- * Note that it is illegal to call synchronize_srcu_expedited()
- * from the corresponding SRCU read-side critical section; doing so
- * will result in deadlock. However, it is perfectly legal to call
- * synchronize_srcu_expedited() on one srcu_struct from some other
- * srcu_struct's read-side critical section.
+ * Note that it is illegal to call this function while holding any lock
+ * that is acquired by a CPU-hotplug notifier. And yes, it is also illegal
+ * to call this function from a CPU-hotplug notifier. Failing to observe
+ * these restriction will result in deadlock. It is also illegal to call
+ * synchronize_srcu_expedited() from the corresponding SRCU read-side
+ * critical section; doing so will result in deadlock. However, it is
+ * perfectly legal to call synchronize_srcu_expedited() on one srcu_struct
+ * from some other srcu_struct's read-side critical section, as long as
+ * the resulting graph of srcu_structs is acyclic.