Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753562AbbGSMbr (ORCPT ); Sun, 19 Jul 2015 08:31:47 -0400 Received: from mx2.parallels.com ([199.115.105.18]:47430 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753368AbbGSMbl (ORCPT ); Sun, 19 Jul 2015 08:31:41 -0400 From: Vladimir Davydov To: Andrew Morton CC: Andres Lagar-Cavilla , Minchan Kim , Raghavendra K T , Johannes Weiner , Michal Hocko , Greg Thelen , Michel Lespinasse , David Rientjes , Pavel Emelyanov , Cyrill Gorcunov , Jonathan Corbet , , , , , Subject: [PATCH -mm v9 1/8] memcg: add page_cgroup_ino helper Date: Sun, 19 Jul 2015 15:31:10 +0300 Message-ID: X-Mailer: git-send-email 2.1.4 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.24.25.231] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2246 Lines: 66 This function returns the inode number of the closest online ancestor of the memory cgroup a page is charged to. It is required for exporting information about which page is charged to which cgroup to userspace, which will be introduced by a following patch. Signed-off-by: Vladimir Davydov Reviewed-by: Andres Lagar-Cavilla --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index d92b80b63c5c..99b0e43cac45 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -345,6 +345,7 @@ static inline bool mm_match_cgroup(struct mm_struct *mm, } struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page); +unsigned long page_cgroup_ino(struct page *page); static inline bool mem_cgroup_disabled(void) { diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 1def8810880a..a91bc1ee964c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -441,6 +441,29 @@ struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) return &memcg->css; } +/** + * page_cgroup_ino - return inode number of the memcg a page is charged to + * @page: the page + * + * Look up the closest online ancestor of the memory cgroup @page is charged to + * and return its inode number or 0 if @page is not charged to any cgroup. It + * is safe to call this function without holding a reference to @page. + */ +unsigned long page_cgroup_ino(struct page *page) +{ + struct mem_cgroup *memcg; + unsigned long ino = 0; + + rcu_read_lock(); + memcg = READ_ONCE(page->mem_cgroup); + while (memcg && !(memcg->css.flags & CSS_ONLINE)) + memcg = parent_mem_cgroup(memcg); + if (memcg) + ino = cgroup_ino(memcg->css.cgroup); + rcu_read_unlock(); + return ino; +} + static struct mem_cgroup_per_zone * mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page) { -- 2.1.4 -- 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/