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

From: Vincent Guittot

Date: Fri Nov 14 2025 - 08:11:38 EST


On Fri, 14 Nov 2025 at 12:05, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> 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.

okay