diff -ru /cvs/sys_old/kern/kern_mutex.c /usr/src/sys/kern/kern_mutex.c
--- /cvs/sys_old/kern/kern_mutex.c	Sat Jan 13 01:58:53 2001
+++ /usr/src/sys/kern/kern_mutex.c	Sat Jan 13 15:06:04 2001
@@ -88,11 +88,11 @@
 #ifdef WITNESS
 static struct mtx_debug all_mtx_debug = { NULL, {NULL, NULL}, NULL, 0,
 	"All mutexes queue head" };
-static struct mtx all_mtx = { MTX_UNOWNED, 0, 0, &all_mtx_debug,
+static struct mtx all_mtx = { MTX_UNOWNED, 0, 0, 0, &all_mtx_debug,
 	TAILQ_HEAD_INITIALIZER(all_mtx.mtx_blocked),
 	{ NULL, NULL }, &all_mtx, &all_mtx };
 #else	/* WITNESS */
-static struct mtx all_mtx = { MTX_UNOWNED, 0, 0, "All mutexes queue head",
+static struct mtx all_mtx = { MTX_UNOWNED, 0, 0, 0, "All mutexes queue head",
 	TAILQ_HEAD_INITIALIZER(all_mtx.mtx_blocked),
 	{ NULL, NULL }, &all_mtx, &all_mtx };
 #endif	/* WITNESS */
@@ -257,7 +257,9 @@
 
 	switch (type) {
 	case MTX_DEF:
-		if ((m->mtx_lock & MTX_FLAGMASK) == (uintptr_t)p) {
+		if (((m->mtx_lock & MTX_FLAGMASK) == (uintptr_t)p)) {
+			KASSERT(m->mtx_type & MTX_RECUR,
+			    ("Attempting to recurse on a non-recursive lock."));
 			m->mtx_recurse++;
 			atomic_set_ptr(&m->mtx_lock, MTX_RECURSE);
 			if ((type & MTX_QUIET) == 0)
@@ -284,7 +286,7 @@
 			uintptr_t v;
 			struct proc *p1;
 
-			mtx_enter(&sched_lock, MTX_SPIN | MTX_RLIKELY);
+			mtx_enter(&sched_lock, MTX_SPIN);
 			/*
 			 * check if the lock has been released while
 			 * waiting for the schedlock.
@@ -385,6 +387,8 @@
 		int i = 0;
 
 		if (m->mtx_lock == (uintptr_t)p) {
+			KASSERT(m->mtx_type & MTX_RECUR,
+			   ("Attempting to recurse on a non-recursive lock."));
 			m->mtx_recurse++;
 			return;
 		}
@@ -434,7 +438,9 @@
 	switch (type) {
 	case MTX_DEF:
 	case MTX_DEF | MTX_NOSWITCH:
-		if (m->mtx_recurse != 0) {
+		if (mtx_recursed(m)) {
+			KASSERT(m->mtx_type & MTX_RECUR,
+			    ("Dropping recurse cnt on a non-recursive lock."));
 			if (--(m->mtx_recurse) == 0)
 				atomic_clear_ptr(&m->mtx_lock, MTX_RECURSE);
 			if ((type & MTX_QUIET) == 0)
@@ -501,7 +507,9 @@
 		break;
 	case MTX_SPIN:
 	case MTX_SPIN | MTX_FIRST:
-		if (m->mtx_recurse != 0) {
+		if (mtx_recursed(m)) {
+			KASSERT(m->mtx_type & MTX_RECUR,
+			    ("Dropping recurse cnt on a non-recursive lock."));
 			m->mtx_recurse--;
 			return;
 		}
@@ -515,7 +523,9 @@
 		}
 		break;
 	case MTX_SPIN | MTX_TOPHALF:
-		if (m->mtx_recurse != 0) {
+		if (mtx_recursed(m)) {
+			KASSERT(m->mtx_type & MTX_RECUR,
+			    ("Dropping recurse cnt on a non-recursive lock."));
 			m->mtx_recurse--;
 			return;
 		}
@@ -630,6 +640,9 @@
 #endif
 	m->mtx_description = t;
 	m->mtx_lock = MTX_UNOWNED;
+
+	m->mtx_type |= (flag & MTX_RECUR);
+
 	/* Put on all mutex queue */
 	mtx_enter(&all_mtx, MTX_DEF);
 	m->mtx_next = &all_mtx;
@@ -841,7 +854,7 @@
 		if (!w->w_spin)
 			panic("mutex_enter: MTX_SPIN on MTX_DEF mutex %s @"
 			    " %s:%d", m->mtx_description, file, line);
-		if (m->mtx_recurse != 0)
+		if (mtx_recursed(m))
 			return;
 		mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET);
 		i = PCPU_GET(witness_spin_check);
@@ -864,7 +877,7 @@
 		panic("mutex_enter: MTX_DEF on MTX_SPIN mutex %s @ %s:%d",
 		    m->mtx_description, file, line);
 
-	if (m->mtx_recurse != 0)
+	if (mtx_recursed(m))
 		return;
 	if (witness_dead)
 		goto out;
@@ -974,7 +987,7 @@
 		if (!w->w_spin)
 			panic("mutex_exit: MTX_SPIN on MTX_DEF mutex %s @"
 			    " %s:%d", m->mtx_description, file, line);
-		if (m->mtx_recurse != 0)
+		if (mtx_recursed(m))
 			return;
 		mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET);
 		PCPU_SET(witness_spin_check,
@@ -986,7 +999,7 @@
 		panic("mutex_exit: MTX_DEF on MTX_SPIN mutex %s @ %s:%d",
 		    m->mtx_description, file, line);
 
-	if (m->mtx_recurse != 0)
+	if (mtx_recursed(m))
 		return;
 
 	if ((flags & MTX_NOSWITCH) == 0 && !mtx_legal2block() && !cold)
@@ -1009,7 +1022,7 @@
 			panic("mutex_try_enter: "
 			    "MTX_SPIN on MTX_DEF mutex %s @ %s:%d",
 			    m->mtx_description, file, line);
-		if (m->mtx_recurse != 0)
+		if (mtx_recursed(m))
 			return;
 		mtx_enter(&w_mtx, MTX_SPIN | MTX_QUIET);
 		PCPU_SET(witness_spin_check,
@@ -1026,7 +1039,7 @@
 		panic("mutex_try_enter: MTX_DEF on MTX_SPIN mutex %s @ %s:%d",
 		    m->mtx_description, file, line);
 
-	if (m->mtx_recurse != 0)
+	if (mtx_recursed(m))
 		return;
 
 	w->w_file = file;
diff -ru /cvs/sys_old/sys/mutex.h /usr/src/sys/sys/mutex.h
--- /cvs/sys_old/sys/mutex.h	Sat Jan 13 01:59:29 2001
+++ /usr/src/sys/sys/mutex.h	Sat Jan 13 03:47:42 2001
@@ -63,12 +63,11 @@
  *
  * Types
  */
-#define	MTX_DEF		0x0		/* Default (spin/sleep) */
-#define MTX_SPIN	0x1		/* Spin only lock */
+#define	MTX_DEF		0x00000000	/* Default (spin/sleep) */
+#define MTX_SPIN	0x00000001	/* Spin only lock */
+#define MTX_RECUR	0x00000002	/* Recursive lock */
 
 /* Options */
-#define	MTX_RLIKELY	0x4		/* (opt) Recursion likely */
-#define	MTX_NORECURSE	0x8		/* No recursion possible */
 #define	MTX_NOSPIN	0x10		/* Don't spin before sleeping */
 #define	MTX_NOSWITCH	0x20		/* Do not switch on release */
 #define	MTX_FIRST	0x40		/* First spin lock holder */
@@ -109,6 +108,7 @@
 struct mtx {
 	volatile uintptr_t mtx_lock;	/* lock owner/gate/flags */
 	volatile u_int	mtx_recurse;	/* number of recursive holds */
+	u_int		mtx_type;	/* lock type */
 	u_int		mtx_saveintr;	/* saved flags (for spin locks) */
 #ifdef WITNESS
 	struct mtx_debug *mtx_debug;
@@ -453,7 +453,7 @@
 char	STR_mtx_enter_fmt[] = "GOT %s [%p] r=%d at %s:%d";
 char	STR_mtx_exit_fmt[] = "REL %s [%p] r=%d at %s:%d";
 char	STR_mtx_try_enter_fmt[] = "TRY_ENTER %s [%p] result=%d at %s:%d";
-char	STR_mtx_bad_type[] = "((type) & (MTX_NORECURSE | MTX_NOSWITCH)) == 0";
+char	STR_mtx_bad_type[] = "((type) & MTX_NOSWITCH) == 0";
 char	STR_mtx_owned[] = "mtx_owned(mpp)";
 char	STR_mtx_recurse[] = "mpp->mtx_recurse == 0";
 #else	/* _KERN_MUTEX_C_ */
@@ -478,19 +478,18 @@
 	struct mtx	*mpp = mtxp;
 
 	/* bits only valid on mtx_exit() */
-	MPASS4(((type) & (MTX_NORECURSE | MTX_NOSWITCH)) == 0,
-	    STR_mtx_bad_type, file, line);
+	MPASS4(((type) & MTX_NOSWITCH) == 0, STR_mtx_bad_type, file, line);
 
 	if ((type) & MTX_SPIN) {
 		/*
 		 * Easy cases of spin locks:
 		 *
 		 * 1) We already own the lock and will simply recurse on it (if
-		 *    RLIKELY)
+		 *    RECUR)
 		 *
 		 * 2) The lock is free, we just get it
 		 */
-		if ((type) & MTX_RLIKELY) {
+		if (mpp->mtx_type & MTX_RECUR) {
 			/*
 			 * Check for recursion, if we already have this
 			 * lock we just bump the recursion count.
@@ -519,7 +518,7 @@
 			_getlock_norecurse(mpp, CURTHD, (type) & MTX_HARDOPTS);
 	} else {
 		/* Sleep locks */
-		if ((type) & MTX_RLIKELY)
+		if (mpp->mtx_type & MTX_RECUR)
 			_getlock_sleep(mpp, CURTHD, (type) & MTX_HARDOPTS);
 		else
 			_getlock_norecurse(mpp, CURTHD, (type) & MTX_HARDOPTS);
@@ -571,7 +570,7 @@
 		CTR5(KTR_LOCK, STR_mtx_exit_fmt,
 		    mpp->mtx_description, mpp, mpp->mtx_recurse, file, line);
 	if ((type) & MTX_SPIN) {
-		if ((type) & MTX_NORECURSE) {
+		if ((mpp->mtx_type & MTX_RECUR) == 0) {
 			int mtx_intr = mpp->mtx_saveintr;
 
 			MPASS4(mpp->mtx_recurse == 0, STR_mtx_recurse,
@@ -594,7 +593,7 @@
 		}
 	} else {
 		/* Handle sleep locks */
-		if ((type) & MTX_RLIKELY)
+		if (mpp->mtx_type & MTX_RECUR)
 			_exitlock(mpp, CURTHD, (type) & MTX_HARDOPTS);
 		else {
 			_exitlock_norecurse(mpp, CURTHD,