From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Li, Aubrey" Subject: Re: [RFC PATCH v2 4/8] tick/nohz: keep tick on for a fast idle Date: Mon, 16 Oct 2017 13:34:57 +0800 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1508129104.8087.2.camel@gmx.de> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: linux-pm@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