---

yaml
---
r: 350285
b: refs/heads/master
c: 94cf58b
h: refs/heads/master
i:
  350283: f7b121a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d565ed6309300304de4a865a04adef07a85edc45
+refs/heads/master: 94cf58bb2907bd2702fce2266955e29ab5261f53

trunk/kernel/workqueue.c

@@ -1670,10 +1670,10 @@ static void busy_worker_rebind_fn(struct work_struct *work)
 }
 
 /**
- * rebind_workers - rebind all workers of a gcwq to the associated CPU
- * @gcwq: gcwq of interest
+ * rebind_workers - rebind all workers of a pool to the associated CPU
+ * @pool: pool of interest
  *
- * @gcwq->cpu is coming online.  Rebind all workers to the CPU.  Rebinding
+ * @pool->cpu is coming online.  Rebind all workers to the CPU.  Rebinding
  * is different for idle and busy ones.
  *
  * Idle ones will be removed from the idle_list and woken up.  They will
@@ -1691,60 +1691,53 @@ static void busy_worker_rebind_fn(struct work_struct *work)
  * including the manager will not appear on @idle_list until rebind is
  * complete, making local wake-ups safe.
  */
-static void rebind_workers(struct global_cwq *gcwq)
+static void rebind_workers(struct worker_pool *pool)
 {
-	struct worker_pool *pool;
 	struct worker *worker, *n;
 	struct hlist_node *pos;
 	int i;
 
-	for_each_worker_pool(pool, gcwq) {
-		lockdep_assert_held(&pool->assoc_mutex);
-		lockdep_assert_held(&pool->lock);
-	}
+	lockdep_assert_held(&pool->assoc_mutex);
+	lockdep_assert_held(&pool->lock);
 
 	/* dequeue and kick idle ones */
-	for_each_worker_pool(pool, gcwq) {
-		list_for_each_entry_safe(worker, n, &pool->idle_list, entry) {
-			/*
-			 * idle workers should be off @pool->idle_list
-			 * until rebind is complete to avoid receiving
-			 * premature local wake-ups.
-			 */
-			list_del_init(&worker->entry);
+	list_for_each_entry_safe(worker, n, &pool->idle_list, entry) {
+		/*
+		 * idle workers should be off @pool->idle_list until rebind
+		 * is complete to avoid receiving premature local wake-ups.
+		 */
+		list_del_init(&worker->entry);
 
-			/*
-			 * worker_thread() will see the above dequeuing
-			 * and call idle_worker_rebind().
-			 */
-			wake_up_process(worker->task);
-		}
+		/*
+		 * worker_thread() will see the above dequeuing and call
+		 * idle_worker_rebind().
+		 */
+		wake_up_process(worker->task);
+	}
 
-		/* rebind busy workers */
-		for_each_busy_worker(worker, i, pos, pool) {
-			struct work_struct *rebind_work = &worker->rebind_work;
-			struct workqueue_struct *wq;
+	/* rebind busy workers */
+	for_each_busy_worker(worker, i, pos, pool) {
+		struct work_struct *rebind_work = &worker->rebind_work;
+		struct workqueue_struct *wq;
 
-			if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,
-					     work_data_bits(rebind_work)))
-				continue;
+		if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,
+				     work_data_bits(rebind_work)))
+			continue;
 
-			debug_work_activate(rebind_work);
+		debug_work_activate(rebind_work);
 
-			/*
-			 * wq doesn't really matter but let's keep
-			 * @worker->pool and @cwq->pool consistent for
-			 * sanity.
-			 */
-			if (std_worker_pool_pri(worker->pool))
-				wq = system_highpri_wq;
-			else
-				wq = system_wq;
-
-			insert_work(get_cwq(pool->cpu, wq), rebind_work,
-				    worker->scheduled.next,
-				    work_color_to_flags(WORK_NO_COLOR));
-		}
+		/*
+		 * wq doesn't really matter but let's keep @worker->pool
+		 * and @cwq->pool consistent for sanity.
+		 */
+		if (std_worker_pool_pri(worker->pool))
+			wq = system_highpri_wq;
+		else
+			wq = system_wq;
+
+		insert_work(get_cwq(pool->cpu, wq), rebind_work,
+			    worker->scheduled.next,
+			    work_color_to_flags(WORK_NO_COLOR));
 	}
 }
 
@@ -3497,40 +3490,14 @@ EXPORT_SYMBOL_GPL(work_busy);
  * are a lot of assumptions on strong associations among work, cwq and
  * gcwq which make migrating pending and scheduled works very
  * difficult to implement without impacting hot paths.  Secondly,
- * gcwqs serve mix of short, long and very long running works making
+ * worker pools serve mix of short, long and very long running works making
  * blocked draining impractical.
  *
  * This is solved by allowing the pools to be disassociated from the CPU
  * running as an unbound one and allowing it to be reattached later if the
  * cpu comes back online.
  */
 
-/* claim manager positions of all pools */
-static void gcwq_claim_assoc_and_lock(struct global_cwq *gcwq)
-{
-	struct worker_pool *pool;
-
-	for_each_worker_pool(pool, gcwq)
-		mutex_lock_nested(&pool->assoc_mutex, pool - gcwq->pools);
-
-	local_irq_disable();
-	for_each_worker_pool(pool, gcwq)
-		spin_lock_nested(&pool->lock, pool - gcwq->pools);
-}
-
-/* release manager positions */
-static void gcwq_release_assoc_and_unlock(struct global_cwq *gcwq)
-{
-	struct worker_pool *pool;
-
-	for_each_worker_pool(pool, gcwq)
-		spin_unlock(&pool->lock);
-	local_irq_enable();
-
-	for_each_worker_pool(pool, gcwq)
-		mutex_unlock(&pool->assoc_mutex);
-}
-
 static void gcwq_unbind_fn(struct work_struct *work)
 {
 	struct global_cwq *gcwq = get_gcwq(smp_processor_id());
@@ -3539,27 +3506,30 @@ static void gcwq_unbind_fn(struct work_struct *work)
 	struct hlist_node *pos;
 	int i;
 
-	BUG_ON(gcwq->pools[0].cpu != smp_processor_id());
+	for_each_worker_pool(pool, gcwq) {
+		BUG_ON(pool->cpu != smp_processor_id());
 
-	gcwq_claim_assoc_and_lock(gcwq);
+		mutex_lock(&pool->assoc_mutex);
+		spin_lock_irq(&pool->lock);
 
-	/*
-	 * We've claimed all manager positions.  Make all workers unbound
-	 * and set DISASSOCIATED.  Before this, all workers except for the
-	 * ones which are still executing works from before the last CPU
-	 * down must be on the cpu.  After this, they may become diasporas.
-	 */
-	for_each_worker_pool(pool, gcwq) {
+		/*
+		 * We've claimed all manager positions.  Make all workers
+		 * unbound and set DISASSOCIATED.  Before this, all workers
+		 * except for the ones which are still executing works from
+		 * before the last CPU down must be on the cpu.  After
+		 * this, they may become diasporas.
+		 */
 		list_for_each_entry(worker, &pool->idle_list, entry)
 			worker->flags |= WORKER_UNBOUND;
 
 		for_each_busy_worker(worker, i, pos, pool)
 			worker->flags |= WORKER_UNBOUND;
 
 		pool->flags |= POOL_DISASSOCIATED;
-	}
 
-	gcwq_release_assoc_and_unlock(gcwq);
+		spin_unlock_irq(&pool->lock);
+		mutex_unlock(&pool->assoc_mutex);
+	}
 
 	/*
 	 * Call schedule() so that we cross rq->lock and thus can guarantee
@@ -3615,11 +3585,16 @@ static int __cpuinit workqueue_cpu_up_callback(struct notifier_block *nfb,
 
 	case CPU_DOWN_FAILED:
 	case CPU_ONLINE:
-		gcwq_claim_assoc_and_lock(gcwq);
-		for_each_worker_pool(pool, gcwq)
+		for_each_worker_pool(pool, gcwq) {
+			mutex_lock(&pool->assoc_mutex);
+			spin_lock_irq(&pool->lock);
+
 			pool->flags &= ~POOL_DISASSOCIATED;
-		rebind_workers(gcwq);
-		gcwq_release_assoc_and_unlock(gcwq);
+			rebind_workers(pool);
+
+			spin_unlock_irq(&pool->lock);
+			mutex_unlock(&pool->assoc_mutex);
+		}
 		break;
 	}
 	return NOTIFY_OK;