Index: uvm_map.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_map.c,v
diff -u -p -r1.331 uvm_map.c
--- uvm_map.c	20 Oct 2024 11:28:17 -0000	1.331
+++ uvm_map.c	20 Oct 2024 11:54:09 -0000
@@ -286,7 +286,7 @@ vaddr_t uvm_maxkaddr;
 	do {								\
 		if ((_map)->ref_count > 0) {				\
 			if (((_map)->flags & VM_MAP_INTRSAFE) == 0)	\
-				rw_assert_wrlock(&(_map)->lock);	\
+				rw_assert_wrlock(&(_map)->lock.rrwl_lock);	\
 			else						\
 				MUTEX_ASSERT_LOCKED(&(_map)->mtx);	\
 		}							\
@@ -2114,8 +2114,6 @@ uvm_map_pageable_wire(struct vm_map *map
 #ifdef DIAGNOSTIC
 	timestamp_save = map->timestamp;
 #endif
-	vm_map_busy(map);
-	vm_map_unlock(map);
 
 	error = 0;
 	for (iter = first; error == 0 && iter != end;
@@ -2128,9 +2126,6 @@ uvm_map_pageable_wire(struct vm_map *map
 		    iter->protection);
 	}
 
-	vm_map_lock(map);
-	vm_map_unbusy(map);
-
 	if (error) {
 #ifdef DIAGNOSTIC
 		if (timestamp_save != map->timestamp)
@@ -2418,11 +2413,10 @@ uvm_map_setup(struct vm_map *map, pmap_t
 	map->s_start = map->s_end = 0; /* Empty stack area by default. */
 	map->flags = flags;
 	map->timestamp = 0;
-	map->busy = NULL;
 	if (flags & VM_MAP_ISVMSPACE)
-		rw_init_flags(&map->lock, "vmmaplk", RWL_DUPOK);
+		rrw_init_flags(&map->lock, "vmmaplk", RWL_DUPOK);
 	else
-		rw_init(&map->lock, "kmmaplk");
+		rrw_init(&map->lock, "kmmaplk");
 	mtx_init(&map->mtx, IPL_VM);
 	mtx_init(&map->flags_lock, IPL_VM);
 
@@ -4467,8 +4461,6 @@ uvm_map_clean(struct vm_map *map, vaddr_
 		}
 	}
 
-	vm_map_busy(map);
-	vm_map_unlock(map);
 	error = 0;
 	for (entry = first; entry != NULL && entry->start < end;
 	    entry = RBT_NEXT(uvm_map_addr, entry)) {
@@ -4487,7 +4479,7 @@ uvm_map_clean(struct vm_map *map, vaddr_
 			goto flush_object;
 
 		if (imut) {
-			vm_map_unbusy(map);
+			vm_map_unlock(map);
 			return EPERM;
 		}
 
@@ -4585,7 +4577,7 @@ flush_object:
 		}
 	}
 
-	vm_map_unbusy(map);
+	vm_map_unlock(map);
 	return error;
 }
 
@@ -5207,26 +5199,9 @@ vm_map_lock_try_ln(struct vm_map *map, c
 		if (!mtx_enter_try(&map->mtx))
 			return FALSE;
 	} else {
-		struct proc *busy;
-
-		mtx_enter(&map->flags_lock);
-		busy = map->busy;
-		mtx_leave(&map->flags_lock);
-		if (busy != NULL && busy != curproc)
-			return FALSE;
-
-		rv = rw_enter(&map->lock, RW_WRITE|RW_NOSLEEP);
+		rv = rrw_enter(&map->lock, RW_WRITE|RW_NOSLEEP);
 		if (rv != 0)
 			return FALSE;
-
-		/* to be sure, to be sure */
-		mtx_enter(&map->flags_lock);
-		busy = map->busy;
-		mtx_leave(&map->flags_lock);
-		if (busy != NULL && busy != curproc) {
-			rw_exit(&map->lock);
-			return FALSE;
-		}
 	}
 
 	map->timestamp++;
@@ -5241,37 +5216,12 @@ void
 vm_map_lock_ln(struct vm_map *map, char *file, int line)
 {
 	if ((map->flags & VM_MAP_INTRSAFE) == 0) {
-		mtx_enter(&map->flags_lock);
-		for (;;) {
-			while (map->busy != NULL && map->busy != curproc) {
-				map->nbusy++;
-				msleep_nsec(&map->busy, &map->mtx,
-				    PVM, vmmapbsy, INFSLP);
-				map->nbusy--;
-			}
-			mtx_leave(&map->flags_lock);
-
-			rw_enter_write(&map->lock);
-
-			/* to be sure, to be sure */
-			mtx_enter(&map->flags_lock);
-			if (map->busy != NULL && map->busy != curproc) {
-				/* go around again */
-				rw_exit_write(&map->lock);
-			} else {
-				/* we won */
-				break;
-			}
-		}
-		mtx_leave(&map->flags_lock);
+		rrw_enter(&map->lock, RW_WRITE);
 	} else {
 		mtx_enter(&map->mtx);
 	}
 
-	if (map->busy != curproc) {
-		KASSERT(map->busy == NULL);
-		map->timestamp++;
-	}
+	map->timestamp++;
 	LPRINTF(("map   lock: %p (at %s %d)\n", map, file, line));
 	uvm_tree_sanity(map, file, line);
 	uvm_tree_size_chk(map, file, line);
@@ -5281,7 +5231,7 @@ void
 vm_map_lock_read_ln(struct vm_map *map, char *file, int line)
 {
 	if ((map->flags & VM_MAP_INTRSAFE) == 0)
-		rw_enter_read(&map->lock);
+		rrw_enter(&map->lock, RW_READ);
 	else
 		mtx_enter(&map->mtx);
 	LPRINTF(("map   lock: %p (at %s %d)\n", map, file, line));
@@ -5292,12 +5242,11 @@ vm_map_lock_read_ln(struct vm_map *map, 
 void
 vm_map_unlock_ln(struct vm_map *map, char *file, int line)
 {
-	KASSERT(map->busy == NULL || map->busy == curproc);
 	uvm_tree_sanity(map, file, line);
 	uvm_tree_size_chk(map, file, line);
 	LPRINTF(("map unlock: %p (at %s %d)\n", map, file, line));
 	if ((map->flags & VM_MAP_INTRSAFE) == 0)
-		rw_exit(&map->lock);
+		rrw_exit(&map->lock);
 	else
 		mtx_leave(&map->mtx);
 }
@@ -5309,46 +5258,17 @@ vm_map_unlock_read_ln(struct vm_map *map
 	/* XXX: RO */ uvm_tree_size_chk(map, file, line);
 	LPRINTF(("map unlock: %p (at %s %d)\n", map, file, line));
 	if ((map->flags & VM_MAP_INTRSAFE) == 0)
-		rw_exit_read(&map->lock);
+		rrw_exit(&map->lock);
 	else
 		mtx_leave(&map->mtx);
 }
 
 void
-vm_map_busy_ln(struct vm_map *map, char *file, int line)
-{
-	KASSERT((map->flags & VM_MAP_INTRSAFE) == 0);
-	KASSERT(rw_write_held(&map->lock));
-	KASSERT(map->busy == NULL);
-
-	mtx_enter(&map->flags_lock);
-	map->busy = curproc;
-	mtx_leave(&map->flags_lock);
-}
-
-void
-vm_map_unbusy_ln(struct vm_map *map, char *file, int line)
-{
-	unsigned int nbusy;
-
-	KASSERT((map->flags & VM_MAP_INTRSAFE) == 0);
-	KASSERT(map->busy == curproc);
-
-	mtx_enter(&map->flags_lock);
-	nbusy = map->nbusy;
-	map->busy = NULL;
-	mtx_leave(&map->flags_lock);
-
-	if (nbusy > 0)
-		wakeup(&map->busy);
-}
-
-void
 vm_map_assert_anylock_ln(struct vm_map *map, char *file, int line)
 {
 	LPRINTF(("map assert read or write locked: %p (at %s %d)\n", map, file, line));
 	if ((map->flags & VM_MAP_INTRSAFE) == 0)
-		rw_assert_anylock(&map->lock);
+		rw_assert_anylock(&map->lock.rrwl_lock);
 	else
 		MUTEX_ASSERT_LOCKED(&map->mtx);
 }
@@ -5359,7 +5279,7 @@ vm_map_assert_wrlock_ln(struct vm_map *m
 	LPRINTF(("map assert write locked: %p (at %s %d)\n", map, file, line));
 	if ((map->flags & VM_MAP_INTRSAFE) == 0) {
 		splassert(IPL_NONE);
-		rw_assert_wrlock(&map->lock);
+		rw_assert_wrlock(&map->lock.rrwl_lock);
 	} else
 		MUTEX_ASSERT_LOCKED(&map->mtx);
 }
Index: uvm_map.h
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_map.h,v
diff -u -p -r1.91 uvm_map.h
--- uvm_map.h	20 Oct 2024 11:28:17 -0000	1.91
+++ uvm_map.h	20 Oct 2024 11:54:09 -0000
@@ -258,8 +258,6 @@ struct vm_map {
 	int			ref_count;	/* [a] Reference count */
 	int			flags;		/* [f] flags */
 	unsigned int		timestamp;	/* Version number */
-	struct proc		*busy;		/* [f] thread holding map busy*/
-	unsigned int		nbusy;		/* [f] waiters for busy */
 
 	vaddr_t			min_offset;	/* [I] First address in map. */
 	vaddr_t			max_offset;	/* [I] Last address in map. */
@@ -305,7 +303,7 @@ struct vm_map {
 	 * XXX struct mutex changes size because of compile options, so
 	 * place after fields which are inspected by libkvm / procmap(8)
 	 */
-	struct rwlock		lock;		/* Non-intrsafe lock */
+	struct rrwlock		lock;		/* Non-intrsafe lock */
 	struct mutex		mtx;		/* Intrsafe lock */
 	struct mutex		flags_lock;	/* flags lock */
 };
@@ -391,10 +389,6 @@ int		uvm_map_fill_vmmap(struct vm_map *,
  *
  *	vm_map_unlock_read: release a shared lock on a map.
  *
- *	vm_map_busy: mark a map as busy.
- *
- *	vm_map_unbusy: clear busy status on a map.
- *
  */
 
 boolean_t	vm_map_lock_try_ln(struct vm_map*, char*, int);
@@ -402,8 +396,6 @@ void		vm_map_lock_ln(struct vm_map*, cha
 void		vm_map_lock_read_ln(struct vm_map*, char*, int);
 void		vm_map_unlock_ln(struct vm_map*, char*, int);
 void		vm_map_unlock_read_ln(struct vm_map*, char*, int);
-void		vm_map_busy_ln(struct vm_map*, char*, int);
-void		vm_map_unbusy_ln(struct vm_map*, char*, int);
 void		vm_map_assert_anylock_ln(struct vm_map*, char*, int);
 void		vm_map_assert_wrlock_ln(struct vm_map*, char*, int);
 
@@ -413,8 +405,6 @@ void		vm_map_assert_wrlock_ln(struct vm_
 #define vm_map_lock_read(map)	vm_map_lock_read_ln(map, __FILE__, __LINE__)
 #define vm_map_unlock(map)	vm_map_unlock_ln(map, __FILE__, __LINE__)
 #define vm_map_unlock_read(map)	vm_map_unlock_read_ln(map, __FILE__, __LINE__)
-#define vm_map_busy(map)	vm_map_busy_ln(map, __FILE__, __LINE__)
-#define vm_map_unbusy(map)	vm_map_unbusy_ln(map, __FILE__, __LINE__)
 #define vm_map_assert_anylock(map)	\
 		vm_map_assert_anylock_ln(map, __FILE__, __LINE__)
 #define vm_map_assert_wrlock(map)	\
@@ -425,8 +415,6 @@ void		vm_map_assert_wrlock_ln(struct vm_
 #define vm_map_lock_read(map)	vm_map_lock_read_ln(map, NULL, 0)
 #define vm_map_unlock(map)	vm_map_unlock_ln(map, NULL, 0)
 #define vm_map_unlock_read(map)	vm_map_unlock_read_ln(map, NULL, 0)
-#define vm_map_busy(map)	vm_map_busy_ln(map, NULL, 0)
-#define vm_map_unbusy(map)	vm_map_unbusy_ln(map, NULL, 0)
 #define vm_map_assert_anylock(map)	vm_map_assert_anylock_ln(map, NULL, 0)
 #define vm_map_assert_wrlock(map)	vm_map_assert_wrlock_ln(map, NULL, 0)
 #endif