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[2620:137:e000::1:20]) by mx.google.com with ESMTP id c14-20020a17090a674e00b00232cc8a3603si4400465pjm.112.2023.02.10.01.58.12; Fri, 10 Feb 2023 01:58:25 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@shopee.com header.s=shopee.com header.b=LWCJXAT7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=shopee.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231774AbjBJJq2 (ORCPT + 99 others); Fri, 10 Feb 2023 04:46:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231379AbjBJJq0 (ORCPT ); Fri, 10 Feb 2023 04:46:26 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8756E64641 for ; Fri, 10 Feb 2023 01:46:25 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id gj9-20020a17090b108900b0023114156d36so8776409pjb.4 for ; Fri, 10 Feb 2023 01:46:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shopee.com; s=shopee.com; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=ppfFWpSAcZ1aESEIi3DI7xxDUI8KrBz5/PkXTDog9ro=; b=LWCJXAT7I+EECVCLtdt5TrDfY1jP64bH1PN4m10e5ID9k8mohRc90Id/D9P5YQ0zo8 tpNUNA/I+Y2qw21VFtzvbQq/iFU1JdeU5uWGqhcnZwqEX8DlWw+irAGC01fg4inhfNUj qfVuPkwbTvxBq/JFjbEKnDjL/vfK4QSLJHUBBrCzAQJAmSckmSmlND9nVCiYZS9FwxM7 +mUz9uyIMg8cibzSLzifH+bR9e0N1BIuhqHHXFjp60clgMKLA9obumlPzfdkCI9SomZS xSKsStJ8KUfMd4aBExGiaG0EOb+1TG/W36cWikejp1fQnLVQm6sVf36/6dWb00RBzrR7 nhUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=ppfFWpSAcZ1aESEIi3DI7xxDUI8KrBz5/PkXTDog9ro=; b=ztHhFiPz6/aC69ON41gV5kRo5CEKUvBp2DZJs3jmKnSOnK7AOxoS5SGgrkmEuHuXPX jqeJQ8tYqHf0COpWVo5qPwFAW/cN5RQFeAJTWiqEelPDlAa2Bl9idClJ3FEKO9JtWLxS N7OzoE8KDdB+XVaDnM2Igz9dIAzb0sD88dHCpyyHLFzx+Mvrefhd8gBxsGy9NyCuJKzJ oj5OnnCy7PdRcMPRhAhEToDZKMH3fhUevN26O/qXHxoQ/IMe3K//v1B7wKM7LBR+6e4Z ZQw8cct7aDRTArFjuN3HrEDTMCVxEnmTrtIsdG2LuHne1UIvdefm5DRgDwzFX2wcyIPa ZDHA== X-Gm-Message-State: AO0yUKWCLwxeVBfBSaFfdGnr+K7hH2bq7ewzlMymKICvwWSp/FOjpNQA jGrWY/RyCkwqChkQ0S+AdjtXag== X-Received: by 2002:a17:902:d48e:b0:199:472b:927f with SMTP id c14-20020a170902d48e00b00199472b927fmr10878196plg.51.1676022384998; Fri, 10 Feb 2023 01:46:24 -0800 (PST) Received: from ubuntu-haifeng.default.svc.cluster.local ([101.127.248.173]) by smtp.gmail.com with ESMTPSA id p11-20020a170902a40b00b0019460ac7c6asm2935186plq.283.2023.02.10.01.46.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Feb 2023 01:46:24 -0800 (PST) From: Haifeng Xu To: hannes@cmpxchg.org Cc: mhocko@kernel.org, shakeelb@google.com, muchun.song@linux.dev, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Haifeng Xu Subject: [PATCH] mm/memcg: Skip high limit check in root memcg Date: Fri, 10 Feb 2023 09:45:50 +0000 Message-Id: <20230210094550.5125-1-haifeng.xu@shopee.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1757437602930104803?= X-GMAIL-MSGID: =?utf-8?q?1757437602930104803?= The high limit checks the memory usage from given memcg to root memcg. However, there is no limit in root memcg. So this check makes no sense and we can ignore it. Signed-off-by: Haifeng Xu --- mm/memcontrol.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 73afff8062f9..a31a56598f29 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2780,6 +2780,10 @@ static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask, do { bool mem_high, swap_high; + /* There is no need for root memcg to check high limit */ + if (mem_cgroup_is_root(memcg)) + break; + mem_high = page_counter_read(&memcg->memory) > READ_ONCE(memcg->memory.high); swap_high = page_counter_read(&memcg->swap) >