Subject: [RFC PATCH v3 5/6] sched: pack the idle load balance

From: [email-masked] (Arjan van de Ven)
Date: Tue, 23 Apr 2013 08:30:58 -0700

On 4/22/2013 7:23 PM, Alex Shi wrote:
> Thanks you, Preeti and Vincent to talk the power aware scheduler for
> details! believe this open discussion is helpful to conduct a a more
> comprehensive solution. :)
>
>> Hi Preeti,
>>
>> I have had a look at Alex patches but i have some concerns with his patches
>> -There no notion of power domain which is quite important when we speak
>> about power saving IMHO. Packing tasks has got an interest if the idle
>> CPUs can reach a useful low power state independently from busy CPUs.
>> Architectures have different low power state capabilities which must be
>> taken into account. In addition, you can have system which have CPUs
>> with better power efficiency and this kind of system are not taken into
>> account.
>
> I agree with you on this point. and like what's you done to add new flag
> in sched domain.

For x86 we should not be setting such flag then; we don't have a way for some cpu packages to
go to an extra deep power state if they're completely idle.
(this afaik is true for both Intel and AMD)