From patchwork Mon Apr 6 19:57:59 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tejun Heo X-Patchwork-Id: 6165161 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id A77BA9F1BE for ; Mon, 6 Apr 2015 20:16:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C943220303 for ; Mon, 6 Apr 2015 20:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 917B8202EC for ; Mon, 6 Apr 2015 20:16:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753345AbbDFT7h (ORCPT ); Mon, 6 Apr 2015 15:59:37 -0400 Received: from mail-qc0-f176.google.com ([209.85.216.176]:32941 "EHLO mail-qc0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753102AbbDFT7I (ORCPT ); Mon, 6 Apr 2015 15:59:08 -0400 Received: by qcrf4 with SMTP id f4so15093792qcr.0; Mon, 06 Apr 2015 12:59:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=OLi+Jl8rAvTAmjC1jeZ+tLj5SIk308oHoDZJOBmgDYo=; b=khaRkNN9o8PenLqAhS69OYztllXbBTunUk7UsBVrX3uUYT9ZQVY/IokMBPVYiHJ6gI l7NdcMX6Rupm8Yjk86Orsm0PhHq+fl8CgEITiMgToYdqAt7CtsWdGLEAQjNHqbQ1Ac8E i5DnESh0Co1ANtzjHjIVM/1cB9pKSQLKnmCCbFu+Rpje0//8nvm3QKxV/L2XA0XURGQv yrL2bmLgNpeYcIIhBXOYoTNaaTGFkIo27M3cLetfT6vaqyRDOtK5pXD7te75bagfvl4U pyXNeV75WBm/Ah3uq9TaGhsX77RO/Bc6aHwubEMyAOJFfdNoUjqkzulgfLuP4lPxfEef 6XVg== X-Received: by 10.229.14.74 with SMTP id f10mr20102374qca.10.1428350347826; Mon, 06 Apr 2015 12:59:07 -0700 (PDT) Received: from htj.duckdns.org.lan (207-38-238-8.c3-0.wsd-ubr1.qens-wsd.ny.cable.rcn.com. [207.38.238.8]) by mx.google.com with ESMTPSA id z67sm3914418qgz.10.2015.04.06.12.59.06 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Apr 2015 12:59:06 -0700 (PDT) From: Tejun Heo To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, Tejun Heo Subject: [PATCH 10/49] memcg: implement mem_cgroup_css_from_page() Date: Mon, 6 Apr 2015 15:57:59 -0400 Message-Id: <1428350318-8215-11-git-send-email-tj@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1428350318-8215-1-git-send-email-tj@kernel.org> References: <1428350318-8215-1-git-send-email-tj@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Implement mem_cgroup_css_from_page() which returns the cgroup_subsys_state of the memcg associated with a given page. This will be used by cgroup writeback support. Signed-off-by: Tejun Heo Cc: Johannes Weiner Cc: Michal Hocko --- include/linux/memcontrol.h | 1 + mm/memcontrol.c | 14 ++++++++++++++ 2 files changed, 15 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 294498f..637ef62 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -115,6 +115,7 @@ static inline bool mm_match_cgroup(struct mm_struct *mm, } extern struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg); +extern struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page); struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *, struct mem_cgroup *, diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fda7025..74241b3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -591,6 +591,20 @@ struct cgroup_subsys_state *mem_cgroup_css(struct mem_cgroup *memcg) return &memcg->css; } +/** + * mem_cgroup_css_from_page - css of the memcg associated with a page + * @page: page of interest + * + * This function is guaranteed to return a valid cgroup_subsys_state and + * the returned css remains accessible until @page is released. + */ +struct cgroup_subsys_state *mem_cgroup_css_from_page(struct page *page) +{ + if (page->mem_cgroup) + return &page->mem_cgroup->css; + return &root_mem_cgroup->css; +} + static struct mem_cgroup_per_zone * mem_cgroup_page_zoneinfo(struct mem_cgroup *memcg, struct page *page) {