From nobody Sun Jun 28 02:50:34 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 1A7A4C433EF for ; Tue, 15 Feb 2022 12:52:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237956AbiBOMwS (ORCPT ); Tue, 15 Feb 2022 07:52:18 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:56044 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232616AbiBOMwQ (ORCPT ); Tue, 15 Feb 2022 07:52:16 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DF671AF2A for ; Tue, 15 Feb 2022 04:52:06 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id om7so17311479pjb.5 for ; Tue, 15 Feb 2022 04:52:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=M4vOG1MxIcvAeIUiKHRfizxs2Ti0mOYROHB7Jdcc1G0=; b=FlVko+8xIgFVOZG5EwFzWNjkKIG1XeNaQKgP8zS7KdfKbcf4CXI4Xcs4H82OGFyVDg UmfUvZbQT3hPMfC00YtmvC0nQrK9UdYdpjBrGNgJBDvkDTI4ywv5qmh2tIdPmifH6vC/ zlvunXnrDklwPDDh+t1/qZ802BPpVNxWssBkRtXxpzqU9K4/rotCBr69G6/yZZQS4vl1 9h1sA7Wan/LUTcUq7mY75MVrKzzPpS6WWJnibwjS+oW5nqmEi2UZSut8iiAsxZe8SIXs t1ChQGqPqo7JV9HT/8Wd9g3LS4nlZs14JfW76UdKkTjEtOTtYceWH+RmqrP47H7LvOG/ aJ4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=M4vOG1MxIcvAeIUiKHRfizxs2Ti0mOYROHB7Jdcc1G0=; b=7GtH58xZ9Gjrdw3o/gDSE+CMZzia/CBcldAgaJVm7wSsEI/xtdw+vivDL9STcTPI4U bgE4u06EzoNcWPU1g5pUe99Orq8/I2FShuuXnM4e/c3BH2UBAK544nS6D/tsDJFLMWvR k6r6bfBcotQeDoG/CjWrIO7sP8PgDX/FmSBFrhWriSX9NThhjDw0EFMdbqXlPj0N0Ag/ 7AMh3jONJMPLuI+DdpcIqxxdEJWKeigBQ2RCGKFUFUzXzeYB5p6rT2p6xf4loT6xAhS/ T7E+s+7s1ufzt7tgmAgWxELrsUgLHZEMBaAiERKJd+p3S4JikGUSVA0OuEDqXt1V7WMk Jlug== X-Gm-Message-State: AOAM532+kPKBR9iMwJkbo8HFjtfqbPB9MVY0x42TG3ZS3RrBrp/tjR5X Z4fQQRRrhJz5uvUAYU6dccQd5g== X-Google-Smtp-Source: ABdhPJzGgZIzImzhFzA6LpGu+vqxtNbu6DH6NDgvnUsjY1XzvgGw4rpM8skk9KBzneHLkNZJfP6SnA== X-Received: by 2002:a17:902:b692:: with SMTP id c18mr4102998pls.85.1644929526212; Tue, 15 Feb 2022 04:52:06 -0800 (PST) Received: from C02CV1DAMD6P.bytedance.net ([139.177.225.230]) by smtp.gmail.com with ESMTPSA id x126sm25580764pfb.117.2022.02.15.04.52.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Feb 2022 04:52:05 -0800 (PST) From: Chengming Zhou To: peterz@infradead.org, tj@kernel.org Cc: linux-kernel@vger.kernel.org, Chengming Zhou , Minye Zhu Subject: [PATCH v2] sched/cpuacct: fix charge percpu cpuusage Date: Tue, 15 Feb 2022 20:51:57 +0800 Message-Id: <20220215125157.78386-1-zhouchengming@bytedance.com> X-Mailer: git-send-email 2.35.1 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" The cpuacct_account_field() is always called by the current task itself, so it's ok to use __this_cpu_add() to charge the tick time. But cpuacct_charge() maybe called by update_curr() in load_balance() on a random CPU, different from the CPU on which the task is running. So __this_cpu_add() will charge that cputime to a random incorrect CPU. Fixes: 73e6aafd9ea8 ("sched/cpuacct: Simplify the cpuacct code") Reported-by: Minye Zhu Signed-off-by: Chengming Zhou --- kernel/sched/cpuacct.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 3d06c5e4220d..75fbc212cb71 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -335,11 +335,12 @@ static struct cftype files[] =3D { void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; + unsigned int cpu =3D task_cpu(tsk); =20 rcu_read_lock(); =20 for (ca =3D task_ca(tsk); ca; ca =3D parent_ca(ca)) - __this_cpu_add(*ca->cpuusage, cputime); + *per_cpu_ptr(ca->cpuusage, cpu) +=3D cputime; =20 rcu_read_unlock(); } --=20 2.20.1