vger.kernel.org" List-ID: On Fri, Dec 5, 2008 at 3:24 AM, KAMEZAWA Hiroyuki wrote: >> The basic rule is that you're only supposed to increment the css >> refcount if you have: >> >> - a reference to a task in the cgroup (that is pinned via task_lock() >> so it can't be moved away) >> or >> - an existing reference to the css >> > My problem is that we can do css_get() after pre_destroy() and > css's refcnt goes down to 0. But where are you getting the reference from in order to do css_get()? Which call in mem cgroup are you concerned about? Paul -- 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