Re: [PATCH v2 0/5] remove runnable_load_avg and improve group_classify

From: Dietmar Eggemann
Date: Fri Feb 21 2020 - 04:58:21 EST


On 14/02/2020 16:27, Vincent Guittot wrote:
> This new version stays quite close to the previous one and should
> replace without problems the previous one that part of Mel's patchset:
> https://lkml.org/lkml/2020/2/14/156
>
> NUMA load balancing is the last remaining piece of code that uses the
> runnable_load_avg of PELT to balance tasks between nodes. The normal
> load_balance has replaced it by a better description of the current state
> of the group of cpus. The same policy can be applied to the numa
> balancing.
>
> Once unused, runnable_load_avg can be replaced by a simpler runnable_avg
> signal that tracks the waiting time of tasks on rq. Currently, the state
> of a group of CPUs is defined thanks to the number of running task and the
> level of utilization of rq. But the utilization can be temporarly low
> after the migration of a task whereas the rq is still overloaded with
> tasks. In such case where tasks were competing for the rq, the
> runnable_avg will stay high after the migration.

With those small things I commented on:

Reviewed-by: "Dietmar Eggemann <dietmar.eggemann@xxxxxxx>"