Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753349Ab2FKJY1 (ORCPT ); Mon, 11 Jun 2012 05:24:27 -0400 Received: from cantor2.suse.de ([195.135.220.15]:41636 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753152Ab2FKJY0 (ORCPT ); Mon, 11 Jun 2012 05:24:26 -0400 Date: Mon, 11 Jun 2012 11:24:24 +0200 From: Michal Hocko To: "Aneesh Kumar K.V" Cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, dhillf@gmail.com, rientjes@google.com, akpm@linux-foundation.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org Subject: Re: [PATCH -V8 15/16] hugetlb/cgroup: migrate hugetlb cgroup info from oldpage to new page during migration Message-ID: <20120611092424.GJ12402@tiehlicka.suse.cz> References: <1339232401-14392-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339232401-14392-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1339232401-14392-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com> 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 Content-Length: 3473 Lines: 115 On Sat 09-06-12 14:30:00, Aneesh Kumar K.V wrote: > From: "Aneesh Kumar K.V" > > With HugeTLB pages, hugetlb cgroup is uncharged in compound page > destructor. Since we are holding a hugepage reference, Who is holding that reference? I do not see anybody calling get_page in this patch... > we can be sure that old page won't get uncharged till the last > put_page(). > > Signed-off-by: Aneesh Kumar K.V > --- > include/linux/hugetlb_cgroup.h | 8 ++++++++ > mm/hugetlb_cgroup.c | 21 +++++++++++++++++++++ > mm/migrate.c | 5 +++++ > 3 files changed, 34 insertions(+) > > diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h > index ba4836f..b64d067 100644 > --- a/include/linux/hugetlb_cgroup.h > +++ b/include/linux/hugetlb_cgroup.h > @@ -63,6 +63,8 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, > extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, > struct hugetlb_cgroup *h_cg); > extern int hugetlb_cgroup_file_init(int idx) __init; > +extern void hugetlb_cgroup_migrate(struct page *oldhpage, > + struct page *newhpage); > #else > static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) > { > @@ -112,5 +114,11 @@ static inline int __init hugetlb_cgroup_file_init(int idx) > { > return 0; > } > + > +static inline void hugetlb_cgroup_migrate(struct page *oldhpage, > + struct page *newhpage) > +{ > + return; > +} > #endif /* CONFIG_MEM_RES_CTLR_HUGETLB */ > #endif > diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c > index c2b7b8e..2d384fe 100644 > --- a/mm/hugetlb_cgroup.c > +++ b/mm/hugetlb_cgroup.c > @@ -394,6 +394,27 @@ int __init hugetlb_cgroup_file_init(int idx) > return 0; > } > > +void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) > +{ > + struct hugetlb_cgroup *h_cg; > + > + VM_BUG_ON(!PageHuge(oldhpage)); > + > + if (hugetlb_cgroup_disabled()) > + return; > + > + spin_lock(&hugetlb_lock); > + h_cg = hugetlb_cgroup_from_page(oldhpage); > + set_hugetlb_cgroup(oldhpage, NULL); > + cgroup_exclude_rmdir(&h_cg->css); > + > + /* move the h_cg details to new cgroup */ > + set_hugetlb_cgroup(newhpage, h_cg); > + spin_unlock(&hugetlb_lock); > + cgroup_release_and_wakeup_rmdir(&h_cg->css); > + return; > +} > + > struct cgroup_subsys hugetlb_subsys = { > .name = "hugetlb", > .create = hugetlb_cgroup_create, > diff --git a/mm/migrate.c b/mm/migrate.c > index fdce3a2..6c37c51 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -33,6 +33,7 @@ > #include > #include > #include > +#include > #include > > #include > @@ -931,6 +932,10 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, > > if (anon_vma) > put_anon_vma(anon_vma); > + > + if (!rc) > + hugetlb_cgroup_migrate(hpage, new_hpage); > + > unlock_page(hpage); > out: > put_page(new_hpage); > -- > 1.7.10 > -- 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 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/