Re: [RFT] [PATCH v1] cpuidle: menu: Skip tick_nohz_get_sleep_length() call in some cases

[Doug Smythies]

On Wed, Aug 9, 2023 at 11:16 AM Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
> On Wed, Aug 9, 2023 at 4:53 PM Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> >
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Because the cost of calling tick_nohz_get_sleep_length() may increase
> > in the future, reorder the code in menu_select() so it first uses the
> > statistics to determine the expected idle duration.  If that value is
> > higher than RESIDENCY_THRESHOLD_NS, tick_nohz_get_sleep_length() will
> > be called to obtain the time till the closest timer and refine the
> > idle duration prediction if necessary.
> >
> > This causes the governor to always take the full overhead of
> > get_typical_interval() with the assumption that the cost will be
> > amortized by skipping the tick_nohz_get_sleep_length() call in the
> > cases when the predicted idle duration is relatively very small.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > ---
... deleted...
>
> This patch is now present in the git branch at
>
> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \
>  pm-cpuidle-gov
>
> along with the previous teo governor changes.

Hi Rafael,

Thanks for the branch and adding it to the previous 6.5-rc4 code,
as now I can re-use the menu baseline tests already done.

My test computer boots by default to use the teo idle governor.
When I change to the menu governor, my system becomes
unresponsive and I have to re-boot.

Is anyone else having this difficulty?

... Doug