From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx206.postini.com [74.125.245.206]) by kanga.kvack.org (Postfix) with SMTP id 691086B004A for ; Tue, 28 Feb 2012 19:01:35 -0500 (EST) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 894BE3EE0BC for ; Wed, 29 Feb 2012 09:01:33 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 6D96645DE4E for ; Wed, 29 Feb 2012 09:01:33 +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 3FF9445DE50 for ; Wed, 29 Feb 2012 09:01:33 +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 2FDEB1DB8042 for ; Wed, 29 Feb 2012 09:01:33 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.240.81.147]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id DC5371DB803E for ; Wed, 29 Feb 2012 09:01:32 +0900 (JST) Date: Wed, 29 Feb 2012 09:00:05 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [patch 1/2] kernel: cgroup: push rcu read locking from css_is_ancestor() to callsite Message-Id: <20120229090005.1ef4cdb2.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1330438489-21909-1-git-send-email-hannes@cmpxchg.org> References: <1330438489-21909-1-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Konstantin Khlebnikov , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 28 Feb 2012 15:14:48 +0100 Johannes Weiner wrote: > Library functions should not grab locks when the callsites can do it, > even if the lock nests like the rcu read-side lock does. > > Push the rcu_read_lock() from css_is_ancestor() to its single user, > mem_cgroup_same_or_subtree() in preparation for another user that may > already hold the rcu read-side lock. > > Signed-off-by: Johannes Weiner 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