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Code Issues Releases Activity

Fix a problem with the pageout daemon RSS limiting, where it degrades

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performance to LRU or worse when RSS limiting takes effect.  Also,
make an end condition in the active queue scan more efficient in the
case where pages are removed from the active queue as a side effect
of a pmap operation.
This commit is contained in:
John Dyson 1996-07-08 02:25:53 +00:00
parent 1b4a0206d6
commit c8c4b40cca
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=17003
1 changed files with 27 additions and 21 deletions
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48
sys/vm/vm_pageout.c
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@ -65,7 +65,7 @@
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: vm_pageout.c,v 1.79 1996/06/26 05:39:26 dyson Exp $
* $Id: vm_pageout.c,v 1.80 1996/06/29 09:15:39 davidg Exp $
*/
/*
@ -446,30 +446,30 @@ vm_pageout_object_deactivate_pages(map, object, desired, map_remove_only)
continue;
}
if ((p->flags & PG_REFERENCED) == 0) {
refcount = pmap_ts_referenced(VM_PAGE_TO_PHYS(p));
if (refcount) {
p->act_count += refcount - 1;
p->flags |= PG_REFERENCED;
}
} else {
pmap_clear_reference(VM_PAGE_TO_PHYS(p));
refcount = pmap_ts_referenced(VM_PAGE_TO_PHYS(p));
if (refcount) {
p->flags |= PG_REFERENCED;
} else if (p->flags & PG_REFERENCED) {
refcount = 1;
}
if ((p->queue != PQ_ACTIVE) &&
(p->flags & PG_REFERENCED)) {
vm_page_activate(p);
}
/*
* if a page is active, not wired and is in the processes
* pmap, then deactivate the page.
*/
if (p->queue == PQ_ACTIVE) {
p->act_count += refcount;
p->flags &= ~PG_REFERENCED;
} else if (p->queue == PQ_ACTIVE) {
if ((p->flags & PG_REFERENCED) == 0) {
vm_page_protect(p, VM_PROT_NONE);
if (!remove_mode)
p->act_count -= min(p->act_count, ACT_DECLINE);
if (!remove_mode && (vm_pageout_algorithm_lru || (p->act_count == 0))) {
vm_page_protect(p, VM_PROT_NONE);
vm_page_deactivate(p);
} else {
s = splvm();
TAILQ_REMOVE(&vm_page_queue_active, p, pageq);
TAILQ_INSERT_TAIL(&vm_page_queue_active, p, pageq);
splx(s);
}
} else {
p->flags &= ~PG_REFERENCED;
if (p->act_count < (ACT_MAX - ACT_ADVANCE))
@ -564,7 +564,7 @@ vm_pageout_map_deactivate_pages(map, desired)
static int
vm_pageout_scan()
{
vm_page_t m, next;
vm_page_t m, next, nextnext;
int page_shortage, addl_page_shortage, maxscan, maxlaunder, pcount;
int pages_freed;
struct proc *p, *bigproc;
@ -753,17 +753,23 @@ vm_pageout_scan()
page_shortage += addl_page_shortage;
}
pcount = cnt.v_active_count;
m = TAILQ_FIRST(&vm_page_queue_active);
nextnext = NULL;
while ((m != NULL) && (pcount-- > 0) && (page_shortage > 0)) {
int refcount;
if (m->queue != PQ_ACTIVE) {
break;
m = nextnext;
if ((m == NULL) || (m->queue != PQ_ACTIVE))
break;
}
next = TAILQ_NEXT(m, pageq);
if (next)
nextnext = TAILQ_NEXT(next, pageq);
else
nextnext = NULL;
/*
* Don't deactivate pages that are busy.