990 lines
25 KiB
C
990 lines
25 KiB
C
/*
|
|
* Copyright (c) 1991 Regents of the University of California.
|
|
* All rights reserved.
|
|
* Copyright (c) 1994 John S. Dyson
|
|
* All rights reserved.
|
|
* Copyright (c) 1994 David Greenman
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* The Mach Operating System project at Carnegie-Mellon University.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* from: @(#)vm_pageout.c 7.4 (Berkeley) 5/7/91
|
|
*
|
|
*
|
|
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and
|
|
* its documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
|
|
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie the
|
|
* rights to redistribute these changes.
|
|
*
|
|
* $Id: vm_pageout.c,v 1.61 1995/12/07 12:48:24 davidg Exp $
|
|
*/
|
|
|
|
/*
|
|
* The proverbial page-out daemon.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/signalvar.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/vmmeter.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_prot.h>
|
|
#include <vm/lock.h>
|
|
#include <vm/vm_object.h>
|
|
#include <vm/vm_page.h>
|
|
#include <vm/vm_map.h>
|
|
#include <vm/vm_pageout.h>
|
|
#include <vm/vm_kern.h>
|
|
#include <vm/vm_pager.h>
|
|
#include <vm/swap_pager.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
/*
|
|
* System initialization
|
|
*/
|
|
|
|
/* the kernel process "vm_pageout"*/
|
|
static void vm_pageout __P((void));
|
|
static int vm_pageout_clean __P((vm_page_t, int));
|
|
static int vm_pageout_scan __P((void));
|
|
struct proc *pageproc;
|
|
|
|
static struct kproc_desc page_kp = {
|
|
"pagedaemon",
|
|
vm_pageout,
|
|
&pageproc
|
|
};
|
|
SYSINIT_KT(pagedaemon, SI_SUB_KTHREAD_PAGE, SI_ORDER_FIRST, kproc_start, &page_kp)
|
|
|
|
/* the kernel process "vm_daemon"*/
|
|
static void vm_daemon __P((void));
|
|
struct proc *vmproc;
|
|
|
|
static struct kproc_desc vm_kp = {
|
|
"vmdaemon",
|
|
vm_daemon,
|
|
&vmproc
|
|
};
|
|
SYSINIT_KT(vmdaemon, SI_SUB_KTHREAD_VM, SI_ORDER_FIRST, kproc_start, &vm_kp)
|
|
|
|
|
|
int vm_pages_needed; /* Event on which pageout daemon sleeps */
|
|
|
|
int vm_pageout_pages_needed; /* flag saying that the pageout daemon needs pages */
|
|
|
|
extern int npendingio;
|
|
int vm_pageout_req_swapout; /* XXX */
|
|
int vm_daemon_needed;
|
|
extern int nswiodone;
|
|
extern int vm_swap_size;
|
|
extern int vfs_update_wakeup;
|
|
|
|
#define MAXSCAN 1024 /* maximum number of pages to scan in queues */
|
|
|
|
#define MAXLAUNDER (cnt.v_page_count > 1800 ? 32 : 16)
|
|
|
|
#define VM_PAGEOUT_PAGE_COUNT 16
|
|
int vm_pageout_page_count = VM_PAGEOUT_PAGE_COUNT;
|
|
|
|
int vm_page_max_wired; /* XXX max # of wired pages system-wide */
|
|
|
|
typedef int freeer_fcn_t __P((vm_map_t, vm_object_t, int, int));
|
|
static void vm_pageout_map_deactivate_pages __P((vm_map_t, vm_map_entry_t,
|
|
int *, freeer_fcn_t *));
|
|
static freeer_fcn_t vm_pageout_object_deactivate_pages;
|
|
static void vm_req_vmdaemon __P((void));
|
|
|
|
/*
|
|
* vm_pageout_clean:
|
|
*
|
|
* Clean the page and remove it from the laundry.
|
|
*
|
|
* We set the busy bit to cause potential page faults on this page to
|
|
* block.
|
|
*
|
|
* And we set pageout-in-progress to keep the object from disappearing
|
|
* during pageout. This guarantees that the page won't move from the
|
|
* inactive queue. (However, any other page on the inactive queue may
|
|
* move!)
|
|
*/
|
|
static int
|
|
vm_pageout_clean(m, sync)
|
|
vm_page_t m;
|
|
int sync;
|
|
{
|
|
register vm_object_t object;
|
|
vm_page_t mc[2*VM_PAGEOUT_PAGE_COUNT];
|
|
int pageout_count;
|
|
int i, forward_okay, backward_okay, page_base;
|
|
vm_pindex_t pindex = m->pindex;
|
|
|
|
object = m->object;
|
|
|
|
/*
|
|
* If not OBJT_SWAP, additional memory may be needed to do the pageout.
|
|
* Try to avoid the deadlock.
|
|
*/
|
|
if ((sync != VM_PAGEOUT_FORCE) &&
|
|
(object->type != OBJT_SWAP) &&
|
|
((cnt.v_free_count + cnt.v_cache_count) < cnt.v_pageout_free_min))
|
|
return 0;
|
|
|
|
/*
|
|
* Don't mess with the page if it's busy.
|
|
*/
|
|
if ((!sync && m->hold_count != 0) ||
|
|
((m->busy != 0) || (m->flags & PG_BUSY)))
|
|
return 0;
|
|
|
|
/*
|
|
* Try collapsing before it's too late.
|
|
*/
|
|
if (!sync && object->backing_object) {
|
|
vm_object_collapse(object);
|
|
}
|
|
mc[VM_PAGEOUT_PAGE_COUNT] = m;
|
|
pageout_count = 1;
|
|
page_base = VM_PAGEOUT_PAGE_COUNT;
|
|
forward_okay = TRUE;
|
|
if (pindex != 0)
|
|
backward_okay = TRUE;
|
|
else
|
|
backward_okay = FALSE;
|
|
/*
|
|
* Scan object for clusterable pages.
|
|
*
|
|
* We can cluster ONLY if: ->> the page is NOT
|
|
* clean, wired, busy, held, or mapped into a
|
|
* buffer, and one of the following:
|
|
* 1) The page is inactive, or a seldom used
|
|
* active page.
|
|
* -or-
|
|
* 2) we force the issue.
|
|
*/
|
|
for (i = 1; (i < vm_pageout_page_count) && (forward_okay || backward_okay); i++) {
|
|
vm_page_t p;
|
|
|
|
/*
|
|
* See if forward page is clusterable.
|
|
*/
|
|
if (forward_okay) {
|
|
/*
|
|
* Stop forward scan at end of object.
|
|
*/
|
|
if ((pindex + i) > object->size) {
|
|
forward_okay = FALSE;
|
|
goto do_backward;
|
|
}
|
|
p = vm_page_lookup(object, pindex + i);
|
|
if (p) {
|
|
if ((p->flags & (PG_BUSY|PG_CACHE)) || p->busy) {
|
|
forward_okay = FALSE;
|
|
goto do_backward;
|
|
}
|
|
vm_page_test_dirty(p);
|
|
if ((p->dirty & p->valid) != 0 &&
|
|
((p->flags & PG_INACTIVE) ||
|
|
(sync == VM_PAGEOUT_FORCE)) &&
|
|
(p->wire_count == 0) &&
|
|
(p->hold_count == 0)) {
|
|
mc[VM_PAGEOUT_PAGE_COUNT + i] = p;
|
|
pageout_count++;
|
|
if (pageout_count == vm_pageout_page_count)
|
|
break;
|
|
} else {
|
|
forward_okay = FALSE;
|
|
}
|
|
} else {
|
|
forward_okay = FALSE;
|
|
}
|
|
}
|
|
do_backward:
|
|
/*
|
|
* See if backward page is clusterable.
|
|
*/
|
|
if (backward_okay) {
|
|
/*
|
|
* Stop backward scan at beginning of object.
|
|
*/
|
|
if ((pindex - i) == 0) {
|
|
backward_okay = FALSE;
|
|
}
|
|
p = vm_page_lookup(object, pindex - i);
|
|
if (p) {
|
|
if ((p->flags & (PG_BUSY|PG_CACHE)) || p->busy) {
|
|
backward_okay = FALSE;
|
|
continue;
|
|
}
|
|
vm_page_test_dirty(p);
|
|
if ((p->dirty & p->valid) != 0 &&
|
|
((p->flags & PG_INACTIVE) ||
|
|
(sync == VM_PAGEOUT_FORCE)) &&
|
|
(p->wire_count == 0) &&
|
|
(p->hold_count == 0)) {
|
|
mc[VM_PAGEOUT_PAGE_COUNT - i] = p;
|
|
pageout_count++;
|
|
page_base--;
|
|
if (pageout_count == vm_pageout_page_count)
|
|
break;
|
|
} else {
|
|
backward_okay = FALSE;
|
|
}
|
|
} else {
|
|
backward_okay = FALSE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we allow reads during pageouts...
|
|
*/
|
|
for (i = page_base; i < (page_base + pageout_count); i++) {
|
|
mc[i]->flags |= PG_BUSY;
|
|
vm_page_protect(mc[i], VM_PROT_READ);
|
|
}
|
|
|
|
return vm_pageout_flush(&mc[page_base], pageout_count, sync);
|
|
}
|
|
|
|
int
|
|
vm_pageout_flush(mc, count, sync)
|
|
vm_page_t *mc;
|
|
int count;
|
|
int sync;
|
|
{
|
|
register vm_object_t object;
|
|
int pageout_status[count];
|
|
int anyok = 0;
|
|
int i;
|
|
|
|
object = mc[0]->object;
|
|
object->paging_in_progress += count;
|
|
|
|
vm_pager_put_pages(object, mc, count,
|
|
((sync || (object == kernel_object)) ? TRUE : FALSE),
|
|
pageout_status);
|
|
|
|
|
|
for (i = 0; i < count; i++) {
|
|
vm_page_t mt = mc[i];
|
|
|
|
switch (pageout_status[i]) {
|
|
case VM_PAGER_OK:
|
|
++anyok;
|
|
break;
|
|
case VM_PAGER_PEND:
|
|
++anyok;
|
|
break;
|
|
case VM_PAGER_BAD:
|
|
/*
|
|
* Page outside of range of object. Right now we
|
|
* essentially lose the changes by pretending it
|
|
* worked.
|
|
*/
|
|
pmap_clear_modify(VM_PAGE_TO_PHYS(mt));
|
|
mt->dirty = 0;
|
|
break;
|
|
case VM_PAGER_ERROR:
|
|
case VM_PAGER_FAIL:
|
|
/*
|
|
* If page couldn't be paged out, then reactivate the
|
|
* page so it doesn't clog the inactive list. (We
|
|
* will try paging out it again later).
|
|
*/
|
|
if (mt->flags & PG_INACTIVE)
|
|
vm_page_activate(mt);
|
|
break;
|
|
case VM_PAGER_AGAIN:
|
|
break;
|
|
}
|
|
|
|
|
|
/*
|
|
* If the operation is still going, leave the page busy to
|
|
* block all other accesses. Also, leave the paging in
|
|
* progress indicator set so that we don't attempt an object
|
|
* collapse.
|
|
*/
|
|
if (pageout_status[i] != VM_PAGER_PEND) {
|
|
vm_object_pip_wakeup(object);
|
|
if ((mt->flags & (PG_REFERENCED|PG_WANTED)) ||
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(mt))) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(mt));
|
|
mt->flags &= ~PG_REFERENCED;
|
|
if (mt->flags & PG_INACTIVE)
|
|
vm_page_activate(mt);
|
|
}
|
|
PAGE_WAKEUP(mt);
|
|
}
|
|
}
|
|
return anyok;
|
|
}
|
|
|
|
/*
|
|
* vm_pageout_object_deactivate_pages
|
|
*
|
|
* deactivate enough pages to satisfy the inactive target
|
|
* requirements or if vm_page_proc_limit is set, then
|
|
* deactivate all of the pages in the object and its
|
|
* backing_objects.
|
|
*
|
|
* The object and map must be locked.
|
|
*/
|
|
static int
|
|
vm_pageout_object_deactivate_pages(map, object, count, map_remove_only)
|
|
vm_map_t map;
|
|
vm_object_t object;
|
|
int count;
|
|
int map_remove_only;
|
|
{
|
|
register vm_page_t p, next;
|
|
int rcount;
|
|
int dcount;
|
|
|
|
dcount = 0;
|
|
if (count == 0)
|
|
count = 1;
|
|
|
|
if (object->type == OBJT_DEVICE)
|
|
return 0;
|
|
|
|
if (object->backing_object) {
|
|
if (object->backing_object->ref_count == 1)
|
|
dcount += vm_pageout_object_deactivate_pages(map,
|
|
object->backing_object, count / 2 + 1, map_remove_only);
|
|
else
|
|
vm_pageout_object_deactivate_pages(map,
|
|
object->backing_object, count, 1);
|
|
}
|
|
if (object->paging_in_progress)
|
|
return dcount;
|
|
|
|
/*
|
|
* scan the objects entire memory queue
|
|
*/
|
|
rcount = object->resident_page_count;
|
|
p = object->memq.tqh_first;
|
|
while (p && (rcount-- > 0)) {
|
|
next = p->listq.tqe_next;
|
|
cnt.v_pdpages++;
|
|
if (p->wire_count != 0 ||
|
|
p->hold_count != 0 ||
|
|
p->busy != 0 ||
|
|
!pmap_page_exists(vm_map_pmap(map), VM_PAGE_TO_PHYS(p))) {
|
|
p = next;
|
|
continue;
|
|
}
|
|
/*
|
|
* if a page is active, not wired and is in the processes
|
|
* pmap, then deactivate the page.
|
|
*/
|
|
if ((p->flags & (PG_ACTIVE | PG_BUSY)) == PG_ACTIVE) {
|
|
if (!pmap_is_referenced(VM_PAGE_TO_PHYS(p)) &&
|
|
(p->flags & (PG_REFERENCED|PG_WANTED)) == 0) {
|
|
p->act_count -= min(p->act_count, ACT_DECLINE);
|
|
/*
|
|
* if the page act_count is zero -- then we
|
|
* deactivate
|
|
*/
|
|
if (!p->act_count) {
|
|
if (!map_remove_only)
|
|
vm_page_deactivate(p);
|
|
vm_page_protect(p, VM_PROT_NONE);
|
|
/*
|
|
* else if on the next go-around we
|
|
* will deactivate the page we need to
|
|
* place the page on the end of the
|
|
* queue to age the other pages in
|
|
* memory.
|
|
*/
|
|
} else {
|
|
TAILQ_REMOVE(&vm_page_queue_active, p, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, p, pageq);
|
|
}
|
|
/*
|
|
* see if we are done yet
|
|
*/
|
|
if (p->flags & PG_INACTIVE) {
|
|
--count;
|
|
++dcount;
|
|
if (count <= 0 &&
|
|
cnt.v_inactive_count > cnt.v_inactive_target) {
|
|
return dcount;
|
|
}
|
|
}
|
|
} else {
|
|
/*
|
|
* Move the page to the bottom of the queue.
|
|
*/
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(p));
|
|
p->flags &= ~PG_REFERENCED;
|
|
if (p->act_count < ACT_MAX)
|
|
p->act_count += ACT_ADVANCE;
|
|
|
|
TAILQ_REMOVE(&vm_page_queue_active, p, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, p, pageq);
|
|
}
|
|
} else if ((p->flags & (PG_INACTIVE | PG_BUSY)) == PG_INACTIVE) {
|
|
vm_page_protect(p, VM_PROT_NONE);
|
|
}
|
|
p = next;
|
|
}
|
|
return dcount;
|
|
}
|
|
|
|
|
|
/*
|
|
* deactivate some number of pages in a map, try to do it fairly, but
|
|
* that is really hard to do.
|
|
*/
|
|
|
|
static void
|
|
vm_pageout_map_deactivate_pages(map, entry, count, freeer)
|
|
vm_map_t map;
|
|
vm_map_entry_t entry;
|
|
int *count;
|
|
freeer_fcn_t *freeer;
|
|
{
|
|
vm_map_t tmpm;
|
|
vm_map_entry_t tmpe;
|
|
vm_object_t obj;
|
|
|
|
if (*count <= 0)
|
|
return;
|
|
vm_map_reference(map);
|
|
if (!lock_try_read(&map->lock)) {
|
|
vm_map_deallocate(map);
|
|
return;
|
|
}
|
|
if (entry == 0) {
|
|
tmpe = map->header.next;
|
|
while (tmpe != &map->header && *count > 0) {
|
|
vm_pageout_map_deactivate_pages(map, tmpe, count, freeer);
|
|
tmpe = tmpe->next;
|
|
};
|
|
} else if (entry->is_sub_map || entry->is_a_map) {
|
|
tmpm = entry->object.share_map;
|
|
tmpe = tmpm->header.next;
|
|
while (tmpe != &tmpm->header && *count > 0) {
|
|
vm_pageout_map_deactivate_pages(tmpm, tmpe, count, freeer);
|
|
tmpe = tmpe->next;
|
|
};
|
|
} else if ((obj = entry->object.vm_object) != 0) {
|
|
*count -= (*freeer) (map, obj, *count, TRUE);
|
|
}
|
|
lock_read_done(&map->lock);
|
|
vm_map_deallocate(map);
|
|
return;
|
|
}
|
|
|
|
static void
|
|
vm_req_vmdaemon()
|
|
{
|
|
static int lastrun = 0;
|
|
|
|
if ((ticks > (lastrun + hz / 10)) || (ticks < lastrun)) {
|
|
wakeup(&vm_daemon_needed);
|
|
lastrun = ticks;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_pageout_scan does the dirty work for the pageout daemon.
|
|
*/
|
|
static int
|
|
vm_pageout_scan()
|
|
{
|
|
vm_page_t m;
|
|
int page_shortage, maxscan, maxlaunder, pcount;
|
|
int pages_freed;
|
|
vm_page_t next;
|
|
struct proc *p, *bigproc;
|
|
vm_offset_t size, bigsize;
|
|
vm_object_t object;
|
|
int force_wakeup = 0;
|
|
int vnodes_skipped = 0;
|
|
|
|
pages_freed = 0;
|
|
|
|
/*
|
|
* Start scanning the inactive queue for pages we can free. We keep
|
|
* scanning until we have enough free pages or we have scanned through
|
|
* the entire queue. If we encounter dirty pages, we start cleaning
|
|
* them.
|
|
*/
|
|
|
|
maxlaunder = (cnt.v_inactive_target > MAXLAUNDER) ?
|
|
MAXLAUNDER : cnt.v_inactive_target;
|
|
|
|
rescan1:
|
|
maxscan = cnt.v_inactive_count;
|
|
m = vm_page_queue_inactive.tqh_first;
|
|
while ((m != NULL) && (maxscan-- > 0) &&
|
|
((cnt.v_cache_count + cnt.v_free_count) < (cnt.v_cache_min + cnt.v_free_target))) {
|
|
vm_page_t next;
|
|
|
|
cnt.v_pdpages++;
|
|
next = m->pageq.tqe_next;
|
|
|
|
#if defined(VM_DIAGNOSE)
|
|
if ((m->flags & PG_INACTIVE) == 0) {
|
|
printf("vm_pageout_scan: page not inactive?\n");
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* dont mess with busy pages
|
|
*/
|
|
if (m->hold_count || m->busy || (m->flags & PG_BUSY)) {
|
|
TAILQ_REMOVE(&vm_page_queue_inactive, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
|
|
m = next;
|
|
continue;
|
|
}
|
|
if (((m->flags & PG_REFERENCED) == 0) &&
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(m))) {
|
|
m->flags |= PG_REFERENCED;
|
|
}
|
|
if (m->object->ref_count == 0) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
}
|
|
if ((m->flags & (PG_REFERENCED|PG_WANTED)) != 0) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
vm_page_activate(m);
|
|
if (m->act_count < ACT_MAX)
|
|
m->act_count += ACT_ADVANCE;
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
vm_page_test_dirty(m);
|
|
if (m->dirty == 0) {
|
|
if (m->bmapped == 0) {
|
|
if (m->valid == 0) {
|
|
pmap_page_protect(VM_PAGE_TO_PHYS(m), VM_PROT_NONE);
|
|
vm_page_free(m);
|
|
cnt.v_dfree++;
|
|
} else {
|
|
vm_page_cache(m);
|
|
}
|
|
++pages_freed;
|
|
} else {
|
|
m = next;
|
|
continue;
|
|
}
|
|
} else if (maxlaunder > 0) {
|
|
int written;
|
|
struct vnode *vp = NULL;
|
|
|
|
object = m->object;
|
|
if (object->flags & OBJ_DEAD) {
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
if (object->type == OBJT_VNODE) {
|
|
vp = object->handle;
|
|
if (VOP_ISLOCKED(vp) || vget(vp, 1)) {
|
|
if (object->flags & OBJ_MIGHTBEDIRTY)
|
|
++vnodes_skipped;
|
|
m = next;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If a page is dirty, then it is either being washed
|
|
* (but not yet cleaned) or it is still in the
|
|
* laundry. If it is still in the laundry, then we
|
|
* start the cleaning operation.
|
|
*/
|
|
written = vm_pageout_clean(m, 0);
|
|
|
|
if (vp)
|
|
vput(vp);
|
|
|
|
if (!next) {
|
|
break;
|
|
}
|
|
maxlaunder -= written;
|
|
/*
|
|
* if the next page has been re-activated, start
|
|
* scanning again
|
|
*/
|
|
if ((next->flags & PG_INACTIVE) == 0) {
|
|
vm_pager_sync();
|
|
goto rescan1;
|
|
}
|
|
}
|
|
m = next;
|
|
}
|
|
|
|
/*
|
|
* Compute the page shortage. If we are still very low on memory be
|
|
* sure that we will move a minimal amount of pages from active to
|
|
* inactive.
|
|
*/
|
|
|
|
page_shortage = cnt.v_inactive_target -
|
|
(cnt.v_free_count + cnt.v_inactive_count + cnt.v_cache_count);
|
|
if (page_shortage <= 0) {
|
|
if (pages_freed == 0) {
|
|
page_shortage = cnt.v_free_min - cnt.v_free_count;
|
|
} else {
|
|
page_shortage = 1;
|
|
}
|
|
}
|
|
maxscan = MAXSCAN;
|
|
pcount = cnt.v_active_count;
|
|
m = vm_page_queue_active.tqh_first;
|
|
while ((m != NULL) && (maxscan > 0) && (pcount-- > 0) && (page_shortage > 0)) {
|
|
|
|
cnt.v_pdpages++;
|
|
next = m->pageq.tqe_next;
|
|
|
|
/*
|
|
* Don't deactivate pages that are busy.
|
|
*/
|
|
if ((m->busy != 0) ||
|
|
(m->flags & PG_BUSY) ||
|
|
(m->hold_count != 0)) {
|
|
TAILQ_REMOVE(&vm_page_queue_active, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
m = next;
|
|
/* printf("busy: s: %d, f: 0x%x, h: %d\n",
|
|
m->busy, m->flags, m->hold_count); */
|
|
continue;
|
|
}
|
|
if (m->object->ref_count &&
|
|
((m->flags & (PG_REFERENCED|PG_WANTED)) ||
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(m)))) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
m->flags &= ~PG_REFERENCED;
|
|
if (m->act_count < ACT_MAX) {
|
|
m->act_count += ACT_ADVANCE;
|
|
}
|
|
TAILQ_REMOVE(&vm_page_queue_active, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
} else {
|
|
m->flags &= ~PG_REFERENCED;
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
m->act_count -= min(m->act_count, ACT_DECLINE);
|
|
|
|
/*
|
|
* if the page act_count is zero -- then we deactivate
|
|
*/
|
|
if (!m->act_count && (page_shortage > 0)) {
|
|
if (m->object->ref_count == 0) {
|
|
--page_shortage;
|
|
vm_page_test_dirty(m);
|
|
if ((m->bmapped == 0) && (m->dirty == 0) ) {
|
|
m->act_count = 0;
|
|
vm_page_cache(m);
|
|
} else {
|
|
vm_page_deactivate(m);
|
|
}
|
|
} else {
|
|
vm_page_deactivate(m);
|
|
--page_shortage;
|
|
}
|
|
} else if (m->act_count) {
|
|
TAILQ_REMOVE(&vm_page_queue_active, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
}
|
|
}
|
|
maxscan--;
|
|
m = next;
|
|
}
|
|
|
|
/*
|
|
* We try to maintain some *really* free pages, this allows interrupt
|
|
* code to be guaranteed space.
|
|
*/
|
|
while (cnt.v_free_count < cnt.v_free_reserved) {
|
|
m = vm_page_queue_cache.tqh_first;
|
|
if (!m)
|
|
break;
|
|
vm_page_free(m);
|
|
cnt.v_dfree++;
|
|
}
|
|
|
|
/*
|
|
* If we didn't get enough free pages, and we have skipped a vnode
|
|
* in a writeable object, wakeup the sync daemon. And kick swapout
|
|
* if we did not get enough free pages.
|
|
*/
|
|
if ((cnt.v_cache_count + cnt.v_free_count) < cnt.v_free_target) {
|
|
if (vnodes_skipped &&
|
|
(cnt.v_cache_count + cnt.v_free_count) < cnt.v_free_min) {
|
|
if (!vfs_update_wakeup) {
|
|
vfs_update_wakeup = 1;
|
|
wakeup(&vfs_update_wakeup);
|
|
}
|
|
}
|
|
/*
|
|
* now swap processes out if we are in low memory conditions
|
|
*/
|
|
if (!swap_pager_full && vm_swap_size &&
|
|
vm_pageout_req_swapout == 0) {
|
|
vm_pageout_req_swapout = 1;
|
|
vm_req_vmdaemon();
|
|
}
|
|
}
|
|
|
|
if ((cnt.v_inactive_count + cnt.v_free_count + cnt.v_cache_count) <
|
|
(cnt.v_inactive_target + cnt.v_free_min)) {
|
|
vm_req_vmdaemon();
|
|
}
|
|
|
|
/*
|
|
* make sure that we have swap space -- if we are low on memory and
|
|
* swap -- then kill the biggest process.
|
|
*/
|
|
if ((vm_swap_size == 0 || swap_pager_full) &&
|
|
((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min)) {
|
|
bigproc = NULL;
|
|
bigsize = 0;
|
|
for (p = (struct proc *) allproc; p != NULL; p = p->p_next) {
|
|
/*
|
|
* if this is a system process, skip it
|
|
*/
|
|
if ((p->p_flag & P_SYSTEM) || (p->p_pid == 1) ||
|
|
((p->p_pid < 48) && (vm_swap_size != 0))) {
|
|
continue;
|
|
}
|
|
/*
|
|
* if the process is in a non-running type state,
|
|
* don't touch it.
|
|
*/
|
|
if (p->p_stat != SRUN && p->p_stat != SSLEEP) {
|
|
continue;
|
|
}
|
|
/*
|
|
* get the process size
|
|
*/
|
|
size = p->p_vmspace->vm_pmap.pm_stats.resident_count;
|
|
/*
|
|
* if the this process is bigger than the biggest one
|
|
* remember it.
|
|
*/
|
|
if (size > bigsize) {
|
|
bigproc = p;
|
|
bigsize = size;
|
|
}
|
|
}
|
|
if (bigproc != NULL) {
|
|
printf("Process %lu killed by vm_pageout -- out of swap\n", (u_long) bigproc->p_pid);
|
|
psignal(bigproc, SIGKILL);
|
|
bigproc->p_estcpu = 0;
|
|
bigproc->p_nice = PRIO_MIN;
|
|
resetpriority(bigproc);
|
|
wakeup(&cnt.v_free_count);
|
|
}
|
|
}
|
|
return force_wakeup;
|
|
}
|
|
|
|
/*
|
|
* vm_pageout is the high level pageout daemon.
|
|
*/
|
|
static void
|
|
vm_pageout()
|
|
{
|
|
(void) spl0();
|
|
|
|
/*
|
|
* Initialize some paging parameters.
|
|
*/
|
|
|
|
cnt.v_interrupt_free_min = 2;
|
|
|
|
if (cnt.v_page_count > 1024)
|
|
cnt.v_free_min = 4 + (cnt.v_page_count - 1024) / 200;
|
|
else
|
|
cnt.v_free_min = 4;
|
|
/*
|
|
* free_reserved needs to include enough for the largest swap pager
|
|
* structures plus enough for any pv_entry structs when paging.
|
|
*/
|
|
cnt.v_pageout_free_min = 6 + cnt.v_page_count / 1024 +
|
|
cnt.v_interrupt_free_min;
|
|
cnt.v_free_reserved = cnt.v_pageout_free_min + 6;
|
|
cnt.v_free_target = 3 * cnt.v_free_min + cnt.v_free_reserved;
|
|
cnt.v_free_min += cnt.v_free_reserved;
|
|
|
|
if (cnt.v_page_count > 1024) {
|
|
cnt.v_cache_max = (cnt.v_free_count - 1024) / 2;
|
|
cnt.v_cache_min = (cnt.v_free_count - 1024) / 8;
|
|
cnt.v_inactive_target = 2*cnt.v_cache_min + 192;
|
|
} else {
|
|
cnt.v_cache_min = 0;
|
|
cnt.v_cache_max = 0;
|
|
cnt.v_inactive_target = cnt.v_free_count / 4;
|
|
}
|
|
|
|
/* XXX does not really belong here */
|
|
if (vm_page_max_wired == 0)
|
|
vm_page_max_wired = cnt.v_free_count / 3;
|
|
|
|
|
|
swap_pager_swap_init();
|
|
/*
|
|
* The pageout daemon is never done, so loop forever.
|
|
*/
|
|
while (TRUE) {
|
|
int s = splhigh();
|
|
|
|
if (!vm_pages_needed ||
|
|
((cnt.v_free_count >= cnt.v_free_reserved) &&
|
|
(cnt.v_free_count + cnt.v_cache_count >= cnt.v_free_min))) {
|
|
vm_pages_needed = 0;
|
|
tsleep(&vm_pages_needed, PVM, "psleep", 0);
|
|
}
|
|
vm_pages_needed = 0;
|
|
splx(s);
|
|
cnt.v_pdwakeups++;
|
|
vm_pager_sync();
|
|
vm_pageout_scan();
|
|
vm_pager_sync();
|
|
wakeup(&cnt.v_free_count);
|
|
wakeup(kmem_map);
|
|
}
|
|
}
|
|
|
|
static void
|
|
vm_daemon()
|
|
{
|
|
vm_object_t object;
|
|
struct proc *p;
|
|
|
|
while (TRUE) {
|
|
tsleep(&vm_daemon_needed, PUSER, "psleep", 0);
|
|
if (vm_pageout_req_swapout) {
|
|
swapout_procs();
|
|
vm_pageout_req_swapout = 0;
|
|
}
|
|
/*
|
|
* scan the processes for exceeding their rlimits or if
|
|
* process is swapped out -- deactivate pages
|
|
*/
|
|
|
|
for (p = (struct proc *) allproc; p != NULL; p = p->p_next) {
|
|
int overage;
|
|
quad_t limit;
|
|
vm_offset_t size;
|
|
|
|
/*
|
|
* if this is a system process or if we have already
|
|
* looked at this process, skip it.
|
|
*/
|
|
if (p->p_flag & (P_SYSTEM | P_WEXIT)) {
|
|
continue;
|
|
}
|
|
/*
|
|
* if the process is in a non-running type state,
|
|
* don't touch it.
|
|
*/
|
|
if (p->p_stat != SRUN && p->p_stat != SSLEEP) {
|
|
continue;
|
|
}
|
|
/*
|
|
* get a limit
|
|
*/
|
|
limit = qmin(p->p_rlimit[RLIMIT_RSS].rlim_cur,
|
|
p->p_rlimit[RLIMIT_RSS].rlim_max);
|
|
|
|
/*
|
|
* let processes that are swapped out really be
|
|
* swapped out set the limit to nothing (will force a
|
|
* swap-out.)
|
|
*/
|
|
if ((p->p_flag & P_INMEM) == 0)
|
|
limit = 0; /* XXX */
|
|
|
|
size = p->p_vmspace->vm_pmap.pm_stats.resident_count * PAGE_SIZE;
|
|
if (limit >= 0 && size >= limit) {
|
|
overage = (size - limit) >> PAGE_SHIFT;
|
|
vm_pageout_map_deactivate_pages(&p->p_vmspace->vm_map,
|
|
(vm_map_entry_t) 0, &overage, vm_pageout_object_deactivate_pages);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* we remove cached objects that have no RSS...
|
|
*/
|
|
restart:
|
|
object = vm_object_cached_list.tqh_first;
|
|
while (object) {
|
|
/*
|
|
* if there are no resident pages -- get rid of the object
|
|
*/
|
|
if (object->resident_page_count == 0) {
|
|
vm_object_reference(object);
|
|
pager_cache(object, FALSE);
|
|
goto restart;
|
|
}
|
|
object = object->cached_list.tqe_next;
|
|
}
|
|
}
|
|
}
|