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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DD4FC433EF for ; Wed, 3 Nov 2021 07:51:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D88CC60EBC for ; Wed, 3 Nov 2021 07:51:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230025AbhKCHyW (ORCPT ); Wed, 3 Nov 2021 03:54:22 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:14707 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230046AbhKCHyU (ORCPT ); Wed, 3 Nov 2021 03:54:20 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Hkf746QSQzZcgV for ; Wed, 3 Nov 2021 15:49:36 +0800 (CST) Received: from dggpemm500002.china.huawei.com (7.185.36.229) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 15:51:22 +0800 Received: from [10.174.179.5] (10.174.179.5) by dggpemm500002.china.huawei.com (7.185.36.229) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 15:51:22 +0800 Subject: Re: [Question]: questions about 'Use sysidle detection to let the timekeeper sleep' From: Xiongfeng Wang To: CC: Xie XiuQi , Linux Kernel Mailing List References: <93236de5-f76e-3915-bbdf-9d060435937a@huawei.com> Message-ID: <197f0d3a-dd7c-b90f-4a9d-8a21e289fd6b@huawei.com> Date: Wed, 3 Nov 2021 15:51:21 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <93236de5-f76e-3915-bbdf-9d060435937a@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.5] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500002.china.huawei.com (7.185.36.229) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sorry, I forgot to Cc the maillist again. Cc it in this mail. On 2021/11/3 10:59, Xiongfeng Wang wrote: > Hi Frederic, > > Sorry to disturb you. It's just that I came across the same problem as you > mentioned in the below link. > https://lwn.net/Articles/577424/ > > This is the problem in my situation. All the CPUs on my machine are in the same > power domain. When nohz_full is enabled, if one of the CPUs keep receiving tick > interrupts, all the CPUs can not be put into powerdown state, even thought all > other CPUs are idle. > > I found your first version patchset in the below link. > https://lore.kernel.org/lkml/1387320692-28460-1-git-send-email-fweisbec@gmail.com/ > But I couldn't found other verions. Even 'full-system-idle' is reverted in the > mailline in the following commit. > commit fe5ac724d81a3c7803e60c2232718f212f3f38d4 > rcu: Remove nohz_full full-system-idle state machine > > I am not sure if we have any other alternative solutions, or do we have rebased > the patchset to mainline kernel. The first version patchset I found is based on > v3.13. > > Thanks, > Xiongfeng >