From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx169.postini.com [74.125.245.169]) by kanga.kvack.org (Postfix) with SMTP id 14D1A6B0028 for ; Mon, 28 Jan 2013 19:12:51 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 2DAAD3EE0AE for ; Tue, 29 Jan 2013 09:12:49 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 117C445DE59 for ; Tue, 29 Jan 2013 09:12:49 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id EBBB645DE54 for ; Tue, 29 Jan 2013 09:12:48 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id C5D5FE08002 for ; Tue, 29 Jan 2013 09:12:48 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 7CF1B1DB802F for ; Tue, 29 Jan 2013 09:12:48 +0900 (JST) Message-ID: <510713F3.9040207@jp.fujitsu.com> Date: Tue, 29 Jan 2013 09:12:35 +0900 From: Kamezawa Hiroyuki MIME-Version: 1.0 Subject: Re: [PATCH v4 2/6] memcg: split part of memcg creation to css_online References: <1358862461-18046-1-git-send-email-glommer@parallels.com> <1358862461-18046-3-git-send-email-glommer@parallels.com> In-Reply-To: <1358862461-18046-3-git-send-email-glommer@parallels.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Tejun Heo , Michal Hocko , Johannes Weiner (2013/01/22 22:47), Glauber Costa wrote: > This patch is a preparatory work for later locking rework to get rid of > big cgroup lock from memory controller code. > > The memory controller uses some tunables to adjust its operation. Those > tunables are inherited from parent to children upon children > intialization. For most of them, the value cannot be changed after the > parent has a new children. > > cgroup core splits initialization in two phases: css_alloc and css_online. > After css_alloc, the memory allocation and basic initialization are > done. But the new group is not yet visible anywhere, not even for cgroup > core code. It is only somewhere between css_alloc and css_online that it > is inserted into the internal children lists. Copying tunable values in > css_alloc will lead to inconsistent values: the children will copy the > old parent values, that can change between the copy and the moment in > which the groups is linked to any data structure that can indicate the > presence of children. > > Signed-off-by: Glauber Costa > Acked-by: Michal Hocko 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/ . Don't email: email@kvack.org