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freebsd-dev/sys/vm/vm_page.c

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/*
* Copyright (c) 1991 Regents of the University of California.
* 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_page.c 7.4 (Berkeley) 5/7/91
* $Id: vm_page.c,v 1.103 1998/07/11 07:46:14 bde Exp $
*/
/*
* 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.
*/
/*
* Resident memory management module.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <sys/lock.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_extern.h>
static void vm_page_queue_init __P((void));
static vm_page_t vm_page_select_free __P((vm_object_t object,
vm_pindex_t pindex, int prefqueue));
static vm_page_t vm_page_select_cache __P((vm_object_t, vm_pindex_t));
/*
* Associated with page of user-allocatable memory is a
* page structure.
*/
static struct pglist *vm_page_buckets; /* Array of buckets */
static int vm_page_bucket_count; /* How big is array? */
static int vm_page_hash_mask; /* Mask for hash function */
static volatile int vm_page_bucket_generation;
struct pglist vm_page_queue_free[PQ_L2_SIZE] = {0};
struct pglist vm_page_queue_zero[PQ_L2_SIZE] = {0};
struct pglist vm_page_queue_active = {0};
struct pglist vm_page_queue_inactive = {0};
struct pglist vm_page_queue_cache[PQ_L2_SIZE] = {0};
static int no_queue=0;
struct vpgqueues vm_page_queues[PQ_COUNT] = {0};
static int pqcnt[PQ_COUNT] = {0};
static void
vm_page_queue_init(void) {
int i;
vm_page_queues[PQ_NONE].pl = NULL;
vm_page_queues[PQ_NONE].cnt = &no_queue;
for(i=0;i<PQ_L2_SIZE;i++) {
vm_page_queues[PQ_FREE+i].pl = &vm_page_queue_free[i];
vm_page_queues[PQ_FREE+i].cnt = &cnt.v_free_count;
}
for(i=0;i<PQ_L2_SIZE;i++) {
vm_page_queues[PQ_ZERO+i].pl = &vm_page_queue_zero[i];
vm_page_queues[PQ_ZERO+i].cnt = &cnt.v_free_count;
}
vm_page_queues[PQ_INACTIVE].pl = &vm_page_queue_inactive;
vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count;
vm_page_queues[PQ_ACTIVE].pl = &vm_page_queue_active;
vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count;
for(i=0;i<PQ_L2_SIZE;i++) {
vm_page_queues[PQ_CACHE+i].pl = &vm_page_queue_cache[i];
vm_page_queues[PQ_CACHE+i].cnt = &cnt.v_cache_count;
}
for(i=0;i<PQ_COUNT;i++) {
if (vm_page_queues[i].pl) {
TAILQ_INIT(vm_page_queues[i].pl);
} else if (i != 0) {
panic("vm_page_queue_init: queue %d is null", i);
}
vm_page_queues[i].lcnt = &pqcnt[i];
}
}
vm_page_t vm_page_array = 0;
static int vm_page_array_size = 0;
long first_page = 0;
static long last_page;
static vm_size_t page_mask;
static int page_shift;
int vm_page_zero_count = 0;
/*
* map of contiguous valid DEV_BSIZE chunks in a page
* (this list is valid for page sizes upto 16*DEV_BSIZE)
*/
static u_short vm_page_dev_bsize_chunks[] = {
0x0, 0x1, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff,
0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff
};
static __inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex));
static int vm_page_freechk_and_unqueue __P((vm_page_t m));
static void vm_page_free_wakeup __P((void));
/*
* vm_set_page_size:
*
* Sets the page size, perhaps based upon the memory
* size. Must be called before any use of page-size
* dependent functions.
*
* Sets page_shift and page_mask from cnt.v_page_size.
*/
void
vm_set_page_size()
{
if (cnt.v_page_size == 0)
cnt.v_page_size = DEFAULT_PAGE_SIZE;
page_mask = cnt.v_page_size - 1;
if ((page_mask & cnt.v_page_size) != 0)
panic("vm_set_page_size: page size not a power of two");
for (page_shift = 0;; page_shift++)
if ((1 << page_shift) == cnt.v_page_size)
break;
}
/*
* vm_page_startup:
*
* Initializes the resident memory module.
*
* Allocates memory for the page cells, and
* for the object/offset-to-page hash table headers.
* Each page cell is initialized and placed on the free list.
*/
vm_offset_t
vm_page_startup(starta, enda, vaddr)
register vm_offset_t starta;
vm_offset_t enda;
register vm_offset_t vaddr;
{
register vm_offset_t mapped;
register vm_page_t m;
register struct pglist *bucket;
vm_size_t npages, page_range;
register vm_offset_t new_start;
int i;
vm_offset_t pa;
int nblocks;
vm_offset_t first_managed_page;
/* the biggest memory array is the second group of pages */
vm_offset_t start;
vm_offset_t biggestone, biggestsize;
vm_offset_t total;
total = 0;
biggestsize = 0;
biggestone = 0;
nblocks = 0;
vaddr = round_page(vaddr);
for (i = 0; phys_avail[i + 1]; i += 2) {
phys_avail[i] = round_page(phys_avail[i]);
phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
}
for (i = 0; phys_avail[i + 1]; i += 2) {
int size = phys_avail[i + 1] - phys_avail[i];
if (size > biggestsize) {
biggestone = i;
biggestsize = size;
}
++nblocks;
total += size;
}
start = phys_avail[biggestone];
/*
* Initialize the queue headers for the free queue, the active queue
* and the inactive queue.
*/
vm_page_queue_init();
/*
* Allocate (and initialize) the hash table buckets.
*
* The number of buckets MUST BE a power of 2, and the actual value is
* the next power of 2 greater than the number of physical pages in
* the system.
*
* Note: This computation can be tweaked if desired.
*/
vm_page_buckets = (struct pglist *) vaddr;
bucket = vm_page_buckets;
if (vm_page_bucket_count == 0) {
vm_page_bucket_count = 1;
while (vm_page_bucket_count < atop(total))
vm_page_bucket_count <<= 1;
}
vm_page_hash_mask = vm_page_bucket_count - 1;
/*
* Validate these addresses.
*/
new_start = start + vm_page_bucket_count * sizeof(struct pglist);
new_start = round_page(new_start);
mapped = round_page(vaddr);
vaddr = pmap_map(mapped, start, new_start,
VM_PROT_READ | VM_PROT_WRITE);
start = new_start;
vaddr = round_page(vaddr);
bzero((caddr_t) mapped, vaddr - mapped);
for (i = 0; i < vm_page_bucket_count; i++) {
TAILQ_INIT(bucket);
bucket++;
}
/*
* Compute the number of pages of memory that will be available for
* use (taking into account the overhead of a page structure per
* page).
*/
first_page = phys_avail[0] / PAGE_SIZE;
last_page = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE;
page_range = last_page - (phys_avail[0] / PAGE_SIZE);
npages = (total - (page_range * sizeof(struct vm_page)) -
(start - phys_avail[biggestone])) / PAGE_SIZE;
/*
* Initialize the mem entry structures now, and put them in the free
* queue.
*/
vm_page_array = (vm_page_t) vaddr;
mapped = vaddr;
/*
* Validate these addresses.
*/
new_start = round_page(start + page_range * sizeof(struct vm_page));
mapped = pmap_map(mapped, start, new_start,
VM_PROT_READ | VM_PROT_WRITE);
start = new_start;
first_managed_page = start / PAGE_SIZE;
/*
* Clear all of the page structures
*/
bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
vm_page_array_size = page_range;
cnt.v_page_count = 0;
cnt.v_free_count = 0;
for (i = 0; phys_avail[i + 1] && npages > 0; i += 2) {
if (i == biggestone)
pa = ptoa(first_managed_page);
else
pa = phys_avail[i];
while (pa < phys_avail[i + 1] && npages-- > 0) {
++cnt.v_page_count;
++cnt.v_free_count;
m = PHYS_TO_VM_PAGE(pa);
m->phys_addr = pa;
m->flags = 0;
m->pc = (pa >> PAGE_SHIFT) & PQ_L2_MASK;
m->queue = m->pc + PQ_FREE;
TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq);
++(*vm_page_queues[m->queue].lcnt);
pa += PAGE_SIZE;
}
}
return (mapped);
}
/*
* vm_page_hash:
*
* Distributes the object/offset key pair among hash buckets.
*
* NOTE: This macro depends on vm_page_bucket_count being a power of 2.
*/
static __inline int
vm_page_hash(object, pindex)
vm_object_t object;
vm_pindex_t pindex;
{
return ((((uintptr_t) object) >> 5) + (pindex >> 1)) & vm_page_hash_mask;
}
/*
* vm_page_insert: [ internal use only ]
*
* Inserts the given mem entry into the object/object-page
* table and object list.
*
* The object and page must be locked, and must be splhigh.
*/
void
vm_page_insert(m, object, pindex)
register vm_page_t m;
register vm_object_t object;
register vm_pindex_t pindex;
{
register struct pglist *bucket;
#if !defined(MAX_PERF)
if (m->flags & PG_TABLED)
panic("vm_page_insert: already inserted");
#endif
/*
* Record the object/offset pair in this page
*/
m->object = object;
m->pindex = pindex;
/*
* Insert it into the object_object/offset hash table
*/
bucket = &vm_page_buckets[vm_page_hash(object, pindex)];
TAILQ_INSERT_TAIL(bucket, m, hashq);
vm_page_bucket_generation++;
/*
* Now link into the object's list of backed pages.
*/
TAILQ_INSERT_TAIL(&object->memq, m, listq);
m->flags |= PG_TABLED;
m->object->page_hint = m;
m->object->generation++;
if (m->wire_count)
object->wire_count++;
if ((m->queue - m->pc) == PQ_CACHE)
object->cache_count++;
/*
* And show that the object has one more resident page.
*/
object->resident_page_count++;
}
/*
* vm_page_remove: [ internal use only ]
* NOTE: used by device pager as well -wfj
*
* Removes the given mem entry from the object/offset-page
* table and the object page list.
*
* The object and page must be locked, and at splhigh.
*/
void
vm_page_remove(m)
register vm_page_t m;
{
register struct pglist *bucket;
vm_object_t object;
if (!(m->flags & PG_TABLED))
return;
#if !defined(MAX_PERF)
if ((m->flags & PG_BUSY) == 0) {
panic("vm_page_remove: page not busy");
}
#endif
m->flags &= ~PG_BUSY;
if (m->flags & PG_WANTED) {
m->flags &= ~PG_WANTED;
wakeup(m);
}
object = m->object;
if (object->page_hint == m)
object->page_hint = NULL;
if (m->wire_count)
object->wire_count--;
if ((m->queue - m->pc) == PQ_CACHE)
object->cache_count--;
/*
* Remove from the object_object/offset hash table
*/
bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)];
TAILQ_REMOVE(bucket, m, hashq);
vm_page_bucket_generation++;
/*
* Now remove from the object's list of backed pages.
*/
TAILQ_REMOVE(&object->memq, m, listq);
/*
* And show that the object has one fewer resident page.
*/
object->resident_page_count--;
object->generation++;
m->object = NULL;
m->flags &= ~PG_TABLED;
}
/*
* vm_page_lookup:
*
* Returns the page associated with the object/offset
* pair specified; if none is found, NULL is returned.
*
* The object must be locked. No side effects.
*/
vm_page_t
vm_page_lookup(object, pindex)
register vm_object_t object;
register vm_pindex_t pindex;
{
register vm_page_t m;
register struct pglist *bucket;
int generation;
int s;
/*
* Search the hash table for this object/offset pair
*/
if (object->page_hint && (object->page_hint->pindex == pindex) &&
(object->page_hint->object == object))
return object->page_hint;
retry:
generation = vm_page_bucket_generation;
bucket = &vm_page_buckets[vm_page_hash(object, pindex)];
for (m = TAILQ_FIRST(bucket); m != NULL; m = TAILQ_NEXT(m,hashq)) {
if ((m->object == object) && (m->pindex == pindex)) {
if (vm_page_bucket_generation != generation)
goto retry;
m->object->page_hint = m;
return (m);
}
}
if (vm_page_bucket_generation != generation)
goto retry;
return (NULL);
}
/*
* vm_page_rename:
*
* Move the given memory entry from its
* current object to the specified target object/offset.
*
* The object must be locked.
*/
void
vm_page_rename(m, new_object, new_pindex)
register vm_page_t m;
register vm_object_t new_object;
vm_pindex_t new_pindex;
{
int s;
s = splvm();
vm_page_remove(m);
vm_page_insert(m, new_object, new_pindex);
splx(s);
}
/*
* vm_page_unqueue without any wakeup
*/
void
vm_page_unqueue_nowakeup(m)
vm_page_t m;
{
int queue = m->queue;
struct vpgqueues *pq;
if (queue != PQ_NONE) {
pq = &vm_page_queues[queue];
m->queue = PQ_NONE;
TAILQ_REMOVE(pq->pl, m, pageq);
(*pq->cnt)--;
(*pq->lcnt)--;
if ((queue - m->pc) == PQ_CACHE) {
if (m->object)
m->object->cache_count--;
}
}
}
/*
* vm_page_unqueue must be called at splhigh();
*/
void
vm_page_unqueue(m)
vm_page_t m;
{
int queue = m->queue;
struct vpgqueues *pq;
if (queue != PQ_NONE) {
m->queue = PQ_NONE;
pq = &vm_page_queues[queue];
TAILQ_REMOVE(pq->pl, m, pageq);
(*pq->cnt)--;
(*pq->lcnt)--;
if ((queue - m->pc) == PQ_CACHE) {
if ((cnt.v_cache_count + cnt.v_free_count) <
(cnt.v_free_reserved + cnt.v_cache_min))
pagedaemon_wakeup();
if (m->object)
m->object->cache_count--;
}
}
}
/*
* Find a page on the specified queue with color optimization.
*/
vm_page_t
vm_page_list_find(basequeue, index)
int basequeue, index;
{
#if PQ_L2_SIZE > 1
int i,j;
vm_page_t m;
int hindex;
struct vpgqueues *pq;
pq = &vm_page_queues[basequeue];
m = TAILQ_FIRST(pq[index].pl);
if (m)
return m;
for(j = 0; j < PQ_L1_SIZE; j++) {
int ij;
for(i = (PQ_L2_SIZE / 2) - PQ_L1_SIZE;
(ij = i + j) > 0;
i -= PQ_L1_SIZE) {
hindex = index + ij;
if (hindex >= PQ_L2_SIZE)
hindex -= PQ_L2_SIZE;
if (m = TAILQ_FIRST(pq[hindex].pl))
return m;
hindex = index - ij;
if (hindex < 0)
hindex += PQ_L2_SIZE;
if (m = TAILQ_FIRST(pq[hindex].pl))
return m;
}
}
hindex = index + PQ_L2_SIZE / 2;
if (hindex >= PQ_L2_SIZE)
hindex -= PQ_L2_SIZE;
m = TAILQ_FIRST(pq[hindex].pl);
if (m)
return m;
return NULL;
#else
return TAILQ_FIRST(vm_page_queues[basequeue].pl);
#endif
}
/*
* Find a page on the specified queue with color optimization.
*/
vm_page_t
vm_page_select(object, pindex, basequeue)
vm_object_t object;
vm_pindex_t pindex;
int basequeue;
{
#if PQ_L2_SIZE > 1
int index;
index = (pindex + object->pg_color) & PQ_L2_MASK;
return vm_page_list_find(basequeue, index);
#else
return TAILQ_FIRST(vm_page_queues[basequeue].pl);
#endif
}
/*
* Find a page on the cache queue with color optimization. As pages
* might be found, but not applicable, they are deactivated. This
* keeps us from using potentially busy cached pages.
*/
vm_page_t
vm_page_select_cache(object, pindex)
vm_object_t object;
vm_pindex_t pindex;
{
vm_page_t m;
while (TRUE) {
#if PQ_L2_SIZE > 1
int index;
index = (pindex + object->pg_color) & PQ_L2_MASK;
m = vm_page_list_find(PQ_CACHE, index);
#else
m = TAILQ_FIRST(vm_page_queues[PQ_CACHE].pl);
#endif
if (m && ((m->flags & PG_BUSY) || m->busy ||
m->hold_count || m->wire_count)) {
vm_page_deactivate(m);
continue;
}
return m;
}
}
/*
* Find a free or zero page, with specified preference.
*/
static vm_page_t
vm_page_select_free(object, pindex, prefqueue)
vm_object_t object;
vm_pindex_t pindex;
int prefqueue;
{
#if PQ_L2_SIZE > 1
int i,j;
int index, hindex;
#endif
vm_page_t m, mh;
int oqueuediff;
struct vpgqueues *pq;
if (prefqueue == PQ_ZERO)
oqueuediff = PQ_FREE - PQ_ZERO;
else
oqueuediff = PQ_ZERO - PQ_FREE;
if (mh = object->page_hint) {
if (mh->pindex == (pindex - 1)) {
if ((mh->flags & PG_FICTITIOUS) == 0) {
if ((mh < &vm_page_array[cnt.v_page_count-1]) &&
(mh >= &vm_page_array[0])) {
int queue;
m = mh + 1;
if (VM_PAGE_TO_PHYS(m) == (VM_PAGE_TO_PHYS(mh) + PAGE_SIZE)) {
queue = m->queue - m->pc;
if (queue == PQ_FREE || queue == PQ_ZERO) {
return m;
}
}
}
}
}
}
pq = &vm_page_queues[prefqueue];
#if PQ_L2_SIZE > 1
index = (pindex + object->pg_color) & PQ_L2_MASK;
if (m = TAILQ_FIRST(pq[index].pl))
return m;
if (m = TAILQ_FIRST(pq[index + oqueuediff].pl))
return m;
for(j = 0; j < PQ_L1_SIZE; j++) {
int ij;
for(i = (PQ_L2_SIZE / 2) - PQ_L1_SIZE;
(ij = i + j) >= 0;
i -= PQ_L1_SIZE) {
hindex = index + ij;
if (hindex >= PQ_L2_SIZE)
hindex -= PQ_L2_SIZE;
if (m = TAILQ_FIRST(pq[hindex].pl))
return m;
if (m = TAILQ_FIRST(pq[hindex + oqueuediff].pl))
return m;
hindex = index - ij;
if (hindex < 0)
hindex += PQ_L2_SIZE;
if (m = TAILQ_FIRST(pq[hindex].pl))
return m;
if (m = TAILQ_FIRST(pq[hindex + oqueuediff].pl))
return m;
}
}
hindex = index + PQ_L2_SIZE / 2;
if (hindex >= PQ_L2_SIZE)
hindex -= PQ_L2_SIZE;
if (m = TAILQ_FIRST(pq[hindex].pl))
return m;
if (m = TAILQ_FIRST(pq[hindex+oqueuediff].pl))
return m;
#else
if (m = TAILQ_FIRST(pq[0].pl))
return m;
else
return TAILQ_FIRST(pq[oqueuediff].pl);
#endif
return NULL;
}
/*
* vm_page_alloc:
*
* Allocate and return a memory cell associated
* with this VM object/offset pair.
*
* page_req classes:
* VM_ALLOC_NORMAL normal process request
* VM_ALLOC_SYSTEM system *really* needs a page
* VM_ALLOC_INTERRUPT interrupt time request
* VM_ALLOC_ZERO zero page
*
* Object must be locked.
*/
vm_page_t
vm_page_alloc(object, pindex, page_req)
vm_object_t object;
vm_pindex_t pindex;
int page_req;
{
register vm_page_t m;
struct vpgqueues *pq;
vm_object_t oldobject;
int queue, qtype;
int s;
#ifdef DIAGNOSTIC
m = vm_page_lookup(object, pindex);
if (m)
panic("vm_page_alloc: page already allocated");
#endif
if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) {
page_req = VM_ALLOC_SYSTEM;
};
s = splvm();
switch (page_req) {
case VM_ALLOC_NORMAL:
if (cnt.v_free_count >= cnt.v_free_reserved) {
m = vm_page_select_free(object, pindex, PQ_FREE);
#if defined(DIAGNOSTIC)
if (m == NULL)
panic("vm_page_alloc(NORMAL): missing page on free queue\n");
#endif
} else {
m = vm_page_select_cache(object, pindex);
if (m == NULL) {
splx(s);
#if defined(DIAGNOSTIC)
if (cnt.v_cache_count > 0)
printf("vm_page_alloc(NORMAL): missing pages on cache queue: %d\n", cnt.v_cache_count);
#endif
vm_pageout_deficit++;
pagedaemon_wakeup();
return (NULL);
}
}
break;
case VM_ALLOC_ZERO:
if (cnt.v_free_count >= cnt.v_free_reserved) {
m = vm_page_select_free(object, pindex, PQ_ZERO);
#if defined(DIAGNOSTIC)
if (m == NULL)
panic("vm_page_alloc(ZERO): missing page on free queue\n");
#endif
} else {
m = vm_page_select_cache(object, pindex);
if (m == NULL) {
splx(s);
#if defined(DIAGNOSTIC)
if (cnt.v_cache_count > 0)
printf("vm_page_alloc(ZERO): missing pages on cache queue: %d\n", cnt.v_cache_count);
#endif
vm_pageout_deficit++;
pagedaemon_wakeup();
return (NULL);
}
}
break;
case VM_ALLOC_SYSTEM:
if ((cnt.v_free_count >= cnt.v_free_reserved) ||
((cnt.v_cache_count == 0) &&
(cnt.v_free_count >= cnt.v_interrupt_free_min))) {
m = vm_page_select_free(object, pindex, PQ_FREE);
#if defined(DIAGNOSTIC)
if (m == NULL)
panic("vm_page_alloc(SYSTEM): missing page on free queue\n");
#endif
} else {
m = vm_page_select_cache(object, pindex);
if (m == NULL) {
splx(s);
#if defined(DIAGNOSTIC)
if (cnt.v_cache_count > 0)
printf("vm_page_alloc(SYSTEM): missing pages on cache queue: %d\n", cnt.v_cache_count);
#endif
vm_pageout_deficit++;
pagedaemon_wakeup();
return (NULL);
}
}
break;
case VM_ALLOC_INTERRUPT:
if (cnt.v_free_count > 0) {
m = vm_page_select_free(object, pindex, PQ_FREE);
#if defined(DIAGNOSTIC)
if (m == NULL)
panic("vm_page_alloc(INTERRUPT): missing page on free queue\n");
#endif
} else {
splx(s);
vm_pageout_deficit++;
pagedaemon_wakeup();
return (NULL);
}
break;
default:
m = NULL;
#if !defined(MAX_PERF)
panic("vm_page_alloc: invalid allocation class");
#endif
}
queue = m->queue;
qtype = queue - m->pc;
if (qtype == PQ_ZERO)
vm_page_zero_count--;
pq = &vm_page_queues[queue];
TAILQ_REMOVE(pq->pl, m, pageq);
(*pq->cnt)--;
(*pq->lcnt)--;
oldobject = NULL;
if (qtype == PQ_ZERO) {
m->flags = PG_ZERO | PG_BUSY;
} else if (qtype == PQ_CACHE) {
oldobject = m->object;
m->flags |= PG_BUSY;
vm_page_remove(m);
m->flags = PG_BUSY;
} else {
m->flags = PG_BUSY;
}
m->wire_count = 0;
m->hold_count = 0;
m->act_count = 0;
m->busy = 0;
m->valid = 0;
m->dirty = 0;
m->queue = PQ_NONE;
/* XXX before splx until vm_page_insert is safe */
vm_page_insert(m, object, pindex);
/*
* Don't wakeup too often - wakeup the pageout daemon when
* we would be nearly out of memory.
*/
if (((cnt.v_free_count + cnt.v_cache_count) <
(cnt.v_free_reserved + cnt.v_cache_min)) ||
(cnt.v_free_count < cnt.v_pageout_free_min))
pagedaemon_wakeup();
if ((qtype == PQ_CACHE) &&
((page_req == VM_ALLOC_NORMAL) || (page_req == VM_ALLOC_ZERO)) &&
oldobject && (oldobject->type == OBJT_VNODE) &&
((oldobject->flags & OBJ_DEAD) == 0)) {
struct vnode *vp;
vp = (struct vnode *) oldobject->handle;
if (vp && VSHOULDFREE(vp)) {
if ((vp->v_flag & (VFREE|VTBFREE|VDOOMED)) == 0) {
TAILQ_INSERT_TAIL(&vnode_tobefree_list, vp, v_freelist);
vp->v_flag |= VTBFREE;
}
}
}
splx(s);
return (m);
}
void
vm_wait()
{
int s;
s = splvm();
if (curproc == pageproc) {
vm_pageout_pages_needed = 1;
tsleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0);
} else {
if (!vm_pages_needed) {
vm_pages_needed++;
wakeup(&vm_pages_needed);
}
tsleep(&cnt.v_free_count, PVM, "vmwait", 0);
}
splx(s);
}
int
vm_page_sleep(vm_page_t m, char *msg, char *busy) {
vm_object_t object = m->object;
int slept = 0;
if ((busy && *busy) || (m->flags & PG_BUSY)) {
int s;
s = splvm();
if ((busy && *busy) || (m->flags & PG_BUSY)) {
m->flags |= PG_WANTED;
tsleep(m, PVM, msg, 0);
slept = 1;
}
splx(s);
}
return slept;
}
/*
* vm_page_activate:
*
* Put the specified page on the active list (if appropriate).
*
* The page queues must be locked.
*/
void
vm_page_activate(m)
register vm_page_t m;
{
int s;
vm_page_t np;
vm_object_t object;
s = splvm();
if (m->queue != PQ_ACTIVE) {
if ((m->queue - m->pc) == PQ_CACHE)
cnt.v_reactivated++;
vm_page_unqueue(m);
if (m->wire_count == 0) {
m->queue = PQ_ACTIVE;
++(*vm_page_queues[PQ_ACTIVE].lcnt);
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
if (m->act_count < ACT_INIT)
m->act_count = ACT_INIT;
cnt.v_active_count++;
}
} else {
if (m->act_count < ACT_INIT)
m->act_count = ACT_INIT;
}
splx(s);
}
/*
* helper routine for vm_page_free and vm_page_free_zero
*/
static int
vm_page_freechk_and_unqueue(m)
vm_page_t m;
{
vm_object_t oldobject;
oldobject = m->object;
#if !defined(MAX_PERF)
if (m->busy || ((m->queue - m->pc) == PQ_FREE) ||
(m->hold_count != 0)) {
printf(
"vm_page_free: pindex(%lu), busy(%d), PG_BUSY(%d), hold(%d)\n",
(u_long)m->pindex, m->busy, (m->flags & PG_BUSY) ? 1 : 0,
m->hold_count);
if ((m->queue - m->pc) == PQ_FREE)
panic("vm_page_free: freeing free page");
else
panic("vm_page_free: freeing busy page");
}
#endif
vm_page_unqueue_nowakeup(m);
vm_page_remove(m);
if ((m->flags & PG_FICTITIOUS) != 0) {
return 0;
}
m->valid = 0;
if (m->wire_count != 0) {
#if !defined(MAX_PERF)
if (m->wire_count > 1) {
panic("vm_page_free: invalid wire count (%d), pindex: 0x%x",
m->wire_count, m->pindex);
}
#endif
m->wire_count = 0;
if (m->object)
m->object->wire_count--;
cnt.v_wire_count--;
}
if (oldobject && (oldobject->type == OBJT_VNODE) &&
((oldobject->flags & OBJ_DEAD) == 0)) {
struct vnode *vp;
vp = (struct vnode *) oldobject->handle;
if (vp && VSHOULDFREE(vp)) {
if ((vp->v_flag & (VTBFREE|VDOOMED|VFREE)) == 0) {
TAILQ_INSERT_TAIL(&vnode_tobefree_list, vp, v_freelist);
vp->v_flag |= VTBFREE;
}
}
}
return 1;
}
/*
* helper routine for vm_page_free and vm_page_free_zero
*/
static __inline void
vm_page_free_wakeup()
{
/*
* if pageout daemon needs pages, then tell it that there are
* some free.
*/
if (vm_pageout_pages_needed) {
wakeup(&vm_pageout_pages_needed);
vm_pageout_pages_needed = 0;
}
/*
* wakeup processes that are waiting on memory if we hit a
* high water mark. And wakeup scheduler process if we have
* lots of memory. this process will swapin processes.
*/
if (vm_pages_needed &&
((cnt.v_free_count + cnt.v_cache_count) >= cnt.v_free_min)) {
wakeup(&cnt.v_free_count);
vm_pages_needed = 0;
}
}
/*
* vm_page_free:
*
* Returns the given page to the free list,
* disassociating it with any VM object.
*
* Object and page must be locked prior to entry.
*/
void
vm_page_free(m)
register vm_page_t m;
{
int s;
struct vpgqueues *pq;
s = splvm();
cnt.v_tfree++;
if (!vm_page_freechk_and_unqueue(m)) {
splx(s);
return;
}
m->queue = PQ_FREE + m->pc;
pq = &vm_page_queues[m->queue];
++(*pq->lcnt);
++(*pq->cnt);
/*
* If the pageout process is grabbing the page, it is likely
* that the page is NOT in the cache. It is more likely that
* the page will be partially in the cache if it is being
* explicitly freed.
*/
if (curproc == pageproc) {
TAILQ_INSERT_TAIL(pq->pl, m, pageq);
} else {
TAILQ_INSERT_HEAD(pq->pl, m, pageq);
}
vm_page_free_wakeup();
splx(s);
}
void
vm_page_free_zero(m)
register vm_page_t m;
{
int s;
struct vpgqueues *pq;
s = splvm();
cnt.v_tfree++;
if (!vm_page_freechk_and_unqueue(m)) {
splx(s);
return;
}
m->queue = PQ_ZERO + m->pc;
pq = &vm_page_queues[m->queue];
++(*pq->lcnt);
++(*pq->cnt);
TAILQ_INSERT_HEAD(pq->pl, m, pageq);
++vm_page_zero_count;
vm_page_free_wakeup();
splx(s);
}
/*
* vm_page_wire:
*
* Mark this page as wired down by yet
* another map, removing it from paging queues
* as necessary.
*
* The page queues must be locked.
*/
void
vm_page_wire(m)
register vm_page_t m;
{
int s;
if (m->wire_count == 0) {
s = splvm();
vm_page_unqueue(m);
splx(s);
cnt.v_wire_count++;
if (m->object)
m->object->wire_count++;
}
(*vm_page_queues[PQ_NONE].lcnt)++;
m->wire_count++;
m->flags |= PG_MAPPED;
}
/*
* vm_page_unwire:
*
* Release one wiring of this page, potentially
* enabling it to be paged again.
*
* The page queues must be locked.
*/
void
vm_page_unwire(m)
register vm_page_t m;
{
int s;
s = splvm();
if (m->wire_count > 0) {
m->wire_count--;
if (m->wire_count == 0) {
if (m->object)
m->object->wire_count--;
cnt.v_wire_count--;
TAILQ_INSERT_TAIL(&vm_page_queue_active, m, pageq);
m->queue = PQ_ACTIVE;
(*vm_page_queues[PQ_ACTIVE].lcnt)++;
cnt.v_active_count++;
}
} else {
#if !defined(MAX_PERF)
panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count);
#endif
}
splx(s);
}
/*
* vm_page_deactivate:
*
* Returns the given page to the inactive list,
* indicating that no physical maps have access
* to this page. [Used by the physical mapping system.]
*
* The page queues must be locked.
*/
void
vm_page_deactivate(m)
register vm_page_t m;
{
int s;
/*
* Only move active pages -- ignore locked or already inactive ones.
*
* XXX: sometimes we get pages which aren't wired down or on any queue -
* we need to put them on the inactive queue also, otherwise we lose
* track of them. Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93.
*/
if (m->queue == PQ_INACTIVE)
return;
s = splvm();
if (m->wire_count == 0) {
if ((m->queue - m->pc) == PQ_CACHE)
cnt.v_reactivated++;
vm_page_unqueue(m);
TAILQ_INSERT_TAIL(&vm_page_queue_inactive, m, pageq);
m->queue = PQ_INACTIVE;
++(*vm_page_queues[PQ_INACTIVE].lcnt);
cnt.v_inactive_count++;
}
splx(s);
}
/*
* vm_page_cache
*
* Put the specified page onto the page cache queue (if appropriate).
*/
void
vm_page_cache(m)
register vm_page_t m;
{
int s;
#if !defined(MAX_PERF)
if ((m->flags & PG_BUSY) || m->busy || m->wire_count) {
printf("vm_page_cache: attempting to cache busy page\n");
return;
}
#endif
if ((m->queue - m->pc) == PQ_CACHE)
return;
vm_page_protect(m, VM_PROT_NONE);
#if !defined(MAX_PERF)
if (m->dirty != 0) {
panic("vm_page_cache: caching a dirty page, pindex: %d", m->pindex);
}
#endif
s = splvm();
vm_page_unqueue_nowakeup(m);
m->queue = PQ_CACHE + m->pc;
(*vm_page_queues[m->queue].lcnt)++;
TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, pageq);
cnt.v_cache_count++;
m->object->cache_count++;
vm_page_free_wakeup();
splx(s);
}
/*
* Grab a page, waiting until we are waken up due to the page
* changing state. We keep on waiting, if the page continues
* to be in the object. If the page doesn't exist, allocate it.
*/
vm_page_t
vm_page_grab(object, pindex, allocflags)
vm_object_t object;
vm_pindex_t pindex;
int allocflags;
{
vm_page_t m;
int s, generation;
retrylookup:
if ((m = vm_page_lookup(object, pindex)) != NULL) {
if (m->busy || (m->flags & PG_BUSY)) {
generation = object->generation;
s = splvm();
while ((object->generation == generation) &&
(m->busy || (m->flags & PG_BUSY))) {
m->flags |= PG_WANTED | PG_REFERENCED;
tsleep(m, PVM, "pgrbwt", 0);
if ((allocflags & VM_ALLOC_RETRY) == 0) {
splx(s);
return NULL;
}
}
splx(s);
goto retrylookup;
} else {
m->flags |= PG_BUSY;
return m;
}
}
m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY);
if (m == NULL) {
VM_WAIT;
if ((allocflags & VM_ALLOC_RETRY) == 0)
return NULL;
goto retrylookup;
}
return m;
}
/*
* mapping function for valid bits or for dirty bits in
* a page
*/
__inline int
vm_page_bits(int base, int size)
{
u_short chunk;
if ((base == 0) && (size >= PAGE_SIZE))
return VM_PAGE_BITS_ALL;
size = (size + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1);
base &= PAGE_MASK;
if (size > PAGE_SIZE - base) {
size = PAGE_SIZE - base;
}
base = base / DEV_BSIZE;
chunk = vm_page_dev_bsize_chunks[size / DEV_BSIZE];
return (chunk << base) & VM_PAGE_BITS_ALL;
}
/*
* set a page valid and clean
*/
void
vm_page_set_validclean(m, base, size)
vm_page_t m;
int base;
int size;
{
int pagebits = vm_page_bits(base, size);
m->valid |= pagebits;
m->dirty &= ~pagebits;
if( base == 0 && size == PAGE_SIZE)
pmap_clear_modify(VM_PAGE_TO_PHYS(m));
}
/*
* set a page (partially) invalid
*/
void
vm_page_set_invalid(m, base, size)
vm_page_t m;
int base;
int size;
{
int bits;
m->valid &= ~(bits = vm_page_bits(base, size));
if (m->valid == 0)
m->dirty &= ~bits;
m->object->generation++;
}
/*
* is (partial) page valid?
*/
int
vm_page_is_valid(m, base, size)
vm_page_t m;
int base;
int size;
{
int bits = vm_page_bits(base, size);
if (m->valid && ((m->valid & bits) == bits))
return 1;
else
return 0;
}
void
vm_page_test_dirty(m)
vm_page_t m;
{
if ((m->dirty != VM_PAGE_BITS_ALL) &&
pmap_is_modified(VM_PAGE_TO_PHYS(m))) {
m->dirty = VM_PAGE_BITS_ALL;
}
}
/*
* This interface is for merging with malloc() someday.
* Even if we never implement compaction so that contiguous allocation
* works after initialization time, malloc()'s data structures are good
* for statistics and for allocations of less than a page.
*/
void *
contigmalloc1(size, type, flags, low, high, alignment, boundary, map)
unsigned long size; /* should be size_t here and for malloc() */
struct malloc_type *type;
int flags;
unsigned long low;
unsigned long high;
unsigned long alignment;
unsigned long boundary;
vm_map_t map;
{
int i, s, start;
vm_offset_t addr, phys, tmp_addr;
int pass;
vm_page_t pga = vm_page_array;
size = round_page(size);
#if !defined(MAX_PERF)
if (size == 0)
panic("contigmalloc1: size must not be 0");
if ((alignment & (alignment - 1)) != 0)
panic("contigmalloc1: alignment must be a power of 2");
if ((boundary & (boundary - 1)) != 0)
panic("contigmalloc1: boundary must be a power of 2");
#endif
start = 0;
for (pass = 0; pass <= 1; pass++) {
s = splvm();
again:
/*
* Find first page in array that is free, within range, aligned, and
* such that the boundary won't be crossed.
*/
for (i = start; i < cnt.v_page_count; i++) {
int pqtype;
phys = VM_PAGE_TO_PHYS(&pga[i]);
pqtype = pga[i].queue - pga[i].pc;
if (((pqtype == PQ_ZERO) || (pqtype == PQ_FREE) || (pqtype == PQ_CACHE)) &&
(phys >= low) && (phys < high) &&
((phys & (alignment - 1)) == 0) &&
(((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0))
break;
}
/*
* If the above failed or we will exceed the upper bound, fail.
*/
if ((i == cnt.v_page_count) ||
((VM_PAGE_TO_PHYS(&pga[i]) + size) > high)) {
vm_page_t m, next;
again1:
for (m = TAILQ_FIRST(&vm_page_queue_inactive);
m != NULL;
m = next) {
if (m->queue != PQ_INACTIVE) {
break;
}
next = TAILQ_NEXT(m, pageq);
if (vm_page_sleep(m, "vpctw0", &m->busy))
goto again1;
vm_page_test_dirty(m);
if (m->dirty) {
if (m->object->type == OBJT_VNODE) {
vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc);
vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC);
VOP_UNLOCK(m->object->handle, 0, curproc);
goto again1;
} else if (m->object->type == OBJT_SWAP ||
m->object->type == OBJT_DEFAULT) {
vm_pageout_flush(&m, 1, 0);
goto again1;
}
}
if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0))
vm_page_cache(m);
}
for (m = TAILQ_FIRST(&vm_page_queue_active);
m != NULL;
m = next) {
if (m->queue != PQ_ACTIVE) {
break;
}
next = TAILQ_NEXT(m, pageq);
if (vm_page_sleep(m, "vpctw1", &m->busy))
goto again1;
vm_page_test_dirty(m);
if (m->dirty) {
if (m->object->type == OBJT_VNODE) {
vn_lock(m->object->handle, LK_EXCLUSIVE | LK_RETRY, curproc);
vm_object_page_clean(m->object, 0, 0, OBJPC_SYNC);
VOP_UNLOCK(m->object->handle, 0, curproc);
goto again1;
} else if (m->object->type == OBJT_SWAP ||
m->object->type == OBJT_DEFAULT) {
vm_pageout_flush(&m, 1, 0);
goto again1;
}
}
if ((m->dirty == 0) && (m->busy == 0) && (m->hold_count == 0))
vm_page_cache(m);
}
splx(s);
continue;
}
start = i;
/*
* Check successive pages for contiguous and free.
*/
for (i = start + 1; i < (start + size / PAGE_SIZE); i++) {
int pqtype;
pqtype = pga[i].queue - pga[i].pc;
if ((VM_PAGE_TO_PHYS(&pga[i]) !=
(VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)) ||
((pqtype != PQ_ZERO) && (pqtype != PQ_FREE) && (pqtype != PQ_CACHE))) {
start++;
goto again;
}
}
for (i = start; i < (start + size / PAGE_SIZE); i++) {
int pqtype;
vm_page_t m = &pga[i];
pqtype = m->queue - m->pc;
if (pqtype == PQ_CACHE) {
m->flags |= PG_BUSY;
vm_page_free(m);
}
TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq);
(*vm_page_queues[m->queue].lcnt)--;
cnt.v_free_count--;
m->valid = VM_PAGE_BITS_ALL;
m->flags = 0;
m->dirty = 0;
m->wire_count = 0;
m->busy = 0;
m->queue = PQ_NONE;
m->object = NULL;
vm_page_wire(m);
}
/*
* We've found a contiguous chunk that meets are requirements.
* Allocate kernel VM, unfree and assign the physical pages to it and
* return kernel VM pointer.
*/
tmp_addr = addr = kmem_alloc_pageable(map, size);
if (addr == 0) {
/*
* XXX We almost never run out of kernel virtual
* space, so we don't make the allocated memory
* above available.
*/
splx(s);
return (NULL);
}
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
vm_page_insert(m, kernel_object,
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
pmap_kenter(tmp_addr, VM_PAGE_TO_PHYS(m));
tmp_addr += PAGE_SIZE;
}
splx(s);
return ((void *)addr);
}
return NULL;
}
void *
contigmalloc(size, type, flags, low, high, alignment, boundary)
unsigned long size; /* should be size_t here and for malloc() */
struct malloc_type *type;
int flags;
unsigned long low;
unsigned long high;
unsigned long alignment;
unsigned long boundary;
{
return contigmalloc1(size, type, flags, low, high, alignment, boundary,
kernel_map);
}
vm_offset_t
vm_page_alloc_contig(size, low, high, alignment)
vm_offset_t size;
vm_offset_t low;
vm_offset_t high;
vm_offset_t alignment;
{
return ((vm_offset_t)contigmalloc1(size, M_DEVBUF, M_NOWAIT, low, high,
alignment, 0ul, kernel_map));
}
#include "opt_ddb.h"
#ifdef DDB
#include <sys/kernel.h>
#include <ddb/ddb.h>
DB_SHOW_COMMAND(page, vm_page_print_page_info)
{
db_printf("cnt.v_free_count: %d\n", cnt.v_free_count);
db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count);
db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count);
db_printf("cnt.v_active_count: %d\n", cnt.v_active_count);
db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count);
db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved);
db_printf("cnt.v_free_min: %d\n", cnt.v_free_min);
db_printf("cnt.v_free_target: %d\n", cnt.v_free_target);
db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min);
db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target);
}
DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
{
int i;
db_printf("PQ_FREE:");
for(i=0;i<PQ_L2_SIZE;i++) {
db_printf(" %d", *vm_page_queues[PQ_FREE + i].lcnt);
}
db_printf("\n");
db_printf("PQ_CACHE:");
for(i=0;i<PQ_L2_SIZE;i++) {
db_printf(" %d", *vm_page_queues[PQ_CACHE + i].lcnt);
}
db_printf("\n");
db_printf("PQ_ZERO:");
for(i=0;i<PQ_L2_SIZE;i++) {
db_printf(" %d", *vm_page_queues[PQ_ZERO + i].lcnt);
}
db_printf("\n");
db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n",
*vm_page_queues[PQ_ACTIVE].lcnt,
*vm_page_queues[PQ_INACTIVE].lcnt);
}
#endif /* DDB */
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