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From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Thu, 7 Mar 2024 12:54:02 +0100
Message-ID: <CAPDyKFpnh8nUNXtWUueisExtfabawhsjtEGTnH7RxKeD7=03dQ@mail.gmail.com>
Subject: Re: [RFD] Remove irq_timings
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>, LKML <linux-kernel@vger.kernel.org>, 
	Daniel Bristot de Oliveira <bristot@redhat.com>
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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