Re: [PATCH v5 06/12] sched: add per rq cpu_capacity_orig

[Vincent Guittot]

On 10 September 2014 15:53, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Tue, Aug 26, 2014 at 01:06:49PM +0200, Vincent Guittot wrote:
>> This new field cpu_capacity_orig reflects the available capacity of a CPUs
>> unlike the cpu_capacity which reflects the current capacity that can be altered
>> by frequency and rt tasks.
>>
>
> No real objection to the patch as such, but the Changelog fails to tell
> us why you want this.

the cpu_capacity_orig  is used in several places in the following
patches to detect when a CPU's capacity has been noticeably reduced so
we can trig load balance to look for a CPU with full capacity.
As an example, we can detect when a CPU handles a significant amount
of irq (with CONFIG_IRQ_TIME_ACCOUNTING) but is seen as an idle CPU by
scheduler whereas really idle CPU are available
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