+ /* Release the scheduler lock while we do the poll.
+ * this means that someone might muck with the blocked_queue
+ * while we do this, but it shouldn't matter:
+ *
+ * - another task might poll for I/O and remove one
+ * or more threads from the blocked_queue.
+ * - more I/O threads may be added to blocked_queue.
+ * - more delayed threads may be added to blocked_queue. We'll
+ * just subtract delta from their delays after the poll.
+ *
+ * I believe none of these cases lead to trouble --SDM.
+ */
+ RELEASE_LOCK(&sched_mutex);
+
+ /* Check for any interesting events */