linux-kernel - Re: [PATCH v1 0/2] cpuidle: teo: Refine handling of short idle intervals

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Message-ID: <CAJZ5v0iJpXBp5A-ozrjFeG=m+wj2NJYOwNPy-NAgKNXR2ySYYg@mail.gmail.com>
Date: Wed, 9 Apr 2025 14:06:52 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>, Linux PM <linux-pm@...r.kernel.org>, 
	LKML <linux-kernel@...r.kernel.org>, Daniel Lezcano <daniel.lezcano@...aro.org>, 
	Christian Loehle <christian.loehle@....com>, Doug Smythies <dsmythies@...us.net>, 
	Aboorva Devarajan <aboorvad@...ux.ibm.com>
Subject: Re: [PATCH v1 0/2] cpuidle: teo: Refine handling of short idle intervals

On Wed, Apr 9, 2025 at 8:52 AM Artem Bityutskiy
<artem.bityutskiy@...ux.intel.com> wrote:
>
> On Thu, 2025-04-03 at 21:16 +0200, Rafael J. Wysocki wrote:
> > Hi Everyone,
> >
> > This series is intended to address an issue with overly aggressive selection
> > of idle state 0 (the polling state) in teo on x86 in some cases when timer
> > wakeups dominate the CPU wakeup pattern.
>
> Hi Rafael, I ran SPECjbb2015 with and without these 2 patches on Granite Rapids
> Xeon (GNR).
>
> Expectation: no measurable difference, because there is almost no POLL in case
> of SPECjbb2015 on GNR.
>
> Result: no measurable difference.
>
> Conclusion: these 2 patches do not introduce a regression as measured by
> SPECjbb2015 on GNR.
>
> "No regression" is also a useful piece of information, so reporting.

Thank you!