5c16c2a8f1
Requested by: Alan and Bruce
1915 lines
45 KiB
C
1915 lines
45 KiB
C
/*
|
|
* 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
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/*
|
|
* 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 <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_pager.h>
|
|
#include <vm/vm_extern.h>
|
|
|
|
static void vm_page_queue_init __P((void));
|
|
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 vm_page **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 vpgqueues vm_page_queues[PQ_COUNT];
|
|
|
|
static void
|
|
vm_page_queue_init(void) {
|
|
int i;
|
|
|
|
for(i=0;i<PQ_L2_SIZE;i++) {
|
|
vm_page_queues[PQ_FREE+i].cnt = &cnt.v_free_count;
|
|
}
|
|
vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count;
|
|
|
|
vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count;
|
|
for(i=0;i<PQ_L2_SIZE;i++) {
|
|
vm_page_queues[PQ_CACHE+i].cnt = &cnt.v_cache_count;
|
|
}
|
|
for(i=0;i<PQ_COUNT;i++) {
|
|
TAILQ_INIT(&vm_page_queues[i].pl);
|
|
}
|
|
}
|
|
|
|
vm_page_t vm_page_array = 0;
|
|
static int vm_page_array_size = 0;
|
|
long first_page = 0;
|
|
int vm_page_zero_count = 0;
|
|
|
|
static __inline int vm_page_hash __P((vm_object_t object, vm_pindex_t pindex));
|
|
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.
|
|
*/
|
|
void
|
|
vm_set_page_size()
|
|
{
|
|
if (cnt.v_page_size == 0)
|
|
cnt.v_page_size = PAGE_SIZE;
|
|
if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0)
|
|
panic("vm_set_page_size: page size not a power of two");
|
|
}
|
|
|
|
/*
|
|
* 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 vm_page **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.
|
|
*
|
|
* We make the hash table approximately 2x the number of pages to
|
|
* reduce the chain length. This is about the same size using the
|
|
* singly-linked list as the 1x hash table we were using before
|
|
* using TAILQ but the chain length will be smaller.
|
|
*
|
|
* Note: This computation can be tweaked if desired.
|
|
*/
|
|
vm_page_buckets = (struct vm_page **)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_bucket_count <<= 1;
|
|
vm_page_hash_mask = vm_page_bucket_count - 1;
|
|
|
|
/*
|
|
* Validate these addresses.
|
|
*/
|
|
|
|
new_start = start + vm_page_bucket_count * sizeof(struct vm_page *);
|
|
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++) {
|
|
*bucket = NULL;
|
|
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;
|
|
|
|
page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE - first_page;
|
|
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;
|
|
|
|
/*
|
|
* Construct the free queue(s) in descending order (by physical
|
|
* address) so that the first 16MB of physical memory is allocated
|
|
* last rather than first. On large-memory machines, this avoids
|
|
* the exhaustion of low physical memory before isa_dmainit has run.
|
|
*/
|
|
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_HEAD(&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.
|
|
* This routine may not block.
|
|
*
|
|
* We try to randomize the hash based on the object to spread the pages
|
|
* out in the hash table without it costing us too much.
|
|
*/
|
|
static __inline int
|
|
vm_page_hash(object, pindex)
|
|
vm_object_t object;
|
|
vm_pindex_t pindex;
|
|
{
|
|
int i = ((uintptr_t)object + pindex) ^ object->hash_rand;
|
|
|
|
return(i & vm_page_hash_mask);
|
|
}
|
|
|
|
/*
|
|
* vm_page_insert: [ internal use only ]
|
|
*
|
|
* Inserts the given mem entry into the object and object list.
|
|
*
|
|
* The pagetables are not updated but will presumably fault the page
|
|
* in if necessary, or if a kernel page the caller will at some point
|
|
* enter the page into the kernel's pmap. We are not allowed to block
|
|
* here so we *can't* do this anyway.
|
|
*
|
|
* The object and page must be locked, and must be splhigh.
|
|
* This routine may not block.
|
|
*/
|
|
|
|
void
|
|
vm_page_insert(m, object, pindex)
|
|
register vm_page_t m;
|
|
register vm_object_t object;
|
|
register vm_pindex_t pindex;
|
|
{
|
|
register struct vm_page **bucket;
|
|
|
|
if (m->object != NULL)
|
|
panic("vm_page_insert: already inserted");
|
|
|
|
/*
|
|
* 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)];
|
|
m->hnext = *bucket;
|
|
*bucket = m;
|
|
vm_page_bucket_generation++;
|
|
|
|
/*
|
|
* Now link into the object's list of backed pages.
|
|
*/
|
|
|
|
TAILQ_INSERT_TAIL(&object->memq, m, listq);
|
|
object->generation++;
|
|
|
|
/*
|
|
* show that the object has one more resident page.
|
|
*/
|
|
|
|
object->resident_page_count++;
|
|
|
|
/*
|
|
* Since we are inserting a new and possibly dirty page,
|
|
* update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
|
|
*/
|
|
if (m->flags & PG_WRITEABLE)
|
|
vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
|
|
}
|
|
|
|
/*
|
|
* vm_page_remove:
|
|
* NOTE: used by device pager as well -wfj
|
|
*
|
|
* Removes the given mem entry from the object/offset-page
|
|
* table and the object page list, but do not invalidate/terminate
|
|
* the backing store.
|
|
*
|
|
* The object and page must be locked, and at splhigh.
|
|
* The underlying pmap entry (if any) is NOT removed here.
|
|
* This routine may not block.
|
|
*/
|
|
|
|
void
|
|
vm_page_remove(m)
|
|
vm_page_t m;
|
|
{
|
|
vm_object_t object;
|
|
|
|
if (m->object == NULL)
|
|
return;
|
|
|
|
if ((m->flags & PG_BUSY) == 0) {
|
|
panic("vm_page_remove: page not busy");
|
|
}
|
|
|
|
/*
|
|
* Basically destroy the page.
|
|
*/
|
|
|
|
vm_page_wakeup(m);
|
|
|
|
object = m->object;
|
|
|
|
/*
|
|
* Remove from the object_object/offset hash table. The object
|
|
* must be on the hash queue, we will panic if it isn't
|
|
*
|
|
* Note: we must NULL-out m->hnext to prevent loops in detached
|
|
* buffers with vm_page_lookup().
|
|
*/
|
|
|
|
{
|
|
struct vm_page **bucket;
|
|
|
|
bucket = &vm_page_buckets[vm_page_hash(m->object, m->pindex)];
|
|
while (*bucket != m) {
|
|
if (*bucket == NULL)
|
|
panic("vm_page_remove(): page not found in hash");
|
|
bucket = &(*bucket)->hnext;
|
|
}
|
|
*bucket = m->hnext;
|
|
m->hnext = NULL;
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* vm_page_lookup:
|
|
*
|
|
* Returns the page associated with the object/offset
|
|
* pair specified; if none is found, NULL is returned.
|
|
*
|
|
* NOTE: the code below does not lock. It will operate properly if
|
|
* an interrupt makes a change, but the generation algorithm will not
|
|
* operate properly in an SMP environment where both cpu's are able to run
|
|
* kernel code simultaneously.
|
|
*
|
|
* The object must be locked. No side effects.
|
|
* This routine may not block.
|
|
* This is a critical path routine
|
|
*/
|
|
|
|
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 vm_page **bucket;
|
|
int generation;
|
|
|
|
/*
|
|
* Search the hash table for this object/offset pair
|
|
*/
|
|
|
|
retry:
|
|
generation = vm_page_bucket_generation;
|
|
bucket = &vm_page_buckets[vm_page_hash(object, pindex)];
|
|
for (m = *bucket; m != NULL; m = m->hnext) {
|
|
if ((m->object == object) && (m->pindex == pindex)) {
|
|
if (vm_page_bucket_generation != generation)
|
|
goto retry;
|
|
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.
|
|
* This routine may not block.
|
|
*
|
|
* Note: this routine will raise itself to splvm(), the caller need not.
|
|
*
|
|
* Note: swap associated with the page must be invalidated by the move. We
|
|
* have to do this for several reasons: (1) we aren't freeing the
|
|
* page, (2) we are dirtying the page, (3) the VM system is probably
|
|
* moving the page from object A to B, and will then later move
|
|
* the backing store from A to B and we can't have a conflict.
|
|
*
|
|
* Note: we *always* dirty the page. It is necessary both for the
|
|
* fact that we moved it, and because we may be invalidating
|
|
* swap. If the page is on the cache, we have to deactivate it
|
|
* or vm_page_dirty() will panic. Dirty pages are not allowed
|
|
* on the cache.
|
|
*/
|
|
|
|
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);
|
|
if (m->queue - m->pc == PQ_CACHE)
|
|
vm_page_deactivate(m);
|
|
vm_page_dirty(m);
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* vm_page_unqueue_nowakeup:
|
|
*
|
|
* vm_page_unqueue() without any wakeup
|
|
*
|
|
* This routine must be called at splhigh().
|
|
* This routine may not block.
|
|
*/
|
|
|
|
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--;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_page_unqueue:
|
|
*
|
|
* Remove a page from its queue.
|
|
*
|
|
* This routine must be called at splhigh().
|
|
* This routine may not block.
|
|
*/
|
|
|
|
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 (vm_paging_needed())
|
|
pagedaemon_wakeup();
|
|
}
|
|
}
|
|
}
|
|
|
|
#if PQ_L2_SIZE > 1
|
|
|
|
/*
|
|
* vm_page_list_find:
|
|
*
|
|
* Find a page on the specified queue with color optimization.
|
|
*
|
|
* The page coloring optimization attempts to locate a page
|
|
* that does not overload other nearby pages in the object in
|
|
* the cpu's L1 or L2 caches. We need this optimization because
|
|
* cpu caches tend to be physical caches, while object spaces tend
|
|
* to be virtual.
|
|
*
|
|
* This routine must be called at splvm().
|
|
* This routine may not block.
|
|
*
|
|
* This routine may only be called from the vm_page_list_find() macro
|
|
* in vm_page.h
|
|
*/
|
|
vm_page_t
|
|
_vm_page_list_find(basequeue, index)
|
|
int basequeue, index;
|
|
{
|
|
int i;
|
|
vm_page_t m = NULL;
|
|
struct vpgqueues *pq;
|
|
|
|
pq = &vm_page_queues[basequeue];
|
|
|
|
/*
|
|
* Note that for the first loop, index+i and index-i wind up at the
|
|
* same place. Even though this is not totally optimal, we've already
|
|
* blown it by missing the cache case so we do not care.
|
|
*/
|
|
|
|
for(i = PQ_L2_SIZE / 2; i > 0; --i) {
|
|
if ((m = TAILQ_FIRST(&pq[(index + i) & PQ_L2_MASK].pl)) != NULL)
|
|
break;
|
|
|
|
if ((m = TAILQ_FIRST(&pq[(index - i) & PQ_L2_MASK].pl)) != NULL)
|
|
break;
|
|
}
|
|
return(m);
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* vm_page_select_cache:
|
|
*
|
|
* 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.
|
|
*
|
|
* This routine must be called at splvm().
|
|
* This routine may not block.
|
|
*/
|
|
vm_page_t
|
|
vm_page_select_cache(object, pindex)
|
|
vm_object_t object;
|
|
vm_pindex_t pindex;
|
|
{
|
|
vm_page_t m;
|
|
|
|
while (TRUE) {
|
|
m = vm_page_list_find(
|
|
PQ_CACHE,
|
|
(pindex + object->pg_color) & PQ_L2_MASK,
|
|
FALSE
|
|
);
|
|
if (m && ((m->flags & PG_BUSY) || m->busy ||
|
|
m->hold_count || m->wire_count)) {
|
|
vm_page_deactivate(m);
|
|
continue;
|
|
}
|
|
return m;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_page_select_free:
|
|
*
|
|
* Find a free or zero page, with specified preference. We attempt to
|
|
* inline the nominal case and fall back to _vm_page_select_free()
|
|
* otherwise.
|
|
*
|
|
* This routine must be called at splvm().
|
|
* This routine may not block.
|
|
*/
|
|
|
|
static __inline vm_page_t
|
|
vm_page_select_free(vm_object_t object, vm_pindex_t pindex, boolean_t prefer_zero)
|
|
{
|
|
vm_page_t m;
|
|
|
|
m = vm_page_list_find(
|
|
PQ_FREE,
|
|
(pindex + object->pg_color) & PQ_L2_MASK,
|
|
prefer_zero
|
|
);
|
|
return(m);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
* This routine may not block.
|
|
*
|
|
* Additional special handling is required when called from an
|
|
* interrupt (VM_ALLOC_INTERRUPT). We are not allowed to mess with
|
|
* the page cache in this case.
|
|
*/
|
|
|
|
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 = NULL;
|
|
int s;
|
|
|
|
KASSERT(!vm_page_lookup(object, pindex),
|
|
("vm_page_alloc: page already allocated"));
|
|
|
|
/*
|
|
* The pager is allowed to eat deeper into the free page list.
|
|
*/
|
|
|
|
if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) {
|
|
page_req = VM_ALLOC_SYSTEM;
|
|
};
|
|
|
|
s = splvm();
|
|
|
|
loop:
|
|
if (cnt.v_free_count > cnt.v_free_reserved) {
|
|
/*
|
|
* Allocate from the free queue if there are plenty of pages
|
|
* in it.
|
|
*/
|
|
if (page_req == VM_ALLOC_ZERO)
|
|
m = vm_page_select_free(object, pindex, TRUE);
|
|
else
|
|
m = vm_page_select_free(object, pindex, FALSE);
|
|
} else if (
|
|
(page_req == VM_ALLOC_SYSTEM &&
|
|
cnt.v_cache_count == 0 &&
|
|
cnt.v_free_count > cnt.v_interrupt_free_min) ||
|
|
(page_req == VM_ALLOC_INTERRUPT && cnt.v_free_count > 0)
|
|
) {
|
|
/*
|
|
* Interrupt or system, dig deeper into the free list.
|
|
*/
|
|
m = vm_page_select_free(object, pindex, FALSE);
|
|
} else if (page_req != VM_ALLOC_INTERRUPT) {
|
|
/*
|
|
* Allocatable from cache (non-interrupt only). On success,
|
|
* we must free the page and try again, thus ensuring that
|
|
* cnt.v_*_free_min counters are replenished.
|
|
*/
|
|
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);
|
|
}
|
|
KASSERT(m->dirty == 0, ("Found dirty cache page %p", m));
|
|
vm_page_busy(m);
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
vm_page_free(m);
|
|
goto loop;
|
|
} else {
|
|
/*
|
|
* Not allocatable from cache from interrupt, give up.
|
|
*/
|
|
splx(s);
|
|
vm_pageout_deficit++;
|
|
pagedaemon_wakeup();
|
|
return (NULL);
|
|
}
|
|
|
|
/*
|
|
* At this point we had better have found a good page.
|
|
*/
|
|
|
|
KASSERT(
|
|
m != NULL,
|
|
("vm_page_alloc(): missing page on free queue\n")
|
|
);
|
|
|
|
/*
|
|
* Remove from free queue
|
|
*/
|
|
|
|
vm_page_unqueue_nowakeup(m);
|
|
|
|
/*
|
|
* Initialize structure. Only the PG_ZERO flag is inherited.
|
|
*/
|
|
|
|
if (m->flags & PG_ZERO) {
|
|
vm_page_zero_count--;
|
|
m->flags = PG_ZERO | 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;
|
|
KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m));
|
|
|
|
/*
|
|
* vm_page_insert() is safe prior to the splx(). Note also that
|
|
* inserting a page here does not insert it into the pmap (which
|
|
* could cause us to block allocating memory). We cannot block
|
|
* anywhere.
|
|
*/
|
|
|
|
vm_page_insert(m, object, pindex);
|
|
|
|
/*
|
|
* Don't wakeup too often - wakeup the pageout daemon when
|
|
* we would be nearly out of memory.
|
|
*/
|
|
if (vm_paging_needed() || cnt.v_free_count < cnt.v_pageout_free_min)
|
|
pagedaemon_wakeup();
|
|
|
|
splx(s);
|
|
|
|
return (m);
|
|
}
|
|
|
|
/*
|
|
* vm_wait: (also see VM_WAIT macro)
|
|
*
|
|
* Block until free pages are available for allocation
|
|
*/
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* vm_await: (also see VM_AWAIT macro)
|
|
*
|
|
* asleep on an event that will signal when free pages are available
|
|
* for allocation.
|
|
*/
|
|
|
|
void
|
|
vm_await()
|
|
{
|
|
int s;
|
|
|
|
s = splvm();
|
|
if (curproc == pageproc) {
|
|
vm_pageout_pages_needed = 1;
|
|
asleep(&vm_pageout_pages_needed, PSWP, "vmwait", 0);
|
|
} else {
|
|
if (!vm_pages_needed) {
|
|
vm_pages_needed++;
|
|
wakeup(&vm_pages_needed);
|
|
}
|
|
asleep(&cnt.v_free_count, PVM, "vmwait", 0);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
#if 0
|
|
/*
|
|
* vm_page_sleep:
|
|
*
|
|
* Block until page is no longer busy.
|
|
*/
|
|
|
|
int
|
|
vm_page_sleep(vm_page_t m, char *msg, char *busy) {
|
|
int slept = 0;
|
|
if ((busy && *busy) || (m->flags & PG_BUSY)) {
|
|
int s;
|
|
s = splvm();
|
|
if ((busy && *busy) || (m->flags & PG_BUSY)) {
|
|
vm_page_flag_set(m, PG_WANTED);
|
|
tsleep(m, PVM, msg, 0);
|
|
slept = 1;
|
|
}
|
|
splx(s);
|
|
}
|
|
return slept;
|
|
}
|
|
|
|
#endif
|
|
|
|
#if 0
|
|
|
|
/*
|
|
* vm_page_asleep:
|
|
*
|
|
* Similar to vm_page_sleep(), but does not block. Returns 0 if
|
|
* the page is not busy, or 1 if the page is busy.
|
|
*
|
|
* This routine has the side effect of calling asleep() if the page
|
|
* was busy (1 returned).
|
|
*/
|
|
|
|
int
|
|
vm_page_asleep(vm_page_t m, char *msg, char *busy) {
|
|
int slept = 0;
|
|
if ((busy && *busy) || (m->flags & PG_BUSY)) {
|
|
int s;
|
|
s = splvm();
|
|
if ((busy && *busy) || (m->flags & PG_BUSY)) {
|
|
vm_page_flag_set(m, PG_WANTED);
|
|
asleep(m, PVM, msg, 0);
|
|
slept = 1;
|
|
}
|
|
splx(s);
|
|
}
|
|
return slept;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* vm_page_activate:
|
|
*
|
|
* Put the specified page on the active list (if appropriate).
|
|
* Ensure that act_count is at least ACT_INIT but do not otherwise
|
|
* mess with it.
|
|
*
|
|
* The page queues must be locked.
|
|
* This routine may not block.
|
|
*/
|
|
void
|
|
vm_page_activate(m)
|
|
register vm_page_t m;
|
|
{
|
|
int s;
|
|
|
|
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_queues[PQ_ACTIVE].pl, 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);
|
|
}
|
|
|
|
/*
|
|
* vm_page_free_wakeup:
|
|
*
|
|
* Helper routine for vm_page_free_toq() and vm_page_cache(). This
|
|
* routine is called when a page has been added to the cache or free
|
|
* queues.
|
|
*
|
|
* This routine may not block.
|
|
* This routine must be called at splvm()
|
|
*/
|
|
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 && vm_page_count_min()) {
|
|
wakeup(&cnt.v_free_count);
|
|
vm_pages_needed = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_page_free_toq:
|
|
*
|
|
* Returns the given page to the PQ_FREE list,
|
|
* disassociating it with any VM object.
|
|
*
|
|
* Object and page must be locked prior to entry.
|
|
* This routine may not block.
|
|
*/
|
|
|
|
void
|
|
vm_page_free_toq(vm_page_t m)
|
|
{
|
|
int s;
|
|
struct vpgqueues *pq;
|
|
vm_object_t object = m->object;
|
|
|
|
s = splvm();
|
|
|
|
cnt.v_tfree++;
|
|
|
|
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");
|
|
}
|
|
|
|
/*
|
|
* unqueue, then remove page. Note that we cannot destroy
|
|
* the page here because we do not want to call the pager's
|
|
* callback routine until after we've put the page on the
|
|
* appropriate free queue.
|
|
*/
|
|
|
|
vm_page_unqueue_nowakeup(m);
|
|
vm_page_remove(m);
|
|
|
|
/*
|
|
* If fictitious remove object association and
|
|
* return, otherwise delay object association removal.
|
|
*/
|
|
|
|
if ((m->flags & PG_FICTITIOUS) != 0) {
|
|
splx(s);
|
|
return;
|
|
}
|
|
|
|
m->valid = 0;
|
|
vm_page_undirty(m);
|
|
|
|
if (m->wire_count != 0) {
|
|
if (m->wire_count > 1) {
|
|
panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx",
|
|
m->wire_count, (long)m->pindex);
|
|
}
|
|
panic("vm_page_free: freeing wired page\n");
|
|
}
|
|
|
|
/*
|
|
* If we've exhausted the object's resident pages we want to free
|
|
* it up.
|
|
*/
|
|
|
|
if (object &&
|
|
(object->type == OBJT_VNODE) &&
|
|
((object->flags & OBJ_DEAD) == 0)
|
|
) {
|
|
struct vnode *vp = (struct vnode *)object->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;
|
|
}
|
|
}
|
|
}
|
|
|
|
#ifdef __alpha__
|
|
pmap_page_is_free(m);
|
|
#endif
|
|
|
|
m->queue = PQ_FREE + m->pc;
|
|
pq = &vm_page_queues[m->queue];
|
|
pq->lcnt++;
|
|
++(*pq->cnt);
|
|
|
|
/*
|
|
* Put zero'd pages on the end ( where we look for zero'd pages
|
|
* first ) and non-zerod pages at the head.
|
|
*/
|
|
|
|
if (m->flags & PG_ZERO) {
|
|
TAILQ_INSERT_TAIL(&pq->pl, m, pageq);
|
|
++vm_page_zero_count;
|
|
} else {
|
|
TAILQ_INSERT_HEAD(&pq->pl, m, pageq);
|
|
}
|
|
|
|
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.
|
|
* This routine may not block.
|
|
*/
|
|
void
|
|
vm_page_wire(m)
|
|
register vm_page_t m;
|
|
{
|
|
int s;
|
|
|
|
s = splvm();
|
|
if (m->wire_count == 0) {
|
|
vm_page_unqueue(m);
|
|
cnt.v_wire_count++;
|
|
}
|
|
m->wire_count++;
|
|
splx(s);
|
|
vm_page_flag_set(m, PG_MAPPED);
|
|
}
|
|
|
|
/*
|
|
* vm_page_unwire:
|
|
*
|
|
* Release one wiring of this page, potentially
|
|
* enabling it to be paged again.
|
|
*
|
|
* Many pages placed on the inactive queue should actually go
|
|
* into the cache, but it is difficult to figure out which. What
|
|
* we do instead, if the inactive target is well met, is to put
|
|
* clean pages at the head of the inactive queue instead of the tail.
|
|
* This will cause them to be moved to the cache more quickly and
|
|
* if not actively re-referenced, freed more quickly. If we just
|
|
* stick these pages at the end of the inactive queue, heavy filesystem
|
|
* meta-data accesses can cause an unnecessary paging load on memory bound
|
|
* processes. This optimization causes one-time-use metadata to be
|
|
* reused more quickly.
|
|
*
|
|
* A number of routines use vm_page_unwire() to guarantee that the page
|
|
* will go into either the inactive or active queues, and will NEVER
|
|
* be placed in the cache - for example, just after dirtying a page.
|
|
* dirty pages in the cache are not allowed.
|
|
*
|
|
* The page queues must be locked.
|
|
* This routine may not block.
|
|
*/
|
|
void
|
|
vm_page_unwire(m, activate)
|
|
register vm_page_t m;
|
|
int activate;
|
|
{
|
|
int s;
|
|
|
|
s = splvm();
|
|
|
|
if (m->wire_count > 0) {
|
|
m->wire_count--;
|
|
if (m->wire_count == 0) {
|
|
cnt.v_wire_count--;
|
|
if (activate) {
|
|
TAILQ_INSERT_TAIL(&vm_page_queues[PQ_ACTIVE].pl, m, pageq);
|
|
m->queue = PQ_ACTIVE;
|
|
vm_page_queues[PQ_ACTIVE].lcnt++;
|
|
cnt.v_active_count++;
|
|
} else {
|
|
TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq);
|
|
m->queue = PQ_INACTIVE;
|
|
vm_page_queues[PQ_INACTIVE].lcnt++;
|
|
cnt.v_inactive_count++;
|
|
}
|
|
}
|
|
} else {
|
|
panic("vm_page_unwire: invalid wire count: %d\n", m->wire_count);
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
|
|
/*
|
|
* Move the specified page to the inactive queue. If the page has
|
|
* any associated swap, the swap is deallocated.
|
|
*
|
|
* Normally athead is 0 resulting in LRU operation. athead is set
|
|
* to 1 if we want this page to be 'as if it were placed in the cache',
|
|
* except without unmapping it from the process address space.
|
|
*
|
|
* This routine may not block.
|
|
*/
|
|
static __inline void
|
|
_vm_page_deactivate(vm_page_t m, int athead)
|
|
{
|
|
int s;
|
|
|
|
/*
|
|
* Ignore if already inactive.
|
|
*/
|
|
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);
|
|
if (athead)
|
|
TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, pageq);
|
|
else
|
|
TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq);
|
|
m->queue = PQ_INACTIVE;
|
|
vm_page_queues[PQ_INACTIVE].lcnt++;
|
|
cnt.v_inactive_count++;
|
|
}
|
|
splx(s);
|
|
}
|
|
|
|
void
|
|
vm_page_deactivate(vm_page_t m)
|
|
{
|
|
_vm_page_deactivate(m, 0);
|
|
}
|
|
|
|
/*
|
|
* vm_page_cache
|
|
*
|
|
* Put the specified page onto the page cache queue (if appropriate).
|
|
*
|
|
* This routine may not block.
|
|
*/
|
|
void
|
|
vm_page_cache(m)
|
|
register vm_page_t m;
|
|
{
|
|
int s;
|
|
|
|
if ((m->flags & PG_BUSY) || m->busy || m->wire_count) {
|
|
printf("vm_page_cache: attempting to cache busy page\n");
|
|
return;
|
|
}
|
|
if ((m->queue - m->pc) == PQ_CACHE)
|
|
return;
|
|
|
|
/*
|
|
* Remove all pmaps and indicate that the page is not
|
|
* writeable or mapped.
|
|
*/
|
|
|
|
vm_page_protect(m, VM_PROT_NONE);
|
|
if (m->dirty != 0) {
|
|
panic("vm_page_cache: caching a dirty page, pindex: %ld",
|
|
(long)m->pindex);
|
|
}
|
|
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++;
|
|
vm_page_free_wakeup();
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* vm_page_dontneed
|
|
*
|
|
* Cache, deactivate, or do nothing as appropriate. This routine
|
|
* is typically used by madvise() MADV_DONTNEED.
|
|
*
|
|
* Generally speaking we want to move the page into the cache so
|
|
* it gets reused quickly. However, this can result in a silly syndrome
|
|
* due to the page recycling too quickly. Small objects will not be
|
|
* fully cached. On the otherhand, if we move the page to the inactive
|
|
* queue we wind up with a problem whereby very large objects
|
|
* unnecessarily blow away our inactive and cache queues.
|
|
*
|
|
* The solution is to move the pages based on a fixed weighting. We
|
|
* either leave them alone, deactivate them, or move them to the cache,
|
|
* where moving them to the cache has the highest weighting.
|
|
* By forcing some pages into other queues we eventually force the
|
|
* system to balance the queues, potentially recovering other unrelated
|
|
* space from active. The idea is to not force this to happen too
|
|
* often.
|
|
*/
|
|
|
|
void
|
|
vm_page_dontneed(m)
|
|
vm_page_t m;
|
|
{
|
|
static int dnweight;
|
|
int dnw;
|
|
int head;
|
|
|
|
dnw = ++dnweight;
|
|
|
|
/*
|
|
* occassionally leave the page alone
|
|
*/
|
|
|
|
if ((dnw & 0x01F0) == 0 ||
|
|
m->queue == PQ_INACTIVE ||
|
|
m->queue - m->pc == PQ_CACHE
|
|
) {
|
|
if (m->act_count >= ACT_INIT)
|
|
--m->act_count;
|
|
return;
|
|
}
|
|
|
|
if (m->dirty == 0)
|
|
vm_page_test_dirty(m);
|
|
|
|
if (m->dirty || (dnw & 0x0070) == 0) {
|
|
/*
|
|
* Deactivate the page 3 times out of 32.
|
|
*/
|
|
head = 0;
|
|
} else {
|
|
/*
|
|
* Cache the page 28 times out of every 32. Note that
|
|
* the page is deactivated instead of cached, but placed
|
|
* at the head of the queue instead of the tail.
|
|
*/
|
|
head = 1;
|
|
}
|
|
_vm_page_deactivate(m, head);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* This routine may block.
|
|
*/
|
|
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))) {
|
|
vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
|
|
tsleep(m, PVM, "pgrbwt", 0);
|
|
if ((allocflags & VM_ALLOC_RETRY) == 0) {
|
|
splx(s);
|
|
return NULL;
|
|
}
|
|
}
|
|
splx(s);
|
|
goto retrylookup;
|
|
} else {
|
|
vm_page_busy(m);
|
|
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. May not block.
|
|
*
|
|
* Inputs are required to range within a page.
|
|
*/
|
|
|
|
__inline int
|
|
vm_page_bits(int base, int size)
|
|
{
|
|
int first_bit;
|
|
int last_bit;
|
|
|
|
KASSERT(
|
|
base + size <= PAGE_SIZE,
|
|
("vm_page_bits: illegal base/size %d/%d", base, size)
|
|
);
|
|
|
|
if (size == 0) /* handle degenerate case */
|
|
return(0);
|
|
|
|
first_bit = base >> DEV_BSHIFT;
|
|
last_bit = (base + size - 1) >> DEV_BSHIFT;
|
|
|
|
return ((2 << last_bit) - (1 << first_bit));
|
|
}
|
|
|
|
/*
|
|
* vm_page_set_validclean:
|
|
*
|
|
* Sets portions of a page valid and clean. The arguments are expected
|
|
* to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
|
|
* of any partial chunks touched by the range. The invalid portion of
|
|
* such chunks will be zero'd.
|
|
*
|
|
* This routine may not block.
|
|
*
|
|
* (base + size) must be less then or equal to PAGE_SIZE.
|
|
*/
|
|
void
|
|
vm_page_set_validclean(m, base, size)
|
|
vm_page_t m;
|
|
int base;
|
|
int size;
|
|
{
|
|
int pagebits;
|
|
int frag;
|
|
int endoff;
|
|
|
|
if (size == 0) /* handle degenerate case */
|
|
return;
|
|
|
|
/*
|
|
* If the base is not DEV_BSIZE aligned and the valid
|
|
* bit is clear, we have to zero out a portion of the
|
|
* first block.
|
|
*/
|
|
|
|
if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
|
|
(m->valid & (1 << (base >> DEV_BSHIFT))) == 0
|
|
) {
|
|
pmap_zero_page_area(
|
|
VM_PAGE_TO_PHYS(m),
|
|
frag,
|
|
base - frag
|
|
);
|
|
}
|
|
|
|
/*
|
|
* If the ending offset is not DEV_BSIZE aligned and the
|
|
* valid bit is clear, we have to zero out a portion of
|
|
* the last block.
|
|
*/
|
|
|
|
endoff = base + size;
|
|
|
|
if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
|
|
(m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0
|
|
) {
|
|
pmap_zero_page_area(
|
|
VM_PAGE_TO_PHYS(m),
|
|
endoff,
|
|
DEV_BSIZE - (endoff & (DEV_BSIZE - 1))
|
|
);
|
|
}
|
|
|
|
/*
|
|
* Set valid, clear dirty bits. If validating the entire
|
|
* page we can safely clear the pmap modify bit. We also
|
|
* use this opportunity to clear the PG_NOSYNC flag. If a process
|
|
* takes a write fault on a MAP_NOSYNC memory area the flag will
|
|
* be set again.
|
|
*/
|
|
|
|
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));
|
|
vm_page_flag_clear(m, PG_NOSYNC);
|
|
}
|
|
}
|
|
|
|
#if 0
|
|
|
|
void
|
|
vm_page_set_dirty(m, base, size)
|
|
vm_page_t m;
|
|
int base;
|
|
int size;
|
|
{
|
|
m->dirty |= vm_page_bits(base, size);
|
|
}
|
|
|
|
#endif
|
|
|
|
void
|
|
vm_page_clear_dirty(m, base, size)
|
|
vm_page_t m;
|
|
int base;
|
|
int size;
|
|
{
|
|
m->dirty &= ~vm_page_bits(base, size);
|
|
}
|
|
|
|
/*
|
|
* vm_page_set_invalid:
|
|
*
|
|
* Invalidates DEV_BSIZE'd chunks within a page. Both the
|
|
* valid and dirty bits for the effected areas are cleared.
|
|
*
|
|
* May not block.
|
|
*/
|
|
void
|
|
vm_page_set_invalid(m, base, size)
|
|
vm_page_t m;
|
|
int base;
|
|
int size;
|
|
{
|
|
int bits;
|
|
|
|
bits = vm_page_bits(base, size);
|
|
m->valid &= ~bits;
|
|
m->dirty &= ~bits;
|
|
m->object->generation++;
|
|
}
|
|
|
|
/*
|
|
* vm_page_zero_invalid()
|
|
*
|
|
* The kernel assumes that the invalid portions of a page contain
|
|
* garbage, but such pages can be mapped into memory by user code.
|
|
* When this occurs, we must zero out the non-valid portions of the
|
|
* page so user code sees what it expects.
|
|
*
|
|
* Pages are most often semi-valid when the end of a file is mapped
|
|
* into memory and the file's size is not page aligned.
|
|
*/
|
|
|
|
void
|
|
vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
|
|
{
|
|
int b;
|
|
int i;
|
|
|
|
/*
|
|
* Scan the valid bits looking for invalid sections that
|
|
* must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
|
|
* valid bit may be set ) have already been zerod by
|
|
* vm_page_set_validclean().
|
|
*/
|
|
|
|
for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
|
|
if (i == (PAGE_SIZE / DEV_BSIZE) ||
|
|
(m->valid & (1 << i))
|
|
) {
|
|
if (i > b) {
|
|
pmap_zero_page_area(
|
|
VM_PAGE_TO_PHYS(m),
|
|
b << DEV_BSHIFT,
|
|
(i - b) << DEV_BSHIFT
|
|
);
|
|
}
|
|
b = i + 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* setvalid is TRUE when we can safely set the zero'd areas
|
|
* as being valid. We can do this if there are no cache consistancy
|
|
* issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
|
|
*/
|
|
|
|
if (setvalid)
|
|
m->valid = VM_PAGE_BITS_ALL;
|
|
}
|
|
|
|
/*
|
|
* vm_page_is_valid:
|
|
*
|
|
* Is (partial) page valid? Note that the case where size == 0
|
|
* will return FALSE in the degenerate case where the page is
|
|
* entirely invalid, and TRUE otherwise.
|
|
*
|
|
* May not block.
|
|
*/
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* update dirty bits from pmap/mmu. May not block.
|
|
*/
|
|
|
|
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))) {
|
|
vm_page_dirty(m);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 (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");
|
|
|
|
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_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_queues[PQ_INACTIVE].pl);
|
|
m != NULL;
|
|
m = next) {
|
|
|
|
KASSERT(m->queue == PQ_INACTIVE,
|
|
("contigmalloc1: page %p is not PQ_INACTIVE", m));
|
|
|
|
next = TAILQ_NEXT(m, pageq);
|
|
if (vm_page_sleep_busy(m, TRUE, "vpctw0"))
|
|
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_queues[PQ_ACTIVE].pl);
|
|
m != NULL;
|
|
m = next) {
|
|
|
|
KASSERT(m->queue == PQ_ACTIVE,
|
|
("contigmalloc1: page %p is not PQ_ACTIVE", m));
|
|
|
|
next = TAILQ_NEXT(m, pageq);
|
|
if (vm_page_sleep_busy(m, TRUE, "vpctw1"))
|
|
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_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) {
|
|
vm_page_busy(m);
|
|
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;
|
|
KASSERT(m->dirty == 0, ("contigmalloc1: page %p was dirty", m));
|
|
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);
|
|
}
|
|
|
|
void
|
|
contigfree(addr, size, type)
|
|
void *addr;
|
|
unsigned long size;
|
|
struct malloc_type *type;
|
|
{
|
|
kmem_free(kernel_map, (vm_offset_t)addr, size);
|
|
}
|
|
|
|
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_ACTIVE: %d, PQ_INACTIVE: %d\n",
|
|
vm_page_queues[PQ_ACTIVE].lcnt,
|
|
vm_page_queues[PQ_INACTIVE].lcnt);
|
|
}
|
|
#endif /* DDB */
|