From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id B31556B00E9 for ; Mon, 24 Jan 2011 05:14:09 -0500 (EST) Date: Mon, 24 Jan 2011 11:14:02 +0100 From: Johannes Weiner Subject: Re: [PATCH 1/7] memcg : comment, style fixes for recent patch of move_parent Message-ID: <20110124101402.GT2232@cmpxchg.org> References: <20110121153431.191134dd.kamezawa.hiroyu@jp.fujitsu.com> <20110121153726.54f4a159.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110121153726.54f4a159.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "nishimura@mxp.nes.nec.co.jp" , "balbir@linux.vnet.ibm.com" , "akpm@linux-foundation.org" List-ID: On Fri, Jan 21, 2011 at 03:37:26PM +0900, KAMEZAWA Hiroyuki wrote: > From: KAMEZAWA Hiroyuki > > A fix for 987eba66e0e6aa654d60881a14731a353ee0acb4 > > A clean up for mem_cgroup_move_parent(). > - remove unnecessary initialization of local variable. > - rename charge_size -> page_size > - remove unnecessary (wrong) comment. > > Signed-off-by: KAMEZAWA Hiroyuki > --- > mm/memcontrol.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > Index: mmotm-0107/mm/memcontrol.c > =================================================================== > --- mmotm-0107.orig/mm/memcontrol.c > +++ mmotm-0107/mm/memcontrol.c > @@ -2265,7 +2265,7 @@ static int mem_cgroup_move_parent(struct > struct cgroup *cg = child->css.cgroup; > struct cgroup *pcg = cg->parent; > struct mem_cgroup *parent; > - int charge = PAGE_SIZE; > + int page_size; > unsigned long flags; > int ret; > > @@ -2278,22 +2278,23 @@ static int mem_cgroup_move_parent(struct > goto out; > if (isolate_lru_page(page)) > goto put; > - /* The page is isolated from LRU and we have no race with splitting */ > - charge = PAGE_SIZE << compound_order(page); > + > + page_size = PAGE_SIZE << compound_order(page); Okay, so you remove the wrong comment, but that does not make the code right. What protects compound_order from reading garbage because the page is currently splitting? -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org