2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991 Regents of the University of California.
6 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
8 * This code is derived from software contributed to Berkeley by
9 * The Mach Operating System project at Carnegie-Mellon University.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
39 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40 * All rights reserved.
42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
44 * Permission to use, copy, modify and distribute this software and
45 * its documentation is hereby granted, provided that both the copyright
46 * notice and this permission notice appear in all copies of the
47 * software, derivative works or modified versions, and any portions
48 * thereof, and that both notices appear in supporting documentation.
50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54 * Carnegie Mellon requests users of this software to return to
56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
57 * School of Computer Science
58 * Carnegie Mellon University
59 * Pittsburgh PA 15213-3890
61 * any improvements or extensions that they make and grant Carnegie the
62 * rights to redistribute these changes.
66 * GENERAL RULES ON VM_PAGE MANIPULATION
68 * - A page queue lock is required when adding or removing a page from a
69 * page queue regardless of other locks or the busy state of a page.
71 * * In general, no thread besides the page daemon can acquire or
72 * hold more than one page queue lock at a time.
74 * * The page daemon can acquire and hold any pair of page queue
77 * - The object lock is required when inserting or removing
78 * pages from an object (vm_page_insert() or vm_page_remove()).
83 * Resident memory management module.
86 #include <sys/cdefs.h>
87 __FBSDID("$FreeBSD$");
91 #include <sys/param.h>
92 #include <sys/systm.h>
94 #include <sys/domainset.h>
95 #include <sys/kernel.h>
96 #include <sys/limits.h>
97 #include <sys/linker.h>
98 #include <sys/malloc.h>
100 #include <sys/msgbuf.h>
101 #include <sys/mutex.h>
102 #include <sys/proc.h>
103 #include <sys/rwlock.h>
104 #include <sys/sbuf.h>
106 #include <sys/sysctl.h>
107 #include <sys/vmmeter.h>
108 #include <sys/vnode.h>
112 #include <vm/vm_param.h>
113 #include <vm/vm_domainset.h>
114 #include <vm/vm_kern.h>
115 #include <vm/vm_map.h>
116 #include <vm/vm_object.h>
117 #include <vm/vm_page.h>
118 #include <vm/vm_pageout.h>
119 #include <vm/vm_phys.h>
120 #include <vm/vm_pagequeue.h>
121 #include <vm/vm_pager.h>
122 #include <vm/vm_radix.h>
123 #include <vm/vm_reserv.h>
124 #include <vm/vm_extern.h>
126 #include <vm/uma_int.h>
128 #include <machine/md_var.h>
130 extern int uma_startup_count(int);
131 extern void uma_startup(void *, int);
132 extern int vmem_startup_count(void);
135 * Associated with page of user-allocatable memory is a
139 struct vm_domain vm_dom[MAXMEMDOM];
141 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT];
143 struct mtx_padalign __exclusive_cache_line vm_domainset_lock;
144 /* The following fields are protected by the domainset lock. */
145 domainset_t __exclusive_cache_line vm_min_domains;
146 domainset_t __exclusive_cache_line vm_severe_domains;
147 static int vm_min_waiters;
148 static int vm_severe_waiters;
149 static int vm_pageproc_waiters;
152 * bogus page -- for I/O to/from partially complete buffers,
153 * or for paging into sparsely invalid regions.
155 vm_page_t bogus_page;
157 vm_page_t vm_page_array;
158 long vm_page_array_size;
161 static int boot_pages;
162 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
164 "number of pages allocated for bootstrapping the VM system");
166 static int pa_tryrelock_restart;
167 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
168 &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
170 static TAILQ_HEAD(, vm_page) blacklist_head;
171 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
172 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
173 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
175 static uma_zone_t fakepg_zone;
177 static void vm_page_alloc_check(vm_page_t m);
178 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
179 static void vm_page_enqueue(uint8_t queue, vm_page_t m);
180 static void vm_page_free_phys(struct vm_domain *vmd, vm_page_t m);
181 static void vm_page_init(void *dummy);
182 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
183 vm_pindex_t pindex, vm_page_t mpred);
184 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
186 static int vm_page_reclaim_run(int req_class, int domain, u_long npages,
187 vm_page_t m_run, vm_paddr_t high);
188 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object,
191 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL);
194 vm_page_init(void *dummy)
197 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
198 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
199 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ |
200 VM_ALLOC_NORMAL | VM_ALLOC_WIRED);
203 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
204 #if PAGE_SIZE == 32768
206 CTASSERT(sizeof(u_long) >= 8);
211 * Try to acquire a physical address lock while a pmap is locked. If we
212 * fail to trylock we unlock and lock the pmap directly and cache the
213 * locked pa in *locked. The caller should then restart their loop in case
214 * the virtual to physical mapping has changed.
217 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
224 PA_LOCK_ASSERT(lockpa, MA_OWNED);
225 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
232 atomic_add_int(&pa_tryrelock_restart, 1);
241 * Sets the page size, perhaps based upon the memory
242 * size. Must be called before any use of page-size
243 * dependent functions.
246 vm_set_page_size(void)
248 if (vm_cnt.v_page_size == 0)
249 vm_cnt.v_page_size = PAGE_SIZE;
250 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
251 panic("vm_set_page_size: page size not a power of two");
255 * vm_page_blacklist_next:
257 * Find the next entry in the provided string of blacklist
258 * addresses. Entries are separated by space, comma, or newline.
259 * If an invalid integer is encountered then the rest of the
260 * string is skipped. Updates the list pointer to the next
261 * character, or NULL if the string is exhausted or invalid.
264 vm_page_blacklist_next(char **list, char *end)
269 if (list == NULL || *list == NULL)
277 * If there's no end pointer then the buffer is coming from
278 * the kenv and we know it's null-terminated.
281 end = *list + strlen(*list);
283 /* Ensure that strtoq() won't walk off the end */
285 if (*end == '\n' || *end == ' ' || *end == ',')
288 printf("Blacklist not terminated, skipping\n");
294 for (pos = *list; *pos != '\0'; pos = cp) {
295 bad = strtoq(pos, &cp, 0);
296 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
305 if (*cp == '\0' || ++cp >= end)
309 return (trunc_page(bad));
311 printf("Garbage in RAM blacklist, skipping\n");
317 * vm_page_blacklist_check:
319 * Iterate through the provided string of blacklist addresses, pulling
320 * each entry out of the physical allocator free list and putting it
321 * onto a list for reporting via the vm.page_blacklist sysctl.
324 vm_page_blacklist_check(char *list, char *end)
326 struct vm_domain *vmd;
333 while (next != NULL) {
334 if ((pa = vm_page_blacklist_next(&next, end)) == 0)
336 m = vm_phys_paddr_to_vm_page(pa);
339 vmd = vm_pagequeue_domain(m);
340 vm_domain_free_lock(vmd);
341 ret = vm_phys_unfree_page(m);
342 vm_domain_free_unlock(vmd);
344 TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
346 printf("Skipping page with pa 0x%jx\n",
353 * vm_page_blacklist_load:
355 * Search for a special module named "ram_blacklist". It'll be a
356 * plain text file provided by the user via the loader directive
360 vm_page_blacklist_load(char **list, char **end)
369 mod = preload_search_by_type("ram_blacklist");
371 ptr = preload_fetch_addr(mod);
372 len = preload_fetch_size(mod);
383 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
390 error = sysctl_wire_old_buffer(req, 0);
393 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
394 TAILQ_FOREACH(m, &blacklist_head, listq) {
395 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
396 (uintmax_t)m->phys_addr);
399 error = sbuf_finish(&sbuf);
405 vm_page_domain_init(int domain)
407 struct vm_domain *vmd;
408 struct vm_pagequeue *pq;
411 vmd = VM_DOMAIN(domain);
412 bzero(vmd, sizeof(*vmd));
413 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
414 "vm inactive pagequeue";
415 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
416 "vm active pagequeue";
417 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) =
418 "vm laundry pagequeue";
419 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) =
420 "vm unswappable pagequeue";
421 vmd->vmd_domain = domain;
422 vmd->vmd_page_count = 0;
423 vmd->vmd_free_count = 0;
425 vmd->vmd_oom = FALSE;
426 for (i = 0; i < PQ_COUNT; i++) {
427 pq = &vmd->vmd_pagequeues[i];
428 TAILQ_INIT(&pq->pq_pl);
429 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
430 MTX_DEF | MTX_DUPOK);
432 mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF);
433 mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF);
434 snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain);
438 * Initialize a physical page in preparation for adding it to the free
442 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind)
447 m->busy_lock = VPB_UNBUSIED;
454 m->order = VM_NFREEORDER;
455 m->pool = VM_FREEPOOL_DEFAULT;
456 m->valid = m->dirty = 0;
463 * Initializes the resident memory module. Allocates physical memory for
464 * bootstrapping UMA and some data structures that are used to manage
465 * physical pages. Initializes these structures, and populates the free
469 vm_page_startup(vm_offset_t vaddr)
471 struct vm_phys_seg *seg;
473 char *list, *listend;
475 vm_paddr_t end, high_avail, low_avail, new_end, page_range, size;
476 vm_paddr_t biggestsize, last_pa, pa;
478 int biggestone, i, segind;
482 vaddr = round_page(vaddr);
484 for (i = 0; phys_avail[i + 1]; i += 2) {
485 phys_avail[i] = round_page(phys_avail[i]);
486 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
488 for (i = 0; phys_avail[i + 1]; i += 2) {
489 size = phys_avail[i + 1] - phys_avail[i];
490 if (size > biggestsize) {
496 end = phys_avail[biggestone+1];
499 * Initialize the page and queue locks.
501 mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF);
502 for (i = 0; i < PA_LOCK_COUNT; i++)
503 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
504 for (i = 0; i < vm_ndomains; i++)
505 vm_page_domain_init(i);
508 * Allocate memory for use when boot strapping the kernel memory
509 * allocator. Tell UMA how many zones we are going to create
510 * before going fully functional. UMA will add its zones.
512 * VM startup zones: vmem, vmem_btag, VM OBJECT, RADIX NODE, MAP,
513 * KMAP ENTRY, MAP ENTRY, VMSPACE.
515 boot_pages = uma_startup_count(8);
517 #ifndef UMA_MD_SMALL_ALLOC
518 /* vmem_startup() calls uma_prealloc(). */
519 boot_pages += vmem_startup_count();
520 /* vm_map_startup() calls uma_prealloc(). */
521 boot_pages += howmany(MAX_KMAP,
522 UMA_SLAB_SPACE / sizeof(struct vm_map));
525 * Before going fully functional kmem_init() does allocation
526 * from "KMAP ENTRY" and vmem_create() does allocation from "vmem".
531 * CTFLAG_RDTUN doesn't work during the early boot process, so we must
532 * manually fetch the value.
534 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages);
535 new_end = end - (boot_pages * UMA_SLAB_SIZE);
536 new_end = trunc_page(new_end);
537 mapped = pmap_map(&vaddr, new_end, end,
538 VM_PROT_READ | VM_PROT_WRITE);
539 bzero((void *)mapped, end - new_end);
540 uma_startup((void *)mapped, boot_pages);
542 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
543 defined(__i386__) || defined(__mips__)
545 * Allocate a bitmap to indicate that a random physical page
546 * needs to be included in a minidump.
548 * The amd64 port needs this to indicate which direct map pages
549 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
551 * However, i386 still needs this workspace internally within the
552 * minidump code. In theory, they are not needed on i386, but are
553 * included should the sf_buf code decide to use them.
556 for (i = 0; dump_avail[i + 1] != 0; i += 2)
557 if (dump_avail[i + 1] > last_pa)
558 last_pa = dump_avail[i + 1];
559 page_range = last_pa / PAGE_SIZE;
560 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
561 new_end -= vm_page_dump_size;
562 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
563 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
564 bzero((void *)vm_page_dump, vm_page_dump_size);
568 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
570 * Include the UMA bootstrap pages and vm_page_dump in a crash dump.
571 * When pmap_map() uses the direct map, they are not automatically
574 for (pa = new_end; pa < end; pa += PAGE_SIZE)
577 phys_avail[biggestone + 1] = new_end;
580 * Request that the physical pages underlying the message buffer be
581 * included in a crash dump. Since the message buffer is accessed
582 * through the direct map, they are not automatically included.
584 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
585 last_pa = pa + round_page(msgbufsize);
586 while (pa < last_pa) {
592 * Compute the number of pages of memory that will be available for
593 * use, taking into account the overhead of a page structure per page.
594 * In other words, solve
595 * "available physical memory" - round_page(page_range *
596 * sizeof(struct vm_page)) = page_range * PAGE_SIZE
599 low_avail = phys_avail[0];
600 high_avail = phys_avail[1];
601 for (i = 0; i < vm_phys_nsegs; i++) {
602 if (vm_phys_segs[i].start < low_avail)
603 low_avail = vm_phys_segs[i].start;
604 if (vm_phys_segs[i].end > high_avail)
605 high_avail = vm_phys_segs[i].end;
607 /* Skip the first chunk. It is already accounted for. */
608 for (i = 2; phys_avail[i + 1] != 0; i += 2) {
609 if (phys_avail[i] < low_avail)
610 low_avail = phys_avail[i];
611 if (phys_avail[i + 1] > high_avail)
612 high_avail = phys_avail[i + 1];
614 first_page = low_avail / PAGE_SIZE;
615 #ifdef VM_PHYSSEG_SPARSE
617 for (i = 0; i < vm_phys_nsegs; i++)
618 size += vm_phys_segs[i].end - vm_phys_segs[i].start;
619 for (i = 0; phys_avail[i + 1] != 0; i += 2)
620 size += phys_avail[i + 1] - phys_avail[i];
621 #elif defined(VM_PHYSSEG_DENSE)
622 size = high_avail - low_avail;
624 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
627 #ifdef VM_PHYSSEG_DENSE
629 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
630 * the overhead of a page structure per page only if vm_page_array is
631 * allocated from the last physical memory chunk. Otherwise, we must
632 * allocate page structures representing the physical memory
633 * underlying vm_page_array, even though they will not be used.
635 if (new_end != high_avail)
636 page_range = size / PAGE_SIZE;
640 page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
643 * If the partial bytes remaining are large enough for
644 * a page (PAGE_SIZE) without a corresponding
645 * 'struct vm_page', then new_end will contain an
646 * extra page after subtracting the length of the VM
647 * page array. Compensate by subtracting an extra
650 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
651 if (new_end == high_avail)
652 high_avail -= PAGE_SIZE;
653 new_end -= PAGE_SIZE;
659 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
660 * However, because this page is allocated from KVM, out-of-bounds
661 * accesses using the direct map will not be trapped.
666 * Allocate physical memory for the page structures, and map it.
668 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
669 mapped = pmap_map(&vaddr, new_end, end,
670 VM_PROT_READ | VM_PROT_WRITE);
671 vm_page_array = (vm_page_t)mapped;
672 vm_page_array_size = page_range;
674 #if VM_NRESERVLEVEL > 0
676 * Allocate physical memory for the reservation management system's
677 * data structures, and map it.
679 if (high_avail == end)
680 high_avail = new_end;
681 new_end = vm_reserv_startup(&vaddr, new_end, high_avail);
683 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
685 * Include vm_page_array and vm_reserv_array in a crash dump.
687 for (pa = new_end; pa < end; pa += PAGE_SIZE)
690 phys_avail[biggestone + 1] = new_end;
693 * Add physical memory segments corresponding to the available
696 for (i = 0; phys_avail[i + 1] != 0; i += 2)
697 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
700 * Initialize the physical memory allocator.
705 * Initialize the page structures and add every available page to the
706 * physical memory allocator's free lists.
708 vm_cnt.v_page_count = 0;
709 for (segind = 0; segind < vm_phys_nsegs; segind++) {
710 seg = &vm_phys_segs[segind];
711 for (m = seg->first_page, pa = seg->start; pa < seg->end;
712 m++, pa += PAGE_SIZE)
713 vm_page_init_page(m, pa, segind);
716 * Add the segment to the free lists only if it is covered by
717 * one of the ranges in phys_avail. Because we've added the
718 * ranges to the vm_phys_segs array, we can assume that each
719 * segment is either entirely contained in one of the ranges,
720 * or doesn't overlap any of them.
722 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
723 struct vm_domain *vmd;
725 if (seg->start < phys_avail[i] ||
726 seg->end > phys_avail[i + 1])
730 pagecount = (u_long)atop(seg->end - seg->start);
732 vmd = VM_DOMAIN(seg->domain);
733 vm_domain_free_lock(vmd);
734 vm_phys_free_contig(m, pagecount);
735 vm_domain_free_unlock(vmd);
736 vm_domain_freecnt_inc(vmd, pagecount);
737 vm_cnt.v_page_count += (u_int)pagecount;
739 vmd = VM_DOMAIN(seg->domain);
740 vmd->vmd_page_count += (u_int)pagecount;
741 vmd->vmd_segs |= 1UL << m->segind;
747 * Remove blacklisted pages from the physical memory allocator.
749 TAILQ_INIT(&blacklist_head);
750 vm_page_blacklist_load(&list, &listend);
751 vm_page_blacklist_check(list, listend);
753 list = kern_getenv("vm.blacklist");
754 vm_page_blacklist_check(list, NULL);
757 #if VM_NRESERVLEVEL > 0
759 * Initialize the reservation management system.
764 * Set an initial domain policy for thread0 so that allocations
773 vm_page_reference(vm_page_t m)
776 vm_page_aflag_set(m, PGA_REFERENCED);
780 * vm_page_busy_downgrade:
782 * Downgrade an exclusive busy page into a single shared busy page.
785 vm_page_busy_downgrade(vm_page_t m)
790 vm_page_assert_xbusied(m);
791 locked = mtx_owned(vm_page_lockptr(m));
795 x &= VPB_BIT_WAITERS;
796 if (x != 0 && !locked)
798 if (atomic_cmpset_rel_int(&m->busy_lock,
799 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1)))
801 if (x != 0 && !locked)
814 * Return a positive value if the page is shared busied, 0 otherwise.
817 vm_page_sbusied(vm_page_t m)
822 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
828 * Shared unbusy a page.
831 vm_page_sunbusy(vm_page_t m)
835 vm_page_lock_assert(m, MA_NOTOWNED);
836 vm_page_assert_sbusied(m);
840 if (VPB_SHARERS(x) > 1) {
841 if (atomic_cmpset_int(&m->busy_lock, x,
846 if ((x & VPB_BIT_WAITERS) == 0) {
847 KASSERT(x == VPB_SHARERS_WORD(1),
848 ("vm_page_sunbusy: invalid lock state"));
849 if (atomic_cmpset_int(&m->busy_lock,
850 VPB_SHARERS_WORD(1), VPB_UNBUSIED))
854 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS),
855 ("vm_page_sunbusy: invalid lock state for waiters"));
858 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) {
869 * vm_page_busy_sleep:
871 * Sleep and release the page lock, using the page pointer as wchan.
872 * This is used to implement the hard-path of busying mechanism.
874 * The given page must be locked.
876 * If nonshared is true, sleep only if the page is xbusy.
879 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared)
883 vm_page_assert_locked(m);
886 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) ||
887 ((x & VPB_BIT_WAITERS) == 0 &&
888 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) {
892 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0);
898 * Try to shared busy a page.
899 * If the operation succeeds 1 is returned otherwise 0.
900 * The operation never sleeps.
903 vm_page_trysbusy(vm_page_t m)
909 if ((x & VPB_BIT_SHARED) == 0)
911 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER))
917 vm_page_xunbusy_locked(vm_page_t m)
920 vm_page_assert_xbusied(m);
921 vm_page_assert_locked(m);
923 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
924 /* There is a waiter, do wakeup() instead of vm_page_flash(). */
929 vm_page_xunbusy_maybelocked(vm_page_t m)
933 vm_page_assert_xbusied(m);
936 * Fast path for unbusy. If it succeeds, we know that there
937 * are no waiters, so we do not need a wakeup.
939 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER,
943 lockacq = !mtx_owned(vm_page_lockptr(m));
946 vm_page_xunbusy_locked(m);
952 * vm_page_xunbusy_hard:
954 * Called after the first try the exclusive unbusy of a page failed.
955 * It is assumed that the waiters bit is on.
958 vm_page_xunbusy_hard(vm_page_t m)
961 vm_page_assert_xbusied(m);
964 vm_page_xunbusy_locked(m);
971 * Wakeup anyone waiting for the page.
972 * The ownership bits do not change.
974 * The given page must be locked.
977 vm_page_flash(vm_page_t m)
981 vm_page_lock_assert(m, MA_OWNED);
985 if ((x & VPB_BIT_WAITERS) == 0)
987 if (atomic_cmpset_int(&m->busy_lock, x,
988 x & (~VPB_BIT_WAITERS)))
995 * Avoid releasing and reacquiring the same page lock.
998 vm_page_change_lock(vm_page_t m, struct mtx **mtx)
1002 mtx1 = vm_page_lockptr(m);
1012 * Keep page from being freed by the page daemon
1013 * much of the same effect as wiring, except much lower
1014 * overhead and should be used only for *very* temporary
1015 * holding ("wiring").
1018 vm_page_hold(vm_page_t mem)
1021 vm_page_lock_assert(mem, MA_OWNED);
1026 vm_page_unhold(vm_page_t mem)
1029 vm_page_lock_assert(mem, MA_OWNED);
1030 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!"));
1032 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0)
1033 vm_page_free_toq(mem);
1037 * vm_page_unhold_pages:
1039 * Unhold each of the pages that is referenced by the given array.
1042 vm_page_unhold_pages(vm_page_t *ma, int count)
1047 for (; count != 0; count--) {
1048 vm_page_change_lock(*ma, &mtx);
1049 vm_page_unhold(*ma);
1057 PHYS_TO_VM_PAGE(vm_paddr_t pa)
1061 #ifdef VM_PHYSSEG_SPARSE
1062 m = vm_phys_paddr_to_vm_page(pa);
1064 m = vm_phys_fictitious_to_vm_page(pa);
1066 #elif defined(VM_PHYSSEG_DENSE)
1070 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1071 m = &vm_page_array[pi - first_page];
1074 return (vm_phys_fictitious_to_vm_page(pa));
1076 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
1083 * Create a fictitious page with the specified physical address and
1084 * memory attribute. The memory attribute is the only the machine-
1085 * dependent aspect of a fictitious page that must be initialized.
1088 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1092 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1093 vm_page_initfake(m, paddr, memattr);
1098 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1101 if ((m->flags & PG_FICTITIOUS) != 0) {
1103 * The page's memattr might have changed since the
1104 * previous initialization. Update the pmap to the
1109 m->phys_addr = paddr;
1111 /* Fictitious pages don't use "segind". */
1112 m->flags = PG_FICTITIOUS;
1113 /* Fictitious pages don't use "order" or "pool". */
1114 m->oflags = VPO_UNMANAGED;
1115 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1119 pmap_page_set_memattr(m, memattr);
1125 * Release a fictitious page.
1128 vm_page_putfake(vm_page_t m)
1131 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1132 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1133 ("vm_page_putfake: bad page %p", m));
1134 uma_zfree(fakepg_zone, m);
1138 * vm_page_updatefake:
1140 * Update the given fictitious page to the specified physical address and
1144 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1147 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1148 ("vm_page_updatefake: bad page %p", m));
1149 m->phys_addr = paddr;
1150 pmap_page_set_memattr(m, memattr);
1159 vm_page_free(vm_page_t m)
1162 m->flags &= ~PG_ZERO;
1163 vm_page_free_toq(m);
1167 * vm_page_free_zero:
1169 * Free a page to the zerod-pages queue
1172 vm_page_free_zero(vm_page_t m)
1175 m->flags |= PG_ZERO;
1176 vm_page_free_toq(m);
1180 * Unbusy and handle the page queueing for a page from a getpages request that
1181 * was optionally read ahead or behind.
1184 vm_page_readahead_finish(vm_page_t m)
1187 /* We shouldn't put invalid pages on queues. */
1188 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
1191 * Since the page is not the actually needed one, whether it should
1192 * be activated or deactivated is not obvious. Empirical results
1193 * have shown that deactivating the page is usually the best choice,
1194 * unless the page is wanted by another thread.
1197 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
1198 vm_page_activate(m);
1200 vm_page_deactivate(m);
1206 * vm_page_sleep_if_busy:
1208 * Sleep and release the page queues lock if the page is busied.
1209 * Returns TRUE if the thread slept.
1211 * The given page must be unlocked and object containing it must
1215 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
1219 vm_page_lock_assert(m, MA_NOTOWNED);
1220 VM_OBJECT_ASSERT_WLOCKED(m->object);
1222 if (vm_page_busied(m)) {
1224 * The page-specific object must be cached because page
1225 * identity can change during the sleep, causing the
1226 * re-lock of a different object.
1227 * It is assumed that a reference to the object is already
1228 * held by the callers.
1232 VM_OBJECT_WUNLOCK(obj);
1233 vm_page_busy_sleep(m, msg, false);
1234 VM_OBJECT_WLOCK(obj);
1241 * vm_page_dirty_KBI: [ internal use only ]
1243 * Set all bits in the page's dirty field.
1245 * The object containing the specified page must be locked if the
1246 * call is made from the machine-independent layer.
1248 * See vm_page_clear_dirty_mask().
1250 * This function should only be called by vm_page_dirty().
1253 vm_page_dirty_KBI(vm_page_t m)
1256 /* Refer to this operation by its public name. */
1257 KASSERT(m->valid == VM_PAGE_BITS_ALL,
1258 ("vm_page_dirty: page is invalid!"));
1259 m->dirty = VM_PAGE_BITS_ALL;
1263 * vm_page_insert: [ internal use only ]
1265 * Inserts the given mem entry into the object and object list.
1267 * The object must be locked.
1270 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1274 VM_OBJECT_ASSERT_WLOCKED(object);
1275 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1276 return (vm_page_insert_after(m, object, pindex, mpred));
1280 * vm_page_insert_after:
1282 * Inserts the page "m" into the specified object at offset "pindex".
1284 * The page "mpred" must immediately precede the offset "pindex" within
1285 * the specified object.
1287 * The object must be locked.
1290 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1295 VM_OBJECT_ASSERT_WLOCKED(object);
1296 KASSERT(m->object == NULL,
1297 ("vm_page_insert_after: page already inserted"));
1298 if (mpred != NULL) {
1299 KASSERT(mpred->object == object,
1300 ("vm_page_insert_after: object doesn't contain mpred"));
1301 KASSERT(mpred->pindex < pindex,
1302 ("vm_page_insert_after: mpred doesn't precede pindex"));
1303 msucc = TAILQ_NEXT(mpred, listq);
1305 msucc = TAILQ_FIRST(&object->memq);
1307 KASSERT(msucc->pindex > pindex,
1308 ("vm_page_insert_after: msucc doesn't succeed pindex"));
1311 * Record the object/offset pair in this page
1317 * Now link into the object's ordered list of backed pages.
1319 if (vm_radix_insert(&object->rtree, m)) {
1324 vm_page_insert_radixdone(m, object, mpred);
1329 * vm_page_insert_radixdone:
1331 * Complete page "m" insertion into the specified object after the
1332 * radix trie hooking.
1334 * The page "mpred" must precede the offset "m->pindex" within the
1337 * The object must be locked.
1340 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1343 VM_OBJECT_ASSERT_WLOCKED(object);
1344 KASSERT(object != NULL && m->object == object,
1345 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1346 if (mpred != NULL) {
1347 KASSERT(mpred->object == object,
1348 ("vm_page_insert_after: object doesn't contain mpred"));
1349 KASSERT(mpred->pindex < m->pindex,
1350 ("vm_page_insert_after: mpred doesn't precede pindex"));
1354 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1356 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1359 * Show that the object has one more resident page.
1361 object->resident_page_count++;
1364 * Hold the vnode until the last page is released.
1366 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1367 vhold(object->handle);
1370 * Since we are inserting a new and possibly dirty page,
1371 * update the object's OBJ_MIGHTBEDIRTY flag.
1373 if (pmap_page_is_write_mapped(m))
1374 vm_object_set_writeable_dirty(object);
1380 * Removes the specified page from its containing object, but does not
1381 * invalidate any backing storage.
1383 * The object must be locked. The page must be locked if it is managed.
1386 vm_page_remove(vm_page_t m)
1391 if ((m->oflags & VPO_UNMANAGED) == 0)
1392 vm_page_assert_locked(m);
1393 if ((object = m->object) == NULL)
1395 VM_OBJECT_ASSERT_WLOCKED(object);
1396 if (vm_page_xbusied(m))
1397 vm_page_xunbusy_maybelocked(m);
1398 mrem = vm_radix_remove(&object->rtree, m->pindex);
1399 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1402 * Now remove from the object's list of backed pages.
1404 TAILQ_REMOVE(&object->memq, m, listq);
1407 * And show that the object has one fewer resident page.
1409 object->resident_page_count--;
1412 * The vnode may now be recycled.
1414 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1415 vdrop(object->handle);
1423 * Returns the page associated with the object/offset
1424 * pair specified; if none is found, NULL is returned.
1426 * The object must be locked.
1429 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1432 VM_OBJECT_ASSERT_LOCKED(object);
1433 return (vm_radix_lookup(&object->rtree, pindex));
1437 * vm_page_find_least:
1439 * Returns the page associated with the object with least pindex
1440 * greater than or equal to the parameter pindex, or NULL.
1442 * The object must be locked.
1445 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1449 VM_OBJECT_ASSERT_LOCKED(object);
1450 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1451 m = vm_radix_lookup_ge(&object->rtree, pindex);
1456 * Returns the given page's successor (by pindex) within the object if it is
1457 * resident; if none is found, NULL is returned.
1459 * The object must be locked.
1462 vm_page_next(vm_page_t m)
1466 VM_OBJECT_ASSERT_LOCKED(m->object);
1467 if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1468 MPASS(next->object == m->object);
1469 if (next->pindex != m->pindex + 1)
1476 * Returns the given page's predecessor (by pindex) within the object if it is
1477 * resident; if none is found, NULL is returned.
1479 * The object must be locked.
1482 vm_page_prev(vm_page_t m)
1486 VM_OBJECT_ASSERT_LOCKED(m->object);
1487 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1488 MPASS(prev->object == m->object);
1489 if (prev->pindex != m->pindex - 1)
1496 * Uses the page mnew as a replacement for an existing page at index
1497 * pindex which must be already present in the object.
1499 * The existing page must not be on a paging queue.
1502 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1506 VM_OBJECT_ASSERT_WLOCKED(object);
1507 KASSERT(mnew->object == NULL,
1508 ("vm_page_replace: page %p already in object", mnew));
1509 KASSERT(mnew->queue == PQ_NONE,
1510 ("vm_page_replace: new page %p is on a paging queue", mnew));
1513 * This function mostly follows vm_page_insert() and
1514 * vm_page_remove() without the radix, object count and vnode
1515 * dance. Double check such functions for more comments.
1518 mnew->object = object;
1519 mnew->pindex = pindex;
1520 mold = vm_radix_replace(&object->rtree, mnew);
1521 KASSERT(mold->queue == PQ_NONE,
1522 ("vm_page_replace: old page %p is on a paging queue", mold));
1524 /* Keep the resident page list in sorted order. */
1525 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1526 TAILQ_REMOVE(&object->memq, mold, listq);
1528 mold->object = NULL;
1529 vm_page_xunbusy_maybelocked(mold);
1532 * The object's resident_page_count does not change because we have
1533 * swapped one page for another, but OBJ_MIGHTBEDIRTY.
1535 if (pmap_page_is_write_mapped(mnew))
1536 vm_object_set_writeable_dirty(object);
1543 * Move the given memory entry from its
1544 * current object to the specified target object/offset.
1546 * Note: swap associated with the page must be invalidated by the move. We
1547 * have to do this for several reasons: (1) we aren't freeing the
1548 * page, (2) we are dirtying the page, (3) the VM system is probably
1549 * moving the page from object A to B, and will then later move
1550 * the backing store from A to B and we can't have a conflict.
1552 * Note: we *always* dirty the page. It is necessary both for the
1553 * fact that we moved it, and because we may be invalidating
1556 * The objects must be locked.
1559 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1564 VM_OBJECT_ASSERT_WLOCKED(new_object);
1566 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1567 KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1568 ("vm_page_rename: pindex already renamed"));
1571 * Create a custom version of vm_page_insert() which does not depend
1572 * by m_prev and can cheat on the implementation aspects of the
1576 m->pindex = new_pindex;
1577 if (vm_radix_insert(&new_object->rtree, m)) {
1583 * The operation cannot fail anymore. The removal must happen before
1584 * the listq iterator is tainted.
1590 /* Return back to the new pindex to complete vm_page_insert(). */
1591 m->pindex = new_pindex;
1592 m->object = new_object;
1594 vm_page_insert_radixdone(m, new_object, mpred);
1602 * Allocate and return a page that is associated with the specified
1603 * object and offset pair. By default, this page is exclusive busied.
1605 * The caller must always specify an allocation class.
1607 * allocation classes:
1608 * VM_ALLOC_NORMAL normal process request
1609 * VM_ALLOC_SYSTEM system *really* needs a page
1610 * VM_ALLOC_INTERRUPT interrupt time request
1612 * optional allocation flags:
1613 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1614 * intends to allocate
1615 * VM_ALLOC_NOBUSY do not exclusive busy the page
1616 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1617 * VM_ALLOC_NOOBJ page is not associated with an object and
1618 * should not be exclusive busy
1619 * VM_ALLOC_SBUSY shared busy the allocated page
1620 * VM_ALLOC_WIRED wire the allocated page
1621 * VM_ALLOC_ZERO prefer a zeroed page
1624 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1627 return (vm_page_alloc_after(object, pindex, req, object != NULL ?
1628 vm_radix_lookup_le(&object->rtree, pindex) : NULL));
1632 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1636 return (vm_page_alloc_domain_after(object, pindex, domain, req,
1637 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) :
1642 * Allocate a page in the specified object with the given page index. To
1643 * optimize insertion of the page into the object, the caller must also specifiy
1644 * the resident page in the object with largest index smaller than the given
1645 * page index, or NULL if no such page exists.
1648 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex,
1649 int req, vm_page_t mpred)
1651 struct vm_domainset_iter di;
1655 vm_domainset_iter_page_init(&di, object, &domain, &req);
1657 m = vm_page_alloc_domain_after(object, pindex, domain, req,
1661 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
1667 * Returns true if the number of free pages exceeds the minimum
1668 * for the request class and false otherwise.
1671 vm_domain_available(struct vm_domain *vmd, int req, int npages)
1674 vm_domain_free_assert_locked(vmd);
1675 req = req & VM_ALLOC_CLASS_MASK;
1678 * The page daemon is allowed to dig deeper into the free page list.
1680 if (curproc == pageproc && req != VM_ALLOC_INTERRUPT)
1681 req = VM_ALLOC_SYSTEM;
1683 if (vmd->vmd_free_count >= npages + vmd->vmd_free_reserved ||
1684 (req == VM_ALLOC_SYSTEM &&
1685 vmd->vmd_free_count >= npages + vmd->vmd_interrupt_free_min) ||
1686 (req == VM_ALLOC_INTERRUPT &&
1687 vmd->vmd_free_count >= npages))
1694 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
1695 int req, vm_page_t mpred)
1697 struct vm_domain *vmd;
1701 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1702 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1703 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1704 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1705 ("inconsistent object(%p)/req(%x)", object, req));
1706 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
1707 ("Can't sleep and retry object insertion."));
1708 KASSERT(mpred == NULL || mpred->pindex < pindex,
1709 ("mpred %p doesn't precede pindex 0x%jx", mpred,
1710 (uintmax_t)pindex));
1712 VM_OBJECT_ASSERT_WLOCKED(object);
1716 #if VM_NRESERVLEVEL > 0
1717 if (vm_object_reserv(object) &&
1718 (m = vm_reserv_extend(req, object, pindex, domain, mpred))
1720 domain = vm_phys_domain(m);
1721 vmd = VM_DOMAIN(domain);
1725 vmd = VM_DOMAIN(domain);
1726 vm_domain_free_lock(vmd);
1727 if (vm_domain_available(vmd, req, 1)) {
1729 * Can we allocate the page from a reservation?
1731 #if VM_NRESERVLEVEL > 0
1732 if (!vm_object_reserv(object) ||
1733 (m = vm_reserv_alloc_page(object, pindex,
1734 domain, mpred)) == NULL)
1738 * If not, allocate it from the free page queues.
1740 m = vm_phys_alloc_pages(domain, object != NULL ?
1741 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1742 #if VM_NRESERVLEVEL > 0
1743 if (m == NULL && vm_reserv_reclaim_inactive(domain)) {
1744 m = vm_phys_alloc_pages(domain,
1746 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1753 vm_domain_freecnt_dec(vmd, 1);
1754 vm_domain_free_unlock(vmd);
1757 * Not allocatable, give up.
1759 if (vm_domain_alloc_fail(vmd, object, req))
1765 * At this point we had better have found a good page.
1767 KASSERT(m != NULL, ("missing page"));
1769 #if VM_NRESERVLEVEL > 0
1772 vm_page_alloc_check(m);
1775 * Initialize the page. Only the PG_ZERO flag is inherited.
1778 if ((req & VM_ALLOC_ZERO) != 0)
1781 if ((req & VM_ALLOC_NODUMP) != 0)
1785 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1787 m->busy_lock = VPB_UNBUSIED;
1788 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1789 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1790 if ((req & VM_ALLOC_SBUSY) != 0)
1791 m->busy_lock = VPB_SHARERS_WORD(1);
1792 if (req & VM_ALLOC_WIRED) {
1794 * The page lock is not required for wiring a page until that
1795 * page is inserted into the object.
1802 if (object != NULL) {
1803 if (vm_page_insert_after(m, object, pindex, mpred)) {
1804 if (req & VM_ALLOC_WIRED) {
1808 KASSERT(m->object == NULL, ("page %p has object", m));
1809 m->oflags = VPO_UNMANAGED;
1810 m->busy_lock = VPB_UNBUSIED;
1811 /* Don't change PG_ZERO. */
1812 vm_page_free_toq(m);
1813 if (req & VM_ALLOC_WAITFAIL) {
1814 VM_OBJECT_WUNLOCK(object);
1816 VM_OBJECT_WLOCK(object);
1821 /* Ignore device objects; the pager sets "memattr" for them. */
1822 if (object->memattr != VM_MEMATTR_DEFAULT &&
1823 (object->flags & OBJ_FICTITIOUS) == 0)
1824 pmap_page_set_memattr(m, object->memattr);
1832 * vm_page_alloc_contig:
1834 * Allocate a contiguous set of physical pages of the given size "npages"
1835 * from the free lists. All of the physical pages must be at or above
1836 * the given physical address "low" and below the given physical address
1837 * "high". The given value "alignment" determines the alignment of the
1838 * first physical page in the set. If the given value "boundary" is
1839 * non-zero, then the set of physical pages cannot cross any physical
1840 * address boundary that is a multiple of that value. Both "alignment"
1841 * and "boundary" must be a power of two.
1843 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1844 * then the memory attribute setting for the physical pages is configured
1845 * to the object's memory attribute setting. Otherwise, the memory
1846 * attribute setting for the physical pages is configured to "memattr",
1847 * overriding the object's memory attribute setting. However, if the
1848 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1849 * memory attribute setting for the physical pages cannot be configured
1850 * to VM_MEMATTR_DEFAULT.
1852 * The specified object may not contain fictitious pages.
1854 * The caller must always specify an allocation class.
1856 * allocation classes:
1857 * VM_ALLOC_NORMAL normal process request
1858 * VM_ALLOC_SYSTEM system *really* needs a page
1859 * VM_ALLOC_INTERRUPT interrupt time request
1861 * optional allocation flags:
1862 * VM_ALLOC_NOBUSY do not exclusive busy the page
1863 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1864 * VM_ALLOC_NOOBJ page is not associated with an object and
1865 * should not be exclusive busy
1866 * VM_ALLOC_SBUSY shared busy the allocated page
1867 * VM_ALLOC_WIRED wire the allocated page
1868 * VM_ALLOC_ZERO prefer a zeroed page
1871 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1872 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1873 vm_paddr_t boundary, vm_memattr_t memattr)
1875 struct vm_domainset_iter di;
1879 vm_domainset_iter_page_init(&di, object, &domain, &req);
1881 m = vm_page_alloc_contig_domain(object, pindex, domain, req,
1882 npages, low, high, alignment, boundary, memattr);
1885 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
1891 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1892 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1893 vm_paddr_t boundary, vm_memattr_t memattr)
1895 struct vm_domain *vmd;
1896 vm_page_t m, m_ret, mpred;
1897 u_int busy_lock, flags, oflags;
1899 mpred = NULL; /* XXX: pacify gcc */
1900 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1901 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1902 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1903 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1904 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
1906 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
1907 ("Can't sleep and retry object insertion."));
1908 if (object != NULL) {
1909 VM_OBJECT_ASSERT_WLOCKED(object);
1910 KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
1911 ("vm_page_alloc_contig: object %p has fictitious pages",
1914 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
1916 if (object != NULL) {
1917 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1918 KASSERT(mpred == NULL || mpred->pindex != pindex,
1919 ("vm_page_alloc_contig: pindex already allocated"));
1923 * Can we allocate the pages without the number of free pages falling
1924 * below the lower bound for the allocation class?
1927 #if VM_NRESERVLEVEL > 0
1928 if (vm_object_reserv(object) &&
1929 (m_ret = vm_reserv_extend_contig(req, object, pindex, domain,
1930 npages, low, high, alignment, boundary, mpred)) != NULL) {
1931 domain = vm_phys_domain(m_ret);
1932 vmd = VM_DOMAIN(domain);
1937 vmd = VM_DOMAIN(domain);
1938 vm_domain_free_lock(vmd);
1939 if (vm_domain_available(vmd, req, npages)) {
1941 * Can we allocate the pages from a reservation?
1943 #if VM_NRESERVLEVEL > 0
1945 if (!vm_object_reserv(object) ||
1946 (m_ret = vm_reserv_alloc_contig(object, pindex, domain,
1947 npages, low, high, alignment, boundary, mpred)) == NULL)
1950 * If not, allocate them from the free page queues.
1952 m_ret = vm_phys_alloc_contig(domain, npages, low, high,
1953 alignment, boundary);
1954 #if VM_NRESERVLEVEL > 0
1955 if (m_ret == NULL && vm_reserv_reclaim_contig(
1956 domain, npages, low, high, alignment, boundary))
1961 vm_domain_freecnt_dec(vmd, npages);
1962 vm_domain_free_unlock(vmd);
1963 if (m_ret == NULL) {
1964 if (vm_domain_alloc_fail(vmd, object, req))
1968 #if VM_NRESERVLEVEL > 0
1971 for (m = m_ret; m < &m_ret[npages]; m++)
1972 vm_page_alloc_check(m);
1975 * Initialize the pages. Only the PG_ZERO flag is inherited.
1978 if ((req & VM_ALLOC_ZERO) != 0)
1980 if ((req & VM_ALLOC_NODUMP) != 0)
1982 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1984 busy_lock = VPB_UNBUSIED;
1985 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1986 busy_lock = VPB_SINGLE_EXCLUSIVER;
1987 if ((req & VM_ALLOC_SBUSY) != 0)
1988 busy_lock = VPB_SHARERS_WORD(1);
1989 if ((req & VM_ALLOC_WIRED) != 0)
1990 vm_wire_add(npages);
1991 if (object != NULL) {
1992 if (object->memattr != VM_MEMATTR_DEFAULT &&
1993 memattr == VM_MEMATTR_DEFAULT)
1994 memattr = object->memattr;
1996 for (m = m_ret; m < &m_ret[npages]; m++) {
1998 m->flags = (m->flags | PG_NODUMP) & flags;
1999 m->busy_lock = busy_lock;
2000 if ((req & VM_ALLOC_WIRED) != 0)
2004 if (object != NULL) {
2005 if (vm_page_insert_after(m, object, pindex, mpred)) {
2006 if ((req & VM_ALLOC_WIRED) != 0)
2007 vm_wire_sub(npages);
2008 KASSERT(m->object == NULL,
2009 ("page %p has object", m));
2011 for (m = m_ret; m < &m_ret[npages]; m++) {
2013 (req & VM_ALLOC_WIRED) != 0)
2015 m->oflags = VPO_UNMANAGED;
2016 m->busy_lock = VPB_UNBUSIED;
2017 /* Don't change PG_ZERO. */
2018 vm_page_free_toq(m);
2020 if (req & VM_ALLOC_WAITFAIL) {
2021 VM_OBJECT_WUNLOCK(object);
2023 VM_OBJECT_WLOCK(object);
2030 if (memattr != VM_MEMATTR_DEFAULT)
2031 pmap_page_set_memattr(m, memattr);
2038 * Check a page that has been freshly dequeued from a freelist.
2041 vm_page_alloc_check(vm_page_t m)
2044 KASSERT(m->object == NULL, ("page %p has object", m));
2045 KASSERT(m->queue == PQ_NONE,
2046 ("page %p has unexpected queue %d", m, m->queue));
2047 KASSERT(!vm_page_held(m), ("page %p is held", m));
2048 KASSERT(!vm_page_busied(m), ("page %p is busy", m));
2049 KASSERT(m->dirty == 0, ("page %p is dirty", m));
2050 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2051 ("page %p has unexpected memattr %d",
2052 m, pmap_page_get_memattr(m)));
2053 KASSERT(m->valid == 0, ("free page %p is valid", m));
2057 * vm_page_alloc_freelist:
2059 * Allocate a physical page from the specified free page list.
2061 * The caller must always specify an allocation class.
2063 * allocation classes:
2064 * VM_ALLOC_NORMAL normal process request
2065 * VM_ALLOC_SYSTEM system *really* needs a page
2066 * VM_ALLOC_INTERRUPT interrupt time request
2068 * optional allocation flags:
2069 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
2070 * intends to allocate
2071 * VM_ALLOC_WIRED wire the allocated page
2072 * VM_ALLOC_ZERO prefer a zeroed page
2075 vm_page_alloc_freelist(int freelist, int req)
2077 struct vm_domainset_iter di;
2081 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req);
2083 m = vm_page_alloc_freelist_domain(domain, freelist, req);
2086 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
2092 vm_page_alloc_freelist_domain(int domain, int freelist, int req)
2094 struct vm_domain *vmd;
2099 * Do not allocate reserved pages unless the req has asked for it.
2101 vmd = VM_DOMAIN(domain);
2103 vm_domain_free_lock(vmd);
2104 if (vm_domain_available(vmd, req, 1))
2105 m = vm_phys_alloc_freelist_pages(domain, freelist,
2106 VM_FREEPOOL_DIRECT, 0);
2108 vm_domain_freecnt_dec(vmd, 1);
2109 vm_domain_free_unlock(vmd);
2111 if (vm_domain_alloc_fail(vmd, NULL, req))
2115 vm_page_alloc_check(m);
2118 * Initialize the page. Only the PG_ZERO flag is inherited.
2122 if ((req & VM_ALLOC_ZERO) != 0)
2125 if ((req & VM_ALLOC_WIRED) != 0) {
2127 * The page lock is not required for wiring a page that does
2128 * not belong to an object.
2133 /* Unmanaged pages don't use "act_count". */
2134 m->oflags = VPO_UNMANAGED;
2138 #define VPSC_ANY 0 /* No restrictions. */
2139 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
2140 #define VPSC_NOSUPER 2 /* Skip superpages. */
2143 * vm_page_scan_contig:
2145 * Scan vm_page_array[] between the specified entries "m_start" and
2146 * "m_end" for a run of contiguous physical pages that satisfy the
2147 * specified conditions, and return the lowest page in the run. The
2148 * specified "alignment" determines the alignment of the lowest physical
2149 * page in the run. If the specified "boundary" is non-zero, then the
2150 * run of physical pages cannot span a physical address that is a
2151 * multiple of "boundary".
2153 * "m_end" is never dereferenced, so it need not point to a vm_page
2154 * structure within vm_page_array[].
2156 * "npages" must be greater than zero. "m_start" and "m_end" must not
2157 * span a hole (or discontiguity) in the physical address space. Both
2158 * "alignment" and "boundary" must be a power of two.
2161 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2162 u_long alignment, vm_paddr_t boundary, int options)
2168 #if VM_NRESERVLEVEL > 0
2171 int m_inc, order, run_ext, run_len;
2173 KASSERT(npages > 0, ("npages is 0"));
2174 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2175 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2179 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2180 KASSERT((m->flags & PG_MARKER) == 0,
2181 ("page %p is PG_MARKER", m));
2182 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->wire_count == 1,
2183 ("fictitious page %p has invalid wire count", m));
2186 * If the current page would be the start of a run, check its
2187 * physical address against the end, alignment, and boundary
2188 * conditions. If it doesn't satisfy these conditions, either
2189 * terminate the scan or advance to the next page that
2190 * satisfies the failed condition.
2193 KASSERT(m_run == NULL, ("m_run != NULL"));
2194 if (m + npages > m_end)
2196 pa = VM_PAGE_TO_PHYS(m);
2197 if ((pa & (alignment - 1)) != 0) {
2198 m_inc = atop(roundup2(pa, alignment) - pa);
2201 if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
2203 m_inc = atop(roundup2(pa, boundary) - pa);
2207 KASSERT(m_run != NULL, ("m_run == NULL"));
2209 vm_page_change_lock(m, &m_mtx);
2212 if (vm_page_held(m))
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 (vm_page_held(m)) {
2245 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2246 ("page %p is PG_UNHOLDFREE", m));
2247 /* Don't care: PG_NODUMP, PG_ZERO. */
2248 if (object->type != OBJT_DEFAULT &&
2249 object->type != OBJT_SWAP &&
2250 object->type != OBJT_VNODE) {
2252 #if VM_NRESERVLEVEL > 0
2253 } else if ((options & VPSC_NOSUPER) != 0 &&
2254 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2256 /* Advance to the end of the superpage. */
2257 pa = VM_PAGE_TO_PHYS(m);
2258 m_inc = atop(roundup2(pa + 1,
2259 vm_reserv_size(level)) - pa);
2261 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2262 m->queue != PQ_NONE && !vm_page_busied(m)) {
2264 * The page is allocated but eligible for
2265 * relocation. Extend the current run by one
2268 KASSERT(pmap_page_get_memattr(m) ==
2270 ("page %p has an unexpected memattr", m));
2271 KASSERT((m->oflags & (VPO_SWAPINPROG |
2272 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2273 ("page %p has unexpected oflags", m));
2274 /* Don't care: VPO_NOSYNC. */
2279 VM_OBJECT_RUNLOCK(object);
2280 #if VM_NRESERVLEVEL > 0
2281 } else if (level >= 0) {
2283 * The page is reserved but not yet allocated. In
2284 * other words, it is still free. Extend the current
2289 } else if ((order = m->order) < VM_NFREEORDER) {
2291 * The page is enqueued in the physical memory
2292 * allocator's free page queues. Moreover, it is the
2293 * first page in a power-of-two-sized run of
2294 * contiguous free pages. Add these pages to the end
2295 * of the current run, and jump ahead.
2297 run_ext = 1 << order;
2301 * Skip the page for one of the following reasons: (1)
2302 * It is enqueued in the physical memory allocator's
2303 * free page queues. However, it is not the first
2304 * page in a run of contiguous free pages. (This case
2305 * rarely occurs because the scan is performed in
2306 * ascending order.) (2) It is not reserved, and it is
2307 * transitioning from free to allocated. (Conversely,
2308 * the transition from allocated to free for managed
2309 * pages is blocked by the page lock.) (3) It is
2310 * allocated but not contained by an object and not
2311 * wired, e.g., allocated by Xen's balloon driver.
2317 * Extend or reset the current run of pages.
2332 if (run_len >= npages)
2338 * vm_page_reclaim_run:
2340 * Try to relocate each of the allocated virtual pages within the
2341 * specified run of physical pages to a new physical address. Free the
2342 * physical pages underlying the relocated virtual pages. A virtual page
2343 * is relocatable if and only if it could be laundered or reclaimed by
2344 * the page daemon. Whenever possible, a virtual page is relocated to a
2345 * physical address above "high".
2347 * Returns 0 if every physical page within the run was already free or
2348 * just freed by a successful relocation. Otherwise, returns a non-zero
2349 * value indicating why the last attempt to relocate a virtual page was
2352 * "req_class" must be an allocation class.
2355 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run,
2358 struct vm_domain *vmd;
2360 struct spglist free;
2363 vm_page_t m, m_end, m_new;
2364 int error, order, req;
2366 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2367 ("req_class is not an allocation class"));
2371 m_end = m_run + npages;
2373 for (; error == 0 && m < m_end; m++) {
2374 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2375 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2378 * Avoid releasing and reacquiring the same page lock.
2380 vm_page_change_lock(m, &m_mtx);
2382 if (vm_page_held(m))
2384 else if ((object = m->object) != NULL) {
2386 * The page is relocated if and only if it could be
2387 * laundered or reclaimed by the page daemon.
2389 if (!VM_OBJECT_TRYWLOCK(object)) {
2391 VM_OBJECT_WLOCK(object);
2393 if (m->object != object) {
2395 * The page may have been freed.
2397 VM_OBJECT_WUNLOCK(object);
2399 } else if (vm_page_held(m)) {
2404 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2405 ("page %p is PG_UNHOLDFREE", m));
2406 /* Don't care: PG_NODUMP, PG_ZERO. */
2407 if (object->type != OBJT_DEFAULT &&
2408 object->type != OBJT_SWAP &&
2409 object->type != OBJT_VNODE)
2411 else if (object->memattr != VM_MEMATTR_DEFAULT)
2413 else if (m->queue != PQ_NONE && !vm_page_busied(m)) {
2414 KASSERT(pmap_page_get_memattr(m) ==
2416 ("page %p has an unexpected memattr", m));
2417 KASSERT((m->oflags & (VPO_SWAPINPROG |
2418 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2419 ("page %p has unexpected oflags", m));
2420 /* Don't care: VPO_NOSYNC. */
2421 if (m->valid != 0) {
2423 * First, try to allocate a new page
2424 * that is above "high". Failing
2425 * that, try to allocate a new page
2426 * that is below "m_run". Allocate
2427 * the new page between the end of
2428 * "m_run" and "high" only as a last
2431 req = req_class | VM_ALLOC_NOOBJ;
2432 if ((m->flags & PG_NODUMP) != 0)
2433 req |= VM_ALLOC_NODUMP;
2434 if (trunc_page(high) !=
2435 ~(vm_paddr_t)PAGE_MASK) {
2436 m_new = vm_page_alloc_contig(
2441 VM_MEMATTR_DEFAULT);
2444 if (m_new == NULL) {
2445 pa = VM_PAGE_TO_PHYS(m_run);
2446 m_new = vm_page_alloc_contig(
2448 0, pa - 1, PAGE_SIZE, 0,
2449 VM_MEMATTR_DEFAULT);
2451 if (m_new == NULL) {
2453 m_new = vm_page_alloc_contig(
2455 pa, high, PAGE_SIZE, 0,
2456 VM_MEMATTR_DEFAULT);
2458 if (m_new == NULL) {
2462 KASSERT(m_new->wire_count == 0,
2463 ("page %p is wired", m));
2466 * Replace "m" with the new page. For
2467 * vm_page_replace(), "m" must be busy
2468 * and dequeued. Finally, change "m"
2469 * as if vm_page_free() was called.
2471 if (object->ref_count != 0)
2473 m_new->aflags = m->aflags;
2474 KASSERT(m_new->oflags == VPO_UNMANAGED,
2475 ("page %p is managed", m));
2476 m_new->oflags = m->oflags & VPO_NOSYNC;
2477 pmap_copy_page(m, m_new);
2478 m_new->valid = m->valid;
2479 m_new->dirty = m->dirty;
2480 m->flags &= ~PG_ZERO;
2483 vm_page_replace_checked(m_new, object,
2489 * The new page must be deactivated
2490 * before the object is unlocked.
2492 vm_page_change_lock(m_new, &m_mtx);
2493 vm_page_deactivate(m_new);
2495 m->flags &= ~PG_ZERO;
2498 KASSERT(m->dirty == 0,
2499 ("page %p is dirty", m));
2501 SLIST_INSERT_HEAD(&free, m, plinks.s.ss);
2505 VM_OBJECT_WUNLOCK(object);
2507 MPASS(vm_phys_domain(m) == domain);
2508 vmd = VM_DOMAIN(domain);
2509 vm_domain_free_lock(vmd);
2511 if (order < VM_NFREEORDER) {
2513 * The page is enqueued in the physical memory
2514 * allocator's free page queues. Moreover, it
2515 * is the first page in a power-of-two-sized
2516 * run of contiguous free pages. Jump ahead
2517 * to the last page within that run, and
2518 * continue from there.
2520 m += (1 << order) - 1;
2522 #if VM_NRESERVLEVEL > 0
2523 else if (vm_reserv_is_page_free(m))
2526 vm_domain_free_unlock(vmd);
2527 if (order == VM_NFREEORDER)
2533 if ((m = SLIST_FIRST(&free)) != NULL) {
2536 vmd = VM_DOMAIN(domain);
2538 vm_domain_free_lock(vmd);
2540 MPASS(vm_phys_domain(m) == domain);
2541 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
2542 vm_page_free_phys(vmd, m);
2544 } while ((m = SLIST_FIRST(&free)) != NULL);
2545 vm_domain_free_unlock(vmd);
2546 vm_domain_freecnt_inc(vmd, cnt);
2553 CTASSERT(powerof2(NRUNS));
2555 #define RUN_INDEX(count) ((count) & (NRUNS - 1))
2557 #define MIN_RECLAIM 8
2560 * vm_page_reclaim_contig:
2562 * Reclaim allocated, contiguous physical memory satisfying the specified
2563 * conditions by relocating the virtual pages using that physical memory.
2564 * Returns true if reclamation is successful and false otherwise. Since
2565 * relocation requires the allocation of physical pages, reclamation may
2566 * fail due to a shortage of free pages. When reclamation fails, callers
2567 * are expected to perform vm_wait() before retrying a failed allocation
2568 * operation, e.g., vm_page_alloc_contig().
2570 * The caller must always specify an allocation class through "req".
2572 * allocation classes:
2573 * VM_ALLOC_NORMAL normal process request
2574 * VM_ALLOC_SYSTEM system *really* needs a page
2575 * VM_ALLOC_INTERRUPT interrupt time request
2577 * The optional allocation flags are ignored.
2579 * "npages" must be greater than zero. Both "alignment" and "boundary"
2580 * must be a power of two.
2583 vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
2584 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
2586 struct vm_domain *vmd;
2587 vm_paddr_t curr_low;
2588 vm_page_t m_run, m_runs[NRUNS];
2589 u_long count, reclaimed;
2590 int error, i, options, req_class;
2592 KASSERT(npages > 0, ("npages is 0"));
2593 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2594 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2595 req_class = req & VM_ALLOC_CLASS_MASK;
2598 * The page daemon is allowed to dig deeper into the free page list.
2600 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2601 req_class = VM_ALLOC_SYSTEM;
2604 * Return if the number of free pages cannot satisfy the requested
2607 vmd = VM_DOMAIN(domain);
2608 count = vmd->vmd_free_count;
2609 if (count < npages + vmd->vmd_free_reserved || (count < npages +
2610 vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
2611 (count < npages && req_class == VM_ALLOC_INTERRUPT))
2615 * Scan up to three times, relaxing the restrictions ("options") on
2616 * the reclamation of reservations and superpages each time.
2618 for (options = VPSC_NORESERV;;) {
2620 * Find the highest runs that satisfy the given constraints
2621 * and restrictions, and record them in "m_runs".
2626 m_run = vm_phys_scan_contig(domain, npages, curr_low,
2627 high, alignment, boundary, options);
2630 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages);
2631 m_runs[RUN_INDEX(count)] = m_run;
2636 * Reclaim the highest runs in LIFO (descending) order until
2637 * the number of reclaimed pages, "reclaimed", is at least
2638 * MIN_RECLAIM. Reset "reclaimed" each time because each
2639 * reclamation is idempotent, and runs will (likely) recur
2640 * from one scan to the next as restrictions are relaxed.
2643 for (i = 0; count > 0 && i < NRUNS; i++) {
2645 m_run = m_runs[RUN_INDEX(count)];
2646 error = vm_page_reclaim_run(req_class, domain, npages,
2649 reclaimed += npages;
2650 if (reclaimed >= MIN_RECLAIM)
2656 * Either relax the restrictions on the next scan or return if
2657 * the last scan had no restrictions.
2659 if (options == VPSC_NORESERV)
2660 options = VPSC_NOSUPER;
2661 else if (options == VPSC_NOSUPER)
2663 else if (options == VPSC_ANY)
2664 return (reclaimed != 0);
2669 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
2670 u_long alignment, vm_paddr_t boundary)
2672 struct vm_domainset_iter di;
2676 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req);
2678 ret = vm_page_reclaim_contig_domain(domain, req, npages, low,
2679 high, alignment, boundary);
2682 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
2688 * Set the domain in the appropriate page level domainset.
2691 vm_domain_set(struct vm_domain *vmd)
2694 mtx_lock(&vm_domainset_lock);
2695 if (!vmd->vmd_minset && vm_paging_min(vmd)) {
2696 vmd->vmd_minset = 1;
2697 DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains);
2699 if (!vmd->vmd_severeset && vm_paging_severe(vmd)) {
2700 vmd->vmd_severeset = 1;
2701 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains);
2703 mtx_unlock(&vm_domainset_lock);
2707 * Clear the domain from the appropriate page level domainset.
2710 vm_domain_clear(struct vm_domain *vmd)
2713 mtx_lock(&vm_domainset_lock);
2714 if (vmd->vmd_minset && !vm_paging_min(vmd)) {
2715 vmd->vmd_minset = 0;
2716 DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains);
2717 if (vm_min_waiters != 0) {
2719 wakeup(&vm_min_domains);
2722 if (vmd->vmd_severeset && !vm_paging_severe(vmd)) {
2723 vmd->vmd_severeset = 0;
2724 DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains);
2725 if (vm_severe_waiters != 0) {
2726 vm_severe_waiters = 0;
2727 wakeup(&vm_severe_domains);
2732 * If pageout daemon needs pages, then tell it that there are
2735 if (vmd->vmd_pageout_pages_needed &&
2736 vmd->vmd_free_count >= vmd->vmd_pageout_free_min) {
2737 wakeup(&vmd->vmd_pageout_pages_needed);
2738 vmd->vmd_pageout_pages_needed = 0;
2741 /* See comments in vm_wait_doms(). */
2742 if (vm_pageproc_waiters) {
2743 vm_pageproc_waiters = 0;
2744 wakeup(&vm_pageproc_waiters);
2746 mtx_unlock(&vm_domainset_lock);
2750 * Wait for free pages to exceed the min threshold globally.
2756 mtx_lock(&vm_domainset_lock);
2757 while (vm_page_count_min()) {
2759 msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0);
2761 mtx_unlock(&vm_domainset_lock);
2765 * Wait for free pages to exceed the severe threshold globally.
2768 vm_wait_severe(void)
2771 mtx_lock(&vm_domainset_lock);
2772 while (vm_page_count_severe()) {
2773 vm_severe_waiters++;
2774 msleep(&vm_severe_domains, &vm_domainset_lock, PVM,
2777 mtx_unlock(&vm_domainset_lock);
2784 return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters);
2788 vm_wait_doms(const domainset_t *wdoms)
2792 * We use racey wakeup synchronization to avoid expensive global
2793 * locking for the pageproc when sleeping with a non-specific vm_wait.
2794 * To handle this, we only sleep for one tick in this instance. It
2795 * is expected that most allocations for the pageproc will come from
2796 * kmem or vm_page_grab* which will use the more specific and
2797 * race-free vm_wait_domain().
2799 if (curproc == pageproc) {
2800 mtx_lock(&vm_domainset_lock);
2801 vm_pageproc_waiters++;
2802 msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP,
2806 * XXX Ideally we would wait only until the allocation could
2807 * be satisfied. This condition can cause new allocators to
2808 * consume all freed pages while old allocators wait.
2810 mtx_lock(&vm_domainset_lock);
2811 if (DOMAINSET_SUBSET(&vm_min_domains, wdoms)) {
2813 msleep(&vm_min_domains, &vm_domainset_lock, PVM,
2816 mtx_unlock(&vm_domainset_lock);
2823 * Sleep until free pages are available for allocation.
2824 * - Called in various places after failed memory allocations.
2827 vm_wait_domain(int domain)
2829 struct vm_domain *vmd;
2832 vmd = VM_DOMAIN(domain);
2833 vm_domain_free_assert_unlocked(vmd);
2835 if (curproc == pageproc) {
2836 mtx_lock(&vm_domainset_lock);
2837 if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) {
2838 vmd->vmd_pageout_pages_needed = 1;
2839 msleep(&vmd->vmd_pageout_pages_needed,
2840 &vm_domainset_lock, PDROP | PSWP, "VMWait", 0);
2842 mtx_unlock(&vm_domainset_lock);
2844 if (pageproc == NULL)
2845 panic("vm_wait in early boot");
2846 DOMAINSET_ZERO(&wdom);
2847 DOMAINSET_SET(vmd->vmd_domain, &wdom);
2848 vm_wait_doms(&wdom);
2855 * Sleep until free pages are available for allocation in the
2856 * affinity domains of the obj. If obj is NULL, the domain set
2857 * for the calling thread is used.
2858 * Called in various places after failed memory allocations.
2861 vm_wait(vm_object_t obj)
2863 struct domainset *d;
2868 * Carefully fetch pointers only once: the struct domainset
2869 * itself is ummutable but the pointer might change.
2872 d = obj->domain.dr_policy;
2874 d = curthread->td_domain.dr_policy;
2876 vm_wait_doms(&d->ds_mask);
2880 * vm_domain_alloc_fail:
2882 * Called when a page allocation function fails. Informs the
2883 * pagedaemon and performs the requested wait. Requires the
2884 * domain_free and object lock on entry. Returns with the
2885 * object lock held and free lock released. Returns an error when
2886 * retry is necessary.
2890 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req)
2893 vm_domain_free_assert_unlocked(vmd);
2895 atomic_add_int(&vmd->vmd_pageout_deficit,
2896 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
2897 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
2899 VM_OBJECT_WUNLOCK(object);
2900 vm_wait_domain(vmd->vmd_domain);
2902 VM_OBJECT_WLOCK(object);
2903 if (req & VM_ALLOC_WAITOK)
2913 * Sleep until free pages are available for allocation.
2914 * - Called only in vm_fault so that processes page faulting
2915 * can be easily tracked.
2916 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
2917 * processes will be able to grab memory first. Do not change
2918 * this balance without careful testing first.
2924 mtx_lock(&vm_domainset_lock);
2925 if (vm_page_count_min()) {
2927 msleep(&vm_min_domains, &vm_domainset_lock, PUSER, "pfault", 0);
2929 mtx_unlock(&vm_domainset_lock);
2932 struct vm_pagequeue *
2933 vm_page_pagequeue(vm_page_t m)
2936 return (&vm_pagequeue_domain(m)->vmd_pagequeues[m->queue]);
2942 * Remove the given page from its current page queue.
2944 * The page must be locked.
2947 vm_page_dequeue(vm_page_t m)
2949 struct vm_pagequeue *pq;
2951 vm_page_assert_locked(m);
2952 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued",
2954 pq = vm_page_pagequeue(m);
2955 vm_pagequeue_lock(pq);
2957 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2958 vm_pagequeue_cnt_dec(pq);
2959 vm_pagequeue_unlock(pq);
2963 * vm_page_dequeue_locked:
2965 * Remove the given page from its current page queue.
2967 * The page and page queue must be locked.
2970 vm_page_dequeue_locked(vm_page_t m)
2972 struct vm_pagequeue *pq;
2974 vm_page_lock_assert(m, MA_OWNED);
2975 pq = vm_page_pagequeue(m);
2976 vm_pagequeue_assert_locked(pq);
2978 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2979 vm_pagequeue_cnt_dec(pq);
2985 * Add the given page to the specified page queue.
2987 * The page must be locked.
2990 vm_page_enqueue(uint8_t queue, vm_page_t m)
2992 struct vm_pagequeue *pq;
2994 vm_page_lock_assert(m, MA_OWNED);
2995 KASSERT(queue < PQ_COUNT,
2996 ("vm_page_enqueue: invalid queue %u request for page %p",
2998 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue];
2999 vm_pagequeue_lock(pq);
3001 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3002 vm_pagequeue_cnt_inc(pq);
3003 vm_pagequeue_unlock(pq);
3009 * Move the given page to the tail of its current page queue.
3011 * The page must be locked.
3014 vm_page_requeue(vm_page_t m)
3016 struct vm_pagequeue *pq;
3018 vm_page_lock_assert(m, MA_OWNED);
3019 KASSERT(m->queue != PQ_NONE,
3020 ("vm_page_requeue: page %p is not queued", m));
3021 pq = vm_page_pagequeue(m);
3022 vm_pagequeue_lock(pq);
3023 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3024 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3025 vm_pagequeue_unlock(pq);
3029 * vm_page_requeue_locked:
3031 * Move the given page to the tail of its current page queue.
3033 * The page queue must be locked.
3036 vm_page_requeue_locked(vm_page_t m)
3038 struct vm_pagequeue *pq;
3040 KASSERT(m->queue != PQ_NONE,
3041 ("vm_page_requeue_locked: page %p is not queued", m));
3042 pq = vm_page_pagequeue(m);
3043 vm_pagequeue_assert_locked(pq);
3044 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3045 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3051 * Put the specified page on the active list (if appropriate).
3052 * Ensure that act_count is at least ACT_INIT but do not otherwise
3055 * The page must be locked.
3058 vm_page_activate(vm_page_t m)
3062 vm_page_lock_assert(m, MA_OWNED);
3063 if ((queue = m->queue) != PQ_ACTIVE) {
3064 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3065 if (m->act_count < ACT_INIT)
3066 m->act_count = ACT_INIT;
3067 if (queue != PQ_NONE)
3069 vm_page_enqueue(PQ_ACTIVE, m);
3072 if (m->act_count < ACT_INIT)
3073 m->act_count = ACT_INIT;
3078 * vm_page_free_prep:
3080 * Prepares the given page to be put on the free list,
3081 * disassociating it from any VM object. The caller may return
3082 * the page to the free list only if this function returns true.
3084 * The object must be locked. The page must be locked if it is
3085 * managed. For a queued managed page, the pagequeue_locked
3086 * argument specifies whether the page queue is already locked.
3089 vm_page_free_prep(vm_page_t m, bool pagequeue_locked)
3092 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
3093 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
3096 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
3097 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
3098 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
3099 m, i, (uintmax_t)*p));
3102 if ((m->oflags & VPO_UNMANAGED) == 0) {
3103 vm_page_lock_assert(m, MA_OWNED);
3104 KASSERT(!pmap_page_is_mapped(m),
3105 ("vm_page_free_toq: freeing mapped page %p", m));
3107 KASSERT(m->queue == PQ_NONE,
3108 ("vm_page_free_toq: unmanaged page %p is queued", m));
3109 VM_CNT_INC(v_tfree);
3111 if (vm_page_sbusied(m))
3112 panic("vm_page_free: freeing busy page %p", m);
3117 * If fictitious remove object association and
3120 if ((m->flags & PG_FICTITIOUS) != 0) {
3121 KASSERT(m->wire_count == 1,
3122 ("fictitious page %p is not wired", m));
3123 KASSERT(m->queue == PQ_NONE,
3124 ("fictitious page %p is queued", m));
3128 if (m->queue != PQ_NONE) {
3129 if (pagequeue_locked)
3130 vm_page_dequeue_locked(m);
3137 if (m->wire_count != 0)
3138 panic("vm_page_free: freeing wired page %p", m);
3139 if (m->hold_count != 0) {
3140 m->flags &= ~PG_ZERO;
3141 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
3142 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m));
3143 m->flags |= PG_UNHOLDFREE;
3148 * Restore the default memory attribute to the page.
3150 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
3151 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
3157 * Insert the page into the physical memory allocator's free page
3158 * queues. This is the last step to free a page. The caller is
3159 * responsible for adjusting the free page count.
3162 vm_page_free_phys(struct vm_domain *vmd, vm_page_t m)
3165 vm_domain_free_assert_locked(vmd);
3167 #if VM_NRESERVLEVEL > 0
3168 if (!vm_reserv_free_page(m))
3170 vm_phys_free_pages(m, 0);
3174 vm_page_free_phys_pglist(struct pglist *tq)
3176 struct vm_domain *vmd;
3180 if (TAILQ_EMPTY(tq))
3184 TAILQ_FOREACH(m, tq, listq) {
3185 if (vmd != vm_pagequeue_domain(m)) {
3187 vm_domain_free_unlock(vmd);
3188 vm_domain_freecnt_inc(vmd, cnt);
3191 vmd = vm_pagequeue_domain(m);
3192 vm_domain_free_lock(vmd);
3194 vm_page_free_phys(vmd, m);
3198 vm_domain_free_unlock(vmd);
3199 vm_domain_freecnt_inc(vmd, cnt);
3206 * Returns the given page to the free list, disassociating it
3207 * from any VM object.
3209 * The object must be locked. The page must be locked if it is
3213 vm_page_free_toq(vm_page_t m)
3215 struct vm_domain *vmd;
3217 if (!vm_page_free_prep(m, false))
3219 vmd = vm_pagequeue_domain(m);
3220 vm_domain_free_lock(vmd);
3221 vm_page_free_phys(vmd, m);
3222 vm_domain_free_unlock(vmd);
3223 vm_domain_freecnt_inc(vmd, 1);
3227 * vm_page_free_pages_toq:
3229 * Returns a list of pages to the free list, disassociating it
3230 * from any VM object. In other words, this is equivalent to
3231 * calling vm_page_free_toq() for each page of a list of VM objects.
3233 * The objects must be locked. The pages must be locked if it is
3237 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count)
3243 if (SLIST_EMPTY(free))
3248 while ((m = SLIST_FIRST(free)) != NULL) {
3250 SLIST_REMOVE_HEAD(free, plinks.s.ss);
3251 if (vm_page_free_prep(m, false))
3252 TAILQ_INSERT_TAIL(&pgl, m, listq);
3255 vm_page_free_phys_pglist(&pgl);
3257 if (update_wire_count)
3264 * Mark this page as wired down. If the page is fictitious, then
3265 * its wire count must remain one.
3267 * The page must be locked.
3270 vm_page_wire(vm_page_t m)
3273 vm_page_assert_locked(m);
3274 if ((m->flags & PG_FICTITIOUS) != 0) {
3275 KASSERT(m->wire_count == 1,
3276 ("vm_page_wire: fictitious page %p's wire count isn't one",
3280 if (m->wire_count == 0) {
3281 KASSERT((m->oflags & VPO_UNMANAGED) == 0 ||
3282 m->queue == PQ_NONE,
3283 ("vm_page_wire: unmanaged page %p is queued", m));
3287 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
3293 * Release one wiring of the specified page, potentially allowing it to be
3294 * paged out. Returns TRUE if the number of wirings transitions to zero and
3297 * Only managed pages belonging to an object can be paged out. If the number
3298 * of wirings transitions to zero and the page is eligible for page out, then
3299 * the page is added to the specified paging queue (unless PQ_NONE is
3300 * specified, in which case the page is dequeued if it belongs to a paging
3303 * If a page is fictitious, then its wire count must always be one.
3305 * A managed page must be locked.
3308 vm_page_unwire(vm_page_t m, uint8_t queue)
3312 KASSERT(queue < PQ_COUNT || queue == PQ_NONE,
3313 ("vm_page_unwire: invalid queue %u request for page %p",
3316 unwired = vm_page_unwire_noq(m);
3317 if (unwired && (m->oflags & VPO_UNMANAGED) == 0 && m->object != NULL) {
3318 if (m->queue == queue) {
3319 if (queue == PQ_ACTIVE)
3320 vm_page_reference(m);
3321 else if (queue != PQ_NONE)
3325 if (queue != PQ_NONE) {
3326 vm_page_enqueue(queue, m);
3327 if (queue == PQ_ACTIVE)
3328 /* Initialize act_count. */
3329 vm_page_activate(m);
3338 * vm_page_unwire_noq:
3340 * Unwire a page without (re-)inserting it into a page queue. It is up
3341 * to the caller to enqueue, requeue, or free the page as appropriate.
3342 * In most cases, vm_page_unwire() should be used instead.
3345 vm_page_unwire_noq(vm_page_t m)
3348 if ((m->oflags & VPO_UNMANAGED) == 0)
3349 vm_page_assert_locked(m);
3350 if ((m->flags & PG_FICTITIOUS) != 0) {
3351 KASSERT(m->wire_count == 1,
3352 ("vm_page_unwire: fictitious page %p's wire count isn't one", m));
3355 if (m->wire_count == 0)
3356 panic("vm_page_unwire: page %p's wire count is zero", m);
3358 if (m->wire_count == 0) {
3366 * Move the specified page to the inactive queue, or requeue the page if it is
3367 * already in the inactive queue.
3369 * Normally, "noreuse" is FALSE, resulting in LRU ordering of the inactive
3370 * queue. However, setting "noreuse" to TRUE will accelerate the specified
3371 * page's reclamation, but it will not unmap the page from any address space.
3372 * This is implemented by inserting the page near the head of the inactive
3373 * queue, using a marker page to guide FIFO insertion ordering.
3375 * The page must be locked.
3378 _vm_page_deactivate(vm_page_t m, boolean_t noreuse)
3380 struct vm_pagequeue *pq;
3383 vm_page_assert_locked(m);
3385 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3386 pq = &vm_pagequeue_domain(m)->vmd_pagequeues[PQ_INACTIVE];
3387 /* Avoid multiple acquisitions of the inactive queue lock. */
3389 if (queue == PQ_INACTIVE) {
3390 vm_pagequeue_lock(pq);
3391 vm_page_dequeue_locked(m);
3393 if (queue != PQ_NONE)
3395 vm_pagequeue_lock(pq);
3397 m->queue = PQ_INACTIVE;
3399 TAILQ_INSERT_BEFORE(
3400 &vm_pagequeue_domain(m)->vmd_inacthead, m,
3403 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3404 vm_pagequeue_cnt_inc(pq);
3405 vm_pagequeue_unlock(pq);
3410 * Move the specified page to the inactive queue, or requeue the page if it is
3411 * already in the inactive queue.
3413 * The page must be locked.
3416 vm_page_deactivate(vm_page_t m)
3419 _vm_page_deactivate(m, FALSE);
3423 * Move the specified page to the inactive queue with the expectation
3424 * that it is unlikely to be reused.
3426 * The page must be locked.
3429 vm_page_deactivate_noreuse(vm_page_t m)
3432 _vm_page_deactivate(m, TRUE);
3438 * Put a page in the laundry, or requeue it if it is already there.
3441 vm_page_launder(vm_page_t m)
3444 vm_page_assert_locked(m);
3445 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3446 if (m->queue == PQ_LAUNDRY)
3450 vm_page_enqueue(PQ_LAUNDRY, m);
3456 * vm_page_unswappable
3458 * Put a page in the PQ_UNSWAPPABLE holding queue.
3461 vm_page_unswappable(vm_page_t m)
3464 vm_page_assert_locked(m);
3465 KASSERT(m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0,
3466 ("page %p already unswappable", m));
3467 if (m->queue != PQ_NONE)
3469 vm_page_enqueue(PQ_UNSWAPPABLE, m);
3473 * Attempt to free the page. If it cannot be freed, do nothing. Returns true
3474 * if the page is freed and false otherwise.
3476 * The page must be managed. The page and its containing object must be
3480 vm_page_try_to_free(vm_page_t m)
3483 vm_page_assert_locked(m);
3484 VM_OBJECT_ASSERT_WLOCKED(m->object);
3485 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("page %p is unmanaged", m));
3486 if (m->dirty != 0 || vm_page_held(m) || vm_page_busied(m))
3488 if (m->object->ref_count != 0) {
3500 * Apply the specified advice to the given page.
3502 * The object and page must be locked.
3505 vm_page_advise(vm_page_t m, int advice)
3508 vm_page_assert_locked(m);
3509 VM_OBJECT_ASSERT_WLOCKED(m->object);
3510 if (advice == MADV_FREE)
3512 * Mark the page clean. This will allow the page to be freed
3513 * without first paging it out. MADV_FREE pages are often
3514 * quickly reused by malloc(3), so we do not do anything that
3515 * would result in a page fault on a later access.
3518 else if (advice != MADV_DONTNEED) {
3519 if (advice == MADV_WILLNEED)
3520 vm_page_activate(m);
3525 * Clear any references to the page. Otherwise, the page daemon will
3526 * immediately reactivate the page.
3528 vm_page_aflag_clear(m, PGA_REFERENCED);
3530 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
3534 * Place clean pages near the head of the inactive queue rather than
3535 * the tail, thus defeating the queue's LRU operation and ensuring that
3536 * the page will be reused quickly. Dirty pages not already in the
3537 * laundry are moved there.
3540 vm_page_deactivate_noreuse(m);
3541 else if (!vm_page_in_laundry(m))
3546 * Grab a page, waiting until we are waken up due to the page
3547 * changing state. We keep on waiting, if the page continues
3548 * to be in the object. If the page doesn't exist, first allocate it
3549 * and then conditionally zero it.
3551 * This routine may sleep.
3553 * The object must be locked on entry. The lock will, however, be released
3554 * and reacquired if the routine sleeps.
3557 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3563 VM_OBJECT_ASSERT_WLOCKED(object);
3564 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3565 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3566 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
3567 pflags = allocflags &
3568 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
3569 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
3570 pflags |= VM_ALLOC_WAITFAIL;
3572 if ((m = vm_page_lookup(object, pindex)) != NULL) {
3573 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3574 vm_page_xbusied(m) : vm_page_busied(m);
3576 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3579 * Reference the page before unlocking and
3580 * sleeping so that the page daemon is less
3581 * likely to reclaim it.
3583 vm_page_aflag_set(m, PGA_REFERENCED);
3585 VM_OBJECT_WUNLOCK(object);
3586 vm_page_busy_sleep(m, "pgrbwt", (allocflags &
3587 VM_ALLOC_IGN_SBUSY) != 0);
3588 VM_OBJECT_WLOCK(object);
3591 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3597 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
3599 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3604 m = vm_page_alloc(object, pindex, pflags);
3606 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3610 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
3616 * Return the specified range of pages from the given object. For each
3617 * page offset within the range, if a page already exists within the object
3618 * at that offset and it is busy, then wait for it to change state. If,
3619 * instead, the page doesn't exist, then allocate it.
3621 * The caller must always specify an allocation class.
3623 * allocation classes:
3624 * VM_ALLOC_NORMAL normal process request
3625 * VM_ALLOC_SYSTEM system *really* needs the pages
3627 * The caller must always specify that the pages are to be busied and/or
3630 * optional allocation flags:
3631 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages
3632 * VM_ALLOC_NOBUSY do not exclusive busy the page
3633 * VM_ALLOC_NOWAIT do not sleep
3634 * VM_ALLOC_SBUSY set page to sbusy state
3635 * VM_ALLOC_WIRED wire the pages
3636 * VM_ALLOC_ZERO zero and validate any invalid pages
3638 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it
3639 * may return a partial prefix of the requested range.
3642 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
3643 vm_page_t *ma, int count)
3650 VM_OBJECT_ASSERT_WLOCKED(object);
3651 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0,
3652 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed"));
3653 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
3654 (allocflags & VM_ALLOC_WIRED) != 0,
3655 ("vm_page_grab_pages: the pages must be busied or wired"));
3656 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3657 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3658 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch"));
3661 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK |
3662 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY);
3663 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
3664 pflags |= VM_ALLOC_WAITFAIL;
3667 m = vm_radix_lookup_le(&object->rtree, pindex + i);
3668 if (m == NULL || m->pindex != pindex + i) {
3672 mpred = TAILQ_PREV(m, pglist, listq);
3673 for (; i < count; i++) {
3675 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3676 vm_page_xbusied(m) : vm_page_busied(m);
3678 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3681 * Reference the page before unlocking and
3682 * sleeping so that the page daemon is less
3683 * likely to reclaim it.
3685 vm_page_aflag_set(m, PGA_REFERENCED);
3687 VM_OBJECT_WUNLOCK(object);
3688 vm_page_busy_sleep(m, "grbmaw", (allocflags &
3689 VM_ALLOC_IGN_SBUSY) != 0);
3690 VM_OBJECT_WLOCK(object);
3693 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3698 if ((allocflags & (VM_ALLOC_NOBUSY |
3699 VM_ALLOC_SBUSY)) == 0)
3701 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3704 m = vm_page_alloc_after(object, pindex + i,
3705 pflags | VM_ALLOC_COUNT(count - i), mpred);
3707 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3712 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) {
3713 if ((m->flags & PG_ZERO) == 0)
3715 m->valid = VM_PAGE_BITS_ALL;
3718 m = vm_page_next(m);
3724 * Mapping function for valid or dirty bits in a page.
3726 * Inputs are required to range within a page.
3729 vm_page_bits(int base, int size)
3735 base + size <= PAGE_SIZE,
3736 ("vm_page_bits: illegal base/size %d/%d", base, size)
3739 if (size == 0) /* handle degenerate case */
3742 first_bit = base >> DEV_BSHIFT;
3743 last_bit = (base + size - 1) >> DEV_BSHIFT;
3745 return (((vm_page_bits_t)2 << last_bit) -
3746 ((vm_page_bits_t)1 << first_bit));
3750 * vm_page_set_valid_range:
3752 * Sets portions of a page valid. The arguments are expected
3753 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3754 * of any partial chunks touched by the range. The invalid portion of
3755 * such chunks will be zeroed.
3757 * (base + size) must be less then or equal to PAGE_SIZE.
3760 vm_page_set_valid_range(vm_page_t m, int base, int size)
3764 VM_OBJECT_ASSERT_WLOCKED(m->object);
3765 if (size == 0) /* handle degenerate case */
3769 * If the base is not DEV_BSIZE aligned and the valid
3770 * bit is clear, we have to zero out a portion of the
3773 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3774 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
3775 pmap_zero_page_area(m, frag, base - frag);
3778 * If the ending offset is not DEV_BSIZE aligned and the
3779 * valid bit is clear, we have to zero out a portion of
3782 endoff = base + size;
3783 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3784 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
3785 pmap_zero_page_area(m, endoff,
3786 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3789 * Assert that no previously invalid block that is now being validated
3792 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
3793 ("vm_page_set_valid_range: page %p is dirty", m));
3796 * Set valid bits inclusive of any overlap.
3798 m->valid |= vm_page_bits(base, size);
3802 * Clear the given bits from the specified page's dirty field.
3804 static __inline void
3805 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
3808 #if PAGE_SIZE < 16384
3813 * If the object is locked and the page is neither exclusive busy nor
3814 * write mapped, then the page's dirty field cannot possibly be
3815 * set by a concurrent pmap operation.
3817 VM_OBJECT_ASSERT_WLOCKED(m->object);
3818 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
3819 m->dirty &= ~pagebits;
3822 * The pmap layer can call vm_page_dirty() without
3823 * holding a distinguished lock. The combination of
3824 * the object's lock and an atomic operation suffice
3825 * to guarantee consistency of the page dirty field.
3827 * For PAGE_SIZE == 32768 case, compiler already
3828 * properly aligns the dirty field, so no forcible
3829 * alignment is needed. Only require existence of
3830 * atomic_clear_64 when page size is 32768.
3832 addr = (uintptr_t)&m->dirty;
3833 #if PAGE_SIZE == 32768
3834 atomic_clear_64((uint64_t *)addr, pagebits);
3835 #elif PAGE_SIZE == 16384
3836 atomic_clear_32((uint32_t *)addr, pagebits);
3837 #else /* PAGE_SIZE <= 8192 */
3839 * Use a trick to perform a 32-bit atomic on the
3840 * containing aligned word, to not depend on the existence
3841 * of atomic_clear_{8, 16}.
3843 shift = addr & (sizeof(uint32_t) - 1);
3844 #if BYTE_ORDER == BIG_ENDIAN
3845 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
3849 addr &= ~(sizeof(uint32_t) - 1);
3850 atomic_clear_32((uint32_t *)addr, pagebits << shift);
3851 #endif /* PAGE_SIZE */
3856 * vm_page_set_validclean:
3858 * Sets portions of a page valid and clean. The arguments are expected
3859 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3860 * of any partial chunks touched by the range. The invalid portion of
3861 * such chunks will be zero'd.
3863 * (base + size) must be less then or equal to PAGE_SIZE.
3866 vm_page_set_validclean(vm_page_t m, int base, int size)
3868 vm_page_bits_t oldvalid, pagebits;
3871 VM_OBJECT_ASSERT_WLOCKED(m->object);
3872 if (size == 0) /* handle degenerate case */
3876 * If the base is not DEV_BSIZE aligned and the valid
3877 * bit is clear, we have to zero out a portion of the
3880 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3881 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
3882 pmap_zero_page_area(m, frag, base - frag);
3885 * If the ending offset is not DEV_BSIZE aligned and the
3886 * valid bit is clear, we have to zero out a portion of
3889 endoff = base + size;
3890 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3891 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
3892 pmap_zero_page_area(m, endoff,
3893 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3896 * Set valid, clear dirty bits. If validating the entire
3897 * page we can safely clear the pmap modify bit. We also
3898 * use this opportunity to clear the VPO_NOSYNC flag. If a process
3899 * takes a write fault on a MAP_NOSYNC memory area the flag will
3902 * We set valid bits inclusive of any overlap, but we can only
3903 * clear dirty bits for DEV_BSIZE chunks that are fully within
3906 oldvalid = m->valid;
3907 pagebits = vm_page_bits(base, size);
3908 m->valid |= pagebits;
3910 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
3911 frag = DEV_BSIZE - frag;
3917 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
3919 if (base == 0 && size == PAGE_SIZE) {
3921 * The page can only be modified within the pmap if it is
3922 * mapped, and it can only be mapped if it was previously
3925 if (oldvalid == VM_PAGE_BITS_ALL)
3927 * Perform the pmap_clear_modify() first. Otherwise,
3928 * a concurrent pmap operation, such as
3929 * pmap_protect(), could clear a modification in the
3930 * pmap and set the dirty field on the page before
3931 * pmap_clear_modify() had begun and after the dirty
3932 * field was cleared here.
3934 pmap_clear_modify(m);
3936 m->oflags &= ~VPO_NOSYNC;
3937 } else if (oldvalid != VM_PAGE_BITS_ALL)
3938 m->dirty &= ~pagebits;
3940 vm_page_clear_dirty_mask(m, pagebits);
3944 vm_page_clear_dirty(vm_page_t m, int base, int size)
3947 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
3951 * vm_page_set_invalid:
3953 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3954 * valid and dirty bits for the effected areas are cleared.
3957 vm_page_set_invalid(vm_page_t m, int base, int size)
3959 vm_page_bits_t bits;
3963 VM_OBJECT_ASSERT_WLOCKED(object);
3964 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
3965 size >= object->un_pager.vnp.vnp_size)
3966 bits = VM_PAGE_BITS_ALL;
3968 bits = vm_page_bits(base, size);
3969 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL &&
3972 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
3973 !pmap_page_is_mapped(m),
3974 ("vm_page_set_invalid: page %p is mapped", m));
3980 * vm_page_zero_invalid()
3982 * The kernel assumes that the invalid portions of a page contain
3983 * garbage, but such pages can be mapped into memory by user code.
3984 * When this occurs, we must zero out the non-valid portions of the
3985 * page so user code sees what it expects.
3987 * Pages are most often semi-valid when the end of a file is mapped
3988 * into memory and the file's size is not page aligned.
3991 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3996 VM_OBJECT_ASSERT_WLOCKED(m->object);
3998 * Scan the valid bits looking for invalid sections that
3999 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
4000 * valid bit may be set ) have already been zeroed by
4001 * vm_page_set_validclean().
4003 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
4004 if (i == (PAGE_SIZE / DEV_BSIZE) ||
4005 (m->valid & ((vm_page_bits_t)1 << i))) {
4007 pmap_zero_page_area(m,
4008 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
4015 * setvalid is TRUE when we can safely set the zero'd areas
4016 * as being valid. We can do this if there are no cache consistancy
4017 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
4020 m->valid = VM_PAGE_BITS_ALL;
4026 * Is (partial) page valid? Note that the case where size == 0
4027 * will return FALSE in the degenerate case where the page is
4028 * entirely invalid, and TRUE otherwise.
4031 vm_page_is_valid(vm_page_t m, int base, int size)
4033 vm_page_bits_t bits;
4035 VM_OBJECT_ASSERT_LOCKED(m->object);
4036 bits = vm_page_bits(base, size);
4037 return (m->valid != 0 && (m->valid & bits) == bits);
4041 * Returns true if all of the specified predicates are true for the entire
4042 * (super)page and false otherwise.
4045 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m)
4051 VM_OBJECT_ASSERT_LOCKED(object);
4052 npages = atop(pagesizes[m->psind]);
4055 * The physically contiguous pages that make up a superpage, i.e., a
4056 * page with a page size index ("psind") greater than zero, will
4057 * occupy adjacent entries in vm_page_array[].
4059 for (i = 0; i < npages; i++) {
4060 /* Always test object consistency, including "skip_m". */
4061 if (m[i].object != object)
4063 if (&m[i] == skip_m)
4065 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i]))
4067 if ((flags & PS_ALL_DIRTY) != 0) {
4069 * Calling vm_page_test_dirty() or pmap_is_modified()
4070 * might stop this case from spuriously returning
4071 * "false". However, that would require a write lock
4072 * on the object containing "m[i]".
4074 if (m[i].dirty != VM_PAGE_BITS_ALL)
4077 if ((flags & PS_ALL_VALID) != 0 &&
4078 m[i].valid != VM_PAGE_BITS_ALL)
4085 * Set the page's dirty bits if the page is modified.
4088 vm_page_test_dirty(vm_page_t m)
4091 VM_OBJECT_ASSERT_WLOCKED(m->object);
4092 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
4097 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
4100 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
4104 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
4107 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
4111 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
4114 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
4117 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
4119 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
4122 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
4126 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
4129 mtx_assert_(vm_page_lockptr(m), a, file, line);
4135 vm_page_object_lock_assert(vm_page_t m)
4139 * Certain of the page's fields may only be modified by the
4140 * holder of the containing object's lock or the exclusive busy.
4141 * holder. Unfortunately, the holder of the write busy is
4142 * not recorded, and thus cannot be checked here.
4144 if (m->object != NULL && !vm_page_xbusied(m))
4145 VM_OBJECT_ASSERT_WLOCKED(m->object);
4149 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits)
4152 if ((bits & PGA_WRITEABLE) == 0)
4156 * The PGA_WRITEABLE flag can only be set if the page is
4157 * managed, is exclusively busied or the object is locked.
4158 * Currently, this flag is only set by pmap_enter().
4160 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4161 ("PGA_WRITEABLE on unmanaged page"));
4162 if (!vm_page_xbusied(m))
4163 VM_OBJECT_ASSERT_LOCKED(m->object);
4167 #include "opt_ddb.h"
4169 #include <sys/kernel.h>
4171 #include <ddb/ddb.h>
4173 DB_SHOW_COMMAND(page, vm_page_print_page_info)
4176 db_printf("vm_cnt.v_free_count: %d\n", vm_free_count());
4177 db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count());
4178 db_printf("vm_cnt.v_active_count: %d\n", vm_active_count());
4179 db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count());
4180 db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count());
4181 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
4182 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
4183 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
4184 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
4187 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
4191 db_printf("pq_free %d\n", vm_free_count());
4192 for (dom = 0; dom < vm_ndomains; dom++) {
4194 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
4196 vm_dom[dom].vmd_page_count,
4197 vm_dom[dom].vmd_free_count,
4198 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
4199 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
4200 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
4201 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
4205 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
4211 db_printf("show pginfo addr\n");
4215 phys = strchr(modif, 'p') != NULL;
4217 m = PHYS_TO_VM_PAGE(addr);
4219 m = (vm_page_t)addr;
4221 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n"
4222 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
4223 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
4224 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags,
4225 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);