freebsd-dev/sys/vm/vm_contig.c
Jayachandran C. 17dca144a2 Make vm_contig_grow_cache() extern, and use it when vm_phys_alloc_contig()
fails to allocate MIPS page table pages.  The current usage of VM_WAIT in
case of vm_phys_alloc_contig() failure is not correct, because:

"There is no guarantee that any of the available free (or cached) pages
after the VM_WAIT will fall within the range of suitable physical
addresses.  Every time this function sleeps and a single page is freed
(or cached) by someone else, this function will be reawakened.  With
a little bad luck, you could spin indefinitely."

We also add low and high parameters to vm_contig_grow_cache() and
vm_contig_launder() so that we restrict vm_contig_launder() to the range
of pages we are interested in.

Reported by: alc

Reviewed by:	alc
Approved by:	rrs (mentor)
2010-06-04 06:35:36 +00:00

394 lines
11 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.
* 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.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_phys.h>
#include <vm/vm_extern.h>
static int
vm_contig_launder_page(vm_page_t m, vm_page_t *next)
{
vm_object_t object;
vm_page_t m_tmp;
struct vnode *vp;
struct mount *mp;
int vfslocked;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
vm_page_lock_assert(m, MA_OWNED);
object = m->object;
if (!VM_OBJECT_TRYLOCK(object) &&
!vm_pageout_fallback_object_lock(m, next)) {
vm_page_unlock(m);
VM_OBJECT_UNLOCK(object);
return (EAGAIN);
}
if (vm_page_sleep_if_busy(m, TRUE, "vpctw0")) {
VM_OBJECT_UNLOCK(object);
vm_page_lock_queues();
return (EBUSY);
}
vm_page_test_dirty(m);
if (m->dirty == 0 && m->hold_count == 0)
pmap_remove_all(m);
if (m->dirty != 0) {
vm_page_unlock(m);
if ((object->flags & OBJ_DEAD) != 0) {
VM_OBJECT_UNLOCK(object);
return (EAGAIN);
}
if (object->type == OBJT_VNODE) {
vm_page_unlock_queues();
vp = object->handle;
vm_object_reference_locked(object);
VM_OBJECT_UNLOCK(object);
(void) vn_start_write(vp, &mp, V_WAIT);
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
VM_OBJECT_LOCK(object);
vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
VM_OBJECT_UNLOCK(object);
VOP_UNLOCK(vp, 0);
VFS_UNLOCK_GIANT(vfslocked);
vm_object_deallocate(object);
vn_finished_write(mp);
vm_page_lock_queues();
return (0);
} else if (object->type == OBJT_SWAP ||
object->type == OBJT_DEFAULT) {
vm_page_unlock_queues();
m_tmp = m;
vm_pageout_flush(&m_tmp, 1, VM_PAGER_PUT_SYNC);
VM_OBJECT_UNLOCK(object);
vm_page_lock_queues();
return (0);
}
} else {
if (m->hold_count == 0)
vm_page_cache(m);
vm_page_unlock(m);
}
VM_OBJECT_UNLOCK(object);
return (0);
}
static int
vm_contig_launder(int queue, vm_paddr_t low, vm_paddr_t high)
{
vm_page_t m, next;
vm_paddr_t pa;
int error;
TAILQ_FOREACH_SAFE(m, &vm_page_queues[queue].pl, pageq, next) {
/* Skip marker pages */
if ((m->flags & PG_MARKER) != 0)
continue;
pa = VM_PAGE_TO_PHYS(m);
if (pa < low || pa + PAGE_SIZE > high)
continue;
if (!vm_pageout_page_lock(m, &next)) {
vm_page_unlock(m);
continue;
}
KASSERT(VM_PAGE_INQUEUE2(m, queue),
("vm_contig_launder: page %p's queue is not %d", m, queue));
error = vm_contig_launder_page(m, &next);
vm_page_lock_assert(m, MA_NOTOWNED);
if (error == 0)
return (TRUE);
if (error == EBUSY)
return (FALSE);
}
return (FALSE);
}
/*
* Frees the given physically contiguous pages.
*
* N.B.: Any pages with PG_ZERO set must, in fact, be zero filled.
*/
static void
vm_page_release_contig(vm_page_t m, vm_pindex_t count)
{
while (count--) {
/* Leave PG_ZERO unchanged. */
vm_page_free_toq(m);
m++;
}
}
/*
* Increase the number of cached pages.
*/
void
vm_contig_grow_cache(int tries, vm_paddr_t low, vm_paddr_t high)
{
int actl, actmax, inactl, inactmax;
vm_page_lock_queues();
inactl = 0;
inactmax = tries < 1 ? 0 : cnt.v_inactive_count;
actl = 0;
actmax = tries < 2 ? 0 : cnt.v_active_count;
again:
if (inactl < inactmax && vm_contig_launder(PQ_INACTIVE, low, high)) {
inactl++;
goto again;
}
if (actl < actmax && vm_contig_launder(PQ_ACTIVE, low, high)) {
actl++;
goto again;
}
vm_page_unlock_queues();
}
/*
* Allocates a region from the kernel address map and pages within the
* specified physical address range to the kernel object, creates a wired
* mapping from the region to these pages, and returns the region's starting
* virtual address. The allocated pages are not necessarily physically
* contiguous. If M_ZERO is specified through the given flags, then the pages
* are zeroed before they are mapped.
*/
vm_offset_t
kmem_alloc_attr(vm_map_t map, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, vm_memattr_t memattr)
{
vm_object_t object = kernel_object;
vm_offset_t addr, i, offset;
vm_page_t m;
int tries;
size = round_page(size);
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
vm_map_unlock(map);
return (0);
}
offset = addr - VM_MIN_KERNEL_ADDRESS;
vm_object_reference(object);
vm_map_insert(map, object, offset, addr, addr + size, VM_PROT_ALL,
VM_PROT_ALL, 0);
VM_OBJECT_LOCK(object);
for (i = 0; i < size; i += PAGE_SIZE) {
tries = 0;
retry:
m = vm_phys_alloc_contig(1, low, high, PAGE_SIZE, 0);
if (m == NULL) {
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
VM_OBJECT_UNLOCK(object);
vm_map_unlock(map);
vm_contig_grow_cache(tries, low, high);
vm_map_lock(map);
VM_OBJECT_LOCK(object);
goto retry;
}
while (i != 0) {
i -= PAGE_SIZE;
m = vm_page_lookup(object, OFF_TO_IDX(offset +
i));
vm_page_free(m);
}
VM_OBJECT_UNLOCK(object);
vm_map_delete(map, addr, addr + size);
vm_map_unlock(map);
return (0);
}
if (memattr != VM_MEMATTR_DEFAULT)
pmap_page_set_memattr(m, memattr);
vm_page_insert(m, object, OFF_TO_IDX(offset + i));
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
m->valid = VM_PAGE_BITS_ALL;
}
VM_OBJECT_UNLOCK(object);
vm_map_unlock(map);
vm_map_wire(map, addr, addr + size, VM_MAP_WIRE_SYSTEM |
VM_MAP_WIRE_NOHOLES);
return (addr);
}
/*
* Allocates a region from the kernel address map, inserts the
* given physically contiguous pages into the kernel object,
* creates a wired mapping from the region to the pages, and
* returns the region's starting virtual address. If M_ZERO is
* specified through the given flags, then the pages are zeroed
* before they are mapped.
*/
static vm_offset_t
contigmapping(vm_map_t map, vm_size_t size, vm_page_t m, vm_memattr_t memattr,
int flags)
{
vm_object_t object = kernel_object;
vm_offset_t addr, tmp_addr;
vm_map_lock(map);
if (vm_map_findspace(map, vm_map_min(map), size, &addr)) {
vm_map_unlock(map);
return (0);
}
vm_object_reference(object);
vm_map_insert(map, object, addr - VM_MIN_KERNEL_ADDRESS,
addr, addr + size, VM_PROT_ALL, VM_PROT_ALL, 0);
vm_map_unlock(map);
VM_OBJECT_LOCK(object);
for (tmp_addr = addr; tmp_addr < addr + size; tmp_addr += PAGE_SIZE) {
if (memattr != VM_MEMATTR_DEFAULT)
pmap_page_set_memattr(m, memattr);
vm_page_insert(m, object,
OFF_TO_IDX(tmp_addr - VM_MIN_KERNEL_ADDRESS));
if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
pmap_zero_page(m);
m->valid = VM_PAGE_BITS_ALL;
m++;
}
VM_OBJECT_UNLOCK(object);
vm_map_wire(map, addr, addr + size,
VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
return (addr);
}
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;
ret = (void *)kmem_alloc_contig(kernel_map, size, flags, low, high,
alignment, boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
vm_offset_t
kmem_alloc_contig(vm_map_t map, vm_size_t size, int flags, vm_paddr_t low,
vm_paddr_t high, unsigned long alignment, unsigned long boundary,
vm_memattr_t memattr)
{
vm_offset_t ret;
vm_page_t pages;
unsigned long npgs;
int tries;
size = round_page(size);
npgs = size >> PAGE_SHIFT;
tries = 0;
retry:
pages = vm_phys_alloc_contig(npgs, low, high, alignment, boundary);
if (pages == NULL) {
if (tries < ((flags & M_NOWAIT) != 0 ? 1 : 3)) {
vm_contig_grow_cache(tries, low, high);
tries++;
goto retry;
}
ret = 0;
} else {
ret = contigmapping(map, size, pages, memattr, flags);
if (ret == 0)
vm_page_release_contig(pages, npgs);
}
return (ret);
}
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
kmem_free(kernel_map, (vm_offset_t)addr, size);
malloc_type_freed(type, round_page(size));
}