Index: src/Makefile.config
===================================================================
--- src/Makefile.config	(revision 425913b9fceb9209b58d45279d34433484ca83e0)
+++ src/Makefile.config	(revision 25f62cdf60b1b680ae1139ed1f9e26ec50ee224f)
@@ -23,6 +23,6 @@
 #TEST_DIR=synch/rwlock2/
 #TEST_DIR=synch/rwlock3/
-#TEST_DIR=synch/rwlock4/
-TEST_DIR=synch/rwlock5/
+TEST_DIR=synch/rwlock4/
+#TEST_DIR=synch/rwlock5/
 #TEST_DIR=synch/semaphore1/
 #TEST_DIR=synch/semaphore2/
Index: src/synch/waitq.c
===================================================================
--- src/synch/waitq.c	(revision 425913b9fceb9209b58d45279d34433484ca83e0)
+++ src/synch/waitq.c	(revision 25f62cdf60b1b680ae1139ed1f9e26ec50ee224f)
@@ -167,4 +167,5 @@
 			 * Short emulation of scheduler() return code.
 			 */
+			before_thread_runs();
 			spinlock_unlock(&THREAD->lock);
 			cpu_priority_restore(pri);