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_object.h>
116 #include <vm/vm_page.h>
117 #include <vm/vm_pageout.h>
118 #include <vm/vm_pager.h>
119 #include <vm/vm_phys.h>
120 #include <vm/vm_radix.h>
121 #include <vm/vm_reserv.h>
122 #include <vm/vm_extern.h>
124 #include <vm/uma_int.h>
126 #include <machine/md_var.h>
128 extern int uma_startup_count(int);
129 extern void uma_startup(void *, int);
130 extern void uma_startup1(void);
133 * Associated with page of user-allocatable memory is a
137 struct vm_domain vm_dom[MAXMEMDOM];
138 struct mtx_padalign __exclusive_cache_line vm_page_queue_free_mtx;
140 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT];
143 * bogus page -- for I/O to/from partially complete buffers,
144 * or for paging into sparsely invalid regions.
146 vm_page_t bogus_page;
148 vm_page_t vm_page_array;
149 long vm_page_array_size;
152 static int boot_pages;
153 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
155 "number of pages allocated for bootstrapping the VM system");
157 static int pa_tryrelock_restart;
158 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
159 &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
161 static TAILQ_HEAD(, vm_page) blacklist_head;
162 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
163 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
164 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
166 /* Is the page daemon waiting for free pages? */
167 static int vm_pageout_pages_needed;
169 static uma_zone_t fakepg_zone;
171 static void vm_page_alloc_check(vm_page_t m);
172 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
173 static void vm_page_enqueue(uint8_t queue, vm_page_t m);
174 static void vm_page_free_phys(vm_page_t m);
175 static void vm_page_free_wakeup(void);
176 static void vm_page_init(void *dummy);
177 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
178 vm_pindex_t pindex, vm_page_t mpred);
179 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
181 static int vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
183 static int vm_page_alloc_fail(vm_object_t object, int req);
185 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL);
188 vm_page_init(void *dummy)
191 fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
192 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
193 bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ |
194 VM_ALLOC_NORMAL | VM_ALLOC_WIRED);
197 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
198 #if PAGE_SIZE == 32768
200 CTASSERT(sizeof(u_long) >= 8);
205 * Try to acquire a physical address lock while a pmap is locked. If we
206 * fail to trylock we unlock and lock the pmap directly and cache the
207 * locked pa in *locked. The caller should then restart their loop in case
208 * the virtual to physical mapping has changed.
211 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
218 PA_LOCK_ASSERT(lockpa, MA_OWNED);
219 if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
226 atomic_add_int(&pa_tryrelock_restart, 1);
235 * Sets the page size, perhaps based upon the memory
236 * size. Must be called before any use of page-size
237 * dependent functions.
240 vm_set_page_size(void)
242 if (vm_cnt.v_page_size == 0)
243 vm_cnt.v_page_size = PAGE_SIZE;
244 if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
245 panic("vm_set_page_size: page size not a power of two");
249 * vm_page_blacklist_next:
251 * Find the next entry in the provided string of blacklist
252 * addresses. Entries are separated by space, comma, or newline.
253 * If an invalid integer is encountered then the rest of the
254 * string is skipped. Updates the list pointer to the next
255 * character, or NULL if the string is exhausted or invalid.
258 vm_page_blacklist_next(char **list, char *end)
263 if (list == NULL || *list == NULL)
271 * If there's no end pointer then the buffer is coming from
272 * the kenv and we know it's null-terminated.
275 end = *list + strlen(*list);
277 /* Ensure that strtoq() won't walk off the end */
279 if (*end == '\n' || *end == ' ' || *end == ',')
282 printf("Blacklist not terminated, skipping\n");
288 for (pos = *list; *pos != '\0'; pos = cp) {
289 bad = strtoq(pos, &cp, 0);
290 if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
299 if (*cp == '\0' || ++cp >= end)
303 return (trunc_page(bad));
305 printf("Garbage in RAM blacklist, skipping\n");
311 * vm_page_blacklist_check:
313 * Iterate through the provided string of blacklist addresses, pulling
314 * each entry out of the physical allocator free list and putting it
315 * onto a list for reporting via the vm.page_blacklist sysctl.
318 vm_page_blacklist_check(char *list, char *end)
326 while (next != NULL) {
327 if ((pa = vm_page_blacklist_next(&next, end)) == 0)
329 m = vm_phys_paddr_to_vm_page(pa);
332 mtx_lock(&vm_page_queue_free_mtx);
333 ret = vm_phys_unfree_page(m);
334 mtx_unlock(&vm_page_queue_free_mtx);
336 TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
338 printf("Skipping page with pa 0x%jx\n",
345 * vm_page_blacklist_load:
347 * Search for a special module named "ram_blacklist". It'll be a
348 * plain text file provided by the user via the loader directive
352 vm_page_blacklist_load(char **list, char **end)
361 mod = preload_search_by_type("ram_blacklist");
363 ptr = preload_fetch_addr(mod);
364 len = preload_fetch_size(mod);
375 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
382 error = sysctl_wire_old_buffer(req, 0);
385 sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
386 TAILQ_FOREACH(m, &blacklist_head, listq) {
387 sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
388 (uintmax_t)m->phys_addr);
391 error = sbuf_finish(&sbuf);
397 vm_page_domain_init(struct vm_domain *vmd)
399 struct vm_pagequeue *pq;
402 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
403 "vm inactive pagequeue";
404 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_vcnt) =
405 &vm_cnt.v_inactive_count;
406 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
407 "vm active pagequeue";
408 *__DECONST(u_int **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_vcnt) =
409 &vm_cnt.v_active_count;
410 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) =
411 "vm laundry pagequeue";
412 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_vcnt) =
413 &vm_cnt.v_laundry_count;
414 *__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) =
415 "vm unswappable pagequeue";
416 /* Unswappable dirty pages are counted as being in the laundry. */
417 *__DECONST(int **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_vcnt) =
418 &vm_cnt.v_laundry_count;
419 vmd->vmd_page_count = 0;
420 vmd->vmd_free_count = 0;
422 vmd->vmd_oom = FALSE;
423 for (i = 0; i < PQ_COUNT; i++) {
424 pq = &vmd->vmd_pagequeues[i];
425 TAILQ_INIT(&pq->pq_pl);
426 mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
427 MTX_DEF | MTX_DUPOK);
432 * Initialize a physical page in preparation for adding it to the free
436 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind)
441 m->busy_lock = VPB_UNBUSIED;
448 m->order = VM_NFREEORDER;
449 m->pool = VM_FREEPOOL_DEFAULT;
450 m->valid = m->dirty = 0;
457 * Initializes the resident memory module. Allocates physical memory for
458 * bootstrapping UMA and some data structures that are used to manage
459 * physical pages. Initializes these structures, and populates the free
463 vm_page_startup(vm_offset_t vaddr)
465 struct vm_domain *vmd;
466 struct vm_phys_seg *seg;
468 char *list, *listend;
470 vm_paddr_t end, high_avail, low_avail, new_end, page_range, size;
471 vm_paddr_t biggestsize, last_pa, pa;
473 int biggestone, i, segind;
477 vaddr = round_page(vaddr);
479 for (i = 0; phys_avail[i + 1]; i += 2) {
480 phys_avail[i] = round_page(phys_avail[i]);
481 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
483 for (i = 0; phys_avail[i + 1]; i += 2) {
484 size = phys_avail[i + 1] - phys_avail[i];
485 if (size > biggestsize) {
491 end = phys_avail[biggestone+1];
494 * Initialize the page and queue locks.
496 mtx_init(&vm_page_queue_free_mtx, "vm page free queue", NULL, MTX_DEF);
497 for (i = 0; i < PA_LOCK_COUNT; i++)
498 mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
499 for (i = 0; i < vm_ndomains; i++)
500 vm_page_domain_init(&vm_dom[i]);
503 * Allocate memory for use when boot strapping the kernel memory
506 * CTFLAG_RDTUN doesn't work during the early boot process, so we must
507 * manually fetch the value.
509 boot_pages = uma_startup_count(0);
510 TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages);
511 new_end = end - (boot_pages * UMA_SLAB_SIZE);
512 new_end = trunc_page(new_end);
513 mapped = pmap_map(&vaddr, new_end, end,
514 VM_PROT_READ | VM_PROT_WRITE);
515 bzero((void *)mapped, end - new_end);
516 uma_startup((void *)mapped, boot_pages);
518 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
519 defined(__i386__) || defined(__mips__)
521 * Allocate a bitmap to indicate that a random physical page
522 * needs to be included in a minidump.
524 * The amd64 port needs this to indicate which direct map pages
525 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
527 * However, i386 still needs this workspace internally within the
528 * minidump code. In theory, they are not needed on i386, but are
529 * included should the sf_buf code decide to use them.
532 for (i = 0; dump_avail[i + 1] != 0; i += 2)
533 if (dump_avail[i + 1] > last_pa)
534 last_pa = dump_avail[i + 1];
535 page_range = last_pa / PAGE_SIZE;
536 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
537 new_end -= vm_page_dump_size;
538 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
539 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
540 bzero((void *)vm_page_dump, vm_page_dump_size);
544 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
546 * Include the UMA bootstrap pages and vm_page_dump in a crash dump.
547 * When pmap_map() uses the direct map, they are not automatically
550 for (pa = new_end; pa < end; pa += PAGE_SIZE)
553 phys_avail[biggestone + 1] = new_end;
556 * Request that the physical pages underlying the message buffer be
557 * included in a crash dump. Since the message buffer is accessed
558 * through the direct map, they are not automatically included.
560 pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
561 last_pa = pa + round_page(msgbufsize);
562 while (pa < last_pa) {
568 * Compute the number of pages of memory that will be available for
569 * use, taking into account the overhead of a page structure per page.
570 * In other words, solve
571 * "available physical memory" - round_page(page_range *
572 * sizeof(struct vm_page)) = page_range * PAGE_SIZE
575 low_avail = phys_avail[0];
576 high_avail = phys_avail[1];
577 for (i = 0; i < vm_phys_nsegs; i++) {
578 if (vm_phys_segs[i].start < low_avail)
579 low_avail = vm_phys_segs[i].start;
580 if (vm_phys_segs[i].end > high_avail)
581 high_avail = vm_phys_segs[i].end;
583 /* Skip the first chunk. It is already accounted for. */
584 for (i = 2; phys_avail[i + 1] != 0; i += 2) {
585 if (phys_avail[i] < low_avail)
586 low_avail = phys_avail[i];
587 if (phys_avail[i + 1] > high_avail)
588 high_avail = phys_avail[i + 1];
590 first_page = low_avail / PAGE_SIZE;
591 #ifdef VM_PHYSSEG_SPARSE
593 for (i = 0; i < vm_phys_nsegs; i++)
594 size += vm_phys_segs[i].end - vm_phys_segs[i].start;
595 for (i = 0; phys_avail[i + 1] != 0; i += 2)
596 size += phys_avail[i + 1] - phys_avail[i];
597 #elif defined(VM_PHYSSEG_DENSE)
598 size = high_avail - low_avail;
600 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
603 #ifdef VM_PHYSSEG_DENSE
605 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
606 * the overhead of a page structure per page only if vm_page_array is
607 * allocated from the last physical memory chunk. Otherwise, we must
608 * allocate page structures representing the physical memory
609 * underlying vm_page_array, even though they will not be used.
611 if (new_end != high_avail)
612 page_range = size / PAGE_SIZE;
616 page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
619 * If the partial bytes remaining are large enough for
620 * a page (PAGE_SIZE) without a corresponding
621 * 'struct vm_page', then new_end will contain an
622 * extra page after subtracting the length of the VM
623 * page array. Compensate by subtracting an extra
626 if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
627 if (new_end == high_avail)
628 high_avail -= PAGE_SIZE;
629 new_end -= PAGE_SIZE;
635 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
636 * However, because this page is allocated from KVM, out-of-bounds
637 * accesses using the direct map will not be trapped.
642 * Allocate physical memory for the page structures, and map it.
644 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
645 mapped = pmap_map(&vaddr, new_end, end,
646 VM_PROT_READ | VM_PROT_WRITE);
647 vm_page_array = (vm_page_t)mapped;
648 vm_page_array_size = page_range;
650 #if VM_NRESERVLEVEL > 0
652 * Allocate physical memory for the reservation management system's
653 * data structures, and map it.
655 if (high_avail == end)
656 high_avail = new_end;
657 new_end = vm_reserv_startup(&vaddr, new_end, high_avail);
659 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__)
661 * Include vm_page_array and vm_reserv_array in a crash dump.
663 for (pa = new_end; pa < end; pa += PAGE_SIZE)
666 phys_avail[biggestone + 1] = new_end;
669 * Add physical memory segments corresponding to the available
672 for (i = 0; phys_avail[i + 1] != 0; i += 2)
673 vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
676 * Initialize the physical memory allocator.
681 * Initialize the page structures and add every available page to the
682 * physical memory allocator's free lists.
684 vm_cnt.v_page_count = 0;
685 vm_cnt.v_free_count = 0;
686 for (segind = 0; segind < vm_phys_nsegs; segind++) {
687 seg = &vm_phys_segs[segind];
688 for (m = seg->first_page, pa = seg->start; pa < seg->end;
689 m++, pa += PAGE_SIZE)
690 vm_page_init_page(m, pa, segind);
693 * Add the segment to the free lists only if it is covered by
694 * one of the ranges in phys_avail. Because we've added the
695 * ranges to the vm_phys_segs array, we can assume that each
696 * segment is either entirely contained in one of the ranges,
697 * or doesn't overlap any of them.
699 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
700 if (seg->start < phys_avail[i] ||
701 seg->end > phys_avail[i + 1])
705 pagecount = (u_long)atop(seg->end - seg->start);
707 mtx_lock(&vm_page_queue_free_mtx);
708 vm_phys_free_contig(m, pagecount);
709 vm_phys_freecnt_adj(m, (int)pagecount);
710 mtx_unlock(&vm_page_queue_free_mtx);
711 vm_cnt.v_page_count += (u_int)pagecount;
713 vmd = &vm_dom[seg->domain];
714 vmd->vmd_page_count += (u_int)pagecount;
715 vmd->vmd_segs |= 1UL << m->segind;
721 * Remove blacklisted pages from the physical memory allocator.
723 TAILQ_INIT(&blacklist_head);
724 vm_page_blacklist_load(&list, &listend);
725 vm_page_blacklist_check(list, listend);
727 list = kern_getenv("vm.blacklist");
728 vm_page_blacklist_check(list, NULL);
731 #if VM_NRESERVLEVEL > 0
733 * Initialize the reservation management system.
738 * Set an initial domain policy for thread0 so that allocations
743 /* Announce page availability to UMA. */
750 vm_page_reference(vm_page_t m)
753 vm_page_aflag_set(m, PGA_REFERENCED);
757 * vm_page_busy_downgrade:
759 * Downgrade an exclusive busy page into a single shared busy page.
762 vm_page_busy_downgrade(vm_page_t m)
767 vm_page_assert_xbusied(m);
768 locked = mtx_owned(vm_page_lockptr(m));
772 x &= VPB_BIT_WAITERS;
773 if (x != 0 && !locked)
775 if (atomic_cmpset_rel_int(&m->busy_lock,
776 VPB_SINGLE_EXCLUSIVER | x, VPB_SHARERS_WORD(1)))
778 if (x != 0 && !locked)
791 * Return a positive value if the page is shared busied, 0 otherwise.
794 vm_page_sbusied(vm_page_t m)
799 return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
805 * Shared unbusy a page.
808 vm_page_sunbusy(vm_page_t m)
812 vm_page_lock_assert(m, MA_NOTOWNED);
813 vm_page_assert_sbusied(m);
817 if (VPB_SHARERS(x) > 1) {
818 if (atomic_cmpset_int(&m->busy_lock, x,
823 if ((x & VPB_BIT_WAITERS) == 0) {
824 KASSERT(x == VPB_SHARERS_WORD(1),
825 ("vm_page_sunbusy: invalid lock state"));
826 if (atomic_cmpset_int(&m->busy_lock,
827 VPB_SHARERS_WORD(1), VPB_UNBUSIED))
831 KASSERT(x == (VPB_SHARERS_WORD(1) | VPB_BIT_WAITERS),
832 ("vm_page_sunbusy: invalid lock state for waiters"));
835 if (!atomic_cmpset_int(&m->busy_lock, x, VPB_UNBUSIED)) {
846 * vm_page_busy_sleep:
848 * Sleep and release the page lock, using the page pointer as wchan.
849 * This is used to implement the hard-path of busying mechanism.
851 * The given page must be locked.
853 * If nonshared is true, sleep only if the page is xbusy.
856 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared)
860 vm_page_assert_locked(m);
863 if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) ||
864 ((x & VPB_BIT_WAITERS) == 0 &&
865 !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) {
869 msleep(m, vm_page_lockptr(m), PVM | PDROP, wmesg, 0);
875 * Try to shared busy a page.
876 * If the operation succeeds 1 is returned otherwise 0.
877 * The operation never sleeps.
880 vm_page_trysbusy(vm_page_t m)
886 if ((x & VPB_BIT_SHARED) == 0)
888 if (atomic_cmpset_acq_int(&m->busy_lock, x, x + VPB_ONE_SHARER))
894 vm_page_xunbusy_locked(vm_page_t m)
897 vm_page_assert_xbusied(m);
898 vm_page_assert_locked(m);
900 atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
901 /* There is a waiter, do wakeup() instead of vm_page_flash(). */
906 vm_page_xunbusy_maybelocked(vm_page_t m)
910 vm_page_assert_xbusied(m);
913 * Fast path for unbusy. If it succeeds, we know that there
914 * are no waiters, so we do not need a wakeup.
916 if (atomic_cmpset_rel_int(&m->busy_lock, VPB_SINGLE_EXCLUSIVER,
920 lockacq = !mtx_owned(vm_page_lockptr(m));
923 vm_page_xunbusy_locked(m);
929 * vm_page_xunbusy_hard:
931 * Called after the first try the exclusive unbusy of a page failed.
932 * It is assumed that the waiters bit is on.
935 vm_page_xunbusy_hard(vm_page_t m)
938 vm_page_assert_xbusied(m);
941 vm_page_xunbusy_locked(m);
948 * Wakeup anyone waiting for the page.
949 * The ownership bits do not change.
951 * The given page must be locked.
954 vm_page_flash(vm_page_t m)
958 vm_page_lock_assert(m, MA_OWNED);
962 if ((x & VPB_BIT_WAITERS) == 0)
964 if (atomic_cmpset_int(&m->busy_lock, x,
965 x & (~VPB_BIT_WAITERS)))
972 * Avoid releasing and reacquiring the same page lock.
975 vm_page_change_lock(vm_page_t m, struct mtx **mtx)
979 mtx1 = vm_page_lockptr(m);
989 * Keep page from being freed by the page daemon
990 * much of the same effect as wiring, except much lower
991 * overhead and should be used only for *very* temporary
992 * holding ("wiring").
995 vm_page_hold(vm_page_t mem)
998 vm_page_lock_assert(mem, MA_OWNED);
1003 vm_page_unhold(vm_page_t mem)
1006 vm_page_lock_assert(mem, MA_OWNED);
1007 KASSERT(mem->hold_count >= 1, ("vm_page_unhold: hold count < 0!!!"));
1009 if (mem->hold_count == 0 && (mem->flags & PG_UNHOLDFREE) != 0)
1010 vm_page_free_toq(mem);
1014 * vm_page_unhold_pages:
1016 * Unhold each of the pages that is referenced by the given array.
1019 vm_page_unhold_pages(vm_page_t *ma, int count)
1024 for (; count != 0; count--) {
1025 vm_page_change_lock(*ma, &mtx);
1026 vm_page_unhold(*ma);
1034 PHYS_TO_VM_PAGE(vm_paddr_t pa)
1038 #ifdef VM_PHYSSEG_SPARSE
1039 m = vm_phys_paddr_to_vm_page(pa);
1041 m = vm_phys_fictitious_to_vm_page(pa);
1043 #elif defined(VM_PHYSSEG_DENSE)
1047 if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1048 m = &vm_page_array[pi - first_page];
1051 return (vm_phys_fictitious_to_vm_page(pa));
1053 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
1060 * Create a fictitious page with the specified physical address and
1061 * memory attribute. The memory attribute is the only the machine-
1062 * dependent aspect of a fictitious page that must be initialized.
1065 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1069 m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1070 vm_page_initfake(m, paddr, memattr);
1075 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1078 if ((m->flags & PG_FICTITIOUS) != 0) {
1080 * The page's memattr might have changed since the
1081 * previous initialization. Update the pmap to the
1086 m->phys_addr = paddr;
1088 /* Fictitious pages don't use "segind". */
1089 m->flags = PG_FICTITIOUS;
1090 /* Fictitious pages don't use "order" or "pool". */
1091 m->oflags = VPO_UNMANAGED;
1092 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1096 pmap_page_set_memattr(m, memattr);
1102 * Release a fictitious page.
1105 vm_page_putfake(vm_page_t m)
1108 KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1109 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1110 ("vm_page_putfake: bad page %p", m));
1111 uma_zfree(fakepg_zone, m);
1115 * vm_page_updatefake:
1117 * Update the given fictitious page to the specified physical address and
1121 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1124 KASSERT((m->flags & PG_FICTITIOUS) != 0,
1125 ("vm_page_updatefake: bad page %p", m));
1126 m->phys_addr = paddr;
1127 pmap_page_set_memattr(m, memattr);
1136 vm_page_free(vm_page_t m)
1139 m->flags &= ~PG_ZERO;
1140 vm_page_free_toq(m);
1144 * vm_page_free_zero:
1146 * Free a page to the zerod-pages queue
1149 vm_page_free_zero(vm_page_t m)
1152 m->flags |= PG_ZERO;
1153 vm_page_free_toq(m);
1157 * Unbusy and handle the page queueing for a page from a getpages request that
1158 * was optionally read ahead or behind.
1161 vm_page_readahead_finish(vm_page_t m)
1164 /* We shouldn't put invalid pages on queues. */
1165 KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
1168 * Since the page is not the actually needed one, whether it should
1169 * be activated or deactivated is not obvious. Empirical results
1170 * have shown that deactivating the page is usually the best choice,
1171 * unless the page is wanted by another thread.
1174 if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
1175 vm_page_activate(m);
1177 vm_page_deactivate(m);
1183 * vm_page_sleep_if_busy:
1185 * Sleep and release the page queues lock if the page is busied.
1186 * Returns TRUE if the thread slept.
1188 * The given page must be unlocked and object containing it must
1192 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
1196 vm_page_lock_assert(m, MA_NOTOWNED);
1197 VM_OBJECT_ASSERT_WLOCKED(m->object);
1199 if (vm_page_busied(m)) {
1201 * The page-specific object must be cached because page
1202 * identity can change during the sleep, causing the
1203 * re-lock of a different object.
1204 * It is assumed that a reference to the object is already
1205 * held by the callers.
1209 VM_OBJECT_WUNLOCK(obj);
1210 vm_page_busy_sleep(m, msg, false);
1211 VM_OBJECT_WLOCK(obj);
1218 * vm_page_dirty_KBI: [ internal use only ]
1220 * Set all bits in the page's dirty field.
1222 * The object containing the specified page must be locked if the
1223 * call is made from the machine-independent layer.
1225 * See vm_page_clear_dirty_mask().
1227 * This function should only be called by vm_page_dirty().
1230 vm_page_dirty_KBI(vm_page_t m)
1233 /* Refer to this operation by its public name. */
1234 KASSERT(m->valid == VM_PAGE_BITS_ALL,
1235 ("vm_page_dirty: page is invalid!"));
1236 m->dirty = VM_PAGE_BITS_ALL;
1240 * vm_page_insert: [ internal use only ]
1242 * Inserts the given mem entry into the object and object list.
1244 * The object must be locked.
1247 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1251 VM_OBJECT_ASSERT_WLOCKED(object);
1252 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1253 return (vm_page_insert_after(m, object, pindex, mpred));
1257 * vm_page_insert_after:
1259 * Inserts the page "m" into the specified object at offset "pindex".
1261 * The page "mpred" must immediately precede the offset "pindex" within
1262 * the specified object.
1264 * The object must be locked.
1267 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1272 VM_OBJECT_ASSERT_WLOCKED(object);
1273 KASSERT(m->object == NULL,
1274 ("vm_page_insert_after: page already inserted"));
1275 if (mpred != NULL) {
1276 KASSERT(mpred->object == object,
1277 ("vm_page_insert_after: object doesn't contain mpred"));
1278 KASSERT(mpred->pindex < pindex,
1279 ("vm_page_insert_after: mpred doesn't precede pindex"));
1280 msucc = TAILQ_NEXT(mpred, listq);
1282 msucc = TAILQ_FIRST(&object->memq);
1284 KASSERT(msucc->pindex > pindex,
1285 ("vm_page_insert_after: msucc doesn't succeed pindex"));
1288 * Record the object/offset pair in this page
1294 * Now link into the object's ordered list of backed pages.
1296 if (vm_radix_insert(&object->rtree, m)) {
1301 vm_page_insert_radixdone(m, object, mpred);
1306 * vm_page_insert_radixdone:
1308 * Complete page "m" insertion into the specified object after the
1309 * radix trie hooking.
1311 * The page "mpred" must precede the offset "m->pindex" within the
1314 * The object must be locked.
1317 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1320 VM_OBJECT_ASSERT_WLOCKED(object);
1321 KASSERT(object != NULL && m->object == object,
1322 ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1323 if (mpred != NULL) {
1324 KASSERT(mpred->object == object,
1325 ("vm_page_insert_after: object doesn't contain mpred"));
1326 KASSERT(mpred->pindex < m->pindex,
1327 ("vm_page_insert_after: mpred doesn't precede pindex"));
1331 TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1333 TAILQ_INSERT_HEAD(&object->memq, m, listq);
1336 * Show that the object has one more resident page.
1338 object->resident_page_count++;
1341 * Hold the vnode until the last page is released.
1343 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1344 vhold(object->handle);
1347 * Since we are inserting a new and possibly dirty page,
1348 * update the object's OBJ_MIGHTBEDIRTY flag.
1350 if (pmap_page_is_write_mapped(m))
1351 vm_object_set_writeable_dirty(object);
1357 * Removes the specified page from its containing object, but does not
1358 * invalidate any backing storage.
1360 * The object must be locked. The page must be locked if it is managed.
1363 vm_page_remove(vm_page_t m)
1368 if ((m->oflags & VPO_UNMANAGED) == 0)
1369 vm_page_assert_locked(m);
1370 if ((object = m->object) == NULL)
1372 VM_OBJECT_ASSERT_WLOCKED(object);
1373 if (vm_page_xbusied(m))
1374 vm_page_xunbusy_maybelocked(m);
1375 mrem = vm_radix_remove(&object->rtree, m->pindex);
1376 KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1379 * Now remove from the object's list of backed pages.
1381 TAILQ_REMOVE(&object->memq, m, listq);
1384 * And show that the object has one fewer resident page.
1386 object->resident_page_count--;
1389 * The vnode may now be recycled.
1391 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1392 vdrop(object->handle);
1400 * Returns the page associated with the object/offset
1401 * pair specified; if none is found, NULL is returned.
1403 * The object must be locked.
1406 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1409 VM_OBJECT_ASSERT_LOCKED(object);
1410 return (vm_radix_lookup(&object->rtree, pindex));
1414 * vm_page_find_least:
1416 * Returns the page associated with the object with least pindex
1417 * greater than or equal to the parameter pindex, or NULL.
1419 * The object must be locked.
1422 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1426 VM_OBJECT_ASSERT_LOCKED(object);
1427 if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1428 m = vm_radix_lookup_ge(&object->rtree, pindex);
1433 * Returns the given page's successor (by pindex) within the object if it is
1434 * resident; if none is found, NULL is returned.
1436 * The object must be locked.
1439 vm_page_next(vm_page_t m)
1443 VM_OBJECT_ASSERT_LOCKED(m->object);
1444 if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1445 MPASS(next->object == m->object);
1446 if (next->pindex != m->pindex + 1)
1453 * Returns the given page's predecessor (by pindex) within the object if it is
1454 * resident; if none is found, NULL is returned.
1456 * The object must be locked.
1459 vm_page_prev(vm_page_t m)
1463 VM_OBJECT_ASSERT_LOCKED(m->object);
1464 if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1465 MPASS(prev->object == m->object);
1466 if (prev->pindex != m->pindex - 1)
1473 * Uses the page mnew as a replacement for an existing page at index
1474 * pindex which must be already present in the object.
1476 * The existing page must not be on a paging queue.
1479 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1483 VM_OBJECT_ASSERT_WLOCKED(object);
1484 KASSERT(mnew->object == NULL,
1485 ("vm_page_replace: page already in object"));
1488 * This function mostly follows vm_page_insert() and
1489 * vm_page_remove() without the radix, object count and vnode
1490 * dance. Double check such functions for more comments.
1493 mnew->object = object;
1494 mnew->pindex = pindex;
1495 mold = vm_radix_replace(&object->rtree, mnew);
1496 KASSERT(mold->queue == PQ_NONE,
1497 ("vm_page_replace: mold is on a paging queue"));
1499 /* Keep the resident page list in sorted order. */
1500 TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1501 TAILQ_REMOVE(&object->memq, mold, listq);
1503 mold->object = NULL;
1504 vm_page_xunbusy_maybelocked(mold);
1507 * The object's resident_page_count does not change because we have
1508 * swapped one page for another, but OBJ_MIGHTBEDIRTY.
1510 if (pmap_page_is_write_mapped(mnew))
1511 vm_object_set_writeable_dirty(object);
1518 * Move the given memory entry from its
1519 * current object to the specified target object/offset.
1521 * Note: swap associated with the page must be invalidated by the move. We
1522 * have to do this for several reasons: (1) we aren't freeing the
1523 * page, (2) we are dirtying the page, (3) the VM system is probably
1524 * moving the page from object A to B, and will then later move
1525 * the backing store from A to B and we can't have a conflict.
1527 * Note: we *always* dirty the page. It is necessary both for the
1528 * fact that we moved it, and because we may be invalidating
1531 * The objects must be locked.
1534 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1539 VM_OBJECT_ASSERT_WLOCKED(new_object);
1541 mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1542 KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1543 ("vm_page_rename: pindex already renamed"));
1546 * Create a custom version of vm_page_insert() which does not depend
1547 * by m_prev and can cheat on the implementation aspects of the
1551 m->pindex = new_pindex;
1552 if (vm_radix_insert(&new_object->rtree, m)) {
1558 * The operation cannot fail anymore. The removal must happen before
1559 * the listq iterator is tainted.
1565 /* Return back to the new pindex to complete vm_page_insert(). */
1566 m->pindex = new_pindex;
1567 m->object = new_object;
1569 vm_page_insert_radixdone(m, new_object, mpred);
1577 * Allocate and return a page that is associated with the specified
1578 * object and offset pair. By default, this page is exclusive busied.
1580 * The caller must always specify an allocation class.
1582 * allocation classes:
1583 * VM_ALLOC_NORMAL normal process request
1584 * VM_ALLOC_SYSTEM system *really* needs a page
1585 * VM_ALLOC_INTERRUPT interrupt time request
1587 * optional allocation flags:
1588 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
1589 * intends to allocate
1590 * VM_ALLOC_NOBUSY do not exclusive busy the page
1591 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1592 * VM_ALLOC_NOOBJ page is not associated with an object and
1593 * should not be exclusive busy
1594 * VM_ALLOC_SBUSY shared busy the allocated page
1595 * VM_ALLOC_WIRED wire the allocated page
1596 * VM_ALLOC_ZERO prefer a zeroed page
1599 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1602 return (vm_page_alloc_after(object, pindex, req, object != NULL ?
1603 vm_radix_lookup_le(&object->rtree, pindex) : NULL));
1607 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1611 return (vm_page_alloc_domain_after(object, pindex, domain, req,
1612 object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) :
1617 * Allocate a page in the specified object with the given page index. To
1618 * optimize insertion of the page into the object, the caller must also specifiy
1619 * the resident page in the object with largest index smaller than the given
1620 * page index, or NULL if no such page exists.
1623 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex,
1624 int req, vm_page_t mpred)
1626 struct vm_domainset_iter di;
1630 vm_domainset_iter_page_init(&di, object, &domain, &req);
1632 m = vm_page_alloc_domain_after(object, pindex, domain, req,
1636 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
1642 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
1643 int req, vm_page_t mpred)
1646 int flags, req_class;
1649 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1650 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1651 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1652 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1653 ("inconsistent object(%p)/req(%x)", object, req));
1654 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
1655 ("Can't sleep and retry object insertion."));
1656 KASSERT(mpred == NULL || mpred->pindex < pindex,
1657 ("mpred %p doesn't precede pindex 0x%jx", mpred,
1658 (uintmax_t)pindex));
1660 VM_OBJECT_ASSERT_WLOCKED(object);
1662 req_class = req & VM_ALLOC_CLASS_MASK;
1665 * The page daemon is allowed to dig deeper into the free page list.
1667 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1668 req_class = VM_ALLOC_SYSTEM;
1671 * Allocate a page if the number of free pages exceeds the minimum
1672 * for the request class.
1676 mtx_lock(&vm_page_queue_free_mtx);
1677 if (vm_cnt.v_free_count > vm_cnt.v_free_reserved ||
1678 (req_class == VM_ALLOC_SYSTEM &&
1679 vm_cnt.v_free_count > vm_cnt.v_interrupt_free_min) ||
1680 (req_class == VM_ALLOC_INTERRUPT &&
1681 vm_cnt.v_free_count > 0)) {
1683 * Can we allocate the page from a reservation?
1685 #if VM_NRESERVLEVEL > 0
1686 if (object == NULL || (object->flags & (OBJ_COLORED |
1687 OBJ_FICTITIOUS)) != OBJ_COLORED || (m =
1688 vm_reserv_alloc_page(object, pindex, domain,
1693 * If not, allocate it from the free page queues.
1695 m = vm_phys_alloc_pages(domain, object != NULL ?
1696 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1697 #if VM_NRESERVLEVEL > 0
1698 if (m == NULL && vm_reserv_reclaim_inactive(domain)) {
1699 m = vm_phys_alloc_pages(domain,
1701 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1709 * Not allocatable, give up.
1711 if (vm_page_alloc_fail(object, req))
1717 * At this point we had better have found a good page.
1719 KASSERT(m != NULL, ("missing page"));
1720 free_count = vm_phys_freecnt_adj(m, -1);
1721 mtx_unlock(&vm_page_queue_free_mtx);
1722 vm_page_alloc_check(m);
1725 * Initialize the page. Only the PG_ZERO flag is inherited.
1728 if ((req & VM_ALLOC_ZERO) != 0)
1731 if ((req & VM_ALLOC_NODUMP) != 0)
1735 m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1737 m->busy_lock = VPB_UNBUSIED;
1738 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1739 m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1740 if ((req & VM_ALLOC_SBUSY) != 0)
1741 m->busy_lock = VPB_SHARERS_WORD(1);
1742 if (req & VM_ALLOC_WIRED) {
1744 * The page lock is not required for wiring a page until that
1745 * page is inserted into the object.
1747 atomic_add_int(&vm_cnt.v_wire_count, 1);
1752 if (object != NULL) {
1753 if (vm_page_insert_after(m, object, pindex, mpred)) {
1754 pagedaemon_wakeup();
1755 if (req & VM_ALLOC_WIRED) {
1756 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
1759 KASSERT(m->object == NULL, ("page %p has object", m));
1760 m->oflags = VPO_UNMANAGED;
1761 m->busy_lock = VPB_UNBUSIED;
1762 /* Don't change PG_ZERO. */
1763 vm_page_free_toq(m);
1764 if (req & VM_ALLOC_WAITFAIL) {
1765 VM_OBJECT_WUNLOCK(object);
1767 VM_OBJECT_WLOCK(object);
1772 /* Ignore device objects; the pager sets "memattr" for them. */
1773 if (object->memattr != VM_MEMATTR_DEFAULT &&
1774 (object->flags & OBJ_FICTITIOUS) == 0)
1775 pmap_page_set_memattr(m, object->memattr);
1780 * Don't wakeup too often - wakeup the pageout daemon when
1781 * we would be nearly out of memory.
1783 if (vm_paging_needed(free_count))
1784 pagedaemon_wakeup();
1790 * vm_page_alloc_contig:
1792 * Allocate a contiguous set of physical pages of the given size "npages"
1793 * from the free lists. All of the physical pages must be at or above
1794 * the given physical address "low" and below the given physical address
1795 * "high". The given value "alignment" determines the alignment of the
1796 * first physical page in the set. If the given value "boundary" is
1797 * non-zero, then the set of physical pages cannot cross any physical
1798 * address boundary that is a multiple of that value. Both "alignment"
1799 * and "boundary" must be a power of two.
1801 * If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1802 * then the memory attribute setting for the physical pages is configured
1803 * to the object's memory attribute setting. Otherwise, the memory
1804 * attribute setting for the physical pages is configured to "memattr",
1805 * overriding the object's memory attribute setting. However, if the
1806 * object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1807 * memory attribute setting for the physical pages cannot be configured
1808 * to VM_MEMATTR_DEFAULT.
1810 * The specified object may not contain fictitious pages.
1812 * The caller must always specify an allocation class.
1814 * allocation classes:
1815 * VM_ALLOC_NORMAL normal process request
1816 * VM_ALLOC_SYSTEM system *really* needs a page
1817 * VM_ALLOC_INTERRUPT interrupt time request
1819 * optional allocation flags:
1820 * VM_ALLOC_NOBUSY do not exclusive busy the page
1821 * VM_ALLOC_NODUMP do not include the page in a kernel core dump
1822 * VM_ALLOC_NOOBJ page is not associated with an object and
1823 * should not be exclusive busy
1824 * VM_ALLOC_SBUSY shared busy the allocated page
1825 * VM_ALLOC_WIRED wire the allocated page
1826 * VM_ALLOC_ZERO prefer a zeroed page
1829 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1830 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1831 vm_paddr_t boundary, vm_memattr_t memattr)
1833 struct vm_domainset_iter di;
1837 vm_domainset_iter_page_init(&di, object, &domain, &req);
1839 m = vm_page_alloc_contig_domain(object, pindex, domain, req,
1840 npages, low, high, alignment, boundary, memattr);
1843 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
1849 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1850 int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1851 vm_paddr_t boundary, vm_memattr_t memattr)
1853 vm_page_t m, m_ret, mpred;
1854 u_int busy_lock, flags, oflags;
1857 mpred = NULL; /* XXX: pacify gcc */
1858 KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1859 (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1860 ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1861 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1862 ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
1864 KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
1865 ("Can't sleep and retry object insertion."));
1866 if (object != NULL) {
1867 VM_OBJECT_ASSERT_WLOCKED(object);
1868 KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
1869 ("vm_page_alloc_contig: object %p has fictitious pages",
1872 KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
1873 req_class = req & VM_ALLOC_CLASS_MASK;
1876 * The page daemon is allowed to dig deeper into the free page list.
1878 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
1879 req_class = VM_ALLOC_SYSTEM;
1881 if (object != NULL) {
1882 mpred = vm_radix_lookup_le(&object->rtree, pindex);
1883 KASSERT(mpred == NULL || mpred->pindex != pindex,
1884 ("vm_page_alloc_contig: pindex already allocated"));
1888 * Can we allocate the pages without the number of free pages falling
1889 * below the lower bound for the allocation class?
1893 mtx_lock(&vm_page_queue_free_mtx);
1894 if (vm_cnt.v_free_count >= npages + vm_cnt.v_free_reserved ||
1895 (req_class == VM_ALLOC_SYSTEM &&
1896 vm_cnt.v_free_count >= npages + vm_cnt.v_interrupt_free_min) ||
1897 (req_class == VM_ALLOC_INTERRUPT &&
1898 vm_cnt.v_free_count >= npages)) {
1900 * Can we allocate the pages from a reservation?
1902 #if VM_NRESERVLEVEL > 0
1904 if (object == NULL || (object->flags & OBJ_COLORED) == 0 ||
1905 (m_ret = vm_reserv_alloc_contig(object, pindex, domain,
1906 npages, low, high, alignment, boundary, mpred)) == NULL)
1909 * If not, allocate them from the free page queues.
1911 m_ret = vm_phys_alloc_contig(domain, npages, low, high,
1912 alignment, boundary);
1913 #if VM_NRESERVLEVEL > 0
1914 if (m_ret == NULL && vm_reserv_reclaim_contig(
1915 domain, npages, low, high, alignment, boundary))
1919 if (m_ret == NULL) {
1920 if (vm_page_alloc_fail(object, req))
1924 vm_phys_freecnt_adj(m_ret, -npages);
1925 mtx_unlock(&vm_page_queue_free_mtx);
1926 for (m = m_ret; m < &m_ret[npages]; m++)
1927 vm_page_alloc_check(m);
1930 * Initialize the pages. Only the PG_ZERO flag is inherited.
1933 if ((req & VM_ALLOC_ZERO) != 0)
1935 if ((req & VM_ALLOC_NODUMP) != 0)
1937 oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1939 busy_lock = VPB_UNBUSIED;
1940 if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1941 busy_lock = VPB_SINGLE_EXCLUSIVER;
1942 if ((req & VM_ALLOC_SBUSY) != 0)
1943 busy_lock = VPB_SHARERS_WORD(1);
1944 if ((req & VM_ALLOC_WIRED) != 0)
1945 atomic_add_int(&vm_cnt.v_wire_count, npages);
1946 if (object != NULL) {
1947 if (object->memattr != VM_MEMATTR_DEFAULT &&
1948 memattr == VM_MEMATTR_DEFAULT)
1949 memattr = object->memattr;
1951 for (m = m_ret; m < &m_ret[npages]; m++) {
1953 m->flags = (m->flags | PG_NODUMP) & flags;
1954 m->busy_lock = busy_lock;
1955 if ((req & VM_ALLOC_WIRED) != 0)
1959 if (object != NULL) {
1960 if (vm_page_insert_after(m, object, pindex, mpred)) {
1961 pagedaemon_wakeup();
1962 if ((req & VM_ALLOC_WIRED) != 0)
1963 atomic_subtract_int(
1964 &vm_cnt.v_wire_count, npages);
1965 KASSERT(m->object == NULL,
1966 ("page %p has object", m));
1968 for (m = m_ret; m < &m_ret[npages]; m++) {
1970 (req & VM_ALLOC_WIRED) != 0)
1972 m->oflags = VPO_UNMANAGED;
1973 m->busy_lock = VPB_UNBUSIED;
1974 /* Don't change PG_ZERO. */
1975 vm_page_free_toq(m);
1977 if (req & VM_ALLOC_WAITFAIL) {
1978 VM_OBJECT_WUNLOCK(object);
1980 VM_OBJECT_WLOCK(object);
1987 if (memattr != VM_MEMATTR_DEFAULT)
1988 pmap_page_set_memattr(m, memattr);
1991 if (vm_paging_needed(vm_cnt.v_free_count))
1992 pagedaemon_wakeup();
1997 * Check a page that has been freshly dequeued from a freelist.
2000 vm_page_alloc_check(vm_page_t m)
2003 KASSERT(m->object == NULL, ("page %p has object", m));
2004 KASSERT(m->queue == PQ_NONE,
2005 ("page %p has unexpected queue %d", m, m->queue));
2006 KASSERT(m->wire_count == 0, ("page %p is wired", m));
2007 KASSERT(m->hold_count == 0, ("page %p is held", m));
2008 KASSERT(!vm_page_busied(m), ("page %p is busy", m));
2009 KASSERT(m->dirty == 0, ("page %p is dirty", m));
2010 KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2011 ("page %p has unexpected memattr %d",
2012 m, pmap_page_get_memattr(m)));
2013 KASSERT(m->valid == 0, ("free page %p is valid", m));
2017 * vm_page_alloc_freelist:
2019 * Allocate a physical page from the specified free page list.
2021 * The caller must always specify an allocation class.
2023 * allocation classes:
2024 * VM_ALLOC_NORMAL normal process request
2025 * VM_ALLOC_SYSTEM system *really* needs a page
2026 * VM_ALLOC_INTERRUPT interrupt time request
2028 * optional allocation flags:
2029 * VM_ALLOC_COUNT(number) the number of additional pages that the caller
2030 * intends to allocate
2031 * VM_ALLOC_WIRED wire the allocated page
2032 * VM_ALLOC_ZERO prefer a zeroed page
2035 vm_page_alloc_freelist(int freelist, int req)
2037 struct vm_domainset_iter di;
2041 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req);
2043 m = vm_page_alloc_freelist_domain(domain, freelist, req);
2046 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
2052 vm_page_alloc_freelist_domain(int domain, int freelist, int req)
2055 u_int flags, free_count;
2058 req_class = req & VM_ALLOC_CLASS_MASK;
2061 * The page daemon is allowed to dig deeper into the free page list.
2063 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2064 req_class = VM_ALLOC_SYSTEM;
2067 * Do not allocate reserved pages unless the req has asked for it.
2070 mtx_lock(&vm_page_queue_free_mtx);
2071 if (vm_cnt.v_free_count > vm_cnt.v_free_reserved ||
2072 (req_class == VM_ALLOC_SYSTEM &&
2073 vm_cnt.v_free_count > vm_cnt.v_interrupt_free_min) ||
2074 (req_class == VM_ALLOC_INTERRUPT &&
2075 vm_cnt.v_free_count > 0))
2076 m = vm_phys_alloc_freelist_pages(domain, freelist,
2077 VM_FREEPOOL_DIRECT, 0);
2079 if (vm_page_alloc_fail(NULL, req))
2083 free_count = vm_phys_freecnt_adj(m, -1);
2084 mtx_unlock(&vm_page_queue_free_mtx);
2085 vm_page_alloc_check(m);
2088 * Initialize the page. Only the PG_ZERO flag is inherited.
2092 if ((req & VM_ALLOC_ZERO) != 0)
2095 if ((req & VM_ALLOC_WIRED) != 0) {
2097 * The page lock is not required for wiring a page that does
2098 * not belong to an object.
2100 atomic_add_int(&vm_cnt.v_wire_count, 1);
2103 /* Unmanaged pages don't use "act_count". */
2104 m->oflags = VPO_UNMANAGED;
2105 if (vm_paging_needed(free_count))
2106 pagedaemon_wakeup();
2110 #define VPSC_ANY 0 /* No restrictions. */
2111 #define VPSC_NORESERV 1 /* Skip reservations; implies VPSC_NOSUPER. */
2112 #define VPSC_NOSUPER 2 /* Skip superpages. */
2115 * vm_page_scan_contig:
2117 * Scan vm_page_array[] between the specified entries "m_start" and
2118 * "m_end" for a run of contiguous physical pages that satisfy the
2119 * specified conditions, and return the lowest page in the run. The
2120 * specified "alignment" determines the alignment of the lowest physical
2121 * page in the run. If the specified "boundary" is non-zero, then the
2122 * run of physical pages cannot span a physical address that is a
2123 * multiple of "boundary".
2125 * "m_end" is never dereferenced, so it need not point to a vm_page
2126 * structure within vm_page_array[].
2128 * "npages" must be greater than zero. "m_start" and "m_end" must not
2129 * span a hole (or discontiguity) in the physical address space. Both
2130 * "alignment" and "boundary" must be a power of two.
2133 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2134 u_long alignment, vm_paddr_t boundary, int options)
2140 #if VM_NRESERVLEVEL > 0
2143 int m_inc, order, run_ext, run_len;
2145 KASSERT(npages > 0, ("npages is 0"));
2146 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2147 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2151 for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2152 KASSERT((m->flags & PG_MARKER) == 0,
2153 ("page %p is PG_MARKER", m));
2154 KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->wire_count == 1,
2155 ("fictitious page %p has invalid wire count", m));
2158 * If the current page would be the start of a run, check its
2159 * physical address against the end, alignment, and boundary
2160 * conditions. If it doesn't satisfy these conditions, either
2161 * terminate the scan or advance to the next page that
2162 * satisfies the failed condition.
2165 KASSERT(m_run == NULL, ("m_run != NULL"));
2166 if (m + npages > m_end)
2168 pa = VM_PAGE_TO_PHYS(m);
2169 if ((pa & (alignment - 1)) != 0) {
2170 m_inc = atop(roundup2(pa, alignment) - pa);
2173 if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
2175 m_inc = atop(roundup2(pa, boundary) - pa);
2179 KASSERT(m_run != NULL, ("m_run == NULL"));
2181 vm_page_change_lock(m, &m_mtx);
2184 if (m->wire_count != 0 || m->hold_count != 0)
2186 #if VM_NRESERVLEVEL > 0
2187 else if ((level = vm_reserv_level(m)) >= 0 &&
2188 (options & VPSC_NORESERV) != 0) {
2190 /* Advance to the end of the reservation. */
2191 pa = VM_PAGE_TO_PHYS(m);
2192 m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2196 else if ((object = m->object) != NULL) {
2198 * The page is considered eligible for relocation if
2199 * and only if it could be laundered or reclaimed by
2202 if (!VM_OBJECT_TRYRLOCK(object)) {
2204 VM_OBJECT_RLOCK(object);
2206 if (m->object != object) {
2208 * The page may have been freed.
2210 VM_OBJECT_RUNLOCK(object);
2212 } else if (m->wire_count != 0 ||
2213 m->hold_count != 0) {
2218 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2219 ("page %p is PG_UNHOLDFREE", m));
2220 /* Don't care: PG_NODUMP, PG_ZERO. */
2221 if (object->type != OBJT_DEFAULT &&
2222 object->type != OBJT_SWAP &&
2223 object->type != OBJT_VNODE) {
2225 #if VM_NRESERVLEVEL > 0
2226 } else if ((options & VPSC_NOSUPER) != 0 &&
2227 (level = vm_reserv_level_iffullpop(m)) >= 0) {
2229 /* Advance to the end of the superpage. */
2230 pa = VM_PAGE_TO_PHYS(m);
2231 m_inc = atop(roundup2(pa + 1,
2232 vm_reserv_size(level)) - pa);
2234 } else if (object->memattr == VM_MEMATTR_DEFAULT &&
2235 m->queue != PQ_NONE && !vm_page_busied(m)) {
2237 * The page is allocated but eligible for
2238 * relocation. Extend the current run by one
2241 KASSERT(pmap_page_get_memattr(m) ==
2243 ("page %p has an unexpected memattr", m));
2244 KASSERT((m->oflags & (VPO_SWAPINPROG |
2245 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2246 ("page %p has unexpected oflags", m));
2247 /* Don't care: VPO_NOSYNC. */
2252 VM_OBJECT_RUNLOCK(object);
2253 #if VM_NRESERVLEVEL > 0
2254 } else if (level >= 0) {
2256 * The page is reserved but not yet allocated. In
2257 * other words, it is still free. Extend the current
2262 } else if ((order = m->order) < VM_NFREEORDER) {
2264 * The page is enqueued in the physical memory
2265 * allocator's free page queues. Moreover, it is the
2266 * first page in a power-of-two-sized run of
2267 * contiguous free pages. Add these pages to the end
2268 * of the current run, and jump ahead.
2270 run_ext = 1 << order;
2274 * Skip the page for one of the following reasons: (1)
2275 * It is enqueued in the physical memory allocator's
2276 * free page queues. However, it is not the first
2277 * page in a run of contiguous free pages. (This case
2278 * rarely occurs because the scan is performed in
2279 * ascending order.) (2) It is not reserved, and it is
2280 * transitioning from free to allocated. (Conversely,
2281 * the transition from allocated to free for managed
2282 * pages is blocked by the page lock.) (3) It is
2283 * allocated but not contained by an object and not
2284 * wired, e.g., allocated by Xen's balloon driver.
2290 * Extend or reset the current run of pages.
2305 if (run_len >= npages)
2311 * vm_page_reclaim_run:
2313 * Try to relocate each of the allocated virtual pages within the
2314 * specified run of physical pages to a new physical address. Free the
2315 * physical pages underlying the relocated virtual pages. A virtual page
2316 * is relocatable if and only if it could be laundered or reclaimed by
2317 * the page daemon. Whenever possible, a virtual page is relocated to a
2318 * physical address above "high".
2320 * Returns 0 if every physical page within the run was already free or
2321 * just freed by a successful relocation. Otherwise, returns a non-zero
2322 * value indicating why the last attempt to relocate a virtual page was
2325 * "req_class" must be an allocation class.
2328 vm_page_reclaim_run(int req_class, u_long npages, vm_page_t m_run,
2332 struct spglist free;
2335 vm_page_t m, m_end, m_new;
2336 int error, order, req;
2338 KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2339 ("req_class is not an allocation class"));
2343 m_end = m_run + npages;
2345 for (; error == 0 && m < m_end; m++) {
2346 KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2347 ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2350 * Avoid releasing and reacquiring the same page lock.
2352 vm_page_change_lock(m, &m_mtx);
2354 if (m->wire_count != 0 || m->hold_count != 0)
2356 else if ((object = m->object) != NULL) {
2358 * The page is relocated if and only if it could be
2359 * laundered or reclaimed by the page daemon.
2361 if (!VM_OBJECT_TRYWLOCK(object)) {
2363 VM_OBJECT_WLOCK(object);
2365 if (m->object != object) {
2367 * The page may have been freed.
2369 VM_OBJECT_WUNLOCK(object);
2371 } else if (m->wire_count != 0 ||
2372 m->hold_count != 0) {
2377 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2378 ("page %p is PG_UNHOLDFREE", m));
2379 /* Don't care: PG_NODUMP, PG_ZERO. */
2380 if (object->type != OBJT_DEFAULT &&
2381 object->type != OBJT_SWAP &&
2382 object->type != OBJT_VNODE)
2384 else if (object->memattr != VM_MEMATTR_DEFAULT)
2386 else if (m->queue != PQ_NONE && !vm_page_busied(m)) {
2387 KASSERT(pmap_page_get_memattr(m) ==
2389 ("page %p has an unexpected memattr", m));
2390 KASSERT((m->oflags & (VPO_SWAPINPROG |
2391 VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2392 ("page %p has unexpected oflags", m));
2393 /* Don't care: VPO_NOSYNC. */
2394 if (m->valid != 0) {
2396 * First, try to allocate a new page
2397 * that is above "high". Failing
2398 * that, try to allocate a new page
2399 * that is below "m_run". Allocate
2400 * the new page between the end of
2401 * "m_run" and "high" only as a last
2404 req = req_class | VM_ALLOC_NOOBJ;
2405 if ((m->flags & PG_NODUMP) != 0)
2406 req |= VM_ALLOC_NODUMP;
2407 if (trunc_page(high) !=
2408 ~(vm_paddr_t)PAGE_MASK) {
2409 m_new = vm_page_alloc_contig(
2414 VM_MEMATTR_DEFAULT);
2417 if (m_new == NULL) {
2418 pa = VM_PAGE_TO_PHYS(m_run);
2419 m_new = vm_page_alloc_contig(
2421 0, pa - 1, PAGE_SIZE, 0,
2422 VM_MEMATTR_DEFAULT);
2424 if (m_new == NULL) {
2426 m_new = vm_page_alloc_contig(
2428 pa, high, PAGE_SIZE, 0,
2429 VM_MEMATTR_DEFAULT);
2431 if (m_new == NULL) {
2435 KASSERT(m_new->wire_count == 0,
2436 ("page %p is wired", m));
2439 * Replace "m" with the new page. For
2440 * vm_page_replace(), "m" must be busy
2441 * and dequeued. Finally, change "m"
2442 * as if vm_page_free() was called.
2444 if (object->ref_count != 0)
2446 m_new->aflags = m->aflags;
2447 KASSERT(m_new->oflags == VPO_UNMANAGED,
2448 ("page %p is managed", m));
2449 m_new->oflags = m->oflags & VPO_NOSYNC;
2450 pmap_copy_page(m, m_new);
2451 m_new->valid = m->valid;
2452 m_new->dirty = m->dirty;
2453 m->flags &= ~PG_ZERO;
2456 vm_page_replace_checked(m_new, object,
2462 * The new page must be deactivated
2463 * before the object is unlocked.
2465 vm_page_change_lock(m_new, &m_mtx);
2466 vm_page_deactivate(m_new);
2468 m->flags &= ~PG_ZERO;
2471 KASSERT(m->dirty == 0,
2472 ("page %p is dirty", m));
2474 SLIST_INSERT_HEAD(&free, m, plinks.s.ss);
2478 VM_OBJECT_WUNLOCK(object);
2480 mtx_lock(&vm_page_queue_free_mtx);
2482 if (order < VM_NFREEORDER) {
2484 * The page is enqueued in the physical memory
2485 * allocator's free page queues. Moreover, it
2486 * is the first page in a power-of-two-sized
2487 * run of contiguous free pages. Jump ahead
2488 * to the last page within that run, and
2489 * continue from there.
2491 m += (1 << order) - 1;
2493 #if VM_NRESERVLEVEL > 0
2494 else if (vm_reserv_is_page_free(m))
2497 mtx_unlock(&vm_page_queue_free_mtx);
2498 if (order == VM_NFREEORDER)
2504 if ((m = SLIST_FIRST(&free)) != NULL) {
2505 mtx_lock(&vm_page_queue_free_mtx);
2507 SLIST_REMOVE_HEAD(&free, plinks.s.ss);
2508 vm_page_free_phys(m);
2509 } while ((m = SLIST_FIRST(&free)) != NULL);
2510 vm_page_free_wakeup();
2511 mtx_unlock(&vm_page_queue_free_mtx);
2518 CTASSERT(powerof2(NRUNS));
2520 #define RUN_INDEX(count) ((count) & (NRUNS - 1))
2522 #define MIN_RECLAIM 8
2525 * vm_page_reclaim_contig:
2527 * Reclaim allocated, contiguous physical memory satisfying the specified
2528 * conditions by relocating the virtual pages using that physical memory.
2529 * Returns true if reclamation is successful and false otherwise. Since
2530 * relocation requires the allocation of physical pages, reclamation may
2531 * fail due to a shortage of free pages. When reclamation fails, callers
2532 * are expected to perform VM_WAIT before retrying a failed allocation
2533 * operation, e.g., vm_page_alloc_contig().
2535 * The caller must always specify an allocation class through "req".
2537 * allocation classes:
2538 * VM_ALLOC_NORMAL normal process request
2539 * VM_ALLOC_SYSTEM system *really* needs a page
2540 * VM_ALLOC_INTERRUPT interrupt time request
2542 * The optional allocation flags are ignored.
2544 * "npages" must be greater than zero. Both "alignment" and "boundary"
2545 * must be a power of two.
2548 vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
2549 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
2551 vm_paddr_t curr_low;
2552 vm_page_t m_run, m_runs[NRUNS];
2553 u_long count, reclaimed;
2554 int error, i, options, req_class;
2556 KASSERT(npages > 0, ("npages is 0"));
2557 KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2558 KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2559 req_class = req & VM_ALLOC_CLASS_MASK;
2562 * The page daemon is allowed to dig deeper into the free page list.
2564 if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2565 req_class = VM_ALLOC_SYSTEM;
2568 * Return if the number of free pages cannot satisfy the requested
2571 count = vm_cnt.v_free_count;
2572 if (count < npages + vm_cnt.v_free_reserved || (count < npages +
2573 vm_cnt.v_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
2574 (count < npages && req_class == VM_ALLOC_INTERRUPT))
2578 * Scan up to three times, relaxing the restrictions ("options") on
2579 * the reclamation of reservations and superpages each time.
2581 for (options = VPSC_NORESERV;;) {
2583 * Find the highest runs that satisfy the given constraints
2584 * and restrictions, and record them in "m_runs".
2589 m_run = vm_phys_scan_contig(domain, npages, curr_low,
2590 high, alignment, boundary, options);
2593 curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages);
2594 m_runs[RUN_INDEX(count)] = m_run;
2599 * Reclaim the highest runs in LIFO (descending) order until
2600 * the number of reclaimed pages, "reclaimed", is at least
2601 * MIN_RECLAIM. Reset "reclaimed" each time because each
2602 * reclamation is idempotent, and runs will (likely) recur
2603 * from one scan to the next as restrictions are relaxed.
2606 for (i = 0; count > 0 && i < NRUNS; i++) {
2608 m_run = m_runs[RUN_INDEX(count)];
2609 error = vm_page_reclaim_run(req_class, npages, m_run,
2612 reclaimed += npages;
2613 if (reclaimed >= MIN_RECLAIM)
2619 * Either relax the restrictions on the next scan or return if
2620 * the last scan had no restrictions.
2622 if (options == VPSC_NORESERV)
2623 options = VPSC_NOSUPER;
2624 else if (options == VPSC_NOSUPER)
2626 else if (options == VPSC_ANY)
2627 return (reclaimed != 0);
2632 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
2633 u_long alignment, vm_paddr_t boundary)
2635 struct vm_domainset_iter di;
2639 vm_domainset_iter_page_init(&di, kernel_object, &domain, &req);
2641 ret = vm_page_reclaim_contig_domain(domain, req, npages, low,
2642 high, alignment, boundary);
2645 } while (vm_domainset_iter_page(&di, &domain, &req) == 0);
2652 * vm_wait: (also see VM_WAIT macro)
2654 * Sleep until free pages are available for allocation.
2655 * - Called in various places before memory allocations.
2661 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2662 if (curproc == pageproc) {
2663 vm_pageout_pages_needed = 1;
2664 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx,
2665 PDROP | PSWP, "VMWait", 0);
2667 if (pageproc == NULL)
2668 panic("vm_wait in early boot");
2669 pagedaemon_wait(PVM, "vmwait");
2677 mtx_lock(&vm_page_queue_free_mtx);
2682 * vm_page_alloc_fail:
2684 * Called when a page allocation function fails. Informs the
2685 * pagedaemon and performs the requested wait. Requires the
2686 * page_queue_free and object lock on entry. Returns with the
2687 * object lock held and free lock released. Returns an error when
2688 * retry is necessary.
2692 vm_page_alloc_fail(vm_object_t object, int req)
2695 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2697 atomic_add_int(&vm_pageout_deficit,
2698 max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
2699 if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
2701 VM_OBJECT_WUNLOCK(object);
2704 VM_OBJECT_WLOCK(object);
2705 if (req & VM_ALLOC_WAITOK)
2708 mtx_unlock(&vm_page_queue_free_mtx);
2709 pagedaemon_wakeup();
2715 * vm_waitpfault: (also see VM_WAITPFAULT macro)
2717 * Sleep until free pages are available for allocation.
2718 * - Called only in vm_fault so that processes page faulting
2719 * can be easily tracked.
2720 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
2721 * processes will be able to grab memory first. Do not change
2722 * this balance without careful testing first.
2728 mtx_lock(&vm_page_queue_free_mtx);
2729 pagedaemon_wait(PUSER, "pfault");
2732 struct vm_pagequeue *
2733 vm_page_pagequeue(vm_page_t m)
2736 if (vm_page_in_laundry(m))
2737 return (&vm_dom[0].vmd_pagequeues[m->queue]);
2739 return (&vm_phys_domain(m)->vmd_pagequeues[m->queue]);
2745 * Remove the given page from its current page queue.
2747 * The page must be locked.
2750 vm_page_dequeue(vm_page_t m)
2752 struct vm_pagequeue *pq;
2754 vm_page_assert_locked(m);
2755 KASSERT(m->queue < PQ_COUNT, ("vm_page_dequeue: page %p is not queued",
2757 pq = vm_page_pagequeue(m);
2758 vm_pagequeue_lock(pq);
2760 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2761 vm_pagequeue_cnt_dec(pq);
2762 vm_pagequeue_unlock(pq);
2766 * vm_page_dequeue_locked:
2768 * Remove the given page from its current page queue.
2770 * The page and page queue must be locked.
2773 vm_page_dequeue_locked(vm_page_t m)
2775 struct vm_pagequeue *pq;
2777 vm_page_lock_assert(m, MA_OWNED);
2778 pq = vm_page_pagequeue(m);
2779 vm_pagequeue_assert_locked(pq);
2781 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2782 vm_pagequeue_cnt_dec(pq);
2788 * Add the given page to the specified page queue.
2790 * The page must be locked.
2793 vm_page_enqueue(uint8_t queue, vm_page_t m)
2795 struct vm_pagequeue *pq;
2797 vm_page_lock_assert(m, MA_OWNED);
2798 KASSERT(queue < PQ_COUNT,
2799 ("vm_page_enqueue: invalid queue %u request for page %p",
2801 if (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE)
2802 pq = &vm_dom[0].vmd_pagequeues[queue];
2804 pq = &vm_phys_domain(m)->vmd_pagequeues[queue];
2805 vm_pagequeue_lock(pq);
2807 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2808 vm_pagequeue_cnt_inc(pq);
2809 vm_pagequeue_unlock(pq);
2815 * Move the given page to the tail of its current page queue.
2817 * The page must be locked.
2820 vm_page_requeue(vm_page_t m)
2822 struct vm_pagequeue *pq;
2824 vm_page_lock_assert(m, MA_OWNED);
2825 KASSERT(m->queue != PQ_NONE,
2826 ("vm_page_requeue: page %p is not queued", m));
2827 pq = vm_page_pagequeue(m);
2828 vm_pagequeue_lock(pq);
2829 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2830 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2831 vm_pagequeue_unlock(pq);
2835 * vm_page_requeue_locked:
2837 * Move the given page to the tail of its current page queue.
2839 * The page queue must be locked.
2842 vm_page_requeue_locked(vm_page_t m)
2844 struct vm_pagequeue *pq;
2846 KASSERT(m->queue != PQ_NONE,
2847 ("vm_page_requeue_locked: page %p is not queued", m));
2848 pq = vm_page_pagequeue(m);
2849 vm_pagequeue_assert_locked(pq);
2850 TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
2851 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
2857 * Put the specified page on the active list (if appropriate).
2858 * Ensure that act_count is at least ACT_INIT but do not otherwise
2861 * The page must be locked.
2864 vm_page_activate(vm_page_t m)
2868 vm_page_lock_assert(m, MA_OWNED);
2869 if ((queue = m->queue) != PQ_ACTIVE) {
2870 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
2871 if (m->act_count < ACT_INIT)
2872 m->act_count = ACT_INIT;
2873 if (queue != PQ_NONE)
2875 vm_page_enqueue(PQ_ACTIVE, m);
2877 KASSERT(queue == PQ_NONE,
2878 ("vm_page_activate: wired page %p is queued", m));
2880 if (m->act_count < ACT_INIT)
2881 m->act_count = ACT_INIT;
2886 * vm_page_free_wakeup:
2888 * Helper routine for vm_page_free_toq(). This routine is called
2889 * when a page is added to the free queues.
2891 * The page queues must be locked.
2894 vm_page_free_wakeup(void)
2897 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
2899 * if pageout daemon needs pages, then tell it that there are
2902 if (vm_pageout_pages_needed &&
2903 vm_cnt.v_free_count >= vm_cnt.v_pageout_free_min) {
2904 wakeup(&vm_pageout_pages_needed);
2905 vm_pageout_pages_needed = 0;
2908 * wakeup processes that are waiting on memory if we hit a
2909 * high water mark. And wakeup scheduler process if we have
2910 * lots of memory. this process will swapin processes.
2912 if (vm_pages_needed && !vm_page_count_min()) {
2913 vm_pages_needed = false;
2914 wakeup(&vm_cnt.v_free_count);
2919 * vm_page_free_prep:
2921 * Prepares the given page to be put on the free list,
2922 * disassociating it from any VM object. The caller may return
2923 * the page to the free list only if this function returns true.
2925 * The object must be locked. The page must be locked if it is
2926 * managed. For a queued managed page, the pagequeue_locked
2927 * argument specifies whether the page queue is already locked.
2930 vm_page_free_prep(vm_page_t m, bool pagequeue_locked)
2933 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
2934 if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
2937 p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
2938 for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
2939 KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
2940 m, i, (uintmax_t)*p));
2943 if ((m->oflags & VPO_UNMANAGED) == 0) {
2944 vm_page_lock_assert(m, MA_OWNED);
2945 KASSERT(!pmap_page_is_mapped(m),
2946 ("vm_page_free_toq: freeing mapped page %p", m));
2948 KASSERT(m->queue == PQ_NONE,
2949 ("vm_page_free_toq: unmanaged page %p is queued", m));
2950 VM_CNT_INC(v_tfree);
2952 if (vm_page_sbusied(m))
2953 panic("vm_page_free: freeing busy page %p", m);
2958 * If fictitious remove object association and
2961 if ((m->flags & PG_FICTITIOUS) != 0) {
2962 KASSERT(m->wire_count == 1,
2963 ("fictitious page %p is not wired", m));
2964 KASSERT(m->queue == PQ_NONE,
2965 ("fictitious page %p is queued", m));
2969 if (m->queue != PQ_NONE) {
2970 if (pagequeue_locked)
2971 vm_page_dequeue_locked(m);
2978 if (m->wire_count != 0)
2979 panic("vm_page_free: freeing wired page %p", m);
2980 if (m->hold_count != 0) {
2981 m->flags &= ~PG_ZERO;
2982 KASSERT((m->flags & PG_UNHOLDFREE) == 0,
2983 ("vm_page_free: freeing PG_UNHOLDFREE page %p", m));
2984 m->flags |= PG_UNHOLDFREE;
2989 * Restore the default memory attribute to the page.
2991 if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
2992 pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
2998 * Insert the page into the physical memory allocator's free page
2999 * queues. This is the last step to free a page.
3002 vm_page_free_phys(vm_page_t m)
3005 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
3007 vm_phys_freecnt_adj(m, 1);
3008 #if VM_NRESERVLEVEL > 0
3009 if (!vm_reserv_free_page(m))
3011 vm_phys_free_pages(m, 0);
3015 vm_page_free_phys_pglist(struct pglist *tq)
3019 if (TAILQ_EMPTY(tq))
3021 mtx_lock(&vm_page_queue_free_mtx);
3022 TAILQ_FOREACH(m, tq, listq)
3023 vm_page_free_phys(m);
3024 vm_page_free_wakeup();
3025 mtx_unlock(&vm_page_queue_free_mtx);
3031 * Returns the given page to the free list, disassociating it
3032 * from any VM object.
3034 * The object must be locked. The page must be locked if it is
3038 vm_page_free_toq(vm_page_t m)
3041 if (!vm_page_free_prep(m, false))
3043 mtx_lock(&vm_page_queue_free_mtx);
3044 vm_page_free_phys(m);
3045 vm_page_free_wakeup();
3046 mtx_unlock(&vm_page_queue_free_mtx);
3052 * Mark this page as wired down by yet
3053 * another map, removing it from paging queues
3056 * If the page is fictitious, then its wire count must remain one.
3058 * The page must be locked.
3061 vm_page_wire(vm_page_t m)
3065 * Only bump the wire statistics if the page is not already wired,
3066 * and only unqueue the page if it is on some queue (if it is unmanaged
3067 * it is already off the queues).
3069 vm_page_lock_assert(m, MA_OWNED);
3070 if ((m->flags & PG_FICTITIOUS) != 0) {
3071 KASSERT(m->wire_count == 1,
3072 ("vm_page_wire: fictitious page %p's wire count isn't one",
3076 if (m->wire_count == 0) {
3077 KASSERT((m->oflags & VPO_UNMANAGED) == 0 ||
3078 m->queue == PQ_NONE,
3079 ("vm_page_wire: unmanaged page %p is queued", m));
3081 atomic_add_int(&vm_cnt.v_wire_count, 1);
3084 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
3090 * Release one wiring of the specified page, potentially allowing it to be
3091 * paged out. Returns TRUE if the number of wirings transitions to zero and
3094 * Only managed pages belonging to an object can be paged out. If the number
3095 * of wirings transitions to zero and the page is eligible for page out, then
3096 * the page is added to the specified paging queue (unless PQ_NONE is
3099 * If a page is fictitious, then its wire count must always be one.
3101 * A managed page must be locked.
3104 vm_page_unwire(vm_page_t m, uint8_t queue)
3107 KASSERT(queue < PQ_COUNT || queue == PQ_NONE,
3108 ("vm_page_unwire: invalid queue %u request for page %p",
3110 if ((m->oflags & VPO_UNMANAGED) == 0)
3111 vm_page_assert_locked(m);
3112 if ((m->flags & PG_FICTITIOUS) != 0) {
3113 KASSERT(m->wire_count == 1,
3114 ("vm_page_unwire: fictitious page %p's wire count isn't one", m));
3117 if (m->wire_count > 0) {
3119 if (m->wire_count == 0) {
3120 atomic_subtract_int(&vm_cnt.v_wire_count, 1);
3121 if ((m->oflags & VPO_UNMANAGED) == 0 &&
3122 m->object != NULL && queue != PQ_NONE)
3123 vm_page_enqueue(queue, m);
3128 panic("vm_page_unwire: page %p's wire count is zero", m);
3132 * Move the specified page to the inactive queue.
3134 * Normally, "noreuse" is FALSE, resulting in LRU ordering of the inactive
3135 * queue. However, setting "noreuse" to TRUE will accelerate the specified
3136 * page's reclamation, but it will not unmap the page from any address space.
3137 * This is implemented by inserting the page near the head of the inactive
3138 * queue, using a marker page to guide FIFO insertion ordering.
3140 * The page must be locked.
3143 _vm_page_deactivate(vm_page_t m, boolean_t noreuse)
3145 struct vm_pagequeue *pq;
3148 vm_page_assert_locked(m);
3151 * Ignore if the page is already inactive, unless it is unlikely to be
3154 if ((queue = m->queue) == PQ_INACTIVE && !noreuse)
3156 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3157 pq = &vm_phys_domain(m)->vmd_pagequeues[PQ_INACTIVE];
3158 /* Avoid multiple acquisitions of the inactive queue lock. */
3159 if (queue == PQ_INACTIVE) {
3160 vm_pagequeue_lock(pq);
3161 vm_page_dequeue_locked(m);
3163 if (queue != PQ_NONE)
3165 vm_pagequeue_lock(pq);
3167 m->queue = PQ_INACTIVE;
3169 TAILQ_INSERT_BEFORE(&vm_phys_domain(m)->vmd_inacthead,
3172 TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3173 vm_pagequeue_cnt_inc(pq);
3174 vm_pagequeue_unlock(pq);
3179 * Move the specified page to the inactive queue.
3181 * The page must be locked.
3184 vm_page_deactivate(vm_page_t m)
3187 _vm_page_deactivate(m, FALSE);
3191 * Move the specified page to the inactive queue with the expectation
3192 * that it is unlikely to be reused.
3194 * The page must be locked.
3197 vm_page_deactivate_noreuse(vm_page_t m)
3200 _vm_page_deactivate(m, TRUE);
3206 * Put a page in the laundry.
3209 vm_page_launder(vm_page_t m)
3213 vm_page_assert_locked(m);
3214 if ((queue = m->queue) != PQ_LAUNDRY) {
3215 if (m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0) {
3216 if (queue != PQ_NONE)
3218 vm_page_enqueue(PQ_LAUNDRY, m);
3220 KASSERT(queue == PQ_NONE,
3221 ("wired page %p is queued", m));
3226 * vm_page_unswappable
3228 * Put a page in the PQ_UNSWAPPABLE holding queue.
3231 vm_page_unswappable(vm_page_t m)
3234 vm_page_assert_locked(m);
3235 KASSERT(m->wire_count == 0 && (m->oflags & VPO_UNMANAGED) == 0,
3236 ("page %p already unswappable", m));
3237 if (m->queue != PQ_NONE)
3239 vm_page_enqueue(PQ_UNSWAPPABLE, m);
3243 * Attempt to free the page. If it cannot be freed, do nothing. Returns true
3244 * if the page is freed and false otherwise.
3246 * The page must be managed. The page and its containing object must be
3250 vm_page_try_to_free(vm_page_t m)
3253 vm_page_assert_locked(m);
3254 VM_OBJECT_ASSERT_WLOCKED(m->object);
3255 KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("page %p is unmanaged", m));
3256 if (m->dirty != 0 || m->hold_count != 0 || m->wire_count != 0 ||
3259 if (m->object->ref_count != 0) {
3271 * Apply the specified advice to the given page.
3273 * The object and page must be locked.
3276 vm_page_advise(vm_page_t m, int advice)
3279 vm_page_assert_locked(m);
3280 VM_OBJECT_ASSERT_WLOCKED(m->object);
3281 if (advice == MADV_FREE)
3283 * Mark the page clean. This will allow the page to be freed
3284 * without first paging it out. MADV_FREE pages are often
3285 * quickly reused by malloc(3), so we do not do anything that
3286 * would result in a page fault on a later access.
3289 else if (advice != MADV_DONTNEED) {
3290 if (advice == MADV_WILLNEED)
3291 vm_page_activate(m);
3296 * Clear any references to the page. Otherwise, the page daemon will
3297 * immediately reactivate the page.
3299 vm_page_aflag_clear(m, PGA_REFERENCED);
3301 if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
3305 * Place clean pages near the head of the inactive queue rather than
3306 * the tail, thus defeating the queue's LRU operation and ensuring that
3307 * the page will be reused quickly. Dirty pages not already in the
3308 * laundry are moved there.
3311 vm_page_deactivate_noreuse(m);
3317 * Grab a page, waiting until we are waken up due to the page
3318 * changing state. We keep on waiting, if the page continues
3319 * to be in the object. If the page doesn't exist, first allocate it
3320 * and then conditionally zero it.
3322 * This routine may sleep.
3324 * The object must be locked on entry. The lock will, however, be released
3325 * and reacquired if the routine sleeps.
3328 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
3334 VM_OBJECT_ASSERT_WLOCKED(object);
3335 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3336 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3337 ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
3338 pflags = allocflags &
3339 ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
3340 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
3341 pflags |= VM_ALLOC_WAITFAIL;
3343 if ((m = vm_page_lookup(object, pindex)) != NULL) {
3344 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3345 vm_page_xbusied(m) : vm_page_busied(m);
3347 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3350 * Reference the page before unlocking and
3351 * sleeping so that the page daemon is less
3352 * likely to reclaim it.
3354 vm_page_aflag_set(m, PGA_REFERENCED);
3356 VM_OBJECT_WUNLOCK(object);
3357 vm_page_busy_sleep(m, "pgrbwt", (allocflags &
3358 VM_ALLOC_IGN_SBUSY) != 0);
3359 VM_OBJECT_WLOCK(object);
3362 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3368 (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
3370 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3375 m = vm_page_alloc(object, pindex, pflags);
3377 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3381 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
3387 * Return the specified range of pages from the given object. For each
3388 * page offset within the range, if a page already exists within the object
3389 * at that offset and it is busy, then wait for it to change state. If,
3390 * instead, the page doesn't exist, then allocate it.
3392 * The caller must always specify an allocation class.
3394 * allocation classes:
3395 * VM_ALLOC_NORMAL normal process request
3396 * VM_ALLOC_SYSTEM system *really* needs the pages
3398 * The caller must always specify that the pages are to be busied and/or
3401 * optional allocation flags:
3402 * VM_ALLOC_IGN_SBUSY do not sleep on soft busy pages
3403 * VM_ALLOC_NOBUSY do not exclusive busy the page
3404 * VM_ALLOC_NOWAIT do not sleep
3405 * VM_ALLOC_SBUSY set page to sbusy state
3406 * VM_ALLOC_WIRED wire the pages
3407 * VM_ALLOC_ZERO zero and validate any invalid pages
3409 * If VM_ALLOC_NOWAIT is not specified, this routine may sleep. Otherwise, it
3410 * may return a partial prefix of the requested range.
3413 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
3414 vm_page_t *ma, int count)
3421 VM_OBJECT_ASSERT_WLOCKED(object);
3422 KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0,
3423 ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed"));
3424 KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
3425 (allocflags & VM_ALLOC_WIRED) != 0,
3426 ("vm_page_grab_pages: the pages must be busied or wired"));
3427 KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
3428 (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
3429 ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch"));
3432 pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK |
3433 VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY);
3434 if ((allocflags & VM_ALLOC_NOWAIT) == 0)
3435 pflags |= VM_ALLOC_WAITFAIL;
3438 m = vm_radix_lookup_le(&object->rtree, pindex + i);
3439 if (m == NULL || m->pindex != pindex + i) {
3443 mpred = TAILQ_PREV(m, pglist, listq);
3444 for (; i < count; i++) {
3446 sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
3447 vm_page_xbusied(m) : vm_page_busied(m);
3449 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3452 * Reference the page before unlocking and
3453 * sleeping so that the page daemon is less
3454 * likely to reclaim it.
3456 vm_page_aflag_set(m, PGA_REFERENCED);
3458 VM_OBJECT_WUNLOCK(object);
3459 vm_page_busy_sleep(m, "grbmaw", (allocflags &
3460 VM_ALLOC_IGN_SBUSY) != 0);
3461 VM_OBJECT_WLOCK(object);
3464 if ((allocflags & VM_ALLOC_WIRED) != 0) {
3469 if ((allocflags & (VM_ALLOC_NOBUSY |
3470 VM_ALLOC_SBUSY)) == 0)
3472 if ((allocflags & VM_ALLOC_SBUSY) != 0)
3475 m = vm_page_alloc_after(object, pindex + i,
3476 pflags | VM_ALLOC_COUNT(count - i), mpred);
3478 if ((allocflags & VM_ALLOC_NOWAIT) != 0)
3483 if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) {
3484 if ((m->flags & PG_ZERO) == 0)
3486 m->valid = VM_PAGE_BITS_ALL;
3489 m = vm_page_next(m);
3495 * Mapping function for valid or dirty bits in a page.
3497 * Inputs are required to range within a page.
3500 vm_page_bits(int base, int size)
3506 base + size <= PAGE_SIZE,
3507 ("vm_page_bits: illegal base/size %d/%d", base, size)
3510 if (size == 0) /* handle degenerate case */
3513 first_bit = base >> DEV_BSHIFT;
3514 last_bit = (base + size - 1) >> DEV_BSHIFT;
3516 return (((vm_page_bits_t)2 << last_bit) -
3517 ((vm_page_bits_t)1 << first_bit));
3521 * vm_page_set_valid_range:
3523 * Sets portions of a page valid. The arguments are expected
3524 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3525 * of any partial chunks touched by the range. The invalid portion of
3526 * such chunks will be zeroed.
3528 * (base + size) must be less then or equal to PAGE_SIZE.
3531 vm_page_set_valid_range(vm_page_t m, int base, int size)
3535 VM_OBJECT_ASSERT_WLOCKED(m->object);
3536 if (size == 0) /* handle degenerate case */
3540 * If the base is not DEV_BSIZE aligned and the valid
3541 * bit is clear, we have to zero out a portion of the
3544 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3545 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
3546 pmap_zero_page_area(m, frag, base - frag);
3549 * If the ending offset is not DEV_BSIZE aligned and the
3550 * valid bit is clear, we have to zero out a portion of
3553 endoff = base + size;
3554 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3555 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
3556 pmap_zero_page_area(m, endoff,
3557 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3560 * Assert that no previously invalid block that is now being validated
3563 KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
3564 ("vm_page_set_valid_range: page %p is dirty", m));
3567 * Set valid bits inclusive of any overlap.
3569 m->valid |= vm_page_bits(base, size);
3573 * Clear the given bits from the specified page's dirty field.
3575 static __inline void
3576 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
3579 #if PAGE_SIZE < 16384
3584 * If the object is locked and the page is neither exclusive busy nor
3585 * write mapped, then the page's dirty field cannot possibly be
3586 * set by a concurrent pmap operation.
3588 VM_OBJECT_ASSERT_WLOCKED(m->object);
3589 if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
3590 m->dirty &= ~pagebits;
3593 * The pmap layer can call vm_page_dirty() without
3594 * holding a distinguished lock. The combination of
3595 * the object's lock and an atomic operation suffice
3596 * to guarantee consistency of the page dirty field.
3598 * For PAGE_SIZE == 32768 case, compiler already
3599 * properly aligns the dirty field, so no forcible
3600 * alignment is needed. Only require existence of
3601 * atomic_clear_64 when page size is 32768.
3603 addr = (uintptr_t)&m->dirty;
3604 #if PAGE_SIZE == 32768
3605 atomic_clear_64((uint64_t *)addr, pagebits);
3606 #elif PAGE_SIZE == 16384
3607 atomic_clear_32((uint32_t *)addr, pagebits);
3608 #else /* PAGE_SIZE <= 8192 */
3610 * Use a trick to perform a 32-bit atomic on the
3611 * containing aligned word, to not depend on the existence
3612 * of atomic_clear_{8, 16}.
3614 shift = addr & (sizeof(uint32_t) - 1);
3615 #if BYTE_ORDER == BIG_ENDIAN
3616 shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
3620 addr &= ~(sizeof(uint32_t) - 1);
3621 atomic_clear_32((uint32_t *)addr, pagebits << shift);
3622 #endif /* PAGE_SIZE */
3627 * vm_page_set_validclean:
3629 * Sets portions of a page valid and clean. The arguments are expected
3630 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
3631 * of any partial chunks touched by the range. The invalid portion of
3632 * such chunks will be zero'd.
3634 * (base + size) must be less then or equal to PAGE_SIZE.
3637 vm_page_set_validclean(vm_page_t m, int base, int size)
3639 vm_page_bits_t oldvalid, pagebits;
3642 VM_OBJECT_ASSERT_WLOCKED(m->object);
3643 if (size == 0) /* handle degenerate case */
3647 * If the base is not DEV_BSIZE aligned and the valid
3648 * bit is clear, we have to zero out a portion of the
3651 if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
3652 (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
3653 pmap_zero_page_area(m, frag, base - frag);
3656 * If the ending offset is not DEV_BSIZE aligned and the
3657 * valid bit is clear, we have to zero out a portion of
3660 endoff = base + size;
3661 if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
3662 (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
3663 pmap_zero_page_area(m, endoff,
3664 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
3667 * Set valid, clear dirty bits. If validating the entire
3668 * page we can safely clear the pmap modify bit. We also
3669 * use this opportunity to clear the VPO_NOSYNC flag. If a process
3670 * takes a write fault on a MAP_NOSYNC memory area the flag will
3673 * We set valid bits inclusive of any overlap, but we can only
3674 * clear dirty bits for DEV_BSIZE chunks that are fully within
3677 oldvalid = m->valid;
3678 pagebits = vm_page_bits(base, size);
3679 m->valid |= pagebits;
3681 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
3682 frag = DEV_BSIZE - frag;
3688 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
3690 if (base == 0 && size == PAGE_SIZE) {
3692 * The page can only be modified within the pmap if it is
3693 * mapped, and it can only be mapped if it was previously
3696 if (oldvalid == VM_PAGE_BITS_ALL)
3698 * Perform the pmap_clear_modify() first. Otherwise,
3699 * a concurrent pmap operation, such as
3700 * pmap_protect(), could clear a modification in the
3701 * pmap and set the dirty field on the page before
3702 * pmap_clear_modify() had begun and after the dirty
3703 * field was cleared here.
3705 pmap_clear_modify(m);
3707 m->oflags &= ~VPO_NOSYNC;
3708 } else if (oldvalid != VM_PAGE_BITS_ALL)
3709 m->dirty &= ~pagebits;
3711 vm_page_clear_dirty_mask(m, pagebits);
3715 vm_page_clear_dirty(vm_page_t m, int base, int size)
3718 vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
3722 * vm_page_set_invalid:
3724 * Invalidates DEV_BSIZE'd chunks within a page. Both the
3725 * valid and dirty bits for the effected areas are cleared.
3728 vm_page_set_invalid(vm_page_t m, int base, int size)
3730 vm_page_bits_t bits;
3734 VM_OBJECT_ASSERT_WLOCKED(object);
3735 if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
3736 size >= object->un_pager.vnp.vnp_size)
3737 bits = VM_PAGE_BITS_ALL;
3739 bits = vm_page_bits(base, size);
3740 if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL &&
3743 KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
3744 !pmap_page_is_mapped(m),
3745 ("vm_page_set_invalid: page %p is mapped", m));
3751 * vm_page_zero_invalid()
3753 * The kernel assumes that the invalid portions of a page contain
3754 * garbage, but such pages can be mapped into memory by user code.
3755 * When this occurs, we must zero out the non-valid portions of the
3756 * page so user code sees what it expects.
3758 * Pages are most often semi-valid when the end of a file is mapped
3759 * into memory and the file's size is not page aligned.
3762 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
3767 VM_OBJECT_ASSERT_WLOCKED(m->object);
3769 * Scan the valid bits looking for invalid sections that
3770 * must be zeroed. Invalid sub-DEV_BSIZE'd areas ( where the
3771 * valid bit may be set ) have already been zeroed by
3772 * vm_page_set_validclean().
3774 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
3775 if (i == (PAGE_SIZE / DEV_BSIZE) ||
3776 (m->valid & ((vm_page_bits_t)1 << i))) {
3778 pmap_zero_page_area(m,
3779 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
3786 * setvalid is TRUE when we can safely set the zero'd areas
3787 * as being valid. We can do this if there are no cache consistancy
3788 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
3791 m->valid = VM_PAGE_BITS_ALL;
3797 * Is (partial) page valid? Note that the case where size == 0
3798 * will return FALSE in the degenerate case where the page is
3799 * entirely invalid, and TRUE otherwise.
3802 vm_page_is_valid(vm_page_t m, int base, int size)
3804 vm_page_bits_t bits;
3806 VM_OBJECT_ASSERT_LOCKED(m->object);
3807 bits = vm_page_bits(base, size);
3808 return (m->valid != 0 && (m->valid & bits) == bits);
3812 * Returns true if all of the specified predicates are true for the entire
3813 * (super)page and false otherwise.
3816 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m)
3822 VM_OBJECT_ASSERT_LOCKED(object);
3823 npages = atop(pagesizes[m->psind]);
3826 * The physically contiguous pages that make up a superpage, i.e., a
3827 * page with a page size index ("psind") greater than zero, will
3828 * occupy adjacent entries in vm_page_array[].
3830 for (i = 0; i < npages; i++) {
3831 /* Always test object consistency, including "skip_m". */
3832 if (m[i].object != object)
3834 if (&m[i] == skip_m)
3836 if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i]))
3838 if ((flags & PS_ALL_DIRTY) != 0) {
3840 * Calling vm_page_test_dirty() or pmap_is_modified()
3841 * might stop this case from spuriously returning
3842 * "false". However, that would require a write lock
3843 * on the object containing "m[i]".
3845 if (m[i].dirty != VM_PAGE_BITS_ALL)
3848 if ((flags & PS_ALL_VALID) != 0 &&
3849 m[i].valid != VM_PAGE_BITS_ALL)
3856 * Set the page's dirty bits if the page is modified.
3859 vm_page_test_dirty(vm_page_t m)
3862 VM_OBJECT_ASSERT_WLOCKED(m->object);
3863 if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
3868 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
3871 mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
3875 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
3878 mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
3882 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
3885 return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
3888 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
3890 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
3893 vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
3897 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
3900 mtx_assert_(vm_page_lockptr(m), a, file, line);
3906 vm_page_object_lock_assert(vm_page_t m)
3910 * Certain of the page's fields may only be modified by the
3911 * holder of the containing object's lock or the exclusive busy.
3912 * holder. Unfortunately, the holder of the write busy is
3913 * not recorded, and thus cannot be checked here.
3915 if (m->object != NULL && !vm_page_xbusied(m))
3916 VM_OBJECT_ASSERT_WLOCKED(m->object);
3920 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits)
3923 if ((bits & PGA_WRITEABLE) == 0)
3927 * The PGA_WRITEABLE flag can only be set if the page is
3928 * managed, is exclusively busied or the object is locked.
3929 * Currently, this flag is only set by pmap_enter().
3931 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3932 ("PGA_WRITEABLE on unmanaged page"));
3933 if (!vm_page_xbusied(m))
3934 VM_OBJECT_ASSERT_LOCKED(m->object);
3938 #include "opt_ddb.h"
3940 #include <sys/kernel.h>
3942 #include <ddb/ddb.h>
3944 DB_SHOW_COMMAND(page, vm_page_print_page_info)
3947 db_printf("vm_cnt.v_free_count: %d\n", vm_cnt.v_free_count);
3948 db_printf("vm_cnt.v_inactive_count: %d\n", vm_cnt.v_inactive_count);
3949 db_printf("vm_cnt.v_active_count: %d\n", vm_cnt.v_active_count);
3950 db_printf("vm_cnt.v_laundry_count: %d\n", vm_cnt.v_laundry_count);
3951 db_printf("vm_cnt.v_wire_count: %d\n", vm_cnt.v_wire_count);
3952 db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
3953 db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
3954 db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
3955 db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
3958 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
3962 db_printf("pq_free %d\n", vm_cnt.v_free_count);
3963 for (dom = 0; dom < vm_ndomains; dom++) {
3965 "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
3967 vm_dom[dom].vmd_page_count,
3968 vm_dom[dom].vmd_free_count,
3969 vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
3970 vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
3971 vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
3972 vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
3976 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
3982 db_printf("show pginfo addr\n");
3986 phys = strchr(modif, 'p') != NULL;
3988 m = PHYS_TO_VM_PAGE(addr);
3990 m = (vm_page_t)addr;
3992 "page %p obj %p pidx 0x%jx phys 0x%jx q %d hold %d wire %d\n"
3993 " af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
3994 m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
3995 m->queue, m->hold_count, m->wire_count, m->aflags, m->oflags,
3996 m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);