sched/core: Get rid of 'cpu' argument in wq_worker_sleeping()

Alexander Gordeev · htejun · commit 9b7f6597f013 · 2016-03-02T10:28:47.000-05:00
Given that wq_worker_sleeping() could only be called for a
CPU it is running on, we do not need passing a CPU ID as an
argument.

Suggested-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Alexander Gordeev &lt;agordeev@redhat.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
@@ -3257,7 +3257,7 @@ static void __sched notrace __schedule(bool preempt)
 			if (prev->flags & PF_WQ_WORKER) {
 				struct task_struct *to_wakeup;
 
-				to_wakeup = wq_worker_sleeping(prev, cpu);
+				to_wakeup = wq_worker_sleeping(prev);
 				if (to_wakeup)
 					try_to_wake_up_local(to_wakeup);
 			}
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
@@ -858,7 +858,6 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
 /**
  * wq_worker_sleeping - a worker is going to sleep
  * @task: task going to sleep
- * @cpu: CPU in question, must be the current CPU number
  *
  * This function is called during schedule() when a busy worker is
  * going to sleep.  Worker on the same cpu can be woken up by
@@ -870,7 +869,7 @@ void wq_worker_waking_up(struct task_struct *task, int cpu)
  * Return:
  * Worker task on @cpu to wake up, %NULL if none.
  */
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
+struct task_struct *wq_worker_sleeping(struct task_struct *task)
 {
 	struct worker *worker = kthread_data(task), *to_wakeup = NULL;
 	struct worker_pool *pool;
@@ -886,7 +885,7 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
 	pool = worker->pool;
 
 	/* this can only happen on the local cpu */
-	if (WARN_ON_ONCE(cpu != raw_smp_processor_id() || pool->cpu != cpu))
+	if (WARN_ON_ONCE(pool->cpu != raw_smp_processor_id()))
 		return NULL;
 
 	/*
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
@@ -69,6 +69,6 @@ static inline struct worker *current_wq_worker(void)
  * sched/core.c and workqueue.c.
  */
 void wq_worker_waking_up(struct task_struct *task, int cpu);
-struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu);
+struct task_struct *wq_worker_sleeping(struct task_struct *task);
 
 #endif /* _KERNEL_WORKQUEUE_INTERNAL_H */

Original file line number	Diff line number	Diff line change
`@@ -3257,7 +3257,7 @@ static void __sched notrace __schedule(bool preempt)`
`3257`	`3257`	`if (prev->flags & PF_WQ_WORKER) {`
`3258`	`3258`	`struct task_struct *to_wakeup;`
`3259`	`3259`
`3260`		`- to_wakeup = wq_worker_sleeping(prev, cpu);`
	`3260`	`+ to_wakeup = wq_worker_sleeping(prev);`
`3261`	`3261`	`if (to_wakeup)`
`3262`	`3262`	`try_to_wake_up_local(to_wakeup);`
`3263`	`3263`	`}`