linux-kernel - Re: [RFT][PATCH v2 0/3] cpuidle: teo: Do not check timers unconditionally every time

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Message-ID: <44a36b57-92cd-e3fd-da1d-367450c76010@linutronix.de>
Date:   Mon, 7 Aug 2023 17:39:27 +0200 (CEST)
From:   Anna-Maria Behnsen <anna-maria@...utronix.de>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
cc:     Linux PM <linux-pm@...r.kernel.org>,
        Kajetan Puchalski <kajetan.puchalski@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Frederic Weisbecker <frederic@...nel.org>
Subject: Re: [RFT][PATCH v2 0/3] cpuidle: teo: Do not check timers unconditionally
 every time

On Mon, 7 Aug 2023, Anna-Maria Behnsen wrote:

> On Thu, 3 Aug 2023, Rafael J. Wysocki wrote:
> 
> > On Thu, Aug 3, 2023 at 11:12 PM Rafael J. Wysocki <rjw@...ysocki.net> wrote:
> > >
> > > Hi Folks,
> > >
> > > This is the second iteration of:
> > >
> > > https://lore.kernel.org/linux-pm/4511619.LvFx2qVVIh@kreacher/
> > >
> > > with an additional patch.
> > >
> > > There are some small modifications of patch [1/3] and the new
> > > patch causes governor statistics to play a role in deciding whether
> > > or not to stop the scheduler tick.
> > >
> > > Testing would be much appreciated!
> > 
> > For convenience, this series is now available in the following git branch:
> > 
> > git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \
> >  pm-cpuidle-teo
> > 
> 
> Gauthams tests and the distribution of idle time durations looks pretty
> good. Also the prevention of calling tick_nohz_get_sleep_length() is very
> nice (21477 calls of tick_nohz_next_event() and the tick was stopped 2670
> times).
> 
> Here is the deviation of idle time durations (based on your branch):

Sorry, s/deviation/distribution

> Idle Total		2670	100.00%
> x >= 4ms		2537	95.02%
> 4ms> x >= 2ms		19	0.71%
> 2ms > x >= 1ms		10	0.37%
> 1ms > x >= 500us	7	0.26%
> 500us > x >= 250us	6	0.22%
> 250us > x >=100us	13	0.49%
> 100us > x >= 50us	17	0.64%
> 50us > x >= 25us	25	0.94%
> 25us > x >= 10us	22	0.82%
> 10us > x > 5us		9	0.34%
> 5us > x			5	0.19%
> 
> 
> Thanks,
> 
> 	Anna-Maria