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=-18.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=ham 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 7A007C433E0 for ; Fri, 19 Mar 2021 01:01:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F057F64DDF for ; Fri, 19 Mar 2021 01:01:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F057F64DDF Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 691F46B006E; Thu, 18 Mar 2021 21:01:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 62F386B0071; Thu, 18 Mar 2021 21:01:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D0216B0072; Thu, 18 Mar 2021 21:01:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0211.hostedemail.com [216.40.44.211]) by kanga.kvack.org (Postfix) with ESMTP id 2E6386B006E for ; Thu, 18 Mar 2021 21:01:46 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id E6620181BF8A7 for ; Fri, 19 Mar 2021 01:01:45 +0000 (UTC) X-FDA: 77934821370.33.004323A Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com [209.85.167.41]) by imf09.hostedemail.com (Postfix) with ESMTP id 9B2236000110 for ; Fri, 19 Mar 2021 01:00:40 +0000 (UTC) Received: by mail-lf1-f41.google.com with SMTP id n138so7457404lfa.3 for ; Thu, 18 Mar 2021 18:00:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AT07gM1d/snjyMuDSqF2iBtIXpjEUy5a43Ltdcejjg4=; b=KM6wA1h7XMgkD3D79Vjsw2MmDWvfXJ31KEsqyx2fIBaUvQGNEqgs6PpaVuPo3zKImT Q3tiRKlgQ9AUuBHHTBLPq17XL96zfVNc4/DfUrqyy6ZjSJeIre8PkiAezAxIMnTOk/ib mikaQN9tKxbtsEjCV7/vZJTSd+UzINRP34wFQqGixick42qAE3kFIBSAyoYYUsMtvzuh IsKjzY860tn7jQE8vSWi41A90uiZjxHqdgDT1yeoTS+wp84b5EYtwmyCsG2IJxD6lQ2Y /CqaoK5eGrqUrIOVqw5eeOPef+Rj7XuoWsuM1ytcZnfyZQFQnV+KsHD7Or1RXsgem1pM lBEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AT07gM1d/snjyMuDSqF2iBtIXpjEUy5a43Ltdcejjg4=; b=ZsyYlmGSV9LZ4RqYz1RJRTCPXQiOH8G+Fb+aKcbIjxya6OzjkNAkCAofUE0fotorsH FuI+2kV/NKZDm8AW+Wbz+SOq75YbaegqexO0o9Q4e+qNCcMQGXsX67SlVFEdzsEjFDID mslk7UEHOQ4rBHQPnka2Xatpfo1O0Z5NuSITsvAbvYZJsQgn32ueGAunZBMggIXFuxCy 9lqFI4PCZvpT7gMwmj0bFqTF7a9Utwpj1NTmmLbLFwWox4JyPEmAHRLoWVjfQExIa+yp IxwMK869CDObyym+wsD4KSWLVQ/yvaSgZa+U3IY4J5afaLhK8Q1pj9pfINU8zCzznB5D CgAQ== X-Gm-Message-State: AOAM532isuxSzXNNEyGjs5FjAaM0y/8gUD22G3PSRVYFUF1cYOErdKkB WF8BIkKLg7TwP8PjEVuyAxGP+Bl6bl8NJqZsfZuWTA== X-Google-Smtp-Source: ABdhPJyAoTNzchIV4OsZupLeZBjHgM/VDsLdpg0/QqJnmE/7url1KCv7Er5GJi7lYwqVehF2EnRm9gV0C+awyzWwObg= X-Received: by 2002:a19:c14a:: with SMTP id r71mr6731527lff.358.1616115638843; Thu, 18 Mar 2021 18:00:38 -0700 (PDT) MIME-Version: 1.0 References: <20210318110658.60892-1-songmuchun@bytedance.com> <20210318110658.60892-3-songmuchun@bytedance.com> In-Reply-To: <20210318110658.60892-3-songmuchun@bytedance.com> From: Shakeel Butt Date: Thu, 18 Mar 2021 18:00:27 -0700 Message-ID: Subject: Re: [PATCH v4 2/5] mm: memcontrol: directly access page->memcg_data in mm/page_alloc.c To: Muchun Song Cc: Roman Gushchin , Johannes Weiner , Michal Hocko , Andrew Morton , Vladimir Davydov , LKML , Linux MM , Xiongchun duan Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: hx69kzge8w5947b6d5hxjyzjqer4uis4 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 9B2236000110 Received-SPF: none (google.com>: No applicable sender policy available) receiver=imf09; identity=mailfrom; envelope-from=""; helo=mail-lf1-f41.google.com; client-ip=209.85.167.41 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616115640-186265 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Mar 18, 2021 at 4:08 AM Muchun Song wrote: > > The page_memcg() is not suitable for use by page_expected_state() and > page_bad_reason(). Because it can BUG_ON() for the slab pages when > CONFIG_DEBUG_VM is enabled. As neither lru, nor kmem, nor slab page > should have anything left in there by the time the page is freed, what > we care about is whether the value of page->memcg_data is 0. So just > directly access page->memcg_data here. > > Signed-off-by: Muchun Song Reviewed-by: Shakeel Butt