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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3848DC433EF for ; Sun, 20 Feb 2022 05:15:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230511AbiBTFQI (ORCPT ); Sun, 20 Feb 2022 00:16:08 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:46552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbiBTFPo (ORCPT ); Sun, 20 Feb 2022 00:15:44 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0C81F44775 for ; Sat, 19 Feb 2022 21:15:24 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id q1so1756603plx.4 for ; Sat, 19 Feb 2022 21:15:23 -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=pDzj7KZknHyouw/r6qE4vjgFR7kon3SsiF5AQBFK5Gw=; b=EFzLVl5Ix1bXx0C5RFyXdcz9Swcll0Zadz/75SV0gqKiGcE5XUTNNXtq9oNbfhzZ23 1K5JYnaeWCSXUdH/8TZ3CCpsNQ2PukgmrZTfFSJ/6gTFSOzJyvkNeyT6anVqCEgYtnCx gJ4w8E5uGRgKMfSMeXX0RUk+1EzKnVMDlMyg24QnXxGZsY4zwgn+Tcqy+j4mD060gnWy 4SkUXrCkCE8+4wy8JPqxdv65pskmaYXPtS8mi6ITuyMu6rqM9adwq2UYIVlIEL6NcL6x A+ozfsSVlnXlYDV9sBw+XHL8BRMs1veUccFYwQung4Ps7Dt0NB4Rk3SAwx3OeJL5Cdk6 cxeA== 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=pDzj7KZknHyouw/r6qE4vjgFR7kon3SsiF5AQBFK5Gw=; b=eHagkyc64BMqB9ADpRmlsWD4lFnVRNFa2L1WZStTQuG1wJjlE1brZ/AAGoJp83KNsG C4qYlPo0msPf6XB+ofhQk96yp3QKxz2Hl5OP/xYPSS54EHt6YR9tX70BkzTrsdj8ARRy KdGFJRgnt856khvNqUuQXgFierrqFqqmsqQq2MyFzHRUxPSsV7CutJNMClZ2LdZwyLGq XtLuxPN/TaXOyc3b7h/g+Cbywn8PRDjg5Q9XiAQY2qvsXwP1/bN6PQJHRDKkDLfGnLqq j574R813+5cutKBcDUYtLUiorb6/GMs/lYYYZPGtPKrET6RFNXgXU095NwDAZHTjJCti Osyg== X-Gm-Message-State: AOAM531M9KdGGRo4eEobc2KQTcUoEn5v1xwp1G2GW6hLcIThC9TiZeRU XHlFHfF11HtAZQ/Q29IzelkF8g== X-Google-Smtp-Source: ABdhPJzStZ5RaSbbvogMa/4zlhfjcCdnWmX8k5xjzbsDd67FoFMiQSOOChplCLzarh1NSzmb99VwTA== X-Received: by 2002:a17:90b:4d11:b0:1b8:b502:d190 with SMTP id mw17-20020a17090b4d1100b001b8b502d190mr19911800pjb.27.1645334123411; Sat, 19 Feb 2022 21:15:23 -0800 (PST) Received: from localhost.localdomain ([2409:8a28:e61:5860:2995:483c:273c:28ec]) by smtp.gmail.com with ESMTPSA id y23sm7737907pfa.67.2022.02.19.21.15.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Feb 2022 21:15:22 -0800 (PST) From: Chengming Zhou To: mingo@redhat.com, peterz@infradead.org, vincent.guittot@linaro.org, bristot@redhat.com, zhaolei@cn.fujitsu.com, tj@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org Cc: linux-kernel@vger.kernel.org, Chengming Zhou , Minye Zhu Subject: [PATCH v3 1/3] sched/cpuacct: fix charge percpu cpuusage Date: Sun, 20 Feb 2022 13:14:24 +0800 Message-Id: <20220220051426.5274-1-zhouchengming@bytedance.com> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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..307800586ac8 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -334,12 +334,13 @@ static struct cftype files[] = { */ void cpuacct_charge(struct task_struct *tsk, u64 cputime) { + unsigned int cpu = task_cpu(tsk); struct cpuacct *ca; rcu_read_lock(); for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) - __this_cpu_add(*ca->cpuusage, cputime); + *per_cpu_ptr(ca->cpuusage, cpu) += cputime; rcu_read_unlock(); } -- 2.20.1