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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 EF4F3C43381 for ; Thu, 18 Mar 2021 11:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0C1264E61 for ; Thu, 18 Mar 2021 11:09:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230456AbhCRLJL (ORCPT ); Thu, 18 Mar 2021 07:09:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230408AbhCRLIk (ORCPT ); Thu, 18 Mar 2021 07:08:40 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A5C0C06174A for ; Thu, 18 Mar 2021 04:08:40 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id t20so1121201plr.13 for ; Thu, 18 Mar 2021 04:08:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=15LgLWnrDF9xrY/f9Qycq0PzYRn8kF+pr7olZciihDc=; b=KtCvKs+mdXNV7hiXR9LnggjmgOU3pD83nEi3aMALjUmJrnwc0VCJWtA33DzRM3ejR+ 8YCeNCjveM54mbqMhLrw7JP3SDAA/+rS/tHgOg0YaCpi3cyMXag0Dd61VsNKgMB2tvID 2b3pQVxuK/+w61Y4cHv1gZ2IyWU6+YiEJEGoFb3ThIPpM7fhElDTPdmC8c0tPj13uqN7 Cnc09uKri9MNkeloxXsBQiYNrzdIxFI+iQgNuZlIcQ/cYabVryhTdoTfUO6LWLt+9hxe LqHeBrO8JdxSUeNpZP/k85gDtzMZNOpwKW35Zg+IlzLlJg2zS4J2SFgP68SJqs4Lp1+l lemA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=15LgLWnrDF9xrY/f9Qycq0PzYRn8kF+pr7olZciihDc=; b=kE28qWpIWN8D2Grhs3wd+a6eWJIGWq0IRvl67VqqO3Z4RDzW3H1mmRBqbvIr8zhD7H PRJHXDwaFEJFgxxFwsD95klZviWe61UrKSgaNXlhGjQ4YOccw6IFdWb+TT+YlYfgeG6B Dy+Ggh/XMF17XBIzm11pz70KoW1z57uchUUbIfsd+OXlXE7dCJ4Mp870zROI+W35a/uQ w0T2KP0SDf24Fjn7WNcgvTlMgLJqOMC/6iH/3jAb8WOu/CF9HXA9NrhiWBE4sNLc0pj7 ufr60XmrSaUgAKHwPQV6Jao5y3mqDLBggwwV/sGZwJLSaFMGx0WoNidVC0AwEo1mqnBE JDLA== X-Gm-Message-State: AOAM532xaIcr/R2mS33hTeXLSVViTtcEkw6nug+lXJNhVrvRxrmEPDF7 mljquupJwgD+VMP/RHXocJipbQ== X-Google-Smtp-Source: ABdhPJwNlbzYvF2snPZSAkGAO2vl/mGld5g0amM9i3l7jk7w+k2UvRsVeWdXBYNJeKHXR8MS6D85HA== X-Received: by 2002:a17:90a:6e44:: with SMTP id s4mr3579552pjm.112.1616065720004; Thu, 18 Mar 2021 04:08:40 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.231]) by smtp.gmail.com with ESMTPSA id e21sm1779509pgv.74.2021.03.18.04.08.35 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 Mar 2021 04:08:39 -0700 (PDT) From: Muchun Song To: guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org, akpm@linux-foundation.org, shakeelb@google.com, vdavydov.dev@gmail.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, Muchun Song Subject: [PATCH v4 3/5] mm: memcontrol: change ug->dummy_page only if memcg changed Date: Thu, 18 Mar 2021 19:06:56 +0800 Message-Id: <20210318110658.60892-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.21.0 (Apple Git-122) In-Reply-To: <20210318110658.60892-1-songmuchun@bytedance.com> References: <20210318110658.60892-1-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fc22da9805fb..104bddf21314 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6845,6 +6845,7 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) uncharge_gather_clear(ug); } ug->memcg = page_memcg(page); + ug->dummy_page = page; /* pairs with css_put in uncharge_batch */ css_get(&ug->memcg->css); @@ -6858,7 +6859,6 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) else ug->pgpgout++; - ug->dummy_page = page; page->memcg_data = 0; css_put(&ug->memcg->css); } -- 2.11.0