From nobody Sat Apr 11 21:30:05 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35604C19F2D for ; Sat, 6 Aug 2022 12:05:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230322AbiHFMFi (ORCPT ); Sat, 6 Aug 2022 08:05:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230237AbiHFMFe (ORCPT ); Sat, 6 Aug 2022 08:05:34 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB513BC2F for ; Sat, 6 Aug 2022 05:05:32 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id r22so2321350pgm.5 for ; Sat, 06 Aug 2022 05:05:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=YOlS/iS0J/nVVMYG59d7cm+gvfjMBzPJ2apUEsXMO+g=; b=qfSdy6v02mjjdS8Q0pT4G9yvbvrNWq2FGR06bdigqXC5PRhi6ELcVQ6S1SnTjj0pAy Ka0oHnEZ3uBkv0zaaz0Yr8xzty+mB9YTCxOsYtP2dyLvmayWwo1r/y9fQi6cr+mFak0c 5/ulIenQioWkccproU3qQN/y3kmPa5xFAjaYHWZ75H2GoQ0bkxiSCjiJ+Dum+zo/AkTo RzxPN+haSDPzfGKk3vb5eBc59TaGVz22u9iRv//EH3EmyXqh0yJQYv33lp8YwqsPQ12X rQcFX1leHWO9CHu2uKm3Nxu3Hb5tSwKRqXeIvTYYhJwIgvknuPG1kvofz1u+QpwuTgXV 45XA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=YOlS/iS0J/nVVMYG59d7cm+gvfjMBzPJ2apUEsXMO+g=; b=vb/qfa4Uv8qDpQ3480v8FuXCJnW951m5kGBtWo/VQ/yziYvYGFcemPl6tkSwPiBZAq I1ZxFdBzn8TzEo0VB5AIjVRdgse4UqkxcEZKae4RZK1Xq1HhwlBWdFIQ1UldcQDijxTj 6IgnjQ+nA+eVBvLBHIddd3M95qCCYMwfSOjjblZeWIl6XGebdto6z4IOE5j7hDE9THZl 5uG4lE402hGikuANS7jfOWYx3DorU9B9s5TYAiyCIVDQWEf4TVPVUuI8iJ/AtU5Q2XwL 30w+JsIXD8HgcvTSUCgsiM9sJ+Ql8n15dKRVy6nPSkyv5a4+4Vynif0XNnQCOUqIV3Bc Xl9g== X-Gm-Message-State: ACgBeo1StpBieNjBmwfQXuON1rj1/vwzBnk9uhylJI5pqVwfMcUyVYYf XOjIqeyz346uawQ4LmHR0WnrAA== X-Google-Smtp-Source: AA6agR4Q19KRI9nbznHC8ED3ZwWBdPi2gytzXkoWcJfdWjhH3nz/wh2FttimVj5xAqes0EN4Miur5w== X-Received: by 2002:a05:6a00:32cb:b0:52e:2756:3558 with SMTP id cl11-20020a056a0032cb00b0052e27563558mr10895099pfb.59.1659787532333; Sat, 06 Aug 2022 05:05:32 -0700 (PDT) Received: from C02G87K0MD6R.bytedance.net ([139.177.225.228]) by smtp.gmail.com with ESMTPSA id t4-20020a63eb04000000b003db7de758besm3035003pgh.5.2022.08.06.05.05.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 06 Aug 2022 05:05:31 -0700 (PDT) From: Hao Jia To: mingo@redhat.com, peterz@infradead.org, mingo@kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com Cc: linux-kernel@vger.kernel.org, Hao Jia Subject: [PATCH 1/3] sched/psi: Zero the memory of struct psi_group Date: Sat, 6 Aug 2022 20:05:08 +0800 Message-Id: <20220806120510.96131-2-jiahao.os@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220806120510.96131-1-jiahao.os@bytedance.com> References: <20220806120510.96131-1-jiahao.os@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" After commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default"), the memory used by struct psi_group is no longer allocated and zeroed in cgroup_create(). Since the memory of struct psi_group is not zeroed, the data in this memory is random, which will lead to inaccurate psi statistics when creating a new cgroup. So we use kzlloc() to allocate and zero the struct psi_group and remove the redundant zeroing in group_init(). Steps to reproduce: 1. Use cgroup v2 and enable CONFIG_PSI 2. Create a new cgroup, and query psi statistics mkdir /sys/fs/cgroup/test cat /sys/fs/cgroup/test/cpu.pressure some avg10=3D0.00 avg60=3D0.00 avg300=3D47927752200.00 total=3D12884901 full avg10=3D561815124.00 avg60=3D125835394188.00 avg300=3D1077090462000.00= total=3D10273561772 cat /sys/fs/cgroup/test/io.pressure some avg10=3D1040093132823.95 avg60=3D1203770351379.21 avg300=3D38622526695= 59.46 total=3D4294967296 full avg10=3D921884564601.39 avg60=3D0.00 avg300=3D1984507298.35 total=3D44= 2381631 cat /sys/fs/cgroup/test/memory.pressure some avg10=3D232476085778.11 avg60=3D0.00 avg300=3D0.00 total=3D0 full avg10=3D0.00 avg60=3D0.00 avg300=3D2585658472280.57 total=3D12884901 Fixes: commit 5f69a6577bc3 ("psi: dont alloc memory for psi by default") Signed-off-by: Hao Jia Acked-by: Johannes Weiner --- kernel/sched/psi.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index ec66b40bdd40..5ee615a59fe1 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -190,12 +190,8 @@ static void group_init(struct psi_group *group) /* Init trigger-related members */ mutex_init(&group->trigger_lock); INIT_LIST_HEAD(&group->triggers); - memset(group->nr_triggers, 0, sizeof(group->nr_triggers)); - group->poll_states =3D 0; group->poll_min_period =3D U32_MAX; - memset(group->polling_total, 0, sizeof(group->polling_total)); group->polling_next_update =3D ULLONG_MAX; - group->polling_until =3D 0; init_waitqueue_head(&group->poll_wait); timer_setup(&group->poll_timer, poll_timer_fn, 0); rcu_assign_pointer(group->poll_task, NULL); @@ -957,7 +953,7 @@ int psi_cgroup_alloc(struct cgroup *cgroup) if (static_branch_likely(&psi_disabled)) return 0; =20 - cgroup->psi =3D kmalloc(sizeof(struct psi_group), GFP_KERNEL); + cgroup->psi =3D kzalloc(sizeof(struct psi_group), GFP_KERNEL); if (!cgroup->psi) return -ENOMEM; =20 --=20 2.32.0