From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755572AbcAOIKU (ORCPT ); Fri, 15 Jan 2016 03:10:20 -0500 Received: from mail-wm0-f53.google.com ([74.125.82.53]:36654 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752397AbcAOIKS (ORCPT ); Fri, 15 Jan 2016 03:10:18 -0500 Subject: Re: [RFC 4/8] Improve the tracking of active utilisation To: Peter Zijlstra References: <1452785094-3086-1-git-send-email-luca.abeni@unitn.it> <1452785094-3086-5-git-send-email-luca.abeni@unitn.it> <20160114194752.GD6357@twins.programming.kicks-ass.net> Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Juri Lelli From: Luca Abeni Message-ID: <5698A967.5050300@unitn.it> Date: Fri, 15 Jan 2016 09:10:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20160114194752.GD6357@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/14/2016 08:47 PM, Peter Zijlstra wrote: > On Thu, Jan 14, 2016 at 04:24:49PM +0100, Luca Abeni wrote: > >> + if (!hrtimer_is_queued(timer)) { >> + hrtimer_start(timer, act, HRTIMER_MODE_ABS); >> + } >> + >> + if (hrtimer_active(timer) == 0) { >> + printk("Problem activating inactive_timer!\n"); >> + clear_running_bw(dl_se, dl_rq); >> + if (!dl_task(p)) { >> + __dl_clear_params(p); >> + } >> + } else { >> + get_task_struct(p); > > Ah, I missed that one. I would suggest putting that right _before_ > hrtimer_start(), because hrtimer_start() guarantees the callback will > run. Ok. So, if I understand well, the "if (hrtimer_active(timer) == 0)" check is useless (or should be somehow revised)... Right? Thanks, Luca