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=unavailable 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 597CFC433DB for ; Fri, 19 Mar 2021 01:23:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21CDC64E01 for ; Fri, 19 Mar 2021 01:23:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232441AbhCSBXC (ORCPT ); Thu, 18 Mar 2021 21:23:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232932AbhCSBWw (ORCPT ); Thu, 18 Mar 2021 21:22:52 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC3CEC06174A for ; Thu, 18 Mar 2021 18:22:51 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id n138so7517378lfa.3 for ; Thu, 18 Mar 2021 18:22:51 -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=CW4McI8JkV+pieEAOjNv+vlbnY5aNnNxkeeFzG0tW8w=; b=cDeKZHVFxabXMfipkJOP7Ibt7u7HVzssV//KJmna76gp11QpclpUxew/DscSIAVeT/ ILTnAIjHt4zXkV5rdRyMkftIzQhnm6/f4Fc1g/eFn3KcKwKdUaLvvXlCK9S6uSyQMJuy z8rnpEi1ijjr2S0a5dAwX48+eC9eYYzuuKyUyW8TWRdIdYlNVAScpyqUbBB+tzRz0DXp fwYpz0a0GpiFPVbBulejetQGfE9enAm6Qp3Az8rG1NCuJX/H5eajWjAZ3zEYkgbu4dGW 9z/ugj21ayFY1WgcWWhE9uw/ZP7lLMCb5UU9bvxnwru5IsOfv/1HtFzPEOaDcXXy7cUf fuhw== 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=CW4McI8JkV+pieEAOjNv+vlbnY5aNnNxkeeFzG0tW8w=; b=qly3HP+Hwnbc0HZJ9cmVPXBZuXJkyxsVJ3NTeX0sIG4jjxwD1IhXC8OcaACWEVhW+r t74MQP+H6PDqJ1pKw6NHsG2v84zrK5kvQTRpUjsu0E+cKlTVE7rFaYiqH0JXZ69FocjZ rsOCCnGStIkNCEnjPW+adSB/hyj/5K8n8RhWEWvK3xisiZ1uxGpof0Zhu6Aofarndm8v ktw8szcrzFpDrFf3+vx56T5afRIZI6KH/Y9rkzm/IeESJQnrBjs8h0doyty0GQtftUpr 8p4PTxsM3meXBvlZldFEjz0y/BIoz8P+ja+Z9znMqFAFvMXvE0iO1LqHU75SPXdy1fcQ iYTA== X-Gm-Message-State: AOAM533w9XKJrVtf6Dm6753W0PQbkRl0n+L/Yn1n7nkhdb9a8OUna2Y1 nmZWccZWC0EX1r71cko+1hO5q6JCrbMAtS54OvMRQnBIFk0= X-Google-Smtp-Source: ABdhPJyeKUzfk7qJwdmTpIOVyFefL4jP2HUWSjTzyZpGRUmli8dFZV88KSSE8oBfMULFwo4SPWZ4Um/djOyrGlRodTE= X-Received: by 2002:a19:ee19:: with SMTP id g25mr6696142lfb.83.1616116970201; Thu, 18 Mar 2021 18:22:50 -0700 (PDT) MIME-Version: 1.0 References: <20210318110658.60892-1-songmuchun@bytedance.com> <20210318110658.60892-4-songmuchun@bytedance.com> In-Reply-To: <20210318110658.60892-4-songmuchun@bytedance.com> From: Shakeel Butt Date: Thu, 18 Mar 2021 18:22:39 -0700 Message-ID: Subject: Re: [PATCH v4 3/5] mm: memcontrol: change ug->dummy_page only if memcg changed 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" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 18, 2021 at 4:08 AM Muchun Song wrote: > > Just like assignment to ug->memcg, we only need to update ug->dummy_page > if memcg changed. So move it to there. This is a very small optimization. > > Signed-off-by: Muchun Song Reviewed-by: Shakeel Butt