Re: [regression] cross core scheduling frequency drop bisected to 0c313cb20732

Rafael J. Wysocki
2016-04-09T12:31:25Z

On Sat, Apr 9, 2016 at 1:07 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> On Fri, Apr 08, 2016 at 10:59:59PM +0200, Rafael J. Wysocki wrote:
>> On Friday, April 08, 2016 08:50:54 AM Mike Galbraith wrote:
>> > On Fri, 2016-04-08 at 08:45 +0200, Peter Zijlstra wrote:
>> >
>> > > Cute, I thought you used governor=performance for your runs?
>> >
>> > I do, and those numbers are with it thus set.
>>
>> Well, this is a trade-off.
>>
>> 4.5 introduced a power regression here so this one goes back to the previous
>> state of things.
>
> Just for my elucidation; how can gov=performance have a 'power'
> regression?

Because of what is used as the "default" idle state most of the time.

C1 was used before 4.5 and that changed to polling in 4.5.