Re: [PATCH v2 4/4] sched/fair: Rework/fix task_h_load()

From: Kayra Cizmeci

Date: Wed Sep 30 2026 - 01:47:35 EST


Hi Prateek,

> I'm having a super hard time understanding this hierarchy.
I'm new to drawing these sorry. Yes, it's like the second one.

> Yes,d you'll still update h_load for only A and you can have stale
> h_load for C, D, and E, and for all the tasks queued below them.

> Since full propagation is expensive, we do those propagation lazily
> when the task is picked, enqueued, or dequeued

> Note: We cannot propagate this up further because we have not yet done an
> update_load_avg() for the cfa_rq(s) in rest of the hierarchy. Next reweight
> will see the correct h_load starting from A and propagate it further when
> needed.

> Was that the problem you were talking about or did I totally confuse this
> with something else?

Yes, I was talking about that. Because there are only one use case
with tg. I'm not sure the NULL is intentional for that case.

But I can't know for sure Peter can say that. Since..
He wrote the series. :>.

> > I don't think this is that of a problem tho, and
> > I could be missing something.

> I don't even see the problem. Maybe I need glasses :-)

Meh. If you need glasses I need an eye surgery or something.

Thanks,
Kayra