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Date:   Thu, 5 Mar 2020 09:11:35 +0100
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     josh@joshtriplett.org, rostedt@goodmis.org,
        mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com,
        joel@joelfernandes.org, tglx@linutronix.de, swood@redhat.com,
        williams@redhat.com, juri.lelli@redhat.com,
        linux-rt-users@vger.kernel.org, rcu@vger.kernel.org,
        linux-kernel@vger.kernel.org, mingo@kernel.org
Subject: Re: RCU use of swait
Message-ID: <20200305081135.yg7wryd3hrqzocrm@linutronix.de>
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On 2020-03-04 16:35:26 [-0800], Paul E. McKenney wrote:
> Hello!
Hi Paul,

> Or is there some other reason why {S,}RCU needs to use swait that I
> am forgetting?

swait can be used in hardirq-context (on RT) that is in a section within
local_irq_save() / raw_spin_lock() and so.
wait on the hand uses spinlock_t which can not be used in this context.
So if you have no users which fall into that category then you could
move back to wait.h.

> 							Thanx, Paul
Sebastian