904 lines
23 KiB
C
904 lines
23 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 1.21 1994/10/23 20:53:33 davidg Exp $
|
|
*/
|
|
|
|
/*
|
|
* The proverbial page-out daemon.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/malloc.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_page.h>
|
|
#include <vm/vm_pageout.h>
|
|
#include <vm/swap_pager.h>
|
|
|
|
extern vm_map_t kmem_map;
|
|
int vm_pages_needed; /* Event on which pageout daemon sleeps */
|
|
int vm_pagescanner; /* Event on which pagescanner sleeps */
|
|
int vm_pageout_free_min = 0; /* Stop pageout to wait for pagers at this free level */
|
|
|
|
int vm_pageout_pages_needed = 0; /* flag saying that the pageout daemon needs pages */
|
|
int vm_page_pagesfreed;
|
|
int vm_desired_cache_size;
|
|
|
|
extern int npendingio;
|
|
extern int hz;
|
|
int vm_pageout_proc_limit;
|
|
extern int nswiodone;
|
|
extern int swap_pager_full;
|
|
extern int vm_swap_size;
|
|
extern int swap_pager_ready();
|
|
|
|
#define MAXREF 32767
|
|
|
|
#define MAXSCAN 512 /* maximum number of pages to scan in active queue */
|
|
/* set the "clock" hands to be (MAXSCAN * 4096) Bytes */
|
|
#define ACT_DECLINE 1
|
|
#define ACT_ADVANCE 3
|
|
#define ACT_MAX 100
|
|
|
|
#define LOWATER ((2048*1024)/NBPG)
|
|
|
|
#define VM_PAGEOUT_PAGE_COUNT 8
|
|
int vm_pageout_page_count = VM_PAGEOUT_PAGE_COUNT;
|
|
int vm_pageout_req_do_stats;
|
|
|
|
int vm_page_max_wired = 0; /* XXX max # of wired pages system-wide */
|
|
|
|
|
|
/*
|
|
* vm_pageout_clean:
|
|
* cleans a vm_page
|
|
*/
|
|
int
|
|
vm_pageout_clean(m, sync)
|
|
register vm_page_t m;
|
|
int sync;
|
|
{
|
|
/*
|
|
* 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!)
|
|
*/
|
|
|
|
register vm_object_t object;
|
|
register vm_pager_t pager;
|
|
int pageout_status[VM_PAGEOUT_PAGE_COUNT];
|
|
vm_page_t ms[VM_PAGEOUT_PAGE_COUNT];
|
|
int pageout_count;
|
|
int anyok=0;
|
|
int i;
|
|
vm_offset_t offset = m->offset;
|
|
|
|
object = m->object;
|
|
if (!object) {
|
|
printf("pager: object missing\n");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Try to collapse the object before
|
|
* making a pager for it. We must
|
|
* unlock the page queues first.
|
|
* We try to defer the creation of a pager
|
|
* until all shadows are not paging. This
|
|
* allows vm_object_collapse to work better and
|
|
* helps control swap space size.
|
|
* (J. Dyson 11 Nov 93)
|
|
*/
|
|
|
|
if (!object->pager &&
|
|
cnt.v_free_count < vm_pageout_free_min)
|
|
return 0;
|
|
|
|
if (!object->pager &&
|
|
object->shadow &&
|
|
object->shadow->paging_in_progress)
|
|
return 0;
|
|
|
|
if( !sync) {
|
|
if (object->shadow) {
|
|
vm_object_collapse(object);
|
|
if (!vm_page_lookup(object, offset))
|
|
return 0;
|
|
}
|
|
|
|
if ((m->busy != 0) ||
|
|
(m->flags & PG_BUSY) || (m->hold_count != 0)) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
pageout_count = 1;
|
|
ms[0] = m;
|
|
|
|
pager = object->pager;
|
|
if (pager) {
|
|
for (i = 1; i < vm_pageout_page_count; i++) {
|
|
ms[i] = vm_page_lookup(object, offset+i*NBPG);
|
|
if (ms[i]) {
|
|
if (( ((ms[i]->flags & (PG_CLEAN|PG_INACTIVE|PG_BUSY)) == PG_INACTIVE)
|
|
|| ( (ms[i]->flags & (PG_CLEAN|PG_BUSY)) == 0 && sync == VM_PAGEOUT_FORCE))
|
|
&& (ms[i]->wire_count == 0)
|
|
&& (ms[i]->busy == 0)
|
|
&& (ms[i]->hold_count == 0))
|
|
pageout_count++;
|
|
else
|
|
break;
|
|
} else
|
|
break;
|
|
}
|
|
for(i=0;i<pageout_count;i++) {
|
|
ms[i]->flags |= PG_BUSY;
|
|
pmap_page_protect(VM_PAGE_TO_PHYS(ms[i]), VM_PROT_READ);
|
|
}
|
|
object->paging_in_progress += pageout_count;
|
|
} else {
|
|
|
|
m->flags |= PG_BUSY;
|
|
|
|
pmap_page_protect(VM_PAGE_TO_PHYS(m), VM_PROT_READ);
|
|
|
|
object->paging_in_progress++;
|
|
|
|
pager = vm_pager_allocate(PG_DFLT, (caddr_t)0,
|
|
object->size, VM_PROT_ALL, 0);
|
|
if (pager != NULL) {
|
|
vm_object_setpager(object, pager, 0, FALSE);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there is no pager for the page,
|
|
* use the default pager. If there's
|
|
* no place to put the page at the
|
|
* moment, leave it in the laundry and
|
|
* hope that there will be paging space
|
|
* later.
|
|
*/
|
|
|
|
if ((pager && pager->pg_type == PG_SWAP) ||
|
|
cnt.v_free_count >= vm_pageout_free_min) {
|
|
if( pageout_count == 1) {
|
|
pageout_status[0] = pager ?
|
|
vm_pager_put(pager, m,
|
|
((sync || (object == kernel_object)) ? TRUE: FALSE)) :
|
|
VM_PAGER_FAIL;
|
|
} else {
|
|
if( !pager) {
|
|
for(i=0;i<pageout_count;i++)
|
|
pageout_status[i] = VM_PAGER_FAIL;
|
|
} else {
|
|
vm_pager_put_pages(pager, ms, pageout_count,
|
|
((sync || (object == kernel_object)) ? TRUE : FALSE),
|
|
pageout_status);
|
|
}
|
|
}
|
|
|
|
} else {
|
|
for(i=0;i<pageout_count;i++)
|
|
pageout_status[i] = VM_PAGER_FAIL;
|
|
}
|
|
|
|
for(i=0;i<pageout_count;i++) {
|
|
switch (pageout_status[i]) {
|
|
case VM_PAGER_OK:
|
|
ms[i]->flags &= ~PG_LAUNDRY;
|
|
++anyok;
|
|
break;
|
|
case VM_PAGER_PEND:
|
|
ms[i]->flags &= ~PG_LAUNDRY;
|
|
++anyok;
|
|
break;
|
|
case VM_PAGER_BAD:
|
|
/*
|
|
* Page outside of range of object.
|
|
* Right now we essentially lose the
|
|
* changes by pretending it worked.
|
|
*/
|
|
ms[i]->flags &= ~PG_LAUNDRY;
|
|
ms[i]->flags |= PG_CLEAN;
|
|
pmap_clear_modify(VM_PAGE_TO_PHYS(ms[i]));
|
|
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 (ms[i]->flags & PG_INACTIVE)
|
|
vm_page_activate(ms[i]);
|
|
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) {
|
|
PAGE_WAKEUP(ms[i]);
|
|
if (--object->paging_in_progress == 0)
|
|
wakeup((caddr_t) object);
|
|
if ((ms[i]->flags & PG_REFERENCED) ||
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(ms[i]))) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(ms[i]));
|
|
ms[i]->flags &= ~PG_REFERENCED;
|
|
if( ms[i]->flags & PG_INACTIVE)
|
|
vm_page_activate(ms[i]);
|
|
}
|
|
}
|
|
}
|
|
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
|
|
* shadows.
|
|
*
|
|
* The object and map must be locked.
|
|
*/
|
|
int
|
|
vm_pageout_object_deactivate_pages(map, object, count)
|
|
vm_map_t map;
|
|
vm_object_t object;
|
|
int count;
|
|
{
|
|
register vm_page_t p, next;
|
|
int rcount;
|
|
int dcount;
|
|
|
|
dcount = 0;
|
|
if (count == 0)
|
|
count = 1;
|
|
|
|
if (object->shadow) {
|
|
int scount = count;
|
|
if( object->shadow->ref_count > 1)
|
|
scount /= object->shadow->ref_count;
|
|
if( scount)
|
|
dcount += vm_pageout_object_deactivate_pages(map, object->shadow, scount);
|
|
}
|
|
|
|
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++;
|
|
vm_page_lock_queues();
|
|
/*
|
|
* 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 &&
|
|
p->wire_count == 0 &&
|
|
p->hold_count == 0 &&
|
|
p->busy == 0 &&
|
|
pmap_page_exists(vm_map_pmap(map), VM_PAGE_TO_PHYS(p))) {
|
|
if (!pmap_is_referenced(VM_PAGE_TO_PHYS(p)) &&
|
|
(p->flags & PG_REFERENCED) == 0) {
|
|
p->act_count -= min(p->act_count, ACT_DECLINE);
|
|
/*
|
|
* if the page act_count is zero -- then we deactivate
|
|
*/
|
|
if (!p->act_count) {
|
|
vm_page_deactivate(p);
|
|
pmap_page_protect(VM_PAGE_TO_PHYS(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);
|
|
TAILQ_REMOVE(&object->memq, p, listq);
|
|
TAILQ_INSERT_TAIL(&object->memq, p, listq);
|
|
}
|
|
/*
|
|
* see if we are done yet
|
|
*/
|
|
if (p->flags & PG_INACTIVE) {
|
|
--count;
|
|
++dcount;
|
|
if (count <= 0 &&
|
|
cnt.v_inactive_count > cnt.v_inactive_target) {
|
|
vm_page_unlock_queues();
|
|
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);
|
|
TAILQ_REMOVE(&object->memq, p, listq);
|
|
TAILQ_INSERT_TAIL(&object->memq, p, listq);
|
|
}
|
|
}
|
|
|
|
vm_page_unlock_queues();
|
|
p = next;
|
|
}
|
|
return dcount;
|
|
}
|
|
|
|
|
|
/*
|
|
* deactivate some number of pages in a map, try to do it fairly, but
|
|
* that is really hard to do.
|
|
*/
|
|
|
|
void
|
|
vm_pageout_map_deactivate_pages(map, entry, count, freeer)
|
|
vm_map_t map;
|
|
vm_map_entry_t entry;
|
|
int *count;
|
|
int (*freeer)(vm_map_t, vm_object_t, int);
|
|
{
|
|
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);
|
|
}
|
|
lock_read_done(&map->lock);
|
|
vm_map_deallocate(map);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* vm_pageout_scan does the dirty work for the pageout daemon.
|
|
*/
|
|
int
|
|
vm_pageout_scan()
|
|
{
|
|
vm_page_t m;
|
|
int page_shortage, maxscan, maxlaunder;
|
|
int pages_freed;
|
|
int desired_free;
|
|
vm_page_t next;
|
|
struct proc *p, *bigproc;
|
|
vm_offset_t size, bigsize;
|
|
vm_object_t object;
|
|
int force_wakeup = 0;
|
|
int cache_size, orig_cache_size;
|
|
|
|
/*
|
|
* We manage the cached memory by attempting to keep it
|
|
* at about the desired level.
|
|
* We deactivate the pages for the oldest cached objects
|
|
* first. This keeps pages that are "cached" from hogging
|
|
* physical memory.
|
|
*/
|
|
orig_cache_size = 0;
|
|
object = vm_object_cached_list.tqh_first;
|
|
|
|
/* calculate the total cached size */
|
|
|
|
while( object) {
|
|
orig_cache_size += object->resident_page_count;
|
|
object = object->cached_list.tqe_next;
|
|
}
|
|
|
|
redeact:
|
|
cache_size = orig_cache_size;
|
|
object = vm_object_cached_list.tqh_first;
|
|
vm_object_cache_lock();
|
|
while ( object && (cnt.v_inactive_count < cnt.v_inactive_target)) {
|
|
vm_object_cache_unlock();
|
|
/*
|
|
* if there are no resident pages -- get rid of the object
|
|
*/
|
|
if( object->resident_page_count == 0) {
|
|
if (object != vm_object_lookup(object->pager))
|
|
panic("vm_pageout_scan: I'm sooo confused.");
|
|
pager_cache(object, FALSE);
|
|
goto redeact;
|
|
} else if( cache_size >= (vm_swap_size?vm_desired_cache_size:0)) {
|
|
/*
|
|
* if there are resident pages -- deactivate them
|
|
*/
|
|
vm_object_deactivate_pages(object);
|
|
cache_size -= object->resident_page_count;
|
|
}
|
|
object = object->cached_list.tqe_next;
|
|
|
|
vm_object_cache_lock();
|
|
}
|
|
vm_object_cache_unlock();
|
|
|
|
morefree:
|
|
/*
|
|
* now swap processes out if we are in low memory conditions
|
|
*/
|
|
if ((cnt.v_free_count <= cnt.v_free_min) && !swap_pager_full && vm_swap_size) {
|
|
/*
|
|
* swap out inactive processes
|
|
*/
|
|
swapout_threads();
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
size = p->p_vmspace->vm_pmap.pm_stats.resident_count * NBPG;
|
|
if (limit >= 0 && size >= limit) {
|
|
overage = (size - limit) / NBPG;
|
|
vm_pageout_map_deactivate_pages(&p->p_vmspace->vm_map,
|
|
(vm_map_entry_t) 0, &overage, vm_pageout_object_deactivate_pages);
|
|
}
|
|
}
|
|
|
|
if (((cnt.v_free_count + cnt.v_inactive_count) >=
|
|
(cnt.v_inactive_target + cnt.v_free_target)) &&
|
|
(cnt.v_free_count >= cnt.v_free_target))
|
|
return force_wakeup;
|
|
|
|
pages_freed = 0;
|
|
desired_free = cnt.v_free_target;
|
|
|
|
/*
|
|
* 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_free_target - cnt.v_free_count);
|
|
maxscan = cnt.v_inactive_count;
|
|
rescan1:
|
|
m = vm_page_queue_inactive.tqh_first;
|
|
while (m && (maxscan-- > 0) &&
|
|
(cnt.v_free_count < desired_free) ) {
|
|
vm_page_t next;
|
|
|
|
cnt.v_pdpages++;
|
|
next = m->pageq.tqe_next;
|
|
|
|
if( (m->flags & PG_INACTIVE) == 0) {
|
|
printf("vm_pageout_scan: page not inactive?");
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* activate held pages
|
|
*/
|
|
if (m->hold_count != 0) {
|
|
vm_page_activate(m);
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* dont mess with busy pages
|
|
*/
|
|
if (m->busy || (m->flags & PG_BUSY)) {
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* NOTE: PG_CLEAN doesn't guarantee that the page is clean.
|
|
*/
|
|
if (m->flags & PG_CLEAN) {
|
|
/*
|
|
* If we're not low on memory and the page has been reference,
|
|
* or if the page has been modified, then reactivate the page.
|
|
*/
|
|
if (((cnt.v_free_count > vm_pageout_free_min) &&
|
|
(pmap_is_referenced(VM_PAGE_TO_PHYS(m)) || ((m->flags & PG_REFERENCED) != 0))) ||
|
|
pmap_is_modified(VM_PAGE_TO_PHYS(m))) {
|
|
m->flags &= ~PG_REFERENCED;
|
|
vm_page_activate(m);
|
|
} else if (!m->act_count) {
|
|
pmap_page_protect(VM_PAGE_TO_PHYS(m),
|
|
VM_PROT_NONE);
|
|
vm_page_free(m);
|
|
++cnt.v_dfree;
|
|
++pages_freed;
|
|
} else {
|
|
m->act_count -= min(m->act_count, ACT_DECLINE);
|
|
TAILQ_REMOVE(&vm_page_queue_inactive, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
|
|
}
|
|
} else if ((m->flags & PG_LAUNDRY) && maxlaunder > 0) {
|
|
int written;
|
|
if (pmap_is_referenced(VM_PAGE_TO_PHYS(m)) ||
|
|
((m->flags & PG_REFERENCED) != 0)) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
vm_page_activate(m);
|
|
m->flags &= ~PG_REFERENCED;
|
|
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 (written)
|
|
maxlaunder -= written;
|
|
|
|
if (!next)
|
|
break;
|
|
/*
|
|
* if the next page has been re-activated, start scanning again
|
|
*/
|
|
if ((next->flags & PG_INACTIVE) == 0)
|
|
goto rescan1;
|
|
} else if ((m->flags & PG_REFERENCED) ||
|
|
pmap_is_referenced(VM_PAGE_TO_PHYS(m))) {
|
|
pmap_clear_reference(VM_PAGE_TO_PHYS(m));
|
|
m->flags &= ~PG_REFERENCED;
|
|
vm_page_activate(m);
|
|
}
|
|
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);
|
|
|
|
if (page_shortage <= 0) {
|
|
if (pages_freed == 0) {
|
|
if( cnt.v_free_count < cnt.v_free_min) {
|
|
page_shortage = cnt.v_free_min - cnt.v_free_count + 1;
|
|
} else if(((cnt.v_free_count + cnt.v_inactive_count) <
|
|
(cnt.v_free_min + cnt.v_inactive_target))) {
|
|
page_shortage = 1;
|
|
} else {
|
|
page_shortage = 0;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
maxscan = cnt.v_active_count;
|
|
m = vm_page_queue_active.tqh_first;
|
|
while (m && maxscan-- && (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)) {
|
|
m = next;
|
|
continue;
|
|
}
|
|
|
|
if ((m->flags & PG_REFERENCED) ||
|
|
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);
|
|
TAILQ_REMOVE(&m->object->memq, m, listq);
|
|
TAILQ_INSERT_TAIL(&m->object->memq, m, listq);
|
|
} else {
|
|
m->act_count -= min(m->act_count, ACT_DECLINE);
|
|
|
|
/*
|
|
* if the page act_count is zero -- then we deactivate
|
|
*/
|
|
if (!m->act_count) {
|
|
vm_page_deactivate(m);
|
|
--page_shortage;
|
|
/*
|
|
* 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, m, pageq);
|
|
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
|
|
TAILQ_REMOVE(&m->object->memq, m, listq);
|
|
TAILQ_INSERT_TAIL(&m->object->memq, m, listq);
|
|
}
|
|
}
|
|
m = next;
|
|
}
|
|
|
|
/*
|
|
* if we have not freed any pages and we are desparate for memory
|
|
* then we keep trying until we get some (any) memory.
|
|
*/
|
|
|
|
if (!force_wakeup && (swap_pager_full || !force_wakeup ||
|
|
(pages_freed == 0 && (cnt.v_free_count < cnt.v_free_min)))){
|
|
vm_pager_sync();
|
|
force_wakeup = 1;
|
|
goto morefree;
|
|
}
|
|
|
|
/*
|
|
* 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_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 < 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( (caddr_t) &cnt.v_free_count);
|
|
}
|
|
}
|
|
vm_page_pagesfreed += pages_freed;
|
|
return force_wakeup;
|
|
}
|
|
|
|
/*
|
|
* vm_pageout is the high level pageout daemon.
|
|
*/
|
|
void
|
|
vm_pageout()
|
|
{
|
|
(void) spl0();
|
|
|
|
/*
|
|
* Initialize some paging parameters.
|
|
*/
|
|
|
|
cnt.v_free_min = 12;
|
|
/*
|
|
* free_reserved needs to include enough for the largest
|
|
* swap pager structures plus enough for any pv_entry
|
|
* structs when paging.
|
|
*/
|
|
vm_pageout_free_min = 4 + cnt.v_page_count / 1024;
|
|
cnt.v_free_reserved = vm_pageout_free_min + 2;
|
|
if (cnt.v_free_min < 8)
|
|
cnt.v_free_min = 8;
|
|
if (cnt.v_free_min > 32)
|
|
cnt.v_free_min = 32;
|
|
cnt.v_free_target = 2*cnt.v_free_min + cnt.v_free_reserved;
|
|
cnt.v_inactive_target = cnt.v_free_count / 12;
|
|
cnt.v_free_min += cnt.v_free_reserved;
|
|
vm_desired_cache_size = cnt.v_page_count / 3;
|
|
|
|
/* XXX does not really belong here */
|
|
if (vm_page_max_wired == 0)
|
|
vm_page_max_wired = cnt.v_free_count / 3;
|
|
|
|
|
|
(void) swap_pager_alloc(0, 0, 0, 0);
|
|
|
|
/*
|
|
* The pageout daemon is never done, so loop
|
|
* forever.
|
|
*/
|
|
while (TRUE) {
|
|
int force_wakeup;
|
|
/*
|
|
cnt.v_free_min = 12 + averunnable.ldavg[0] / 1024;
|
|
cnt.v_free_target = 2*cnt.v_free_min + cnt.v_free_reserved;
|
|
cnt.v_inactive_target = cnt.v_free_target*2;
|
|
*/
|
|
|
|
tsleep((caddr_t) &vm_pages_needed, PVM, "psleep", 0);
|
|
cnt.v_pdwakeups++;
|
|
|
|
vm_pager_sync();
|
|
/*
|
|
* The force wakeup hack added to eliminate delays and potiential
|
|
* deadlock. It was possible for the page daemon to indefintely
|
|
* postpone waking up a process that it might be waiting for memory
|
|
* on. The putmulti stuff seems to have aggravated the situation.
|
|
*/
|
|
force_wakeup = vm_pageout_scan();
|
|
vm_pager_sync();
|
|
if( force_wakeup)
|
|
wakeup( (caddr_t) &cnt.v_free_count);
|
|
wakeup((caddr_t) kmem_map);
|
|
}
|
|
}
|
|
|