1 files changed, 46 insertions, 72 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index e1c0e996b5ae..ef071ca73fc3 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4369,8 +4369,8 @@ static void show_pwq(struct pool_workqueue *pwq)
 /**
  * show_workqueue_state - dump workqueue state
  *
- * Called from a sysrq handler and prints out all busy workqueues and
- * pools.
+ * Called from a sysrq handler or try_to_freeze_tasks() and prints out
+ * all busy workqueues and pools.
  */
 void show_workqueue_state(void)
 {
@@ -4600,95 +4600,72 @@ static void restore_unbound_workers_cpumask(struct worker_pool *pool, int cpu)
 	if (!cpumask_test_cpu(cpu, pool->attrs->cpumask))
 		return;
 
-	/* is @cpu the only online CPU? */
 	cpumask_and(&cpumask, pool->attrs->cpumask, cpu_online_mask);
-	if (cpumask_weight(&cpumask) != 1)
-		return;
 
 	/* as we're called from CPU_ONLINE, the following shouldn't fail */
 	for_each_pool_worker(worker, pool)
-		WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task,
-						  pool->attrs->cpumask) < 0);
+		WARN_ON_ONCE(set_cpus_allowed_ptr(worker->task, &cpumask) < 0);
 }
 
-/*
- * Workqueues should be brought up before normal priority CPU notifiers.
- * This will be registered high priority CPU notifier.
- */
-static int workqueue_cpu_up_callback(struct notifier_block *nfb,
-					       unsigned long action,
-					       void *hcpu)
+int workqueue_prepare_cpu(unsigned int cpu)
+{
+	struct worker_pool *pool;
+
+	for_each_cpu_worker_pool(pool, cpu) {
+		if (pool->nr_workers)
+			continue;
+		if (!create_worker(pool))
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+int workqueue_online_cpu(unsigned int cpu)
 {
-	int cpu = (unsigned long)hcpu;
 	struct worker_pool *pool;
 	struct workqueue_struct *wq;
 	int pi;
 
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_UP_PREPARE:
-		for_each_cpu_worker_pool(pool, cpu) {
-			if (pool->nr_workers)
-				continue;
-			if (!create_worker(pool))
-				return NOTIFY_BAD;
-		}
-		break;
-
-	case CPU_DOWN_FAILED:
-	case CPU_ONLINE:
-		mutex_lock(&wq_pool_mutex);
+	mutex_lock(&wq_pool_mutex);
 
-		for_each_pool(pool, pi) {
-			mutex_lock(&pool->attach_mutex);
+	for_each_pool(pool, pi) {
+		mutex_lock(&pool->attach_mutex);
 
-			if (pool->cpu == cpu)
-				rebind_workers(pool);
-			else if (pool->cpu < 0)
-				restore_unbound_workers_cpumask(pool, cpu);
+		if (pool->cpu == cpu)
+			rebind_workers(pool);
+		else if (pool->cpu < 0)
+			restore_unbound_workers_cpumask(pool, cpu);
 
-			mutex_unlock(&pool->attach_mutex);
-		}
+		mutex_unlock(&pool->attach_mutex);
+	}
 
-		/* update NUMA affinity of unbound workqueues */
-		list_for_each_entry(wq, &workqueues, list)
-			wq_update_unbound_numa(wq, cpu, true);
+	/* update NUMA affinity of unbound workqueues */
+	list_for_each_entry(wq, &workqueues, list)
+		wq_update_unbound_numa(wq, cpu, true);
 
-		mutex_unlock(&wq_pool_mutex);
-		break;
-	}
-	return NOTIFY_OK;
+	mutex_unlock(&wq_pool_mutex);
+	return 0;
 }
 
-/*
- * Workqueues should be brought down after normal priority CPU notifiers.
- * This will be registered as low priority CPU notifier.
- */
-static int workqueue_cpu_down_callback(struct notifier_block *nfb,
-						 unsigned long action,
-						 void *hcpu)
+int workqueue_offline_cpu(unsigned int cpu)
 {
-	int cpu = (unsigned long)hcpu;
 	struct work_struct unbind_work;
 	struct workqueue_struct *wq;
 
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_DOWN_PREPARE:
-		/* unbinding per-cpu workers should happen on the local CPU */
-		INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
-		queue_work_on(cpu, system_highpri_wq, &unbind_work);
-
-		/* update NUMA affinity of unbound workqueues */
-		mutex_lock(&wq_pool_mutex);
-		list_for_each_entry(wq, &workqueues, list)
-			wq_update_unbound_numa(wq, cpu, false);
-		mutex_unlock(&wq_pool_mutex);
-
-		/* wait for per-cpu unbinding to finish */
-		flush_work(&unbind_work);
-		destroy_work_on_stack(&unbind_work);
-		break;
-	}
-	return NOTIFY_OK;
+	/* unbinding per-cpu workers should happen on the local CPU */
+	INIT_WORK_ONSTACK(&unbind_work, wq_unbind_fn);
+	queue_work_on(cpu, system_highpri_wq, &unbind_work);
+
+	/* update NUMA affinity of unbound workqueues */
+	mutex_lock(&wq_pool_mutex);
+	list_for_each_entry(wq, &workqueues, list)
+		wq_update_unbound_numa(wq, cpu, false);
+	mutex_unlock(&wq_pool_mutex);
+
+	/* wait for per-cpu unbinding to finish */
+	flush_work(&unbind_work);
+	destroy_work_on_stack(&unbind_work);
+	return 0;
 }
 
 #ifdef CONFIG_SMP
@@ -5490,9 +5467,6 @@ static int __init init_workqueues(void)
 
 	pwq_cache = KMEM_CACHE(pool_workqueue, SLAB_PANIC);
 
-	cpu_notifier(workqueue_cpu_up_callback, CPU_PRI_WORKQUEUE_UP);
-	hotcpu_notifier(workqueue_cpu_down_callback, CPU_PRI_WORKQUEUE_DOWN);
-
 	wq_numa_init();
 
 	/* initialize CPU pools */