Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752561Ab2FKJEG (ORCPT ); Mon, 11 Jun 2012 05:04:06 -0400 Received: from e28smtp05.in.ibm.com ([122.248.162.5]:43451 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486Ab2FKJEB (ORCPT ); Mon, 11 Jun 2012 05:04:01 -0400 From: "Aneesh Kumar K.V" To: Michal Hocko 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 10/16] hugetlb/cgroup: Add the cgroup pointer to page lru In-Reply-To: <20120611081653.GB12402@tiehlicka.suse.cz> References: <1339232401-14392-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1339232401-14392-11-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <20120611081653.GB12402@tiehlicka.suse.cz> User-Agent: Notmuch/0.13.2+35~g0ff57e7 (http://notmuchmail.org) Emacs/24.1.50.1 (x86_64-unknown-linux-gnu) Date: Mon, 11 Jun 2012 14:33:52 +0530 Message-ID: <87oboq5ifb.fsf@skywalker.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain x-cbid: 12061109-8256-0000-0000-000002E03835 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4189 Lines: 142 Michal Hocko writes: > On Sat 09-06-12 14:29:55, Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V" >> >> Add the hugetlb cgroup pointer to 3rd page lru.next. > > Interesting and I really like the idea much more than tracking by > page_cgroup. > >> This limit the usage to hugetlb cgroup to only hugepages with 3 or >> more normal pages. I guess that is an acceptable limitation. > > Agreed. > >> Signed-off-by: Aneesh Kumar K.V > > Other than some nits I like this. > Thanks! > >> --- >> include/linux/hugetlb_cgroup.h | 31 +++++++++++++++++++++++++++++++ >> mm/hugetlb.c | 4 ++++ >> 2 files changed, 35 insertions(+) >> >> diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h >> index 5794be4..ceff1d5 100644 >> --- a/include/linux/hugetlb_cgroup.h >> +++ b/include/linux/hugetlb_cgroup.h >> @@ -26,6 +26,26 @@ struct hugetlb_cgroup { >> }; >> >> #ifdef CONFIG_CGROUP_HUGETLB_RES_CTLR >> +static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) >> +{ >> + if (!PageHuge(page)) >> + return NULL; >> + if (compound_order(page) < 3) > > Why 3? I think you wanted 2 here, right? Yes that should be 2. I updated that in an earlier. Already in v9 version I have locally. > >> + return NULL; >> + return (struct hugetlb_cgroup *)page[2].lru.next; >> +} >> + >> +static inline >> +int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) >> +{ >> + if (!PageHuge(page)) >> + return -1; >> + if (compound_order(page) < 3) > > Here as well. > >> + return -1; >> + page[2].lru.next = (void *)h_cg; >> + return 0; >> +} >> + >> static inline bool hugetlb_cgroup_disabled(void) >> { >> if (hugetlb_subsys.disabled) >> @@ -43,6 +63,17 @@ 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); >> #else >> +static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) >> +{ >> + return NULL; >> +} >> + >> +static inline >> +int set_hugetlb_cgroup(struct page *page, struct hugetlb_cgroup *h_cg) >> +{ >> + return 0; >> +} >> + >> static inline bool hugetlb_cgroup_disabled(void) >> { >> return true; >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index e899a2d..1ca2d8f 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -28,6 +28,7 @@ >> >> #include >> #include >> +#include >> #include >> #include "internal.h" >> >> @@ -591,6 +592,7 @@ static void update_and_free_page(struct hstate *h, struct page *page) >> 1 << PG_active | 1 << PG_reserved | >> 1 << PG_private | 1 << PG_writeback); >> } >> + BUG_ON(hugetlb_cgroup_from_page(page)); > > What about VM_BUG_ON? Will do, So when do one decide to choose VM_BUG_ON against BUG_ON ? > >> set_compound_page_dtor(page, NULL); >> set_page_refcounted(page); >> arch_release_hugepage(page); >> @@ -643,6 +645,7 @@ static void prep_new_huge_page(struct hstate *h, struct page *page, int nid) >> INIT_LIST_HEAD(&page->lru); >> set_compound_page_dtor(page, free_huge_page); >> spin_lock(&hugetlb_lock); >> + set_hugetlb_cgroup(page, NULL); > > Why inside the spin lock? All page[2].lru.next update is protected by hugetlb_lock . It should not really matter here, because the pages are not yet available to use. > >> h->nr_huge_pages++; >> h->nr_huge_pages_node[nid]++; >> spin_unlock(&hugetlb_lock); >> @@ -892,6 +895,7 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid) >> INIT_LIST_HEAD(&page->lru); >> r_nid = page_to_nid(page); >> set_compound_page_dtor(page, free_huge_page); >> + set_hugetlb_cgroup(page, NULL); >> /* >> * We incremented the global counters already >> */ >> -- -aneesh -- 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/