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Date:   Tue, 19 Jun 2018 11:47:14 +0200
From:   Juri Lelli <juri.lelli@redhat.com>
To:     Quentin Perret <quentin.perret@arm.com>
Cc:     Pavan Kondeti <pkondeti@codeaurora.org>, peterz@infradead.org,
        rjw@rjwysocki.net, gregkh@linuxfoundation.org,
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        edubezval@gmail.com, srinivas.pandruvada@linux.intel.com,
        currojerez@riseup.net, javi.merino@kernel.org
Subject: Re: [RFC PATCH v3 10/10] arch_topology: Start Energy Aware Scheduling
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On 19/06/18 10:40, Quentin Perret wrote:
> Hi Pavan,
> 
> On Tuesday 19 Jun 2018 at 14:48:41 (+0530), Pavan Kondeti wrote:

[...]

> > There seems to be a sysfs interface exposed by this driver to change cpu_scale.
> > Should we worry about it? I don't know what is the usecase for changing the
> > cpu_scale from user space.
> 
> This is something I've been wondering as well. TBH, I'm not sure what to
> do in this case. And I'm not sure to know what is the use-case either.
> Debugging purpose I assume ?
> 
> Juri, did you have a specific use-case for this feature when the
> arch_topology driver was first introduced ? Or was it just to align
> with the existing arm/arm64 code ?

It was requested (IIRC) because DT might have bogus values and not be
easily modifiable. So, this is another way to get things right for your
platform at runtime.