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Move the implementation of the vm map's fast path on address lookup from

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vm_map_lookup{,_locked}() to vm_map_lookup_entry().  Having the fast path
in vm_map_lookup{,_locked}() limits its benefits to page faults.  Moving
it to vm_map_lookup_entry() extends its benefits to other operations on
the vm map.
This commit is contained in:
Alan Cox 2008-12-30 19:48:03 +00:00
parent 0b8454a9a0
commit 4c3ef59e3d
1 changed files with 23 additions and 34 deletions
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57
sys/vm/vm_map.c
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@ -901,12 +901,24 @@ vm_map_lookup_entry(
{
vm_map_entry_t cur;
cur = vm_map_entry_splay(address, map->root);
/*
* If the map is empty, then the map entry immediately preceding
* "address" is the map's header.
*/
cur = map->root;
if (cur == NULL)
*entry = &map->header;
else {
map->root = cur;
else if (address >= cur->start && cur->end > address) {
*entry = cur;
return (TRUE);
} else {
map->root = cur = vm_map_entry_splay(address, cur);
/*
* If "address" is contained within a map entry, the new root
* is that map entry. Otherwise, the new root is a map entry
* immediately before or after "address".
*/
if (address >= cur->start) {
*entry = cur;
if (cur->end > address)
@ -3108,9 +3120,6 @@ vm_map_lookup(vm_map_t *var_map, /* IN/OUT */
vm_prot_t fault_type = fault_typea;
RetryLookup:;
/*
* Lookup the faulting address.
*/
vm_map_lock_read(map);
#define RETURN(why) \
@ -3120,22 +3129,12 @@ RetryLookup:;
}
/*
* If the map has an interesting hint, try it before calling full
* blown lookup routine.
* Lookup the faulting address.
*/
entry = map->root;
*out_entry = entry;
if (entry == NULL ||
(vaddr < entry->start) || (vaddr >= entry->end)) {
/*
* Entry was either not a valid hint, or the vaddr was not
* contained in the entry, so do a full lookup.
*/
if (!vm_map_lookup_entry(map, vaddr, out_entry))
RETURN(KERN_INVALID_ADDRESS);
if (!vm_map_lookup_entry(map, vaddr, out_entry))
RETURN(KERN_INVALID_ADDRESS);
entry = *out_entry;
}
entry = *out_entry;
/*
* Handle submaps.
@ -3262,22 +3261,12 @@ vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
vm_prot_t fault_type = fault_typea;
/*
* If the map has an interesting hint, try it before calling full
* blown lookup routine.
* Lookup the faulting address.
*/
entry = map->root;
*out_entry = entry;
if (entry == NULL ||
(vaddr < entry->start) || (vaddr >= entry->end)) {
/*
* Entry was either not a valid hint, or the vaddr was not
* contained in the entry, so do a full lookup.
*/
if (!vm_map_lookup_entry(map, vaddr, out_entry))
return (KERN_INVALID_ADDRESS);
if (!vm_map_lookup_entry(map, vaddr, out_entry))
return (KERN_INVALID_ADDRESS);
entry = *out_entry;
}
entry = *out_entry;
/*
* Fail if the entry refers to a submap.