cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>
Wed, 24 May 2017 08:15:28 +0000 (10:15 +0200)
committerThomas Gleixner <tglx@linutronix.de>
Fri, 26 May 2017 08:10:42 +0000 (10:10 +0200)
commit210e21331fc3a396af640cec652be769d146e49f
tree6a93eece8fdbd2c9bf77aeeab2a42e84cb7899ec
parentf9a69931c3959940538884d5962b770c3db75df5
cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu()

takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.

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.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.423292433@linutronix.de
kernel/cpu.c