From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752395AbaJTSxO (ORCPT ); Mon, 20 Oct 2014 14:53:14 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:59051 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751914AbaJTSxK (ORCPT ); Mon, 20 Oct 2014 14:53:10 -0400 Date: Mon, 20 Oct 2014 20:53:06 +0200 From: Michal Hocko To: Vladimir Davydov Cc: Andrew Morton , Johannes Weiner , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -mm] memcg: remove activate_kmem_mutex Message-ID: <20141020185306.GB505@dhcp22.suse.cz> References: <1413817889-13915-1-git-send-email-vdavydov@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1413817889-13915-1-git-send-email-vdavydov@parallels.com> 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 Mon 20-10-14 19:11:29, Vladimir Davydov wrote: > The activate_kmem_mutex is used to serialize memcg.kmem.limit updates, > but we already serialize them with memcg_limit_mutex so let's remove the > former. > > Signed-off-by: Vladimir Davydov Is this the case since bd67314586a3 (memcg, slab: simplify synchronization scheme)? Anyway Looks good to me. Acked-by: Michal Hocko > --- > mm/memcontrol.c | 24 +++++------------------- > 1 file changed, 5 insertions(+), 19 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 3a203c7ec6c7..e957f0c80c6e 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2618,8 +2618,6 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg, > */ > static DEFINE_MUTEX(memcg_slab_mutex); > > -static DEFINE_MUTEX(activate_kmem_mutex); > - > /* > * This is a bit cumbersome, but it is rarely used and avoids a backpointer > * in the memcg_cache_params struct. > @@ -3756,9 +3754,8 @@ static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css, > } > > #ifdef CONFIG_MEMCG_KMEM > -/* should be called with activate_kmem_mutex held */ > -static int __memcg_activate_kmem(struct mem_cgroup *memcg, > - unsigned long nr_pages) > +static int memcg_activate_kmem(struct mem_cgroup *memcg, > + unsigned long nr_pages) > { > int err = 0; > int memcg_id; > @@ -3820,17 +3817,6 @@ out: > return err; > } > > -static int memcg_activate_kmem(struct mem_cgroup *memcg, > - unsigned long nr_pages) > -{ > - int ret; > - > - mutex_lock(&activate_kmem_mutex); > - ret = __memcg_activate_kmem(memcg, nr_pages); > - mutex_unlock(&activate_kmem_mutex); > - return ret; > -} > - > static int memcg_update_kmem_limit(struct mem_cgroup *memcg, > unsigned long limit) > { > @@ -3853,14 +3839,14 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg) > if (!parent) > return 0; > > - mutex_lock(&activate_kmem_mutex); > + mutex_lock(&memcg_limit_mutex); > /* > * If the parent cgroup is not kmem-active now, it cannot be activated > * after this point, because it has at least one child already. > */ > if (memcg_kmem_is_active(parent)) > - ret = __memcg_activate_kmem(memcg, PAGE_COUNTER_MAX); > - mutex_unlock(&activate_kmem_mutex); > + ret = memcg_activate_kmem(memcg, PAGE_COUNTER_MAX); > + mutex_unlock(&memcg_limit_mutex); > return ret; > } > #else > -- > 1.7.10.4 > -- Michal Hocko SUSE Labs