From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859Ab2GJGVN (ORCPT ); Tue, 10 Jul 2012 02:21:13 -0400 Received: from cantor2.suse.de ([195.135.220.15]:46604 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753101Ab2GJGVM (ORCPT ); Tue, 10 Jul 2012 02:21:12 -0400 Date: Tue, 10 Jul 2012 08:21:04 +0200 From: Michal Hocko To: Wanpeng Li Cc: Johannes Weiner , Andrew Morton , KAMEZAWA Hiroyuki , Hugh Dickins , David Rientjes , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [patch 08/11] mm: memcg: remove needless !mm fixup to init_mm when charging Message-ID: <20120710062104.GA19223@tiehlicka.suse.cz> References: <1341449103-1986-1-git-send-email-hannes@cmpxchg.org> <1341449103-1986-9-git-send-email-hannes@cmpxchg.org> <20120709152058.GK4627@tiehlicka.suse.cz> <20120710061021.GA6096@kernel> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120710061021.GA6096@kernel> 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 Tue 10-07-12 14:10:21, Wanpeng Li wrote: > On Mon, Jul 09, 2012 at 05:20:58PM +0200, Michal Hocko wrote: > >On Thu 05-07-12 02:45:00, Johannes Weiner wrote: > >> It does not matter to __mem_cgroup_try_charge() if the passed mm is > >> NULL or init_mm, it will charge the root memcg in either case. > > You can also change the comment in __mem_cgroup_try_charge : > > "if so charge the init_mm" => "if so charge the root memcg" This is already in place: " If mm is NULL and the caller doesn't pass a valid memcg pointer, that is treated as a charge to root_mem_cgroup. " > > >> > >> Signed-off-by: Johannes Weiner > > > >Acked-by: Michal Hocko > > > >> --- > >> mm/memcontrol.c | 5 ----- > >> 1 files changed, 0 insertions(+), 5 deletions(-) > >> > >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c > >> index 418b47d..6fe4101 100644 > >> --- a/mm/memcontrol.c > >> +++ b/mm/memcontrol.c > >> @@ -2766,8 +2766,6 @@ int mem_cgroup_try_charge_swapin(struct mm_struct *mm, > >> ret = 0; > >> return ret; > >> charge_cur_mm: > >> - if (unlikely(!mm)) > >> - mm = &init_mm; > >> ret = __mem_cgroup_try_charge(mm, mask, 1, memcgp, true); > >> if (ret == -EINTR) > >> ret = 0; > >> @@ -2832,9 +2830,6 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, > >> if (PageCompound(page)) > >> return 0; > >> > >> - if (unlikely(!mm)) > >> - mm = &init_mm; > >> - > >> if (!PageSwapCache(page)) > >> ret = mem_cgroup_charge_common(page, mm, gfp_mask, type); > >> else { /* page is swapcache/shmem */ > >> -- > >> 1.7.7.6 > >> > > > >-- > >Michal Hocko > >SUSE Labs > >SUSE LINUX s.r.o. > >Lihovarska 1060/12 > >190 00 Praha 9 > >Czech Republic > >-- > >To unsubscribe from this list: send the line "unsubscribe cgroups" in > >the body of a message to majordomo@vger.kernel.org > >More majordomo info at http://vger.kernel.org/majordomo-info.html -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic