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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AAA9C433E6 for ; Mon, 28 Dec 2020 07:55:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34BCA221F9 for ; Mon, 28 Dec 2020 07:55:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726423AbgL1Hyz (ORCPT ); Mon, 28 Dec 2020 02:54:55 -0500 Received: from szxga01-in.huawei.com ([45.249.212.187]:4125 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726282AbgL1Hyz (ORCPT ); Mon, 28 Dec 2020 02:54:55 -0500 Received: from dggeme756-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4D48tf4cW4zXsnv; Mon, 28 Dec 2020 15:53:30 +0800 (CST) Received: from [10.174.177.103] (10.174.177.103) by dggeme756-chm.china.huawei.com (10.3.19.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Mon, 28 Dec 2020 15:54:12 +0800 Subject: can the idle value of /proc/stat decrease? From: "xuqiang (M)" To: , , , , Andrew Morton , , CC: References: <1ad49a62-41dd-cdcc-2f8c-b7a2ad67c3b6@huawei.com> Message-ID: Date: Mon, 28 Dec 2020 15:54:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <1ad49a62-41dd-cdcc-2f8c-b7a2ad67c3b6@huawei.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.103] X-ClientProxiedBy: dggeme719-chm.china.huawei.com (10.1.199.115) To dggeme756-chm.china.huawei.com (10.3.19.102) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Our recent test shows that the idle value of /proc/stat can decrease. Is this an unreported bug? or it has been reported and the solution is waiting to get merged. The results of the two readings from /proc/stat are shown as below, the interval between the two readings is 150 ms: cat /proc/stat cpu0 5536 10 14160 4118960 0 0 227128 0 0 0 cat /proc/stat cpu0 5536 10 14160 4118959 0 0 227143 0 0 0