[PATCH 2/3] stop_machine: kill cpu_stop_threads->setup() and cpu_stop_unpark()

[Oleg Nesterov <oleg@redhat.com>]

Now that we always use stop_machine_unpark() to wake the stopper
threas up, we can kill ->setup() and fold cpu_stop_unpark() into
stop_machine_unpark().

And we do not need stopper->lock to set stopper->enabled = true.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/stop_machine.c |   12 +-----------
 1 files changed, 1 insertions(+), 11 deletions(-)

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 59096a5..e5a09d2 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -504,20 +504,11 @@ static void cpu_stop_park(unsigned int cpu)
 	WARN_ON(!list_empty(&stopper->works));
 }
 
-static void cpu_stop_unpark(unsigned int cpu)
-{
-	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
-
-	spin_lock_irq(&stopper->lock);
-	stopper->enabled = true;
-	spin_unlock_irq(&stopper->lock);
-}
-
 void stop_machine_unpark(int cpu)
 {
 	struct cpu_stopper *stopper = &per_cpu(cpu_stopper, cpu);
 
-	cpu_stop_unpark(cpu);
+	stopper->enabled = true;
 	kthread_unpark(stopper->thread);
 }
 
@@ -527,7 +518,6 @@ static struct smp_hotplug_thread cpu_stop_threads = {
 	.thread_fn		= cpu_stopper_thread,
 	.thread_comm		= "migration/%u",
 	.create			= cpu_stop_create,
-	.setup			= cpu_stop_unpark,
 	.park			= cpu_stop_park,
 	.selfparking		= true,
 };
-- 
1.5.5.1