Re: [PATCH] sched/fair: Make sched-idle cpu selection consistent throughout

[Viresh Kumar]

On Wed, 30 Oct 2019 at 22:17, Mel Gorman <mgorman@xxxxxxx> wrote:

> As the patch stands, I think a fork-intensive workload where each
> process is doing small amounts of work will suffer from overloading
> domains and have variable performance depending on how quickly the load
> balancer reacts.

Just wanted to clarify this slightly in case it is confusing. Once a
newly forked
(non SCHED_IDLE) task gets placed on a sched-idle CPU, it won't remain
sched-idle anymore and we will again start looking for a fully idle CPU. So,
we won't put everything on a small set of CPUs, but just one SCHED_NORMAL
task on a CPU unless we are out of idle CPUs.

Do you have some specific test in mind which I can run to test this ?

--
Viresh