From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751579AbbAVLHN (ORCPT ); Thu, 22 Jan 2015 06:07:13 -0500 Received: from 7of9.schinagl.nl ([88.159.158.68]:47544 "EHLO 7of9.schinagl.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750811AbbAVLHH (ORCPT ); Thu, 22 Jan 2015 06:07:07 -0500 Message-ID: <54C0D9D7.4010903@ultimaker.com> Date: Thu, 22 Jan 2015 12:07:03 +0100 From: Olliver Schinagl Organization: Ultimaker B.V. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Thomas Gleixner CC: linux-kernel@vger.kernel.org, Olliver Schinagl Subject: Re: [PATCH] hrtimer: add hrtimer_start_now() References: <1421907161-5744-1-git-send-email-o.schinagl@ultimaker.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey Thomas, On 22-01-15 12:01, Thomas Gleixner wrote: > On Thu, 22 Jan 2015, Olliver Schinagl wrote: > >> From: Olliver Schinagl >> >> When using a hrtimer for repeating periodic ticks, hrtimer_forward_now() >> is often used. Quite possibly the timer loop is thus probably fully >> controlled by hrtimer_forward_now() and we don't really care when the >> timer is started. With hrtimer_start() we need to define exactly when a >> event has to start. By introducing hrtimer_start_now() we do the same as >> what hrtimer_forward_now() does, start as soon as possible and get into >> the timer loop. > >> Signed-off-by: Olliver Schinagl >> --- >> include/linux/hrtimer.h | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h >> index a036d05..080a5f5 100644 >> --- a/include/linux/hrtimer.h >> +++ b/include/linux/hrtimer.h >> @@ -353,6 +353,12 @@ static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } >> /* Basic timer operations: */ >> extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, >> const enum hrtimer_mode mode); >> + >> +static inline int hrtimer_start_now(struct hrtimer *timer, >> + const enum hrtimer_mode mode) >> +{ >> + return hrtimer_start(timer, timer->base->get_time(), mode); >> +} > What's the mode argument for? How is this supposed to do what you > want: > > hrtimer_start_now(timer, HRTIMER_MODE_REL); Ah, of course, I guess we'd have to use a fixed default, my bad. > > Aside of that, what's wrong with doing: > > static const ktime_t ktime_zero = { .tv64 = 0 }; > > hrtimer_start(timer, ktime_zero, HRTIMER_MODE_REL); I guess the same could be said for hrtimer_forward_now I suppose. It was just intended as a little helper, with emphasis on helper. Olliver > > Thanks, > > tglx -- Met vriendelijke groeten, Kind regards, 与亲切的问候 Olliver Schinagl Research & Development Ultimaker B.V. http://www.ultimaker.com