Re: [patch v4 11/18] sched: log the cpu utilization at rq

From: Alex Shi
Date: Wed Feb 13 2013 - 22:10:38 EST


On 02/12/2013 06:39 PM, Peter Zijlstra wrote:
> On Thu, 2013-01-24 at 11:06 +0800, Alex Shi wrote:
>>
>> The cpu's utilization is to measure how busy is the cpu.
>> util = cpu_rq(cpu)->avg.runnable_avg_sum
>> / cpu_rq(cpu)->avg.runnable_avg_period;
>>
>> Since the util is no more than 1, we use its percentage value in later
>> caculations. And set the the FULL_UTIL as 100%.
>>
>> In later power aware scheduling, we are sensitive for how busy of the
>> cpu, not how much weight of its load. As to power consuming, it is more
>> related with cpu busy time, not the load weight.
>
> I think we can make that argument in general; that is irrespective of
> the actual policy. We simply never had anything better to go with.
>
> So please clarify why you think this only applies to power aware
> scheduling.

Um, the rq->util is a general argument. It can be used on any other
places if needed, not power aware scheduling specific.
>


--
Thanks
Alex
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