[RFD] Remove irq_timings

[RFD] Remove irq_timings

[Thomas Gleixner]

Daniel!

It's 7 years now that we merged irq timings into the kernel, but we
still have zero users for this.

I'm tempted to declare this experiment failed and remove the whole thing
for good.

Comments?

Thanks,

        tglx

Re: [RFD] Remove irq_timings

[Daniel Lezcano]

Hi Thomas,


On 14/02/2024 22:17, Thomas Gleixner wrote:
> Daniel!
> 
> It's 7 years now that we merged irq timings into the kernel, but we
> still have zero users for this.
> 
> I'm tempted to declare this experiment failed and remove the whole thing
> for good.
> 
> Comments?

I worked on an irq cpuidle governor which had better results than the 
menu governor and equal than the teo governor. But I never succeed to 
have better results without putting some arbitrary when computing the 
next event.

At one moment, Daniel Bristot de Oliveira (Cc'ed) was thinking to may be 
use it for the deadline scheduler.

Ulf (Cc'ed) may be has a plan for the next event for the CPU cluster.

But if no one has plan to use it, there is no good reason to keep it and 
I'm fine if we remove it.



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Re: [RFD] Remove irq_timings

[Ulf Hansson]

On Wed, 14 Feb 2024 at 22:39, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
>
>
> Hi Thomas,
>
>
> On 14/02/2024 22:17, Thomas Gleixner wrote:
> > Daniel!
> >
> > It's 7 years now that we merged irq timings into the kernel, but we
> > still have zero users for this.

Wow, is it really 7 years since then. :-)

> >
> > I'm tempted to declare this experiment failed and remove the whole thing
> > for good.
> >
> > Comments?
>
> I worked on an irq cpuidle governor which had better results than the
> menu governor and equal than the teo governor. But I never succeed to
> have better results without putting some arbitrary when computing the
> next event.
>
> At one moment, Daniel Bristot de Oliveira (Cc'ed) was thinking to may be
> use it for the deadline scheduler.
>
> Ulf (Cc'ed) may be has a plan for the next event for the CPU cluster.

Yes, I still have that plan, but haven't been able to run some real tests yet.

>
> But if no one has plan to use it, there is no good reason to keep it and
> I'm fine if we remove it.

Besides that the code isn't really used at the moment, is it also
blocking us from doing some cleanup/refactoring or other related code?

Kind regards
Uffe

Re: [RFD] Remove irq_timings

[Thomas Gleixner]

On Thu, Feb 15 2024 at 12:23, Ulf Hansson wrote:
> On Wed, 14 Feb 2024 at 22:39, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
>> On 14/02/2024 22:17, Thomas Gleixner wrote:
>> > Daniel!
>> >
>> > It's 7 years now that we merged irq timings into the kernel, but we
>> > still have zero users for this.
>
> Wow, is it really 7 years since then. :-)
>
>> >
>> > I'm tempted to declare this experiment failed and remove the whole thing
>> > for good.
>> >
>> > Comments?
>>
>> I worked on an irq cpuidle governor which had better results than the
>> menu governor and equal than the teo governor. But I never succeed to
>> have better results without putting some arbitrary when computing the
>> next event.
>>
>> At one moment, Daniel Bristot de Oliveira (Cc'ed) was thinking to may be
>> use it for the deadline scheduler.
>>
>> Ulf (Cc'ed) may be has a plan for the next event for the CPU cluster.
>
> Yes, I still have that plan, but haven't been able to run some real tests yet.
>
>>
>> But if no one has plan to use it, there is no good reason to keep it and
>> I'm fine if we remove it.
>
> Besides that the code isn't really used at the moment, is it also
> blocking us from doing some cleanup/refactoring or other related code?

No. I just stumbled over it (again) and wondered whether it is ever
going to be used or not. If not there is no point to carry dead weight
around, but there is no hurry.

Thanks,

        tglx

Re: [RFD] Remove irq_timings

[Ulf Hansson]

On Thu, 15 Feb 2024 at 15:46, Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Thu, Feb 15 2024 at 12:23, Ulf Hansson wrote:
> > On Wed, 14 Feb 2024 at 22:39, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
> >> On 14/02/2024 22:17, Thomas Gleixner wrote:
> >> > Daniel!
> >> >
> >> > It's 7 years now that we merged irq timings into the kernel, but we
> >> > still have zero users for this.
> >
> > Wow, is it really 7 years since then. :-)
> >
> >> >
> >> > I'm tempted to declare this experiment failed and remove the whole thing
> >> > for good.
> >> >
> >> > Comments?
> >>
> >> I worked on an irq cpuidle governor which had better results than the
> >> menu governor and equal than the teo governor. But I never succeed to
> >> have better results without putting some arbitrary when computing the
> >> next event.
> >>
> >> At one moment, Daniel Bristot de Oliveira (Cc'ed) was thinking to may be
> >> use it for the deadline scheduler.
> >>
> >> Ulf (Cc'ed) may be has a plan for the next event for the CPU cluster.
> >
> > Yes, I still have that plan, but haven't been able to run some real tests yet.
> >
> >>
> >> But if no one has plan to use it, there is no good reason to keep it and
> >> I'm fine if we remove it.
> >
> > Besides that the code isn't really used at the moment, is it also
> > blocking us from doing some cleanup/refactoring or other related code?
>
> No. I just stumbled over it (again) and wondered whether it is ever
> going to be used or not. If not there is no point to carry dead weight
> around, but there is no hurry.

Maybe a small chat about it at the next LPC? Then we can see if I have
been able to play more with it.

Kind regards
Uffe

Re: [RFD] Remove irq_timings

[Thomas Gleixner]

On Thu, Mar 07 2024 at 12:54, Ulf Hansson wrote:
> On Thu, 15 Feb 2024 at 15:46, Thomas Gleixner <tglx@linutronix.de> wrote:
>> No. I just stumbled over it (again) and wondered whether it is ever
>> going to be used or not. If not there is no point to carry dead weight
>> around, but there is no hurry.
>
> Maybe a small chat about it at the next LPC? Then we can see if I have
> been able to play more with it.

Works for me.

Thanks,

      tglx