Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754218Ab0KIUBZ (ORCPT ); Tue, 9 Nov 2010 15:01:25 -0500 Received: from smtp-out.google.com ([74.125.121.35]:13508 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752513Ab0KIUBW (ORCPT ); Tue, 9 Nov 2010 15:01:22 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=from:to:cc:subject:references:date:message-id:user-agent: mime-version:content-type; b=mN/KgKhfFoSXVuoagh9h4ytRSeOKiB+qZmnb/V7n/BzOaC6JRcoQ8EPh7GA21HwOK Db9nmhb6XVm28nty2xcRA== From: Greg Thelen To: Johannes Weiner Cc: Andrew Morton , David Rientjes , KAMEZAWA Hiroyuki , Balbir Singh , Daisuke Nishimura , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch] memcg: fix unit mismatch in memcg oom limit calculation References: <20101109110521.GS23393@cmpxchg.org> Date: Tue, 09 Nov 2010 12:00:26 -0800 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1455 Lines: 40 Johannes Weiner writes: > Adding the number of swap pages to the byte limit of a memory control > group makes no sense. Convert the pages to bytes before adding them. > > The only user of this code is the OOM killer, and the way it is used > means that the error results in a higher OOM badness value. Since the > cgroup limit is the same for all tasks in the cgroup, the error should > have no practical impact at the moment. > > But let's not wait for future or changing users to trip over it. Thanks for the fix. > Signed-off-by: Johannes Weiner Reviewed-by: Greg Thelen > --- > mm/memcontrol.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1552,8 +1552,9 @@ u64 mem_cgroup_get_limit(struct mem_cgro > u64 limit; > u64 memsw; > > - limit = res_counter_read_u64(&memcg->res, RES_LIMIT) + > - total_swap_pages; > + limit = res_counter_read_u64(&memcg->res, RES_LIMIT); > + limit += total_swap_pages << PAGE_SHIFT; > + > memsw = res_counter_read_u64(&memcg->memsw, RES_LIMIT); > /* > * If memsw is finite and limits the amount of swap space available -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/