Although we perform path compression to reduce the height of the trie and
the number of interior nodes, we have previously created a level zero interior node at the root of every non-empty trie, even when that node is not strictly necessary, i.e., it has only one child. This change is the second (and final) step in eliminating those unnecessary level zero interior nodes. Specifically, it updates the deletion and insertion functions so that they do not require a level zero interior node at the root of the trie. For a "buildworld" workload, this change results in a 16.8% reduction in the number of interior nodes allocated and a similar reduction in the average execution time for lookup functions. For example, the average execution time for a call to vm_radix_lookup_ge() is reduced by 22.9%. Reviewed by: attilio, jeff (an earlier version) Sponsored by: EMC / Isilon Storage Division
This commit is contained in:
parent
44246b4c36
commit
a08f2cf69e
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=249502
@ -396,7 +396,8 @@ void
|
||||
vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
|
||||
{
|
||||
vm_pindex_t index, newind;
|
||||
struct vm_radix_node *parent, *rnode, *tmp;
|
||||
void **parentp;
|
||||
struct vm_radix_node *rnode, *tmp;
|
||||
vm_page_t m;
|
||||
int slot;
|
||||
uint16_t clev;
|
||||
@ -409,34 +410,34 @@ vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
|
||||
*/
|
||||
rnode = vm_radix_getroot(rtree);
|
||||
if (rnode == NULL) {
|
||||
rnode = vm_radix_node_get(0, 1, 0);
|
||||
vm_radix_setroot(rtree, rnode);
|
||||
vm_radix_addpage(rnode, index, 0, page);
|
||||
rtree->rt_root = (uintptr_t)page | VM_RADIX_ISLEAF;
|
||||
return;
|
||||
}
|
||||
do {
|
||||
slot = vm_radix_slot(index, rnode->rn_clev);
|
||||
if (vm_radix_isleaf(rnode->rn_child[slot])) {
|
||||
m = vm_radix_topage(rnode->rn_child[slot]);
|
||||
parentp = (void **)&rtree->rt_root;
|
||||
for (;;) {
|
||||
if (vm_radix_isleaf(rnode)) {
|
||||
m = vm_radix_topage(rnode);
|
||||
if (m->pindex == index)
|
||||
panic("%s: key %jx is already present",
|
||||
__func__, (uintmax_t)index);
|
||||
clev = vm_radix_keydiff(m->pindex, index);
|
||||
tmp = vm_radix_node_get(vm_radix_trimkey(index,
|
||||
clev - 1), 2, clev);
|
||||
rnode->rn_child[slot] = tmp;
|
||||
*parentp = tmp;
|
||||
vm_radix_addpage(tmp, index, clev, page);
|
||||
vm_radix_addpage(tmp, m->pindex, clev, m);
|
||||
return;
|
||||
}
|
||||
} else if (vm_radix_keybarr(rnode, index))
|
||||
break;
|
||||
slot = vm_radix_slot(index, rnode->rn_clev);
|
||||
if (rnode->rn_child[slot] == NULL) {
|
||||
rnode->rn_count++;
|
||||
vm_radix_addpage(rnode, index, rnode->rn_clev, page);
|
||||
return;
|
||||
}
|
||||
parent = rnode;
|
||||
parentp = &rnode->rn_child[slot];
|
||||
rnode = rnode->rn_child[slot];
|
||||
} while (!vm_radix_keybarr(rnode, index));
|
||||
}
|
||||
|
||||
/*
|
||||
* A new node is needed because the right insertion level is reached.
|
||||
@ -447,7 +448,7 @@ vm_radix_insert(struct vm_radix *rtree, vm_page_t page)
|
||||
clev = vm_radix_keydiff(newind, index);
|
||||
tmp = vm_radix_node_get(vm_radix_trimkey(index, clev - 1), 2,
|
||||
clev);
|
||||
parent->rn_child[slot] = tmp;
|
||||
*parentp = tmp;
|
||||
vm_radix_addpage(tmp, index, clev, page);
|
||||
slot = vm_radix_slot(newind, clev);
|
||||
tmp->rn_child[slot] = rnode;
|
||||
@ -694,8 +695,15 @@ vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
|
||||
vm_page_t m;
|
||||
int i, slot;
|
||||
|
||||
parent = NULL;
|
||||
rnode = vm_radix_getroot(rtree);
|
||||
if (vm_radix_isleaf(rnode)) {
|
||||
m = vm_radix_topage(rnode);
|
||||
if (m->pindex != index)
|
||||
panic("%s: invalid key found", __func__);
|
||||
vm_radix_setroot(rtree, NULL);
|
||||
return;
|
||||
}
|
||||
parent = NULL;
|
||||
for (;;) {
|
||||
if (rnode == NULL)
|
||||
panic("vm_radix_remove: impossible to locate the key");
|
||||
@ -708,22 +716,19 @@ vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index)
|
||||
rnode->rn_count--;
|
||||
if (rnode->rn_count > 1)
|
||||
break;
|
||||
if (parent == NULL) {
|
||||
if (rnode->rn_count == 0) {
|
||||
vm_radix_node_put(rnode);
|
||||
vm_radix_setroot(rtree, NULL);
|
||||
}
|
||||
break;
|
||||
}
|
||||
for (i = 0; i < VM_RADIX_COUNT; i++)
|
||||
if (rnode->rn_child[i] != NULL)
|
||||
break;
|
||||
KASSERT(i != VM_RADIX_COUNT,
|
||||
("%s: invalid node configuration", __func__));
|
||||
slot = vm_radix_slot(index, parent->rn_clev);
|
||||
KASSERT(parent->rn_child[slot] == rnode,
|
||||
("%s: invalid child value", __func__));
|
||||
parent->rn_child[slot] = rnode->rn_child[i];
|
||||
if (parent == NULL)
|
||||
vm_radix_setroot(rtree, rnode->rn_child[i]);
|
||||
else {
|
||||
slot = vm_radix_slot(index, parent->rn_clev);
|
||||
KASSERT(parent->rn_child[slot] == rnode,
|
||||
("%s: invalid child value", __func__));
|
||||
parent->rn_child[slot] = rnode->rn_child[i];
|
||||
}
|
||||
rnode->rn_count--;
|
||||
rnode->rn_child[i] = NULL;
|
||||
vm_radix_node_put(rnode);
|
||||
@ -748,7 +753,8 @@ vm_radix_reclaim_allnodes(struct vm_radix *rtree)
|
||||
if (root == NULL)
|
||||
return;
|
||||
vm_radix_setroot(rtree, NULL);
|
||||
vm_radix_reclaim_allnodes_int(root);
|
||||
if (!vm_radix_isleaf(root))
|
||||
vm_radix_reclaim_allnodes_int(root);
|
||||
}
|
||||
|
||||
#ifdef DDB
|
||||
|
Loading…
Reference in New Issue
Block a user