From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx157.postini.com [74.125.245.157]) by kanga.kvack.org (Postfix) with SMTP id 2B5266B004F for ; Thu, 19 Jan 2012 09:07:40 -0500 (EST) Date: Thu, 19 Jan 2012 15:07:37 +0100 From: Michal Hocko Subject: Re: [RFC] [PATCH 5/7 v2] memcg: remove PCG_FILE_MAPPED Message-ID: <20120119140737.GD13932@tiehlicka.suse.cz> References: <20120113173001.ee5260ca.kamezawa.hiroyu@jp.fujitsu.com> <20120113174223.aaf5a80c.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120113174223.aaf5a80c.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: "linux-mm@kvack.org" , Ying Han , "hugh.dickins@tiscali.co.uk" , "hannes@cmpxchg.org" , cgroups@vger.kernel.org, "bsingharora@gmail.com" On Fri 13-01-12 17:42:23, KAMEZAWA Hiroyuki wrote: > From a9b51d6204d7f8714173c46a306caf413ad25d4e Mon Sep 17 00:00:00 2001 > From: KAMEZAWA Hiroyuki > Date: Thu, 12 Jan 2012 18:40:26 +0900 > Subject: [PATCH 5/7] memcg: remove PCG_FILE_MAPPED > > Because we can update page's status and memcg's statistics without > race with move_account, this flag is unnecessary. I would really appreciate a little bit more description ;) 8725d541 [memcg: fix race in file_mapped accounting] has added the flag to resolve a race when a move_account happened between page's mapcount has been updated and this has been accounted to memcg. This, however, cannot happen anymore because mem_cgroup_update_page_stat is always enclosed by mem_cgroup_begin_update_page_stat and mem_cgroup_end_update_page_stat along with the mapcount update. > > Signed-off-by: KAMEZAWA Hiroyuki Other than that looks good and nice to see another one go away. I will add my ack along with the patches which this depend on once they settle down if you don't mind Thanks > --- > include/linux/page_cgroup.h | 6 ------ > mm/memcontrol.c | 6 +----- > 2 files changed, 1 insertions(+), 11 deletions(-) > > diff --git a/include/linux/page_cgroup.h b/include/linux/page_cgroup.h > index 5dba799..0b9a48a 100644 > --- a/include/linux/page_cgroup.h > +++ b/include/linux/page_cgroup.h > @@ -7,8 +7,6 @@ enum { > PCG_CACHE, /* charged as cache */ > PCG_USED, /* this object is in use. */ > PCG_MIGRATION, /* under page migration */ > - /* flags for mem_cgroup and file and I/O status */ > - PCG_FILE_MAPPED, /* page is accounted as "mapped" */ > __NR_PCG_FLAGS, > }; > > @@ -72,10 +70,6 @@ TESTPCGFLAG(Used, USED) > CLEARPCGFLAG(Used, USED) > SETPCGFLAG(Used, USED) > > -SETPCGFLAG(FileMapped, FILE_MAPPED) > -CLEARPCGFLAG(FileMapped, FILE_MAPPED) > -TESTPCGFLAG(FileMapped, FILE_MAPPED) > - > SETPCGFLAG(Migration, MIGRATION) > CLEARPCGFLAG(Migration, MIGRATION) > TESTPCGFLAG(Migration, MIGRATION) > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 30ef810..a96800d 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -1952,10 +1952,6 @@ void mem_cgroup_update_page_stat(struct page *page, > > switch (idx) { > case MEMCG_NR_FILE_MAPPED: > - if (val > 0) > - SetPageCgroupFileMapped(pc); > - else if (!page_mapped(page)) > - ClearPageCgroupFileMapped(pc); > idx = MEM_CGROUP_STAT_FILE_MAPPED; > break; > default: > @@ -2606,7 +2602,7 @@ static int mem_cgroup_move_account(struct page *page, > > mem_cgroup_account_move_wlock(page, &flags); > > - if (PageCgroupFileMapped(pc)) { > + if (page_mapcount(page)) { > /* Update mapped_file data for mem_cgroup */ > preempt_disable(); > __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); > -- > 1.7.4.1 > > > -- > 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org