workqueue: remove @wakeup from worker_set_flags()

worker_set_flags() has only two callers, each specifying %true and
%false for @wakeup.  Let's push the wake up to the caller and remove
@wakeup from worker_set_flags().  The caller can use the following
instead if wakeup is necessary:

	worker_set_flags();
	if (need_more_worker(pool))
 		wake_up_worker(pool);

This makes the code simpler.  This patch doesn't introduce behavior
changes.

tj: Updated description and comments.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

kernel/workqueue.c

@@ -867,35 +867,22 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task, int cpu)
  * worker_set_flags - set worker flags and adjust nr_running accordingly
  * @worker: self
  * @flags: flags to set
- * @wakeup: wakeup an idle worker if necessary
  *
- * Set @flags in @worker->flags and adjust nr_running accordingly.  If
- * nr_running becomes zero and @wakeup is %true, an idle worker is
- * woken up.
+ * Set @flags in @worker->flags and adjust nr_running accordingly.
  *
  * CONTEXT:
  * spin_lock_irq(pool->lock)
  */
-static inline void worker_set_flags(struct worker *worker, unsigned int flags,
-				    bool wakeup)
+static inline void worker_set_flags(struct worker *worker, unsigned int flags)
 {
 	struct worker_pool *pool = worker->pool;
 
 	WARN_ON_ONCE(worker->task != current);
 
-	/*
-	 * If transitioning into NOT_RUNNING, adjust nr_running and
-	 * wake up an idle worker as necessary if requested by
-	 * @wakeup.
-	 */
+	/* If transitioning into NOT_RUNNING, adjust nr_running. */
 	if ((flags & WORKER_NOT_RUNNING) &&
 	    !(worker->flags & WORKER_NOT_RUNNING)) {
-		if (wakeup) {
-			if (atomic_dec_and_test(&pool->nr_running) &&
-			    !list_empty(&pool->worklist))
-				wake_up_worker(pool);
-		} else
-			atomic_dec(&pool->nr_running);
+		atomic_dec(&pool->nr_running);
 	}
 
 	worker->flags |= flags;
@@ -2041,18 +2028,20 @@ __acquires(&pool->lock)
 	list_del_init(&work->entry);
 
 	/*
-	 * CPU intensive works don't participate in concurrency
-	 * management.  They're the scheduler's responsibility.
+	 * CPU intensive works don't participate in concurrency management.
+	 * They're the scheduler's responsibility.  This takes @worker out
+	 * of concurrency management and the next code block will chain
+	 * execution of the pending work items.
 	 */
 	if (unlikely(cpu_intensive))
-		worker_set_flags(worker, WORKER_CPU_INTENSIVE, true);
+		worker_set_flags(worker, WORKER_CPU_INTENSIVE);
 
 	/*
 	 * Wake up another worker if necessary.  The condition is always
 	 * false for normal per-cpu workers since nr_running would always
 	 * be >= 1 at this point.  This is used to chain execution of the
 	 * pending work items for WORKER_NOT_RUNNING workers such as the
-	 * UNBOUND ones.
+	 * UNBOUND and CPU_INTENSIVE ones.
 	 */
 	if (need_more_worker(pool))
 		wake_up_worker(pool);
@@ -2210,7 +2199,7 @@ static int worker_thread(void *__worker)
 		}
 	} while (keep_working(pool));
 
-	worker_set_flags(worker, WORKER_PREP, false);
+	worker_set_flags(worker, WORKER_PREP);
 sleep:
 	/*
 	 * pool->lock is held and there's no work to process and no need to