Re: [RFC 3/4] ARM: topology: Update cpu_power according to DT information

Vincent Guittot
2012-06-13T13:29:35Z

On 13 June 2012 14:47, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2012-06-13 at 18:14 +0530, Amit Kucheria wrote:
>> Various discussions around power-aware scheduling have amplified the
>> need for the scheduler to have some knowledge of DVFS. This would then
>> require the scheduler to track 'cpu_power' ( = max power) and perhaps
>> a new variable 'current_power' that is changed by the DVFS framework.
>
> Note that capacity is in fact a better term -- not to be confused with
> the capacity as currently in use within the load-balancer. Luckily
> there's no way to read that an not be confused.. uhmm :-)
>>
>> The first goal, though, is to make sure that the scheduler can handle
>> different cpu_power values due to asymmetric cores.
>
> I would think the very first goal was to do a simple packing balancer
> before doing silly things with asymmetric setups.. but what do I know.

In fact, there is 2 tracks, one for a power aware scheduler and one
for setting the capacity of each core of a big.LITTLE system. This
patch is for the latter and is not directly link to the power because
the default/performance mode of the scheduler should also take
advantage of this information