Merge tag 'acpi-5.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...

[linux-2.6-block.git] / kernel / workqueue.c

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 69bd8083930c982b438d02ab1169925d62f5d95e..ddee541ea97aa63863ebcdbee26c437de6b63e42 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -920,6 +920,16 @@ struct task_struct *wq_worker_sleeping(struct task_struct *task)
  * CONTEXT:
  * spin_lock_irq(rq->lock)
  *
+ * This function is called during schedule() when a kworker is going
+ * to sleep. It's used by psi to identify aggregation workers during
+ * dequeuing, to allow periodic aggregation to shut-off when that
+ * worker is the last task in the system or cgroup to go to sleep.
+ *
+ * As this function doesn't involve any workqueue-related locking, it
+ * only returns stable values when called from inside the scheduler's
+ * queuing and dequeuing paths, when @task, which must be a kworker,
+ * is guaranteed to not be processing any works.
+ *
  * Return:
  * The last work function %current executed as a worker, NULL if it
  * hasn't executed any work yet.
@@ -3435,6 +3445,8 @@ static void wq_init_lockdep(struct workqueue_struct *wq)
        lock_name = kasprintf(GFP_KERNEL, "%s%s", "(wq_completion)", wq->name);
        if (!lock_name)
                lock_name = wq->name;
+
+       wq->lock_name = lock_name;
        lockdep_init_map(&wq->lockdep_map, lock_name, &wq->key, 0);
 }
 
@@ -4254,7 +4266,7 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
        INIT_LIST_HEAD(&wq->list);
 
        if (alloc_and_link_pwqs(wq) < 0)
-               goto err_free_wq;
+               goto err_unreg_lockdep;
 
        if (wq_online && init_rescuer(wq) < 0)
                goto err_destroy;
@@ -4280,6 +4292,9 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
 
        return wq;
 
+err_unreg_lockdep:
+       wq_unregister_lockdep(wq);
+       wq_free_lockdep(wq);
 err_free_wq:
        free_workqueue_attrs(wq->unbound_attrs);
        kfree(wq);