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Index: vm_map.c
===================================================================
--- vm_map.c
+++ vm_map.c
@@ -956,55 +956,68 @@
/*
* vm_map_entry_set_max_free:
*
- * Set the max_free field in a vm_map_entry.
+ * Compute the size of the largest free gap between two entries,
+ * one the root of a tree and the other the ancestor of that root
+ * that is the least or greatest ancestor found on the search path.
*/
-static inline void
-vm_map_entry_set_max_free(vm_map_entry_t entry)
+static inline vm_size_t
+vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor)
{
- vm_map_entry_t child;
- vm_size_t max_left, max_right;
- child = entry->left;
- max_left = (child != NULL) ? child->max_free :
- entry->start - entry->prev->end;
- child = entry->right;
- max_right = (child != NULL) ? child->max_free :
- entry->next->start - entry->end;
- entry->max_free = MAX(max_left, max_right);
+ return (root->left != NULL ?
+ root->left->max_free : root->start - left_ancestor->end);
}
-#define SPLAY_LEFT_STEP(root, y, rlist, test) do { \
- y = root->left; \
- if (y != NULL && (test)) { \
- /* Rotate right and make y root. */ \
- root->left = y->right; \
- y->right = root; \
- vm_map_entry_set_max_free(root); \
- root = y; \
- y = root->left; \
- } \
- /* Put root on rlist. */ \
- root->left = rlist; \
- rlist = root; \
- root = y; \
-} while (0)
+static inline vm_size_t
+vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor)
+{
-#define SPLAY_RIGHT_STEP(root, y, llist, test) do { \
- y = root->right; \
- if (y != NULL && (test)) { \
- /* Rotate left and make y root. */ \
- root->right = y->left; \
- y->left = root; \
- vm_map_entry_set_max_free(root); \
- root = y; \
- y = root->right; \
- } \
- /* Put root on llist. */ \
- root->right = llist; \
- llist = root; \
- root = y; \
+ return (root->right != NULL ?
+ root->right->max_free : right_ancestor->start - root->end);
+}
+
+#define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do { \
+ y = root->left; \
+ if (y != NULL && (test)) { \
+ /* Rotate right and make y root. */ \
+ root->left = y->right; \
+ y->right = root; \
+ if (root->max_free == y->max_free) \
+ root->max_free = MAX( \
+ vm_map_entry_max_free_left(root, y), \
+ vm_map_entry_max_free_right(root, rlist)); \
+ y->max_free = root->max_free; \
+ root = y; \
+ y = root->left; \
+ } else if (root->max_free == vm_map_entry_max_free_left(root, llist)) \
+ root->max_free = vm_map_entry_max_free_right(root, rlist); \
+ /* Put root on rlist. */ \
+ root->left = rlist; \
+ rlist = root; \
+ root = y; \
} while (0)
+#define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do { \
+ y = root->right; \
+ if (y != NULL && (test)) { \
+ /* Rotate left and make y root. */ \
+ root->right = y->left; \
+ y->left = root; \
+ if (root->max_free == y->max_free) \
+ root->max_free = MAX( \
+ vm_map_entry_max_free_left(root, llist), \
+ vm_map_entry_max_free_right(root, y)); \
+ y->max_free = root->max_free; \
+ root = y; \
+ y = root->right; \
+ } else if (root->max_free == vm_map_entry_max_free_right(root, rlist)) \
+ root->max_free = vm_map_entry_max_free_left(root, llist); \
+ /* Put root on llist. */ \
+ root->right = llist; \
+ llist = root; \
+ root = y; \
+ } while (0)
+
/*
* Walk down the tree until we find addr or a NULL pointer where addr would go,
* breaking off left and right subtrees of nodes less than, or greater than
@@ -1015,49 +1028,51 @@
*/
static vm_map_entry_t
vm_map_splay_split(vm_offset_t addr, vm_size_t length,
- vm_map_entry_t root, vm_map_entry_t *out_llist, vm_map_entry_t *out_rlist)
+ vm_map_entry_t root, vm_map_entry_t *io_llist, vm_map_entry_t *io_rlist)
{
vm_map_entry_t llist, rlist;
vm_map_entry_t y;
- llist = NULL;
- rlist = NULL;
+ llist = *io_llist;
+ rlist = *io_rlist;
while (root != NULL && root->max_free >= length) {
if (addr < root->start) {
- SPLAY_LEFT_STEP(root, y, rlist,
+ SPLAY_LEFT_STEP(root, y, llist, rlist,
y->max_free >= length && addr < y->start);
} else if (addr >= root->end) {
- SPLAY_RIGHT_STEP(root, y, llist,
+ SPLAY_RIGHT_STEP(root, y, llist, rlist,
y->max_free >= length && addr >= y->end);
} else
break;
}
- *out_llist = llist;
- *out_rlist = rlist;
+ *io_llist = llist;
+ *io_rlist = rlist;
return (root);
}
static void
vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *iolist)
{
- vm_map_entry_t rlist, y;
+ vm_map_entry_t llist, rlist, y;
+ llist = root;
root = root->right;
rlist = *iolist;
while (root != NULL)
- SPLAY_LEFT_STEP(root, y, rlist, true);
+ SPLAY_LEFT_STEP(root, y, llist, 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;
+ vm_map_entry_t llist, rlist, y;
+ rlist = root;
root = root->left;
llist = *iolist;
while (root != NULL)
- SPLAY_RIGHT_STEP(root, y, llist, true);
+ SPLAY_RIGHT_STEP(root, y, llist, rlist, true);
*iolist = llist;
}
@@ -1065,40 +1080,48 @@
* Walk back up the two spines, flip the pointers and set max_free. The
* subtrees of the root go at the bottom of llist and rlist.
*/
-static vm_map_entry_t
+static void
vm_map_splay_merge(vm_map_entry_t root,
- vm_map_entry_t llist, vm_map_entry_t rlist,
- vm_map_entry_t ltree, vm_map_entry_t rtree)
+ vm_map_entry_t llist, vm_map_entry_t rlist)
{
- vm_map_entry_t y;
+ vm_map_entry_t tree, y;
+ vm_size_t max_free;
- while (llist != NULL) {
+ tree = root->left;
+ if ((llist->eflags & MAP_ENTRY_HEADER) == 0)
+ max_free = vm_map_entry_max_free_left(root, llist);
+ while ((llist->eflags & MAP_ENTRY_HEADER) == 0) {
y = llist->right;
- llist->right = ltree;
- vm_map_entry_set_max_free(llist);
- ltree = llist;
+ llist->right = tree;
+ if (llist->max_free < max_free)
+ llist->max_free = max_free;
+ else
+ max_free = llist->max_free;
+ tree = llist;
llist = y;
}
- while (rlist != NULL) {
+ root->left = tree;
+ tree = root->right;
+ if ((rlist->eflags & MAP_ENTRY_HEADER) == 0)
+ max_free = vm_map_entry_max_free_right(root, rlist);
+ while ((rlist->eflags & MAP_ENTRY_HEADER) == 0) {
y = rlist->left;
- rlist->left = rtree;
- vm_map_entry_set_max_free(rlist);
- rtree = rlist;
+ rlist->left = tree;
+ if (rlist->max_free < max_free)
+ rlist->max_free = max_free;
+ else
+ max_free = rlist->max_free;
+ tree = rlist;
rlist = y;
}
-
- /*
- * Final assembly: add ltree and rtree as subtrees of root.
- */
- root->left = ltree;
- root->right = rtree;
- vm_map_entry_set_max_free(root);
-
- return (root);
+ root->right = tree;
+ root->max_free = MAX(
+ vm_map_entry_max_free_left(root, llist),
+ vm_map_entry_max_free_right(root, rlist));
}
/*
- * vm_map_entry_splay:
+ * vm_map_splay:
*
* The Sleator and Tarjan top-down splay algorithm with the
* following variation. Max_free must be computed bottom-up, so
@@ -1115,14 +1138,16 @@
* Returns: the new root.
*/
static vm_map_entry_t
-vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root)
+vm_map_splay(vm_offset_t addr, vm_map_t map)
{
- vm_map_entry_t llist, rlist;
+ vm_map_entry_t llist, rlist, root;
- root = vm_map_splay_split(addr, 0, root, &llist, &rlist);
+ VM_MAP_ASSERT_CONSISTENT(map);
+ llist = rlist = &map->header;
+ root = vm_map_splay_split(addr, 0, map->root, &llist, &rlist);
if (root != NULL) {
/* do nothing */
- } else if (llist != NULL) {
+ } else if ((llist->eflags & MAP_ENTRY_HEADER) == 0) {
/*
* Recover the greatest node in the left
* subtree and make it the root.
@@ -1130,7 +1155,7 @@
root = llist;
llist = root->right;
root->right = NULL;
- } else if (rlist != NULL) {
+ } else if ((rlist->eflags & MAP_ENTRY_HEADER) == 0) {
/*
* Recover the least node in the right
* subtree and make it the root.
@@ -1142,8 +1167,10 @@
/* There is no root. */
return (NULL);
}
- return (vm_map_splay_merge(root, llist, rlist,
- root->left, root->right));
+ vm_map_splay_merge(root, llist, rlist);
+ map->root = root;
+ VM_MAP_ASSERT_CONSISTENT(map);
+ return (root);
}
/*
@@ -1161,15 +1188,40 @@
"vm_map_entry_link: map %p, nentries %d, entry %p", map,
map->nentries, entry);
VM_MAP_ASSERT_LOCKED(map);
+ VM_MAP_ASSERT_CONSISTENT(map);
map->nentries++;
- root = map->root;
- root = vm_map_splay_split(entry->start, 0, root, &llist, &rlist);
- KASSERT(root == NULL,
- ("vm_map_entry_link: link object already mapped"));
- entry->prev = (llist == NULL) ? &map->header : llist;
- entry->next = (rlist == NULL) ? &map->header : rlist;
- entry->prev->next = entry->next->prev = entry;
- root = vm_map_splay_merge(entry, llist, rlist, NULL, NULL);
+ llist = rlist = &map->header;
+ root = vm_map_splay_split(entry->start, 0, map->root, &llist, &rlist);
+ if (root != NULL &&
+ entry->start == root->start && entry->end < root->end) {
+ if (root->max_free == vm_map_entry_max_free_left(root, llist))
+ root->max_free =
+ vm_map_entry_max_free_right(root, rlist);
+ vm_map_splay_findprev(root, &llist);
+ root->left = rlist;
+ rlist = root;
+ rlist->offset += entry->end - rlist->start;
+ rlist->start = entry->end;
+ } else if (root != NULL &&
+ entry->start > root->start && entry->end == root->end) {
+ if (root->max_free == vm_map_entry_max_free_right(root, rlist))
+ root->max_free =
+ vm_map_entry_max_free_left(root, llist);
+ vm_map_splay_findnext(root, &rlist);
+ root->right= llist;
+ llist = root;
+ llist->end = entry->start;
+ } else
+ KASSERT(root == NULL,
+ ("vm_map_entry_link: inserting range [%jx, %jx) improperly"
+ " overlaps mapped range [%jx, %jx)",
+ (uintmax_t)entry->start, (uintmax_t)entry->end,
+ (uintmax_t)root->start, (uintmax_t)root->end));
+ entry->prev = llist;
+ entry->next = rlist;
+ llist->next = rlist->prev = entry;
+ entry->left = entry->right = NULL;
+ vm_map_splay_merge(entry, llist, rlist);
map->root = entry;
VM_MAP_ASSERT_CONSISTENT(map);
}
@@ -1188,12 +1240,9 @@
vm_map_entry_t llist, rlist, root, y;
VM_MAP_ASSERT_LOCKED(map);
- llist = entry->prev;
- rlist = entry->next;
- llist->next = rlist;
- rlist->prev = llist;
- root = map->root;
- root = vm_map_splay_split(entry->start, 0, root, &llist, &rlist);
+ VM_MAP_ASSERT_CONSISTENT(map);
+ llist = rlist = &map->header;
+ root = vm_map_splay_split(entry->start, 0, map->root, &llist, &rlist);
KASSERT(root != NULL,
("vm_map_entry_unlink: unlink object not mapped"));
@@ -1218,11 +1267,11 @@
case UNLINK_MERGE_NONE:
vm_map_splay_findprev(root, &llist);
vm_map_splay_findnext(root, &rlist);
- if (llist != NULL) {
+ if ((llist->eflags & MAP_ENTRY_HEADER) == 0) {
root = llist;
llist = root->right;
root->right = NULL;
- } else if (rlist != NULL) {
+ } else if ((rlist->eflags & MAP_ENTRY_HEADER) == 0) {
root = rlist;
rlist = root->left;
root->left = NULL;
@@ -1230,9 +1279,11 @@
root = NULL;
break;
}
+ y = entry->next;
+ y->prev = entry->prev;
+ y->prev->next = y;
if (root != NULL)
- root = vm_map_splay_merge(root, llist, rlist,
- root->left, root->right);
+ vm_map_splay_merge(root, llist, rlist);
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
map->nentries--;
@@ -1256,15 +1307,16 @@
vm_map_entry_t llist, rlist, root;
VM_MAP_ASSERT_LOCKED(map);
- root = map->root;
- root = vm_map_splay_split(entry->start, 0, root, &llist, &rlist);
+ VM_MAP_ASSERT_CONSISTENT(map);
+ llist = rlist = &map->header;
+ root = vm_map_splay_split(entry->start, 0, map->root, &llist, &rlist);
KASSERT(root != NULL,
("vm_map_entry_resize_free: resize_free object not mapped"));
vm_map_splay_findnext(root, &rlist);
root->right = NULL;
entry->end += grow_amount;
- map->root = vm_map_splay_merge(root, llist, rlist,
- root->left, root->right);
+ vm_map_splay_merge(root, llist, rlist);
+ map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
CTR3(KTR_VM, "vm_map_entry_resize_free: map %p, nentries %d, entry %p",
map, map->nentries, entry);
@@ -1310,8 +1362,7 @@
* change the map. Thus, the map's timestamp need not change
* on a temporary upgrade.
*/
- map->root = cur = vm_map_entry_splay(address, cur);
- VM_MAP_ASSERT_CONSISTENT(map);
+ cur = vm_map_splay(address, map);
if (!locked)
sx_downgrade(&map->lock);
@@ -1598,11 +1649,12 @@
* After splay, if start comes before root node, then there
* must be a gap from start to the root.
*/
- root = vm_map_splay_split(start, length, map->root,
- &llist, &rlist);
+ VM_MAP_ASSERT_CONSISTENT(map);
+ llist = rlist = &map->header;
+ root = vm_map_splay_split(start, length, map->root, &llist, &rlist);
if (root != NULL)
start = root->end;
- else if (rlist != NULL) {
+ else if ((rlist->eflags & MAP_ENTRY_HEADER) == 0) {
root = rlist;
rlist = root->left;
root->left = NULL;
@@ -1611,8 +1663,8 @@
llist = root->right;
root->right = NULL;
}
- map->root = vm_map_splay_merge(root, llist, rlist,
- root->left, root->right);
+ vm_map_splay_merge(root, llist, rlist);
+ map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
if (start + length <= root->start)
return (start);
@@ -1633,39 +1685,33 @@
/*
* Splay for the least large-enough gap in the right subtree.
*/
- llist = NULL;
- rlist = NULL;
+ llist = rlist = &map->header;
for (left_length = 0; ;
- left_length = root->left != NULL ?
- root->left->max_free : root->start - llist->end) {
+ left_length = vm_map_entry_max_free_left(root, llist)) {
if (length <= left_length)
- SPLAY_LEFT_STEP(root, y, rlist,
- length <= (y->left != NULL ?
- y->left->max_free : y->start - llist->end));
+ SPLAY_LEFT_STEP(root, y, llist, rlist,
+ length <= vm_map_entry_max_free_left(y, llist));
else
- SPLAY_RIGHT_STEP(root, y, llist,
- length > (y->left != NULL ?
- y->left->max_free : y->start - root->end));
+ SPLAY_RIGHT_STEP(root, y, llist, rlist,
+ length > vm_map_entry_max_free_left(y, root));
if (root == NULL)
break;
}
root = llist;
llist = root->right;
- if ((y = rlist) == NULL)
+ if (rlist == &map->header)
root->right = NULL;
else {
+ y = rlist;
rlist = y->left;
+ vm_map_splay_merge(y, &map->header, rlist);
y->left = NULL;
- root->right = y->right;
- }
- root = vm_map_splay_merge(root, llist, rlist,
- root->left, root->right);
- if (y != NULL) {
- y->right = root->right;
- vm_map_entry_set_max_free(y);
+ y->max_free = MAX(
+ vm_map_entry_max_free_left(y, root),
+ vm_map_entry_max_free_right(y, &map->header));
root->right = y;
- vm_map_entry_set_max_free(root);
}
+ vm_map_splay_merge(root, llist, &map->header);
map->root = root;
VM_MAP_ASSERT_CONSISTENT(map);
return (root->end);
@@ -2128,8 +2174,6 @@
*new_entry = *entry;
new_entry->end = start;
- entry->offset += (start - entry->start);
- entry->start = start;
if (new_entry->cred != NULL)
crhold(entry->cred);
@@ -2211,7 +2255,7 @@
new_entry = vm_map_entry_create(map);
*new_entry = *entry;
- new_entry->start = entry->end = end;
+ new_entry->start = end;
new_entry->offset += (end - entry->start);
if (new_entry->cred != NULL)
crhold(entry->cred);

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