[PATCH RT 8/9][RFC] [PATCH 8/9] workqueue: Revert workqueue: Fix PF_THREAD_BOUND abuse

@@ -1286,14 +1286,8 @@ __acquires(&gcwq->lock)
 			return false;
 		if (task_cpu(task) == gcwq->cpu &&
 		    cpumask_equal(&current->cpus_allowed,
-				  get_cpu_mask(gcwq->cpu))) {
-			/*
-			 * Since we're binding to a particular cpu and need to
-			 * stay there for correctness, mark us PF_THREAD_BOUND.
-			 */
-			task->flags |= PF_THREAD_BOUND;
+				  get_cpu_mask(gcwq->cpu)))
 			return true;
-		}
 		spin_unlock_irq(&gcwq->lock);
 
 		/*

@@ -1307,18 +1301,6 @@ __acquires(&gcwq->lock)
 	}
 }
 
-static void worker_unbind_and_unlock(struct worker *worker)
-{
-	struct global_cwq *gcwq = worker->gcwq;
-	struct task_struct *task = worker->task;
-
-	/*
-	 * Its no longer required we're PF_THREAD_BOUND, the work is done.
-	 */
-	task->flags &= ~PF_THREAD_BOUND;
-	spin_unlock_irq(&gcwq->lock);
-}
-
 static struct worker *alloc_worker(void)
 {
 	struct worker *worker;

@@ -1381,9 +1363,15 @@ static struct worker *create_worker(struct global_cwq *gcwq, bool bind)
 	if (IS_ERR(worker->task))
 		goto fail;
 
+	/*
+	 * A rogue worker will become a regular one if CPU comes
+	 * online later on.  Make sure every worker has
+	 * PF_THREAD_BOUND set.
+	 */
 	if (bind && !on_unbound_cpu)
 		kthread_bind(worker->task, gcwq->cpu);
 	else {
+		worker->task->flags |= PF_THREAD_BOUND;
 		if (on_unbound_cpu)
 			worker->flags |= WORKER_UNBOUND;
 	}

@@ -2060,7 +2048,7 @@ repeat:
 		if (keep_working(gcwq))
 			wake_up_worker(gcwq);
 
-		worker_unbind_and_unlock(rescuer);
+		spin_unlock_irq(&gcwq->lock);
 	}
 
 	schedule();

@@ -3009,6 +2997,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *name,
 		if (IS_ERR(rescuer->task))
 			goto err;
 
+		rescuer->task->flags |= PF_THREAD_BOUND;
 		wake_up_process(rescuer->task);
 	}