Re: [PATCH 2/4] sched/fair: Small cleanup to sched_balance_newidle()

Peter Zijlstra
2025-11-14T11:05:24Z

On Fri, Nov 14, 2025 at 11:22:48AM +0100, Vincent Guittot wrote:

> sched_balance_update_blocked_averages() can be costly so we want to
> include it in the sd->max_idle_balance_cost so we skip newidle lb and
> update blocked load if avg_idle is shorter than doin the update and
> the newidle lb of the 1st level

Ah, fair enough.

> when sd is null we should still skip
> sched_balance_update_blocked_averages() is its cost is higher than
> avg_idle but it seems that we don't.

When !sd there is no balancing to be had.

Anyway, I'll keep the patch as is -- introducing an early exit for !sd
and I'll post a few more cleanups after this.