From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755797Ab3F1R27 (ORCPT ); Fri, 28 Jun 2013 13:28:59 -0400 Received: from mail-pa0-f53.google.com ([209.85.220.53]:61129 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755184Ab3F1R26 (ORCPT ); Fri, 28 Jun 2013 13:28:58 -0400 Message-ID: <51CDC7D6.9070804@gmail.com> Date: Fri, 28 Jun 2013 11:28:54 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Peter Zijlstra CC: Ingo Molnar , LKML Subject: Re: deadlock in scheduler enabling HRTICK feature References: <51CA0622.8010105@gmail.com> <20130625211713.GA18796@laptop.programming.kicks-ass.net> <51CA0980.8010409@gmail.com> <20130626070533.GA3601@dyad.programming.kicks-ass.net> <51CB1AE9.5090709@gmail.com> <20130627104309.GQ28407@twins.programming.kicks-ass.net> <51CCBCA9.1000200@gmail.com> <20130628090939.GD29209@dyad.programming.kicks-ass.net> In-Reply-To: <20130628090939.GD29209@dyad.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/28/13 3:09 AM, Peter Zijlstra wrote: > Yah! :-) Obviously doing a wakeup while holding scheduler locks isn't going to > work out well. And the only reason we really need that pesky softirq nonsense > is when we accidentally schedule a timer that's already expired; in that case > we'll run it from sirq context. > > We don't care about missing events like that; there's always the actual tick > for backup. > > I suppose I'd better go write a Changelog and properly submit the patch :-) > Thanks for the quick turnaround on the patch - and the explanation. David