From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751960AbdJPFfE (ORCPT ); Mon, 16 Oct 2017 01:35:04 -0400 Received: from mga09.intel.com ([134.134.136.24]:40500 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751246AbdJPFfA (ORCPT ); Mon, 16 Oct 2017 01:35:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,385,1503385200"; d="scan'208";a="163031647" Subject: Re: [RFC PATCH v2 4/8] tick/nohz: keep tick on for a fast idle To: Mike Galbraith , "Rafael J. Wysocki" , Aubrey Li Cc: tglx@linutronix.de, peterz@infradead.org, len.brown@intel.com, ak@linux.intel.com, tim.c.chen@linux.intel.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org References: <1506756034-6340-1-git-send-email-aubrey.li@intel.com> <1506756034-6340-5-git-send-email-aubrey.li@intel.com> <4523111.uMcC96MW3N@aspire.rjw.lan> <5beefd1a-2792-c371-3bb8-8ee2a6574020@linux.intel.com> <1508129104.8087.2.camel@gmx.de> From: "Li, Aubrey" Message-ID: Date: Mon, 16 Oct 2017 13:34:57 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <1508129104.8087.2.camel@gmx.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/10/16 12:45, Mike Galbraith wrote: > On Mon, 2017-10-16 at 11:26 +0800, Li, Aubrey wrote: >> >> I'll try to move quiet_vmstat() into the normal idle branch if this patch series >> are reasonable. Is fast_idle a good indication for it? > > see x86_tip 62cb1188ed86 sched/idle: Move quiet_vmstate() into the NOHZ code It looks like this commit makes tick stop critical as it can be invoked in interrupt exit path? ->smp_apic_timer_interrupt -->irq_exit --->tick_nohz_irq_exit ---->__tick_nohz_idle_enter ----->tick_nohz_stop_sched_tick ------>quiet_vmstat Thanks, -Aubrey