From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753256Ab3LRKGa (ORCPT ); Wed, 18 Dec 2013 05:06:30 -0500 Received: from merlin.infradead.org ([205.233.59.134]:41960 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751443Ab3LRKG2 (ORCPT ); Wed, 18 Dec 2013 05:06:28 -0500 Date: Wed, 18 Dec 2013 11:06:15 +0100 From: Peter Zijlstra To: Frederic Weisbecker Cc: LKML , Thomas Gleixner , Ingo Molnar , Steven Rostedt , "Paul E. McKenney" , John Stultz , Alex Shi , Kevin Hilman Subject: Re: [PATCH 07/13] sched: Enable IPI reception on timekeeper under nohz full system Message-ID: <20131218100615.GN13532@twins.programming.kicks-ass.net> References: <1387320692-28460-1-git-send-email-fweisbec@gmail.com> <1387320692-28460-8-git-send-email-fweisbec@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1387320692-28460-8-git-send-email-fweisbec@gmail.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 17, 2013 at 11:51:26PM +0100, Frederic Weisbecker wrote: > We need the default timekeeping CPU to be able to receive IPIs sent > from full dynticks CPUs when they wake up from full system idle state. > > Therefore we need an entrypoint from the scheduler IPI so that the > need to poll on timekeeping duty is re-evaluated from irq_exit(). > > In order to achieve this, lets take the scheduler IPI everytime as long > as there is at least one full dynticks CPU around. Full dynticks CPUs > are interested too in taking scheduler IPIs to reevaluate their tick. I should probably read the other patches in this series, but the above makes my brain go *beeeep* and throw an error.