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 AE926C4707A for ; Tue, 5 Apr 2022 10:51:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235496AbiDEKwy (ORCPT ); Tue, 5 Apr 2022 06:52:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345995AbiDEJoQ (ORCPT ); Tue, 5 Apr 2022 05:44:16 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6E5C6EC2; Tue, 5 Apr 2022 02:29:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BC980616B6; Tue, 5 Apr 2022 09:29:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C02CFC385A4; Tue, 5 Apr 2022 09:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649150993; bh=f7lk/uatWZehCCEatvm6qnumEhlCGUuUHdGZqbrb3Fw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OYHu23M/P8LgKmDUonyIo8DyaS7veL0Knj4HdzUyOhupWOE6LM4FqiBVGdeOyDBlU 46/sZ8UVU00xQUO+eqea/6UJ2uyiz/ZFCFmzhxGIZWyC3mzl0Lu3YSawqowfEUyTYZ E+VBB/UYmJVgN0pcuXkTnrHbhcfXUEytuTn2+UDY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Minye Zhu , Chengming Zhou , "Peter Zijlstra (Intel)" , Tejun Heo , Sasha Levin Subject: [PATCH 5.15 256/913] sched/cpuacct: Fix charge percpu cpuusage Date: Tue, 5 Apr 2022 09:21:58 +0200 Message-Id: <20220405070347.528824559@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070339.801210740@linuxfoundation.org> References: <20220405070339.801210740@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chengming Zhou [ Upstream commit 248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd ] 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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Tejun Heo Link: https://lore.kernel.org/r/20220220051426.5274-1-zhouchengming@bytedance.com Signed-off-by: Sasha Levin --- 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 ab67d97a8442..cacc2076ad21 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -328,12 +328,13 @@ 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(); } -- 2.34.1