FreeBSD-5.3/sys/vm/vm_contig.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.
* 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
*/
/*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/vm/vm_contig.c,v 1.38 2004/08/05 21:54:11 green Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/linker_set.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <vm/vm_map.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 int
vm_contig_launder_page(vm_page_t m)
{
vm_object_t object;
vm_page_t m_tmp;
struct vnode *vp;
if (vm_page_sleep_if_busy(m, TRUE, "vpctw0")) {
vm_page_lock_queues();
return (EBUSY);
}
if (!VM_OBJECT_TRYLOCK(m->object))
return (EAGAIN);
vm_page_test_dirty(m);
if (m->dirty == 0 && m->hold_count == 0)
pmap_remove_all(m);
if (m->dirty) {
object = m->object;
if (object->type == OBJT_VNODE) {
vm_page_unlock_queues();
vp = object->handle;
VM_OBJECT_UNLOCK(object);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
VM_OBJECT_LOCK(object);
vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
VM_OBJECT_UNLOCK(object);
VOP_UNLOCK(vp, 0, curthread);
vm_page_lock_queues();
return (0);
} else if (object->type == OBJT_SWAP ||
object->type == OBJT_DEFAULT) {
m_tmp = m;
vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC);
VM_OBJECT_UNLOCK(object);
return (0);
}
} else if (m->hold_count == 0)
vm_page_cache(m);
VM_OBJECT_UNLOCK(m->object);
return (0);
}
static int
vm_contig_launder(int queue)
{
vm_page_t m, next;
int error;
for (m = TAILQ_FIRST(&vm_page_queues[queue].pl); m != NULL; m = next) {
next = TAILQ_NEXT(m, pageq);
KASSERT(m->queue == queue,
("vm_contig_launder: page %p's queue is not %d", m, queue));
error = vm_contig_launder_page(m);
if (error == 0)
return (TRUE);
if (error == EBUSY)
return (FALSE);
}
return (FALSE);
}
/*
* 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.
*/
static void *
contigmalloc1(
unsigned long size, /* should be size_t here and for malloc() */
struct malloc_type *type,
int flags,
vm_paddr_t low,
vm_paddr_t high,
unsigned long alignment,
unsigned long boundary,
vm_map_t map)
{
int i, start;
vm_paddr_t phys;
vm_object_t object;
vm_offset_t addr, tmp_addr;
int pass, pqtype;
int inactl, actl, inactmax, actmax;
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 = 2; pass >= 0; pass--) {
vm_page_lock_queues();
again0:
mtx_lock_spin(&vm_page_queue_free_mtx);
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++) {
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)) {
mtx_unlock_spin(&vm_page_queue_free_mtx);
/*
* Instead of racing to empty the inactive/active
* queues, give up, even with more left to free,
* if we try more than the initial amount of pages.
*
* There's no point attempting this on the last pass.
*/
if (pass > 0) {
inactl = actl = 0;
inactmax = vm_page_queues[PQ_INACTIVE].lcnt;
actmax = vm_page_queues[PQ_ACTIVE].lcnt;
again1:
if (inactl < inactmax &&
vm_contig_launder(PQ_INACTIVE)) {
inactl++;
goto again1;
}
if (actl < actmax &&
vm_contig_launder(PQ_ACTIVE)) {
actl++;
goto again1;
}
}
vm_page_unlock_queues();
continue;
}
start = i;
/*
* Check successive pages for contiguous and free.
*/
for (i = start + 1; i < (start + size / PAGE_SIZE); i++) {
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;
}
}
mtx_unlock_spin(&vm_page_queue_free_mtx);
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
if ((m->queue - m->pc) == PQ_CACHE) {
object = m->object;
if (!VM_OBJECT_TRYLOCK(object)) {
start++;
goto again0;
}
vm_page_busy(m);
vm_page_free(m);
VM_OBJECT_UNLOCK(object);
}
}
mtx_lock_spin(&vm_page_queue_free_mtx);
for (i = start; i < (start + size / PAGE_SIZE); i++) {
pqtype = pga[i].queue - pga[i].pc;
if (pqtype != PQ_FREE) {
start++;
goto again;
}
}
for (i = start; i < (start + size / PAGE_SIZE); i++) {
vm_page_t m = &pga[i];
vm_pageq_remove_nowakeup(m);
m->valid = VM_PAGE_BITS_ALL;
if (m->flags & PG_ZERO)
vm_page_zero_count--;
/* Don't clear the PG_ZERO flag, we'll need it later. */
m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
KASSERT(m->dirty == 0,
("contigmalloc1: page %p was dirty", m));
m->wire_count = 0;
m->busy = 0;
m->object = NULL;
}
mtx_unlock_spin(&vm_page_queue_free_mtx);
vm_page_unlock_queues();
/*
* 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.
*/
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr) !=
KERN_SUCCESS) {
/*
* XXX We almost never run out of kernel virtual
* space, so we don't make the allocated memory
* above available.
*/
vm_map_unlock(map);
return (NULL);
}
vm_object_reference(kernel_object);
vm_map_insert(map, kernel_object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
vm_map_unlock(map);
tmp_addr = addr;
VM_OBJECT_LOCK(kernel_object);
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));
if ((flags & M_ZERO) && !(m->flags & PG_ZERO))
pmap_zero_page(m);
tmp_addr += PAGE_SIZE;
}
VM_OBJECT_UNLOCK(kernel_object);
vm_map_wire(map, addr, addr + size,
VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
return ((void *)addr);
}
return (NULL);
}
static void
vm_page_release_contigl(vm_page_t m, vm_pindex_t count)
{
while (count--) {
vm_page_free_toq(m);
m++;
}
}
void
vm_page_release_contig(vm_page_t m, vm_pindex_t count)
{
vm_page_lock_queues();
vm_page_release_contigl(m, count);
vm_page_unlock_queues();
}
static int
vm_contig_unqueue_free(vm_page_t m)
{
int error = 0;
mtx_lock_spin(&vm_page_queue_free_mtx);
if ((m->queue - m->pc) == PQ_FREE)
vm_pageq_remove_nowakeup(m);
else
error = EAGAIN;
mtx_unlock_spin(&vm_page_queue_free_mtx);
if (error)
return (error);
m->valid = VM_PAGE_BITS_ALL;
if (m->flags & PG_ZERO)
vm_page_zero_count--;
/* Don't clear the PG_ZERO flag; we'll need it later. */
m->flags = PG_UNMANAGED | (m->flags & PG_ZERO);
KASSERT(m->dirty == 0,
("contigmalloc2: page %p was dirty", m));
m->wire_count = 0;
m->busy = 0;
m->object = NULL;
return (error);
}
vm_page_t
vm_page_alloc_contig(vm_pindex_t npages, vm_paddr_t low, vm_paddr_t high,
vm_offset_t alignment, vm_offset_t boundary)
{
vm_object_t object;
vm_offset_t size;
vm_paddr_t phys;
vm_page_t pga = vm_page_array;
int i, pass, pqtype, start;
size = npages << PAGE_SHIFT;
if (size == 0)
panic("vm_page_alloc_contig: size must not be 0");
if ((alignment & (alignment - 1)) != 0)
panic("vm_page_alloc_contig: alignment must be a power of 2");
if ((boundary & (boundary - 1)) != 0)
panic("vm_page_alloc_contig: boundary must be a power of 2");
for (pass = 0; pass < 2; pass++) {
start = vm_page_array_size;
vm_page_lock_queues();
retry:
start--;
/*
* Find last page in array that is free, within range,
* aligned, and such that the boundary won't be crossed.
*/
for (i = start; i >= 0; i--) {
phys = VM_PAGE_TO_PHYS(&pga[i]);
pqtype = pga[i].queue - pga[i].pc;
if (pass == 0) {
if (pqtype != PQ_FREE && pqtype != PQ_CACHE)
continue;
} else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
pga[i].queue != PQ_ACTIVE &&
pga[i].queue != PQ_INACTIVE)
continue;
if (phys >= low && phys + size <= high &&
((phys & (alignment - 1)) == 0) &&
((phys ^ (phys + size - 1)) & ~(boundary - 1)) == 0)
break;
}
/* There are no candidates at all. */
if (i == -1) {
vm_page_unlock_queues();
continue;
}
start = i;
/*
* Check successive pages for contiguous and free.
*/
for (i = start + 1; i < start + npages; i++) {
pqtype = pga[i].queue - pga[i].pc;
if (VM_PAGE_TO_PHYS(&pga[i]) !=
VM_PAGE_TO_PHYS(&pga[i - 1]) + PAGE_SIZE)
goto retry;
if (pass == 0) {
if (pqtype != PQ_FREE && pqtype != PQ_CACHE)
goto retry;
} else if (pqtype != PQ_FREE && pqtype != PQ_CACHE &&
pga[i].queue != PQ_ACTIVE &&
pga[i].queue != PQ_INACTIVE)
goto retry;
}
for (i = start; i < start + npages; i++) {
vm_page_t m = &pga[i];
retry_page:
pqtype = m->queue - m->pc;
if (pass != 0 && pqtype != PQ_FREE &&
pqtype != PQ_CACHE) {
switch (m->queue) {
case PQ_ACTIVE:
case PQ_INACTIVE:
if (vm_contig_launder_page(m) != 0)
goto cleanup_freed;
pqtype = m->queue - m->pc;
if (pqtype == PQ_FREE ||
pqtype == PQ_CACHE)
break;
default:
cleanup_freed:
vm_page_release_contigl(&pga[start],
i - start);
goto retry;
}
}
if (pqtype == PQ_CACHE) {
object = m->object;
if (!VM_OBJECT_TRYLOCK(object))
goto retry;
vm_page_busy(m);
vm_page_free(m);
VM_OBJECT_UNLOCK(object);
}
/*
* There is no good API for freeing a page
* directly to PQ_NONE on our behalf, so spin.
*/
if (vm_contig_unqueue_free(m) != 0)
goto retry_page;
}
vm_page_unlock_queues();
/*
* We've found a contiguous chunk that meets are requirements.
*/
return (&pga[start]);
}
return (NULL);
}
static void *
contigmalloc2(vm_page_t m, vm_pindex_t npages, int flags)
{
vm_object_t object = kernel_object;
vm_map_t map = kernel_map;
vm_offset_t addr, tmp_addr;
vm_pindex_t i;
/*
* Allocate kernel VM, unfree and assign the physical pages to
* it and return kernel VM pointer.
*/
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), npages << PAGE_SHIFT, &addr)
!= KERN_SUCCESS) {
vm_map_unlock(map);
return (NULL);
}
vm_object_reference(object);
vm_map_insert(map, object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + (npages << PAGE_SHIFT), VM_PROT_ALL, VM_PROT_ALL, 0);
vm_map_unlock(map);
tmp_addr = addr;
VM_OBJECT_LOCK(object);
for (i = 0; i < npages; i++) {
vm_page_insert(&m[i], object,
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
if ((flags & M_ZERO) && !(m->flags & PG_ZERO))
pmap_zero_page(&m[i]);
tmp_addr += PAGE_SIZE;
}
VM_OBJECT_UNLOCK(object);
vm_map_wire(map, addr, addr + (npages << PAGE_SHIFT),
VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
return ((void *)addr);
}
static int vm_old_contigmalloc = 0;
SYSCTL_INT(_vm, OID_AUTO, old_contigmalloc,
CTLFLAG_RW, &vm_old_contigmalloc, 0, "Use the old contigmalloc algorithm");
TUNABLE_INT("vm.old_contigmalloc", &vm_old_contigmalloc);
void *
contigmalloc(
unsigned long size, /* should be size_t here and for malloc() */
struct malloc_type *type,
int flags,
vm_paddr_t low,
vm_paddr_t high,
unsigned long alignment,
unsigned long boundary)
{
void * ret;
vm_page_t pages;
vm_pindex_t npgs;
npgs = round_page(size) >> PAGE_SHIFT;
mtx_lock(&Giant);
if (vm_old_contigmalloc) {
ret = contigmalloc1(size, type, flags, low, high, alignment,
boundary, kernel_map);
} else {
pages = vm_page_alloc_contig(npgs, low, high,
alignment, boundary);
if (pages == NULL) {
ret = NULL;
} else {
ret = contigmalloc2(pages, npgs, flags);
if (ret == NULL)
vm_page_release_contig(pages, npgs);
}
}
mtx_unlock(&Giant);
malloc_type_allocated(type, ret == NULL ? 0 : npgs << PAGE_SHIFT);
return (ret);
}
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
vm_pindex_t npgs;
npgs = round_page(size) >> PAGE_SHIFT;
kmem_free(kernel_map, (vm_offset_t)addr, size);
malloc_type_freed(type, npgs << PAGE_SHIFT);
}