Index: thread/thr_mutex.c
===================================================================
RCS file: /home/ncvs/src/lib/libthr/thread/thr_mutex.c,v
retrieving revision 1.54
diff -u -p -r1.54 thr_mutex.c
--- thread/thr_mutex.c	9 May 2007 08:39:33 -0000	1.54
+++ thread/thr_mutex.c	10 Oct 2007 08:56:25 -0000
@@ -356,7 +356,14 @@ mutex_lock_common(struct pthread *curthr
 		ret = mutex_self_lock(m, abstime);
 	} else {
 		if (abstime == NULL) {
-			ret = __thr_umutex_lock(&m->m_lock);
+			int count = 100;
+			while (count--) {
+				ret = _thr_umutex_trylock2(&m->m_lock, id);
+				if (ret == 0)
+					break;
+			}
+			if (ret)
+				ret = __thr_umutex_lock(&m->m_lock);
 		} else if (__predict_false(
 			   abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
 			   abstime->tv_nsec >= 1000000000)) {