2 * Copyright (c) 1991 Regents of the University of California.
4 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
6 * This code is derived from software contributed to Berkeley by
7 * The Mach Operating System project at Carnegie-Mellon University.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
64 * GENERAL RULES ON VM_PAGE MANIPULATION
66 * - A page queue lock is required when adding or removing a page from a
67 * page queue regardless of other locks or the busy state of a page.
69 * * In general, no thread besides the page daemon can acquire or
70 * hold more than one page queue lock at a time.
72 * * The page daemon can acquire and hold any pair of page queue
75 * - The object lock is required when inserting or removing
76 * pages from an object (vm_page_insert() or vm_page_remove()).
81 * Resident memory management module.
84 #include <sys/cdefs.h>
85 __FBSDID("$FreeBSD$");
89 #include <sys/param.h>
90 #include <sys/systm.h>
92 #include <sys/kernel.h>
93 #include <sys/limits.h>
94 #include <sys/malloc.h>
96 #include <sys/msgbuf.h>
97 #include <sys/mutex.h>
99 #include <sys/rwlock.h>
100 #include <sys/sysctl.h>
101 #include <sys/vmmeter.h>
102 #include <sys/vnode.h>
106 #include <vm/vm_param.h>
107 #include <vm/vm_kern.h>
108 #include <vm/vm_object.h>
109 #include <vm/vm_page.h>
110 #include <vm/vm_pageout.h>
111 #include <vm/vm_pager.h>
112 #include <vm/vm_phys.h>
113 #include <vm/vm_radix.h>
114 #include <vm/vm_reserv.h>
115 #include <vm/vm_extern.h>
117 #include <vm/uma_int.h>
119 #include <machine/md_var.h>
122 * Associated with page of user-allocatable memory is a
126 struct vm_domain vm_dom[MAXMEMDOM];
127 struct mtx_padalign vm_page_queue_free_mtx;
129 struct mtx_padalign pa_lock[PA_LOCK_COUNT];
131 vm_page_t vm_page_array;
132 long vm_page_array_size;
134 int vm_page_zero_count;
136 static int boot_pages = UMA_BOOT_PAGES;
137 TUNABLE_INT("vm.boot_pages", &boot_pages);
138 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0,
139 "number of pages allocated for bootstrapping the VM system");
141 static int pa_tryrelock_restart;
142 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
143 &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
145 static uma_zone_t fakepg_zone;
147 static struct vnode *vm_page_alloc_init(vm_page_t m);
148 static void vm_page_cache_turn_free(vm_page_t m);
149 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
150 static void vm_page_enqueue(int queue, vm_page_t m);
151 static void vm_page_init_fakepg(void *dummy);
152 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
153 vm_pindex_t pindex, vm_page_t mpred);
154 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
157 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL);
160 vm_page_init_fakepg(void *dummy)
163 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
164 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
167 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
168 #if PAGE_SIZE == 32768
170 CTASSERT(sizeof(u_long) >= 8);
175 * Try to acquire a physical address lock while a pmap is locked. If we
176 * fail to trylock we unlock and lock the pmap directly and cache the
177 * locked pa in *locked. The caller should then restart their loop in case
178 * the virtual to physical mapping has changed.
181 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
188 PA_LOCK_ASSERT(lockpa, MA_OWNED);
189 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
196 atomic_add_int(&pa_tryrelock_restart, 1);
205 * Sets the page size, perhaps based upon the memory
206 * size. Must be called before any use of page-size
207 * dependent functions.
210 vm_set_page_size(void)
212 if (cnt.v_page_size == 0)
213 cnt.v_page_size = PAGE_SIZE;
214 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0)
215 panic("vm_set_page_size: page size not a power of two");
219 * vm_page_blacklist_lookup:
221 * See if a physical address in this page has been listed
222 * in the blacklist tunable. Entries in the tunable are
223 * separated by spaces or commas. If an invalid integer is
224 * encountered then the rest of the string is skipped.
227 vm_page_blacklist_lookup(char *list, vm_paddr_t pa)
232 for (pos = list; *pos != '\0'; pos = cp) {
233 bad = strtoq(pos, &cp, 0);
235 if (*cp == ' ' || *cp == ',') {
242 if (pa == trunc_page(bad))
249 vm_page_domain_init(struct vm_domain *vmd)
251 struct vm_pagequeue *pq;
254 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
255 "vm inactive pagequeue";
256 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) =
257 &cnt.v_inactive_count;
258 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
259 "vm active pagequeue";
260 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) =
262 vmd->vmd_page_count = 0;
263 vmd->vmd_free_count = 0;
265 vmd->vmd_oom = FALSE;
267 for (i = 0; i < PQ_COUNT; i++) {
268 pq = &vmd->vmd_pagequeues[i];
269 TAILQ_INIT(&pq->pq_pl);
270 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
271 MTX_DEF | MTX_DUPOK);
278 * Initializes the resident memory module.
280 * Allocates memory for the page cells, and
281 * for the object/offset-to-page hash table headers.
282 * Each page cell is initialized and placed on the free list.
285 vm_page_startup(vm_offset_t vaddr)
288 vm_paddr_t page_range;
295 /* the biggest memory array is the second group of pages */
297 vm_paddr_t biggestsize;
298 vm_paddr_t low_water, high_water;
303 vaddr = round_page(vaddr);
305 for (i = 0; phys_avail[i + 1]; i += 2) {
306 phys_avail[i] = round_page(phys_avail[i]);
307 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
310 low_water = phys_avail[0];
311 high_water = phys_avail[1];
313 for (i = 0; phys_avail[i + 1]; i += 2) {
314 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i];
316 if (size > biggestsize) {
320 if (phys_avail[i] < low_water)
321 low_water = phys_avail[i];
322 if (phys_avail[i + 1] > high_water)
323 high_water = phys_avail[i + 1];
330 end = phys_avail[biggestone+1];
333 * Initialize the page and queue locks.
335 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF);
336 for (i = 0; i < PA_LOCK_COUNT; i++)
337 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
338 for (i = 0; i < vm_ndomains; i++)
339 vm_page_domain_init(&vm_dom[i]);
342 * Allocate memory for use when boot strapping the kernel memory
345 new_end = end - (boot_pages * UMA_SLAB_SIZE);
346 new_end = trunc_page(new_end);
347 mapped = pmap_map(&vaddr, new_end, end,
348 VM_PROT_READ | VM_PROT_WRITE);
349 bzero((void *)mapped, end - new_end);
350 uma_startup((void *)mapped, boot_pages);
352 #if defined(__amd64__) || defined(__i386__) || defined(__arm__) || \
355 * Allocate a bitmap to indicate that a random physical page
356 * needs to be included in a minidump.
358 * The amd64 port needs this to indicate which direct map pages
359 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
361 * However, i386 still needs this workspace internally within the
362 * minidump code. In theory, they are not needed on i386, but are
363 * included should the sf_buf code decide to use them.
366 for (i = 0; dump_avail[i + 1] != 0; i += 2)
367 if (dump_avail[i + 1] > last_pa)
368 last_pa = dump_avail[i + 1];
369 page_range = last_pa / PAGE_SIZE;
370 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
371 new_end -= vm_page_dump_size;
372 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
373 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
374 bzero((void *)vm_page_dump, vm_page_dump_size);
378 * Request that the physical pages underlying the message buffer be
379 * included in a crash dump. Since the message buffer is accessed
380 * through the direct map, they are not automatically included.
382 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
383 last_pa = pa + round_page(msgbufsize);
384 while (pa < last_pa) {
390 * Compute the number of pages of memory that will be available for
391 * use (taking into account the overhead of a page structure per
394 first_page = low_water / PAGE_SIZE;
395 #ifdef VM_PHYSSEG_SPARSE
397 for (i = 0; phys_avail[i + 1] != 0; i += 2)
398 page_range += atop(phys_avail[i + 1] - phys_avail[i]);
399 #elif defined(VM_PHYSSEG_DENSE)
400 page_range = high_water / PAGE_SIZE - first_page;
402 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
407 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
412 * Initialize the mem entry structures now, and put them in the free
415 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
416 mapped = pmap_map(&vaddr, new_end, end,
417 VM_PROT_READ | VM_PROT_WRITE);
418 vm_page_array = (vm_page_t) mapped;
419 #if VM_NRESERVLEVEL > 0
421 * Allocate memory for the reservation management system's data
424 new_end = vm_reserv_startup(&vaddr, new_end, high_water);
426 #if defined(__amd64__) || defined(__mips__)
428 * pmap_map on amd64 and mips can come out of the direct-map, not kvm
429 * like i386, so the pages must be tracked for a crashdump to include
430 * this data. This includes the vm_page_array and the early UMA
433 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
436 phys_avail[biggestone + 1] = new_end;
439 * Clear all of the page structures
441 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
442 for (i = 0; i < page_range; i++)
443 vm_page_array[i].order = VM_NFREEORDER;
444 vm_page_array_size = page_range;
447 * Initialize the physical memory allocator.
452 * Add every available physical page that is not blacklisted to
455 cnt.v_page_count = 0;
456 cnt.v_free_count = 0;
457 list = getenv("vm.blacklist");
458 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
460 last_pa = phys_avail[i + 1];
461 while (pa < last_pa) {
463 vm_page_blacklist_lookup(list, pa))
464 printf("Skipping page with pa 0x%jx\n",
467 vm_phys_add_page(pa);
472 #if VM_NRESERVLEVEL > 0
474 * Initialize the reservation management system.
482 vm_page_reference(vm_page_t m)
485 vm_page_aflag_set(m, PGA_REFERENCED);
489 * vm_page_busy_downgrade:
491 * Downgrade an exclusive busy page into a single shared busy page.
494 vm_page_busy_downgrade(vm_page_t m)
498 vm_page_assert_xbusied(m);
502 x &= VPB_BIT_WAITERS;
503 if (atomic_cmpset_rel_int(&m->busy_lock,
504 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1) | x))
512 * Return a positive value if the page is shared busied, 0 otherwise.
515 vm_page_sbusied(vm_page_t m)
520 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
526 * Shared unbusy a page.
529 vm_page_sunbusy(vm_page_t m)
533 vm_page_assert_sbusied(m);
537 if (VPB_SHARERS(x) > 1) {
538 if (atomic_cmpset_int(&m->busy_lock, x,
543 if ((x & VPB_BIT_WAITERS) == 0) {
544 KASSERT(x == VPB_SHARERS_WORD(1),
545 ("vm_page_sunbusy: invalid lock state"));
546 if (atomic_cmpset_int(&m->busy_lock,
547 VPB_SHARERS_WORD(1), VPB_UNBUSIED))
551 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS),
552 ("vm_page_sunbusy: invalid lock state for waiters"));
555 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) {
566 * vm_page_busy_sleep:
568 * Sleep and release the page lock, using the page pointer as wchan.
569 * This is used to implement the hard-path of busying mechanism.
571 * The given page must be locked.
574 vm_page_busy_sleep(vm_page_t m, const char *wmesg)
578 vm_page_lock_assert(m, MA_OWNED);
581 if (x == VPB_UNBUSIED) {
585 if ((x & VPB_BIT_WAITERS) == 0 &&
586 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS)) {
590 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0);
596 * Try to shared busy a page.
597 * If the operation succeeds 1 is returned otherwise 0.
598 * The operation never sleeps.
601 vm_page_trysbusy(vm_page_t m)
607 if ((x & VPB_BIT_SHARED) == 0)
609 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER))
615 * vm_page_xunbusy_hard:
617 * Called after the first try the exclusive unbusy of a page failed.
618 * It is assumed that the waiters bit is on.
621 vm_page_xunbusy_hard(vm_page_t m)
624 vm_page_assert_xbusied(m);
627 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
635 * Wakeup anyone waiting for the page.
636 * The ownership bits do not change.
638 * The given page must be locked.
641 vm_page_flash(vm_page_t m)
645 vm_page_lock_assert(m, MA_OWNED);
649 if ((x & VPB_BIT_WAITERS) == 0)
651 if (atomic_cmpset_int(&m->busy_lock, x,
652 x & (~VPB_BIT_WAITERS)))
659 * Keep page from being freed by the page daemon
660 * much of the same effect as wiring, except much lower
661 * overhead and should be used only for *very* temporary
662 * holding ("wiring").
665 vm_page_hold(vm_page_t mem)
668 vm_page_lock_assert(mem, MA_OWNED);
673 vm_page_unhold(vm_page_t mem)
676 vm_page_lock_assert(mem, MA_OWNED);
677 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!"));
679 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0)
680 vm_page_free_toq(mem);
684 * vm_page_unhold_pages:
686 * Unhold each of the pages that is referenced by the given array.
689 vm_page_unhold_pages(vm_page_t *ma, int count)
691 struct mtx *mtx, *new_mtx;
694 for (; count != 0; count--) {
696 * Avoid releasing and reacquiring the same page lock.
698 new_mtx = vm_page_lockptr(*ma);
699 if (mtx != new_mtx) {
713 PHYS_TO_VM_PAGE(vm_paddr_t pa)
717 #ifdef VM_PHYSSEG_SPARSE
718 m = vm_phys_paddr_to_vm_page(pa);
720 m = vm_phys_fictitious_to_vm_page(pa);
722 #elif defined(VM_PHYSSEG_DENSE)
726 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
727 m = &vm_page_array[pi - first_page];
730 return (vm_phys_fictitious_to_vm_page(pa));
732 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
739 * Create a fictitious page with the specified physical address and
740 * memory attribute. The memory attribute is the only the machine-
741 * dependent aspect of a fictitious page that must be initialized.
744 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
748 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
749 vm_page_initfake(m, paddr, memattr);
754 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
757 if ((m->flags & PG_FICTITIOUS) != 0) {
759 * The page's memattr might have changed since the
760 * previous initialization. Update the pmap to the
765 m->phys_addr = paddr;
767 /* Fictitious pages don't use "segind". */
768 m->flags = PG_FICTITIOUS;
769 /* Fictitious pages don't use "order" or "pool". */
770 m->oflags = VPO_UNMANAGED;
771 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
775 pmap_page_set_memattr(m, memattr);
781 * Release a fictitious page.
784 vm_page_putfake(vm_page_t m)
787 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
788 KASSERT((m->flags & PG_FICTITIOUS) != 0,
789 ("vm_page_putfake: bad page %p", m));
790 uma_zfree(fakepg_zone, m);
794 * vm_page_updatefake:
796 * Update the given fictitious page to the specified physical address and
800 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
803 KASSERT((m->flags & PG_FICTITIOUS) != 0,
804 ("vm_page_updatefake: bad page %p", m));
805 m->phys_addr = paddr;
806 pmap_page_set_memattr(m, memattr);
815 vm_page_free(vm_page_t m)
818 m->flags &= ~PG_ZERO;
825 * Free a page to the zerod-pages queue
828 vm_page_free_zero(vm_page_t m)
836 * Unbusy and handle the page queueing for a page from the VOP_GETPAGES()
837 * array which is not the request page.
840 vm_page_readahead_finish(vm_page_t m)
845 * Since the page is not the requested page, whether
846 * it should be activated or deactivated is not
847 * obvious. Empirical results have shown that
848 * deactivating the page is usually the best choice,
849 * unless the page is wanted by another thread.
852 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
855 vm_page_deactivate(m);
860 * Free the completely invalid page. Such page state
861 * occurs due to the short read operation which did
862 * not covered our page at all, or in case when a read
872 * vm_page_sleep_if_busy:
874 * Sleep and release the page queues lock if the page is busied.
875 * Returns TRUE if the thread slept.
877 * The given page must be unlocked and object containing it must
881 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
885 vm_page_lock_assert(m, MA_NOTOWNED);
886 VM_OBJECT_ASSERT_WLOCKED(m->object);
888 if (vm_page_busied(m)) {
890 * The page-specific object must be cached because page
891 * identity can change during the sleep, causing the
892 * re-lock of a different object.
893 * It is assumed that a reference to the object is already
894 * held by the callers.
898 VM_OBJECT_WUNLOCK(obj);
899 vm_page_busy_sleep(m, msg);
900 VM_OBJECT_WLOCK(obj);
907 * vm_page_dirty_KBI: [ internal use only ]
909 * Set all bits in the page's dirty field.
911 * The object containing the specified page must be locked if the
912 * call is made from the machine-independent layer.
914 * See vm_page_clear_dirty_mask().
916 * This function should only be called by vm_page_dirty().
919 vm_page_dirty_KBI(vm_page_t m)
922 /* These assertions refer to this operation by its public name. */
923 KASSERT((m->flags & PG_CACHED) == 0,
924 ("vm_page_dirty: page in cache!"));
925 KASSERT(!VM_PAGE_IS_FREE(m),
926 ("vm_page_dirty: page is free!"));
927 KASSERT(m->valid == VM_PAGE_BITS_ALL,
928 ("vm_page_dirty: page is invalid!"));
929 m->dirty = VM_PAGE_BITS_ALL;
933 * vm_page_insert: [ internal use only ]
935 * Inserts the given mem entry into the object and object list.
937 * The object must be locked.
940 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
944 VM_OBJECT_ASSERT_WLOCKED(object);
945 mpred = vm_radix_lookup_le(&object->rtree, pindex);
946 return (vm_page_insert_after(m, object, pindex, mpred));
950 * vm_page_insert_after:
952 * Inserts the page "m" into the specified object at offset "pindex".
954 * The page "mpred" must immediately precede the offset "pindex" within
955 * the specified object.
957 * The object must be locked.
960 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
967 VM_OBJECT_ASSERT_WLOCKED(object);
968 KASSERT(m->object == NULL,
969 ("vm_page_insert_after: page already inserted"));
971 KASSERT(mpred->object == object,
972 ("vm_page_insert_after: object doesn't contain mpred"));
973 KASSERT(mpred->pindex < pindex,
974 ("vm_page_insert_after: mpred doesn't precede pindex"));
975 msucc = TAILQ_NEXT(mpred, listq);
977 msucc = TAILQ_FIRST(&object->memq);
979 KASSERT(msucc->pindex > pindex,
980 ("vm_page_insert_after: msucc doesn't succeed pindex"));
983 * Record the object/offset pair in this page
991 * Now link into the object's ordered list of backed pages.
993 if (vm_radix_insert(&object->rtree, m)) {
998 vm_page_insert_radixdone(m, object, mpred);
1003 * vm_page_insert_radixdone:
1005 * Complete page "m" insertion into the specified object after the
1006 * radix trie hooking.
1008 * The page "mpred" must precede the offset "m->pindex" within the
1011 * The object must be locked.
1014 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1017 VM_OBJECT_ASSERT_WLOCKED(object);
1018 KASSERT(object != NULL && m->object == object,
1019 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1020 if (mpred != NULL) {
1021 KASSERT(mpred->object == object,
1022 ("vm_page_insert_after: object doesn't contain mpred"));
1023 KASSERT(mpred->pindex < m->pindex,
1024 ("vm_page_insert_after: mpred doesn't precede pindex"));
1028 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1030 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1033 * Show that the object has one more resident page.
1035 object->resident_page_count++;
1038 * Hold the vnode until the last page is released.
1040 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1041 vhold(object->handle);
1044 * Since we are inserting a new and possibly dirty page,
1045 * update the object's OBJ_MIGHTBEDIRTY flag.
1047 if (pmap_page_is_write_mapped(m))
1048 vm_object_set_writeable_dirty(object);
1054 * Removes the given mem entry from the object/offset-page
1055 * table and the object page list, but do not invalidate/terminate
1056 * the backing store.
1058 * The object must be locked. The page must be locked if it is managed.
1061 vm_page_remove(vm_page_t m)
1066 if ((m->oflags & VPO_UNMANAGED) == 0)
1067 vm_page_lock_assert(m, MA_OWNED);
1068 if ((object = m->object) == NULL)
1070 VM_OBJECT_ASSERT_WLOCKED(object);
1071 if (vm_page_xbusied(m)) {
1073 if ((m->oflags & VPO_UNMANAGED) != 0 &&
1074 !mtx_owned(vm_page_lockptr(m))) {
1079 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
1085 * Now remove from the object's list of backed pages.
1087 vm_radix_remove(&object->rtree, m->pindex);
1088 TAILQ_REMOVE(&object->memq, m, listq);
1091 * And show that the object has one fewer resident page.
1093 object->resident_page_count--;
1096 * The vnode may now be recycled.
1098 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1099 vdrop(object->handle);
1107 * Returns the page associated with the object/offset
1108 * pair specified; if none is found, NULL is returned.
1110 * The object must be locked.
1113 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1116 VM_OBJECT_ASSERT_LOCKED(object);
1117 return (vm_radix_lookup(&object->rtree, pindex));
1121 * vm_page_find_least:
1123 * Returns the page associated with the object with least pindex
1124 * greater than or equal to the parameter pindex, or NULL.
1126 * The object must be locked.
1129 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1133 VM_OBJECT_ASSERT_LOCKED(object);
1134 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1135 m = vm_radix_lookup_ge(&object->rtree, pindex);
1140 * Returns the given page's successor (by pindex) within the object if it is
1141 * resident; if none is found, NULL is returned.
1143 * The object must be locked.
1146 vm_page_next(vm_page_t m)
1150 VM_OBJECT_ASSERT_WLOCKED(m->object);
1151 if ((next = TAILQ_NEXT(m, listq)) != NULL &&
1152 next->pindex != m->pindex + 1)
1158 * Returns the given page's predecessor (by pindex) within the object if it is
1159 * resident; if none is found, NULL is returned.
1161 * The object must be locked.
1164 vm_page_prev(vm_page_t m)
1168 VM_OBJECT_ASSERT_WLOCKED(m->object);
1169 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL &&
1170 prev->pindex != m->pindex - 1)
1176 * Uses the page mnew as a replacement for an existing page at index
1177 * pindex which must be already present in the object.
1179 * The existing page must not be on a paging queue.
1182 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1184 vm_page_t mold, mpred;
1186 VM_OBJECT_ASSERT_WLOCKED(object);
1189 * This function mostly follows vm_page_insert() and
1190 * vm_page_remove() without the radix, object count and vnode
1191 * dance. Double check such functions for more comments.
1193 mpred = vm_radix_lookup(&object->rtree, pindex);
1194 KASSERT(mpred != NULL,
1195 ("vm_page_replace: replacing page not present with pindex"));
1196 mpred = TAILQ_PREV(mpred, respgs, listq);
1198 KASSERT(mpred->pindex < pindex,
1199 ("vm_page_insert_after: mpred doesn't precede pindex"));
1201 mnew->object = object;
1202 mnew->pindex = pindex;
1203 mold = vm_radix_replace(&object->rtree, mnew, pindex);
1204 KASSERT(mold->queue == PQ_NONE,
1205 ("vm_page_replace: mold is on a paging queue"));
1207 /* Detach the old page from the resident tailq. */
1208 TAILQ_REMOVE(&object->memq, mold, listq);
1210 mold->object = NULL;
1211 vm_page_xunbusy(mold);
1213 /* Insert the new page in the resident tailq. */
1215 TAILQ_INSERT_AFTER(&object->memq, mpred, mnew, listq);
1217 TAILQ_INSERT_HEAD(&object->memq, mnew, listq);
1218 if (pmap_page_is_write_mapped(mnew))
1219 vm_object_set_writeable_dirty(object);
1226 * Move the given memory entry from its
1227 * current object to the specified target object/offset.
1229 * Note: swap associated with the page must be invalidated by the move. We
1230 * have to do this for several reasons: (1) we aren't freeing the
1231 * page, (2) we are dirtying the page, (3) the VM system is probably
1232 * moving the page from object A to B, and will then later move
1233 * the backing store from A to B and we can't have a conflict.
1235 * Note: we *always* dirty the page. It is necessary both for the
1236 * fact that we moved it, and because we may be invalidating
1237 * swap. If the page is on the cache, we have to deactivate it
1238 * or vm_page_dirty() will panic. Dirty pages are not allowed
1241 * The objects must be locked.
1244 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1249 VM_OBJECT_ASSERT_WLOCKED(new_object);
1251 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1252 KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1253 ("vm_page_rename: pindex already renamed"));
1256 * Create a custom version of vm_page_insert() which does not depend
1257 * by m_prev and can cheat on the implementation aspects of the
1261 m->pindex = new_pindex;
1262 if (vm_radix_insert(&new_object->rtree, m)) {
1268 * The operation cannot fail anymore. The removal must happen before
1269 * the listq iterator is tainted.
1275 /* Return back to the new pindex to complete vm_page_insert(). */
1276 m->pindex = new_pindex;
1277 m->object = new_object;
1279 vm_page_insert_radixdone(m, new_object, mpred);
1285 * Convert all of the given object's cached pages that have a
1286 * pindex within the given range into free pages. If the value
1287 * zero is given for "end", then the range's upper bound is
1288 * infinity. If the given object is backed by a vnode and it
1289 * transitions from having one or more cached pages to none, the
1290 * vnode's hold count is reduced.
1293 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
1298 mtx_lock(&vm_page_queue_free_mtx);
1299 if (__predict_false(vm_radix_is_empty(&object->cache))) {
1300 mtx_unlock(&vm_page_queue_free_mtx);
1303 while ((m = vm_radix_lookup_ge(&object->cache, start)) != NULL) {
1304 if (end != 0 && m->pindex >= end)
1306 vm_radix_remove(&object->cache, m->pindex);
1307 vm_page_cache_turn_free(m);
1309 empty = vm_radix_is_empty(&object->cache);
1310 mtx_unlock(&vm_page_queue_free_mtx);
1311 if (object->type == OBJT_VNODE && empty)
1312 vdrop(object->handle);
1316 * Returns the cached page that is associated with the given
1317 * object and offset. If, however, none exists, returns NULL.
1319 * The free page queue must be locked.
1321 static inline vm_page_t
1322 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex)
1325 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1326 return (vm_radix_lookup(&object->cache, pindex));
1330 * Remove the given cached page from its containing object's
1331 * collection of cached pages.
1333 * The free page queue must be locked.
1336 vm_page_cache_remove(vm_page_t m)
1339 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1340 KASSERT((m->flags & PG_CACHED) != 0,
1341 ("vm_page_cache_remove: page %p is not cached", m));
1342 vm_radix_remove(&m->object->cache, m->pindex);
1344 cnt.v_cache_count--;
1348 * Transfer all of the cached pages with offset greater than or
1349 * equal to 'offidxstart' from the original object's cache to the
1350 * new object's cache. However, any cached pages with offset
1351 * greater than or equal to the new object's size are kept in the
1352 * original object. Initially, the new object's cache must be
1353 * empty. Offset 'offidxstart' in the original object must
1354 * correspond to offset zero in the new object.
1356 * The new object must be locked.
1359 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart,
1360 vm_object_t new_object)
1365 * Insertion into an object's collection of cached pages
1366 * requires the object to be locked. In contrast, removal does
1369 VM_OBJECT_ASSERT_WLOCKED(new_object);
1370 KASSERT(vm_radix_is_empty(&new_object->cache),
1371 ("vm_page_cache_transfer: object %p has cached pages",
1373 mtx_lock(&vm_page_queue_free_mtx);
1374 while ((m = vm_radix_lookup_ge(&orig_object->cache,
1375 offidxstart)) != NULL) {
1377 * Transfer all of the pages with offset greater than or
1378 * equal to 'offidxstart' from the original object's
1379 * cache to the new object's cache.
1381 if ((m->pindex - offidxstart) >= new_object->size)
1383 vm_radix_remove(&orig_object->cache, m->pindex);
1384 /* Update the page's object and offset. */
1385 m->object = new_object;
1386 m->pindex -= offidxstart;
1387 if (vm_radix_insert(&new_object->cache, m))
1388 vm_page_cache_turn_free(m);
1390 mtx_unlock(&vm_page_queue_free_mtx);
1394 * Returns TRUE if a cached page is associated with the given object and
1395 * offset, and FALSE otherwise.
1397 * The object must be locked.
1400 vm_page_is_cached(vm_object_t object, vm_pindex_t pindex)
1405 * Insertion into an object's collection of cached pages requires the
1406 * object to be locked. Therefore, if the object is locked and the
1407 * object's collection is empty, there is no need to acquire the free
1408 * page queues lock in order to prove that the specified page doesn't
1411 VM_OBJECT_ASSERT_WLOCKED(object);
1412 if (__predict_true(vm_object_cache_is_empty(object)))
1414 mtx_lock(&vm_page_queue_free_mtx);
1415 m = vm_page_cache_lookup(object, pindex);
1416 mtx_unlock(&vm_page_queue_free_mtx);
1423 * Allocate and return a page that is associated with the specified
1424 * object and offset pair. By default, this page is exclusive busied.
1426 * The caller must always specify an allocation class.
1428 * allocation classes:
1429 * VM_ALLOC_NORMAL normal process request
1430 * VM_ALLOC_SYSTEM system *really* needs a page
1431 * VM_ALLOC_INTERRUPT interrupt time request
1433 * optional allocation flags:
1434 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1435 * intends to allocate
1436 * VM_ALLOC_IFCACHED return page only if it is cached
1437 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page
1439 * VM_ALLOC_NOBUSY do not exclusive busy the page
1440 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1441 * VM_ALLOC_NOOBJ page is not associated with an object and
1442 * should not be exclusive busy
1443 * VM_ALLOC_SBUSY shared busy the allocated page
1444 * VM_ALLOC_WIRED wire the allocated page
1445 * VM_ALLOC_ZERO prefer a zeroed page
1447 * This routine may not sleep.
1450 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1452 struct vnode *vp = NULL;
1453 vm_object_t m_object;
1455 int flags, req_class;
1457 mpred = 0; /* XXX: pacify gcc */
1458 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1459 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1460 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1461 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1462 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
1465 VM_OBJECT_ASSERT_WLOCKED(object);
1467 req_class = req & VM_ALLOC_CLASS_MASK;
1470 * The page daemon is allowed to dig deeper into the free page list.
1472 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1473 req_class = VM_ALLOC_SYSTEM;
1475 if (object != NULL) {
1476 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1477 KASSERT(mpred == NULL || mpred->pindex != pindex,
1478 ("vm_page_alloc: pindex already allocated"));
1482 * The page allocation request can came from consumers which already
1483 * hold the free page queue mutex, like vm_page_insert() in
1486 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE);
1487 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved ||
1488 (req_class == VM_ALLOC_SYSTEM &&
1489 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) ||
1490 (req_class == VM_ALLOC_INTERRUPT &&
1491 cnt.v_free_count + cnt.v_cache_count > 0)) {
1493 * Allocate from the free queue if the number of free pages
1494 * exceeds the minimum for the request class.
1496 if (object != NULL &&
1497 (m = vm_page_cache_lookup(object, pindex)) != NULL) {
1498 if ((req & VM_ALLOC_IFNOTCACHED) != 0) {
1499 mtx_unlock(&vm_page_queue_free_mtx);
1502 if (vm_phys_unfree_page(m))
1503 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0);
1504 #if VM_NRESERVLEVEL > 0
1505 else if (!vm_reserv_reactivate_page(m))
1509 panic("vm_page_alloc: cache page %p is missing"
1510 " from the free queue", m);
1511 } else if ((req & VM_ALLOC_IFCACHED) != 0) {
1512 mtx_unlock(&vm_page_queue_free_mtx);
1514 #if VM_NRESERVLEVEL > 0
1515 } else if (object == NULL || (object->flags & (OBJ_COLORED |
1516 OBJ_FICTITIOUS)) != OBJ_COLORED || (m =
1517 vm_reserv_alloc_page(object, pindex, mpred)) == NULL) {
1521 m = vm_phys_alloc_pages(object != NULL ?
1522 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1523 #if VM_NRESERVLEVEL > 0
1524 if (m == NULL && vm_reserv_reclaim_inactive()) {
1525 m = vm_phys_alloc_pages(object != NULL ?
1526 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1533 * Not allocatable, give up.
1535 mtx_unlock(&vm_page_queue_free_mtx);
1536 atomic_add_int(&vm_pageout_deficit,
1537 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
1538 pagedaemon_wakeup();
1543 * At this point we had better have found a good page.
1545 KASSERT(m != NULL, ("vm_page_alloc: missing page"));
1546 KASSERT(m->queue == PQ_NONE,
1547 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue));
1548 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m));
1549 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m));
1550 KASSERT(!vm_page_sbusied(m),
1551 ("vm_page_alloc: page %p is busy", m));
1552 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m));
1553 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
1554 ("vm_page_alloc: page %p has unexpected memattr %d", m,
1555 pmap_page_get_memattr(m)));
1556 if ((m->flags & PG_CACHED) != 0) {
1557 KASSERT((m->flags & PG_ZERO) == 0,
1558 ("vm_page_alloc: cached page %p is PG_ZERO", m));
1559 KASSERT(m->valid != 0,
1560 ("vm_page_alloc: cached page %p is invalid", m));
1561 if (m->object == object && m->pindex == pindex)
1562 cnt.v_reactivated++;
1565 m_object = m->object;
1566 vm_page_cache_remove(m);
1567 if (m_object->type == OBJT_VNODE &&
1568 vm_object_cache_is_empty(m_object))
1569 vp = m_object->handle;
1571 KASSERT(VM_PAGE_IS_FREE(m),
1572 ("vm_page_alloc: page %p is not free", m));
1573 KASSERT(m->valid == 0,
1574 ("vm_page_alloc: free page %p is valid", m));
1575 vm_phys_freecnt_adj(m, -1);
1579 * Only the PG_ZERO flag is inherited. The PG_CACHED or PG_FREE flag
1580 * must be cleared before the free page queues lock is released.
1583 if (m->flags & PG_ZERO) {
1584 vm_page_zero_count--;
1585 if (req & VM_ALLOC_ZERO)
1588 if (req & VM_ALLOC_NODUMP)
1591 mtx_unlock(&vm_page_queue_free_mtx);
1593 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1595 m->busy_lock = VPB_UNBUSIED;
1596 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1597 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1598 if ((req & VM_ALLOC_SBUSY) != 0)
1599 m->busy_lock = VPB_SHARERS_WORD(1);
1600 if (req & VM_ALLOC_WIRED) {
1602 * The page lock is not required for wiring a page until that
1603 * page is inserted into the object.
1605 atomic_add_int(&cnt.v_wire_count, 1);
1610 if (object != NULL) {
1611 if (vm_page_insert_after(m, object, pindex, mpred)) {
1612 /* See the comment below about hold count. */
1615 pagedaemon_wakeup();
1616 if (req & VM_ALLOC_WIRED) {
1617 atomic_subtract_int(&cnt.v_wire_count, 1);
1625 /* Ignore device objects; the pager sets "memattr" for them. */
1626 if (object->memattr != VM_MEMATTR_DEFAULT &&
1627 (object->flags & OBJ_FICTITIOUS) == 0)
1628 pmap_page_set_memattr(m, object->memattr);
1633 * The following call to vdrop() must come after the above call
1634 * to vm_page_insert() in case both affect the same object and
1635 * vnode. Otherwise, the affected vnode's hold count could
1636 * temporarily become zero.
1642 * Don't wakeup too often - wakeup the pageout daemon when
1643 * we would be nearly out of memory.
1645 if (vm_paging_needed())
1646 pagedaemon_wakeup();
1652 vm_page_alloc_contig_vdrop(struct spglist *lst)
1655 while (!SLIST_EMPTY(lst)) {
1656 vdrop((struct vnode *)SLIST_FIRST(lst)-> plinks.s.pv);
1657 SLIST_REMOVE_HEAD(lst, plinks.s.ss);
1662 * vm_page_alloc_contig:
1664 * Allocate a contiguous set of physical pages of the given size "npages"
1665 * from the free lists. All of the physical pages must be at or above
1666 * the given physical address "low" and below the given physical address
1667 * "high". The given value "alignment" determines the alignment of the
1668 * first physical page in the set. If the given value "boundary" is
1669 * non-zero, then the set of physical pages cannot cross any physical
1670 * address boundary that is a multiple of that value. Both "alignment"
1671 * and "boundary" must be a power of two.
1673 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1674 * then the memory attribute setting for the physical pages is configured
1675 * to the object's memory attribute setting. Otherwise, the memory
1676 * attribute setting for the physical pages is configured to "memattr",
1677 * overriding the object's memory attribute setting. However, if the
1678 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1679 * memory attribute setting for the physical pages cannot be configured
1680 * to VM_MEMATTR_DEFAULT.
1682 * The caller must always specify an allocation class.
1684 * allocation classes:
1685 * VM_ALLOC_NORMAL normal process request
1686 * VM_ALLOC_SYSTEM system *really* needs a page
1687 * VM_ALLOC_INTERRUPT interrupt time request
1689 * optional allocation flags:
1690 * VM_ALLOC_NOBUSY do not exclusive busy the page
1691 * VM_ALLOC_NOOBJ page is not associated with an object and
1692 * should not be exclusive busy
1693 * VM_ALLOC_SBUSY shared busy the allocated page
1694 * VM_ALLOC_WIRED wire the allocated page
1695 * VM_ALLOC_ZERO prefer a zeroed page
1697 * This routine may not sleep.
1700 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1701 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1702 vm_paddr_t boundary, vm_memattr_t memattr)
1705 struct spglist deferred_vdrop_list;
1706 vm_page_t m, m_tmp, m_ret;
1707 u_int flags, oflags;
1710 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1711 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1712 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1713 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1714 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
1716 if (object != NULL) {
1717 VM_OBJECT_ASSERT_WLOCKED(object);
1718 KASSERT(object->type == OBJT_PHYS,
1719 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS",
1722 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
1723 req_class = req & VM_ALLOC_CLASS_MASK;
1726 * The page daemon is allowed to dig deeper into the free page list.
1728 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1729 req_class = VM_ALLOC_SYSTEM;
1731 SLIST_INIT(&deferred_vdrop_list);
1732 mtx_lock(&vm_page_queue_free_mtx);
1733 if (cnt.v_free_count + cnt.v_cache_count >= npages +
1734 cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM &&
1735 cnt.v_free_count + cnt.v_cache_count >= npages +
1736 cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT &&
1737 cnt.v_free_count + cnt.v_cache_count >= npages)) {
1738 #if VM_NRESERVLEVEL > 0
1740 if (object == NULL || (object->flags & OBJ_COLORED) == 0 ||
1741 (m_ret = vm_reserv_alloc_contig(object, pindex, npages,
1742 low, high, alignment, boundary)) == NULL)
1744 m_ret = vm_phys_alloc_contig(npages, low, high,
1745 alignment, boundary);
1747 mtx_unlock(&vm_page_queue_free_mtx);
1748 atomic_add_int(&vm_pageout_deficit, npages);
1749 pagedaemon_wakeup();
1753 for (m = m_ret; m < &m_ret[npages]; m++) {
1754 drop = vm_page_alloc_init(m);
1757 * Enqueue the vnode for deferred vdrop().
1759 m->plinks.s.pv = drop;
1760 SLIST_INSERT_HEAD(&deferred_vdrop_list, m,
1765 #if VM_NRESERVLEVEL > 0
1766 if (vm_reserv_reclaim_contig(npages, low, high, alignment,
1771 mtx_unlock(&vm_page_queue_free_mtx);
1776 * Initialize the pages. Only the PG_ZERO flag is inherited.
1779 if ((req & VM_ALLOC_ZERO) != 0)
1781 if ((req & VM_ALLOC_NODUMP) != 0)
1783 if ((req & VM_ALLOC_WIRED) != 0)
1784 atomic_add_int(&cnt.v_wire_count, npages);
1785 oflags = VPO_UNMANAGED;
1786 if (object != NULL) {
1787 if (object->memattr != VM_MEMATTR_DEFAULT &&
1788 memattr == VM_MEMATTR_DEFAULT)
1789 memattr = object->memattr;
1791 for (m = m_ret; m < &m_ret[npages]; m++) {
1793 m->flags = (m->flags | PG_NODUMP) & flags;
1794 m->busy_lock = VPB_UNBUSIED;
1795 if (object != NULL) {
1796 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
1797 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1798 if ((req & VM_ALLOC_SBUSY) != 0)
1799 m->busy_lock = VPB_SHARERS_WORD(1);
1801 if ((req & VM_ALLOC_WIRED) != 0)
1803 /* Unmanaged pages don't use "act_count". */
1805 if (object != NULL) {
1806 if (vm_page_insert(m, object, pindex)) {
1807 vm_page_alloc_contig_vdrop(
1808 &deferred_vdrop_list);
1809 if (vm_paging_needed())
1810 pagedaemon_wakeup();
1811 if ((req & VM_ALLOC_WIRED) != 0)
1812 atomic_subtract_int(&cnt.v_wire_count,
1814 for (m_tmp = m, m = m_ret;
1815 m < &m_ret[npages]; m++) {
1816 if ((req & VM_ALLOC_WIRED) != 0)
1826 if (memattr != VM_MEMATTR_DEFAULT)
1827 pmap_page_set_memattr(m, memattr);
1830 vm_page_alloc_contig_vdrop(&deferred_vdrop_list);
1831 if (vm_paging_needed())
1832 pagedaemon_wakeup();
1837 * Initialize a page that has been freshly dequeued from a freelist.
1838 * The caller has to drop the vnode returned, if it is not NULL.
1840 * This function may only be used to initialize unmanaged pages.
1842 * To be called with vm_page_queue_free_mtx held.
1844 static struct vnode *
1845 vm_page_alloc_init(vm_page_t m)
1848 vm_object_t m_object;
1850 KASSERT(m->queue == PQ_NONE,
1851 ("vm_page_alloc_init: page %p has unexpected queue %d",
1853 KASSERT(m->wire_count == 0,
1854 ("vm_page_alloc_init: page %p is wired", m));
1855 KASSERT(m->hold_count == 0,
1856 ("vm_page_alloc_init: page %p is held", m));
1857 KASSERT(!vm_page_sbusied(m),
1858 ("vm_page_alloc_init: page %p is busy", m));
1859 KASSERT(m->dirty == 0,
1860 ("vm_page_alloc_init: page %p is dirty", m));
1861 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
1862 ("vm_page_alloc_init: page %p has unexpected memattr %d",
1863 m, pmap_page_get_memattr(m)));
1864 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1866 if ((m->flags & PG_CACHED) != 0) {
1867 KASSERT((m->flags & PG_ZERO) == 0,
1868 ("vm_page_alloc_init: cached page %p is PG_ZERO", m));
1870 m_object = m->object;
1871 vm_page_cache_remove(m);
1872 if (m_object->type == OBJT_VNODE &&
1873 vm_object_cache_is_empty(m_object))
1874 drop = m_object->handle;
1876 KASSERT(VM_PAGE_IS_FREE(m),
1877 ("vm_page_alloc_init: page %p is not free", m));
1878 KASSERT(m->valid == 0,
1879 ("vm_page_alloc_init: free page %p is valid", m));
1880 vm_phys_freecnt_adj(m, -1);
1881 if ((m->flags & PG_ZERO) != 0)
1882 vm_page_zero_count--;
1884 /* Don't clear the PG_ZERO flag; we'll need it later. */
1885 m->flags &= PG_ZERO;
1890 * vm_page_alloc_freelist:
1892 * Allocate a physical page from the specified free page list.
1894 * The caller must always specify an allocation class.
1896 * allocation classes:
1897 * VM_ALLOC_NORMAL normal process request
1898 * VM_ALLOC_SYSTEM system *really* needs a page
1899 * VM_ALLOC_INTERRUPT interrupt time request
1901 * optional allocation flags:
1902 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1903 * intends to allocate
1904 * VM_ALLOC_WIRED wire the allocated page
1905 * VM_ALLOC_ZERO prefer a zeroed page
1907 * This routine may not sleep.
1910 vm_page_alloc_freelist(int flind, int req)
1917 req_class = req & VM_ALLOC_CLASS_MASK;
1920 * The page daemon is allowed to dig deeper into the free page list.
1922 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1923 req_class = VM_ALLOC_SYSTEM;
1926 * Do not allocate reserved pages unless the req has asked for it.
1928 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE);
1929 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved ||
1930 (req_class == VM_ALLOC_SYSTEM &&
1931 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) ||
1932 (req_class == VM_ALLOC_INTERRUPT &&
1933 cnt.v_free_count + cnt.v_cache_count > 0))
1934 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0);
1936 mtx_unlock(&vm_page_queue_free_mtx);
1937 atomic_add_int(&vm_pageout_deficit,
1938 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
1939 pagedaemon_wakeup();
1943 mtx_unlock(&vm_page_queue_free_mtx);
1946 drop = vm_page_alloc_init(m);
1947 mtx_unlock(&vm_page_queue_free_mtx);
1950 * Initialize the page. Only the PG_ZERO flag is inherited.
1954 if ((req & VM_ALLOC_ZERO) != 0)
1957 if ((req & VM_ALLOC_WIRED) != 0) {
1959 * The page lock is not required for wiring a page that does
1960 * not belong to an object.
1962 atomic_add_int(&cnt.v_wire_count, 1);
1965 /* Unmanaged pages don't use "act_count". */
1966 m->oflags = VPO_UNMANAGED;
1969 if (vm_paging_needed())
1970 pagedaemon_wakeup();
1975 * vm_wait: (also see VM_WAIT macro)
1977 * Sleep until free pages are available for allocation.
1978 * - Called in various places before memory allocations.
1984 mtx_lock(&vm_page_queue_free_mtx);
1985 if (curproc == pageproc) {
1986 vm_pageout_pages_needed = 1;
1987 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx,
1988 PDROP | PSWP, "VMWait", 0);
1990 if (!vm_pages_needed) {
1991 vm_pages_needed = 1;
1992 wakeup(&vm_pages_needed);
1994 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM,
2000 * vm_waitpfault: (also see VM_WAITPFAULT macro)
2002 * Sleep until free pages are available for allocation.
2003 * - Called only in vm_fault so that processes page faulting
2004 * can be easily tracked.
2005 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
2006 * processes will be able to grab memory first. Do not change
2007 * this balance without careful testing first.
2013 mtx_lock(&vm_page_queue_free_mtx);
2014 if (!vm_pages_needed) {
2015 vm_pages_needed = 1;
2016 wakeup(&vm_pages_needed);
2018 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
2022 struct vm_pagequeue *
2023 vm_page_pagequeue(vm_page_t m)
2026 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]);
2032 * Remove the given page from its current page queue.
2034 * The page must be locked.
2037 vm_page_dequeue(vm_page_t m)
2039 struct vm_pagequeue *pq;
2041 vm_page_lock_assert(m, MA_OWNED);
2042 KASSERT(m->queue != PQ_NONE,
2043 ("vm_page_dequeue: page %p is not queued", m));
2044 pq = vm_page_pagequeue(m);
2045 vm_pagequeue_lock(pq);
2047 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2048 vm_pagequeue_cnt_dec(pq);
2049 vm_pagequeue_unlock(pq);
2053 * vm_page_dequeue_locked:
2055 * Remove the given page from its current page queue.
2057 * The page and page queue must be locked.
2060 vm_page_dequeue_locked(vm_page_t m)
2062 struct vm_pagequeue *pq;
2064 vm_page_lock_assert(m, MA_OWNED);
2065 pq = vm_page_pagequeue(m);
2066 vm_pagequeue_assert_locked(pq);
2068 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2069 vm_pagequeue_cnt_dec(pq);
2075 * Add the given page to the specified page queue.
2077 * The page must be locked.
2080 vm_page_enqueue(int queue, vm_page_t m)
2082 struct vm_pagequeue *pq;
2084 vm_page_lock_assert(m, MA_OWNED);
2085 pq = &vm_phys_domain(m)->vmd_pagequeues[queue];
2086 vm_pagequeue_lock(pq);
2088 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2089 vm_pagequeue_cnt_inc(pq);
2090 vm_pagequeue_unlock(pq);
2096 * Move the given page to the tail of its current page queue.
2098 * The page must be locked.
2101 vm_page_requeue(vm_page_t m)
2103 struct vm_pagequeue *pq;
2105 vm_page_lock_assert(m, MA_OWNED);
2106 KASSERT(m->queue != PQ_NONE,
2107 ("vm_page_requeue: page %p is not queued", m));
2108 pq = vm_page_pagequeue(m);
2109 vm_pagequeue_lock(pq);
2110 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2111 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2112 vm_pagequeue_unlock(pq);
2116 * vm_page_requeue_locked:
2118 * Move the given page to the tail of its current page queue.
2120 * The page queue must be locked.
2123 vm_page_requeue_locked(vm_page_t m)
2125 struct vm_pagequeue *pq;
2127 KASSERT(m->queue != PQ_NONE,
2128 ("vm_page_requeue_locked: page %p is not queued", m));
2129 pq = vm_page_pagequeue(m);
2130 vm_pagequeue_assert_locked(pq);
2131 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2132 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2138 * Put the specified page on the active list (if appropriate).
2139 * Ensure that act_count is at least ACT_INIT but do not otherwise
2142 * The page must be locked.
2145 vm_page_activate(vm_page_t m)
2149 vm_page_lock_assert(m, MA_OWNED);
2150 if ((queue = m->queue) != PQ_ACTIVE) {
2151 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2152 if (m->act_count < ACT_INIT)
2153 m->act_count = ACT_INIT;
2154 if (queue != PQ_NONE)
2156 vm_page_enqueue(PQ_ACTIVE, m);
2158 KASSERT(queue == PQ_NONE,
2159 ("vm_page_activate: wired page %p is queued", m));
2161 if (m->act_count < ACT_INIT)
2162 m->act_count = ACT_INIT;
2167 * vm_page_free_wakeup:
2169 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
2170 * routine is called when a page has been added to the cache or free
2173 * The page queues must be locked.
2176 vm_page_free_wakeup(void)
2179 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2181 * if pageout daemon needs pages, then tell it that there are
2184 if (vm_pageout_pages_needed &&
2185 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) {
2186 wakeup(&vm_pageout_pages_needed);
2187 vm_pageout_pages_needed = 0;
2190 * wakeup processes that are waiting on memory if we hit a
2191 * high water mark. And wakeup scheduler process if we have
2192 * lots of memory. this process will swapin processes.
2194 if (vm_pages_needed && !vm_page_count_min()) {
2195 vm_pages_needed = 0;
2196 wakeup(&cnt.v_free_count);
2201 * Turn a cached page into a free page, by changing its attributes.
2202 * Keep the statistics up-to-date.
2204 * The free page queue must be locked.
2207 vm_page_cache_turn_free(vm_page_t m)
2210 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2214 /* Clear PG_CACHED and set PG_FREE. */
2215 m->flags ^= PG_CACHED | PG_FREE;
2216 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE,
2217 ("vm_page_cache_free: page %p has inconsistent flags", m));
2218 cnt.v_cache_count--;
2219 vm_phys_freecnt_adj(m, 1);
2225 * Returns the given page to the free list,
2226 * disassociating it with any VM object.
2228 * The object must be locked. The page must be locked if it is managed.
2231 vm_page_free_toq(vm_page_t m)
2234 if ((m->oflags & VPO_UNMANAGED) == 0) {
2235 vm_page_lock_assert(m, MA_OWNED);
2236 KASSERT(!pmap_page_is_mapped(m),
2237 ("vm_page_free_toq: freeing mapped page %p", m));
2239 KASSERT(m->queue == PQ_NONE,
2240 ("vm_page_free_toq: unmanaged page %p is queued", m));
2241 PCPU_INC(cnt.v_tfree);
2243 if (VM_PAGE_IS_FREE(m))
2244 panic("vm_page_free: freeing free page %p", m);
2245 else if (vm_page_sbusied(m))
2246 panic("vm_page_free: freeing busy page %p", m);
2249 * Unqueue, then remove page. Note that we cannot destroy
2250 * the page here because we do not want to call the pager's
2251 * callback routine until after we've put the page on the
2252 * appropriate free queue.
2258 * If fictitious remove object association and
2259 * return, otherwise delay object association removal.
2261 if ((m->flags & PG_FICTITIOUS) != 0) {
2268 if (m->wire_count != 0)
2269 panic("vm_page_free: freeing wired page %p", m);
2270 if (m->hold_count != 0) {
2271 m->flags &= ~PG_ZERO;
2272 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2273 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m));
2274 m->flags |= PG_UNHOLDFREE;
2277 * Restore the default memory attribute to the page.
2279 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
2280 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
2283 * Insert the page into the physical memory allocator's
2284 * cache/free page queues.
2286 mtx_lock(&vm_page_queue_free_mtx);
2287 m->flags |= PG_FREE;
2288 vm_phys_freecnt_adj(m, 1);
2289 #if VM_NRESERVLEVEL > 0
2290 if (!vm_reserv_free_page(m))
2294 vm_phys_free_pages(m, 0);
2295 if ((m->flags & PG_ZERO) != 0)
2296 ++vm_page_zero_count;
2298 vm_page_zero_idle_wakeup();
2299 vm_page_free_wakeup();
2300 mtx_unlock(&vm_page_queue_free_mtx);
2307 * Mark this page as wired down by yet
2308 * another map, removing it from paging queues
2311 * If the page is fictitious, then its wire count must remain one.
2313 * The page must be locked.
2316 vm_page_wire(vm_page_t m)
2320 * Only bump the wire statistics if the page is not already wired,
2321 * and only unqueue the page if it is on some queue (if it is unmanaged
2322 * it is already off the queues).
2324 vm_page_lock_assert(m, MA_OWNED);
2325 if ((m->flags & PG_FICTITIOUS) != 0) {
2326 KASSERT(m->wire_count == 1,
2327 ("vm_page_wire: fictitious page %p's wire count isn't one",
2331 if (m->wire_count == 0) {
2332 KASSERT((m->oflags & VPO_UNMANAGED) == 0 ||
2333 m->queue == PQ_NONE,
2334 ("vm_page_wire: unmanaged page %p is queued", m));
2336 atomic_add_int(&cnt.v_wire_count, 1);
2339 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
2345 * Release one wiring of the specified page, potentially enabling it to be
2346 * paged again. If paging is enabled, then the value of the parameter
2347 * "activate" determines to which queue the page is added. If "activate" is
2348 * non-zero, then the page is added to the active queue. Otherwise, it is
2349 * added to the inactive queue.
2351 * However, unless the page belongs to an object, it is not enqueued because
2352 * it cannot be paged out.
2354 * If a page is fictitious, then its wire count must always be one.
2356 * A managed page must be locked.
2359 vm_page_unwire(vm_page_t m, int activate)
2362 if ((m->oflags & VPO_UNMANAGED) == 0)
2363 vm_page_lock_assert(m, MA_OWNED);
2364 if ((m->flags & PG_FICTITIOUS) != 0) {
2365 KASSERT(m->wire_count == 1,
2366 ("vm_page_unwire: fictitious page %p's wire count isn't one", m));
2369 if (m->wire_count > 0) {
2371 if (m->wire_count == 0) {
2372 atomic_subtract_int(&cnt.v_wire_count, 1);
2373 if ((m->oflags & VPO_UNMANAGED) != 0 ||
2377 m->flags &= ~PG_WINATCFLS;
2378 vm_page_enqueue(activate ? PQ_ACTIVE : PQ_INACTIVE, m);
2381 panic("vm_page_unwire: page %p's wire count is zero", m);
2385 * Move the specified page to the inactive queue.
2387 * Many pages placed on the inactive queue should actually go
2388 * into the cache, but it is difficult to figure out which. What
2389 * we do instead, if the inactive target is well met, is to put
2390 * clean pages at the head of the inactive queue instead of the tail.
2391 * This will cause them to be moved to the cache more quickly and
2392 * if not actively re-referenced, reclaimed more quickly. If we just
2393 * stick these pages at the end of the inactive queue, heavy filesystem
2394 * meta-data accesses can cause an unnecessary paging load on memory bound
2395 * processes. This optimization causes one-time-use metadata to be
2396 * reused more quickly.
2398 * Normally athead is 0 resulting in LRU operation. athead is set
2399 * to 1 if we want this page to be 'as if it were placed in the cache',
2400 * except without unmapping it from the process address space.
2402 * The page must be locked.
2405 _vm_page_deactivate(vm_page_t m, int athead)
2407 struct vm_pagequeue *pq;
2410 vm_page_lock_assert(m, MA_OWNED);
2413 * Ignore if already inactive.
2415 if ((queue = m->queue) == PQ_INACTIVE)
2417 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2418 if (queue != PQ_NONE)
2420 m->flags &= ~PG_WINATCFLS;
2421 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE];
2422 vm_pagequeue_lock(pq);
2423 m->queue = PQ_INACTIVE;
2425 TAILQ_INSERT_HEAD(&pq->pq_pl, m, plinks.q);
2427 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2428 vm_pagequeue_cnt_inc(pq);
2429 vm_pagequeue_unlock(pq);
2434 * Move the specified page to the inactive queue.
2436 * The page must be locked.
2439 vm_page_deactivate(vm_page_t m)
2442 _vm_page_deactivate(m, 0);
2446 * vm_page_try_to_cache:
2448 * Returns 0 on failure, 1 on success
2451 vm_page_try_to_cache(vm_page_t m)
2454 vm_page_lock_assert(m, MA_OWNED);
2455 VM_OBJECT_ASSERT_WLOCKED(m->object);
2456 if (m->dirty || m->hold_count || m->wire_count ||
2457 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m))
2467 * vm_page_try_to_free()
2469 * Attempt to free the page. If we cannot free it, we do nothing.
2470 * 1 is returned on success, 0 on failure.
2473 vm_page_try_to_free(vm_page_t m)
2476 vm_page_lock_assert(m, MA_OWNED);
2477 if (m->object != NULL)
2478 VM_OBJECT_ASSERT_WLOCKED(m->object);
2479 if (m->dirty || m->hold_count || m->wire_count ||
2480 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m))
2492 * Put the specified page onto the page cache queue (if appropriate).
2494 * The object and page must be locked.
2497 vm_page_cache(vm_page_t m)
2500 boolean_t cache_was_empty;
2502 vm_page_lock_assert(m, MA_OWNED);
2504 VM_OBJECT_ASSERT_WLOCKED(object);
2505 if (vm_page_busied(m) || (m->oflags & VPO_UNMANAGED) ||
2506 m->hold_count || m->wire_count)
2507 panic("vm_page_cache: attempting to cache busy page");
2508 KASSERT(!pmap_page_is_mapped(m),
2509 ("vm_page_cache: page %p is mapped", m));
2510 KASSERT(m->dirty == 0, ("vm_page_cache: page %p is dirty", m));
2511 if (m->valid == 0 || object->type == OBJT_DEFAULT ||
2512 (object->type == OBJT_SWAP &&
2513 !vm_pager_has_page(object, m->pindex, NULL, NULL))) {
2515 * Hypothesis: A cache-elgible page belonging to a
2516 * default object or swap object but without a backing
2517 * store must be zero filled.
2522 KASSERT((m->flags & PG_CACHED) == 0,
2523 ("vm_page_cache: page %p is already cached", m));
2526 * Remove the page from the paging queues.
2531 * Remove the page from the object's collection of resident
2534 vm_radix_remove(&object->rtree, m->pindex);
2535 TAILQ_REMOVE(&object->memq, m, listq);
2536 object->resident_page_count--;
2539 * Restore the default memory attribute to the page.
2541 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
2542 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
2545 * Insert the page into the object's collection of cached pages
2546 * and the physical memory allocator's cache/free page queues.
2548 m->flags &= ~PG_ZERO;
2549 mtx_lock(&vm_page_queue_free_mtx);
2550 cache_was_empty = vm_radix_is_empty(&object->cache);
2551 if (vm_radix_insert(&object->cache, m)) {
2552 mtx_unlock(&vm_page_queue_free_mtx);
2553 if (object->resident_page_count == 0)
2554 vdrop(object->handle);
2561 * The above call to vm_radix_insert() could reclaim the one pre-
2562 * existing cached page from this object, resulting in a call to
2565 if (!cache_was_empty)
2566 cache_was_empty = vm_radix_is_singleton(&object->cache);
2568 m->flags |= PG_CACHED;
2569 cnt.v_cache_count++;
2570 PCPU_INC(cnt.v_tcached);
2571 #if VM_NRESERVLEVEL > 0
2572 if (!vm_reserv_free_page(m)) {
2576 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0);
2577 vm_phys_free_pages(m, 0);
2579 vm_page_free_wakeup();
2580 mtx_unlock(&vm_page_queue_free_mtx);
2583 * Increment the vnode's hold count if this is the object's only
2584 * cached page. Decrement the vnode's hold count if this was
2585 * the object's only resident page.
2587 if (object->type == OBJT_VNODE) {
2588 if (cache_was_empty && object->resident_page_count != 0)
2589 vhold(object->handle);
2590 else if (!cache_was_empty && object->resident_page_count == 0)
2591 vdrop(object->handle);
2598 * Cache, deactivate, or do nothing as appropriate. This routine
2599 * is used by madvise().
2601 * Generally speaking we want to move the page into the cache so
2602 * it gets reused quickly. However, this can result in a silly syndrome
2603 * due to the page recycling too quickly. Small objects will not be
2604 * fully cached. On the other hand, if we move the page to the inactive
2605 * queue we wind up with a problem whereby very large objects
2606 * unnecessarily blow away our inactive and cache queues.
2608 * The solution is to move the pages based on a fixed weighting. We
2609 * either leave them alone, deactivate them, or move them to the cache,
2610 * where moving them to the cache has the highest weighting.
2611 * By forcing some pages into other queues we eventually force the
2612 * system to balance the queues, potentially recovering other unrelated
2613 * space from active. The idea is to not force this to happen too
2616 * The object and page must be locked.
2619 vm_page_advise(vm_page_t m, int advice)
2623 vm_page_assert_locked(m);
2624 VM_OBJECT_ASSERT_WLOCKED(m->object);
2625 if (advice == MADV_FREE) {
2627 * Mark the page clean. This will allow the page to be freed
2628 * up by the system. However, such pages are often reused
2629 * quickly by malloc() so we do not do anything that would
2630 * cause a page fault if we can help it.
2632 * Specifically, we do not try to actually free the page now
2633 * nor do we try to put it in the cache (which would cause a
2634 * page fault on reuse).
2636 * But we do make the page is freeable as we can without
2637 * actually taking the step of unmapping it.
2641 } else if (advice != MADV_DONTNEED)
2643 dnw = PCPU_GET(dnweight);
2647 * Occasionally leave the page alone.
2649 if ((dnw & 0x01F0) == 0 || m->queue == PQ_INACTIVE) {
2650 if (m->act_count >= ACT_INIT)
2656 * Clear any references to the page. Otherwise, the page daemon will
2657 * immediately reactivate the page.
2659 vm_page_aflag_clear(m, PGA_REFERENCED);
2661 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
2664 if (m->dirty || (dnw & 0x0070) == 0) {
2666 * Deactivate the page 3 times out of 32.
2671 * Cache the page 28 times out of every 32. Note that
2672 * the page is deactivated instead of cached, but placed
2673 * at the head of the queue instead of the tail.
2677 _vm_page_deactivate(m, head);
2681 * Grab a page, waiting until we are waken up due to the page
2682 * changing state. We keep on waiting, if the page continues
2683 * to be in the object. If the page doesn't exist, first allocate it
2684 * and then conditionally zero it.
2686 * This routine may sleep.
2688 * The object must be locked on entry. The lock will, however, be released
2689 * and reacquired if the routine sleeps.
2692 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
2697 VM_OBJECT_ASSERT_WLOCKED(object);
2698 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
2699 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
2700 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
2702 if ((m = vm_page_lookup(object, pindex)) != NULL) {
2703 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
2704 vm_page_xbusied(m) : vm_page_busied(m);
2707 * Reference the page before unlocking and
2708 * sleeping so that the page daemon is less
2709 * likely to reclaim it.
2711 vm_page_aflag_set(m, PGA_REFERENCED);
2713 VM_OBJECT_WUNLOCK(object);
2714 vm_page_busy_sleep(m, "pgrbwt");
2715 VM_OBJECT_WLOCK(object);
2718 if ((allocflags & VM_ALLOC_WIRED) != 0) {
2724 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
2726 if ((allocflags & VM_ALLOC_SBUSY) != 0)
2731 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_IGN_SBUSY);
2733 VM_OBJECT_WUNLOCK(object);
2735 VM_OBJECT_WLOCK(object);
2737 } else if (m->valid != 0)
2739 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
2745 * Mapping function for valid or dirty bits in a page.
2747 * Inputs are required to range within a page.
2750 vm_page_bits(int base, int size)
2756 base + size <= PAGE_SIZE,
2757 ("vm_page_bits: illegal base/size %d/%d", base, size)
2760 if (size == 0) /* handle degenerate case */
2763 first_bit = base >> DEV_BSHIFT;
2764 last_bit = (base + size - 1) >> DEV_BSHIFT;
2766 return (((vm_page_bits_t)2 << last_bit) -
2767 ((vm_page_bits_t)1 << first_bit));
2771 * vm_page_set_valid_range:
2773 * Sets portions of a page valid. The arguments are expected
2774 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
2775 * of any partial chunks touched by the range. The invalid portion of
2776 * such chunks will be zeroed.
2778 * (base + size) must be less then or equal to PAGE_SIZE.
2781 vm_page_set_valid_range(vm_page_t m, int base, int size)
2785 VM_OBJECT_ASSERT_WLOCKED(m->object);
2786 if (size == 0) /* handle degenerate case */
2790 * If the base is not DEV_BSIZE aligned and the valid
2791 * bit is clear, we have to zero out a portion of the
2794 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
2795 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
2796 pmap_zero_page_area(m, frag, base - frag);
2799 * If the ending offset is not DEV_BSIZE aligned and the
2800 * valid bit is clear, we have to zero out a portion of
2803 endoff = base + size;
2804 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
2805 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
2806 pmap_zero_page_area(m, endoff,
2807 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
2810 * Assert that no previously invalid block that is now being validated
2813 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
2814 ("vm_page_set_valid_range: page %p is dirty", m));
2817 * Set valid bits inclusive of any overlap.
2819 m->valid |= vm_page_bits(base, size);
2823 * Clear the given bits from the specified page's dirty field.
2825 static __inline void
2826 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
2829 #if PAGE_SIZE < 16384
2834 * If the object is locked and the page is neither exclusive busy nor
2835 * write mapped, then the page's dirty field cannot possibly be
2836 * set by a concurrent pmap operation.
2838 VM_OBJECT_ASSERT_WLOCKED(m->object);
2839 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
2840 m->dirty &= ~pagebits;
2843 * The pmap layer can call vm_page_dirty() without
2844 * holding a distinguished lock. The combination of
2845 * the object's lock and an atomic operation suffice
2846 * to guarantee consistency of the page dirty field.
2848 * For PAGE_SIZE == 32768 case, compiler already
2849 * properly aligns the dirty field, so no forcible
2850 * alignment is needed. Only require existence of
2851 * atomic_clear_64 when page size is 32768.
2853 addr = (uintptr_t)&m->dirty;
2854 #if PAGE_SIZE == 32768
2855 atomic_clear_64((uint64_t *)addr, pagebits);
2856 #elif PAGE_SIZE == 16384
2857 atomic_clear_32((uint32_t *)addr, pagebits);
2858 #else /* PAGE_SIZE <= 8192 */
2860 * Use a trick to perform a 32-bit atomic on the
2861 * containing aligned word, to not depend on the existence
2862 * of atomic_clear_{8, 16}.
2864 shift = addr & (sizeof(uint32_t) - 1);
2865 #if BYTE_ORDER == BIG_ENDIAN
2866 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
2870 addr &= ~(sizeof(uint32_t) - 1);
2871 atomic_clear_32((uint32_t *)addr, pagebits << shift);
2872 #endif /* PAGE_SIZE */
2877 * vm_page_set_validclean:
2879 * Sets portions of a page valid and clean. The arguments are expected
2880 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
2881 * of any partial chunks touched by the range. The invalid portion of
2882 * such chunks will be zero'd.
2884 * (base + size) must be less then or equal to PAGE_SIZE.
2887 vm_page_set_validclean(vm_page_t m, int base, int size)
2889 vm_page_bits_t oldvalid, pagebits;
2892 VM_OBJECT_ASSERT_WLOCKED(m->object);
2893 if (size == 0) /* handle degenerate case */
2897 * If the base is not DEV_BSIZE aligned and the valid
2898 * bit is clear, we have to zero out a portion of the
2901 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
2902 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
2903 pmap_zero_page_area(m, frag, base - frag);
2906 * If the ending offset is not DEV_BSIZE aligned and the
2907 * valid bit is clear, we have to zero out a portion of
2910 endoff = base + size;
2911 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
2912 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
2913 pmap_zero_page_area(m, endoff,
2914 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
2917 * Set valid, clear dirty bits. If validating the entire
2918 * page we can safely clear the pmap modify bit. We also
2919 * use this opportunity to clear the VPO_NOSYNC flag. If a process
2920 * takes a write fault on a MAP_NOSYNC memory area the flag will
2923 * We set valid bits inclusive of any overlap, but we can only
2924 * clear dirty bits for DEV_BSIZE chunks that are fully within
2927 oldvalid = m->valid;
2928 pagebits = vm_page_bits(base, size);
2929 m->valid |= pagebits;
2931 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
2932 frag = DEV_BSIZE - frag;
2938 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
2940 if (base == 0 && size == PAGE_SIZE) {
2942 * The page can only be modified within the pmap if it is
2943 * mapped, and it can only be mapped if it was previously
2946 if (oldvalid == VM_PAGE_BITS_ALL)
2948 * Perform the pmap_clear_modify() first. Otherwise,
2949 * a concurrent pmap operation, such as
2950 * pmap_protect(), could clear a modification in the
2951 * pmap and set the dirty field on the page before
2952 * pmap_clear_modify() had begun and after the dirty
2953 * field was cleared here.
2955 pmap_clear_modify(m);
2957 m->oflags &= ~VPO_NOSYNC;
2958 } else if (oldvalid != VM_PAGE_BITS_ALL)
2959 m->dirty &= ~pagebits;
2961 vm_page_clear_dirty_mask(m, pagebits);
2965 vm_page_clear_dirty(vm_page_t m, int base, int size)
2968 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
2972 * vm_page_set_invalid:
2974 * Invalidates DEV_BSIZE'd chunks within a page. Both the
2975 * valid and dirty bits for the effected areas are cleared.
2978 vm_page_set_invalid(vm_page_t m, int base, int size)
2980 vm_page_bits_t bits;
2984 VM_OBJECT_ASSERT_WLOCKED(object);
2985 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
2986 size >= object->un_pager.vnp.vnp_size)
2987 bits = VM_PAGE_BITS_ALL;
2989 bits = vm_page_bits(base, size);
2990 if (m->valid == VM_PAGE_BITS_ALL && bits != 0)
2992 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
2993 !pmap_page_is_mapped(m),
2994 ("vm_page_set_invalid: page %p is mapped", m));
3000 * vm_page_zero_invalid()
3002 * The kernel assumes that the invalid portions of a page contain
3003 * garbage, but such pages can be mapped into memory by user code.
3004 * When this occurs, we must zero out the non-valid portions of the
3005 * page so user code sees what it expects.
3007 * Pages are most often semi-valid when the end of a file is mapped
3008 * into memory and the file's size is not page aligned.
3011 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3016 VM_OBJECT_ASSERT_WLOCKED(m->object);
3018 * Scan the valid bits looking for invalid sections that
3019 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
3020 * valid bit may be set ) have already been zerod by
3021 * vm_page_set_validclean().
3023 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3024 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3025 (m->valid & ((vm_page_bits_t)1 << i))) {
3027 pmap_zero_page_area(m,
3028 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
3035 * setvalid is TRUE when we can safely set the zero'd areas
3036 * as being valid. We can do this if there are no cache consistancy
3037 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3040 m->valid = VM_PAGE_BITS_ALL;
3046 * Is (partial) page valid? Note that the case where size == 0
3047 * will return FALSE in the degenerate case where the page is
3048 * entirely invalid, and TRUE otherwise.
3051 vm_page_is_valid(vm_page_t m, int base, int size)
3053 vm_page_bits_t bits;
3055 VM_OBJECT_ASSERT_LOCKED(m->object);
3056 bits = vm_page_bits(base, size);
3057 return (m->valid != 0 && (m->valid & bits) == bits);
3061 * Set the page's dirty bits if the page is modified.
3064 vm_page_test_dirty(vm_page_t m)
3067 VM_OBJECT_ASSERT_WLOCKED(m->object);
3068 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
3073 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
3076 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
3080 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
3083 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
3087 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
3090 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
3093 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
3095 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
3098 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
3102 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
3105 mtx_assert_(vm_page_lockptr(m), a, file, line);
3111 vm_page_object_lock_assert(vm_page_t m)
3115 * Certain of the page's fields may only be modified by the
3116 * holder of the containing object's lock or the exclusive busy.
3117 * holder. Unfortunately, the holder of the write busy is
3118 * not recorded, and thus cannot be checked here.
3120 if (m->object != NULL && !vm_page_xbusied(m))
3121 VM_OBJECT_ASSERT_WLOCKED(m->object);
3125 #include "opt_ddb.h"
3127 #include <sys/kernel.h>
3129 #include <ddb/ddb.h>
3131 DB_SHOW_COMMAND(page, vm_page_print_page_info)
3133 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count);
3134 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count);
3135 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count);
3136 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count);
3137 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count);
3138 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved);
3139 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min);
3140 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target);
3141 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min);
3142 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target);
3145 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
3149 db_printf("pq_free %d pq_cache %d\n",
3150 cnt.v_free_count, cnt.v_cache_count);
3151 for (dom = 0; dom < vm_ndomains; dom++) {
3153 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pass %d\n",
3155 vm_dom[dom].vmd_page_count,
3156 vm_dom[dom].vmd_free_count,
3157 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
3158 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
3159 vm_dom[dom].vmd_pass);
3163 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
3169 db_printf("show pginfo addr\n");
3173 phys = strchr(modif, 'p') != NULL;
3175 m = PHYS_TO_VM_PAGE(addr);
3177 m = (vm_page_t)addr;
3179 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n"
3180 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
3181 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
3182 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags,
3183 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);