Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933925AbaDIPjm (ORCPT ); Wed, 9 Apr 2014 11:39:42 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.225]:50312 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933770AbaDIPj0 (ORCPT ); Wed, 9 Apr 2014 11:39:26 -0400 Date: Wed, 9 Apr 2014 11:39:23 -0400 From: Steven Rostedt To: Steven Rostedt Cc: Viresh Kumar , Thomas Gleixner , "Paul E. McKenney" , Matthew Whitehead , John Stultz , "linux-kernel@vger.kernel.org" , mwhitehe@redhat.com, Frederic Weisbecker Subject: Re: nohz problem with idle time on old hardware Message-ID: <20140409113923.7dcaf183@gandalf.local.home> In-Reply-To: <20140409113143.6174143f@gandalf.local.home> References: <20131113113927.GA13875@mwhitehe.csb> <20131113102153.5f10e6b5@gandalf.local.home> <20131113103134.5b8cf02f@gandalf.local.home> <20131113105737.3f7a0b1b@gandalf.local.home> <20131113111257.482c2955@gandalf.local.home> <20131113161829.GE4138@linux.vnet.ibm.com> <20131113112338.7d303c0f@gandalf.local.home> <20131113163552.GF4138@linux.vnet.ibm.com> <20140409103138.29be16b9@gandalf.local.home> <20140409112950.7be9f8ac@gandalf.local.home> <20140409113143.6174143f@gandalf.local.home> X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-RR-Connecting-IP: 107.14.168.142:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 9 Apr 2014 11:31:43 -0400 Steven Rostedt wrote: > > Hmm, looking at the code, I see it probably should still do the check. > > OK, nevermind ;-) Reading even more of the code, now I'm totally confused :-) When tick_setup_sched_timer() is called, if tick_nohz_enabled is set, then we set tick_nohz_active. This gets called by hrtimer_switch_to_hres(), and before that is called, the tick_check_oneshot_changed() will never get to the tick_nohz_switch_to_nohz() call. Looks to me, the real answer is to nuke both the if statement *and* the setting of the tick_nohz_active in that function. Both looks a bit redundant to me. -- Steve -- 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/