Re: [PATCH v2 1/5] arch_topology: Introduce thermal pressure update function
From: Dietmar Eggemann
Date: Wed Oct 27 2021 - 09:35:25 EST
On 27/10/2021 10:56, Lukasz Luba wrote:
> Hi Dietmar,
>
> Thank you for having a look at this.
>
> On 10/26/21 5:51 PM, Dietmar Eggemann wrote:
>> On 15/10/2021 16:45, Lukasz Luba wrote:
[...]
>>> +void topology_thermal_pressure_update(const struct cpumask *cpus,
>>> + unsigned long capped_freq)
>>> +{
>>
>> ... why not just s/unsigned long th_pressure/unsigned long capped_freq
>> in existing topology_set_thermal_pressure() and move code the
>> frequency/capacity conversion in there? The patch set will become
>> considerably smaller.
>
> I've been trying to avoid confusion when changing actually behavior
> of the API function. Thus, introducing new would IMO opinion
> make sure the old 'set' function was expecting proper pressure
> value, while the new 'update' expects frequency.
>
> I agree that the patch set would be smaller in that case, but I'm
> not sure if that would not hide some issues. This one would
> definitely break compilation of some vendor modules (or drivers
> queuing or under review), not silently passing them through (with wrong
> argument).
I see, since the parameter type list would stay the same, this could
potentially happen.
[...]