Re: [PATCH 5/6] cpufreq: Support for fast frequency switching

[Rafael J. Wysocki]

On Thu, Mar 3, 2016 at 12:16 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Wed, Mar 02, 2016 at 03:12:33AM +0100, Rafael J. Wysocki wrote:
>> The most important change from the previous version is that the
>> ->fast_switch() callback takes an additional "relation" argument
>> and now the governor can use it to choose a selection method.
>
>> +unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
>> +                                   unsigned int target_freq,
>> +                                   unsigned int relation)
>
> Would it make sense to replace the {target_freq, relation} pair with
> something like the CPPC {min_freq, max_freq} pair?

Yes, it would in general, but since I use __cpufreq_driver_target() in
the "slow driver" case, that would need to be reworked too for
consistency.  So I'd prefer to do that later.

> Then you could use the closest frequency to max provided it is larger
> than min.
>
> This communicates more actual information in the same number of
> parameters and would thereby allow for a more flexible (better)
> frequency selection.

Agreed.