From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id C64D46B0096 for ; Thu, 24 Nov 2011 04:06:50 -0500 (EST) Date: Thu, 24 Nov 2011 10:06:39 +0100 From: Johannes Weiner Subject: Re: [patch 6/8] mm: memcg: remove unneeded checks from uncharge_page() Message-ID: <20111124090639.GD6843@cmpxchg.org> References: <1322062951-1756-1-git-send-email-hannes@cmpxchg.org> <1322062951-1756-7-git-send-email-hannes@cmpxchg.org> <20111124090619.895988e7.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111124090619.895988e7.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Michal Hocko , Balbir Singh , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, Nov 24, 2011 at 09:06:19AM +0900, KAMEZAWA Hiroyuki wrote: > On Wed, 23 Nov 2011 16:42:29 +0100 > Johannes Weiner wrote: > > > From: Johannes Weiner > > > > mem_cgroup_uncharge_page() is only called on either freshly allocated > > pages without page->mapping or on rmapped PageAnon() pages. There is > > no need to check for a page->mapping that is not an anon_vma. > > > > Signed-off-by: Johannes Weiner > > For making our assumption clearer to readers of codes, > VM_BUG_ON(page->mapping && !PageAnon(page)) please. Yep, delta patch below. > Anyway, > Acked-by: KAMEZAWA Hiroyuki Thanks! --- From: Johannes Weiner Subject: mm: memcg: remove unneeded checks from uncharge_page() fix Document page state assumptions and catch if they are violated in uncharge_page(). Signed-off-by: Johannes Weiner --- mm/memcontrol.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2f1fdc4..872dae1 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2992,6 +2992,7 @@ void mem_cgroup_uncharge_page(struct page *page) /* early check. */ if (page_mapped(page)) return; + VM_BUG_ON(page->mapping && !PageAnon(page)); __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED); } -- 1.7.6.4 -- 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