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,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 086C4C43460 for ; Wed, 14 Apr 2021 17:50:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CADFB61177 for ; Wed, 14 Apr 2021 17:50:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350980AbhDNRuW (ORCPT ); Wed, 14 Apr 2021 13:50:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231452AbhDNRuV (ORCPT ); Wed, 14 Apr 2021 13:50:21 -0400 Received: from mail-qk1-x733.google.com (mail-qk1-x733.google.com [IPv6:2607:f8b0:4864:20::733]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5773CC061574 for ; Wed, 14 Apr 2021 10:49:59 -0700 (PDT) Received: by mail-qk1-x733.google.com with SMTP id 18so5437595qkl.3 for ; Wed, 14 Apr 2021 10:49:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=9Kzf8X1d0+K76SXVSOKe6DeC1BEbVx5t53APJl1jYBk=; b=POnNI+WsKl8yWcU4W+LDNHqNDo7rIIE4dL9tPELPmCbIsqYSnqdag4O0RIAljelvhp eq+lS+FtyrtaMGyhFasqes30iasqTw7p5i1j0roCRyjWE+H8DBmd8rZ/GauYjwT7kFmH orMvUAYZZx8wstflGyfL5XsbisPmORXC2Wso0gW4iTc2RoqG7vgQ0oU19IvIcOTgPWQr 5ykFGOwW3PfO+UxcdreKz5OYLsF6FjwIs0cFqQO3TIh0LpfoQNDpCL39gHRYjomyvogK 23GBNLbIh82nu6RoFq+6Dq/nnCHWyEBLDMViP5biVf9qCknrarWZkWiOg4PEx0V2YbTT Y0FQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9Kzf8X1d0+K76SXVSOKe6DeC1BEbVx5t53APJl1jYBk=; b=MeEBT7Zf3q+JFNf535MYqwgrqDEd7/W7ux/AsiBm2+r3vin7k6muQrDw0qj6TgIOAM F/RJ6ccJBsSIOd+QoGmILNbT7VLhk7dXEURNiUB6uE/pqKiLarI38AdmFi26lx++6fQ5 ofByXOVpnbyEUgzmGAvKAuHz+ACghku3qax1dLVcJZDK50fZbIbPr6gpiSgKe6vnStvJ tVu9fhYozU3AFkuDVyS0lPAtN0wPrDB0JhDWqxbeJscCDiEQtqXIVKoHHLi+Mk1GBZOu LeE5XZOC2ss2UMejd2WQzaboCVM2nZmpF8UZ2bci/V9CHVY7iTWEW1J2AC6Wtbd0L9zN z0Jw== X-Gm-Message-State: AOAM533mOSfo6npzMQqij0EfJIGuKcHz4JsWcOPXYm91uXhWL88Mxb89 ygQ0oNEPckcgDXWEpOzFRDM3OQ== X-Google-Smtp-Source: ABdhPJxIwsEzHtEQ2YHTLka9+4LLiJK+mXi8p25eVOfz6ij9Bj7WypO2+/GsCz+X1L85SxPZYCUyow== X-Received: by 2002:a37:6711:: with SMTP id b17mr26954820qkc.332.1618422598562; Wed, 14 Apr 2021 10:49:58 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::1:f8bd]) by smtp.gmail.com with ESMTPSA id h23sm59950qtr.21.2021.04.14.10.49.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Apr 2021 10:49:58 -0700 (PDT) Date: Wed, 14 Apr 2021 13:49:56 -0400 From: Johannes Weiner To: Muchun Song Cc: Michal Hocko , guro@fb.com, akpm@linux-foundation.org, shakeelb@google.com, vdavydov.dev@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, fam.zheng@bytedance.com Subject: Re: [External] Re: [PATCH 4/7] mm: memcontrol: simplify lruvec_holds_page_lru_lock Message-ID: References: <20210413065153.63431-1-songmuchun@bytedance.com> <20210413065153.63431-5-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 14, 2021 at 06:00:42PM +0800, Muchun Song wrote: > On Wed, Apr 14, 2021 at 5:44 PM Michal Hocko wrote: > > > > On Tue 13-04-21 14:51:50, Muchun Song wrote: > > > We already have a helper lruvec_memcg() to get the memcg from lruvec, we > > > do not need to do it ourselves in the lruvec_holds_page_lru_lock(). So use > > > lruvec_memcg() instead. And if mem_cgroup_disabled() returns false, the > > > page_memcg(page) (the LRU pages) cannot be NULL. So remove the odd logic > > > of "memcg = page_memcg(page) ? : root_mem_cgroup". And use lruvec_pgdat > > > to simplify the code. We can have a single definition for this function > > > that works for !CONFIG_MEMCG, CONFIG_MEMCG + mem_cgroup_disabled() and > > > CONFIG_MEMCG. > > > > Neat. While you are at it wouldn't it make sesne to rename the function > > as well. I do not want to bikeshed but this is really a misnomer. it > > doesn't check anything about locking. page_belongs_lruvec? > > Right. lruvec_holds_page_lru_lock is used to check whether > the page belongs to the lruvec. page_belongs_lruvec > obviously more clearer. I can rename it to > page_belongs_lruvec the next version. This sounds strange to me, I think 'belongs' needs a 'to' to be correct, so page_belongs_to_lruvec(). Still kind of a mouthful. page_matches_lruvec()? page_from_lruvec()?