schedule_on_each_cpu(): use preempt_disable()

We take workqueue_mutex in there to keep CPU hotplug away.  But
preempt_disable() will suffice for that.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index b6fa5e63085d..1ea4bcb86974 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -638,7 +638,7 @@ int schedule_on_each_cpu(work_func_t func)
         if (!works)
                 return -ENOMEM;
 
-        mutex_lock(&workqueue_mutex);
+        preempt_disable();              /* CPU hotplug */
         for_each_online_cpu(cpu) {
                 struct work_struct *work = per_cpu_ptr(works, cpu);
 
@@ -646,7 +646,7 @@ int schedule_on_each_cpu(work_func_t func)
                 set_bit(WORK_STRUCT_PENDING, work_data_bits(work));
                 __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), work);
         }
-        mutex_unlock(&workqueue_mutex);
+        preempt_enable();
         flush_workqueue(keventd_wq);
         free_percpu(works);
         return 0;