From nobody Sat May 10 02:34:19 2025 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail(p=none dis=none) header.from=linux.alibaba.com ARC-Seal: i=1; a=rsa-sha256; t=1606446558; cv=none; d=zohomail.com; s=zohoarc; b=XheXdcDAMXu4RPB094WPVKNpN9IDN+a/B17WxV2ppywNQmzbIFTKls/yaM8p5Arm1A7HqAA2yQtf4G4eGD8/q6NUDybDnkQktcUARqpIGt8BQimEbkMbaJ2e6tkYIzmOap51zMIZndaer2NUfBh8oOsCpwhbxZSNJYFXdlELgTo= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1606446558; h=Cc:Date:From:List-Id:Message-ID:Subject:To; bh=C4NQCcoJMnO/o8IdrZdta87f7WabyHGxI2hwK3ZD4vs=; b=Zc9nXOg3ieWieHQnHUxtS0x4CGkK+ydN1vcGFpLVZiiVC7PraL2+lzQG+c23JxMX/KWvPtQdCyUFiXPdqhR+3jjMUaxwHslhS3lXQeIRAYdCrOyIt1S0p1VoNDbSfxcR6dfAMqLdhaLOuW1cBo497880o5v+Q42G/KXK2mluzj4= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 1606446558511161.06428988597906; Thu, 26 Nov 2020 19:09:18 -0800 (PST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392295AbgK0DIm (ORCPT ); Thu, 26 Nov 2020 22:08:42 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:60086 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392286AbgK0DIm (ORCPT ); Thu, 26 Nov 2020 22:08:42 -0500 Received: from aliy80.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0UGebCV9_1606446518) by smtp.aliyun-inc.com(127.0.0.1); Fri, 27 Nov 2020 11:08:38 +0800 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R441e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04420;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0UGebCV9_1606446518; From: Alex Shi Cc: Andrew Morton , Johannes Weiner , Shakeel Butt , Roman Gushchin , Lorenzo Stoakes , Stephen Rothwell , Alexander Duyck , Yafang Shao , Wei Yang , linux-kernel@vger.kernel.org Subject: [PATCH] mm/memcg: bail out early when !memcg in mem_cgroup_lruvec Date: Fri, 27 Nov 2020 11:08:35 +0800 Message-Id: <1606446515-36069-1-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sometime, we use NULL memcg in mem_cgroup_lruvec(memcg, pgdat) so we could get out early in the situation to avoid useless checking. Also warning if both parameter are NULL. Signed-off-by: Alex Shi Cc: Andrew Morton Cc: Johannes Weiner Cc: Shakeel Butt Cc: Roman Gushchin Cc: Lorenzo Stoakes Cc: Stephen Rothwell Cc: Alexander Duyck Cc: Yafang Shao Cc: Wei Yang Cc: linux-kernel@vger.kernel.org --- include/linux/memcontrol.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 3e6a1df3bdb9..4cdb110f84e0 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -613,14 +613,13 @@ static inline struct lruvec *mem_cgroup_lruvec(struct= mem_cgroup *memcg, struct mem_cgroup_per_node *mz; struct lruvec *lruvec; =20 - if (mem_cgroup_disabled()) { + VM_WARN_ON_ONCE(!memcg && !pgdat); + + if (mem_cgroup_disabled() || !memcg) { lruvec =3D &pgdat->__lruvec; goto out; } =20 - if (!memcg) - memcg =3D root_mem_cgroup; - mz =3D mem_cgroup_nodeinfo(memcg, pgdat->node_id); lruvec =3D &mz->lruvec; out: --=20 2.29.GIT