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

Anna-Maria Behnsen
2023-08-07T15:38:40Z

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On Thu, 3 Aug 2023, Rafael J. Wysocki wrote:

> On Thu, Aug 3, 2023 at 11:12 PM Rafael J. Wysocki <rjw@rjwysocki.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,

Anna-Maria