Re: [RFC 0/2] Optimize the idle CPU search

From: Parth Shah
Date: Mon Jul 08 2019 - 05:09:55 EST




On 7/8/19 1:38 PM, Peter Zijlstra wrote:
> On Mon, Jul 08, 2019 at 10:24:30AM +0530, Parth Shah wrote:
>> When searching for an idle_sibling, scheduler first iterates to search for
>> an idle core and then for an idle CPU. By maintaining the idle CPU mask
>> while iterating through idle cores, we can mark non-idle CPUs for which
>> idle CPU search would not have to iterate through again. This is especially
>> true in a moderately load system
>>
>> Optimize idle CPUs search by marking already found non idle CPUs during
>> idle core search. This reduces iteration count when searching for idle
>> CPUs, resulting in lower iteration count.
>
> Have you seen these patches:
>
> https://lkml.kernel.org/r/20180530142236.667774973@xxxxxxxxxxxxx
>
> I've meant to get back to that, but never quite had the time :/
>

Ok, I was not aware of this patch-set.
It seems interesting and I will evaluate it.


Thanks