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Index: head/sys/vm/vm_object.c
===================================================================
--- head/sys/vm/vm_object.c
+++ head/sys/vm/vm_object.c
@@ -1097,7 +1097,7 @@
*/
void
vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end,
- int advise)
+ int advice)
{
vm_pindex_t tpindex;
vm_object_t backing_object, tobject;
@@ -1105,11 +1105,9 @@
if (object == NULL)
return;
+
VM_OBJECT_WLOCK(object);
- /*
- * Locate and adjust resident pages
- */
- for (; pindex < end; pindex += 1) {
+ for (m = NULL; pindex < end; pindex++) {
relookup:
tobject = object;
tpindex = pindex;
@@ -1118,7 +1116,7 @@
* MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
* and those pages must be OBJ_ONEMAPPING.
*/
- if (advise == MADV_FREE) {
+ if (advice == MADV_FREE) {
if ((tobject->type != OBJT_DEFAULT &&
tobject->type != OBJT_SWAP) ||
(tobject->flags & OBJ_ONEMAPPING) == 0) {
@@ -1126,15 +1124,29 @@
}
} else if ((tobject->flags & OBJ_UNMANAGED) != 0)
goto unlock_tobject;
- m = vm_page_lookup(tobject, tpindex);
- if (m == NULL) {
- /*
- * There may be swap even if there is no backing page
- */
- if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
+
+ /*
+ * In the common case where the object has no backing object, we
+ * can avoid performing lookups at each pindex. In either case,
+ * when applying MADV_FREE we take care to release any swap
+ * space used to store non-resident pages.
+ */
+ if (object->backing_object == NULL) {
+ m = (m != NULL) ? TAILQ_NEXT(m, listq) :
+ vm_page_find_least(object, pindex);
+ tpindex = (m != NULL && m->pindex < end) ?
+ m->pindex : end;
+ if (advice == MADV_FREE && object->type == OBJT_SWAP &&
+ tpindex > pindex)
+ swap_pager_freespace(object, pindex,
+ tpindex - pindex);
+ if ((pindex = tpindex) == end)
+ break;
+ } else if ((m = vm_page_lookup(tobject, tpindex)) == NULL) {
+ if (advice == MADV_FREE && tobject->type == OBJT_SWAP)
swap_pager_freespace(tobject, tpindex, 1);
/*
- * next object
+ * Prepare to search the next object in the chain.
*/
backing_object = tobject->backing_object;
if (backing_object == NULL)
@@ -1145,11 +1157,13 @@
VM_OBJECT_WUNLOCK(tobject);
tobject = backing_object;
goto shadowlookup;
- } else if (m->valid != VM_PAGE_BITS_ALL)
- goto unlock_tobject;
+ }
+
/*
* If the page is not in a normal state, skip it.
*/
+ if (m->valid != VM_PAGE_BITS_ALL)
+ goto unlock_tobject;
vm_page_lock(m);
if (m->hold_count != 0 || m->wire_count != 0) {
vm_page_unlock(m);
@@ -1160,7 +1174,7 @@
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
("vm_object_madvise: page %p is not managed", m));
if (vm_page_busied(m)) {
- if (advise == MADV_WILLNEED) {
+ if (advice == MADV_WILLNEED) {
/*
* Reference the page before unlocking and
* sleeping so that the page daemon is less
@@ -1172,21 +1186,18 @@
VM_OBJECT_WUNLOCK(object);
VM_OBJECT_WUNLOCK(tobject);
vm_page_busy_sleep(m, "madvpo", false);
+ m = NULL;
VM_OBJECT_WLOCK(object);
goto relookup;
}
- if (advise == MADV_WILLNEED) {
- vm_page_activate(m);
- } else {
- vm_page_advise(m, advise);
- }
+ vm_page_advise(m, advice);
vm_page_unlock(m);
- if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
+ if (advice == MADV_FREE && tobject->type == OBJT_SWAP)
swap_pager_freespace(tobject, tpindex, 1);
unlock_tobject:
if (tobject != object)
VM_OBJECT_WUNLOCK(tobject);
- }
+ }
VM_OBJECT_WUNLOCK(object);
}
Index: head/sys/vm/vm_page.c
===================================================================
--- head/sys/vm/vm_page.c
+++ head/sys/vm/vm_page.c
@@ -3002,7 +3002,7 @@
/*
* vm_page_advise
*
- * Deactivate or do nothing, as appropriate.
+ * Apply the specified advice to the given page.
*
* The object and page must be locked.
*/
@@ -3020,8 +3020,11 @@
* would result in a page fault on a later access.
*/
vm_page_undirty(m);
- else if (advice != MADV_DONTNEED)
+ else if (advice != MADV_DONTNEED) {
+ if (advice == MADV_WILLNEED)
+ vm_page_activate(m);
return;
+ }
/*
* Clear any references to the page. Otherwise, the page daemon will

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