From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id DB43F8D0039 for ; Mon, 21 Feb 2011 08:04:38 -0500 (EST) Date: Mon, 21 Feb 2011 14:04:31 +0100 From: Johannes Weiner Subject: Re: [PATCH v2 1/2] memcg: remove unnecessary BUG_ON Message-ID: <20110221130431.GF25382@cmpxchg.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , Balbir Singh , KAMEZAWA Hiroyuki , Daisuke Nishimura On Mon, Feb 21, 2011 at 12:17:17AM +0900, Minchan Kim wrote: > Now memcg in unmap_and_move checks BUG_ON of charge. > But mem_cgroup_prepare_migration returns either 0 or -ENOMEM. > If it returns -ENOMEM, it jumps out unlock without the check. > If it returns 0, it can pass BUG_ON. So it's meaningless. > Let's remove it. > > Cc: Johannes Weiner > Cc: Balbir Singh > Acked-by: Daisuke Nishimura > Acked-by: KAMEZAWA Hiroyuki > Signed-off-by: Minchan Kim > --- > mm/migrate.c | 1 - > 1 files changed, 0 insertions(+), 1 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index eb083a6..2abc9c9 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -683,7 +683,6 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, > rc = -ENOMEM; > goto unlock; > } > - BUG_ON(charge); You remove this assertion of the mem_cgroup_prepare_migration() return value but only add a comment about the expectations in the next patch. Could you write a full-blown kerneldoc on mem_cgroup_prepare_migration and remove this BUG_ON() in the same patch? -- 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