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 * 3. 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/linker.h>
95 #include <sys/malloc.h>
97 #include <sys/msgbuf.h>
98 #include <sys/mutex.h>
100 #include <sys/rwlock.h>
101 #include <sys/sbuf.h>
103 #include <sys/sysctl.h>
104 #include <sys/vmmeter.h>
105 #include <sys/vnode.h>
109 #include <vm/vm_param.h>
110 #include <vm/vm_kern.h>
111 #include <vm/vm_object.h>
112 #include <vm/vm_page.h>
113 #include <vm/vm_pageout.h>
114 #include <vm/vm_pager.h>
115 #include <vm/vm_phys.h>
116 #include <vm/vm_radix.h>
117 #include <vm/vm_reserv.h>
118 #include <vm/vm_extern.h>
120 #include <vm/uma_int.h>
122 #include <machine/md_var.h>
125 * Associated with page of user-allocatable memory is a
129 struct vm_domain vm_dom[MAXMEMDOM];
130 struct mtx_padalign vm_page_queue_free_mtx;
132 struct mtx_padalign pa_lock[PA_LOCK_COUNT];
135 * bogus page -- for I/O to/from partially complete buffers,
136 * or for paging into sparsely invalid regions.
138 vm_page_t bogus_page;
140 vm_page_t vm_page_array;
141 long vm_page_array_size;
144 static int boot_pages = UMA_BOOT_PAGES;
145 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
147 "number of pages allocated for bootstrapping the VM system");
149 static int pa_tryrelock_restart;
150 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
151 &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
153 static TAILQ_HEAD(, vm_page) blacklist_head;
154 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
155 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
156 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
158 /* Is the page daemon waiting for free pages? */
159 static int vm_pageout_pages_needed;
161 static uma_zone_t fakepg_zone;
163 static void vm_page_alloc_check(vm_page_t m);
164 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
165 static void vm_page_enqueue(uint8_t queue, vm_page_t m);
166 static void vm_page_free_wakeup(void);
167 static void vm_page_init(void *dummy);
168 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
169 vm_pindex_t pindex, vm_page_t mpred);
170 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
172 static int vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
175 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL);
178 vm_page_init(void *dummy)
181 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
182 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
183 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ |
184 VM_ALLOC_NORMAL | VM_ALLOC_WIRED);
187 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
188 #if PAGE_SIZE == 32768
190 CTASSERT(sizeof(u_long) >= 8);
195 * Try to acquire a physical address lock while a pmap is locked. If we
196 * fail to trylock we unlock and lock the pmap directly and cache the
197 * locked pa in *locked. The caller should then restart their loop in case
198 * the virtual to physical mapping has changed.
201 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
208 PA_LOCK_ASSERT(lockpa, MA_OWNED);
209 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
216 atomic_add_int(&pa_tryrelock_restart, 1);
225 * Sets the page size, perhaps based upon the memory
226 * size. Must be called before any use of page-size
227 * dependent functions.
230 vm_set_page_size(void)
232 if (vm_cnt.v_page_size == 0)
233 vm_cnt.v_page_size = PAGE_SIZE;
234 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
235 panic("vm_set_page_size: page size not a power of two");
239 * vm_page_blacklist_next:
241 * Find the next entry in the provided string of blacklist
242 * addresses. Entries are separated by space, comma, or newline.
243 * If an invalid integer is encountered then the rest of the
244 * string is skipped. Updates the list pointer to the next
245 * character, or NULL if the string is exhausted or invalid.
248 vm_page_blacklist_next(char **list, char *end)
253 if (list == NULL || *list == NULL)
261 * If there's no end pointer then the buffer is coming from
262 * the kenv and we know it's null-terminated.
265 end = *list + strlen(*list);
267 /* Ensure that strtoq() won't walk off the end */
269 if (*end == '\n' || *end == ' ' || *end == ',')
272 printf("Blacklist not terminated, skipping\n");
278 for (pos = *list; *pos != '\0'; pos = cp) {
279 bad = strtoq(pos, &cp, 0);
280 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
289 if (*cp == '\0' || ++cp >= end)
293 return (trunc_page(bad));
295 printf("Garbage in RAM blacklist, skipping\n");
301 * vm_page_blacklist_check:
303 * Iterate through the provided string of blacklist addresses, pulling
304 * each entry out of the physical allocator free list and putting it
305 * onto a list for reporting via the vm.page_blacklist sysctl.
308 vm_page_blacklist_check(char *list, char *end)
316 while (next != NULL) {
317 if ((pa = vm_page_blacklist_next(&next, end)) == 0)
319 m = vm_phys_paddr_to_vm_page(pa);
322 mtx_lock(&vm_page_queue_free_mtx);
323 ret = vm_phys_unfree_page(m);
324 mtx_unlock(&vm_page_queue_free_mtx);
326 TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
328 printf("Skipping page with pa 0x%jx\n",
335 * vm_page_blacklist_load:
337 * Search for a special module named "ram_blacklist". It'll be a
338 * plain text file provided by the user via the loader directive
342 vm_page_blacklist_load(char **list, char **end)
351 mod = preload_search_by_type("ram_blacklist");
353 ptr = preload_fetch_addr(mod);
354 len = preload_fetch_size(mod);
365 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
372 error = sysctl_wire_old_buffer(req, 0);
375 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
376 TAILQ_FOREACH(m, &blacklist_head, listq) {
377 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
378 (uintmax_t)m->phys_addr);
381 error = sbuf_finish(&sbuf);
387 vm_page_domain_init(struct vm_domain *vmd)
389 struct vm_pagequeue *pq;
392 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
393 "vm inactive pagequeue";
394 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) =
395 &vm_cnt.v_inactive_count;
396 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
397 "vm active pagequeue";
398 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) =
399 &vm_cnt.v_active_count;
400 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) =
401 "vm laundry pagequeue";
402 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_vcnt) =
403 &vm_cnt.v_laundry_count;
404 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) =
405 "vm unswappable pagequeue";
406 /* Unswappable dirty pages are counted as being in the laundry. */
407 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_vcnt) =
408 &vm_cnt.v_laundry_count;
409 vmd->vmd_page_count = 0;
410 vmd->vmd_free_count = 0;
412 vmd->vmd_oom = FALSE;
413 for (i = 0; i < PQ_COUNT; i++) {
414 pq = &vmd->vmd_pagequeues[i];
415 TAILQ_INIT(&pq->pq_pl);
416 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
417 MTX_DEF | MTX_DUPOK);
424 * Initializes the resident memory module. Allocates physical memory for
425 * bootstrapping UMA and some data structures that are used to manage
426 * physical pages. Initializes these structures, and populates the free
430 vm_page_startup(vm_offset_t vaddr)
433 vm_paddr_t high_avail, low_avail, page_range, size;
438 char *list, *listend;
440 vm_paddr_t biggestsize;
446 vaddr = round_page(vaddr);
448 for (i = 0; phys_avail[i + 1]; i += 2) {
449 phys_avail[i] = round_page(phys_avail[i]);
450 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
452 for (i = 0; phys_avail[i + 1]; i += 2) {
453 size = phys_avail[i + 1] - phys_avail[i];
454 if (size > biggestsize) {
460 end = phys_avail[biggestone+1];
463 * Initialize the page and queue locks.
465 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF);
466 for (i = 0; i < PA_LOCK_COUNT; i++)
467 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
468 for (i = 0; i < vm_ndomains; i++)
469 vm_page_domain_init(&vm_dom[i]);
472 * Almost all of the pages needed for bootstrapping UMA are used
473 * for zone structures, so if the number of CPUs results in those
474 * structures taking more than one page each, we set aside more pages
475 * in proportion to the zone structure size.
477 pages_per_zone = howmany(sizeof(struct uma_zone) +
478 sizeof(struct uma_cache) * (mp_maxid + 1), UMA_SLAB_SIZE);
479 if (pages_per_zone > 1) {
480 /* Reserve more pages so that we don't run out. */
481 boot_pages = UMA_BOOT_PAGES_ZONES * pages_per_zone;
485 * Allocate memory for use when boot strapping the kernel memory
488 * CTFLAG_RDTUN doesn't work during the early boot process, so we must
489 * manually fetch the value.
491 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages);
492 new_end = end - (boot_pages * UMA_SLAB_SIZE);
493 new_end = trunc_page(new_end);
494 mapped = pmap_map(&vaddr, new_end, end,
495 VM_PROT_READ | VM_PROT_WRITE);
496 bzero((void *)mapped, end - new_end);
497 uma_startup((void *)mapped, boot_pages);
499 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
500 defined(__i386__) || defined(__mips__)
502 * Allocate a bitmap to indicate that a random physical page
503 * needs to be included in a minidump.
505 * The amd64 port needs this to indicate which direct map pages
506 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
508 * However, i386 still needs this workspace internally within the
509 * minidump code. In theory, they are not needed on i386, but are
510 * included should the sf_buf code decide to use them.
513 for (i = 0; dump_avail[i + 1] != 0; i += 2)
514 if (dump_avail[i + 1] > last_pa)
515 last_pa = dump_avail[i + 1];
516 page_range = last_pa / PAGE_SIZE;
517 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
518 new_end -= vm_page_dump_size;
519 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
520 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
521 bzero((void *)vm_page_dump, vm_page_dump_size);
523 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
525 * Include the UMA bootstrap pages and vm_page_dump in a crash dump.
526 * When pmap_map() uses the direct map, they are not automatically
529 for (pa = new_end; pa < end; pa += PAGE_SIZE)
532 phys_avail[biggestone + 1] = new_end;
535 * Request that the physical pages underlying the message buffer be
536 * included in a crash dump. Since the message buffer is accessed
537 * through the direct map, they are not automatically included.
539 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
540 last_pa = pa + round_page(msgbufsize);
541 while (pa < last_pa) {
547 * Compute the number of pages of memory that will be available for
548 * use, taking into account the overhead of a page structure per page.
549 * In other words, solve
550 * "available physical memory" - round_page(page_range *
551 * sizeof(struct vm_page)) = page_range * PAGE_SIZE
554 low_avail = phys_avail[0];
555 high_avail = phys_avail[1];
556 for (i = 0; i < vm_phys_nsegs; i++) {
557 if (vm_phys_segs[i].start < low_avail)
558 low_avail = vm_phys_segs[i].start;
559 if (vm_phys_segs[i].end > high_avail)
560 high_avail = vm_phys_segs[i].end;
562 /* Skip the first chunk. It is already accounted for. */
563 for (i = 2; phys_avail[i + 1] != 0; i += 2) {
564 if (phys_avail[i] < low_avail)
565 low_avail = phys_avail[i];
566 if (phys_avail[i + 1] > high_avail)
567 high_avail = phys_avail[i + 1];
569 first_page = low_avail / PAGE_SIZE;
570 #ifdef VM_PHYSSEG_SPARSE
572 for (i = 0; i < vm_phys_nsegs; i++)
573 size += vm_phys_segs[i].end - vm_phys_segs[i].start;
574 for (i = 0; phys_avail[i + 1] != 0; i += 2)
575 size += phys_avail[i + 1] - phys_avail[i];
576 #elif defined(VM_PHYSSEG_DENSE)
577 size = high_avail - low_avail;
579 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
582 #ifdef VM_PHYSSEG_DENSE
584 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
585 * the overhead of a page structure per page only if vm_page_array is
586 * allocated from the last physical memory chunk. Otherwise, we must
587 * allocate page structures representing the physical memory
588 * underlying vm_page_array, even though they will not be used.
590 if (new_end != high_avail)
591 page_range = size / PAGE_SIZE;
595 page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
598 * If the partial bytes remaining are large enough for
599 * a page (PAGE_SIZE) without a corresponding
600 * 'struct vm_page', then new_end will contain an
601 * extra page after subtracting the length of the VM
602 * page array. Compensate by subtracting an extra
605 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
606 if (new_end == high_avail)
607 high_avail -= PAGE_SIZE;
608 new_end -= PAGE_SIZE;
614 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
615 * However, because this page is allocated from KVM, out-of-bounds
616 * accesses using the direct map will not be trapped.
621 * Allocate physical memory for the page structures, and map it.
623 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
624 mapped = pmap_map(&vaddr, new_end, end,
625 VM_PROT_READ | VM_PROT_WRITE);
626 vm_page_array = (vm_page_t) mapped;
627 #if VM_NRESERVLEVEL > 0
629 * Allocate physical memory for the reservation management system's
630 * data structures, and map it.
632 if (high_avail == end)
633 high_avail = new_end;
634 new_end = vm_reserv_startup(&vaddr, new_end, high_avail);
636 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
638 * Include vm_page_array and vm_reserv_array in a crash dump.
640 for (pa = new_end; pa < end; pa += PAGE_SIZE)
643 phys_avail[biggestone + 1] = new_end;
646 * Add physical memory segments corresponding to the available
649 for (i = 0; phys_avail[i + 1] != 0; i += 2)
650 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
653 * Clear all of the page structures
655 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
656 for (i = 0; i < page_range; i++)
657 vm_page_array[i].order = VM_NFREEORDER;
658 vm_page_array_size = page_range;
661 * Initialize the physical memory allocator.
666 * Add every available physical page that is not blacklisted to
669 vm_cnt.v_page_count = 0;
670 vm_cnt.v_free_count = 0;
671 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
673 last_pa = phys_avail[i + 1];
674 while (pa < last_pa) {
675 vm_phys_add_page(pa);
680 TAILQ_INIT(&blacklist_head);
681 vm_page_blacklist_load(&list, &listend);
682 vm_page_blacklist_check(list, listend);
684 list = kern_getenv("vm.blacklist");
685 vm_page_blacklist_check(list, NULL);
688 #if VM_NRESERVLEVEL > 0
690 * Initialize the reservation management system.
698 vm_page_reference(vm_page_t m)
701 vm_page_aflag_set(m, PGA_REFERENCED);
705 * vm_page_busy_downgrade:
707 * Downgrade an exclusive busy page into a single shared busy page.
710 vm_page_busy_downgrade(vm_page_t m)
715 vm_page_assert_xbusied(m);
716 locked = mtx_owned(vm_page_lockptr(m));
720 x &= VPB_BIT_WAITERS;
721 if (x != 0 && !locked)
723 if (atomic_cmpset_rel_int(&m->busy_lock,
724 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1)))
726 if (x != 0 && !locked)
739 * Return a positive value if the page is shared busied, 0 otherwise.
742 vm_page_sbusied(vm_page_t m)
747 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
753 * Shared unbusy a page.
756 vm_page_sunbusy(vm_page_t m)
760 vm_page_assert_sbusied(m);
764 if (VPB_SHARERS(x) > 1) {
765 if (atomic_cmpset_int(&m->busy_lock, x,
770 if ((x & VPB_BIT_WAITERS) == 0) {
771 KASSERT(x == VPB_SHARERS_WORD(1),
772 ("vm_page_sunbusy: invalid lock state"));
773 if (atomic_cmpset_int(&m->busy_lock,
774 VPB_SHARERS_WORD(1), VPB_UNBUSIED))
778 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS),
779 ("vm_page_sunbusy: invalid lock state for waiters"));
782 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) {
793 * vm_page_busy_sleep:
795 * Sleep and release the page lock, using the page pointer as wchan.
796 * This is used to implement the hard-path of busying mechanism.
798 * The given page must be locked.
800 * If nonshared is true, sleep only if the page is xbusy.
803 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared)
807 vm_page_assert_locked(m);
810 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) ||
811 ((x & VPB_BIT_WAITERS) == 0 &&
812 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) {
816 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0);
822 * Try to shared busy a page.
823 * If the operation succeeds 1 is returned otherwise 0.
824 * The operation never sleeps.
827 vm_page_trysbusy(vm_page_t m)
833 if ((x & VPB_BIT_SHARED) == 0)
835 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER))
841 vm_page_xunbusy_locked(vm_page_t m)
844 vm_page_assert_xbusied(m);
845 vm_page_assert_locked(m);
847 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
848 /* There is a waiter, do wakeup() instead of vm_page_flash(). */
853 vm_page_xunbusy_maybelocked(vm_page_t m)
857 vm_page_assert_xbusied(m);
860 * Fast path for unbusy. If it succeeds, we know that there
861 * are no waiters, so we do not need a wakeup.
863 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER,
867 lockacq = !mtx_owned(vm_page_lockptr(m));
870 vm_page_xunbusy_locked(m);
876 * vm_page_xunbusy_hard:
878 * Called after the first try the exclusive unbusy of a page failed.
879 * It is assumed that the waiters bit is on.
882 vm_page_xunbusy_hard(vm_page_t m)
885 vm_page_assert_xbusied(m);
888 vm_page_xunbusy_locked(m);
895 * Wakeup anyone waiting for the page.
896 * The ownership bits do not change.
898 * The given page must be locked.
901 vm_page_flash(vm_page_t m)
905 vm_page_lock_assert(m, MA_OWNED);
909 if ((x & VPB_BIT_WAITERS) == 0)
911 if (atomic_cmpset_int(&m->busy_lock, x,
912 x & (~VPB_BIT_WAITERS)))
919 * Keep page from being freed by the page daemon
920 * much of the same effect as wiring, except much lower
921 * overhead and should be used only for *very* temporary
922 * holding ("wiring").
925 vm_page_hold(vm_page_t mem)
928 vm_page_lock_assert(mem, MA_OWNED);
933 vm_page_unhold(vm_page_t mem)
936 vm_page_lock_assert(mem, MA_OWNED);
937 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!"));
939 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0)
940 vm_page_free_toq(mem);
944 * vm_page_unhold_pages:
946 * Unhold each of the pages that is referenced by the given array.
949 vm_page_unhold_pages(vm_page_t *ma, int count)
951 struct mtx *mtx, *new_mtx;
954 for (; count != 0; count--) {
956 * Avoid releasing and reacquiring the same page lock.
958 new_mtx = vm_page_lockptr(*ma);
959 if (mtx != new_mtx) {
973 PHYS_TO_VM_PAGE(vm_paddr_t pa)
977 #ifdef VM_PHYSSEG_SPARSE
978 m = vm_phys_paddr_to_vm_page(pa);
980 m = vm_phys_fictitious_to_vm_page(pa);
982 #elif defined(VM_PHYSSEG_DENSE)
986 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
987 m = &vm_page_array[pi - first_page];
990 return (vm_phys_fictitious_to_vm_page(pa));
992 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
999 * Create a fictitious page with the specified physical address and
1000 * memory attribute. The memory attribute is the only the machine-
1001 * dependent aspect of a fictitious page that must be initialized.
1004 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1008 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1009 vm_page_initfake(m, paddr, memattr);
1014 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1017 if ((m->flags & PG_FICTITIOUS) != 0) {
1019 * The page's memattr might have changed since the
1020 * previous initialization. Update the pmap to the
1025 m->phys_addr = paddr;
1027 /* Fictitious pages don't use "segind". */
1028 m->flags = PG_FICTITIOUS;
1029 /* Fictitious pages don't use "order" or "pool". */
1030 m->oflags = VPO_UNMANAGED;
1031 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1035 pmap_page_set_memattr(m, memattr);
1041 * Release a fictitious page.
1044 vm_page_putfake(vm_page_t m)
1047 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1048 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1049 ("vm_page_putfake: bad page %p", m));
1050 uma_zfree(fakepg_zone, m);
1054 * vm_page_updatefake:
1056 * Update the given fictitious page to the specified physical address and
1060 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1063 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1064 ("vm_page_updatefake: bad page %p", m));
1065 m->phys_addr = paddr;
1066 pmap_page_set_memattr(m, memattr);
1075 vm_page_free(vm_page_t m)
1078 m->flags &= ~PG_ZERO;
1079 vm_page_free_toq(m);
1083 * vm_page_free_zero:
1085 * Free a page to the zerod-pages queue
1088 vm_page_free_zero(vm_page_t m)
1091 m->flags |= PG_ZERO;
1092 vm_page_free_toq(m);
1096 * Unbusy and handle the page queueing for a page from a getpages request that
1097 * was optionally read ahead or behind.
1100 vm_page_readahead_finish(vm_page_t m)
1103 /* We shouldn't put invalid pages on queues. */
1104 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
1107 * Since the page is not the actually needed one, whether it should
1108 * be activated or deactivated is not obvious. Empirical results
1109 * have shown that deactivating the page is usually the best choice,
1110 * unless the page is wanted by another thread.
1113 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
1114 vm_page_activate(m);
1116 vm_page_deactivate(m);
1122 * vm_page_sleep_if_busy:
1124 * Sleep and release the page queues lock if the page is busied.
1125 * Returns TRUE if the thread slept.
1127 * The given page must be unlocked and object containing it must
1131 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
1135 vm_page_lock_assert(m, MA_NOTOWNED);
1136 VM_OBJECT_ASSERT_WLOCKED(m->object);
1138 if (vm_page_busied(m)) {
1140 * The page-specific object must be cached because page
1141 * identity can change during the sleep, causing the
1142 * re-lock of a different object.
1143 * It is assumed that a reference to the object is already
1144 * held by the callers.
1148 VM_OBJECT_WUNLOCK(obj);
1149 vm_page_busy_sleep(m, msg, false);
1150 VM_OBJECT_WLOCK(obj);
1157 * vm_page_dirty_KBI: [ internal use only ]
1159 * Set all bits in the page's dirty field.
1161 * The object containing the specified page must be locked if the
1162 * call is made from the machine-independent layer.
1164 * See vm_page_clear_dirty_mask().
1166 * This function should only be called by vm_page_dirty().
1169 vm_page_dirty_KBI(vm_page_t m)
1172 /* Refer to this operation by its public name. */
1173 KASSERT(m->valid == VM_PAGE_BITS_ALL,
1174 ("vm_page_dirty: page is invalid!"));
1175 m->dirty = VM_PAGE_BITS_ALL;
1179 * vm_page_insert: [ internal use only ]
1181 * Inserts the given mem entry into the object and object list.
1183 * The object must be locked.
1186 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1190 VM_OBJECT_ASSERT_WLOCKED(object);
1191 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1192 return (vm_page_insert_after(m, object, pindex, mpred));
1196 * vm_page_insert_after:
1198 * Inserts the page "m" into the specified object at offset "pindex".
1200 * The page "mpred" must immediately precede the offset "pindex" within
1201 * the specified object.
1203 * The object must be locked.
1206 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1211 VM_OBJECT_ASSERT_WLOCKED(object);
1212 KASSERT(m->object == NULL,
1213 ("vm_page_insert_after: page already inserted"));
1214 if (mpred != NULL) {
1215 KASSERT(mpred->object == object,
1216 ("vm_page_insert_after: object doesn't contain mpred"));
1217 KASSERT(mpred->pindex < pindex,
1218 ("vm_page_insert_after: mpred doesn't precede pindex"));
1219 msucc = TAILQ_NEXT(mpred, listq);
1221 msucc = TAILQ_FIRST(&object->memq);
1223 KASSERT(msucc->pindex > pindex,
1224 ("vm_page_insert_after: msucc doesn't succeed pindex"));
1227 * Record the object/offset pair in this page
1233 * Now link into the object's ordered list of backed pages.
1235 if (vm_radix_insert(&object->rtree, m)) {
1240 vm_page_insert_radixdone(m, object, mpred);
1245 * vm_page_insert_radixdone:
1247 * Complete page "m" insertion into the specified object after the
1248 * radix trie hooking.
1250 * The page "mpred" must precede the offset "m->pindex" within the
1253 * The object must be locked.
1256 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1259 VM_OBJECT_ASSERT_WLOCKED(object);
1260 KASSERT(object != NULL && m->object == object,
1261 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1262 if (mpred != NULL) {
1263 KASSERT(mpred->object == object,
1264 ("vm_page_insert_after: object doesn't contain mpred"));
1265 KASSERT(mpred->pindex < m->pindex,
1266 ("vm_page_insert_after: mpred doesn't precede pindex"));
1270 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1272 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1275 * Show that the object has one more resident page.
1277 object->resident_page_count++;
1280 * Hold the vnode until the last page is released.
1282 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1283 vhold(object->handle);
1286 * Since we are inserting a new and possibly dirty page,
1287 * update the object's OBJ_MIGHTBEDIRTY flag.
1289 if (pmap_page_is_write_mapped(m))
1290 vm_object_set_writeable_dirty(object);
1296 * Removes the specified page from its containing object, but does not
1297 * invalidate any backing storage.
1299 * The object must be locked. The page must be locked if it is managed.
1302 vm_page_remove(vm_page_t m)
1307 if ((m->oflags & VPO_UNMANAGED) == 0)
1308 vm_page_assert_locked(m);
1309 if ((object = m->object) == NULL)
1311 VM_OBJECT_ASSERT_WLOCKED(object);
1312 if (vm_page_xbusied(m))
1313 vm_page_xunbusy_maybelocked(m);
1314 mrem = vm_radix_remove(&object->rtree, m->pindex);
1315 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1318 * Now remove from the object's list of backed pages.
1320 TAILQ_REMOVE(&object->memq, m, listq);
1323 * And show that the object has one fewer resident page.
1325 object->resident_page_count--;
1328 * The vnode may now be recycled.
1330 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1331 vdrop(object->handle);
1339 * Returns the page associated with the object/offset
1340 * pair specified; if none is found, NULL is returned.
1342 * The object must be locked.
1345 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1348 VM_OBJECT_ASSERT_LOCKED(object);
1349 return (vm_radix_lookup(&object->rtree, pindex));
1353 * vm_page_find_least:
1355 * Returns the page associated with the object with least pindex
1356 * greater than or equal to the parameter pindex, or NULL.
1358 * The object must be locked.
1361 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1365 VM_OBJECT_ASSERT_LOCKED(object);
1366 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1367 m = vm_radix_lookup_ge(&object->rtree, pindex);
1372 * Returns the given page's successor (by pindex) within the object if it is
1373 * resident; if none is found, NULL is returned.
1375 * The object must be locked.
1378 vm_page_next(vm_page_t m)
1382 VM_OBJECT_ASSERT_LOCKED(m->object);
1383 if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1384 MPASS(next->object == m->object);
1385 if (next->pindex != m->pindex + 1)
1392 * Returns the given page's predecessor (by pindex) within the object if it is
1393 * resident; if none is found, NULL is returned.
1395 * The object must be locked.
1398 vm_page_prev(vm_page_t m)
1402 VM_OBJECT_ASSERT_LOCKED(m->object);
1403 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1404 MPASS(prev->object == m->object);
1405 if (prev->pindex != m->pindex - 1)
1412 * Uses the page mnew as a replacement for an existing page at index
1413 * pindex which must be already present in the object.
1415 * The existing page must not be on a paging queue.
1418 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1422 VM_OBJECT_ASSERT_WLOCKED(object);
1423 KASSERT(mnew->object == NULL,
1424 ("vm_page_replace: page already in object"));
1427 * This function mostly follows vm_page_insert() and
1428 * vm_page_remove() without the radix, object count and vnode
1429 * dance. Double check such functions for more comments.
1432 mnew->object = object;
1433 mnew->pindex = pindex;
1434 mold = vm_radix_replace(&object->rtree, mnew);
1435 KASSERT(mold->queue == PQ_NONE,
1436 ("vm_page_replace: mold is on a paging queue"));
1438 /* Keep the resident page list in sorted order. */
1439 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1440 TAILQ_REMOVE(&object->memq, mold, listq);
1442 mold->object = NULL;
1443 vm_page_xunbusy_maybelocked(mold);
1446 * The object's resident_page_count does not change because we have
1447 * swapped one page for another, but OBJ_MIGHTBEDIRTY.
1449 if (pmap_page_is_write_mapped(mnew))
1450 vm_object_set_writeable_dirty(object);
1457 * Move the given memory entry from its
1458 * current object to the specified target object/offset.
1460 * Note: swap associated with the page must be invalidated by the move. We
1461 * have to do this for several reasons: (1) we aren't freeing the
1462 * page, (2) we are dirtying the page, (3) the VM system is probably
1463 * moving the page from object A to B, and will then later move
1464 * the backing store from A to B and we can't have a conflict.
1466 * Note: we *always* dirty the page. It is necessary both for the
1467 * fact that we moved it, and because we may be invalidating
1470 * The objects must be locked.
1473 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1478 VM_OBJECT_ASSERT_WLOCKED(new_object);
1480 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1481 KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1482 ("vm_page_rename: pindex already renamed"));
1485 * Create a custom version of vm_page_insert() which does not depend
1486 * by m_prev and can cheat on the implementation aspects of the
1490 m->pindex = new_pindex;
1491 if (vm_radix_insert(&new_object->rtree, m)) {
1497 * The operation cannot fail anymore. The removal must happen before
1498 * the listq iterator is tainted.
1504 /* Return back to the new pindex to complete vm_page_insert(). */
1505 m->pindex = new_pindex;
1506 m->object = new_object;
1508 vm_page_insert_radixdone(m, new_object, mpred);
1516 * Allocate and return a page that is associated with the specified
1517 * object and offset pair. By default, this page is exclusive busied.
1519 * The caller must always specify an allocation class.
1521 * allocation classes:
1522 * VM_ALLOC_NORMAL normal process request
1523 * VM_ALLOC_SYSTEM system *really* needs a page
1524 * VM_ALLOC_INTERRUPT interrupt time request
1526 * optional allocation flags:
1527 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1528 * intends to allocate
1529 * VM_ALLOC_NOBUSY do not exclusive busy the page
1530 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1531 * VM_ALLOC_NOOBJ page is not associated with an object and
1532 * should not be exclusive busy
1533 * VM_ALLOC_SBUSY shared busy the allocated page
1534 * VM_ALLOC_WIRED wire the allocated page
1535 * VM_ALLOC_ZERO prefer a zeroed page
1537 * This routine may not sleep.
1540 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1543 int flags, req_class;
1545 mpred = NULL; /* XXX: pacify gcc */
1546 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1547 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1548 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1549 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1550 ("vm_page_alloc: inconsistent object(%p)/req(%x)", object, req));
1552 VM_OBJECT_ASSERT_WLOCKED(object);
1554 req_class = req & VM_ALLOC_CLASS_MASK;
1557 * The page daemon is allowed to dig deeper into the free page list.
1559 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1560 req_class = VM_ALLOC_SYSTEM;
1562 if (object != NULL) {
1563 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1564 KASSERT(mpred == NULL || mpred->pindex != pindex,
1565 ("vm_page_alloc: pindex already allocated"));
1569 * Allocate a page if the number of free pages exceeds the minimum
1570 * for the request class.
1572 mtx_lock(&vm_page_queue_free_mtx);
1573 if (vm_cnt.v_free_count > vm_cnt.v_free_reserved ||
1574 (req_class == VM_ALLOC_SYSTEM &&
1575 vm_cnt.v_free_count > vm_cnt.v_interrupt_free_min) ||
1576 (req_class == VM_ALLOC_INTERRUPT &&
1577 vm_cnt.v_free_count > 0)) {
1579 * Can we allocate the page from a reservation?
1581 #if VM_NRESERVLEVEL > 0
1582 if (object == NULL || (object->flags & (OBJ_COLORED |
1583 OBJ_FICTITIOUS)) != OBJ_COLORED || (m =
1584 vm_reserv_alloc_page(object, pindex, mpred)) == NULL)
1588 * If not, allocate it from the free page queues.
1590 m = vm_phys_alloc_pages(object != NULL ?
1591 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1592 #if VM_NRESERVLEVEL > 0
1593 if (m == NULL && vm_reserv_reclaim_inactive()) {
1594 m = vm_phys_alloc_pages(object != NULL ?
1595 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1602 * Not allocatable, give up.
1604 mtx_unlock(&vm_page_queue_free_mtx);
1605 atomic_add_int(&vm_pageout_deficit,
1606 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
1607 pagedaemon_wakeup();
1612 * At this point we had better have found a good page.
1614 KASSERT(m != NULL, ("vm_page_alloc: missing page"));
1615 vm_phys_freecnt_adj(m, -1);
1616 mtx_unlock(&vm_page_queue_free_mtx);
1617 vm_page_alloc_check(m);
1620 * Initialize the page. Only the PG_ZERO flag is inherited.
1623 if ((req & VM_ALLOC_ZERO) != 0)
1626 if ((req & VM_ALLOC_NODUMP) != 0)
1630 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1632 m->busy_lock = VPB_UNBUSIED;
1633 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1634 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1635 if ((req & VM_ALLOC_SBUSY) != 0)
1636 m->busy_lock = VPB_SHARERS_WORD(1);
1637 if (req & VM_ALLOC_WIRED) {
1639 * The page lock is not required for wiring a page until that
1640 * page is inserted into the object.
1642 atomic_add_int(&vm_cnt.v_wire_count, 1);
1647 if (object != NULL) {
1648 if (vm_page_insert_after(m, object, pindex, mpred)) {
1649 pagedaemon_wakeup();
1650 if (req & VM_ALLOC_WIRED) {
1651 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
1654 KASSERT(m->object == NULL, ("page %p has object", m));
1655 m->oflags = VPO_UNMANAGED;
1656 m->busy_lock = VPB_UNBUSIED;
1657 /* Don't change PG_ZERO. */
1658 vm_page_free_toq(m);
1662 /* Ignore device objects; the pager sets "memattr" for them. */
1663 if (object->memattr != VM_MEMATTR_DEFAULT &&
1664 (object->flags & OBJ_FICTITIOUS) == 0)
1665 pmap_page_set_memattr(m, object->memattr);
1670 * Don't wakeup too often - wakeup the pageout daemon when
1671 * we would be nearly out of memory.
1673 if (vm_paging_needed())
1674 pagedaemon_wakeup();
1680 * vm_page_alloc_contig:
1682 * Allocate a contiguous set of physical pages of the given size "npages"
1683 * from the free lists. All of the physical pages must be at or above
1684 * the given physical address "low" and below the given physical address
1685 * "high". The given value "alignment" determines the alignment of the
1686 * first physical page in the set. If the given value "boundary" is
1687 * non-zero, then the set of physical pages cannot cross any physical
1688 * address boundary that is a multiple of that value. Both "alignment"
1689 * and "boundary" must be a power of two.
1691 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1692 * then the memory attribute setting for the physical pages is configured
1693 * to the object's memory attribute setting. Otherwise, the memory
1694 * attribute setting for the physical pages is configured to "memattr",
1695 * overriding the object's memory attribute setting. However, if the
1696 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1697 * memory attribute setting for the physical pages cannot be configured
1698 * to VM_MEMATTR_DEFAULT.
1700 * The specified object may not contain fictitious pages.
1702 * The caller must always specify an allocation class.
1704 * allocation classes:
1705 * VM_ALLOC_NORMAL normal process request
1706 * VM_ALLOC_SYSTEM system *really* needs a page
1707 * VM_ALLOC_INTERRUPT interrupt time request
1709 * optional allocation flags:
1710 * VM_ALLOC_NOBUSY do not exclusive busy the page
1711 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1712 * VM_ALLOC_NOOBJ page is not associated with an object and
1713 * should not be exclusive busy
1714 * VM_ALLOC_SBUSY shared busy the allocated page
1715 * VM_ALLOC_WIRED wire the allocated page
1716 * VM_ALLOC_ZERO prefer a zeroed page
1718 * This routine may not sleep.
1721 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1722 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1723 vm_paddr_t boundary, vm_memattr_t memattr)
1725 vm_page_t m, m_ret, mpred;
1726 u_int busy_lock, flags, oflags;
1729 mpred = NULL; /* XXX: pacify gcc */
1730 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1731 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1732 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1733 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1734 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
1736 if (object != NULL) {
1737 VM_OBJECT_ASSERT_WLOCKED(object);
1738 KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
1739 ("vm_page_alloc_contig: object %p has fictitious pages",
1742 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
1743 req_class = req & VM_ALLOC_CLASS_MASK;
1746 * The page daemon is allowed to dig deeper into the free page list.
1748 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1749 req_class = VM_ALLOC_SYSTEM;
1751 if (object != NULL) {
1752 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1753 KASSERT(mpred == NULL || mpred->pindex != pindex,
1754 ("vm_page_alloc_contig: pindex already allocated"));
1758 * Can we allocate the pages without the number of free pages falling
1759 * below the lower bound for the allocation class?
1761 mtx_lock(&vm_page_queue_free_mtx);
1762 if (vm_cnt.v_free_count >= npages + vm_cnt.v_free_reserved ||
1763 (req_class == VM_ALLOC_SYSTEM &&
1764 vm_cnt.v_free_count >= npages + vm_cnt.v_interrupt_free_min) ||
1765 (req_class == VM_ALLOC_INTERRUPT &&
1766 vm_cnt.v_free_count >= npages)) {
1768 * Can we allocate the pages from a reservation?
1770 #if VM_NRESERVLEVEL > 0
1772 if (object == NULL || (object->flags & OBJ_COLORED) == 0 ||
1773 (m_ret = vm_reserv_alloc_contig(object, pindex, npages,
1774 low, high, alignment, boundary, mpred)) == NULL)
1777 * If not, allocate them from the free page queues.
1779 m_ret = vm_phys_alloc_contig(npages, low, high,
1780 alignment, boundary);
1782 mtx_unlock(&vm_page_queue_free_mtx);
1783 atomic_add_int(&vm_pageout_deficit, npages);
1784 pagedaemon_wakeup();
1788 vm_phys_freecnt_adj(m_ret, -npages);
1790 #if VM_NRESERVLEVEL > 0
1791 if (vm_reserv_reclaim_contig(npages, low, high, alignment,
1796 mtx_unlock(&vm_page_queue_free_mtx);
1799 for (m = m_ret; m < &m_ret[npages]; m++)
1800 vm_page_alloc_check(m);
1803 * Initialize the pages. Only the PG_ZERO flag is inherited.
1806 if ((req & VM_ALLOC_ZERO) != 0)
1808 if ((req & VM_ALLOC_NODUMP) != 0)
1810 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1812 busy_lock = VPB_UNBUSIED;
1813 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1814 busy_lock = VPB_SINGLE_EXCLUSIVER;
1815 if ((req & VM_ALLOC_SBUSY) != 0)
1816 busy_lock = VPB_SHARERS_WORD(1);
1817 if ((req & VM_ALLOC_WIRED) != 0)
1818 atomic_add_int(&vm_cnt.v_wire_count, npages);
1819 if (object != NULL) {
1820 if (object->memattr != VM_MEMATTR_DEFAULT &&
1821 memattr == VM_MEMATTR_DEFAULT)
1822 memattr = object->memattr;
1824 for (m = m_ret; m < &m_ret[npages]; m++) {
1826 m->flags = (m->flags | PG_NODUMP) & flags;
1827 m->busy_lock = busy_lock;
1828 if ((req & VM_ALLOC_WIRED) != 0)
1832 if (object != NULL) {
1833 if (vm_page_insert_after(m, object, pindex, mpred)) {
1834 pagedaemon_wakeup();
1835 if ((req & VM_ALLOC_WIRED) != 0)
1836 atomic_subtract_int(
1837 &vm_cnt.v_wire_count, npages);
1838 KASSERT(m->object == NULL,
1839 ("page %p has object", m));
1841 for (m = m_ret; m < &m_ret[npages]; m++) {
1843 (req & VM_ALLOC_WIRED) != 0)
1845 m->oflags = VPO_UNMANAGED;
1846 m->busy_lock = VPB_UNBUSIED;
1847 /* Don't change PG_ZERO. */
1848 vm_page_free_toq(m);
1855 if (memattr != VM_MEMATTR_DEFAULT)
1856 pmap_page_set_memattr(m, memattr);
1859 if (vm_paging_needed())
1860 pagedaemon_wakeup();
1865 * Check a page that has been freshly dequeued from a freelist.
1868 vm_page_alloc_check(vm_page_t m)
1871 KASSERT(m->object == NULL, ("page %p has object", m));
1872 KASSERT(m->queue == PQ_NONE,
1873 ("page %p has unexpected queue %d", m, m->queue));
1874 KASSERT(m->wire_count == 0, ("page %p is wired", m));
1875 KASSERT(m->hold_count == 0, ("page %p is held", m));
1876 KASSERT(!vm_page_busied(m), ("page %p is busy", m));
1877 KASSERT(m->dirty == 0, ("page %p is dirty", m));
1878 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
1879 ("page %p has unexpected memattr %d",
1880 m, pmap_page_get_memattr(m)));
1881 KASSERT(m->valid == 0, ("free page %p is valid", m));
1885 * vm_page_alloc_freelist:
1887 * Allocate a physical page from the specified free page list.
1889 * The caller must always specify an allocation class.
1891 * allocation classes:
1892 * VM_ALLOC_NORMAL normal process request
1893 * VM_ALLOC_SYSTEM system *really* needs a page
1894 * VM_ALLOC_INTERRUPT interrupt time request
1896 * optional allocation flags:
1897 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1898 * intends to allocate
1899 * VM_ALLOC_WIRED wire the allocated page
1900 * VM_ALLOC_ZERO prefer a zeroed page
1902 * This routine may not sleep.
1905 vm_page_alloc_freelist(int flind, int req)
1911 req_class = req & VM_ALLOC_CLASS_MASK;
1914 * The page daemon is allowed to dig deeper into the free page list.
1916 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1917 req_class = VM_ALLOC_SYSTEM;
1920 * Do not allocate reserved pages unless the req has asked for it.
1922 mtx_lock(&vm_page_queue_free_mtx);
1923 if (vm_cnt.v_free_count > vm_cnt.v_free_reserved ||
1924 (req_class == VM_ALLOC_SYSTEM &&
1925 vm_cnt.v_free_count > vm_cnt.v_interrupt_free_min) ||
1926 (req_class == VM_ALLOC_INTERRUPT &&
1927 vm_cnt.v_free_count > 0))
1928 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0);
1930 mtx_unlock(&vm_page_queue_free_mtx);
1931 atomic_add_int(&vm_pageout_deficit,
1932 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
1933 pagedaemon_wakeup();
1937 mtx_unlock(&vm_page_queue_free_mtx);
1940 vm_phys_freecnt_adj(m, -1);
1941 mtx_unlock(&vm_page_queue_free_mtx);
1942 vm_page_alloc_check(m);
1945 * Initialize the page. Only the PG_ZERO flag is inherited.
1949 if ((req & VM_ALLOC_ZERO) != 0)
1952 if ((req & VM_ALLOC_WIRED) != 0) {
1954 * The page lock is not required for wiring a page that does
1955 * not belong to an object.
1957 atomic_add_int(&vm_cnt.v_wire_count, 1);
1960 /* Unmanaged pages don't use "act_count". */
1961 m->oflags = VPO_UNMANAGED;
1962 if (vm_paging_needed())
1963 pagedaemon_wakeup();
1967 #define VPSC_ANY 0 /* No restrictions. */
1968 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
1969 #define VPSC_NOSUPER 2 /* Skip superpages. */
1972 * vm_page_scan_contig:
1974 * Scan vm_page_array[] between the specified entries "m_start" and
1975 * "m_end" for a run of contiguous physical pages that satisfy the
1976 * specified conditions, and return the lowest page in the run. The
1977 * specified "alignment" determines the alignment of the lowest physical
1978 * page in the run. If the specified "boundary" is non-zero, then the
1979 * run of physical pages cannot span a physical address that is a
1980 * multiple of "boundary".
1982 * "m_end" is never dereferenced, so it need not point to a vm_page
1983 * structure within vm_page_array[].
1985 * "npages" must be greater than zero. "m_start" and "m_end" must not
1986 * span a hole (or discontiguity) in the physical address space. Both
1987 * "alignment" and "boundary" must be a power of two.
1990 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
1991 u_long alignment, vm_paddr_t boundary, int options)
1993 struct mtx *m_mtx, *new_mtx;
1997 #if VM_NRESERVLEVEL > 0
2000 int m_inc, order, run_ext, run_len;
2002 KASSERT(npages > 0, ("npages is 0"));
2003 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2004 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2008 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2009 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2010 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2013 * If the current page would be the start of a run, check its
2014 * physical address against the end, alignment, and boundary
2015 * conditions. If it doesn't satisfy these conditions, either
2016 * terminate the scan or advance to the next page that
2017 * satisfies the failed condition.
2020 KASSERT(m_run == NULL, ("m_run != NULL"));
2021 if (m + npages > m_end)
2023 pa = VM_PAGE_TO_PHYS(m);
2024 if ((pa & (alignment - 1)) != 0) {
2025 m_inc = atop(roundup2(pa, alignment) - pa);
2028 if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
2030 m_inc = atop(roundup2(pa, boundary) - pa);
2034 KASSERT(m_run != NULL, ("m_run == NULL"));
2037 * Avoid releasing and reacquiring the same page lock.
2039 new_mtx = vm_page_lockptr(m);
2040 if (m_mtx != new_mtx) {
2048 if (m->wire_count != 0 || m->hold_count != 0)
2050 #if VM_NRESERVLEVEL > 0
2051 else if ((level = vm_reserv_level(m)) >= 0 &&
2052 (options & VPSC_NORESERV) != 0) {
2054 /* Advance to the end of the reservation. */
2055 pa = VM_PAGE_TO_PHYS(m);
2056 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2060 else if ((object = m->object) != NULL) {
2062 * The page is considered eligible for relocation if
2063 * and only if it could be laundered or reclaimed by
2066 if (!VM_OBJECT_TRYRLOCK(object)) {
2068 VM_OBJECT_RLOCK(object);
2070 if (m->object != object) {
2072 * The page may have been freed.
2074 VM_OBJECT_RUNLOCK(object);
2076 } else if (m->wire_count != 0 ||
2077 m->hold_count != 0) {
2082 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2083 ("page %p is PG_UNHOLDFREE", m));
2084 /* Don't care: PG_NODUMP, PG_ZERO. */
2085 if (object->type != OBJT_DEFAULT &&
2086 object->type != OBJT_SWAP &&
2087 object->type != OBJT_VNODE) {
2089 #if VM_NRESERVLEVEL > 0
2090 } else if ((options & VPSC_NOSUPER) != 0 &&
2091 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2093 /* Advance to the end of the superpage. */
2094 pa = VM_PAGE_TO_PHYS(m);
2095 m_inc = atop(roundup2(pa + 1,
2096 vm_reserv_size(level)) - pa);
2098 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2099 m->queue != PQ_NONE && !vm_page_busied(m)) {
2101 * The page is allocated but eligible for
2102 * relocation. Extend the current run by one
2105 KASSERT(pmap_page_get_memattr(m) ==
2107 ("page %p has an unexpected memattr", m));
2108 KASSERT((m->oflags & (VPO_SWAPINPROG |
2109 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2110 ("page %p has unexpected oflags", m));
2111 /* Don't care: VPO_NOSYNC. */
2116 VM_OBJECT_RUNLOCK(object);
2117 #if VM_NRESERVLEVEL > 0
2118 } else if (level >= 0) {
2120 * The page is reserved but not yet allocated. In
2121 * other words, it is still free. Extend the current
2126 } else if ((order = m->order) < VM_NFREEORDER) {
2128 * The page is enqueued in the physical memory
2129 * allocator's free page queues. Moreover, it is the
2130 * first page in a power-of-two-sized run of
2131 * contiguous free pages. Add these pages to the end
2132 * of the current run, and jump ahead.
2134 run_ext = 1 << order;
2138 * Skip the page for one of the following reasons: (1)
2139 * It is enqueued in the physical memory allocator's
2140 * free page queues. However, it is not the first
2141 * page in a run of contiguous free pages. (This case
2142 * rarely occurs because the scan is performed in
2143 * ascending order.) (2) It is not reserved, and it is
2144 * transitioning from free to allocated. (Conversely,
2145 * the transition from allocated to free for managed
2146 * pages is blocked by the page lock.) (3) It is
2147 * allocated but not contained by an object and not
2148 * wired, e.g., allocated by Xen's balloon driver.
2154 * Extend or reset the current run of pages.
2169 if (run_len >= npages)
2175 * vm_page_reclaim_run:
2177 * Try to relocate each of the allocated virtual pages within the
2178 * specified run of physical pages to a new physical address. Free the
2179 * physical pages underlying the relocated virtual pages. A virtual page
2180 * is relocatable if and only if it could be laundered or reclaimed by
2181 * the page daemon. Whenever possible, a virtual page is relocated to a
2182 * physical address above "high".
2184 * Returns 0 if every physical page within the run was already free or
2185 * just freed by a successful relocation. Otherwise, returns a non-zero
2186 * value indicating why the last attempt to relocate a virtual page was
2189 * "req_class" must be an allocation class.
2192 vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
2195 struct mtx *m_mtx, *new_mtx;
2196 struct spglist free;
2199 vm_page_t m, m_end, m_new;
2200 int error, order, req;
2202 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2203 ("req_class is not an allocation class"));
2207 m_end = m_run + npages;
2209 for (; error == 0 && m < m_end; m++) {
2210 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2211 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2214 * Avoid releasing and reacquiring the same page lock.
2216 new_mtx = vm_page_lockptr(m);
2217 if (m_mtx != new_mtx) {
2224 if (m->wire_count != 0 || m->hold_count != 0)
2226 else if ((object = m->object) != NULL) {
2228 * The page is relocated if and only if it could be
2229 * laundered or reclaimed by the page daemon.
2231 if (!VM_OBJECT_TRYWLOCK(object)) {
2233 VM_OBJECT_WLOCK(object);
2235 if (m->object != object) {
2237 * The page may have been freed.
2239 VM_OBJECT_WUNLOCK(object);
2241 } else if (m->wire_count != 0 ||
2242 m->hold_count != 0) {
2247 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2248 ("page %p is PG_UNHOLDFREE", m));
2249 /* Don't care: PG_NODUMP, PG_ZERO. */
2250 if (object->type != OBJT_DEFAULT &&
2251 object->type != OBJT_SWAP &&
2252 object->type != OBJT_VNODE)
2254 else if (object->memattr != VM_MEMATTR_DEFAULT)
2256 else if (m->queue != PQ_NONE && !vm_page_busied(m)) {
2257 KASSERT(pmap_page_get_memattr(m) ==
2259 ("page %p has an unexpected memattr", m));
2260 KASSERT((m->oflags & (VPO_SWAPINPROG |
2261 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2262 ("page %p has unexpected oflags", m));
2263 /* Don't care: VPO_NOSYNC. */
2264 if (m->valid != 0) {
2266 * First, try to allocate a new page
2267 * that is above "high". Failing
2268 * that, try to allocate a new page
2269 * that is below "m_run". Allocate
2270 * the new page between the end of
2271 * "m_run" and "high" only as a last
2274 req = req_class | VM_ALLOC_NOOBJ;
2275 if ((m->flags & PG_NODUMP) != 0)
2276 req |= VM_ALLOC_NODUMP;
2277 if (trunc_page(high) !=
2278 ~(vm_paddr_t)PAGE_MASK) {
2279 m_new = vm_page_alloc_contig(
2284 VM_MEMATTR_DEFAULT);
2287 if (m_new == NULL) {
2288 pa = VM_PAGE_TO_PHYS(m_run);
2289 m_new = vm_page_alloc_contig(
2291 0, pa - 1, PAGE_SIZE, 0,
2292 VM_MEMATTR_DEFAULT);
2294 if (m_new == NULL) {
2296 m_new = vm_page_alloc_contig(
2298 pa, high, PAGE_SIZE, 0,
2299 VM_MEMATTR_DEFAULT);
2301 if (m_new == NULL) {
2305 KASSERT(m_new->wire_count == 0,
2306 ("page %p is wired", m));
2309 * Replace "m" with the new page. For
2310 * vm_page_replace(), "m" must be busy
2311 * and dequeued. Finally, change "m"
2312 * as if vm_page_free() was called.
2314 if (object->ref_count != 0)
2316 m_new->aflags = m->aflags;
2317 KASSERT(m_new->oflags == VPO_UNMANAGED,
2318 ("page %p is managed", m));
2319 m_new->oflags = m->oflags & VPO_NOSYNC;
2320 pmap_copy_page(m, m_new);
2321 m_new->valid = m->valid;
2322 m_new->dirty = m->dirty;
2323 m->flags &= ~PG_ZERO;
2326 vm_page_replace_checked(m_new, object,
2332 * The new page must be deactivated
2333 * before the object is unlocked.
2335 new_mtx = vm_page_lockptr(m_new);
2336 if (m_mtx != new_mtx) {
2341 vm_page_deactivate(m_new);
2343 m->flags &= ~PG_ZERO;
2346 KASSERT(m->dirty == 0,
2347 ("page %p is dirty", m));
2349 SLIST_INSERT_HEAD(&free, m, plinks.s.ss);
2353 VM_OBJECT_WUNLOCK(object);
2355 mtx_lock(&vm_page_queue_free_mtx);
2357 if (order < VM_NFREEORDER) {
2359 * The page is enqueued in the physical memory
2360 * allocator's free page queues. Moreover, it
2361 * is the first page in a power-of-two-sized
2362 * run of contiguous free pages. Jump ahead
2363 * to the last page within that run, and
2364 * continue from there.
2366 m += (1 << order) - 1;
2368 #if VM_NRESERVLEVEL > 0
2369 else if (vm_reserv_is_page_free(m))
2372 mtx_unlock(&vm_page_queue_free_mtx);
2373 if (order == VM_NFREEORDER)
2379 if ((m = SLIST_FIRST(&free)) != NULL) {
2380 mtx_lock(&vm_page_queue_free_mtx);
2382 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
2383 vm_phys_freecnt_adj(m, 1);
2384 #if VM_NRESERVLEVEL > 0
2385 if (!vm_reserv_free_page(m))
2389 vm_phys_free_pages(m, 0);
2390 } while ((m = SLIST_FIRST(&free)) != NULL);
2391 vm_page_free_wakeup();
2392 mtx_unlock(&vm_page_queue_free_mtx);
2399 CTASSERT(powerof2(NRUNS));
2401 #define RUN_INDEX(count) ((count) & (NRUNS - 1))
2403 #define MIN_RECLAIM 8
2406 * vm_page_reclaim_contig:
2408 * Reclaim allocated, contiguous physical memory satisfying the specified
2409 * conditions by relocating the virtual pages using that physical memory.
2410 * Returns true if reclamation is successful and false otherwise. Since
2411 * relocation requires the allocation of physical pages, reclamation may
2412 * fail due to a shortage of free pages. When reclamation fails, callers
2413 * are expected to perform VM_WAIT before retrying a failed allocation
2414 * operation, e.g., vm_page_alloc_contig().
2416 * The caller must always specify an allocation class through "req".
2418 * allocation classes:
2419 * VM_ALLOC_NORMAL normal process request
2420 * VM_ALLOC_SYSTEM system *really* needs a page
2421 * VM_ALLOC_INTERRUPT interrupt time request
2423 * The optional allocation flags are ignored.
2425 * "npages" must be greater than zero. Both "alignment" and "boundary"
2426 * must be a power of two.
2429 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
2430 u_long alignment, vm_paddr_t boundary)
2432 vm_paddr_t curr_low;
2433 vm_page_t m_run, m_runs[NRUNS];
2434 u_long count, reclaimed;
2435 int error, i, options, req_class;
2437 KASSERT(npages > 0, ("npages is 0"));
2438 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2439 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2440 req_class = req & VM_ALLOC_CLASS_MASK;
2443 * The page daemon is allowed to dig deeper into the free page list.
2445 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2446 req_class = VM_ALLOC_SYSTEM;
2449 * Return if the number of free pages cannot satisfy the requested
2452 count = vm_cnt.v_free_count;
2453 if (count < npages + vm_cnt.v_free_reserved || (count < npages +
2454 vm_cnt.v_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
2455 (count < npages && req_class == VM_ALLOC_INTERRUPT))
2459 * Scan up to three times, relaxing the restrictions ("options") on
2460 * the reclamation of reservations and superpages each time.
2462 for (options = VPSC_NORESERV;;) {
2464 * Find the highest runs that satisfy the given constraints
2465 * and restrictions, and record them in "m_runs".
2470 m_run = vm_phys_scan_contig(npages, curr_low, high,
2471 alignment, boundary, options);
2474 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages);
2475 m_runs[RUN_INDEX(count)] = m_run;
2480 * Reclaim the highest runs in LIFO (descending) order until
2481 * the number of reclaimed pages, "reclaimed", is at least
2482 * MIN_RECLAIM. Reset "reclaimed" each time because each
2483 * reclamation is idempotent, and runs will (likely) recur
2484 * from one scan to the next as restrictions are relaxed.
2487 for (i = 0; count > 0 && i < NRUNS; i++) {
2489 m_run = m_runs[RUN_INDEX(count)];
2490 error = vm_page_reclaim_run(req_class, npages, m_run,
2493 reclaimed += npages;
2494 if (reclaimed >= MIN_RECLAIM)
2500 * Either relax the restrictions on the next scan or return if
2501 * the last scan had no restrictions.
2503 if (options == VPSC_NORESERV)
2504 options = VPSC_NOSUPER;
2505 else if (options == VPSC_NOSUPER)
2507 else if (options == VPSC_ANY)
2508 return (reclaimed != 0);
2513 * vm_wait: (also see VM_WAIT macro)
2515 * Sleep until free pages are available for allocation.
2516 * - Called in various places before memory allocations.
2522 mtx_lock(&vm_page_queue_free_mtx);
2523 if (curproc == pageproc) {
2524 vm_pageout_pages_needed = 1;
2525 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx,
2526 PDROP | PSWP, "VMWait", 0);
2528 if (__predict_false(pageproc == NULL))
2529 panic("vm_wait in early boot");
2530 if (!vm_pageout_wanted) {
2531 vm_pageout_wanted = true;
2532 wakeup(&vm_pageout_wanted);
2534 vm_pages_needed = true;
2535 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM,
2541 * vm_waitpfault: (also see VM_WAITPFAULT macro)
2543 * Sleep until free pages are available for allocation.
2544 * - Called only in vm_fault so that processes page faulting
2545 * can be easily tracked.
2546 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
2547 * processes will be able to grab memory first. Do not change
2548 * this balance without careful testing first.
2554 mtx_lock(&vm_page_queue_free_mtx);
2555 if (!vm_pageout_wanted) {
2556 vm_pageout_wanted = true;
2557 wakeup(&vm_pageout_wanted);
2559 vm_pages_needed = true;
2560 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
2564 struct vm_pagequeue *
2565 vm_page_pagequeue(vm_page_t m)
2568 if (vm_page_in_laundry(m))
2569 return (&vm_dom[0].vmd_pagequeues[m->queue]);
2571 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]);
2577 * Remove the given page from its current page queue.
2579 * The page must be locked.
2582 vm_page_dequeue(vm_page_t m)
2584 struct vm_pagequeue *pq;
2586 vm_page_assert_locked(m);
2587 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued",
2589 pq = vm_page_pagequeue(m);
2590 vm_pagequeue_lock(pq);
2592 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2593 vm_pagequeue_cnt_dec(pq);
2594 vm_pagequeue_unlock(pq);
2598 * vm_page_dequeue_locked:
2600 * Remove the given page from its current page queue.
2602 * The page and page queue must be locked.
2605 vm_page_dequeue_locked(vm_page_t m)
2607 struct vm_pagequeue *pq;
2609 vm_page_lock_assert(m, MA_OWNED);
2610 pq = vm_page_pagequeue(m);
2611 vm_pagequeue_assert_locked(pq);
2613 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2614 vm_pagequeue_cnt_dec(pq);
2620 * Add the given page to the specified page queue.
2622 * The page must be locked.
2625 vm_page_enqueue(uint8_t queue, vm_page_t m)
2627 struct vm_pagequeue *pq;
2629 vm_page_lock_assert(m, MA_OWNED);
2630 KASSERT(queue < PQ_COUNT,
2631 ("vm_page_enqueue: invalid queue %u request for page %p",
2633 if (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE)
2634 pq = &vm_dom[0].vmd_pagequeues[queue];
2636 pq = &vm_phys_domain(m)->vmd_pagequeues[queue];
2637 vm_pagequeue_lock(pq);
2639 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2640 vm_pagequeue_cnt_inc(pq);
2641 vm_pagequeue_unlock(pq);
2647 * Move the given page to the tail of its current page queue.
2649 * The page must be locked.
2652 vm_page_requeue(vm_page_t m)
2654 struct vm_pagequeue *pq;
2656 vm_page_lock_assert(m, MA_OWNED);
2657 KASSERT(m->queue != PQ_NONE,
2658 ("vm_page_requeue: page %p is not queued", m));
2659 pq = vm_page_pagequeue(m);
2660 vm_pagequeue_lock(pq);
2661 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2662 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2663 vm_pagequeue_unlock(pq);
2667 * vm_page_requeue_locked:
2669 * Move the given page to the tail of its current page queue.
2671 * The page queue must be locked.
2674 vm_page_requeue_locked(vm_page_t m)
2676 struct vm_pagequeue *pq;
2678 KASSERT(m->queue != PQ_NONE,
2679 ("vm_page_requeue_locked: page %p is not queued", m));
2680 pq = vm_page_pagequeue(m);
2681 vm_pagequeue_assert_locked(pq);
2682 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2683 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2689 * Put the specified page on the active list (if appropriate).
2690 * Ensure that act_count is at least ACT_INIT but do not otherwise
2693 * The page must be locked.
2696 vm_page_activate(vm_page_t m)
2700 vm_page_lock_assert(m, MA_OWNED);
2701 if ((queue = m->queue) != PQ_ACTIVE) {
2702 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2703 if (m->act_count < ACT_INIT)
2704 m->act_count = ACT_INIT;
2705 if (queue != PQ_NONE)
2707 vm_page_enqueue(PQ_ACTIVE, m);
2709 KASSERT(queue == PQ_NONE,
2710 ("vm_page_activate: wired page %p is queued", m));
2712 if (m->act_count < ACT_INIT)
2713 m->act_count = ACT_INIT;
2718 * vm_page_free_wakeup:
2720 * Helper routine for vm_page_free_toq(). This routine is called
2721 * when a page is added to the free queues.
2723 * The page queues must be locked.
2726 vm_page_free_wakeup(void)
2729 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2731 * if pageout daemon needs pages, then tell it that there are
2734 if (vm_pageout_pages_needed &&
2735 vm_cnt.v_free_count >= vm_cnt.v_pageout_free_min) {
2736 wakeup(&vm_pageout_pages_needed);
2737 vm_pageout_pages_needed = 0;
2740 * wakeup processes that are waiting on memory if we hit a
2741 * high water mark. And wakeup scheduler process if we have
2742 * lots of memory. this process will swapin processes.
2744 if (vm_pages_needed && !vm_page_count_min()) {
2745 vm_pages_needed = false;
2746 wakeup(&vm_cnt.v_free_count);
2753 * Returns the given page to the free list,
2754 * disassociating it with any VM object.
2756 * The object must be locked. The page must be locked if it is managed.
2759 vm_page_free_toq(vm_page_t m)
2762 if ((m->oflags & VPO_UNMANAGED) == 0) {
2763 vm_page_lock_assert(m, MA_OWNED);
2764 KASSERT(!pmap_page_is_mapped(m),
2765 ("vm_page_free_toq: freeing mapped page %p", m));
2767 KASSERT(m->queue == PQ_NONE,
2768 ("vm_page_free_toq: unmanaged page %p is queued", m));
2769 VM_CNT_INC(v_tfree);
2771 if (vm_page_sbusied(m))
2772 panic("vm_page_free: freeing busy page %p", m);
2775 * Unqueue, then remove page. Note that we cannot destroy
2776 * the page here because we do not want to call the pager's
2777 * callback routine until after we've put the page on the
2778 * appropriate free queue.
2784 * If fictitious remove object association and
2785 * return, otherwise delay object association removal.
2787 if ((m->flags & PG_FICTITIOUS) != 0) {
2794 if (m->wire_count != 0)
2795 panic("vm_page_free: freeing wired page %p", m);
2796 if (m->hold_count != 0) {
2797 m->flags &= ~PG_ZERO;
2798 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2799 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m));
2800 m->flags |= PG_UNHOLDFREE;
2803 * Restore the default memory attribute to the page.
2805 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
2806 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
2809 * Insert the page into the physical memory allocator's free
2812 mtx_lock(&vm_page_queue_free_mtx);
2813 vm_phys_freecnt_adj(m, 1);
2814 #if VM_NRESERVLEVEL > 0
2815 if (!vm_reserv_free_page(m))
2819 vm_phys_free_pages(m, 0);
2820 vm_page_free_wakeup();
2821 mtx_unlock(&vm_page_queue_free_mtx);
2828 * Mark this page as wired down by yet
2829 * another map, removing it from paging queues
2832 * If the page is fictitious, then its wire count must remain one.
2834 * The page must be locked.
2837 vm_page_wire(vm_page_t m)
2841 * Only bump the wire statistics if the page is not already wired,
2842 * and only unqueue the page if it is on some queue (if it is unmanaged
2843 * it is already off the queues).
2845 vm_page_lock_assert(m, MA_OWNED);
2846 if ((m->flags & PG_FICTITIOUS) != 0) {
2847 KASSERT(m->wire_count == 1,
2848 ("vm_page_wire: fictitious page %p's wire count isn't one",
2852 if (m->wire_count == 0) {
2853 KASSERT((m->oflags & VPO_UNMANAGED) == 0 ||
2854 m->queue == PQ_NONE,
2855 ("vm_page_wire: unmanaged page %p is queued", m));
2857 atomic_add_int(&vm_cnt.v_wire_count, 1);
2860 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
2866 * Release one wiring of the specified page, potentially allowing it to be
2867 * paged out. Returns TRUE if the number of wirings transitions to zero and
2870 * Only managed pages belonging to an object can be paged out. If the number
2871 * of wirings transitions to zero and the page is eligible for page out, then
2872 * the page is added to the specified paging queue (unless PQ_NONE is
2875 * If a page is fictitious, then its wire count must always be one.
2877 * A managed page must be locked.
2880 vm_page_unwire(vm_page_t m, uint8_t queue)
2883 KASSERT(queue < PQ_COUNT || queue == PQ_NONE,
2884 ("vm_page_unwire: invalid queue %u request for page %p",
2886 if ((m->oflags & VPO_UNMANAGED) == 0)
2887 vm_page_assert_locked(m);
2888 if ((m->flags & PG_FICTITIOUS) != 0) {
2889 KASSERT(m->wire_count == 1,
2890 ("vm_page_unwire: fictitious page %p's wire count isn't one", m));
2893 if (m->wire_count > 0) {
2895 if (m->wire_count == 0) {
2896 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
2897 if ((m->oflags & VPO_UNMANAGED) == 0 &&
2898 m->object != NULL && queue != PQ_NONE)
2899 vm_page_enqueue(queue, m);
2904 panic("vm_page_unwire: page %p's wire count is zero", m);
2908 * Move the specified page to the inactive queue.
2910 * Normally, "noreuse" is FALSE, resulting in LRU ordering of the inactive
2911 * queue. However, setting "noreuse" to TRUE will accelerate the specified
2912 * page's reclamation, but it will not unmap the page from any address space.
2913 * This is implemented by inserting the page near the head of the inactive
2914 * queue, using a marker page to guide FIFO insertion ordering.
2916 * The page must be locked.
2919 _vm_page_deactivate(vm_page_t m, boolean_t noreuse)
2921 struct vm_pagequeue *pq;
2924 vm_page_assert_locked(m);
2927 * Ignore if the page is already inactive, unless it is unlikely to be
2930 if ((queue = m->queue) == PQ_INACTIVE && !noreuse)
2932 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2933 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE];
2934 /* Avoid multiple acquisitions of the inactive queue lock. */
2935 if (queue == PQ_INACTIVE) {
2936 vm_pagequeue_lock(pq);
2937 vm_page_dequeue_locked(m);
2939 if (queue != PQ_NONE)
2941 vm_pagequeue_lock(pq);
2943 m->queue = PQ_INACTIVE;
2945 TAILQ_INSERT_BEFORE(&vm_phys_domain(m)->vmd_inacthead,
2948 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2949 vm_pagequeue_cnt_inc(pq);
2950 vm_pagequeue_unlock(pq);
2955 * Move the specified page to the inactive queue.
2957 * The page must be locked.
2960 vm_page_deactivate(vm_page_t m)
2963 _vm_page_deactivate(m, FALSE);
2967 * Move the specified page to the inactive queue with the expectation
2968 * that it is unlikely to be reused.
2970 * The page must be locked.
2973 vm_page_deactivate_noreuse(vm_page_t m)
2976 _vm_page_deactivate(m, TRUE);
2982 * Put a page in the laundry.
2985 vm_page_launder(vm_page_t m)
2989 vm_page_assert_locked(m);
2990 if ((queue = m->queue) != PQ_LAUNDRY) {
2991 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2992 if (queue != PQ_NONE)
2994 vm_page_enqueue(PQ_LAUNDRY, m);
2996 KASSERT(queue == PQ_NONE,
2997 ("wired page %p is queued", m));
3002 * vm_page_unswappable
3004 * Put a page in the PQ_UNSWAPPABLE holding queue.
3007 vm_page_unswappable(vm_page_t m)
3010 vm_page_assert_locked(m);
3011 KASSERT(m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0,
3012 ("page %p already unswappable", m));
3013 if (m->queue != PQ_NONE)
3015 vm_page_enqueue(PQ_UNSWAPPABLE, m);
3019 * vm_page_try_to_free()
3021 * Attempt to free the page. If we cannot free it, we do nothing.
3022 * 1 is returned on success, 0 on failure.
3025 vm_page_try_to_free(vm_page_t m)
3028 vm_page_lock_assert(m, MA_OWNED);
3029 if (m->object != NULL)
3030 VM_OBJECT_ASSERT_WLOCKED(m->object);
3031 if (m->dirty || m->hold_count || m->wire_count ||
3032 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m))
3044 * Apply the specified advice to the given page.
3046 * The object and page must be locked.
3049 vm_page_advise(vm_page_t m, int advice)
3052 vm_page_assert_locked(m);
3053 VM_OBJECT_ASSERT_WLOCKED(m->object);
3054 if (advice == MADV_FREE)
3056 * Mark the page clean. This will allow the page to be freed
3057 * without first paging it out. MADV_FREE pages are often
3058 * quickly reused by malloc(3), so we do not do anything that
3059 * would result in a page fault on a later access.
3062 else if (advice != MADV_DONTNEED) {
3063 if (advice == MADV_WILLNEED)
3064 vm_page_activate(m);
3069 * Clear any references to the page. Otherwise, the page daemon will
3070 * immediately reactivate the page.
3072 vm_page_aflag_clear(m, PGA_REFERENCED);
3074 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
3078 * Place clean pages near the head of the inactive queue rather than
3079 * the tail, thus defeating the queue's LRU operation and ensuring that
3080 * the page will be reused quickly. Dirty pages not already in the
3081 * laundry are moved there.
3084 vm_page_deactivate_noreuse(m);
3090 * Grab a page, waiting until we are waken up due to the page
3091 * changing state. We keep on waiting, if the page continues
3092 * to be in the object. If the page doesn't exist, first allocate it
3093 * and then conditionally zero it.
3095 * This routine may sleep.
3097 * The object must be locked on entry. The lock will, however, be released
3098 * and reacquired if the routine sleeps.
3101 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3106 VM_OBJECT_ASSERT_WLOCKED(object);
3107 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3108 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3109 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
3111 if ((m = vm_page_lookup(object, pindex)) != NULL) {
3112 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3113 vm_page_xbusied(m) : vm_page_busied(m);
3115 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3118 * Reference the page before unlocking and
3119 * sleeping so that the page daemon is less
3120 * likely to reclaim it.
3122 vm_page_aflag_set(m, PGA_REFERENCED);
3124 VM_OBJECT_WUNLOCK(object);
3125 vm_page_busy_sleep(m, "pgrbwt", (allocflags &
3126 VM_ALLOC_IGN_SBUSY) != 0);
3127 VM_OBJECT_WLOCK(object);
3130 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3136 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
3138 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3143 m = vm_page_alloc(object, pindex, allocflags);
3145 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3147 VM_OBJECT_WUNLOCK(object);
3149 VM_OBJECT_WLOCK(object);
3152 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
3158 * Mapping function for valid or dirty bits in a page.
3160 * Inputs are required to range within a page.
3163 vm_page_bits(int base, int size)
3169 base + size <= PAGE_SIZE,
3170 ("vm_page_bits: illegal base/size %d/%d", base, size)
3173 if (size == 0) /* handle degenerate case */
3176 first_bit = base >> DEV_BSHIFT;
3177 last_bit = (base + size - 1) >> DEV_BSHIFT;
3179 return (((vm_page_bits_t)2 << last_bit) -
3180 ((vm_page_bits_t)1 << first_bit));
3184 * vm_page_set_valid_range:
3186 * Sets portions of a page valid. The arguments are expected
3187 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3188 * of any partial chunks touched by the range. The invalid portion of
3189 * such chunks will be zeroed.
3191 * (base + size) must be less then or equal to PAGE_SIZE.
3194 vm_page_set_valid_range(vm_page_t m, int base, int size)
3198 VM_OBJECT_ASSERT_WLOCKED(m->object);
3199 if (size == 0) /* handle degenerate case */
3203 * If the base is not DEV_BSIZE aligned and the valid
3204 * bit is clear, we have to zero out a portion of the
3207 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3208 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
3209 pmap_zero_page_area(m, frag, base - frag);
3212 * If the ending offset is not DEV_BSIZE aligned and the
3213 * valid bit is clear, we have to zero out a portion of
3216 endoff = base + size;
3217 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3218 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
3219 pmap_zero_page_area(m, endoff,
3220 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3223 * Assert that no previously invalid block that is now being validated
3226 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
3227 ("vm_page_set_valid_range: page %p is dirty", m));
3230 * Set valid bits inclusive of any overlap.
3232 m->valid |= vm_page_bits(base, size);
3236 * Clear the given bits from the specified page's dirty field.
3238 static __inline void
3239 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
3242 #if PAGE_SIZE < 16384
3247 * If the object is locked and the page is neither exclusive busy nor
3248 * write mapped, then the page's dirty field cannot possibly be
3249 * set by a concurrent pmap operation.
3251 VM_OBJECT_ASSERT_WLOCKED(m->object);
3252 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
3253 m->dirty &= ~pagebits;
3256 * The pmap layer can call vm_page_dirty() without
3257 * holding a distinguished lock. The combination of
3258 * the object's lock and an atomic operation suffice
3259 * to guarantee consistency of the page dirty field.
3261 * For PAGE_SIZE == 32768 case, compiler already
3262 * properly aligns the dirty field, so no forcible
3263 * alignment is needed. Only require existence of
3264 * atomic_clear_64 when page size is 32768.
3266 addr = (uintptr_t)&m->dirty;
3267 #if PAGE_SIZE == 32768
3268 atomic_clear_64((uint64_t *)addr, pagebits);
3269 #elif PAGE_SIZE == 16384
3270 atomic_clear_32((uint32_t *)addr, pagebits);
3271 #else /* PAGE_SIZE <= 8192 */
3273 * Use a trick to perform a 32-bit atomic on the
3274 * containing aligned word, to not depend on the existence
3275 * of atomic_clear_{8, 16}.
3277 shift = addr & (sizeof(uint32_t) - 1);
3278 #if BYTE_ORDER == BIG_ENDIAN
3279 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
3283 addr &= ~(sizeof(uint32_t) - 1);
3284 atomic_clear_32((uint32_t *)addr, pagebits << shift);
3285 #endif /* PAGE_SIZE */
3290 * vm_page_set_validclean:
3292 * Sets portions of a page valid and clean. The arguments are expected
3293 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3294 * of any partial chunks touched by the range. The invalid portion of
3295 * such chunks will be zero'd.
3297 * (base + size) must be less then or equal to PAGE_SIZE.
3300 vm_page_set_validclean(vm_page_t m, int base, int size)
3302 vm_page_bits_t oldvalid, pagebits;
3305 VM_OBJECT_ASSERT_WLOCKED(m->object);
3306 if (size == 0) /* handle degenerate case */
3310 * If the base is not DEV_BSIZE aligned and the valid
3311 * bit is clear, we have to zero out a portion of the
3314 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3315 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
3316 pmap_zero_page_area(m, frag, base - frag);
3319 * If the ending offset is not DEV_BSIZE aligned and the
3320 * valid bit is clear, we have to zero out a portion of
3323 endoff = base + size;
3324 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3325 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
3326 pmap_zero_page_area(m, endoff,
3327 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3330 * Set valid, clear dirty bits. If validating the entire
3331 * page we can safely clear the pmap modify bit. We also
3332 * use this opportunity to clear the VPO_NOSYNC flag. If a process
3333 * takes a write fault on a MAP_NOSYNC memory area the flag will
3336 * We set valid bits inclusive of any overlap, but we can only
3337 * clear dirty bits for DEV_BSIZE chunks that are fully within
3340 oldvalid = m->valid;
3341 pagebits = vm_page_bits(base, size);
3342 m->valid |= pagebits;
3344 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
3345 frag = DEV_BSIZE - frag;
3351 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
3353 if (base == 0 && size == PAGE_SIZE) {
3355 * The page can only be modified within the pmap if it is
3356 * mapped, and it can only be mapped if it was previously
3359 if (oldvalid == VM_PAGE_BITS_ALL)
3361 * Perform the pmap_clear_modify() first. Otherwise,
3362 * a concurrent pmap operation, such as
3363 * pmap_protect(), could clear a modification in the
3364 * pmap and set the dirty field on the page before
3365 * pmap_clear_modify() had begun and after the dirty
3366 * field was cleared here.
3368 pmap_clear_modify(m);
3370 m->oflags &= ~VPO_NOSYNC;
3371 } else if (oldvalid != VM_PAGE_BITS_ALL)
3372 m->dirty &= ~pagebits;
3374 vm_page_clear_dirty_mask(m, pagebits);
3378 vm_page_clear_dirty(vm_page_t m, int base, int size)
3381 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
3385 * vm_page_set_invalid:
3387 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3388 * valid and dirty bits for the effected areas are cleared.
3391 vm_page_set_invalid(vm_page_t m, int base, int size)
3393 vm_page_bits_t bits;
3397 VM_OBJECT_ASSERT_WLOCKED(object);
3398 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
3399 size >= object->un_pager.vnp.vnp_size)
3400 bits = VM_PAGE_BITS_ALL;
3402 bits = vm_page_bits(base, size);
3403 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL &&
3406 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
3407 !pmap_page_is_mapped(m),
3408 ("vm_page_set_invalid: page %p is mapped", m));
3414 * vm_page_zero_invalid()
3416 * The kernel assumes that the invalid portions of a page contain
3417 * garbage, but such pages can be mapped into memory by user code.
3418 * When this occurs, we must zero out the non-valid portions of the
3419 * page so user code sees what it expects.
3421 * Pages are most often semi-valid when the end of a file is mapped
3422 * into memory and the file's size is not page aligned.
3425 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3430 VM_OBJECT_ASSERT_WLOCKED(m->object);
3432 * Scan the valid bits looking for invalid sections that
3433 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
3434 * valid bit may be set ) have already been zeroed by
3435 * vm_page_set_validclean().
3437 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3438 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3439 (m->valid & ((vm_page_bits_t)1 << i))) {
3441 pmap_zero_page_area(m,
3442 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
3449 * setvalid is TRUE when we can safely set the zero'd areas
3450 * as being valid. We can do this if there are no cache consistancy
3451 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3454 m->valid = VM_PAGE_BITS_ALL;
3460 * Is (partial) page valid? Note that the case where size == 0
3461 * will return FALSE in the degenerate case where the page is
3462 * entirely invalid, and TRUE otherwise.
3465 vm_page_is_valid(vm_page_t m, int base, int size)
3467 vm_page_bits_t bits;
3469 VM_OBJECT_ASSERT_LOCKED(m->object);
3470 bits = vm_page_bits(base, size);
3471 return (m->valid != 0 && (m->valid & bits) == bits);
3475 * vm_page_ps_is_valid:
3477 * Returns TRUE if the entire (super)page is valid and FALSE otherwise.
3480 vm_page_ps_is_valid(vm_page_t m)
3484 VM_OBJECT_ASSERT_LOCKED(m->object);
3485 npages = atop(pagesizes[m->psind]);
3488 * The physically contiguous pages that make up a superpage, i.e., a
3489 * page with a page size index ("psind") greater than zero, will
3490 * occupy adjacent entries in vm_page_array[].
3492 for (i = 0; i < npages; i++) {
3493 if (m[i].valid != VM_PAGE_BITS_ALL)
3500 * Set the page's dirty bits if the page is modified.
3503 vm_page_test_dirty(vm_page_t m)
3506 VM_OBJECT_ASSERT_WLOCKED(m->object);
3507 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
3512 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
3515 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
3519 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
3522 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
3526 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
3529 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
3532 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
3534 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
3537 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
3541 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
3544 mtx_assert_(vm_page_lockptr(m), a, file, line);
3550 vm_page_object_lock_assert(vm_page_t m)
3554 * Certain of the page's fields may only be modified by the
3555 * holder of the containing object's lock or the exclusive busy.
3556 * holder. Unfortunately, the holder of the write busy is
3557 * not recorded, and thus cannot be checked here.
3559 if (m->object != NULL && !vm_page_xbusied(m))
3560 VM_OBJECT_ASSERT_WLOCKED(m->object);
3564 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits)
3567 if ((bits & PGA_WRITEABLE) == 0)
3571 * The PGA_WRITEABLE flag can only be set if the page is
3572 * managed, is exclusively busied or the object is locked.
3573 * Currently, this flag is only set by pmap_enter().
3575 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3576 ("PGA_WRITEABLE on unmanaged page"));
3577 if (!vm_page_xbusied(m))
3578 VM_OBJECT_ASSERT_LOCKED(m->object);
3582 #include "opt_ddb.h"
3584 #include <sys/kernel.h>
3586 #include <ddb/ddb.h>
3588 DB_SHOW_COMMAND(page, vm_page_print_page_info)
3591 db_printf("vm_cnt.v_free_count: %d\n", vm_cnt.v_free_count);
3592 db_printf("vm_cnt.v_inactive_count: %d\n", vm_cnt.v_inactive_count);
3593 db_printf("vm_cnt.v_active_count: %d\n", vm_cnt.v_active_count);
3594 db_printf("vm_cnt.v_laundry_count: %d\n", vm_cnt.v_laundry_count);
3595 db_printf("vm_cnt.v_wire_count: %d\n", vm_cnt.v_wire_count);
3596 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
3597 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
3598 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
3599 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
3602 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
3606 db_printf("pq_free %d\n", vm_cnt.v_free_count);
3607 for (dom = 0; dom < vm_ndomains; dom++) {
3609 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
3611 vm_dom[dom].vmd_page_count,
3612 vm_dom[dom].vmd_free_count,
3613 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
3614 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
3615 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
3616 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
3620 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
3626 db_printf("show pginfo addr\n");
3630 phys = strchr(modif, 'p') != NULL;
3632 m = PHYS_TO_VM_PAGE(addr);
3634 m = (vm_page_t)addr;
3636 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n"
3637 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
3638 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
3639 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags,
3640 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);