Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932380Ab3E3N5f (ORCPT ); Thu, 30 May 2013 09:57:35 -0400 Received: from www.linutronix.de ([62.245.132.108]:33516 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932199Ab3E3N51 (ORCPT ); Thu, 30 May 2013 09:57:27 -0400 Date: Thu, 30 May 2013 15:57:17 +0200 (CEST) From: Thomas Gleixner To: Frederic Weisbecker cc: Ingo Molnar , LKML , Jiri Bohac , Steven Rostedt , "Paul E. McKenney" , Peter Zijlstra , Borislav Petkov Subject: Re: [PATCH] nohz: Prevent broadcast source from stealing full dynticks timekeeping duty In-Reply-To: <1369845580-15273-2-git-send-email-fweisbec@gmail.com> Message-ID: References: <1369845580-15273-1-git-send-email-fweisbec@gmail.com> <1369845580-15273-2-git-send-email-fweisbec@gmail.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1058 Lines: 31 On Wed, 29 May 2013, Frederic Weisbecker wrote: > The timekeeping duty is currently assigned to the CPU that > handles the tick broadcast clock device by the time it is set in > one shot mode. > > The reason for this is not entirely clear as outlined by Jiri > Bohac: https://patchwork.kernel.org/patch/2302951/ > > One could speculate though that it makes sure only one CPU > is woken up to fixup the timekeeping max deferment. But the > timekeeper can change anytime after the broadcast CPU becomes > idle. So probably we can remove this as in Jiri's patch, but > not late in the -rc's. Looking at commit 7300711e (clockevents: broadcast fixup possible waiters) which introduced that takeover, I really can't see a reason why we must do that. It's safe to remove it completely even now. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/