From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by an-out-0708.google.com with SMTP id d17so78341and.105 for ; Thu, 26 Jun 2008 22:08:08 -0700 (PDT) Message-ID: <28c262360806262208i6791d67at446f7323ded16206@mail.gmail.com> Date: Fri, 27 Jun 2008 14:08:08 +0900 From: "MinChan Kim" Subject: Re: [-mm][PATCH 8/10] fix shmem page migration incorrectness on memcgroup In-Reply-To: <20080625190750.D864.KOSAKI.MOTOHIRO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080625185717.D84C.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080625190750.D864.KOSAKI.MOTOHIRO@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: LKML , linux-mm , Andrew Morton , Lee Schermerhorn , Rik van Riel , KOSAKI Motohiro , Daisuke Nishimura List-ID: Hi, KAMEZAWA-san. I have one question. It's just curious. On Wed, Jun 25, 2008 at 7:09 PM, KOSAKI Motohiro wrote: > > = > From: KAMEZAWA Hiroyuki > > mem_cgroup_uncharge() against old page is done after radix-tree-replacement. > And there were special handling to ingore swap-cache page. But, shmem can > be swap-cache and file-cache at the same time. Chekcing PageSwapCache() is > not correct here. Check PageAnon() instead. When/How shmem can be both swap-cache and file-cache ? I can't understand that situation. Thanks. :) > Signed-off-by: KAMEZAWA Hiroyuki > Acked-by: Daisuke Nishimura > Signed-off-by: KOSAKI Motohiro > > --- > mm/migrate.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > Index: b/mm/migrate.c > =================================================================== > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -332,7 +332,13 @@ static int migrate_page_move_mapping(str > __inc_zone_page_state(newpage, NR_FILE_PAGES); > > spin_unlock_irq(&mapping->tree_lock); > - if (!PageSwapCache(newpage)) > + > + /* > + * The page is removed from radix-tree implicitly. > + * We uncharge it here but swap cache of anonymous page should be > + * uncharged by mem_cgroup_ucharge_page(). > + */ > + if (!PageAnon(newpage)) > mem_cgroup_uncharge_cache_page(page); > > return 0; > @@ -381,7 +387,8 @@ static void migrate_page_copy(struct pag > /* > * SwapCache is removed implicitly. Uncharge against swapcache > * should be called after ClearPageSwapCache() because > - * mem_cgroup_uncharge_page checks the flag. > + * mem_cgroup_uncharge_page checks the flag. shmem's swap cache > + * is uncharged before here. > */ > mem_cgroup_uncharge_page(page); > } > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Kinds regards, MinChan Kim -- 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/ . Don't email: email@kvack.org