From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC14FC2D0A3 for ; Sat, 7 Nov 2020 01:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 866BB20867 for ; Sat, 7 Nov 2020 01:30:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604712617; bh=5ja+hHDhLaw834klWxEIsEobJjKzEYlU1fK3r77mU5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=EqeijvoeFndNhhg9z9ZJ2wF6m4SxlJsR/SIIdMUiSTQCLgoLgksJU0mXuFLgIc3Hy tEFSZQEqSGxCvJuXmhCFDzjcei2AWDj4rw4mG7PDkmD9X4x4fdsyG+imj+eJBLP1CV 4Ty1p/J+JI4kYAgLpppnCjQhKnutUazHSi8+3leg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728408AbgKGBaQ (ORCPT ); Fri, 6 Nov 2020 20:30:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:47326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727129AbgKGBaQ (ORCPT ); Fri, 6 Nov 2020 20:30:16 -0500 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1E9F320720; Sat, 7 Nov 2020 01:30:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604712615; bh=5ja+hHDhLaw834klWxEIsEobJjKzEYlU1fK3r77mU5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jZrN5F7/+Zu3GmPA5iLrAhldT/HnmmgsyZF2eKJZ9aZUKndfgBlXBzDVBKRlKB20J gnoQgoeBoM9JlKv5BRD526px7a20WshtiPv/94Md18VkK2B5uF32W2PcQAXlnjhxJP wyfF6u9yfTq52lPBu14DkQlLqPNi719Z1w4wjAJ4= Date: Fri, 6 Nov 2020 17:30:14 -0800 From: Andrew Morton To: Hui Su Cc: hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, shakeelb@google.com, guro@fb.com, laoar.shao@gmail.com, chris@chrisdown.name, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] mm/memcontrol:rewrite mem_cgroup_page_lruvec() Message-Id: <20201106173014.e13b5fe5edec41d1f7fdf072@linux-foundation.org> In-Reply-To: <20201104142516.GA106571@rlk> References: <20201104142516.GA106571@rlk> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Nov 2020 22:25:16 +0800 Hui Su wrote: > mem_cgroup_page_lruvec() in memcontrol.c and > mem_cgroup_lruvec() in memcontrol.h is very similar > except for the param(page and memcg) which also can be > convert to each other. > > So rewrite mem_cgroup_page_lruvec() with mem_cgroup_lruvec(). Alex Shi's "mm/memcg: warning on !memcg after readahead page charged" (https://lkml.kernel.org/r/1604283436-18880-3-git-send-email-alex.shi@linux.alibaba.com) changes mem_cgroup_page_lruvec() thusly: --- a/mm/memcontrol.c~mm-memcg-warning-on-memcg-after-readahead-page-charged +++ a/mm/memcontrol.c @@ -1325,10 +1325,7 @@ struct lruvec *mem_cgroup_page_lruvec(st } memcg = page_memcg(page); - /* - * Swapcache readahead pages are added to the LRU - and - * possibly migrated - before they are charged. - */ + VM_WARN_ON_ONCE_PAGE(!memcg, page); if (!memcg) memcg = root_mem_cgroup; So the patch didn't apply. That's easily fixed, but it does make one wonder whether this: > -struct lruvec *mem_cgroup_page_lruvec(struct page *, struct pglist_data *); > +/** > + * mem_cgroup_page_lruvec - return lruvec for isolating/putting an LRU page > + * @page: the page > + * @pgdat: pgdat of the page > + * > + * This function relies on page->mem_cgroup being stable. > + */ > +static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, > + struct pglist_data *pgdat) > +{ > + struct mem_cgroup *memcg = page->mem_cgroup; > + > + return mem_cgroup_lruvec(memcg, pgdat); > +} Should be using page_memcg()?