From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756502AbaJHN3a (ORCPT ); Wed, 8 Oct 2014 09:29:30 -0400 Received: from cantor2.suse.de ([195.135.220.15]:48108 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753159AbaJHN33 (ORCPT ); Wed, 8 Oct 2014 09:29:29 -0400 Date: Wed, 8 Oct 2014 15:29:27 +0200 From: Michal Hocko To: Johannes Weiner Cc: linux-mm@kvack.org, Vladimir Davydov , Greg Thelen , Tejun Heo , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/3] mm: memcontrol: take a css reference for each charged page Message-ID: <20141008132927.GC4592@dhcp22.suse.cz> References: <1411243235-24680-1-git-send-email-hannes@cmpxchg.org> <1411243235-24680-2-git-send-email-hannes@cmpxchg.org> <20141008132754.GB4592@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141008132754.GB4592@dhcp22.suse.cz> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 08-10-14 15:27:54, Michal Hocko wrote: > On Sat 20-09-14 16:00:33, Johannes Weiner wrote: [...] > > @@ -2803,8 +2808,10 @@ static void memcg_uncharge_kmem(struct mem_cgroup *memcg, > > page_counter_uncharge(&memcg->memsw, nr_pages); > > > > Wouldn't a single out_css_put be more readable? I was quite confused > when I start reading the patch before I saw the next hunk. Ohh, this will go away in the next patch. Ignore this. > > > /* Not down to 0 */ > > - if (page_counter_uncharge(&memcg->kmem, nr_pages)) > goto out_css_put; > > > + if (page_counter_uncharge(&memcg->kmem, nr_pages)) { > > + css_put_many(&memcg->css, nr_pages); > > return; > > + } > > > > /* > > * Releases a reference taken in kmem_cgroup_css_offline in case > > @@ -2816,6 +2823,8 @@ static void memcg_uncharge_kmem(struct mem_cgroup *memcg, > > */ > > if (memcg_kmem_test_and_clear_dead(memcg)) > > css_put(&memcg->css); > > + > > out_css_put: > > + css_put_many(&memcg->css, nr_pages); > > } > > > > /* > -- > Michal Hocko > SUSE Labs -- Michal Hocko SUSE Labs