Index: kernel/generic/src/synch/waitq.c
===================================================================
--- kernel/generic/src/synch/waitq.c	(revision d99c1d2ba8c7b2c687d430f2e9fd237046606545)
+++ kernel/generic/src/synch/waitq.c	(revision bdfd3c978d7f3378bdc591ff4fe153a17d5c2ea3)
@@ -54,4 +54,5 @@
 #include <context.h>
 #include <adt/list.h>
+#include <arch/cycle.h>
 
 static void waitq_sleep_timed_out(void *data);
@@ -373,4 +374,5 @@
 		if (!context_save(&THREAD->sleep_interruption_context)) {
 			/* Short emulation of scheduler() return code. */
+			THREAD->last_cycle = get_cycle();
 			spinlock_unlock(&THREAD->lock);
 			return ESYNCH_INTERRUPTED;
@@ -385,4 +387,5 @@
 		if (!context_save(&THREAD->sleep_timeout_context)) {
 			/* Short emulation of scheduler() return code. */
+			THREAD->last_cycle = get_cycle();
 			spinlock_unlock(&THREAD->lock);
 			return ESYNCH_TIMEOUT;