From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx159.postini.com [74.125.245.159]) by kanga.kvack.org (Postfix) with SMTP id 6C9D66B004D for ; Wed, 25 Jan 2012 08:36:57 -0500 (EST) Date: Wed, 25 Jan 2012 14:36:45 +0100 From: Johannes Weiner Subject: Re: [PATCH v5] memcg: remove PCG_CACHE page_cgroup flag Message-ID: <20120125133645.GC7694@cmpxchg.org> References: <20120120084545.GC9655@tiehlicka.suse.cz> <20120124121636.115f1cf0.kamezawa.hiroyu@jp.fujitsu.com> <20120124111644.GE1660@cmpxchg.org> <20120124145411.GF1660@cmpxchg.org> <20120124160140.GH26289@tiehlicka.suse.cz> <20120124164449.GH1660@cmpxchg.org> <20120124172308.GI26289@tiehlicka.suse.cz> <20120124180842.GA18372@tiehlicka.suse.cz> <20120125090025.6d24cd0f.kamezawa.hiroyu@jp.fujitsu.com> <20120125144100.4fcfcb82.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120125144100.4fcfcb82.kamezawa.hiroyu@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: KAMEZAWA Hiroyuki Cc: Michal Hocko , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , Hugh Dickins , Ying Han On Wed, Jan 25, 2012 at 02:41:00PM +0900, KAMEZAWA Hiroyuki wrote: > Subject: [PATCH v5] memcg: remove PCG_CACHE > > We record 'the page is cache' by PCG_CACHE bit to page_cgroup. > Here, "CACHE" means anonymous user pages (and SwapCache). This > doesn't include shmem. > > Consdering callers, at charge/uncharge, the caller should know > what the page is and we don't need to record it by using 1bit > per page. > > This patch removes PCG_CACHE bit and make callers of > mem_cgroup_charge_statistics() to specify what the page is. > > About page migration: > Mapping of the used page is not touched during migration (see > page_remove_rmap) so we can rely on it and push the correct charge type > down to __mem_cgroup_uncharge_common from end_migration for unused page. > The force flag was misleading was abused for skipping the needless > page_mapped() / PageCgroupMigration() check, as we know the unused page > is no longer mapped and cleared the migration flag just a few lines > up. But doing the checks is no biggie and it's not worth adding another > flag just to skip them. > > Changelog since v4 > - fixed a bug at page migration by Michal Hokko. > > Changelog since v3 > - renamed a variable 'rss' to 'anon' > > Changelog since v2 > - removed 'not_rss', added 'anon' > - changed a meaning of arguments to mem_cgroup_charge_statisitcs() > - removed a patch to mem_cgroup_uncharge_cache > - simplified comment. > > Changelog since RFC. > - rebased onto memcg-devel > - rename 'file' to 'not_rss' > - some cleanup and added comment. > > Signed-off-by: KAMEZAWA Hiroyuki Acked-by: Johannes Weiner -- 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