Re: [PATCH] sched/isolation: reconcile rcu_nocbs= and nohz_full=

From: Ingo Molnar
Date: Thu May 13 2021 - 08:14:13 EST



* Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:

> On Mon, Apr 19, 2021 at 12:26:59AM -0400, Paul Gortmaker wrote:
> > We have a mismatch between RCU and isolation -- in relation to what is
> > considered the maximum valid CPU number.
> >
> > This matters because nohz_full= and rcu_nocbs= are joined at the hip; in
> > fact the former will enforce the latter. So we don't want a CPU mask to
> > be valid for one and denied for the other.
> >
> > The difference 1st appeared as of v4.15; further details are below.
>
> I pulled this into -rcu for testing and further review.
>
> If it should instead go through some other tree:
>
> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxx>

Thanks - added this fix to tip:sched/core.

Thanks,

Ingo