--- comparison/sys/kern/kern_thread.c	2010-07-07 22:27:18.000000000 +0200
+++ vm6/sys/kern/kern_thread.c	2010-07-05 03:59:21.000000000 +0200
@@ -164,6 +164,7 @@ thread_init(void *mem, int size, int fla
 
 	td->td_sleepqueue = sleepq_alloc();
 	td->td_turnstile = turnstile_alloc();
+	td->td_rlqe = rlqentry_alloc();
 	EVENTHANDLER_INVOKE(thread_init, td);
 	td->td_sched = (struct td_sched *)&td[1];
 	umtx_thread_init(td);
@@ -181,6 +182,7 @@ thread_fini(void *mem, int size)
 
 	td = (struct thread *)mem;
 	EVENTHANDLER_INVOKE(thread_fini, td);
+	rlqentry_free(td->td_rlqe);
 	turnstile_free(td->td_turnstile);
 	sleepq_free(td->td_sleepqueue);
 	umtx_thread_fini(td);
--- comparison/sys/kern/kern_rangelock.c	2010-07-08 18:29:52.000000000 +0200
+++ vm6/sys/kern/kern_rangelock.c	2010-07-07 00:16:51.000000000 +0200
@@ -33,7 +33,13 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/vnode.h>
 
-uma_zone_t rl_entry_zone;
+struct rl_q_entry {
+	TAILQ_ENTRY(rl_q_entry) rl_q_link;
+	size_t		rl_q_start, rl_q_end;
+	int		rl_q_flags;
+};
+
+static uma_zone_t rl_entry_zone;
 
 static void
 rangelock_sys_init(void)
@@ -41,9 +47,24 @@ rangelock_sys_init(void)
 
 	rl_entry_zone = uma_zcreate("rl_entry", sizeof(struct rl_q_entry),
 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
+	thread0.td_rlqe = rlqentry_alloc();
 }
 SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_ANY, rangelock_sys_init, NULL);
 
+struct rl_q_entry *
+rlqentry_alloc()
+{
+
+	return (uma_zalloc(rl_entry_zone, M_WAITOK));
+}
+
+void
+rlqentry_free(struct rl_q_entry *rleq)
+{
+
+	uma_zfree(rl_entry_zone, rleq);
+}
+
 void
 rangelock_init(struct rangelock *lock)
 {
@@ -113,7 +134,10 @@ rangelock_unlock_vp_locked(struct vnode 
 	TAILQ_REMOVE(&vp->v_rl.rl_waiters, entry, rl_q_link);
 	rangelock_calc_block(&vp->v_rl);
 	VI_UNLOCK(vp);
-	uma_zfree(rl_entry_zone, entry);
+	if (td->td_rlqe == NULL)
+		td->td_rlqe = entry;
+	else
+		rlqentry_free(entry);
 }
 
 void
@@ -166,7 +190,11 @@ rangelock_rlock(struct vnode *vp, off_t 
 {
 	struct rl_q_entry *entry;
 
-	entry = uma_zalloc(rl_entry_zone, M_WAITOK);
+	if (td->td_rlqe != NULL) {
+		entry = td->td_rlqe;
+		td->td_rlqe = NULL;
+	} else
+		entry = rlqentry_alloc();
 	entry->rl_q_flags = RL_LOCK_READ;
 	entry->rl_q_start = base;
 	entry->rl_q_end = base + len;
@@ -178,7 +206,11 @@ rangelock_wlock(struct vnode *vp, off_t 
 {
 	struct rl_q_entry *entry;
 
-	entry = uma_zalloc(rl_entry_zone, M_WAITOK);
+	if (td->td_rlqe != NULL) {
+		entry = td->td_rlqe;
+		td->td_rlqe = NULL;
+	} else
+		entry = rlqentry_alloc();
 	entry->rl_q_flags = RL_LOCK_WRITE;
 	entry->rl_q_start = base;
 	entry->rl_q_end = base + len;
--- comparison/sys/sys/rangelock.h	2010-07-08 18:29:53.000000000 +0200
+++ vm6/sys/sys/rangelock.h	2010-07-07 00:15:19.000000000 +0200
@@ -16,33 +16,30 @@
 
 #ifdef _KERNEL
 
-struct vnode;
-
-struct rl_q_entry
-{
-	TAILQ_ENTRY(rl_q_entry) rl_q_link;
-	size_t rl_q_start, rl_q_end;
-	int rl_q_flags;
-};
-
 #define	RL_LOCK_READ		0x0001
 #define	RL_LOCK_WRITE		0x0002
 #define	RL_LOCK_TYPE_MASK	0x0003
 #define	RL_LOCK_GRANTED		0x0004
 
+struct vnode;
+struct rl_q_entry;
+
 struct rangelock
 {
 	TAILQ_HEAD(, rl_q_entry) rl_waiters;
-	struct rl_q_entry *rl_currdep;
+	struct rl_q_entry	*rl_currdep;
 };
 
-void	rangelock_init(struct rangelock *lock);
-void	rangelock_destroy(struct rangelock *lock);
-void	rangelock_unlock(struct vnode *vp, void *cookie);
-void   *rangelock_unlock_range(struct vnode *vp, void *cookie, off_t base,
-    size_t len);
-void   *rangelock_rlock(struct vnode *vp, off_t base, size_t len);
-void   *rangelock_wlock(struct vnode *vp, off_t base, size_t len);
+void	 rangelock_init(struct rangelock *lock);
+void	 rangelock_destroy(struct rangelock *lock);
+void	 rangelock_unlock(struct vnode *vp, void *cookie);
+void	*rangelock_unlock_range(struct vnode *vp, void *cookie, off_t base,
+	    size_t len);
+void	*rangelock_rlock(struct vnode *vp, off_t base, size_t len);
+void	*rangelock_wlock(struct vnode *vp, off_t base, size_t len);
+
+struct rl_q_entry	*rlqentry_alloc(void);
+void			 rlqentry_free(struct rl_q_entry *rlqe);
 #endif
 
 #endif
--- comparison/sys/sys/proc.h	2010-07-08 18:29:53.000000000 +0200
+++ vm6/sys/sys/proc.h	2010-07-05 03:57:14.000000000 +0200
@@ -209,6 +209,7 @@ struct thread {
 	struct seltd	*td_sel;	/* Select queue/channel. */
 	struct sleepqueue *td_sleepqueue; /* (k) Associated sleep queue. */
 	struct turnstile *td_turnstile;	/* (k) Associated turnstile. */
+	struct rl_q_entry *td_rlqe;	/* (k) Associated range lock entry. */
 	struct umtx_q   *td_umtxq;	/* (c?) Link for when we're blocked. */
 	lwpid_t		td_tid;		/* (b) Thread ID. */
 	sigqueue_t	td_sigqueue;	/* (c) Sigs arrived, not delivered. */