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Correct two optimization errors in vm_object_page_remove:

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1. The size of vm_object::memq is vm_object::resident_page_count,
not vm_object::size.

2. The "size > 4" test sometimes results in the traversal of a ~1000 page
memq in order to locate ~10 pages.
This commit is contained in:
alc 1999-03-14 06:36:00 +00:00
parent 61a6296116
commit aa8bb4e29a
1 changed files with 4 additions and 3 deletions
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7
sys/vm/vm_object.c
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@ -61,7 +61,7 @@
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: vm_object.c,v 1.151 1999/02/15 02:03:40 dillon Exp $
* $Id: vm_object.c,v 1.152 1999/02/24 21:26:26 dillon Exp $
*/
/*
@ -1346,7 +1346,8 @@ vm_object_page_remove(object, start, end, clean_only)
unsigned int size;
int all;
if (object == NULL)
if (object == NULL ||
object->resident_page_count == 0)
return;
all = ((end == 0) && (start == 0));
@ -1354,7 +1355,7 @@ vm_object_page_remove(object, start, end, clean_only)
vm_object_pip_add(object, 1);
again:
size = end - start;
if (all || size > 4 || size >= object->size / 4) {
if (all || size > object->resident_page_count / 4) {
for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
next = TAILQ_NEXT(p, listq);
if (all || ((start <= p->pindex) && (p->pindex < end))) {