From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RFT][PATCH v7 6/8] sched: idle: Select idle state before stopping the tick Date: Wed, 28 Mar 2018 12:56:42 +0200 Message-ID: References: <2390019.oHdSGtR3EE@aspire.rjw.lan> <2249320.0Z4q8AXauv@aspire.rjw.lan> <6462e44a-e207-6b97-22bf-ad4aed69afc2@tu-dresden.de> <4198010.6ArFqS34NK@aspire.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Thomas Ilsche , Peter Zijlstra , Linux PM , Frederic Weisbecker , Thomas Gleixner , Paul McKenney , Doug Smythies , Rik van Riel , Aubrey Li , Mike Galbraith , LKML List-Id: linux-pm@vger.kernel.org On Wed, Mar 28, 2018 at 12:37 PM, Rafael J. Wysocki wrote: > On Wed, Mar 28, 2018 at 10:38 AM, Thomas Ilsche > wrote: >> On 2018-03-28 10:13, Rafael J. Wysocki wrote: >>> [cut] > > So I do > > $ for cpu in 0 1 2 3; do taskset -c $cpu sh -c 'while true; do usleep > 500; done' & done > > which is a shell kind of imitation of the above and I cannot see this > issue at all. > > I count the number of times data->next_timer_us in menu_select() is > greater than TICK_USEC and while this "workload" is running, that > number is exactly 0. > > I'll try with a C program still. And with a C program I see data->next_timer_us greater than TICK_USEC while it is running, so let me dig deeper.