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/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];
134 vm_page_t vm_page_array;
135 long vm_page_array_size;
138 static int boot_pages = UMA_BOOT_PAGES;
139 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
141 "number of pages allocated for bootstrapping the VM system");
143 static int pa_tryrelock_restart;
144 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
145 &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
147 static TAILQ_HEAD(, vm_page) blacklist_head;
148 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
149 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
150 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
152 /* Is the page daemon waiting for free pages? */
153 static int vm_pageout_pages_needed;
155 static uma_zone_t fakepg_zone;
157 static struct vnode *vm_page_alloc_init(vm_page_t m);
158 static void vm_page_cache_turn_free(vm_page_t m);
159 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
160 static void vm_page_enqueue(uint8_t queue, vm_page_t m);
161 static void vm_page_free_wakeup(void);
162 static void vm_page_init_fakepg(void *dummy);
163 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
164 vm_pindex_t pindex, vm_page_t mpred);
165 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
167 static int vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
170 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init_fakepg, NULL);
173 vm_page_init_fakepg(void *dummy)
176 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
177 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
180 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
181 #if PAGE_SIZE == 32768
183 CTASSERT(sizeof(u_long) >= 8);
188 * Try to acquire a physical address lock while a pmap is locked. If we
189 * fail to trylock we unlock and lock the pmap directly and cache the
190 * locked pa in *locked. The caller should then restart their loop in case
191 * the virtual to physical mapping has changed.
194 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
201 PA_LOCK_ASSERT(lockpa, MA_OWNED);
202 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
209 atomic_add_int(&pa_tryrelock_restart, 1);
218 * Sets the page size, perhaps based upon the memory
219 * size. Must be called before any use of page-size
220 * dependent functions.
223 vm_set_page_size(void)
225 if (vm_cnt.v_page_size == 0)
226 vm_cnt.v_page_size = PAGE_SIZE;
227 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
228 panic("vm_set_page_size: page size not a power of two");
232 * vm_page_blacklist_next:
234 * Find the next entry in the provided string of blacklist
235 * addresses. Entries are separated by space, comma, or newline.
236 * If an invalid integer is encountered then the rest of the
237 * string is skipped. Updates the list pointer to the next
238 * character, or NULL if the string is exhausted or invalid.
241 vm_page_blacklist_next(char **list, char *end)
246 if (list == NULL || *list == NULL)
254 * If there's no end pointer then the buffer is coming from
255 * the kenv and we know it's null-terminated.
258 end = *list + strlen(*list);
260 /* Ensure that strtoq() won't walk off the end */
262 if (*end == '\n' || *end == ' ' || *end == ',')
265 printf("Blacklist not terminated, skipping\n");
271 for (pos = *list; *pos != '\0'; pos = cp) {
272 bad = strtoq(pos, &cp, 0);
273 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
282 if (*cp == '\0' || ++cp >= end)
286 return (trunc_page(bad));
288 printf("Garbage in RAM blacklist, skipping\n");
294 * vm_page_blacklist_check:
296 * Iterate through the provided string of blacklist addresses, pulling
297 * each entry out of the physical allocator free list and putting it
298 * onto a list for reporting via the vm.page_blacklist sysctl.
301 vm_page_blacklist_check(char *list, char *end)
309 while (next != NULL) {
310 if ((pa = vm_page_blacklist_next(&next, end)) == 0)
312 m = vm_phys_paddr_to_vm_page(pa);
315 mtx_lock(&vm_page_queue_free_mtx);
316 ret = vm_phys_unfree_page(m);
317 mtx_unlock(&vm_page_queue_free_mtx);
319 TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
321 printf("Skipping page with pa 0x%jx\n",
328 * vm_page_blacklist_load:
330 * Search for a special module named "ram_blacklist". It'll be a
331 * plain text file provided by the user via the loader directive
335 vm_page_blacklist_load(char **list, char **end)
344 mod = preload_search_by_type("ram_blacklist");
346 ptr = preload_fetch_addr(mod);
347 len = preload_fetch_size(mod);
358 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
365 error = sysctl_wire_old_buffer(req, 0);
368 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
369 TAILQ_FOREACH(m, &blacklist_head, listq) {
370 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
371 (uintmax_t)m->phys_addr);
374 error = sbuf_finish(&sbuf);
380 vm_page_domain_init(struct vm_domain *vmd)
382 struct vm_pagequeue *pq;
385 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
386 "vm inactive pagequeue";
387 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) =
388 &vm_cnt.v_inactive_count;
389 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
390 "vm active pagequeue";
391 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) =
392 &vm_cnt.v_active_count;
393 vmd->vmd_page_count = 0;
394 vmd->vmd_free_count = 0;
396 vmd->vmd_oom = FALSE;
398 for (i = 0; i < PQ_COUNT; i++) {
399 pq = &vmd->vmd_pagequeues[i];
400 TAILQ_INIT(&pq->pq_pl);
401 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
402 MTX_DEF | MTX_DUPOK);
409 * Initializes the resident memory module.
411 * Allocates memory for the page cells, and
412 * for the object/offset-to-page hash table headers.
413 * Each page cell is initialized and placed on the free list.
416 vm_page_startup(vm_offset_t vaddr)
419 vm_paddr_t page_range;
424 char *list, *listend;
426 vm_paddr_t biggestsize;
427 vm_paddr_t low_water, high_water;
433 vaddr = round_page(vaddr);
435 for (i = 0; phys_avail[i + 1]; i += 2) {
436 phys_avail[i] = round_page(phys_avail[i]);
437 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
440 low_water = phys_avail[0];
441 high_water = phys_avail[1];
443 for (i = 0; i < vm_phys_nsegs; i++) {
444 if (vm_phys_segs[i].start < low_water)
445 low_water = vm_phys_segs[i].start;
446 if (vm_phys_segs[i].end > high_water)
447 high_water = vm_phys_segs[i].end;
449 for (i = 0; phys_avail[i + 1]; i += 2) {
450 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i];
452 if (size > biggestsize) {
456 if (phys_avail[i] < low_water)
457 low_water = phys_avail[i];
458 if (phys_avail[i + 1] > high_water)
459 high_water = phys_avail[i + 1];
462 end = phys_avail[biggestone+1];
465 * Initialize the page and queue locks.
467 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF);
468 for (i = 0; i < PA_LOCK_COUNT; i++)
469 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
470 for (i = 0; i < vm_ndomains; i++)
471 vm_page_domain_init(&vm_dom[i]);
474 * Almost all of the pages needed for boot strapping UMA are used
475 * for zone structures, so if the number of CPUs results in those
476 * structures taking more than one page each, we set aside more pages
477 * in proportion to the zone structure size.
479 pages_per_zone = howmany(sizeof(struct uma_zone) +
480 sizeof(struct uma_cache) * (mp_maxid + 1), UMA_SLAB_SIZE);
481 if (pages_per_zone > 1) {
482 /* Reserve more pages so that we don't run out. */
483 boot_pages = UMA_BOOT_PAGES_ZONES * pages_per_zone;
487 * Allocate memory for use when boot strapping the kernel memory
490 * CTFLAG_RDTUN doesn't work during the early boot process, so we must
491 * manually fetch the value.
493 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages);
494 new_end = end - (boot_pages * UMA_SLAB_SIZE);
495 new_end = trunc_page(new_end);
496 mapped = pmap_map(&vaddr, new_end, end,
497 VM_PROT_READ | VM_PROT_WRITE);
498 bzero((void *)mapped, end - new_end);
499 uma_startup((void *)mapped, boot_pages);
501 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
502 defined(__i386__) || defined(__mips__)
504 * Allocate a bitmap to indicate that a random physical page
505 * needs to be included in a minidump.
507 * The amd64 port needs this to indicate which direct map pages
508 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
510 * However, i386 still needs this workspace internally within the
511 * minidump code. In theory, they are not needed on i386, but are
512 * included should the sf_buf code decide to use them.
515 for (i = 0; dump_avail[i + 1] != 0; i += 2)
516 if (dump_avail[i + 1] > last_pa)
517 last_pa = dump_avail[i + 1];
518 page_range = last_pa / PAGE_SIZE;
519 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
520 new_end -= vm_page_dump_size;
521 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
522 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
523 bzero((void *)vm_page_dump, vm_page_dump_size);
527 * Request that the physical pages underlying the message buffer be
528 * included in a crash dump. Since the message buffer is accessed
529 * through the direct map, they are not automatically included.
531 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
532 last_pa = pa + round_page(msgbufsize);
533 while (pa < last_pa) {
539 * Compute the number of pages of memory that will be available for
540 * use (taking into account the overhead of a page structure per
543 first_page = low_water / PAGE_SIZE;
544 #ifdef VM_PHYSSEG_SPARSE
546 for (i = 0; i < vm_phys_nsegs; i++) {
547 page_range += atop(vm_phys_segs[i].end -
548 vm_phys_segs[i].start);
550 for (i = 0; phys_avail[i + 1] != 0; i += 2)
551 page_range += atop(phys_avail[i + 1] - phys_avail[i]);
552 #elif defined(VM_PHYSSEG_DENSE)
553 page_range = high_water / PAGE_SIZE - first_page;
555 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
560 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
565 * Initialize the mem entry structures now, and put them in the free
568 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
569 mapped = pmap_map(&vaddr, new_end, end,
570 VM_PROT_READ | VM_PROT_WRITE);
571 vm_page_array = (vm_page_t) mapped;
572 #if VM_NRESERVLEVEL > 0
574 * Allocate memory for the reservation management system's data
577 new_end = vm_reserv_startup(&vaddr, new_end, high_water);
579 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
581 * pmap_map on arm64, amd64, and mips can come out of the direct-map,
582 * not kvm like i386, so the pages must be tracked for a crashdump to
583 * include this data. This includes the vm_page_array and the early
584 * UMA bootstrap pages.
586 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
589 phys_avail[biggestone + 1] = new_end;
592 * Add physical memory segments corresponding to the available
595 for (i = 0; phys_avail[i + 1] != 0; i += 2)
596 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
599 * Clear all of the page structures
601 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
602 for (i = 0; i < page_range; i++)
603 vm_page_array[i].order = VM_NFREEORDER;
604 vm_page_array_size = page_range;
607 * Initialize the physical memory allocator.
612 * Add every available physical page that is not blacklisted to
615 vm_cnt.v_page_count = 0;
616 vm_cnt.v_free_count = 0;
617 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
619 last_pa = phys_avail[i + 1];
620 while (pa < last_pa) {
621 vm_phys_add_page(pa);
626 TAILQ_INIT(&blacklist_head);
627 vm_page_blacklist_load(&list, &listend);
628 vm_page_blacklist_check(list, listend);
630 list = kern_getenv("vm.blacklist");
631 vm_page_blacklist_check(list, NULL);
634 #if VM_NRESERVLEVEL > 0
636 * Initialize the reservation management system.
644 vm_page_reference(vm_page_t m)
647 vm_page_aflag_set(m, PGA_REFERENCED);
651 * vm_page_busy_downgrade:
653 * Downgrade an exclusive busy page into a single shared busy page.
656 vm_page_busy_downgrade(vm_page_t m)
660 vm_page_assert_xbusied(m);
664 x &= VPB_BIT_WAITERS;
665 if (atomic_cmpset_rel_int(&m->busy_lock,
666 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1) | x))
674 * Return a positive value if the page is shared busied, 0 otherwise.
677 vm_page_sbusied(vm_page_t m)
682 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
688 * Shared unbusy a page.
691 vm_page_sunbusy(vm_page_t m)
695 vm_page_assert_sbusied(m);
699 if (VPB_SHARERS(x) > 1) {
700 if (atomic_cmpset_int(&m->busy_lock, x,
705 if ((x & VPB_BIT_WAITERS) == 0) {
706 KASSERT(x == VPB_SHARERS_WORD(1),
707 ("vm_page_sunbusy: invalid lock state"));
708 if (atomic_cmpset_int(&m->busy_lock,
709 VPB_SHARERS_WORD(1), VPB_UNBUSIED))
713 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS),
714 ("vm_page_sunbusy: invalid lock state for waiters"));
717 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) {
728 * vm_page_busy_sleep:
730 * Sleep and release the page lock, using the page pointer as wchan.
731 * This is used to implement the hard-path of busying mechanism.
733 * The given page must be locked.
736 vm_page_busy_sleep(vm_page_t m, const char *wmesg)
740 vm_page_lock_assert(m, MA_OWNED);
743 if (x == VPB_UNBUSIED) {
747 if ((x & VPB_BIT_WAITERS) == 0 &&
748 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS)) {
752 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0);
758 * Try to shared busy a page.
759 * If the operation succeeds 1 is returned otherwise 0.
760 * The operation never sleeps.
763 vm_page_trysbusy(vm_page_t m)
769 if ((x & VPB_BIT_SHARED) == 0)
771 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER))
777 vm_page_xunbusy_locked(vm_page_t m)
780 vm_page_assert_xbusied(m);
781 vm_page_assert_locked(m);
783 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
784 /* There is a waiter, do wakeup() instead of vm_page_flash(). */
789 vm_page_xunbusy_maybelocked(vm_page_t m)
793 vm_page_assert_xbusied(m);
796 * Fast path for unbusy. If it succeeds, we know that there
797 * are no waiters, so we do not need a wakeup.
799 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER,
803 lockacq = !mtx_owned(vm_page_lockptr(m));
806 vm_page_xunbusy_locked(m);
812 * vm_page_xunbusy_hard:
814 * Called after the first try the exclusive unbusy of a page failed.
815 * It is assumed that the waiters bit is on.
818 vm_page_xunbusy_hard(vm_page_t m)
821 vm_page_assert_xbusied(m);
824 vm_page_xunbusy_locked(m);
831 * Wakeup anyone waiting for the page.
832 * The ownership bits do not change.
834 * The given page must be locked.
837 vm_page_flash(vm_page_t m)
841 vm_page_lock_assert(m, MA_OWNED);
845 if ((x & VPB_BIT_WAITERS) == 0)
847 if (atomic_cmpset_int(&m->busy_lock, x,
848 x & (~VPB_BIT_WAITERS)))
855 * Keep page from being freed by the page daemon
856 * much of the same effect as wiring, except much lower
857 * overhead and should be used only for *very* temporary
858 * holding ("wiring").
861 vm_page_hold(vm_page_t mem)
864 vm_page_lock_assert(mem, MA_OWNED);
869 vm_page_unhold(vm_page_t mem)
872 vm_page_lock_assert(mem, MA_OWNED);
873 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!"));
875 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0)
876 vm_page_free_toq(mem);
880 * vm_page_unhold_pages:
882 * Unhold each of the pages that is referenced by the given array.
885 vm_page_unhold_pages(vm_page_t *ma, int count)
887 struct mtx *mtx, *new_mtx;
890 for (; count != 0; count--) {
892 * Avoid releasing and reacquiring the same page lock.
894 new_mtx = vm_page_lockptr(*ma);
895 if (mtx != new_mtx) {
909 PHYS_TO_VM_PAGE(vm_paddr_t pa)
913 #ifdef VM_PHYSSEG_SPARSE
914 m = vm_phys_paddr_to_vm_page(pa);
916 m = vm_phys_fictitious_to_vm_page(pa);
918 #elif defined(VM_PHYSSEG_DENSE)
922 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
923 m = &vm_page_array[pi - first_page];
926 return (vm_phys_fictitious_to_vm_page(pa));
928 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
935 * Create a fictitious page with the specified physical address and
936 * memory attribute. The memory attribute is the only the machine-
937 * dependent aspect of a fictitious page that must be initialized.
940 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
944 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
945 vm_page_initfake(m, paddr, memattr);
950 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
953 if ((m->flags & PG_FICTITIOUS) != 0) {
955 * The page's memattr might have changed since the
956 * previous initialization. Update the pmap to the
961 m->phys_addr = paddr;
963 /* Fictitious pages don't use "segind". */
964 m->flags = PG_FICTITIOUS;
965 /* Fictitious pages don't use "order" or "pool". */
966 m->oflags = VPO_UNMANAGED;
967 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
971 pmap_page_set_memattr(m, memattr);
977 * Release a fictitious page.
980 vm_page_putfake(vm_page_t m)
983 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
984 KASSERT((m->flags & PG_FICTITIOUS) != 0,
985 ("vm_page_putfake: bad page %p", m));
986 uma_zfree(fakepg_zone, m);
990 * vm_page_updatefake:
992 * Update the given fictitious page to the specified physical address and
996 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
999 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1000 ("vm_page_updatefake: bad page %p", m));
1001 m->phys_addr = paddr;
1002 pmap_page_set_memattr(m, memattr);
1011 vm_page_free(vm_page_t m)
1014 m->flags &= ~PG_ZERO;
1015 vm_page_free_toq(m);
1019 * vm_page_free_zero:
1021 * Free a page to the zerod-pages queue
1024 vm_page_free_zero(vm_page_t m)
1027 m->flags |= PG_ZERO;
1028 vm_page_free_toq(m);
1032 * Unbusy and handle the page queueing for a page from a getpages request that
1033 * was optionally read ahead or behind.
1036 vm_page_readahead_finish(vm_page_t m)
1039 /* We shouldn't put invalid pages on queues. */
1040 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
1043 * Since the page is not the actually needed one, whether it should
1044 * be activated or deactivated is not obvious. Empirical results
1045 * have shown that deactivating the page is usually the best choice,
1046 * unless the page is wanted by another thread.
1049 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
1050 vm_page_activate(m);
1052 vm_page_deactivate(m);
1058 * vm_page_sleep_if_busy:
1060 * Sleep and release the page queues lock if the page is busied.
1061 * Returns TRUE if the thread slept.
1063 * The given page must be unlocked and object containing it must
1067 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
1071 vm_page_lock_assert(m, MA_NOTOWNED);
1072 VM_OBJECT_ASSERT_WLOCKED(m->object);
1074 if (vm_page_busied(m)) {
1076 * The page-specific object must be cached because page
1077 * identity can change during the sleep, causing the
1078 * re-lock of a different object.
1079 * It is assumed that a reference to the object is already
1080 * held by the callers.
1084 VM_OBJECT_WUNLOCK(obj);
1085 vm_page_busy_sleep(m, msg);
1086 VM_OBJECT_WLOCK(obj);
1093 * vm_page_dirty_KBI: [ internal use only ]
1095 * Set all bits in the page's dirty field.
1097 * The object containing the specified page must be locked if the
1098 * call is made from the machine-independent layer.
1100 * See vm_page_clear_dirty_mask().
1102 * This function should only be called by vm_page_dirty().
1105 vm_page_dirty_KBI(vm_page_t m)
1108 /* These assertions refer to this operation by its public name. */
1109 KASSERT((m->flags & PG_CACHED) == 0,
1110 ("vm_page_dirty: page in cache!"));
1111 KASSERT(m->valid == VM_PAGE_BITS_ALL,
1112 ("vm_page_dirty: page is invalid!"));
1113 m->dirty = VM_PAGE_BITS_ALL;
1117 * vm_page_insert: [ internal use only ]
1119 * Inserts the given mem entry into the object and object list.
1121 * The object must be locked.
1124 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1128 VM_OBJECT_ASSERT_WLOCKED(object);
1129 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1130 return (vm_page_insert_after(m, object, pindex, mpred));
1134 * vm_page_insert_after:
1136 * Inserts the page "m" into the specified object at offset "pindex".
1138 * The page "mpred" must immediately precede the offset "pindex" within
1139 * the specified object.
1141 * The object must be locked.
1144 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1149 VM_OBJECT_ASSERT_WLOCKED(object);
1150 KASSERT(m->object == NULL,
1151 ("vm_page_insert_after: page already inserted"));
1152 if (mpred != NULL) {
1153 KASSERT(mpred->object == object,
1154 ("vm_page_insert_after: object doesn't contain mpred"));
1155 KASSERT(mpred->pindex < pindex,
1156 ("vm_page_insert_after: mpred doesn't precede pindex"));
1157 msucc = TAILQ_NEXT(mpred, listq);
1159 msucc = TAILQ_FIRST(&object->memq);
1161 KASSERT(msucc->pindex > pindex,
1162 ("vm_page_insert_after: msucc doesn't succeed pindex"));
1165 * Record the object/offset pair in this page
1171 * Now link into the object's ordered list of backed pages.
1173 if (vm_radix_insert(&object->rtree, m)) {
1178 vm_page_insert_radixdone(m, object, mpred);
1183 * vm_page_insert_radixdone:
1185 * Complete page "m" insertion into the specified object after the
1186 * radix trie hooking.
1188 * The page "mpred" must precede the offset "m->pindex" within the
1191 * The object must be locked.
1194 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1197 VM_OBJECT_ASSERT_WLOCKED(object);
1198 KASSERT(object != NULL && m->object == object,
1199 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1200 if (mpred != NULL) {
1201 KASSERT(mpred->object == object,
1202 ("vm_page_insert_after: object doesn't contain mpred"));
1203 KASSERT(mpred->pindex < m->pindex,
1204 ("vm_page_insert_after: mpred doesn't precede pindex"));
1208 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1210 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1213 * Show that the object has one more resident page.
1215 object->resident_page_count++;
1218 * Hold the vnode until the last page is released.
1220 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1221 vhold(object->handle);
1224 * Since we are inserting a new and possibly dirty page,
1225 * update the object's OBJ_MIGHTBEDIRTY flag.
1227 if (pmap_page_is_write_mapped(m))
1228 vm_object_set_writeable_dirty(object);
1234 * Removes the given mem entry from the object/offset-page
1235 * table and the object page list, but do not invalidate/terminate
1236 * the backing store.
1238 * The object must be locked. The page must be locked if it is managed.
1241 vm_page_remove(vm_page_t m)
1245 if ((m->oflags & VPO_UNMANAGED) == 0)
1246 vm_page_assert_locked(m);
1247 if ((object = m->object) == NULL)
1249 VM_OBJECT_ASSERT_WLOCKED(object);
1250 if (vm_page_xbusied(m))
1251 vm_page_xunbusy_maybelocked(m);
1254 * Now remove from the object's list of backed pages.
1256 vm_radix_remove(&object->rtree, m->pindex);
1257 TAILQ_REMOVE(&object->memq, m, listq);
1260 * And show that the object has one fewer resident page.
1262 object->resident_page_count--;
1265 * The vnode may now be recycled.
1267 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1268 vdrop(object->handle);
1276 * Returns the page associated with the object/offset
1277 * pair specified; if none is found, NULL is returned.
1279 * The object must be locked.
1282 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1285 VM_OBJECT_ASSERT_LOCKED(object);
1286 return (vm_radix_lookup(&object->rtree, pindex));
1290 * vm_page_find_least:
1292 * Returns the page associated with the object with least pindex
1293 * greater than or equal to the parameter pindex, or NULL.
1295 * The object must be locked.
1298 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1302 VM_OBJECT_ASSERT_LOCKED(object);
1303 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1304 m = vm_radix_lookup_ge(&object->rtree, pindex);
1309 * Returns the given page's successor (by pindex) within the object if it is
1310 * resident; if none is found, NULL is returned.
1312 * The object must be locked.
1315 vm_page_next(vm_page_t m)
1319 VM_OBJECT_ASSERT_LOCKED(m->object);
1320 if ((next = TAILQ_NEXT(m, listq)) != NULL &&
1321 next->pindex != m->pindex + 1)
1327 * Returns the given page's predecessor (by pindex) within the object if it is
1328 * resident; if none is found, NULL is returned.
1330 * The object must be locked.
1333 vm_page_prev(vm_page_t m)
1337 VM_OBJECT_ASSERT_LOCKED(m->object);
1338 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL &&
1339 prev->pindex != m->pindex - 1)
1345 * Uses the page mnew as a replacement for an existing page at index
1346 * pindex which must be already present in the object.
1348 * The existing page must not be on a paging queue.
1351 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1355 VM_OBJECT_ASSERT_WLOCKED(object);
1356 KASSERT(mnew->object == NULL,
1357 ("vm_page_replace: page already in object"));
1360 * This function mostly follows vm_page_insert() and
1361 * vm_page_remove() without the radix, object count and vnode
1362 * dance. Double check such functions for more comments.
1365 mnew->object = object;
1366 mnew->pindex = pindex;
1367 mold = vm_radix_replace(&object->rtree, mnew);
1368 KASSERT(mold->queue == PQ_NONE,
1369 ("vm_page_replace: mold is on a paging queue"));
1371 /* Keep the resident page list in sorted order. */
1372 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1373 TAILQ_REMOVE(&object->memq, mold, listq);
1375 mold->object = NULL;
1376 vm_page_xunbusy_maybelocked(mold);
1379 * The object's resident_page_count does not change because we have
1380 * swapped one page for another, but OBJ_MIGHTBEDIRTY.
1382 if (pmap_page_is_write_mapped(mnew))
1383 vm_object_set_writeable_dirty(object);
1390 * Move the given memory entry from its
1391 * current object to the specified target object/offset.
1393 * Note: swap associated with the page must be invalidated by the move. We
1394 * have to do this for several reasons: (1) we aren't freeing the
1395 * page, (2) we are dirtying the page, (3) the VM system is probably
1396 * moving the page from object A to B, and will then later move
1397 * the backing store from A to B and we can't have a conflict.
1399 * Note: we *always* dirty the page. It is necessary both for the
1400 * fact that we moved it, and because we may be invalidating
1401 * swap. If the page is on the cache, we have to deactivate it
1402 * or vm_page_dirty() will panic. Dirty pages are not allowed
1405 * The objects must be locked.
1408 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1413 VM_OBJECT_ASSERT_WLOCKED(new_object);
1415 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1416 KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1417 ("vm_page_rename: pindex already renamed"));
1420 * Create a custom version of vm_page_insert() which does not depend
1421 * by m_prev and can cheat on the implementation aspects of the
1425 m->pindex = new_pindex;
1426 if (vm_radix_insert(&new_object->rtree, m)) {
1432 * The operation cannot fail anymore. The removal must happen before
1433 * the listq iterator is tainted.
1439 /* Return back to the new pindex to complete vm_page_insert(). */
1440 m->pindex = new_pindex;
1441 m->object = new_object;
1443 vm_page_insert_radixdone(m, new_object, mpred);
1449 * Convert all of the given object's cached pages that have a
1450 * pindex within the given range into free pages. If the value
1451 * zero is given for "end", then the range's upper bound is
1452 * infinity. If the given object is backed by a vnode and it
1453 * transitions from having one or more cached pages to none, the
1454 * vnode's hold count is reduced.
1457 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
1462 mtx_lock(&vm_page_queue_free_mtx);
1463 if (__predict_false(vm_radix_is_empty(&object->cache))) {
1464 mtx_unlock(&vm_page_queue_free_mtx);
1467 while ((m = vm_radix_lookup_ge(&object->cache, start)) != NULL) {
1468 if (end != 0 && m->pindex >= end)
1470 vm_radix_remove(&object->cache, m->pindex);
1471 vm_page_cache_turn_free(m);
1473 empty = vm_radix_is_empty(&object->cache);
1474 mtx_unlock(&vm_page_queue_free_mtx);
1475 if (object->type == OBJT_VNODE && empty)
1476 vdrop(object->handle);
1480 * Returns the cached page that is associated with the given
1481 * object and offset. If, however, none exists, returns NULL.
1483 * The free page queue must be locked.
1485 static inline vm_page_t
1486 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex)
1489 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1490 return (vm_radix_lookup(&object->cache, pindex));
1494 * Remove the given cached page from its containing object's
1495 * collection of cached pages.
1497 * The free page queue must be locked.
1500 vm_page_cache_remove(vm_page_t m)
1503 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1504 KASSERT((m->flags & PG_CACHED) != 0,
1505 ("vm_page_cache_remove: page %p is not cached", m));
1506 vm_radix_remove(&m->object->cache, m->pindex);
1508 vm_cnt.v_cache_count--;
1512 * Transfer all of the cached pages with offset greater than or
1513 * equal to 'offidxstart' from the original object's cache to the
1514 * new object's cache. However, any cached pages with offset
1515 * greater than or equal to the new object's size are kept in the
1516 * original object. Initially, the new object's cache must be
1517 * empty. Offset 'offidxstart' in the original object must
1518 * correspond to offset zero in the new object.
1520 * The new object must be locked.
1523 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart,
1524 vm_object_t new_object)
1529 * Insertion into an object's collection of cached pages
1530 * requires the object to be locked. In contrast, removal does
1533 VM_OBJECT_ASSERT_WLOCKED(new_object);
1534 KASSERT(vm_radix_is_empty(&new_object->cache),
1535 ("vm_page_cache_transfer: object %p has cached pages",
1537 mtx_lock(&vm_page_queue_free_mtx);
1538 while ((m = vm_radix_lookup_ge(&orig_object->cache,
1539 offidxstart)) != NULL) {
1541 * Transfer all of the pages with offset greater than or
1542 * equal to 'offidxstart' from the original object's
1543 * cache to the new object's cache.
1545 if ((m->pindex - offidxstart) >= new_object->size)
1547 vm_radix_remove(&orig_object->cache, m->pindex);
1548 /* Update the page's object and offset. */
1549 m->object = new_object;
1550 m->pindex -= offidxstart;
1551 if (vm_radix_insert(&new_object->cache, m))
1552 vm_page_cache_turn_free(m);
1554 mtx_unlock(&vm_page_queue_free_mtx);
1558 * Returns TRUE if a cached page is associated with the given object and
1559 * offset, and FALSE otherwise.
1561 * The object must be locked.
1564 vm_page_is_cached(vm_object_t object, vm_pindex_t pindex)
1569 * Insertion into an object's collection of cached pages requires the
1570 * object to be locked. Therefore, if the object is locked and the
1571 * object's collection is empty, there is no need to acquire the free
1572 * page queues lock in order to prove that the specified page doesn't
1575 VM_OBJECT_ASSERT_WLOCKED(object);
1576 if (__predict_true(vm_object_cache_is_empty(object)))
1578 mtx_lock(&vm_page_queue_free_mtx);
1579 m = vm_page_cache_lookup(object, pindex);
1580 mtx_unlock(&vm_page_queue_free_mtx);
1587 * Allocate and return a page that is associated with the specified
1588 * object and offset pair. By default, this page is exclusive busied.
1590 * The caller must always specify an allocation class.
1592 * allocation classes:
1593 * VM_ALLOC_NORMAL normal process request
1594 * VM_ALLOC_SYSTEM system *really* needs a page
1595 * VM_ALLOC_INTERRUPT interrupt time request
1597 * optional allocation flags:
1598 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1599 * intends to allocate
1600 * VM_ALLOC_IFCACHED return page only if it is cached
1601 * VM_ALLOC_IFNOTCACHED return NULL, do not reactivate if the page
1603 * VM_ALLOC_NOBUSY do not exclusive busy the page
1604 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1605 * VM_ALLOC_NOOBJ page is not associated with an object and
1606 * should not be exclusive busy
1607 * VM_ALLOC_SBUSY shared busy the allocated page
1608 * VM_ALLOC_WIRED wire the allocated page
1609 * VM_ALLOC_ZERO prefer a zeroed page
1611 * This routine may not sleep.
1614 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1616 struct vnode *vp = NULL;
1617 vm_object_t m_object;
1619 int flags, req_class;
1621 mpred = 0; /* XXX: pacify gcc */
1622 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1623 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1624 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1625 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1626 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
1629 VM_OBJECT_ASSERT_WLOCKED(object);
1631 req_class = req & VM_ALLOC_CLASS_MASK;
1634 * The page daemon is allowed to dig deeper into the free page list.
1636 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1637 req_class = VM_ALLOC_SYSTEM;
1639 if (object != NULL) {
1640 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1641 KASSERT(mpred == NULL || mpred->pindex != pindex,
1642 ("vm_page_alloc: pindex already allocated"));
1646 * The page allocation request can came from consumers which already
1647 * hold the free page queue mutex, like vm_page_insert() in
1650 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE);
1651 if (vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_free_reserved ||
1652 (req_class == VM_ALLOC_SYSTEM &&
1653 vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_interrupt_free_min) ||
1654 (req_class == VM_ALLOC_INTERRUPT &&
1655 vm_cnt.v_free_count + vm_cnt.v_cache_count > 0)) {
1657 * Allocate from the free queue if the number of free pages
1658 * exceeds the minimum for the request class.
1660 if (object != NULL &&
1661 (m = vm_page_cache_lookup(object, pindex)) != NULL) {
1662 if ((req & VM_ALLOC_IFNOTCACHED) != 0) {
1663 mtx_unlock(&vm_page_queue_free_mtx);
1666 if (vm_phys_unfree_page(m))
1667 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0);
1668 #if VM_NRESERVLEVEL > 0
1669 else if (!vm_reserv_reactivate_page(m))
1673 panic("vm_page_alloc: cache page %p is missing"
1674 " from the free queue", m);
1675 } else if ((req & VM_ALLOC_IFCACHED) != 0) {
1676 mtx_unlock(&vm_page_queue_free_mtx);
1678 #if VM_NRESERVLEVEL > 0
1679 } else if (object == NULL || (object->flags & (OBJ_COLORED |
1680 OBJ_FICTITIOUS)) != OBJ_COLORED || (m =
1681 vm_reserv_alloc_page(object, pindex, mpred)) == NULL) {
1685 m = vm_phys_alloc_pages(object != NULL ?
1686 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1687 #if VM_NRESERVLEVEL > 0
1688 if (m == NULL && vm_reserv_reclaim_inactive()) {
1689 m = vm_phys_alloc_pages(object != NULL ?
1690 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1697 * Not allocatable, give up.
1699 mtx_unlock(&vm_page_queue_free_mtx);
1700 atomic_add_int(&vm_pageout_deficit,
1701 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
1702 pagedaemon_wakeup();
1707 * At this point we had better have found a good page.
1709 KASSERT(m != NULL, ("vm_page_alloc: missing page"));
1710 KASSERT(m->queue == PQ_NONE,
1711 ("vm_page_alloc: page %p has unexpected queue %d", m, m->queue));
1712 KASSERT(m->wire_count == 0, ("vm_page_alloc: page %p is wired", m));
1713 KASSERT(m->hold_count == 0, ("vm_page_alloc: page %p is held", m));
1714 KASSERT(!vm_page_busied(m), ("vm_page_alloc: page %p is busy", m));
1715 KASSERT(m->dirty == 0, ("vm_page_alloc: page %p is dirty", m));
1716 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
1717 ("vm_page_alloc: page %p has unexpected memattr %d", m,
1718 pmap_page_get_memattr(m)));
1719 if ((m->flags & PG_CACHED) != 0) {
1720 KASSERT((m->flags & PG_ZERO) == 0,
1721 ("vm_page_alloc: cached page %p is PG_ZERO", m));
1722 KASSERT(m->valid != 0,
1723 ("vm_page_alloc: cached page %p is invalid", m));
1724 if (m->object == object && m->pindex == pindex)
1725 vm_cnt.v_reactivated++;
1728 m_object = m->object;
1729 vm_page_cache_remove(m);
1730 if (m_object->type == OBJT_VNODE &&
1731 vm_object_cache_is_empty(m_object))
1732 vp = m_object->handle;
1734 KASSERT(m->valid == 0,
1735 ("vm_page_alloc: free page %p is valid", m));
1736 vm_phys_freecnt_adj(m, -1);
1738 mtx_unlock(&vm_page_queue_free_mtx);
1741 * Initialize the page. Only the PG_ZERO flag is inherited.
1744 if ((req & VM_ALLOC_ZERO) != 0)
1747 if ((req & VM_ALLOC_NODUMP) != 0)
1751 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1753 m->busy_lock = VPB_UNBUSIED;
1754 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1755 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1756 if ((req & VM_ALLOC_SBUSY) != 0)
1757 m->busy_lock = VPB_SHARERS_WORD(1);
1758 if (req & VM_ALLOC_WIRED) {
1760 * The page lock is not required for wiring a page until that
1761 * page is inserted into the object.
1763 atomic_add_int(&vm_cnt.v_wire_count, 1);
1768 if (object != NULL) {
1769 if (vm_page_insert_after(m, object, pindex, mpred)) {
1770 /* See the comment below about hold count. */
1773 pagedaemon_wakeup();
1774 if (req & VM_ALLOC_WIRED) {
1775 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
1779 m->oflags = VPO_UNMANAGED;
1780 m->busy_lock = VPB_UNBUSIED;
1785 /* Ignore device objects; the pager sets "memattr" for them. */
1786 if (object->memattr != VM_MEMATTR_DEFAULT &&
1787 (object->flags & OBJ_FICTITIOUS) == 0)
1788 pmap_page_set_memattr(m, object->memattr);
1793 * The following call to vdrop() must come after the above call
1794 * to vm_page_insert() in case both affect the same object and
1795 * vnode. Otherwise, the affected vnode's hold count could
1796 * temporarily become zero.
1802 * Don't wakeup too often - wakeup the pageout daemon when
1803 * we would be nearly out of memory.
1805 if (vm_paging_needed())
1806 pagedaemon_wakeup();
1812 vm_page_alloc_contig_vdrop(struct spglist *lst)
1815 while (!SLIST_EMPTY(lst)) {
1816 vdrop((struct vnode *)SLIST_FIRST(lst)-> plinks.s.pv);
1817 SLIST_REMOVE_HEAD(lst, plinks.s.ss);
1822 * vm_page_alloc_contig:
1824 * Allocate a contiguous set of physical pages of the given size "npages"
1825 * from the free lists. All of the physical pages must be at or above
1826 * the given physical address "low" and below the given physical address
1827 * "high". The given value "alignment" determines the alignment of the
1828 * first physical page in the set. If the given value "boundary" is
1829 * non-zero, then the set of physical pages cannot cross any physical
1830 * address boundary that is a multiple of that value. Both "alignment"
1831 * and "boundary" must be a power of two.
1833 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1834 * then the memory attribute setting for the physical pages is configured
1835 * to the object's memory attribute setting. Otherwise, the memory
1836 * attribute setting for the physical pages is configured to "memattr",
1837 * overriding the object's memory attribute setting. However, if the
1838 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1839 * memory attribute setting for the physical pages cannot be configured
1840 * to VM_MEMATTR_DEFAULT.
1842 * The caller must always specify an allocation class.
1844 * allocation classes:
1845 * VM_ALLOC_NORMAL normal process request
1846 * VM_ALLOC_SYSTEM system *really* needs a page
1847 * VM_ALLOC_INTERRUPT interrupt time request
1849 * optional allocation flags:
1850 * VM_ALLOC_NOBUSY do not exclusive busy the page
1851 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1852 * VM_ALLOC_NOOBJ page is not associated with an object and
1853 * should not be exclusive busy
1854 * VM_ALLOC_SBUSY shared busy the allocated page
1855 * VM_ALLOC_WIRED wire the allocated page
1856 * VM_ALLOC_ZERO prefer a zeroed page
1858 * This routine may not sleep.
1861 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1862 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1863 vm_paddr_t boundary, vm_memattr_t memattr)
1866 struct spglist deferred_vdrop_list;
1867 vm_page_t m, m_tmp, m_ret;
1871 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1872 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1873 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1874 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1875 ("vm_page_alloc: inconsistent object(%p)/req(%x)", (void *)object,
1877 if (object != NULL) {
1878 VM_OBJECT_ASSERT_WLOCKED(object);
1879 KASSERT(object->type == OBJT_PHYS,
1880 ("vm_page_alloc_contig: object %p isn't OBJT_PHYS",
1883 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
1884 req_class = req & VM_ALLOC_CLASS_MASK;
1887 * The page daemon is allowed to dig deeper into the free page list.
1889 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1890 req_class = VM_ALLOC_SYSTEM;
1892 SLIST_INIT(&deferred_vdrop_list);
1893 mtx_lock(&vm_page_queue_free_mtx);
1894 if (vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages +
1895 vm_cnt.v_free_reserved || (req_class == VM_ALLOC_SYSTEM &&
1896 vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages +
1897 vm_cnt.v_interrupt_free_min) || (req_class == VM_ALLOC_INTERRUPT &&
1898 vm_cnt.v_free_count + vm_cnt.v_cache_count >= npages)) {
1899 #if VM_NRESERVLEVEL > 0
1901 if (object == NULL || (object->flags & OBJ_COLORED) == 0 ||
1902 (m_ret = vm_reserv_alloc_contig(object, pindex, npages,
1903 low, high, alignment, boundary)) == NULL)
1905 m_ret = vm_phys_alloc_contig(npages, low, high,
1906 alignment, boundary);
1908 mtx_unlock(&vm_page_queue_free_mtx);
1909 atomic_add_int(&vm_pageout_deficit, npages);
1910 pagedaemon_wakeup();
1914 for (m = m_ret; m < &m_ret[npages]; m++) {
1915 drop = vm_page_alloc_init(m);
1918 * Enqueue the vnode for deferred vdrop().
1920 m->plinks.s.pv = drop;
1921 SLIST_INSERT_HEAD(&deferred_vdrop_list, m,
1926 #if VM_NRESERVLEVEL > 0
1927 if (vm_reserv_reclaim_contig(npages, low, high, alignment,
1932 mtx_unlock(&vm_page_queue_free_mtx);
1937 * Initialize the pages. Only the PG_ZERO flag is inherited.
1940 if ((req & VM_ALLOC_ZERO) != 0)
1942 if ((req & VM_ALLOC_NODUMP) != 0)
1944 if ((req & VM_ALLOC_WIRED) != 0)
1945 atomic_add_int(&vm_cnt.v_wire_count, npages);
1946 if (object != NULL) {
1947 if (object->memattr != VM_MEMATTR_DEFAULT &&
1948 memattr == VM_MEMATTR_DEFAULT)
1949 memattr = object->memattr;
1951 for (m = m_ret; m < &m_ret[npages]; m++) {
1953 m->flags = (m->flags | PG_NODUMP) & flags;
1954 m->busy_lock = VPB_UNBUSIED;
1955 if (object != NULL) {
1956 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
1957 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1958 if ((req & VM_ALLOC_SBUSY) != 0)
1959 m->busy_lock = VPB_SHARERS_WORD(1);
1961 if ((req & VM_ALLOC_WIRED) != 0)
1963 /* Unmanaged pages don't use "act_count". */
1964 m->oflags = VPO_UNMANAGED;
1965 if (object != NULL) {
1966 if (vm_page_insert(m, object, pindex)) {
1967 vm_page_alloc_contig_vdrop(
1968 &deferred_vdrop_list);
1969 if (vm_paging_needed())
1970 pagedaemon_wakeup();
1971 if ((req & VM_ALLOC_WIRED) != 0)
1972 atomic_subtract_int(&vm_cnt.v_wire_count,
1974 for (m_tmp = m, m = m_ret;
1975 m < &m_ret[npages]; m++) {
1976 if ((req & VM_ALLOC_WIRED) != 0)
1980 m->oflags |= VPO_UNMANAGED;
1982 m->busy_lock = VPB_UNBUSIED;
1989 if (memattr != VM_MEMATTR_DEFAULT)
1990 pmap_page_set_memattr(m, memattr);
1993 vm_page_alloc_contig_vdrop(&deferred_vdrop_list);
1994 if (vm_paging_needed())
1995 pagedaemon_wakeup();
2000 * Initialize a page that has been freshly dequeued from a freelist.
2001 * The caller has to drop the vnode returned, if it is not NULL.
2003 * This function may only be used to initialize unmanaged pages.
2005 * To be called with vm_page_queue_free_mtx held.
2007 static struct vnode *
2008 vm_page_alloc_init(vm_page_t m)
2011 vm_object_t m_object;
2013 KASSERT(m->queue == PQ_NONE,
2014 ("vm_page_alloc_init: page %p has unexpected queue %d",
2016 KASSERT(m->wire_count == 0,
2017 ("vm_page_alloc_init: page %p is wired", m));
2018 KASSERT(m->hold_count == 0,
2019 ("vm_page_alloc_init: page %p is held", m));
2020 KASSERT(!vm_page_busied(m),
2021 ("vm_page_alloc_init: page %p is busy", m));
2022 KASSERT(m->dirty == 0,
2023 ("vm_page_alloc_init: page %p is dirty", m));
2024 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2025 ("vm_page_alloc_init: page %p has unexpected memattr %d",
2026 m, pmap_page_get_memattr(m)));
2027 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2029 if ((m->flags & PG_CACHED) != 0) {
2030 KASSERT((m->flags & PG_ZERO) == 0,
2031 ("vm_page_alloc_init: cached page %p is PG_ZERO", m));
2033 m_object = m->object;
2034 vm_page_cache_remove(m);
2035 if (m_object->type == OBJT_VNODE &&
2036 vm_object_cache_is_empty(m_object))
2037 drop = m_object->handle;
2039 KASSERT(m->valid == 0,
2040 ("vm_page_alloc_init: free page %p is valid", m));
2041 vm_phys_freecnt_adj(m, -1);
2047 * vm_page_alloc_freelist:
2049 * Allocate a physical page from the specified free page list.
2051 * The caller must always specify an allocation class.
2053 * allocation classes:
2054 * VM_ALLOC_NORMAL normal process request
2055 * VM_ALLOC_SYSTEM system *really* needs a page
2056 * VM_ALLOC_INTERRUPT interrupt time request
2058 * optional allocation flags:
2059 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
2060 * intends to allocate
2061 * VM_ALLOC_WIRED wire the allocated page
2062 * VM_ALLOC_ZERO prefer a zeroed page
2064 * This routine may not sleep.
2067 vm_page_alloc_freelist(int flind, int req)
2074 req_class = req & VM_ALLOC_CLASS_MASK;
2077 * The page daemon is allowed to dig deeper into the free page list.
2079 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2080 req_class = VM_ALLOC_SYSTEM;
2083 * Do not allocate reserved pages unless the req has asked for it.
2085 mtx_lock_flags(&vm_page_queue_free_mtx, MTX_RECURSE);
2086 if (vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_free_reserved ||
2087 (req_class == VM_ALLOC_SYSTEM &&
2088 vm_cnt.v_free_count + vm_cnt.v_cache_count > vm_cnt.v_interrupt_free_min) ||
2089 (req_class == VM_ALLOC_INTERRUPT &&
2090 vm_cnt.v_free_count + vm_cnt.v_cache_count > 0))
2091 m = vm_phys_alloc_freelist_pages(flind, VM_FREEPOOL_DIRECT, 0);
2093 mtx_unlock(&vm_page_queue_free_mtx);
2094 atomic_add_int(&vm_pageout_deficit,
2095 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
2096 pagedaemon_wakeup();
2100 mtx_unlock(&vm_page_queue_free_mtx);
2103 drop = vm_page_alloc_init(m);
2104 mtx_unlock(&vm_page_queue_free_mtx);
2107 * Initialize the page. Only the PG_ZERO flag is inherited.
2111 if ((req & VM_ALLOC_ZERO) != 0)
2114 if ((req & VM_ALLOC_WIRED) != 0) {
2116 * The page lock is not required for wiring a page that does
2117 * not belong to an object.
2119 atomic_add_int(&vm_cnt.v_wire_count, 1);
2122 /* Unmanaged pages don't use "act_count". */
2123 m->oflags = VPO_UNMANAGED;
2126 if (vm_paging_needed())
2127 pagedaemon_wakeup();
2131 #define VPSC_ANY 0 /* No restrictions. */
2132 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
2133 #define VPSC_NOSUPER 2 /* Skip superpages. */
2136 * vm_page_scan_contig:
2138 * Scan vm_page_array[] between the specified entries "m_start" and
2139 * "m_end" for a run of contiguous physical pages that satisfy the
2140 * specified conditions, and return the lowest page in the run. The
2141 * specified "alignment" determines the alignment of the lowest physical
2142 * page in the run. If the specified "boundary" is non-zero, then the
2143 * run of physical pages cannot span a physical address that is a
2144 * multiple of "boundary".
2146 * "m_end" is never dereferenced, so it need not point to a vm_page
2147 * structure within vm_page_array[].
2149 * "npages" must be greater than zero. "m_start" and "m_end" must not
2150 * span a hole (or discontiguity) in the physical address space. Both
2151 * "alignment" and "boundary" must be a power of two.
2154 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2155 u_long alignment, vm_paddr_t boundary, int options)
2157 struct mtx *m_mtx, *new_mtx;
2161 #if VM_NRESERVLEVEL > 0
2164 int m_inc, order, run_ext, run_len;
2166 KASSERT(npages > 0, ("npages is 0"));
2167 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2168 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2172 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2173 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2174 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2177 * If the current page would be the start of a run, check its
2178 * physical address against the end, alignment, and boundary
2179 * conditions. If it doesn't satisfy these conditions, either
2180 * terminate the scan or advance to the next page that
2181 * satisfies the failed condition.
2184 KASSERT(m_run == NULL, ("m_run != NULL"));
2185 if (m + npages > m_end)
2187 pa = VM_PAGE_TO_PHYS(m);
2188 if ((pa & (alignment - 1)) != 0) {
2189 m_inc = atop(roundup2(pa, alignment) - pa);
2192 if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
2194 m_inc = atop(roundup2(pa, boundary) - pa);
2198 KASSERT(m_run != NULL, ("m_run == NULL"));
2201 * Avoid releasing and reacquiring the same page lock.
2203 new_mtx = vm_page_lockptr(m);
2204 if (m_mtx != new_mtx) {
2212 if (m->wire_count != 0 || m->hold_count != 0)
2214 #if VM_NRESERVLEVEL > 0
2215 else if ((level = vm_reserv_level(m)) >= 0 &&
2216 (options & VPSC_NORESERV) != 0) {
2218 /* Advance to the end of the reservation. */
2219 pa = VM_PAGE_TO_PHYS(m);
2220 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2224 else if ((object = m->object) != NULL) {
2226 * The page is considered eligible for relocation if
2227 * and only if it could be laundered or reclaimed by
2230 if (!VM_OBJECT_TRYRLOCK(object)) {
2232 VM_OBJECT_RLOCK(object);
2234 if (m->object != object) {
2236 * The page may have been freed.
2238 VM_OBJECT_RUNLOCK(object);
2240 } else if (m->wire_count != 0 ||
2241 m->hold_count != 0) {
2246 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2247 ("page %p is PG_UNHOLDFREE", m));
2248 /* Don't care: PG_NODUMP, PG_WINATCFLS, PG_ZERO. */
2249 if (object->type != OBJT_DEFAULT &&
2250 object->type != OBJT_SWAP &&
2251 object->type != OBJT_VNODE)
2253 else if ((m->flags & PG_CACHED) != 0 ||
2254 m != vm_page_lookup(object, m->pindex)) {
2256 * The page is cached or recently converted
2257 * from cached to free.
2259 #if VM_NRESERVLEVEL > 0
2262 * The page is reserved. Extend the
2263 * current run by one page.
2268 if ((order = m->order) < VM_NFREEORDER) {
2270 * The page is enqueued in the
2271 * physical memory allocator's cache/
2272 * free page queues. Moreover, it is
2273 * the first page in a power-of-two-
2274 * sized run of contiguous cache/free
2275 * pages. Add these pages to the end
2276 * of the current run, and jump
2279 run_ext = 1 << order;
2283 #if VM_NRESERVLEVEL > 0
2284 } else if ((options & VPSC_NOSUPER) != 0 &&
2285 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2287 /* Advance to the end of the superpage. */
2288 pa = VM_PAGE_TO_PHYS(m);
2289 m_inc = atop(roundup2(pa + 1,
2290 vm_reserv_size(level)) - pa);
2292 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2293 m->queue != PQ_NONE && !vm_page_busied(m)) {
2295 * The page is allocated but eligible for
2296 * relocation. Extend the current run by one
2299 KASSERT(pmap_page_get_memattr(m) ==
2301 ("page %p has an unexpected memattr", m));
2302 KASSERT((m->oflags & (VPO_SWAPINPROG |
2303 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2304 ("page %p has unexpected oflags", m));
2305 /* Don't care: VPO_NOSYNC. */
2310 VM_OBJECT_RUNLOCK(object);
2311 #if VM_NRESERVLEVEL > 0
2312 } else if (level >= 0) {
2314 * The page is reserved but not yet allocated. In
2315 * other words, it is still cached or free. Extend
2316 * the current run by one page.
2320 } else if ((order = m->order) < VM_NFREEORDER) {
2322 * The page is enqueued in the physical memory
2323 * allocator's cache/free page queues. Moreover, it
2324 * is the first page in a power-of-two-sized run of
2325 * contiguous cache/free pages. Add these pages to
2326 * the end of the current run, and jump ahead.
2328 run_ext = 1 << order;
2332 * Skip the page for one of the following reasons: (1)
2333 * It is enqueued in the physical memory allocator's
2334 * cache/free page queues. However, it is not the
2335 * first page in a run of contiguous cache/free pages.
2336 * (This case rarely occurs because the scan is
2337 * performed in ascending order.) (2) It is not
2338 * reserved, and it is transitioning from free to
2339 * allocated. (Conversely, the transition from
2340 * allocated to free for managed pages is blocked by
2341 * the page lock.) (3) It is allocated but not
2342 * contained by an object and not wired, e.g.,
2343 * allocated by Xen's balloon driver.
2349 * Extend or reset the current run of pages.
2364 if (run_len >= npages)
2370 * vm_page_reclaim_run:
2372 * Try to relocate each of the allocated virtual pages within the
2373 * specified run of physical pages to a new physical address. Free the
2374 * physical pages underlying the relocated virtual pages. A virtual page
2375 * is relocatable if and only if it could be laundered or reclaimed by
2376 * the page daemon. Whenever possible, a virtual page is relocated to a
2377 * physical address above "high".
2379 * Returns 0 if every physical page within the run was already free or
2380 * just freed by a successful relocation. Otherwise, returns a non-zero
2381 * value indicating why the last attempt to relocate a virtual page was
2384 * "req_class" must be an allocation class.
2387 vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
2390 struct mtx *m_mtx, *new_mtx;
2391 struct spglist free;
2394 vm_page_t m, m_end, m_new;
2395 int error, order, req;
2397 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2398 ("req_class is not an allocation class"));
2402 m_end = m_run + npages;
2404 for (; error == 0 && m < m_end; m++) {
2405 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2406 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2409 * Avoid releasing and reacquiring the same page lock.
2411 new_mtx = vm_page_lockptr(m);
2412 if (m_mtx != new_mtx) {
2419 if (m->wire_count != 0 || m->hold_count != 0)
2421 else if ((object = m->object) != NULL) {
2423 * The page is relocated if and only if it could be
2424 * laundered or reclaimed by the page daemon.
2426 if (!VM_OBJECT_TRYWLOCK(object)) {
2428 VM_OBJECT_WLOCK(object);
2430 if (m->object != object) {
2432 * The page may have been freed.
2434 VM_OBJECT_WUNLOCK(object);
2436 } else if (m->wire_count != 0 ||
2437 m->hold_count != 0) {
2442 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2443 ("page %p is PG_UNHOLDFREE", m));
2444 /* Don't care: PG_NODUMP, PG_WINATCFLS, PG_ZERO. */
2445 if (object->type != OBJT_DEFAULT &&
2446 object->type != OBJT_SWAP &&
2447 object->type != OBJT_VNODE)
2449 else if ((m->flags & PG_CACHED) != 0 ||
2450 m != vm_page_lookup(object, m->pindex)) {
2452 * The page is cached or recently converted
2453 * from cached to free.
2455 VM_OBJECT_WUNLOCK(object);
2457 } else if (object->memattr != VM_MEMATTR_DEFAULT)
2459 else if (m->queue != PQ_NONE && !vm_page_busied(m)) {
2460 KASSERT(pmap_page_get_memattr(m) ==
2462 ("page %p has an unexpected memattr", m));
2463 KASSERT((m->oflags & (VPO_SWAPINPROG |
2464 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2465 ("page %p has unexpected oflags", m));
2466 /* Don't care: VPO_NOSYNC. */
2467 if (m->valid != 0) {
2469 * First, try to allocate a new page
2470 * that is above "high". Failing
2471 * that, try to allocate a new page
2472 * that is below "m_run". Allocate
2473 * the new page between the end of
2474 * "m_run" and "high" only as a last
2477 req = req_class | VM_ALLOC_NOOBJ;
2478 if ((m->flags & PG_NODUMP) != 0)
2479 req |= VM_ALLOC_NODUMP;
2480 if (trunc_page(high) !=
2481 ~(vm_paddr_t)PAGE_MASK) {
2482 m_new = vm_page_alloc_contig(
2487 VM_MEMATTR_DEFAULT);
2490 if (m_new == NULL) {
2491 pa = VM_PAGE_TO_PHYS(m_run);
2492 m_new = vm_page_alloc_contig(
2494 0, pa - 1, PAGE_SIZE, 0,
2495 VM_MEMATTR_DEFAULT);
2497 if (m_new == NULL) {
2499 m_new = vm_page_alloc_contig(
2501 pa, high, PAGE_SIZE, 0,
2502 VM_MEMATTR_DEFAULT);
2504 if (m_new == NULL) {
2508 KASSERT(m_new->wire_count == 0,
2509 ("page %p is wired", m));
2512 * Replace "m" with the new page. For
2513 * vm_page_replace(), "m" must be busy
2514 * and dequeued. Finally, change "m"
2515 * as if vm_page_free() was called.
2517 if (object->ref_count != 0)
2519 m_new->aflags = m->aflags;
2520 KASSERT(m_new->oflags == VPO_UNMANAGED,
2521 ("page %p is managed", m));
2522 m_new->oflags = m->oflags & VPO_NOSYNC;
2523 pmap_copy_page(m, m_new);
2524 m_new->valid = m->valid;
2525 m_new->dirty = m->dirty;
2526 m->flags &= ~PG_ZERO;
2529 vm_page_replace_checked(m_new, object,
2535 * The new page must be deactivated
2536 * before the object is unlocked.
2538 new_mtx = vm_page_lockptr(m_new);
2539 if (m_mtx != new_mtx) {
2544 vm_page_deactivate(m_new);
2546 m->flags &= ~PG_ZERO;
2549 KASSERT(m->dirty == 0,
2550 ("page %p is dirty", m));
2552 SLIST_INSERT_HEAD(&free, m, plinks.s.ss);
2556 VM_OBJECT_WUNLOCK(object);
2559 mtx_lock(&vm_page_queue_free_mtx);
2561 if (order < VM_NFREEORDER) {
2563 * The page is enqueued in the physical memory
2564 * allocator's cache/free page queues.
2565 * Moreover, it is the first page in a power-
2566 * of-two-sized run of contiguous cache/free
2567 * pages. Jump ahead to the last page within
2568 * that run, and continue from there.
2570 m += (1 << order) - 1;
2572 #if VM_NRESERVLEVEL > 0
2573 else if (vm_reserv_is_page_free(m))
2576 mtx_unlock(&vm_page_queue_free_mtx);
2577 if (order == VM_NFREEORDER)
2583 if ((m = SLIST_FIRST(&free)) != NULL) {
2584 mtx_lock(&vm_page_queue_free_mtx);
2586 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
2587 vm_phys_freecnt_adj(m, 1);
2588 #if VM_NRESERVLEVEL > 0
2589 if (!vm_reserv_free_page(m))
2593 vm_phys_free_pages(m, 0);
2594 } while ((m = SLIST_FIRST(&free)) != NULL);
2595 vm_page_free_wakeup();
2596 mtx_unlock(&vm_page_queue_free_mtx);
2603 CTASSERT(powerof2(NRUNS));
2605 #define RUN_INDEX(count) ((count) & (NRUNS - 1))
2607 #define MIN_RECLAIM 8
2610 * vm_page_reclaim_contig:
2612 * Reclaim allocated, contiguous physical memory satisfying the specified
2613 * conditions by relocating the virtual pages using that physical memory.
2614 * Returns true if reclamation is successful and false otherwise. Since
2615 * relocation requires the allocation of physical pages, reclamation may
2616 * fail due to a shortage of cache/free pages. When reclamation fails,
2617 * callers are expected to perform VM_WAIT before retrying a failed
2618 * allocation operation, e.g., vm_page_alloc_contig().
2620 * The caller must always specify an allocation class through "req".
2622 * allocation classes:
2623 * VM_ALLOC_NORMAL normal process request
2624 * VM_ALLOC_SYSTEM system *really* needs a page
2625 * VM_ALLOC_INTERRUPT interrupt time request
2627 * The optional allocation flags are ignored.
2629 * "npages" must be greater than zero. Both "alignment" and "boundary"
2630 * must be a power of two.
2633 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
2634 u_long alignment, vm_paddr_t boundary)
2636 vm_paddr_t curr_low;
2637 vm_page_t m_run, m_runs[NRUNS];
2638 u_long count, reclaimed;
2639 int error, i, options, req_class;
2641 KASSERT(npages > 0, ("npages is 0"));
2642 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2643 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2644 req_class = req & VM_ALLOC_CLASS_MASK;
2647 * The page daemon is allowed to dig deeper into the free page list.
2649 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2650 req_class = VM_ALLOC_SYSTEM;
2653 * Return if the number of cached and free pages cannot satisfy the
2654 * requested allocation.
2656 count = vm_cnt.v_free_count + vm_cnt.v_cache_count;
2657 if (count < npages + vm_cnt.v_free_reserved || (count < npages +
2658 vm_cnt.v_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
2659 (count < npages && req_class == VM_ALLOC_INTERRUPT))
2663 * Scan up to three times, relaxing the restrictions ("options") on
2664 * the reclamation of reservations and superpages each time.
2666 for (options = VPSC_NORESERV;;) {
2668 * Find the highest runs that satisfy the given constraints
2669 * and restrictions, and record them in "m_runs".
2674 m_run = vm_phys_scan_contig(npages, curr_low, high,
2675 alignment, boundary, options);
2678 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages);
2679 m_runs[RUN_INDEX(count)] = m_run;
2684 * Reclaim the highest runs in LIFO (descending) order until
2685 * the number of reclaimed pages, "reclaimed", is at least
2686 * MIN_RECLAIM. Reset "reclaimed" each time because each
2687 * reclamation is idempotent, and runs will (likely) recur
2688 * from one scan to the next as restrictions are relaxed.
2691 for (i = 0; count > 0 && i < NRUNS; i++) {
2693 m_run = m_runs[RUN_INDEX(count)];
2694 error = vm_page_reclaim_run(req_class, npages, m_run,
2697 reclaimed += npages;
2698 if (reclaimed >= MIN_RECLAIM)
2704 * Either relax the restrictions on the next scan or return if
2705 * the last scan had no restrictions.
2707 if (options == VPSC_NORESERV)
2708 options = VPSC_NOSUPER;
2709 else if (options == VPSC_NOSUPER)
2711 else if (options == VPSC_ANY)
2712 return (reclaimed != 0);
2717 * vm_wait: (also see VM_WAIT macro)
2719 * Sleep until free pages are available for allocation.
2720 * - Called in various places before memory allocations.
2726 mtx_lock(&vm_page_queue_free_mtx);
2727 if (curproc == pageproc) {
2728 vm_pageout_pages_needed = 1;
2729 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx,
2730 PDROP | PSWP, "VMWait", 0);
2732 if (!vm_pageout_wanted) {
2733 vm_pageout_wanted = true;
2734 wakeup(&vm_pageout_wanted);
2736 vm_pages_needed = true;
2737 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM,
2743 * vm_waitpfault: (also see VM_WAITPFAULT macro)
2745 * Sleep until free pages are available for allocation.
2746 * - Called only in vm_fault so that processes page faulting
2747 * can be easily tracked.
2748 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
2749 * processes will be able to grab memory first. Do not change
2750 * this balance without careful testing first.
2756 mtx_lock(&vm_page_queue_free_mtx);
2757 if (!vm_pageout_wanted) {
2758 vm_pageout_wanted = true;
2759 wakeup(&vm_pageout_wanted);
2761 vm_pages_needed = true;
2762 msleep(&vm_cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
2766 struct vm_pagequeue *
2767 vm_page_pagequeue(vm_page_t m)
2770 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]);
2776 * Remove the given page from its current page queue.
2778 * The page must be locked.
2781 vm_page_dequeue(vm_page_t m)
2783 struct vm_pagequeue *pq;
2785 vm_page_assert_locked(m);
2786 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued",
2788 pq = vm_page_pagequeue(m);
2789 vm_pagequeue_lock(pq);
2791 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2792 vm_pagequeue_cnt_dec(pq);
2793 vm_pagequeue_unlock(pq);
2797 * vm_page_dequeue_locked:
2799 * Remove the given page from its current page queue.
2801 * The page and page queue must be locked.
2804 vm_page_dequeue_locked(vm_page_t m)
2806 struct vm_pagequeue *pq;
2808 vm_page_lock_assert(m, MA_OWNED);
2809 pq = vm_page_pagequeue(m);
2810 vm_pagequeue_assert_locked(pq);
2812 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2813 vm_pagequeue_cnt_dec(pq);
2819 * Add the given page to the specified page queue.
2821 * The page must be locked.
2824 vm_page_enqueue(uint8_t queue, vm_page_t m)
2826 struct vm_pagequeue *pq;
2828 vm_page_lock_assert(m, MA_OWNED);
2829 KASSERT(queue < PQ_COUNT,
2830 ("vm_page_enqueue: invalid queue %u request for page %p",
2832 pq = &vm_phys_domain(m)->vmd_pagequeues[queue];
2833 vm_pagequeue_lock(pq);
2835 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2836 vm_pagequeue_cnt_inc(pq);
2837 vm_pagequeue_unlock(pq);
2843 * Move the given page to the tail of its current page queue.
2845 * The page must be locked.
2848 vm_page_requeue(vm_page_t m)
2850 struct vm_pagequeue *pq;
2852 vm_page_lock_assert(m, MA_OWNED);
2853 KASSERT(m->queue != PQ_NONE,
2854 ("vm_page_requeue: page %p is not queued", m));
2855 pq = vm_page_pagequeue(m);
2856 vm_pagequeue_lock(pq);
2857 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2858 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2859 vm_pagequeue_unlock(pq);
2863 * vm_page_requeue_locked:
2865 * Move the given page to the tail of its current page queue.
2867 * The page queue must be locked.
2870 vm_page_requeue_locked(vm_page_t m)
2872 struct vm_pagequeue *pq;
2874 KASSERT(m->queue != PQ_NONE,
2875 ("vm_page_requeue_locked: page %p is not queued", m));
2876 pq = vm_page_pagequeue(m);
2877 vm_pagequeue_assert_locked(pq);
2878 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2879 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2885 * Put the specified page on the active list (if appropriate).
2886 * Ensure that act_count is at least ACT_INIT but do not otherwise
2889 * The page must be locked.
2892 vm_page_activate(vm_page_t m)
2896 vm_page_lock_assert(m, MA_OWNED);
2897 if ((queue = m->queue) != PQ_ACTIVE) {
2898 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2899 if (m->act_count < ACT_INIT)
2900 m->act_count = ACT_INIT;
2901 if (queue != PQ_NONE)
2903 vm_page_enqueue(PQ_ACTIVE, m);
2905 KASSERT(queue == PQ_NONE,
2906 ("vm_page_activate: wired page %p is queued", m));
2908 if (m->act_count < ACT_INIT)
2909 m->act_count = ACT_INIT;
2914 * vm_page_free_wakeup:
2916 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
2917 * routine is called when a page has been added to the cache or free
2920 * The page queues must be locked.
2923 vm_page_free_wakeup(void)
2926 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2928 * if pageout daemon needs pages, then tell it that there are
2931 if (vm_pageout_pages_needed &&
2932 vm_cnt.v_cache_count + vm_cnt.v_free_count >= vm_cnt.v_pageout_free_min) {
2933 wakeup(&vm_pageout_pages_needed);
2934 vm_pageout_pages_needed = 0;
2937 * wakeup processes that are waiting on memory if we hit a
2938 * high water mark. And wakeup scheduler process if we have
2939 * lots of memory. this process will swapin processes.
2941 if (vm_pages_needed && !vm_page_count_min()) {
2942 vm_pages_needed = false;
2943 wakeup(&vm_cnt.v_free_count);
2948 * Turn a cached page into a free page, by changing its attributes.
2949 * Keep the statistics up-to-date.
2951 * The free page queue must be locked.
2954 vm_page_cache_turn_free(vm_page_t m)
2957 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2961 KASSERT((m->flags & PG_CACHED) != 0,
2962 ("vm_page_cache_turn_free: page %p is not cached", m));
2963 m->flags &= ~PG_CACHED;
2964 vm_cnt.v_cache_count--;
2965 vm_phys_freecnt_adj(m, 1);
2971 * Returns the given page to the free list,
2972 * disassociating it with any VM object.
2974 * The object must be locked. The page must be locked if it is managed.
2977 vm_page_free_toq(vm_page_t m)
2980 if ((m->oflags & VPO_UNMANAGED) == 0) {
2981 vm_page_lock_assert(m, MA_OWNED);
2982 KASSERT(!pmap_page_is_mapped(m),
2983 ("vm_page_free_toq: freeing mapped page %p", m));
2985 KASSERT(m->queue == PQ_NONE,
2986 ("vm_page_free_toq: unmanaged page %p is queued", m));
2987 PCPU_INC(cnt.v_tfree);
2989 if (vm_page_sbusied(m))
2990 panic("vm_page_free: freeing busy page %p", m);
2993 * Unqueue, then remove page. Note that we cannot destroy
2994 * the page here because we do not want to call the pager's
2995 * callback routine until after we've put the page on the
2996 * appropriate free queue.
3002 * If fictitious remove object association and
3003 * return, otherwise delay object association removal.
3005 if ((m->flags & PG_FICTITIOUS) != 0) {
3012 if (m->wire_count != 0)
3013 panic("vm_page_free: freeing wired page %p", m);
3014 if (m->hold_count != 0) {
3015 m->flags &= ~PG_ZERO;
3016 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
3017 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m));
3018 m->flags |= PG_UNHOLDFREE;
3021 * Restore the default memory attribute to the page.
3023 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
3024 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
3027 * Insert the page into the physical memory allocator's
3028 * cache/free page queues.
3030 mtx_lock(&vm_page_queue_free_mtx);
3031 vm_phys_freecnt_adj(m, 1);
3032 #if VM_NRESERVLEVEL > 0
3033 if (!vm_reserv_free_page(m))
3037 vm_phys_free_pages(m, 0);
3038 vm_page_free_wakeup();
3039 mtx_unlock(&vm_page_queue_free_mtx);
3046 * Mark this page as wired down by yet
3047 * another map, removing it from paging queues
3050 * If the page is fictitious, then its wire count must remain one.
3052 * The page must be locked.
3055 vm_page_wire(vm_page_t m)
3059 * Only bump the wire statistics if the page is not already wired,
3060 * and only unqueue the page if it is on some queue (if it is unmanaged
3061 * it is already off the queues).
3063 vm_page_lock_assert(m, MA_OWNED);
3064 if ((m->flags & PG_FICTITIOUS) != 0) {
3065 KASSERT(m->wire_count == 1,
3066 ("vm_page_wire: fictitious page %p's wire count isn't one",
3070 if (m->wire_count == 0) {
3071 KASSERT((m->oflags & VPO_UNMANAGED) == 0 ||
3072 m->queue == PQ_NONE,
3073 ("vm_page_wire: unmanaged page %p is queued", m));
3075 atomic_add_int(&vm_cnt.v_wire_count, 1);
3078 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
3084 * Release one wiring of the specified page, potentially allowing it to be
3085 * paged out. Returns TRUE if the number of wirings transitions to zero and
3088 * Only managed pages belonging to an object can be paged out. If the number
3089 * of wirings transitions to zero and the page is eligible for page out, then
3090 * the page is added to the specified paging queue (unless PQ_NONE is
3093 * If a page is fictitious, then its wire count must always be one.
3095 * A managed page must be locked.
3098 vm_page_unwire(vm_page_t m, uint8_t queue)
3101 KASSERT(queue < PQ_COUNT || queue == PQ_NONE,
3102 ("vm_page_unwire: invalid queue %u request for page %p",
3104 if ((m->oflags & VPO_UNMANAGED) == 0)
3105 vm_page_assert_locked(m);
3106 if ((m->flags & PG_FICTITIOUS) != 0) {
3107 KASSERT(m->wire_count == 1,
3108 ("vm_page_unwire: fictitious page %p's wire count isn't one", m));
3111 if (m->wire_count > 0) {
3113 if (m->wire_count == 0) {
3114 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
3115 if ((m->oflags & VPO_UNMANAGED) == 0 &&
3116 m->object != NULL && queue != PQ_NONE) {
3117 if (queue == PQ_INACTIVE)
3118 m->flags &= ~PG_WINATCFLS;
3119 vm_page_enqueue(queue, m);
3125 panic("vm_page_unwire: page %p's wire count is zero", m);
3129 * Move the specified page to the inactive queue.
3131 * Many pages placed on the inactive queue should actually go
3132 * into the cache, but it is difficult to figure out which. What
3133 * we do instead, if the inactive target is well met, is to put
3134 * clean pages at the head of the inactive queue instead of the tail.
3135 * This will cause them to be moved to the cache more quickly and
3136 * if not actively re-referenced, reclaimed more quickly. If we just
3137 * stick these pages at the end of the inactive queue, heavy filesystem
3138 * meta-data accesses can cause an unnecessary paging load on memory bound
3139 * processes. This optimization causes one-time-use metadata to be
3140 * reused more quickly.
3142 * Normally noreuse is FALSE, resulting in LRU operation. noreuse is set
3143 * to TRUE if we want this page to be 'as if it were placed in the cache',
3144 * except without unmapping it from the process address space. In
3145 * practice this is implemented by inserting the page at the head of the
3146 * queue, using a marker page to guide FIFO insertion ordering.
3148 * The page must be locked.
3151 _vm_page_deactivate(vm_page_t m, boolean_t noreuse)
3153 struct vm_pagequeue *pq;
3156 vm_page_assert_locked(m);
3159 * Ignore if the page is already inactive, unless it is unlikely to be
3162 if ((queue = m->queue) == PQ_INACTIVE && !noreuse)
3164 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3165 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE];
3166 /* Avoid multiple acquisitions of the inactive queue lock. */
3167 if (queue == PQ_INACTIVE) {
3168 vm_pagequeue_lock(pq);
3169 vm_page_dequeue_locked(m);
3171 if (queue != PQ_NONE)
3173 m->flags &= ~PG_WINATCFLS;
3174 vm_pagequeue_lock(pq);
3176 m->queue = PQ_INACTIVE;
3178 TAILQ_INSERT_BEFORE(&vm_phys_domain(m)->vmd_inacthead,
3181 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3182 vm_pagequeue_cnt_inc(pq);
3183 vm_pagequeue_unlock(pq);
3188 * Move the specified page to the inactive queue.
3190 * The page must be locked.
3193 vm_page_deactivate(vm_page_t m)
3196 _vm_page_deactivate(m, FALSE);
3200 * Move the specified page to the inactive queue with the expectation
3201 * that it is unlikely to be reused.
3203 * The page must be locked.
3206 vm_page_deactivate_noreuse(vm_page_t m)
3209 _vm_page_deactivate(m, TRUE);
3213 * vm_page_try_to_cache:
3215 * Returns 0 on failure, 1 on success
3218 vm_page_try_to_cache(vm_page_t m)
3221 vm_page_lock_assert(m, MA_OWNED);
3222 VM_OBJECT_ASSERT_WLOCKED(m->object);
3223 if (m->dirty || m->hold_count || m->wire_count ||
3224 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m))
3234 * vm_page_try_to_free()
3236 * Attempt to free the page. If we cannot free it, we do nothing.
3237 * 1 is returned on success, 0 on failure.
3240 vm_page_try_to_free(vm_page_t m)
3243 vm_page_lock_assert(m, MA_OWNED);
3244 if (m->object != NULL)
3245 VM_OBJECT_ASSERT_WLOCKED(m->object);
3246 if (m->dirty || m->hold_count || m->wire_count ||
3247 (m->oflags & VPO_UNMANAGED) != 0 || vm_page_busied(m))
3259 * Put the specified page onto the page cache queue (if appropriate).
3261 * The object and page must be locked.
3264 vm_page_cache(vm_page_t m)
3267 boolean_t cache_was_empty;
3269 vm_page_lock_assert(m, MA_OWNED);
3271 VM_OBJECT_ASSERT_WLOCKED(object);
3272 if (vm_page_busied(m) || (m->oflags & VPO_UNMANAGED) ||
3273 m->hold_count || m->wire_count)
3274 panic("vm_page_cache: attempting to cache busy page");
3275 KASSERT(!pmap_page_is_mapped(m),
3276 ("vm_page_cache: page %p is mapped", m));
3277 KASSERT(m->dirty == 0, ("vm_page_cache: page %p is dirty", m));
3278 if (m->valid == 0 || object->type == OBJT_DEFAULT ||
3279 (object->type == OBJT_SWAP &&
3280 !vm_pager_has_page(object, m->pindex, NULL, NULL))) {
3282 * Hypothesis: A cache-eligible page belonging to a
3283 * default object or swap object but without a backing
3284 * store must be zero filled.
3289 KASSERT((m->flags & PG_CACHED) == 0,
3290 ("vm_page_cache: page %p is already cached", m));
3293 * Remove the page from the paging queues.
3298 * Remove the page from the object's collection of resident
3301 vm_radix_remove(&object->rtree, m->pindex);
3302 TAILQ_REMOVE(&object->memq, m, listq);
3303 object->resident_page_count--;
3306 * Restore the default memory attribute to the page.
3308 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
3309 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
3312 * Insert the page into the object's collection of cached pages
3313 * and the physical memory allocator's cache/free page queues.
3315 m->flags &= ~PG_ZERO;
3316 mtx_lock(&vm_page_queue_free_mtx);
3317 cache_was_empty = vm_radix_is_empty(&object->cache);
3318 if (vm_radix_insert(&object->cache, m)) {
3319 mtx_unlock(&vm_page_queue_free_mtx);
3320 if (object->type == OBJT_VNODE &&
3321 object->resident_page_count == 0)
3322 vdrop(object->handle);
3329 * The above call to vm_radix_insert() could reclaim the one pre-
3330 * existing cached page from this object, resulting in a call to
3333 if (!cache_was_empty)
3334 cache_was_empty = vm_radix_is_singleton(&object->cache);
3336 m->flags |= PG_CACHED;
3337 vm_cnt.v_cache_count++;
3338 PCPU_INC(cnt.v_tcached);
3339 #if VM_NRESERVLEVEL > 0
3340 if (!vm_reserv_free_page(m)) {
3344 vm_phys_free_pages(m, 0);
3346 vm_page_free_wakeup();
3347 mtx_unlock(&vm_page_queue_free_mtx);
3350 * Increment the vnode's hold count if this is the object's only
3351 * cached page. Decrement the vnode's hold count if this was
3352 * the object's only resident page.
3354 if (object->type == OBJT_VNODE) {
3355 if (cache_was_empty && object->resident_page_count != 0)
3356 vhold(object->handle);
3357 else if (!cache_was_empty && object->resident_page_count == 0)
3358 vdrop(object->handle);
3365 * Deactivate or do nothing, as appropriate.
3367 * The object and page must be locked.
3370 vm_page_advise(vm_page_t m, int advice)
3373 vm_page_assert_locked(m);
3374 VM_OBJECT_ASSERT_WLOCKED(m->object);
3375 if (advice == MADV_FREE)
3377 * Mark the page clean. This will allow the page to be freed
3378 * up by the system. However, such pages are often reused
3379 * quickly by malloc() so we do not do anything that would
3380 * cause a page fault if we can help it.
3382 * Specifically, we do not try to actually free the page now
3383 * nor do we try to put it in the cache (which would cause a
3384 * page fault on reuse).
3386 * But we do make the page as freeable as we can without
3387 * actually taking the step of unmapping it.
3390 else if (advice != MADV_DONTNEED)
3394 * Clear any references to the page. Otherwise, the page daemon will
3395 * immediately reactivate the page.
3397 vm_page_aflag_clear(m, PGA_REFERENCED);
3399 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
3403 * Place clean pages near the head of the inactive queue rather than
3404 * the tail, thus defeating the queue's LRU operation and ensuring that
3405 * the page will be reused quickly. Dirty pages are given a chance to
3406 * cycle once through the inactive queue before becoming eligible for
3409 _vm_page_deactivate(m, m->dirty == 0);
3413 * Grab a page, waiting until we are waken up due to the page
3414 * changing state. We keep on waiting, if the page continues
3415 * to be in the object. If the page doesn't exist, first allocate it
3416 * and then conditionally zero it.
3418 * This routine may sleep.
3420 * The object must be locked on entry. The lock will, however, be released
3421 * and reacquired if the routine sleeps.
3424 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3429 VM_OBJECT_ASSERT_WLOCKED(object);
3430 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3431 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3432 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
3434 if ((m = vm_page_lookup(object, pindex)) != NULL) {
3435 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3436 vm_page_xbusied(m) : vm_page_busied(m);
3438 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3441 * Reference the page before unlocking and
3442 * sleeping so that the page daemon is less
3443 * likely to reclaim it.
3445 vm_page_aflag_set(m, PGA_REFERENCED);
3447 VM_OBJECT_WUNLOCK(object);
3448 vm_page_busy_sleep(m, "pgrbwt");
3449 VM_OBJECT_WLOCK(object);
3452 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3458 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
3460 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3465 m = vm_page_alloc(object, pindex, allocflags);
3467 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3469 VM_OBJECT_WUNLOCK(object);
3471 VM_OBJECT_WLOCK(object);
3473 } else if (m->valid != 0)
3475 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
3481 * Mapping function for valid or dirty bits in a page.
3483 * Inputs are required to range within a page.
3486 vm_page_bits(int base, int size)
3492 base + size <= PAGE_SIZE,
3493 ("vm_page_bits: illegal base/size %d/%d", base, size)
3496 if (size == 0) /* handle degenerate case */
3499 first_bit = base >> DEV_BSHIFT;
3500 last_bit = (base + size - 1) >> DEV_BSHIFT;
3502 return (((vm_page_bits_t)2 << last_bit) -
3503 ((vm_page_bits_t)1 << first_bit));
3507 * vm_page_set_valid_range:
3509 * Sets portions of a page valid. The arguments are expected
3510 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3511 * of any partial chunks touched by the range. The invalid portion of
3512 * such chunks will be zeroed.
3514 * (base + size) must be less then or equal to PAGE_SIZE.
3517 vm_page_set_valid_range(vm_page_t m, int base, int size)
3521 VM_OBJECT_ASSERT_WLOCKED(m->object);
3522 if (size == 0) /* handle degenerate case */
3526 * If the base is not DEV_BSIZE aligned and the valid
3527 * bit is clear, we have to zero out a portion of the
3530 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3531 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
3532 pmap_zero_page_area(m, frag, base - frag);
3535 * If the ending offset is not DEV_BSIZE aligned and the
3536 * valid bit is clear, we have to zero out a portion of
3539 endoff = base + size;
3540 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3541 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
3542 pmap_zero_page_area(m, endoff,
3543 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3546 * Assert that no previously invalid block that is now being validated
3549 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
3550 ("vm_page_set_valid_range: page %p is dirty", m));
3553 * Set valid bits inclusive of any overlap.
3555 m->valid |= vm_page_bits(base, size);
3559 * Clear the given bits from the specified page's dirty field.
3561 static __inline void
3562 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
3565 #if PAGE_SIZE < 16384
3570 * If the object is locked and the page is neither exclusive busy nor
3571 * write mapped, then the page's dirty field cannot possibly be
3572 * set by a concurrent pmap operation.
3574 VM_OBJECT_ASSERT_WLOCKED(m->object);
3575 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
3576 m->dirty &= ~pagebits;
3579 * The pmap layer can call vm_page_dirty() without
3580 * holding a distinguished lock. The combination of
3581 * the object's lock and an atomic operation suffice
3582 * to guarantee consistency of the page dirty field.
3584 * For PAGE_SIZE == 32768 case, compiler already
3585 * properly aligns the dirty field, so no forcible
3586 * alignment is needed. Only require existence of
3587 * atomic_clear_64 when page size is 32768.
3589 addr = (uintptr_t)&m->dirty;
3590 #if PAGE_SIZE == 32768
3591 atomic_clear_64((uint64_t *)addr, pagebits);
3592 #elif PAGE_SIZE == 16384
3593 atomic_clear_32((uint32_t *)addr, pagebits);
3594 #else /* PAGE_SIZE <= 8192 */
3596 * Use a trick to perform a 32-bit atomic on the
3597 * containing aligned word, to not depend on the existence
3598 * of atomic_clear_{8, 16}.
3600 shift = addr & (sizeof(uint32_t) - 1);
3601 #if BYTE_ORDER == BIG_ENDIAN
3602 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
3606 addr &= ~(sizeof(uint32_t) - 1);
3607 atomic_clear_32((uint32_t *)addr, pagebits << shift);
3608 #endif /* PAGE_SIZE */
3613 * vm_page_set_validclean:
3615 * Sets portions of a page valid and clean. The arguments are expected
3616 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3617 * of any partial chunks touched by the range. The invalid portion of
3618 * such chunks will be zero'd.
3620 * (base + size) must be less then or equal to PAGE_SIZE.
3623 vm_page_set_validclean(vm_page_t m, int base, int size)
3625 vm_page_bits_t oldvalid, pagebits;
3628 VM_OBJECT_ASSERT_WLOCKED(m->object);
3629 if (size == 0) /* handle degenerate case */
3633 * If the base is not DEV_BSIZE aligned and the valid
3634 * bit is clear, we have to zero out a portion of the
3637 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3638 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
3639 pmap_zero_page_area(m, frag, base - frag);
3642 * If the ending offset is not DEV_BSIZE aligned and the
3643 * valid bit is clear, we have to zero out a portion of
3646 endoff = base + size;
3647 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3648 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
3649 pmap_zero_page_area(m, endoff,
3650 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3653 * Set valid, clear dirty bits. If validating the entire
3654 * page we can safely clear the pmap modify bit. We also
3655 * use this opportunity to clear the VPO_NOSYNC flag. If a process
3656 * takes a write fault on a MAP_NOSYNC memory area the flag will
3659 * We set valid bits inclusive of any overlap, but we can only
3660 * clear dirty bits for DEV_BSIZE chunks that are fully within
3663 oldvalid = m->valid;
3664 pagebits = vm_page_bits(base, size);
3665 m->valid |= pagebits;
3667 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
3668 frag = DEV_BSIZE - frag;
3674 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
3676 if (base == 0 && size == PAGE_SIZE) {
3678 * The page can only be modified within the pmap if it is
3679 * mapped, and it can only be mapped if it was previously
3682 if (oldvalid == VM_PAGE_BITS_ALL)
3684 * Perform the pmap_clear_modify() first. Otherwise,
3685 * a concurrent pmap operation, such as
3686 * pmap_protect(), could clear a modification in the
3687 * pmap and set the dirty field on the page before
3688 * pmap_clear_modify() had begun and after the dirty
3689 * field was cleared here.
3691 pmap_clear_modify(m);
3693 m->oflags &= ~VPO_NOSYNC;
3694 } else if (oldvalid != VM_PAGE_BITS_ALL)
3695 m->dirty &= ~pagebits;
3697 vm_page_clear_dirty_mask(m, pagebits);
3701 vm_page_clear_dirty(vm_page_t m, int base, int size)
3704 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
3708 * vm_page_set_invalid:
3710 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3711 * valid and dirty bits for the effected areas are cleared.
3714 vm_page_set_invalid(vm_page_t m, int base, int size)
3716 vm_page_bits_t bits;
3720 VM_OBJECT_ASSERT_WLOCKED(object);
3721 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
3722 size >= object->un_pager.vnp.vnp_size)
3723 bits = VM_PAGE_BITS_ALL;
3725 bits = vm_page_bits(base, size);
3726 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL &&
3729 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
3730 !pmap_page_is_mapped(m),
3731 ("vm_page_set_invalid: page %p is mapped", m));
3737 * vm_page_zero_invalid()
3739 * The kernel assumes that the invalid portions of a page contain
3740 * garbage, but such pages can be mapped into memory by user code.
3741 * When this occurs, we must zero out the non-valid portions of the
3742 * page so user code sees what it expects.
3744 * Pages are most often semi-valid when the end of a file is mapped
3745 * into memory and the file's size is not page aligned.
3748 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3753 VM_OBJECT_ASSERT_WLOCKED(m->object);
3755 * Scan the valid bits looking for invalid sections that
3756 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
3757 * valid bit may be set ) have already been zeroed by
3758 * vm_page_set_validclean().
3760 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3761 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3762 (m->valid & ((vm_page_bits_t)1 << i))) {
3764 pmap_zero_page_area(m,
3765 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
3772 * setvalid is TRUE when we can safely set the zero'd areas
3773 * as being valid. We can do this if there are no cache consistancy
3774 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3777 m->valid = VM_PAGE_BITS_ALL;
3783 * Is (partial) page valid? Note that the case where size == 0
3784 * will return FALSE in the degenerate case where the page is
3785 * entirely invalid, and TRUE otherwise.
3788 vm_page_is_valid(vm_page_t m, int base, int size)
3790 vm_page_bits_t bits;
3792 VM_OBJECT_ASSERT_LOCKED(m->object);
3793 bits = vm_page_bits(base, size);
3794 return (m->valid != 0 && (m->valid & bits) == bits);
3798 * vm_page_ps_is_valid:
3800 * Returns TRUE if the entire (super)page is valid and FALSE otherwise.
3803 vm_page_ps_is_valid(vm_page_t m)
3807 VM_OBJECT_ASSERT_LOCKED(m->object);
3808 npages = atop(pagesizes[m->psind]);
3811 * The physically contiguous pages that make up a superpage, i.e., a
3812 * page with a page size index ("psind") greater than zero, will
3813 * occupy adjacent entries in vm_page_array[].
3815 for (i = 0; i < npages; i++) {
3816 if (m[i].valid != VM_PAGE_BITS_ALL)
3823 * Set the page's dirty bits if the page is modified.
3826 vm_page_test_dirty(vm_page_t m)
3829 VM_OBJECT_ASSERT_WLOCKED(m->object);
3830 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
3835 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
3838 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
3842 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
3845 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
3849 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
3852 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
3855 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
3857 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
3860 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
3864 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
3867 mtx_assert_(vm_page_lockptr(m), a, file, line);
3873 vm_page_object_lock_assert(vm_page_t m)
3877 * Certain of the page's fields may only be modified by the
3878 * holder of the containing object's lock or the exclusive busy.
3879 * holder. Unfortunately, the holder of the write busy is
3880 * not recorded, and thus cannot be checked here.
3882 if (m->object != NULL && !vm_page_xbusied(m))
3883 VM_OBJECT_ASSERT_WLOCKED(m->object);
3887 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits)
3890 if ((bits & PGA_WRITEABLE) == 0)
3894 * The PGA_WRITEABLE flag can only be set if the page is
3895 * managed, is exclusively busied or the object is locked.
3896 * Currently, this flag is only set by pmap_enter().
3898 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3899 ("PGA_WRITEABLE on unmanaged page"));
3900 if (!vm_page_xbusied(m))
3901 VM_OBJECT_ASSERT_LOCKED(m->object);
3905 #include "opt_ddb.h"
3907 #include <sys/kernel.h>
3909 #include <ddb/ddb.h>
3911 DB_SHOW_COMMAND(page, vm_page_print_page_info)
3913 db_printf("vm_cnt.v_free_count: %d\n", vm_cnt.v_free_count);
3914 db_printf("vm_cnt.v_cache_count: %d\n", vm_cnt.v_cache_count);
3915 db_printf("vm_cnt.v_inactive_count: %d\n", vm_cnt.v_inactive_count);
3916 db_printf("vm_cnt.v_active_count: %d\n", vm_cnt.v_active_count);
3917 db_printf("vm_cnt.v_wire_count: %d\n", vm_cnt.v_wire_count);
3918 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
3919 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
3920 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
3921 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
3924 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
3928 db_printf("pq_free %d pq_cache %d\n",
3929 vm_cnt.v_free_count, vm_cnt.v_cache_count);
3930 for (dom = 0; dom < vm_ndomains; dom++) {
3932 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pass %d\n",
3934 vm_dom[dom].vmd_page_count,
3935 vm_dom[dom].vmd_free_count,
3936 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
3937 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
3938 vm_dom[dom].vmd_pass);
3942 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
3948 db_printf("show pginfo addr\n");
3952 phys = strchr(modif, 'p') != NULL;
3954 m = PHYS_TO_VM_PAGE(addr);
3956 m = (vm_page_t)addr;
3958 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n"
3959 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
3960 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
3961 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags,
3962 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);