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

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Date:   Mon, 7 Aug 2023 18:47:36 +0200
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Anna-Maria Behnsen <anna-maria@...utronix.de>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        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, Aug 7, 2023 at 5:38 PM Anna-Maria Behnsen
<anna-maria@...utronix.de> 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):
>
> 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 a lot for the data!

Can I add a Tested-by: tag from you to this series?