workqueue: implement current_is_workqueue_rescuer()
Implement a function which queries whether it currently is running off
a workqueue rescuer. This will be used to convert writeback to
workqueue.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index c82feac..f5c8bbb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4072,6 +4072,19 @@
EXPORT_SYMBOL_GPL(workqueue_set_max_active);
/**
+ * current_is_workqueue_rescuer - is %current workqueue rescuer?
+ *
+ * Determine whether %current is a workqueue rescuer. Can be used from
+ * work functions to determine whether it's being run off the rescuer task.
+ */
+bool current_is_workqueue_rescuer(void)
+{
+ struct worker *worker = current_wq_worker();
+
+ return worker && worker == worker->current_pwq->wq->rescuer;
+}
+
+/**
* workqueue_congested - test whether a workqueue is congested
* @cpu: CPU in question
* @wq: target workqueue
