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Date:   Fri, 28 Jun 2019 15:54:33 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc:     Joel Fernandes <joel@joelfernandes.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
        rcu <rcu@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Josh Triplett <josh@joshtriplett.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Lai Jiangshan <jiangshanlai@gmail.com>
Subject: Re: [RFC] Deadlock via recursive wakeup via RCU with threadirqs
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On Thu, Jun 27, 2019 at 11:41:07AM -0700, Paul E. McKenney wrote:
> Or just don't do the wakeup at all, if it comes to that.  I don't know
> of any way to determine whether rcu_read_unlock() is being called from
> the scheduler, but it has been some time since I asked Peter Zijlstra
> about that.

There (still) is no 'in-scheduler' state.