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Date:   Mon, 1 Jul 2019 12:24:42 +0200
From:   Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     "Paul E. McKenney" <paulmck@linux.ibm.com>,
        Scott Wood <swood@redhat.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        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
Message-ID: <20190701102442.35grdpcsbrwyyaco@linutronix.de>
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On 2019-07-01 11:42:15 [+0200], Peter Zijlstra wrote:
> I'm not sure if smp_send_reschedule() can be used as self-IPI, some
> hardware doesn't particularly like that IIRC. That is, hardware might
> only have interfaces to IPI _other_ CPUs, but not self.
> 
> The normal scheduler code takes care to not call smp_send_reschedule()
> to self.

and irq_work:
  471ba0e686cb1 ("irq_work: Do not raise an IPI when queueing work on the local CPU")

Sebastian