linux-kernel - Re: [PATCH v7 0/4] Add support for AArch64 AMUv1-based average freq

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Message-ID: <Zx6DmCBYQZkLWRhf@arm.com>
Date: Sun, 27 Oct 2024 19:16:56 +0100
From: Beata Michalska <beata.michalska@....com>
To: viresh.kumar@...aro.org, rafael@...nel.org
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-pm@...r.kernel.org, ionela.voinescu@....com,
	catalin.marinas@....com, sudeep.holla@....com, will@...nel.org,
	sumitg@...dia.com, yang@...amperecomputing.com,
	vanshikonda@...amperecomputing.com, lihuisong@...wei.com,
	zhanjie9@...ilicon.com
Subject: Re: [PATCH v7 0/4] Add support for AArch64 AMUv1-based average freq

On Wed, Oct 16, 2024 at 10:51:57PM +0200, Beata Michalska wrote:
> On Wed, Oct 16, 2024 at 11:59:25AM +0100, Catalin Marinas wrote:

Hi Viresh,
Hi Rafael,

> Hi Catalin,
> > Hi Beata,
> > 
> > On Fri, Sep 13, 2024 at 02:29:40PM +0100, Beata Michalska wrote:
> > > This series adds support for obtaining an average CPU frequency based on
> > > a hardware provided feedback. The average frequency is being exposed via
> > > dedicated yet optional cpufreq sysfs attribute - cpuinfo_avg_freq.
> > > The architecture specific bits are being provided for AArch64, caching on
> > > existing implementation for FIE and AMUv1 support: the frequency scale
> > > factor, updated on each sched tick, serving as a base for retrieving
> > > the frequency for a given CPU, representing an average frequency
> > > reported between the ticks.
> > > 
> > > The changes have been rather lightly (due to some limitations) tested on
> > > an FVP model. Note that some small discrepancies have been observed while
> > > testing (on the model) and this is currently being investigated, though it
> > > should not have any significant impact on the overall results.
> > > 
> > > Note that [PATCH 2/4] arm64: amu: Delay allocating cpumask for AMU FIE support
> > > can be merged independently.
> > 
> > What's the plan with the rest of the patches? Are you going to respin?
> > The first patch would need an ack from Rafael or Viresh if we are to
> > merge them via the arm64 tree.
> >
> I am still waiting on any feedback on [PATCH 1/4] - changes to cpufreq, as that
> one drives the changes in arch specific bits. There is also an ongoing discussion
> on how to handle idle cpu cases - so I would say we still need to agree on few
> details.

Would really appreciate your feedback on above mentioned [PATCH 1/4] ->  [1]
as well as the discussion at [2].

Thank you.

---
[1] https://lore.kernel.org/all/20240913132944.1880703-2-beata.michalska@arm.com/
[2] https://lore.kernel.org/all/ZxAl77IYcMO2SfWh@arm.com/
---
> 
> ---
> BR
> Beata
> > Thanks.
> > 
> > -- 
> > Catalin
>