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

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Message-ID: <ZxAnbflwMuIWpKCW@arm.com>
Date: Wed, 16 Oct 2024 22:51:57 +0200
From: Beata Michalska <beata.michalska@....com>
To: Catalin Marinas <catalin.marinas@....com>
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-pm@...r.kernel.org, ionela.voinescu@....com,
	sudeep.holla@....com, will@...nel.org, rafael@...nel.org,
	viresh.kumar@...aro.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 11:59:25AM +0100, Catalin Marinas wrote:
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.

---
BR
Beata
> Thanks.
> 
> -- 
> Catalin