From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752233AbaBJORT (ORCPT ); Mon, 10 Feb 2014 09:17:19 -0500 Received: from mail-wi0-f177.google.com ([209.85.212.177]:45356 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751449AbaBJORR (ORCPT ); Mon, 10 Feb 2014 09:17:17 -0500 Date: Mon, 10 Feb 2014 15:17:13 +0100 From: Michal Hocko To: Johannes Weiner Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 1/8] mm: memcg: remove unnecessary preemption disabling Message-ID: <20140210141713.GG7117@dhcp22.suse.cz> References: <1391792665-21678-1-git-send-email-hannes@cmpxchg.org> <1391792665-21678-2-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1391792665-21678-2-git-send-email-hannes@cmpxchg.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 07-02-14 12:04:18, Johannes Weiner wrote: > lock_page_cgroup() disables preemption, remove explicit preemption > disabling for code paths holding this lock. > > Signed-off-by: Johannes Weiner It would be better to document the dependency on lock_page_cgroup. But the patch looks correct. Acked-by: Michal Hocko > --- > mm/memcontrol.c | 15 ++++----------- > 1 file changed, 4 insertions(+), 11 deletions(-) > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 53385cd4e6f0..befb3dd9d46c 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -921,8 +921,6 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, > struct page *page, > bool anon, int nr_pages) > { > - preempt_disable(); > - > /* > * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is > * counted as CACHE even if it's on ANON LRU. > @@ -947,8 +945,6 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, > } > > __this_cpu_add(memcg->stat->nr_page_events, nr_pages); > - > - preempt_enable(); > } > > unsigned long > @@ -3780,17 +3776,14 @@ void mem_cgroup_split_huge_fixup(struct page *head) > } > #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ > > -static inline > -void mem_cgroup_move_account_page_stat(struct mem_cgroup *from, > - struct mem_cgroup *to, > - unsigned int nr_pages, > - enum mem_cgroup_stat_index idx) > +static void mem_cgroup_move_account_page_stat(struct mem_cgroup *from, > + struct mem_cgroup *to, > + unsigned int nr_pages, > + enum mem_cgroup_stat_index idx) > { > /* Update stat data for mem_cgroup */ > - preempt_disable(); > __this_cpu_sub(from->stat->count[idx], nr_pages); > __this_cpu_add(to->stat->count[idx], nr_pages); > - preempt_enable(); > } > > /** > -- > 1.8.5.3 > -- Michal Hocko SUSE Labs