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Sender: Ingo Molnar <mingo.kernel.org@gmail.com>
Date:   Thu, 13 May 2021 14:13:28 +0200
From:   Ingo Molnar <mingo@kernel.org>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     Paul Gortmaker <paul.gortmaker@windriver.com>,
        linux-kernel@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [PATCH] sched/isolation: reconcile rcu_nocbs= and nohz_full=
Message-ID: <YJ0X6MciAc36TMJc@gmail.com>
References: <20210419042659.1134916-1-paul.gortmaker@windriver.com>
 <20210422212448.GJ975577@paulmck-ThinkPad-P17-Gen-1>
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* Paul E. McKenney <paulmck@kernel.org> 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@kernel.org>

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

Thanks,

	Ingo