From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx201.postini.com [74.125.245.201]) by kanga.kvack.org (Postfix) with SMTP id 228826B004F for ; Mon, 23 Jan 2012 23:49:16 -0500 (EST) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 437A43EE081 for ; Tue, 24 Jan 2012 13:49:14 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 2822845DEAD for ; Tue, 24 Jan 2012 13:49:14 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 0FCC645DEA6 for ; Tue, 24 Jan 2012 13:49:14 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 039371DB803B for ; Tue, 24 Jan 2012 13:49:14 +0900 (JST) Received: from m106.s.css.fujitsu.com (m106.s.css.fujitsu.com [10.240.81.146]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id B1DA61DB803E for ; Tue, 24 Jan 2012 13:49:13 +0900 (JST) Date: Tue, 24 Jan 2012 13:47:50 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC] [PATCH 3/7 v2] memcg: remove PCG_MOVE_LOCK flag from pc->flags Message-Id: <20120124134750.de5f31ee.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20120113173001.ee5260ca.kamezawa.hiroyu@jp.fujitsu.com> <20120113174019.8dff3fc1.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Ying Han Cc: "linux-mm@kvack.org" , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , Michal Hocko , cgroups@vger.kernel.org, "bsingharora@gmail.com" On Mon, 23 Jan 2012 14:02:48 -0800 Ying Han wrote: > On Fri, Jan 13, 2012 at 12:40 AM, KAMEZAWA Hiroyuki > wrote: > > > > From 1008e84d94245b1e7c4d237802ff68ff00757736 Mon Sep 17 00:00:00 2001 > > From: KAMEZAWA Hiroyuki > > Date: Thu, 12 Jan 2012 15:53:24 +0900 > > Subject: [PATCH 3/7] memcg: remove PCG_MOVE_LOCK flag from pc->flags. > > > > PCG_MOVE_LOCK bit is used for bit spinlock for avoiding race between > > memcg's account moving and page state statistics updates. > > > > Considering page-statistics update, very hot path, this lock is > > taken only when someone is moving account (or PageTransHuge()) > > And, now, all moving-account between memcgroups (by task-move) > > are serialized. > > This might be a side question, can you clarify the serialization here? > Does it mean that we only allow one task-move at a time system-wide? > current implementation has that limit by mutex. Thanks, -Kame -- 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