Index: sys/vm/vm_map.c
===================================================================
--- sys/vm/vm_map.c
+++ sys/vm/vm_map.c
@@ -993,7 +993,7 @@
 
 /* vm_map_entry_succ is defined in vm_map.h. */
 
-#define SPLAY_LEFT_STEP(root, y, rlist, test) do {			\
+#define SPLAY_LEFT_STEP(root, y, rlist, found, test) do {		\
 	vm_size_t max_free;						\
 									\
 	/*								\
@@ -1024,9 +1024,10 @@
 	root->left = rlist;						\
 	rlist = root;							\
 	root = y;							\
+	found = root != NULL;						\
 } while (0)
 
-#define SPLAY_RIGHT_STEP(root, y, llist, test) do {			\
+#define SPLAY_RIGHT_STEP(root, y, llist, found, test) do {		\
 	vm_size_t max_free;						\
 									\
 	/*								\
@@ -1057,6 +1058,7 @@
 	root->right = llist;						\
 	llist = root;							\
 	root = y;							\
+	found = root != NULL;						\
 } while (0)
 
 /*
@@ -1069,55 +1071,52 @@
  * the subsequent call to vm_map_splay_merge, rely on the start and end address
  * values in &map->header.
  */
-static vm_map_entry_t
-vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length,
-    vm_map_entry_t *out_llist, vm_map_entry_t *out_rlist)
-{
-	vm_map_entry_t llist, rlist, root, y;
+#define VM_MAP_SPLAY_SPLIT(map, addr, length, root, llist, rlist, found)\
+do {									\
+	vm_map_entry_t y;						\
+									\
+	llist = rlist = &map->header;					\
+	root = map->root;						\
+	found = root != NULL;						\
+	while (found && root->max_free >= length) {			\
+		KASSERT(llist->end <= root->start &&			\
+		    root->end <= rlist->start,				\
+		    ("%s: root not within tree bounds", __func__));	\
+		if (addr < root->start) {				\
+			SPLAY_LEFT_STEP(root, y, rlist, found,		\
+			    y->max_free >= length && addr < y->start);	\
+		} else if (addr >= root->end) {				\
+			SPLAY_RIGHT_STEP(root, y, llist, found,		\
+			    y->max_free >= length && addr >= y->end);	\
+		} else							\
+			break;						\
+	}								\
+} while (0)
 
-	llist = rlist = &map->header;
-	root = map->root;
-	while (root != NULL && root->max_free >= length) {
-		KASSERT(llist->end <= root->start && root->end <= rlist->start,
-		    ("%s: root not within tree bounds", __func__));
-		if (addr < root->start) {
-			SPLAY_LEFT_STEP(root, y, rlist,
-			    y->max_free >= length && addr < y->start);
-		} else if (addr >= root->end) {
-			SPLAY_RIGHT_STEP(root, y, llist,
-			    y->max_free >= length && addr >= y->end);
-		} else
-			break;
-	}
-	*out_llist = llist;
-	*out_rlist = rlist;
-	return (root);
-}
+#define VM_MAP_SPLAY_FINDNEXT(root, rlist) do {			\
+	vm_map_entry_t hi, y;					\
+	bool found;						\
+								\
+	hi = root->right;					\
+	if (hi == NULL)						\
+		break;						\
+	do							\
+		SPLAY_LEFT_STEP(hi, y, rlist, found, true);	\
+	while (found);						\
+} while (0)
 
-static void
-vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *iolist)
-{
-	vm_map_entry_t rlist, y;
+#define VM_MAP_SPLAY_FINDPREV(root, llist) do {			\
+	vm_map_entry_t lo, y;					\
+	bool found;						\
+								\
+	lo = root->left;					\
+	if (lo == NULL)						\
+		break;						\
+	do							\
+		SPLAY_RIGHT_STEP(lo, y, llist, found, true);	\
+	while (found);						\
+} while (0)
 
-	root = root->right;
-	rlist = *iolist;
-	while (root != NULL)
-		SPLAY_LEFT_STEP(root, y, rlist, true);
-	*iolist = rlist;
-}
-
-static void
-vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *iolist)
-{
-	vm_map_entry_t llist, y;
-
-	root = root->left;
-	llist = *iolist;
-	while (root != NULL)
-		SPLAY_RIGHT_STEP(root, y, llist, true);
-	*iolist = llist;
-}
-
 static inline void
 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b)
 {
@@ -1199,9 +1198,10 @@
 vm_map_splay(vm_map_t map, vm_offset_t addr)
 {
 	vm_map_entry_t llist, rlist, root;
+	bool found;
 
-	root = vm_map_splay_split(map, addr, 0, &llist, &rlist);
-	if (root != NULL) {
+	VM_MAP_SPLAY_SPLIT(map, addr, 0, root, llist, rlist, found);
+	if (found) {
 		/* do nothing */
 	} else if (llist != &map->header) {
 		/*
@@ -1237,14 +1237,15 @@
 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry)
 {
 	vm_map_entry_t llist, rlist, root;
+	bool found;
 
 	CTR3(KTR_VM,
 	    "vm_map_entry_link: map %p, nentries %d, entry %p", map,
 	    map->nentries, entry);
 	VM_MAP_ASSERT_LOCKED(map);
 	map->nentries++;
-	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
-	KASSERT(root == NULL,
+	VM_MAP_SPLAY_SPLIT(map, entry->start, 0, root, llist, rlist, found);
+	KASSERT(!found,
 	    ("vm_map_entry_link: link object already mapped"));
 	entry->prev = llist;
 	entry->next = rlist;
@@ -1264,36 +1265,28 @@
     enum unlink_merge_type op)
 {
 	vm_map_entry_t llist, rlist, root, y;
+	bool found;
 
 	VM_MAP_ASSERT_LOCKED(map);
-	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
-	KASSERT(root != NULL,
-	    ("vm_map_entry_unlink: unlink object not mapped"));
+	VM_MAP_SPLAY_SPLIT(map, entry->start, 0, root, llist, rlist, found);
+	KASSERT(found, ("vm_map_entry_unlink: unlink object not mapped"));
 
-	vm_map_splay_findnext(root, &rlist);
-	switch (op) {
-	case UNLINK_MERGE_NEXT:
+	VM_MAP_SPLAY_FINDPREV(root, llist);
+	VM_MAP_SPLAY_FINDNEXT(root, rlist);
+	if (op == UNLINK_MERGE_NEXT) {
 		rlist->start = root->start;
 		rlist->offset = root->offset;
-		y = root->left;
+	}
+	if (llist != &map->header) {
+		root = llist;
+		llist = root->right;
+		root->right = NULL;
+	} else if (rlist != &map->header) {
 		root = rlist;
 		rlist = root->left;
-		root->left = y;
-		break;
-	case UNLINK_MERGE_NONE:
-		vm_map_splay_findprev(root, &llist);
-		if (llist != &map->header) {
-			root = llist;
-			llist = root->right;
-			root->right = NULL;
-		} else if (rlist != &map->header) {
-			root = rlist;
-			rlist = root->left;
-			root->left = NULL;
-		} else
-			root = NULL;
-		break;
-	}
+		root->left = NULL;
+	} else
+		root = NULL;
 	y = entry->next;
 	y->prev = entry->prev;
 	y->prev->next = y;
@@ -1319,12 +1312,12 @@
 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount)
 {
 	vm_map_entry_t llist, rlist, root;
+	bool found;
 
 	VM_MAP_ASSERT_LOCKED(map);
-	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
-	KASSERT(root != NULL,
-	    ("%s: resize object not mapped", __func__));
-	vm_map_splay_findnext(root, &rlist);
+	VM_MAP_SPLAY_SPLIT(map, entry->start, 0, root, llist, rlist, found);
+	KASSERT(found, ("%s: resize object not mapped", __func__));
+	VM_MAP_SPLAY_FINDNEXT(root, rlist);
 	root->right = NULL;
 	entry->end += grow_amount;
 	vm_map_splay_merge(map, root, llist, rlist);
@@ -1647,7 +1640,7 @@
 {
 	vm_map_entry_t llist, rlist, root, y;
 	vm_size_t left_length;
-	vm_offset_t gap_end;
+	bool found;
 
 	/*
 	 * Request must fit within min/max VM address and must avoid
@@ -1664,16 +1657,14 @@
 	/*
 	 * After splay_split, if start is within an entry, push it to the start
 	 * of the following gap.  If rlist is at the end of the gap containing
-	 * start, save the end of that gap in gap_end to see if the gap is big
-	 * enough; otherwise set gap_end to start skip gap-checking and move
-	 * directly to a search of the right subtree.
+	 * start, clear 'found' and see if the gap is big enough.
 	 */
-	root = vm_map_splay_split(map, start, length, &llist, &rlist);
-	gap_end = rlist->start;
-	if (root != NULL) {
-		start = root->end;
-		if (root->right != NULL)
-			gap_end = start;
+	VM_MAP_SPLAY_SPLIT(map, start, length, root, llist, rlist, found);
+	if (found) {
+		if (root->right == NULL) {
+			start = root->end;
+			found = false;
+		}
 	} else if (rlist != &map->header) {
 		root = rlist;
 		rlist = root->left;
@@ -1685,7 +1676,7 @@
 	}
 	vm_map_splay_merge(map, root, llist, rlist);
 	VM_MAP_ASSERT_CONSISTENT(map);
-	if (length <= gap_end - start)
+	if (!found && length <= rlist->start - start)
 		return (start);
 
 	/* With max_free, can immediately tell if no solution. */
@@ -1699,12 +1690,12 @@
 	for (left_length = 0;;
 	    left_length = vm_map_entry_max_free_left(root, llist)) {
 		if (length <= left_length)
-			SPLAY_LEFT_STEP(root, y, rlist,
+			SPLAY_LEFT_STEP(root, y, rlist, found,
 			    length <= vm_map_entry_max_free_left(y, llist));
 		else
-			SPLAY_RIGHT_STEP(root, y, llist,
+			SPLAY_RIGHT_STEP(root, y, llist, found,
 			    length > vm_map_entry_max_free_left(y, root));
-		if (root == NULL)
+		if (!found)
 			break;
 	}
 	root = llist;