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Date: Wed, 24 May 2017 12:57:14 +0200
From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Sebastian Siewior <bigeasy@linutronix.de>,
        Paul McKenney <paulmck@linux.vnet.ibm.com>, linux-s390@vger.kernel.org,
        David Hildenbrand <dahi@linux.vnet.ibm.com>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [patch V3 15/32] s390/kernel: Use stop_machine_cpuslocked()
References: <20170524081511.203800767@linutronix.de>
 <20170524081548.250203087@linutronix.de>
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On Wed, May 24, 2017 at 10:15:26AM +0200, Thomas Gleixner wrote:
> From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> 
> stp_work_fn() holds get_online_cpus() while invoking stop_machine().
> 
> stop_machine() invokes get_online_cpus() as well. This is correct, but
> prevents the conversion of the hotplug locking to a percpu rwsem.
> 
> Use stop_machine_cpuslocked() to avoid the nested call. Convert
> *_online_cpus() to the new interfaces while at it.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-s390@vger.kernel.org
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> ---
>  arch/s390/kernel/time.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>