Author: alc
Date: Sat Apr 27 16:44:59 2013
New Revision: 249986
URL: http://svnweb.freebsd.org/changeset/base/249986
Log:
Avoid some lookup restarts in vm_radix_lookup_{ge,le}().
Sponsored by: EMC / Isilon Storage Division
Modified:
head/sys/vm/vm_radix.c
Modified: head/sys/vm/vm_radix.c
==============================================================================
--- head/sys/vm/vm_radix.c Sat Apr 27 14:21:36 2013 (r249985)
+++ head/sys/vm/vm_radix.c Sat Apr 27 16:44:59 2013 (r249986)
@@ -527,26 +527,26 @@ restart:
maplevels[rnode->rn_clev] = TRUE;
/*
- * If the keys differ before the current bisection node
- * the search key might rollback to the earliest
- * available bisection node, or to the smaller value
- * in the current domain (if the owner is bigger than the
+ * If the keys differ before the current bisection node,
+ * then the search key might rollback to the earliest
+ * available bisection node or to the smallest key
+ * in the current node (if the owner is bigger than the
* search key).
* The maplevels array records any node has been seen
* at a given level. This aids the search for a valid
* bisection node.
*/
if (vm_radix_keybarr(rnode, index)) {
- difflev = vm_radix_keydiff(index, rnode->rn_owner);
if (index > rnode->rn_owner) {
+ difflev = vm_radix_keydiff(index,
+ rnode->rn_owner);
if (vm_radix_addlev(&index, maplevels,
difflev) > 0)
break;
+ rnode = vm_radix_getroot(rtree);
+ goto restart;
} else
- index = vm_radix_trimkey(rnode->rn_owner,
- difflev);
- rnode = vm_radix_getroot(rtree);
- goto restart;
+ index = rnode->rn_owner;
}
slot = vm_radix_slot(index, rnode->rn_clev);
child = rnode->rn_child[slot];
@@ -628,26 +628,28 @@ restart:
maplevels[rnode->rn_clev] = TRUE;
/*
- * If the keys differ before the current bisection node
- * the search key might rollback to the earliest
- * available bisection node, or to the higher value
- * in the current domain (if the owner is smaller than the
+ * If the keys differ before the current bisection node,
+ * then the search key might rollback to the earliest
+ * available bisection node or to the largest key
+ * in the current node (if the owner is smaller than the
* search key).
* The maplevels array records any node has been seen
* at a given level. This aids the search for a valid
* bisection node.
*/
if (vm_radix_keybarr(rnode, index)) {
- difflev = vm_radix_keydiff(index, rnode->rn_owner);
if (index > rnode->rn_owner) {
- index = vm_radix_trimkey(rnode->rn_owner,
- difflev);
- index |= VM_RADIX_UNITLEVEL(difflev) - 1;
- } else if (vm_radix_declev(&index, maplevels,
- difflev) > 0)
- break;
- rnode = vm_radix_getroot(rtree);
- goto restart;
+ index = rnode->rn_owner + VM_RADIX_COUNT *
+ VM_RADIX_UNITLEVEL(rnode->rn_clev) - 1;
+ } else {
+ difflev = vm_radix_keydiff(index,
+ rnode->rn_owner);
+ if (vm_radix_declev(&index, maplevels,
+ difflev) > 0)
+ break;
+ rnode = vm_radix_getroot(rtree);
+ goto restart;
+ }
}
slot = vm_radix_slot(index, rnode->rn_clev);
child = rnode->rn_child[slot];
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