Received-SPF: pass (google.com: domain of linux-kernel+bounces-66780-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Precedence: bulk
MIME-Version: 1.0
References: <875xyqg2yr.ffs@tglx> <79fadb9b-c4c8-4727-b812-7e519556cce1@linaro.org>
In-Reply-To: <79fadb9b-c4c8-4727-b812-7e519556cce1@linaro.org>
From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Thu, 15 Feb 2024 12:23:46 +0100
Message-ID: <CAPDyKFoynM_gN=tzsWnE_xAgmy6R8Hie-_yO5zoJTjwNjR38Hg@mail.gmail.com>
Subject: Re: [RFD] Remove irq_timings
To: Daniel Lezcano <daniel.lezcano@linaro.org>, Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>, 
	Daniel Bristot de Oliveira <bristot@redhat.com>
Content-Type: text/plain; charset="UTF-8"

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