xref: /freebsd/sys/vm/vm_page.c (revision 20bd59416dcacbd2b776fe49dfa193900f303287)
1 /*-
2  * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
3  *
4  * Copyright (c) 1991 Regents of the University of California.
5  * All rights reserved.
6  * Copyright (c) 1998 Matthew Dillon.  All Rights Reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * The Mach Operating System project at Carnegie-Mellon University.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
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.
22  *
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
33  * SUCH DAMAGE.
34  *
35  *	from: @(#)vm_page.c	7.4 (Berkeley) 5/7/91
36  */
37 
38 /*-
39  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40  * All rights reserved.
41  *
42  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
43  *
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.
49  *
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.
53  *
54  * Carnegie Mellon requests users of this software to return to
55  *
56  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
57  *  School of Computer Science
58  *  Carnegie Mellon University
59  *  Pittsburgh PA 15213-3890
60  *
61  * any improvements or extensions that they make and grant Carnegie the
62  * rights to redistribute these changes.
63  */
64 
65 /*
66  *	Resident memory management module.
67  */
68 
69 #include <sys/cdefs.h>
70 __FBSDID("$FreeBSD$");
71 
72 #include "opt_vm.h"
73 
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/counter.h>
77 #include <sys/domainset.h>
78 #include <sys/kernel.h>
79 #include <sys/limits.h>
80 #include <sys/linker.h>
81 #include <sys/lock.h>
82 #include <sys/malloc.h>
83 #include <sys/mman.h>
84 #include <sys/msgbuf.h>
85 #include <sys/mutex.h>
86 #include <sys/proc.h>
87 #include <sys/rwlock.h>
88 #include <sys/sleepqueue.h>
89 #include <sys/sbuf.h>
90 #include <sys/sched.h>
91 #include <sys/smp.h>
92 #include <sys/sysctl.h>
93 #include <sys/vmmeter.h>
94 #include <sys/vnode.h>
95 
96 #include <vm/vm.h>
97 #include <vm/pmap.h>
98 #include <vm/vm_param.h>
99 #include <vm/vm_domainset.h>
100 #include <vm/vm_kern.h>
101 #include <vm/vm_map.h>
102 #include <vm/vm_object.h>
103 #include <vm/vm_page.h>
104 #include <vm/vm_pageout.h>
105 #include <vm/vm_phys.h>
106 #include <vm/vm_pagequeue.h>
107 #include <vm/vm_pager.h>
108 #include <vm/vm_radix.h>
109 #include <vm/vm_reserv.h>
110 #include <vm/vm_extern.h>
111 #include <vm/uma.h>
112 #include <vm/uma_int.h>
113 
114 #include <machine/md_var.h>
115 
116 extern int	uma_startup_count(int);
117 extern void	uma_startup(void *, int);
118 extern int	vmem_startup_count(void);
119 
120 struct vm_domain vm_dom[MAXMEMDOM];
121 
122 DPCPU_DEFINE_STATIC(struct vm_batchqueue, pqbatch[MAXMEMDOM][PQ_COUNT]);
123 
124 struct mtx_padalign __exclusive_cache_line pa_lock[PA_LOCK_COUNT];
125 
126 struct mtx_padalign __exclusive_cache_line vm_domainset_lock;
127 /* The following fields are protected by the domainset lock. */
128 domainset_t __exclusive_cache_line vm_min_domains;
129 domainset_t __exclusive_cache_line vm_severe_domains;
130 static int vm_min_waiters;
131 static int vm_severe_waiters;
132 static int vm_pageproc_waiters;
133 
134 static SYSCTL_NODE(_vm_stats, OID_AUTO, page, CTLFLAG_RD, 0,
135     "VM page statistics");
136 
137 static counter_u64_t queue_ops = EARLY_COUNTER;
138 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_ops,
139     CTLFLAG_RD, &queue_ops,
140     "Number of batched queue operations");
141 
142 static counter_u64_t queue_nops = EARLY_COUNTER;
143 SYSCTL_COUNTER_U64(_vm_stats_page, OID_AUTO, queue_nops,
144     CTLFLAG_RD, &queue_nops,
145     "Number of batched queue operations with no effects");
146 
147 static void
148 counter_startup(void)
149 {
150 
151 	queue_ops = counter_u64_alloc(M_WAITOK);
152 	queue_nops = counter_u64_alloc(M_WAITOK);
153 }
154 SYSINIT(page_counters, SI_SUB_CPU, SI_ORDER_ANY, counter_startup, NULL);
155 
156 /*
157  * bogus page -- for I/O to/from partially complete buffers,
158  * or for paging into sparsely invalid regions.
159  */
160 vm_page_t bogus_page;
161 
162 vm_page_t vm_page_array;
163 long vm_page_array_size;
164 long first_page;
165 
166 static int boot_pages;
167 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
168     &boot_pages, 0,
169     "number of pages allocated for bootstrapping the VM system");
170 
171 static int pa_tryrelock_restart;
172 SYSCTL_INT(_vm, OID_AUTO, tryrelock_restart, CTLFLAG_RD,
173     &pa_tryrelock_restart, 0, "Number of tryrelock restarts");
174 
175 static TAILQ_HEAD(, vm_page) blacklist_head;
176 static int sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS);
177 SYSCTL_PROC(_vm, OID_AUTO, page_blacklist, CTLTYPE_STRING | CTLFLAG_RD |
178     CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_page_blacklist, "A", "Blacklist pages");
179 
180 static uma_zone_t fakepg_zone;
181 
182 static void vm_page_alloc_check(vm_page_t m);
183 static void vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits);
184 static void vm_page_dequeue_complete(vm_page_t m);
185 static void vm_page_enqueue(vm_page_t m, uint8_t queue);
186 static void vm_page_init(void *dummy);
187 static int vm_page_insert_after(vm_page_t m, vm_object_t object,
188     vm_pindex_t pindex, vm_page_t mpred);
189 static void vm_page_insert_radixdone(vm_page_t m, vm_object_t object,
190     vm_page_t mpred);
191 static void vm_page_mvqueue(vm_page_t m, uint8_t queue);
192 static int vm_page_reclaim_run(int req_class, int domain, u_long npages,
193     vm_page_t m_run, vm_paddr_t high);
194 static int vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object,
195     int req);
196 static int vm_page_zone_import(void *arg, void **store, int cnt, int domain,
197     int flags);
198 static void vm_page_zone_release(void *arg, void **store, int cnt);
199 
200 SYSINIT(vm_page, SI_SUB_VM, SI_ORDER_SECOND, vm_page_init, NULL);
201 
202 static void
203 vm_page_init(void *dummy)
204 {
205 
206 	fakepg_zone = uma_zcreate("fakepg", sizeof(struct vm_page), NULL, NULL,
207 	    NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE | UMA_ZONE_VM);
208 	bogus_page = vm_page_alloc(NULL, 0, VM_ALLOC_NOOBJ |
209 	    VM_ALLOC_NORMAL | VM_ALLOC_WIRED);
210 }
211 
212 /*
213  * The cache page zone is initialized later since we need to be able to allocate
214  * pages before UMA is fully initialized.
215  */
216 static void
217 vm_page_init_cache_zones(void *dummy __unused)
218 {
219 	struct vm_domain *vmd;
220 	struct vm_pgcache *pgcache;
221 	int domain, pool;
222 
223 	for (domain = 0; domain < vm_ndomains; domain++) {
224 		vmd = VM_DOMAIN(domain);
225 
226 		/*
227 		 * Don't allow the page caches to take up more than .25% of
228 		 * memory.
229 		 */
230 		if (vmd->vmd_page_count / 400 < 256 * mp_ncpus * VM_NFREEPOOL)
231 			continue;
232 		for (pool = 0; pool < VM_NFREEPOOL; pool++) {
233 			pgcache = &vmd->vmd_pgcache[pool];
234 			pgcache->domain = domain;
235 			pgcache->pool = pool;
236 			pgcache->zone = uma_zcache_create("vm pgcache",
237 			    sizeof(struct vm_page), NULL, NULL, NULL, NULL,
238 			    vm_page_zone_import, vm_page_zone_release, pgcache,
239 			    UMA_ZONE_MAXBUCKET | UMA_ZONE_VM);
240 			(void)uma_zone_set_maxcache(pgcache->zone, 0);
241 		}
242 	}
243 }
244 SYSINIT(vm_page2, SI_SUB_VM_CONF, SI_ORDER_ANY, vm_page_init_cache_zones, NULL);
245 
246 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
247 #if PAGE_SIZE == 32768
248 #ifdef CTASSERT
249 CTASSERT(sizeof(u_long) >= 8);
250 #endif
251 #endif
252 
253 /*
254  * Try to acquire a physical address lock while a pmap is locked.  If we
255  * fail to trylock we unlock and lock the pmap directly and cache the
256  * locked pa in *locked.  The caller should then restart their loop in case
257  * the virtual to physical mapping has changed.
258  */
259 int
260 vm_page_pa_tryrelock(pmap_t pmap, vm_paddr_t pa, vm_paddr_t *locked)
261 {
262 	vm_paddr_t lockpa;
263 
264 	lockpa = *locked;
265 	*locked = pa;
266 	if (lockpa) {
267 		PA_LOCK_ASSERT(lockpa, MA_OWNED);
268 		if (PA_LOCKPTR(pa) == PA_LOCKPTR(lockpa))
269 			return (0);
270 		PA_UNLOCK(lockpa);
271 	}
272 	if (PA_TRYLOCK(pa))
273 		return (0);
274 	PMAP_UNLOCK(pmap);
275 	atomic_add_int(&pa_tryrelock_restart, 1);
276 	PA_LOCK(pa);
277 	PMAP_LOCK(pmap);
278 	return (EAGAIN);
279 }
280 
281 /*
282  *	vm_set_page_size:
283  *
284  *	Sets the page size, perhaps based upon the memory
285  *	size.  Must be called before any use of page-size
286  *	dependent functions.
287  */
288 void
289 vm_set_page_size(void)
290 {
291 	if (vm_cnt.v_page_size == 0)
292 		vm_cnt.v_page_size = PAGE_SIZE;
293 	if (((vm_cnt.v_page_size - 1) & vm_cnt.v_page_size) != 0)
294 		panic("vm_set_page_size: page size not a power of two");
295 }
296 
297 /*
298  *	vm_page_blacklist_next:
299  *
300  *	Find the next entry in the provided string of blacklist
301  *	addresses.  Entries are separated by space, comma, or newline.
302  *	If an invalid integer is encountered then the rest of the
303  *	string is skipped.  Updates the list pointer to the next
304  *	character, or NULL if the string is exhausted or invalid.
305  */
306 static vm_paddr_t
307 vm_page_blacklist_next(char **list, char *end)
308 {
309 	vm_paddr_t bad;
310 	char *cp, *pos;
311 
312 	if (list == NULL || *list == NULL)
313 		return (0);
314 	if (**list =='\0') {
315 		*list = NULL;
316 		return (0);
317 	}
318 
319 	/*
320 	 * If there's no end pointer then the buffer is coming from
321 	 * the kenv and we know it's null-terminated.
322 	 */
323 	if (end == NULL)
324 		end = *list + strlen(*list);
325 
326 	/* Ensure that strtoq() won't walk off the end */
327 	if (*end != '\0') {
328 		if (*end == '\n' || *end == ' ' || *end  == ',')
329 			*end = '\0';
330 		else {
331 			printf("Blacklist not terminated, skipping\n");
332 			*list = NULL;
333 			return (0);
334 		}
335 	}
336 
337 	for (pos = *list; *pos != '\0'; pos = cp) {
338 		bad = strtoq(pos, &cp, 0);
339 		if (*cp == '\0' || *cp == ' ' || *cp == ',' || *cp == '\n') {
340 			if (bad == 0) {
341 				if (++cp < end)
342 					continue;
343 				else
344 					break;
345 			}
346 		} else
347 			break;
348 		if (*cp == '\0' || ++cp >= end)
349 			*list = NULL;
350 		else
351 			*list = cp;
352 		return (trunc_page(bad));
353 	}
354 	printf("Garbage in RAM blacklist, skipping\n");
355 	*list = NULL;
356 	return (0);
357 }
358 
359 bool
360 vm_page_blacklist_add(vm_paddr_t pa, bool verbose)
361 {
362 	struct vm_domain *vmd;
363 	vm_page_t m;
364 	int ret;
365 
366 	m = vm_phys_paddr_to_vm_page(pa);
367 	if (m == NULL)
368 		return (true); /* page does not exist, no failure */
369 
370 	vmd = vm_pagequeue_domain(m);
371 	vm_domain_free_lock(vmd);
372 	ret = vm_phys_unfree_page(m);
373 	vm_domain_free_unlock(vmd);
374 	if (ret != 0) {
375 		vm_domain_freecnt_inc(vmd, -1);
376 		TAILQ_INSERT_TAIL(&blacklist_head, m, listq);
377 		if (verbose)
378 			printf("Skipping page with pa 0x%jx\n", (uintmax_t)pa);
379 	}
380 	return (ret);
381 }
382 
383 /*
384  *	vm_page_blacklist_check:
385  *
386  *	Iterate through the provided string of blacklist addresses, pulling
387  *	each entry out of the physical allocator free list and putting it
388  *	onto a list for reporting via the vm.page_blacklist sysctl.
389  */
390 static void
391 vm_page_blacklist_check(char *list, char *end)
392 {
393 	vm_paddr_t pa;
394 	char *next;
395 
396 	next = list;
397 	while (next != NULL) {
398 		if ((pa = vm_page_blacklist_next(&next, end)) == 0)
399 			continue;
400 		vm_page_blacklist_add(pa, bootverbose);
401 	}
402 }
403 
404 /*
405  *	vm_page_blacklist_load:
406  *
407  *	Search for a special module named "ram_blacklist".  It'll be a
408  *	plain text file provided by the user via the loader directive
409  *	of the same name.
410  */
411 static void
412 vm_page_blacklist_load(char **list, char **end)
413 {
414 	void *mod;
415 	u_char *ptr;
416 	u_int len;
417 
418 	mod = NULL;
419 	ptr = NULL;
420 
421 	mod = preload_search_by_type("ram_blacklist");
422 	if (mod != NULL) {
423 		ptr = preload_fetch_addr(mod);
424 		len = preload_fetch_size(mod);
425         }
426 	*list = ptr;
427 	if (ptr != NULL)
428 		*end = ptr + len;
429 	else
430 		*end = NULL;
431 	return;
432 }
433 
434 static int
435 sysctl_vm_page_blacklist(SYSCTL_HANDLER_ARGS)
436 {
437 	vm_page_t m;
438 	struct sbuf sbuf;
439 	int error, first;
440 
441 	first = 1;
442 	error = sysctl_wire_old_buffer(req, 0);
443 	if (error != 0)
444 		return (error);
445 	sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
446 	TAILQ_FOREACH(m, &blacklist_head, listq) {
447 		sbuf_printf(&sbuf, "%s%#jx", first ? "" : ",",
448 		    (uintmax_t)m->phys_addr);
449 		first = 0;
450 	}
451 	error = sbuf_finish(&sbuf);
452 	sbuf_delete(&sbuf);
453 	return (error);
454 }
455 
456 /*
457  * Initialize a dummy page for use in scans of the specified paging queue.
458  * In principle, this function only needs to set the flag PG_MARKER.
459  * Nonetheless, it write busies the page as a safety precaution.
460  */
461 static void
462 vm_page_init_marker(vm_page_t marker, int queue, uint8_t aflags)
463 {
464 
465 	bzero(marker, sizeof(*marker));
466 	marker->flags = PG_MARKER;
467 	marker->aflags = aflags;
468 	marker->busy_lock = VPB_SINGLE_EXCLUSIVER;
469 	marker->queue = queue;
470 }
471 
472 static void
473 vm_page_domain_init(int domain)
474 {
475 	struct vm_domain *vmd;
476 	struct vm_pagequeue *pq;
477 	int i;
478 
479 	vmd = VM_DOMAIN(domain);
480 	bzero(vmd, sizeof(*vmd));
481 	*__DECONST(char **, &vmd->vmd_pagequeues[PQ_INACTIVE].pq_name) =
482 	    "vm inactive pagequeue";
483 	*__DECONST(char **, &vmd->vmd_pagequeues[PQ_ACTIVE].pq_name) =
484 	    "vm active pagequeue";
485 	*__DECONST(char **, &vmd->vmd_pagequeues[PQ_LAUNDRY].pq_name) =
486 	    "vm laundry pagequeue";
487 	*__DECONST(char **, &vmd->vmd_pagequeues[PQ_UNSWAPPABLE].pq_name) =
488 	    "vm unswappable pagequeue";
489 	vmd->vmd_domain = domain;
490 	vmd->vmd_page_count = 0;
491 	vmd->vmd_free_count = 0;
492 	vmd->vmd_segs = 0;
493 	vmd->vmd_oom = FALSE;
494 	for (i = 0; i < PQ_COUNT; i++) {
495 		pq = &vmd->vmd_pagequeues[i];
496 		TAILQ_INIT(&pq->pq_pl);
497 		mtx_init(&pq->pq_mutex, pq->pq_name, "vm pagequeue",
498 		    MTX_DEF | MTX_DUPOK);
499 		pq->pq_pdpages = 0;
500 		vm_page_init_marker(&vmd->vmd_markers[i], i, 0);
501 	}
502 	mtx_init(&vmd->vmd_free_mtx, "vm page free queue", NULL, MTX_DEF);
503 	mtx_init(&vmd->vmd_pageout_mtx, "vm pageout lock", NULL, MTX_DEF);
504 	snprintf(vmd->vmd_name, sizeof(vmd->vmd_name), "%d", domain);
505 
506 	/*
507 	 * inacthead is used to provide FIFO ordering for LRU-bypassing
508 	 * insertions.
509 	 */
510 	vm_page_init_marker(&vmd->vmd_inacthead, PQ_INACTIVE, PGA_ENQUEUED);
511 	TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_INACTIVE].pq_pl,
512 	    &vmd->vmd_inacthead, plinks.q);
513 
514 	/*
515 	 * The clock pages are used to implement active queue scanning without
516 	 * requeues.  Scans start at clock[0], which is advanced after the scan
517 	 * ends.  When the two clock hands meet, they are reset and scanning
518 	 * resumes from the head of the queue.
519 	 */
520 	vm_page_init_marker(&vmd->vmd_clock[0], PQ_ACTIVE, PGA_ENQUEUED);
521 	vm_page_init_marker(&vmd->vmd_clock[1], PQ_ACTIVE, PGA_ENQUEUED);
522 	TAILQ_INSERT_HEAD(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl,
523 	    &vmd->vmd_clock[0], plinks.q);
524 	TAILQ_INSERT_TAIL(&vmd->vmd_pagequeues[PQ_ACTIVE].pq_pl,
525 	    &vmd->vmd_clock[1], plinks.q);
526 }
527 
528 /*
529  * Initialize a physical page in preparation for adding it to the free
530  * lists.
531  */
532 static void
533 vm_page_init_page(vm_page_t m, vm_paddr_t pa, int segind)
534 {
535 
536 	m->object = NULL;
537 	m->ref_count = 0;
538 	m->busy_lock = VPB_UNBUSIED;
539 	m->flags = m->aflags = 0;
540 	m->phys_addr = pa;
541 	m->queue = PQ_NONE;
542 	m->psind = 0;
543 	m->segind = segind;
544 	m->order = VM_NFREEORDER;
545 	m->pool = VM_FREEPOOL_DEFAULT;
546 	m->valid = m->dirty = 0;
547 	pmap_page_init(m);
548 }
549 
550 #ifndef PMAP_HAS_PAGE_ARRAY
551 static vm_paddr_t
552 vm_page_array_alloc(vm_offset_t *vaddr, vm_paddr_t end, vm_paddr_t page_range)
553 {
554 	vm_paddr_t new_end;
555 
556 	/*
557 	 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
558 	 * However, because this page is allocated from KVM, out-of-bounds
559 	 * accesses using the direct map will not be trapped.
560 	 */
561 	*vaddr += PAGE_SIZE;
562 
563 	/*
564 	 * Allocate physical memory for the page structures, and map it.
565 	 */
566 	new_end = trunc_page(end - page_range * sizeof(struct vm_page));
567 	vm_page_array = (vm_page_t)pmap_map(vaddr, new_end, end,
568 	    VM_PROT_READ | VM_PROT_WRITE);
569 	vm_page_array_size = page_range;
570 
571 	return (new_end);
572 }
573 #endif
574 
575 /*
576  *	vm_page_startup:
577  *
578  *	Initializes the resident memory module.  Allocates physical memory for
579  *	bootstrapping UMA and some data structures that are used to manage
580  *	physical pages.  Initializes these structures, and populates the free
581  *	page queues.
582  */
583 vm_offset_t
584 vm_page_startup(vm_offset_t vaddr)
585 {
586 	struct vm_phys_seg *seg;
587 	vm_page_t m;
588 	char *list, *listend;
589 	vm_offset_t mapped;
590 	vm_paddr_t end, high_avail, low_avail, new_end, page_range, size;
591 	vm_paddr_t last_pa, pa;
592 	u_long pagecount;
593 	int biggestone, i, segind;
594 #ifdef WITNESS
595 	int witness_size;
596 #endif
597 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
598 	long ii;
599 #endif
600 
601 	vaddr = round_page(vaddr);
602 
603 	vm_phys_early_startup();
604 	biggestone = vm_phys_avail_largest();
605 	end = phys_avail[biggestone+1];
606 
607 	/*
608 	 * Initialize the page and queue locks.
609 	 */
610 	mtx_init(&vm_domainset_lock, "vm domainset lock", NULL, MTX_DEF);
611 	for (i = 0; i < PA_LOCK_COUNT; i++)
612 		mtx_init(&pa_lock[i], "vm page", NULL, MTX_DEF);
613 	for (i = 0; i < vm_ndomains; i++)
614 		vm_page_domain_init(i);
615 
616 	/*
617 	 * Allocate memory for use when boot strapping the kernel memory
618 	 * allocator.  Tell UMA how many zones we are going to create
619 	 * before going fully functional.  UMA will add its zones.
620 	 *
621 	 * VM startup zones: vmem, vmem_btag, VM OBJECT, RADIX NODE, MAP,
622 	 * KMAP ENTRY, MAP ENTRY, VMSPACE.
623 	 */
624 	boot_pages = uma_startup_count(8);
625 
626 #ifndef UMA_MD_SMALL_ALLOC
627 	/* vmem_startup() calls uma_prealloc(). */
628 	boot_pages += vmem_startup_count();
629 	/* vm_map_startup() calls uma_prealloc(). */
630 	boot_pages += howmany(MAX_KMAP,
631 	    UMA_SLAB_SPACE / sizeof(struct vm_map));
632 
633 	/*
634 	 * Before going fully functional kmem_init() does allocation
635 	 * from "KMAP ENTRY" and vmem_create() does allocation from "vmem".
636 	 */
637 	boot_pages += 2;
638 #endif
639 	/*
640 	 * CTFLAG_RDTUN doesn't work during the early boot process, so we must
641 	 * manually fetch the value.
642 	 */
643 	TUNABLE_INT_FETCH("vm.boot_pages", &boot_pages);
644 	new_end = end - (boot_pages * UMA_SLAB_SIZE);
645 	new_end = trunc_page(new_end);
646 	mapped = pmap_map(&vaddr, new_end, end,
647 	    VM_PROT_READ | VM_PROT_WRITE);
648 	bzero((void *)mapped, end - new_end);
649 	uma_startup((void *)mapped, boot_pages);
650 
651 #ifdef WITNESS
652 	witness_size = round_page(witness_startup_count());
653 	new_end -= witness_size;
654 	mapped = pmap_map(&vaddr, new_end, new_end + witness_size,
655 	    VM_PROT_READ | VM_PROT_WRITE);
656 	bzero((void *)mapped, witness_size);
657 	witness_startup((void *)mapped);
658 #endif
659 
660 #if defined(__aarch64__) || defined(__amd64__) || defined(__arm__) || \
661     defined(__i386__) || defined(__mips__) || defined(__riscv)
662 	/*
663 	 * Allocate a bitmap to indicate that a random physical page
664 	 * needs to be included in a minidump.
665 	 *
666 	 * The amd64 port needs this to indicate which direct map pages
667 	 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
668 	 *
669 	 * However, i386 still needs this workspace internally within the
670 	 * minidump code.  In theory, they are not needed on i386, but are
671 	 * included should the sf_buf code decide to use them.
672 	 */
673 	last_pa = 0;
674 	for (i = 0; dump_avail[i + 1] != 0; i += 2)
675 		if (dump_avail[i + 1] > last_pa)
676 			last_pa = dump_avail[i + 1];
677 	page_range = last_pa / PAGE_SIZE;
678 	vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
679 	new_end -= vm_page_dump_size;
680 	vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
681 	    new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
682 	bzero((void *)vm_page_dump, vm_page_dump_size);
683 #else
684 	(void)last_pa;
685 #endif
686 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
687     defined(__riscv)
688 	/*
689 	 * Include the UMA bootstrap pages, witness pages and vm_page_dump
690 	 * in a crash dump.  When pmap_map() uses the direct map, they are
691 	 * not automatically included.
692 	 */
693 	for (pa = new_end; pa < end; pa += PAGE_SIZE)
694 		dump_add_page(pa);
695 #endif
696 	phys_avail[biggestone + 1] = new_end;
697 #ifdef __amd64__
698 	/*
699 	 * Request that the physical pages underlying the message buffer be
700 	 * included in a crash dump.  Since the message buffer is accessed
701 	 * through the direct map, they are not automatically included.
702 	 */
703 	pa = DMAP_TO_PHYS((vm_offset_t)msgbufp->msg_ptr);
704 	last_pa = pa + round_page(msgbufsize);
705 	while (pa < last_pa) {
706 		dump_add_page(pa);
707 		pa += PAGE_SIZE;
708 	}
709 #endif
710 	/*
711 	 * Compute the number of pages of memory that will be available for
712 	 * use, taking into account the overhead of a page structure per page.
713 	 * In other words, solve
714 	 *	"available physical memory" - round_page(page_range *
715 	 *	    sizeof(struct vm_page)) = page_range * PAGE_SIZE
716 	 * for page_range.
717 	 */
718 	low_avail = phys_avail[0];
719 	high_avail = phys_avail[1];
720 	for (i = 0; i < vm_phys_nsegs; i++) {
721 		if (vm_phys_segs[i].start < low_avail)
722 			low_avail = vm_phys_segs[i].start;
723 		if (vm_phys_segs[i].end > high_avail)
724 			high_avail = vm_phys_segs[i].end;
725 	}
726 	/* Skip the first chunk.  It is already accounted for. */
727 	for (i = 2; phys_avail[i + 1] != 0; i += 2) {
728 		if (phys_avail[i] < low_avail)
729 			low_avail = phys_avail[i];
730 		if (phys_avail[i + 1] > high_avail)
731 			high_avail = phys_avail[i + 1];
732 	}
733 	first_page = low_avail / PAGE_SIZE;
734 #ifdef VM_PHYSSEG_SPARSE
735 	size = 0;
736 	for (i = 0; i < vm_phys_nsegs; i++)
737 		size += vm_phys_segs[i].end - vm_phys_segs[i].start;
738 	for (i = 0; phys_avail[i + 1] != 0; i += 2)
739 		size += phys_avail[i + 1] - phys_avail[i];
740 #elif defined(VM_PHYSSEG_DENSE)
741 	size = high_avail - low_avail;
742 #else
743 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
744 #endif
745 
746 #ifdef PMAP_HAS_PAGE_ARRAY
747 	pmap_page_array_startup(size / PAGE_SIZE);
748 	biggestone = vm_phys_avail_largest();
749 	end = new_end = phys_avail[biggestone + 1];
750 #else
751 #ifdef VM_PHYSSEG_DENSE
752 	/*
753 	 * In the VM_PHYSSEG_DENSE case, the number of pages can account for
754 	 * the overhead of a page structure per page only if vm_page_array is
755 	 * allocated from the last physical memory chunk.  Otherwise, we must
756 	 * allocate page structures representing the physical memory
757 	 * underlying vm_page_array, even though they will not be used.
758 	 */
759 	if (new_end != high_avail)
760 		page_range = size / PAGE_SIZE;
761 	else
762 #endif
763 	{
764 		page_range = size / (PAGE_SIZE + sizeof(struct vm_page));
765 
766 		/*
767 		 * If the partial bytes remaining are large enough for
768 		 * a page (PAGE_SIZE) without a corresponding
769 		 * 'struct vm_page', then new_end will contain an
770 		 * extra page after subtracting the length of the VM
771 		 * page array.  Compensate by subtracting an extra
772 		 * page from new_end.
773 		 */
774 		if (size % (PAGE_SIZE + sizeof(struct vm_page)) >= PAGE_SIZE) {
775 			if (new_end == high_avail)
776 				high_avail -= PAGE_SIZE;
777 			new_end -= PAGE_SIZE;
778 		}
779 	}
780 	end = new_end;
781 	new_end = vm_page_array_alloc(&vaddr, end, page_range);
782 #endif
783 
784 #if VM_NRESERVLEVEL > 0
785 	/*
786 	 * Allocate physical memory for the reservation management system's
787 	 * data structures, and map it.
788 	 */
789 	new_end = vm_reserv_startup(&vaddr, new_end);
790 #endif
791 #if defined(__aarch64__) || defined(__amd64__) || defined(__mips__) || \
792     defined(__riscv)
793 	/*
794 	 * Include vm_page_array and vm_reserv_array in a crash dump.
795 	 */
796 	for (pa = new_end; pa < end; pa += PAGE_SIZE)
797 		dump_add_page(pa);
798 #endif
799 	phys_avail[biggestone + 1] = new_end;
800 
801 	/*
802 	 * Add physical memory segments corresponding to the available
803 	 * physical pages.
804 	 */
805 	for (i = 0; phys_avail[i + 1] != 0; i += 2)
806 		if (vm_phys_avail_size(i) != 0)
807 			vm_phys_add_seg(phys_avail[i], phys_avail[i + 1]);
808 
809 	/*
810 	 * Initialize the physical memory allocator.
811 	 */
812 	vm_phys_init();
813 
814 	/*
815 	 * Initialize the page structures and add every available page to the
816 	 * physical memory allocator's free lists.
817 	 */
818 #if defined(__i386__) && defined(VM_PHYSSEG_DENSE)
819 	for (ii = 0; ii < vm_page_array_size; ii++) {
820 		m = &vm_page_array[ii];
821 		vm_page_init_page(m, (first_page + ii) << PAGE_SHIFT, 0);
822 		m->flags = PG_FICTITIOUS;
823 	}
824 #endif
825 	vm_cnt.v_page_count = 0;
826 	for (segind = 0; segind < vm_phys_nsegs; segind++) {
827 		seg = &vm_phys_segs[segind];
828 		for (m = seg->first_page, pa = seg->start; pa < seg->end;
829 		    m++, pa += PAGE_SIZE)
830 			vm_page_init_page(m, pa, segind);
831 
832 		/*
833 		 * Add the segment to the free lists only if it is covered by
834 		 * one of the ranges in phys_avail.  Because we've added the
835 		 * ranges to the vm_phys_segs array, we can assume that each
836 		 * segment is either entirely contained in one of the ranges,
837 		 * or doesn't overlap any of them.
838 		 */
839 		for (i = 0; phys_avail[i + 1] != 0; i += 2) {
840 			struct vm_domain *vmd;
841 
842 			if (seg->start < phys_avail[i] ||
843 			    seg->end > phys_avail[i + 1])
844 				continue;
845 
846 			m = seg->first_page;
847 			pagecount = (u_long)atop(seg->end - seg->start);
848 
849 			vmd = VM_DOMAIN(seg->domain);
850 			vm_domain_free_lock(vmd);
851 			vm_phys_enqueue_contig(m, pagecount);
852 			vm_domain_free_unlock(vmd);
853 			vm_domain_freecnt_inc(vmd, pagecount);
854 			vm_cnt.v_page_count += (u_int)pagecount;
855 
856 			vmd = VM_DOMAIN(seg->domain);
857 			vmd->vmd_page_count += (u_int)pagecount;
858 			vmd->vmd_segs |= 1UL << m->segind;
859 			break;
860 		}
861 	}
862 
863 	/*
864 	 * Remove blacklisted pages from the physical memory allocator.
865 	 */
866 	TAILQ_INIT(&blacklist_head);
867 	vm_page_blacklist_load(&list, &listend);
868 	vm_page_blacklist_check(list, listend);
869 
870 	list = kern_getenv("vm.blacklist");
871 	vm_page_blacklist_check(list, NULL);
872 
873 	freeenv(list);
874 #if VM_NRESERVLEVEL > 0
875 	/*
876 	 * Initialize the reservation management system.
877 	 */
878 	vm_reserv_init();
879 #endif
880 
881 	return (vaddr);
882 }
883 
884 void
885 vm_page_reference(vm_page_t m)
886 {
887 
888 	vm_page_aflag_set(m, PGA_REFERENCED);
889 }
890 
891 /*
892  *	vm_page_busy_acquire:
893  *
894  *	Acquire the busy lock as described by VM_ALLOC_* flags.  Will loop
895  *	and drop the object lock if necessary.
896  */
897 int
898 vm_page_busy_acquire(vm_page_t m, int allocflags)
899 {
900 	vm_object_t obj;
901 	u_int x;
902 	bool locked;
903 
904 	/*
905 	 * The page-specific object must be cached because page
906 	 * identity can change during the sleep, causing the
907 	 * re-lock of a different object.
908 	 * It is assumed that a reference to the object is already
909 	 * held by the callers.
910 	 */
911 	obj = m->object;
912 	for (;;) {
913 		if ((allocflags & VM_ALLOC_SBUSY) == 0) {
914 			if (vm_page_tryxbusy(m))
915 				return (TRUE);
916 		} else {
917 			if (vm_page_trysbusy(m))
918 				return (TRUE);
919 		}
920 		if ((allocflags & VM_ALLOC_NOWAIT) != 0)
921 			return (FALSE);
922 		if (obj != NULL) {
923 			locked = VM_OBJECT_WOWNED(obj);
924 		} else {
925 			MPASS(vm_page_wired(m));
926 			locked = FALSE;
927 		}
928 		sleepq_lock(m);
929 		x = m->busy_lock;
930 		if (x == VPB_UNBUSIED ||
931 		    ((allocflags & VM_ALLOC_SBUSY) != 0 &&
932 		    (x & VPB_BIT_SHARED) != 0) ||
933 		    ((x & VPB_BIT_WAITERS) == 0 &&
934 		    !atomic_cmpset_int(&m->busy_lock, x,
935 		    x | VPB_BIT_WAITERS))) {
936 			sleepq_release(m);
937 			continue;
938 		}
939 		if (locked)
940 			VM_OBJECT_WUNLOCK(obj);
941 		sleepq_add(m, NULL, "vmpba", 0, 0);
942 		sleepq_wait(m, PVM);
943 		if (locked)
944 			VM_OBJECT_WLOCK(obj);
945 		MPASS(m->object == obj || m->object == NULL);
946 		if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
947 			return (FALSE);
948 	}
949 }
950 
951 /*
952  *	vm_page_busy_downgrade:
953  *
954  *	Downgrade an exclusive busy page into a single shared busy page.
955  */
956 void
957 vm_page_busy_downgrade(vm_page_t m)
958 {
959 	u_int x;
960 
961 	vm_page_assert_xbusied(m);
962 
963 	x = m->busy_lock;
964 	for (;;) {
965 		if (atomic_fcmpset_rel_int(&m->busy_lock,
966 		    &x, VPB_SHARERS_WORD(1)))
967 			break;
968 	}
969 	if ((x & VPB_BIT_WAITERS) != 0)
970 		wakeup(m);
971 }
972 
973 /*
974  *	vm_page_sbusied:
975  *
976  *	Return a positive value if the page is shared busied, 0 otherwise.
977  */
978 int
979 vm_page_sbusied(vm_page_t m)
980 {
981 	u_int x;
982 
983 	x = m->busy_lock;
984 	return ((x & VPB_BIT_SHARED) != 0 && x != VPB_UNBUSIED);
985 }
986 
987 /*
988  *	vm_page_sunbusy:
989  *
990  *	Shared unbusy a page.
991  */
992 void
993 vm_page_sunbusy(vm_page_t m)
994 {
995 	u_int x;
996 
997 	vm_page_assert_sbusied(m);
998 
999 	x = m->busy_lock;
1000 	for (;;) {
1001 		if (VPB_SHARERS(x) > 1) {
1002 			if (atomic_fcmpset_int(&m->busy_lock, &x,
1003 			    x - VPB_ONE_SHARER))
1004 				break;
1005 			continue;
1006 		}
1007 		KASSERT((x & ~VPB_BIT_WAITERS) == VPB_SHARERS_WORD(1),
1008 		    ("vm_page_sunbusy: invalid lock state"));
1009 		if (!atomic_fcmpset_rel_int(&m->busy_lock, &x, VPB_UNBUSIED))
1010 			continue;
1011 		if ((x & VPB_BIT_WAITERS) == 0)
1012 			break;
1013 		wakeup(m);
1014 		break;
1015 	}
1016 }
1017 
1018 /*
1019  *	vm_page_busy_sleep:
1020  *
1021  *	Sleep if the page is busy, using the page pointer as wchan.
1022  *	This is used to implement the hard-path of busying mechanism.
1023  *
1024  *	If nonshared is true, sleep only if the page is xbusy.
1025  *
1026  *	The object lock must be held on entry and will be released on exit.
1027  */
1028 void
1029 vm_page_busy_sleep(vm_page_t m, const char *wmesg, bool nonshared)
1030 {
1031 	vm_object_t obj;
1032 	u_int x;
1033 
1034 	obj = m->object;
1035 	vm_page_lock_assert(m, MA_NOTOWNED);
1036 	VM_OBJECT_ASSERT_LOCKED(obj);
1037 
1038 	sleepq_lock(m);
1039 	x = m->busy_lock;
1040 	if (x == VPB_UNBUSIED || (nonshared && (x & VPB_BIT_SHARED) != 0) ||
1041 	    ((x & VPB_BIT_WAITERS) == 0 &&
1042 	    !atomic_cmpset_int(&m->busy_lock, x, x | VPB_BIT_WAITERS))) {
1043 		VM_OBJECT_DROP(obj);
1044 		sleepq_release(m);
1045 		return;
1046 	}
1047 	VM_OBJECT_DROP(obj);
1048 	sleepq_add(m, NULL, wmesg, 0, 0);
1049 	sleepq_wait(m, PVM);
1050 }
1051 
1052 /*
1053  *	vm_page_trysbusy:
1054  *
1055  *	Try to shared busy a page.
1056  *	If the operation succeeds 1 is returned otherwise 0.
1057  *	The operation never sleeps.
1058  */
1059 int
1060 vm_page_trysbusy(vm_page_t m)
1061 {
1062 	u_int x;
1063 
1064 	x = m->busy_lock;
1065 	for (;;) {
1066 		if ((x & VPB_BIT_SHARED) == 0)
1067 			return (0);
1068 		if (atomic_fcmpset_acq_int(&m->busy_lock, &x,
1069 		    x + VPB_ONE_SHARER))
1070 			return (1);
1071 	}
1072 }
1073 
1074 /*
1075  *	vm_page_xunbusy_hard:
1076  *
1077  *	Called when unbusy has failed because there is a waiter.
1078  */
1079 void
1080 vm_page_xunbusy_hard(vm_page_t m)
1081 {
1082 
1083 	vm_page_assert_xbusied(m);
1084 
1085 	/*
1086 	 * Wake the waiter.
1087 	 */
1088 	atomic_store_rel_int(&m->busy_lock, VPB_UNBUSIED);
1089 	wakeup(m);
1090 }
1091 
1092 /*
1093  * Avoid releasing and reacquiring the same page lock.
1094  */
1095 void
1096 vm_page_change_lock(vm_page_t m, struct mtx **mtx)
1097 {
1098 	struct mtx *mtx1;
1099 
1100 	mtx1 = vm_page_lockptr(m);
1101 	if (*mtx == mtx1)
1102 		return;
1103 	if (*mtx != NULL)
1104 		mtx_unlock(*mtx);
1105 	*mtx = mtx1;
1106 	mtx_lock(mtx1);
1107 }
1108 
1109 /*
1110  *	vm_page_unhold_pages:
1111  *
1112  *	Unhold each of the pages that is referenced by the given array.
1113  */
1114 void
1115 vm_page_unhold_pages(vm_page_t *ma, int count)
1116 {
1117 
1118 	for (; count != 0; count--) {
1119 		vm_page_unwire(*ma, PQ_ACTIVE);
1120 		ma++;
1121 	}
1122 }
1123 
1124 vm_page_t
1125 PHYS_TO_VM_PAGE(vm_paddr_t pa)
1126 {
1127 	vm_page_t m;
1128 
1129 #ifdef VM_PHYSSEG_SPARSE
1130 	m = vm_phys_paddr_to_vm_page(pa);
1131 	if (m == NULL)
1132 		m = vm_phys_fictitious_to_vm_page(pa);
1133 	return (m);
1134 #elif defined(VM_PHYSSEG_DENSE)
1135 	long pi;
1136 
1137 	pi = atop(pa);
1138 	if (pi >= first_page && (pi - first_page) < vm_page_array_size) {
1139 		m = &vm_page_array[pi - first_page];
1140 		return (m);
1141 	}
1142 	return (vm_phys_fictitious_to_vm_page(pa));
1143 #else
1144 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
1145 #endif
1146 }
1147 
1148 /*
1149  *	vm_page_getfake:
1150  *
1151  *	Create a fictitious page with the specified physical address and
1152  *	memory attribute.  The memory attribute is the only the machine-
1153  *	dependent aspect of a fictitious page that must be initialized.
1154  */
1155 vm_page_t
1156 vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr)
1157 {
1158 	vm_page_t m;
1159 
1160 	m = uma_zalloc(fakepg_zone, M_WAITOK | M_ZERO);
1161 	vm_page_initfake(m, paddr, memattr);
1162 	return (m);
1163 }
1164 
1165 void
1166 vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1167 {
1168 
1169 	if ((m->flags & PG_FICTITIOUS) != 0) {
1170 		/*
1171 		 * The page's memattr might have changed since the
1172 		 * previous initialization.  Update the pmap to the
1173 		 * new memattr.
1174 		 */
1175 		goto memattr;
1176 	}
1177 	m->phys_addr = paddr;
1178 	m->queue = PQ_NONE;
1179 	/* Fictitious pages don't use "segind". */
1180 	m->flags = PG_FICTITIOUS;
1181 	/* Fictitious pages don't use "order" or "pool". */
1182 	m->oflags = VPO_UNMANAGED;
1183 	m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1184 	/* Fictitious pages are unevictable. */
1185 	m->ref_count = 1;
1186 	pmap_page_init(m);
1187 memattr:
1188 	pmap_page_set_memattr(m, memattr);
1189 }
1190 
1191 /*
1192  *	vm_page_putfake:
1193  *
1194  *	Release a fictitious page.
1195  */
1196 void
1197 vm_page_putfake(vm_page_t m)
1198 {
1199 
1200 	KASSERT((m->oflags & VPO_UNMANAGED) != 0, ("managed %p", m));
1201 	KASSERT((m->flags & PG_FICTITIOUS) != 0,
1202 	    ("vm_page_putfake: bad page %p", m));
1203 	uma_zfree(fakepg_zone, m);
1204 }
1205 
1206 /*
1207  *	vm_page_updatefake:
1208  *
1209  *	Update the given fictitious page to the specified physical address and
1210  *	memory attribute.
1211  */
1212 void
1213 vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr)
1214 {
1215 
1216 	KASSERT((m->flags & PG_FICTITIOUS) != 0,
1217 	    ("vm_page_updatefake: bad page %p", m));
1218 	m->phys_addr = paddr;
1219 	pmap_page_set_memattr(m, memattr);
1220 }
1221 
1222 /*
1223  *	vm_page_free:
1224  *
1225  *	Free a page.
1226  */
1227 void
1228 vm_page_free(vm_page_t m)
1229 {
1230 
1231 	m->flags &= ~PG_ZERO;
1232 	vm_page_free_toq(m);
1233 }
1234 
1235 /*
1236  *	vm_page_free_zero:
1237  *
1238  *	Free a page to the zerod-pages queue
1239  */
1240 void
1241 vm_page_free_zero(vm_page_t m)
1242 {
1243 
1244 	m->flags |= PG_ZERO;
1245 	vm_page_free_toq(m);
1246 }
1247 
1248 /*
1249  * Unbusy and handle the page queueing for a page from a getpages request that
1250  * was optionally read ahead or behind.
1251  */
1252 void
1253 vm_page_readahead_finish(vm_page_t m)
1254 {
1255 
1256 	/* We shouldn't put invalid pages on queues. */
1257 	KASSERT(m->valid != 0, ("%s: %p is invalid", __func__, m));
1258 
1259 	/*
1260 	 * Since the page is not the actually needed one, whether it should
1261 	 * be activated or deactivated is not obvious.  Empirical results
1262 	 * have shown that deactivating the page is usually the best choice,
1263 	 * unless the page is wanted by another thread.
1264 	 */
1265 	vm_page_lock(m);
1266 	if ((m->busy_lock & VPB_BIT_WAITERS) != 0)
1267 		vm_page_activate(m);
1268 	else
1269 		vm_page_deactivate(m);
1270 	vm_page_unlock(m);
1271 	vm_page_xunbusy(m);
1272 }
1273 
1274 /*
1275  *	vm_page_sleep_if_busy:
1276  *
1277  *	Sleep and release the object lock if the page is busied.
1278  *	Returns TRUE if the thread slept.
1279  *
1280  *	The given page must be unlocked and object containing it must
1281  *	be locked.
1282  */
1283 int
1284 vm_page_sleep_if_busy(vm_page_t m, const char *msg)
1285 {
1286 	vm_object_t obj;
1287 
1288 	vm_page_lock_assert(m, MA_NOTOWNED);
1289 	VM_OBJECT_ASSERT_WLOCKED(m->object);
1290 
1291 	if (vm_page_busied(m)) {
1292 		/*
1293 		 * The page-specific object must be cached because page
1294 		 * identity can change during the sleep, causing the
1295 		 * re-lock of a different object.
1296 		 * It is assumed that a reference to the object is already
1297 		 * held by the callers.
1298 		 */
1299 		obj = m->object;
1300 		vm_page_busy_sleep(m, msg, false);
1301 		VM_OBJECT_WLOCK(obj);
1302 		return (TRUE);
1303 	}
1304 	return (FALSE);
1305 }
1306 
1307 /*
1308  *	vm_page_sleep_if_xbusy:
1309  *
1310  *	Sleep and release the object lock if the page is xbusied.
1311  *	Returns TRUE if the thread slept.
1312  *
1313  *	The given page must be unlocked and object containing it must
1314  *	be locked.
1315  */
1316 int
1317 vm_page_sleep_if_xbusy(vm_page_t m, const char *msg)
1318 {
1319 	vm_object_t obj;
1320 
1321 	vm_page_lock_assert(m, MA_NOTOWNED);
1322 	VM_OBJECT_ASSERT_WLOCKED(m->object);
1323 
1324 	if (vm_page_xbusied(m)) {
1325 		/*
1326 		 * The page-specific object must be cached because page
1327 		 * identity can change during the sleep, causing the
1328 		 * re-lock of a different object.
1329 		 * It is assumed that a reference to the object is already
1330 		 * held by the callers.
1331 		 */
1332 		obj = m->object;
1333 		vm_page_busy_sleep(m, msg, true);
1334 		VM_OBJECT_WLOCK(obj);
1335 		return (TRUE);
1336 	}
1337 	return (FALSE);
1338 }
1339 
1340 /*
1341  *	vm_page_dirty_KBI:		[ internal use only ]
1342  *
1343  *	Set all bits in the page's dirty field.
1344  *
1345  *	The object containing the specified page must be locked if the
1346  *	call is made from the machine-independent layer.
1347  *
1348  *	See vm_page_clear_dirty_mask().
1349  *
1350  *	This function should only be called by vm_page_dirty().
1351  */
1352 void
1353 vm_page_dirty_KBI(vm_page_t m)
1354 {
1355 
1356 	/* Refer to this operation by its public name. */
1357 	KASSERT(m->valid == VM_PAGE_BITS_ALL,
1358 	    ("vm_page_dirty: page is invalid!"));
1359 	m->dirty = VM_PAGE_BITS_ALL;
1360 }
1361 
1362 /*
1363  *	vm_page_insert:		[ internal use only ]
1364  *
1365  *	Inserts the given mem entry into the object and object list.
1366  *
1367  *	The object must be locked.
1368  */
1369 int
1370 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
1371 {
1372 	vm_page_t mpred;
1373 
1374 	VM_OBJECT_ASSERT_WLOCKED(object);
1375 	mpred = vm_radix_lookup_le(&object->rtree, pindex);
1376 	return (vm_page_insert_after(m, object, pindex, mpred));
1377 }
1378 
1379 /*
1380  *	vm_page_insert_after:
1381  *
1382  *	Inserts the page "m" into the specified object at offset "pindex".
1383  *
1384  *	The page "mpred" must immediately precede the offset "pindex" within
1385  *	the specified object.
1386  *
1387  *	The object must be locked.
1388  */
1389 static int
1390 vm_page_insert_after(vm_page_t m, vm_object_t object, vm_pindex_t pindex,
1391     vm_page_t mpred)
1392 {
1393 	vm_page_t msucc;
1394 
1395 	VM_OBJECT_ASSERT_WLOCKED(object);
1396 	KASSERT(m->object == NULL,
1397 	    ("vm_page_insert_after: page already inserted"));
1398 	if (mpred != NULL) {
1399 		KASSERT(mpred->object == object,
1400 		    ("vm_page_insert_after: object doesn't contain mpred"));
1401 		KASSERT(mpred->pindex < pindex,
1402 		    ("vm_page_insert_after: mpred doesn't precede pindex"));
1403 		msucc = TAILQ_NEXT(mpred, listq);
1404 	} else
1405 		msucc = TAILQ_FIRST(&object->memq);
1406 	if (msucc != NULL)
1407 		KASSERT(msucc->pindex > pindex,
1408 		    ("vm_page_insert_after: msucc doesn't succeed pindex"));
1409 
1410 	/*
1411 	 * Record the object/offset pair in this page.
1412 	 */
1413 	m->object = object;
1414 	m->pindex = pindex;
1415 	m->ref_count |= VPRC_OBJREF;
1416 
1417 	/*
1418 	 * Now link into the object's ordered list of backed pages.
1419 	 */
1420 	if (vm_radix_insert(&object->rtree, m)) {
1421 		m->object = NULL;
1422 		m->pindex = 0;
1423 		m->ref_count &= ~VPRC_OBJREF;
1424 		return (1);
1425 	}
1426 	vm_page_insert_radixdone(m, object, mpred);
1427 	return (0);
1428 }
1429 
1430 /*
1431  *	vm_page_insert_radixdone:
1432  *
1433  *	Complete page "m" insertion into the specified object after the
1434  *	radix trie hooking.
1435  *
1436  *	The page "mpred" must precede the offset "m->pindex" within the
1437  *	specified object.
1438  *
1439  *	The object must be locked.
1440  */
1441 static void
1442 vm_page_insert_radixdone(vm_page_t m, vm_object_t object, vm_page_t mpred)
1443 {
1444 
1445 	VM_OBJECT_ASSERT_WLOCKED(object);
1446 	KASSERT(object != NULL && m->object == object,
1447 	    ("vm_page_insert_radixdone: page %p has inconsistent object", m));
1448 	KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1449 	    ("vm_page_insert_radixdone: page %p is missing object ref", m));
1450 	if (mpred != NULL) {
1451 		KASSERT(mpred->object == object,
1452 		    ("vm_page_insert_radixdone: object doesn't contain mpred"));
1453 		KASSERT(mpred->pindex < m->pindex,
1454 		    ("vm_page_insert_radixdone: mpred doesn't precede pindex"));
1455 	}
1456 
1457 	if (mpred != NULL)
1458 		TAILQ_INSERT_AFTER(&object->memq, mpred, m, listq);
1459 	else
1460 		TAILQ_INSERT_HEAD(&object->memq, m, listq);
1461 
1462 	/*
1463 	 * Show that the object has one more resident page.
1464 	 */
1465 	object->resident_page_count++;
1466 
1467 	/*
1468 	 * Hold the vnode until the last page is released.
1469 	 */
1470 	if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
1471 		vhold(object->handle);
1472 
1473 	/*
1474 	 * Since we are inserting a new and possibly dirty page,
1475 	 * update the object's OBJ_MIGHTBEDIRTY flag.
1476 	 */
1477 	if (pmap_page_is_write_mapped(m))
1478 		vm_object_set_writeable_dirty(object);
1479 }
1480 
1481 /*
1482  * Do the work to remove a page from its object.  The caller is responsible for
1483  * updating the page's fields to reflect this removal.
1484  */
1485 static void
1486 vm_page_object_remove(vm_page_t m)
1487 {
1488 	vm_object_t object;
1489 	vm_page_t mrem;
1490 
1491 	object = m->object;
1492 	VM_OBJECT_ASSERT_WLOCKED(object);
1493 	KASSERT((m->ref_count & VPRC_OBJREF) != 0,
1494 	    ("page %p is missing its object ref", m));
1495 	if (vm_page_xbusied(m))
1496 		vm_page_xunbusy(m);
1497 	mrem = vm_radix_remove(&object->rtree, m->pindex);
1498 	KASSERT(mrem == m, ("removed page %p, expected page %p", mrem, m));
1499 
1500 	/*
1501 	 * Now remove from the object's list of backed pages.
1502 	 */
1503 	TAILQ_REMOVE(&object->memq, m, listq);
1504 
1505 	/*
1506 	 * And show that the object has one fewer resident page.
1507 	 */
1508 	object->resident_page_count--;
1509 
1510 	/*
1511 	 * The vnode may now be recycled.
1512 	 */
1513 	if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
1514 		vdrop(object->handle);
1515 }
1516 
1517 /*
1518  *	vm_page_remove:
1519  *
1520  *	Removes the specified page from its containing object, but does not
1521  *	invalidate any backing storage.  Returns true if the object's reference
1522  *	was the last reference to the page, and false otherwise.
1523  *
1524  *	The object must be locked.
1525  */
1526 bool
1527 vm_page_remove(vm_page_t m)
1528 {
1529 
1530 	vm_page_object_remove(m);
1531 	m->object = NULL;
1532 	return (vm_page_drop(m, VPRC_OBJREF) == VPRC_OBJREF);
1533 }
1534 
1535 /*
1536  *	vm_page_lookup:
1537  *
1538  *	Returns the page associated with the object/offset
1539  *	pair specified; if none is found, NULL is returned.
1540  *
1541  *	The object must be locked.
1542  */
1543 vm_page_t
1544 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
1545 {
1546 
1547 	VM_OBJECT_ASSERT_LOCKED(object);
1548 	return (vm_radix_lookup(&object->rtree, pindex));
1549 }
1550 
1551 /*
1552  *	vm_page_find_least:
1553  *
1554  *	Returns the page associated with the object with least pindex
1555  *	greater than or equal to the parameter pindex, or NULL.
1556  *
1557  *	The object must be locked.
1558  */
1559 vm_page_t
1560 vm_page_find_least(vm_object_t object, vm_pindex_t pindex)
1561 {
1562 	vm_page_t m;
1563 
1564 	VM_OBJECT_ASSERT_LOCKED(object);
1565 	if ((m = TAILQ_FIRST(&object->memq)) != NULL && m->pindex < pindex)
1566 		m = vm_radix_lookup_ge(&object->rtree, pindex);
1567 	return (m);
1568 }
1569 
1570 /*
1571  * Returns the given page's successor (by pindex) within the object if it is
1572  * resident; if none is found, NULL is returned.
1573  *
1574  * The object must be locked.
1575  */
1576 vm_page_t
1577 vm_page_next(vm_page_t m)
1578 {
1579 	vm_page_t next;
1580 
1581 	VM_OBJECT_ASSERT_LOCKED(m->object);
1582 	if ((next = TAILQ_NEXT(m, listq)) != NULL) {
1583 		MPASS(next->object == m->object);
1584 		if (next->pindex != m->pindex + 1)
1585 			next = NULL;
1586 	}
1587 	return (next);
1588 }
1589 
1590 /*
1591  * Returns the given page's predecessor (by pindex) within the object if it is
1592  * resident; if none is found, NULL is returned.
1593  *
1594  * The object must be locked.
1595  */
1596 vm_page_t
1597 vm_page_prev(vm_page_t m)
1598 {
1599 	vm_page_t prev;
1600 
1601 	VM_OBJECT_ASSERT_LOCKED(m->object);
1602 	if ((prev = TAILQ_PREV(m, pglist, listq)) != NULL) {
1603 		MPASS(prev->object == m->object);
1604 		if (prev->pindex != m->pindex - 1)
1605 			prev = NULL;
1606 	}
1607 	return (prev);
1608 }
1609 
1610 /*
1611  * Uses the page mnew as a replacement for an existing page at index
1612  * pindex which must be already present in the object.
1613  */
1614 vm_page_t
1615 vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex)
1616 {
1617 	vm_page_t mold;
1618 
1619 	VM_OBJECT_ASSERT_WLOCKED(object);
1620 	KASSERT(mnew->object == NULL && (mnew->ref_count & VPRC_OBJREF) == 0,
1621 	    ("vm_page_replace: page %p already in object", mnew));
1622 
1623 	/*
1624 	 * This function mostly follows vm_page_insert() and
1625 	 * vm_page_remove() without the radix, object count and vnode
1626 	 * dance.  Double check such functions for more comments.
1627 	 */
1628 
1629 	mnew->object = object;
1630 	mnew->pindex = pindex;
1631 	atomic_set_int(&mnew->ref_count, VPRC_OBJREF);
1632 	mold = vm_radix_replace(&object->rtree, mnew);
1633 	KASSERT(mold->queue == PQ_NONE,
1634 	    ("vm_page_replace: old page %p is on a paging queue", mold));
1635 
1636 	/* Keep the resident page list in sorted order. */
1637 	TAILQ_INSERT_AFTER(&object->memq, mold, mnew, listq);
1638 	TAILQ_REMOVE(&object->memq, mold, listq);
1639 
1640 	mold->object = NULL;
1641 	atomic_clear_int(&mold->ref_count, VPRC_OBJREF);
1642 	vm_page_xunbusy(mold);
1643 
1644 	/*
1645 	 * The object's resident_page_count does not change because we have
1646 	 * swapped one page for another, but OBJ_MIGHTBEDIRTY.
1647 	 */
1648 	if (pmap_page_is_write_mapped(mnew))
1649 		vm_object_set_writeable_dirty(object);
1650 	return (mold);
1651 }
1652 
1653 /*
1654  *	vm_page_rename:
1655  *
1656  *	Move the given memory entry from its
1657  *	current object to the specified target object/offset.
1658  *
1659  *	Note: swap associated with the page must be invalidated by the move.  We
1660  *	      have to do this for several reasons:  (1) we aren't freeing the
1661  *	      page, (2) we are dirtying the page, (3) the VM system is probably
1662  *	      moving the page from object A to B, and will then later move
1663  *	      the backing store from A to B and we can't have a conflict.
1664  *
1665  *	Note: we *always* dirty the page.  It is necessary both for the
1666  *	      fact that we moved it, and because we may be invalidating
1667  *	      swap.
1668  *
1669  *	The objects must be locked.
1670  */
1671 int
1672 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
1673 {
1674 	vm_page_t mpred;
1675 	vm_pindex_t opidx;
1676 
1677 	VM_OBJECT_ASSERT_WLOCKED(new_object);
1678 
1679 	KASSERT(m->ref_count != 0, ("vm_page_rename: page %p has no refs", m));
1680 	mpred = vm_radix_lookup_le(&new_object->rtree, new_pindex);
1681 	KASSERT(mpred == NULL || mpred->pindex != new_pindex,
1682 	    ("vm_page_rename: pindex already renamed"));
1683 
1684 	/*
1685 	 * Create a custom version of vm_page_insert() which does not depend
1686 	 * by m_prev and can cheat on the implementation aspects of the
1687 	 * function.
1688 	 */
1689 	opidx = m->pindex;
1690 	m->pindex = new_pindex;
1691 	if (vm_radix_insert(&new_object->rtree, m)) {
1692 		m->pindex = opidx;
1693 		return (1);
1694 	}
1695 
1696 	/*
1697 	 * The operation cannot fail anymore.  The removal must happen before
1698 	 * the listq iterator is tainted.
1699 	 */
1700 	m->pindex = opidx;
1701 	vm_page_object_remove(m);
1702 
1703 	/* Return back to the new pindex to complete vm_page_insert(). */
1704 	m->pindex = new_pindex;
1705 	m->object = new_object;
1706 
1707 	vm_page_insert_radixdone(m, new_object, mpred);
1708 	vm_page_dirty(m);
1709 	return (0);
1710 }
1711 
1712 /*
1713  *	vm_page_alloc:
1714  *
1715  *	Allocate and return a page that is associated with the specified
1716  *	object and offset pair.  By default, this page is exclusive busied.
1717  *
1718  *	The caller must always specify an allocation class.
1719  *
1720  *	allocation classes:
1721  *	VM_ALLOC_NORMAL		normal process request
1722  *	VM_ALLOC_SYSTEM		system *really* needs a page
1723  *	VM_ALLOC_INTERRUPT	interrupt time request
1724  *
1725  *	optional allocation flags:
1726  *	VM_ALLOC_COUNT(number)	the number of additional pages that the caller
1727  *				intends to allocate
1728  *	VM_ALLOC_NOBUSY		do not exclusive busy the page
1729  *	VM_ALLOC_NODUMP		do not include the page in a kernel core dump
1730  *	VM_ALLOC_NOOBJ		page is not associated with an object and
1731  *				should not be exclusive busy
1732  *	VM_ALLOC_SBUSY		shared busy the allocated page
1733  *	VM_ALLOC_WIRED		wire the allocated page
1734  *	VM_ALLOC_ZERO		prefer a zeroed page
1735  */
1736 vm_page_t
1737 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1738 {
1739 
1740 	return (vm_page_alloc_after(object, pindex, req, object != NULL ?
1741 	    vm_radix_lookup_le(&object->rtree, pindex) : NULL));
1742 }
1743 
1744 vm_page_t
1745 vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
1746     int req)
1747 {
1748 
1749 	return (vm_page_alloc_domain_after(object, pindex, domain, req,
1750 	    object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) :
1751 	    NULL));
1752 }
1753 
1754 /*
1755  * Allocate a page in the specified object with the given page index.  To
1756  * optimize insertion of the page into the object, the caller must also specifiy
1757  * the resident page in the object with largest index smaller than the given
1758  * page index, or NULL if no such page exists.
1759  */
1760 vm_page_t
1761 vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex,
1762     int req, vm_page_t mpred)
1763 {
1764 	struct vm_domainset_iter di;
1765 	vm_page_t m;
1766 	int domain;
1767 
1768 	vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
1769 	do {
1770 		m = vm_page_alloc_domain_after(object, pindex, domain, req,
1771 		    mpred);
1772 		if (m != NULL)
1773 			break;
1774 	} while (vm_domainset_iter_page(&di, object, &domain) == 0);
1775 
1776 	return (m);
1777 }
1778 
1779 /*
1780  * Returns true if the number of free pages exceeds the minimum
1781  * for the request class and false otherwise.
1782  */
1783 int
1784 vm_domain_allocate(struct vm_domain *vmd, int req, int npages)
1785 {
1786 	u_int limit, old, new;
1787 
1788 	req = req & VM_ALLOC_CLASS_MASK;
1789 
1790 	/*
1791 	 * The page daemon is allowed to dig deeper into the free page list.
1792 	 */
1793 	if (curproc == pageproc && req != VM_ALLOC_INTERRUPT)
1794 		req = VM_ALLOC_SYSTEM;
1795 	if (req == VM_ALLOC_INTERRUPT)
1796 		limit = 0;
1797 	else if (req == VM_ALLOC_SYSTEM)
1798 		limit = vmd->vmd_interrupt_free_min;
1799 	else
1800 		limit = vmd->vmd_free_reserved;
1801 
1802 	/*
1803 	 * Attempt to reserve the pages.  Fail if we're below the limit.
1804 	 */
1805 	limit += npages;
1806 	old = vmd->vmd_free_count;
1807 	do {
1808 		if (old < limit)
1809 			return (0);
1810 		new = old - npages;
1811 	} while (atomic_fcmpset_int(&vmd->vmd_free_count, &old, new) == 0);
1812 
1813 	/* Wake the page daemon if we've crossed the threshold. */
1814 	if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old))
1815 		pagedaemon_wakeup(vmd->vmd_domain);
1816 
1817 	/* Only update bitsets on transitions. */
1818 	if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) ||
1819 	    (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe))
1820 		vm_domain_set(vmd);
1821 
1822 	return (1);
1823 }
1824 
1825 vm_page_t
1826 vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
1827     int req, vm_page_t mpred)
1828 {
1829 	struct vm_domain *vmd;
1830 	vm_page_t m;
1831 	int flags, pool;
1832 
1833 	KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
1834 	    (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
1835 	    ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
1836 	    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
1837 	    ("inconsistent object(%p)/req(%x)", object, req));
1838 	KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
1839 	    ("Can't sleep and retry object insertion."));
1840 	KASSERT(mpred == NULL || mpred->pindex < pindex,
1841 	    ("mpred %p doesn't precede pindex 0x%jx", mpred,
1842 	    (uintmax_t)pindex));
1843 	if (object != NULL)
1844 		VM_OBJECT_ASSERT_WLOCKED(object);
1845 
1846 	flags = 0;
1847 	m = NULL;
1848 	pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT;
1849 again:
1850 #if VM_NRESERVLEVEL > 0
1851 	/*
1852 	 * Can we allocate the page from a reservation?
1853 	 */
1854 	if (vm_object_reserv(object) &&
1855 	    (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) !=
1856 	    NULL) {
1857 		domain = vm_phys_domain(m);
1858 		vmd = VM_DOMAIN(domain);
1859 		goto found;
1860 	}
1861 #endif
1862 	vmd = VM_DOMAIN(domain);
1863 	if (vmd->vmd_pgcache[pool].zone != NULL) {
1864 		m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT);
1865 		if (m != NULL) {
1866 			flags |= PG_PCPU_CACHE;
1867 			goto found;
1868 		}
1869 	}
1870 	if (vm_domain_allocate(vmd, req, 1)) {
1871 		/*
1872 		 * If not, allocate it from the free page queues.
1873 		 */
1874 		vm_domain_free_lock(vmd);
1875 		m = vm_phys_alloc_pages(domain, pool, 0);
1876 		vm_domain_free_unlock(vmd);
1877 		if (m == NULL) {
1878 			vm_domain_freecnt_inc(vmd, 1);
1879 #if VM_NRESERVLEVEL > 0
1880 			if (vm_reserv_reclaim_inactive(domain))
1881 				goto again;
1882 #endif
1883 		}
1884 	}
1885 	if (m == NULL) {
1886 		/*
1887 		 * Not allocatable, give up.
1888 		 */
1889 		if (vm_domain_alloc_fail(vmd, object, req))
1890 			goto again;
1891 		return (NULL);
1892 	}
1893 
1894 	/*
1895 	 * At this point we had better have found a good page.
1896 	 */
1897 found:
1898 	vm_page_dequeue(m);
1899 	vm_page_alloc_check(m);
1900 
1901 	/*
1902 	 * Initialize the page.  Only the PG_ZERO flag is inherited.
1903 	 */
1904 	if ((req & VM_ALLOC_ZERO) != 0)
1905 		flags |= (m->flags & PG_ZERO);
1906 	if ((req & VM_ALLOC_NODUMP) != 0)
1907 		flags |= PG_NODUMP;
1908 	m->flags = flags;
1909 	m->aflags = 0;
1910 	m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
1911 	    VPO_UNMANAGED : 0;
1912 	m->busy_lock = VPB_UNBUSIED;
1913 	if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
1914 		m->busy_lock = VPB_SINGLE_EXCLUSIVER;
1915 	if ((req & VM_ALLOC_SBUSY) != 0)
1916 		m->busy_lock = VPB_SHARERS_WORD(1);
1917 	if (req & VM_ALLOC_WIRED) {
1918 		/*
1919 		 * The page lock is not required for wiring a page until that
1920 		 * page is inserted into the object.
1921 		 */
1922 		vm_wire_add(1);
1923 		m->ref_count = 1;
1924 	}
1925 	m->act_count = 0;
1926 
1927 	if (object != NULL) {
1928 		if (vm_page_insert_after(m, object, pindex, mpred)) {
1929 			if (req & VM_ALLOC_WIRED) {
1930 				vm_wire_sub(1);
1931 				m->ref_count = 0;
1932 			}
1933 			KASSERT(m->object == NULL, ("page %p has object", m));
1934 			m->oflags = VPO_UNMANAGED;
1935 			m->busy_lock = VPB_UNBUSIED;
1936 			/* Don't change PG_ZERO. */
1937 			vm_page_free_toq(m);
1938 			if (req & VM_ALLOC_WAITFAIL) {
1939 				VM_OBJECT_WUNLOCK(object);
1940 				vm_radix_wait();
1941 				VM_OBJECT_WLOCK(object);
1942 			}
1943 			return (NULL);
1944 		}
1945 
1946 		/* Ignore device objects; the pager sets "memattr" for them. */
1947 		if (object->memattr != VM_MEMATTR_DEFAULT &&
1948 		    (object->flags & OBJ_FICTITIOUS) == 0)
1949 			pmap_page_set_memattr(m, object->memattr);
1950 	} else
1951 		m->pindex = pindex;
1952 
1953 	return (m);
1954 }
1955 
1956 /*
1957  *	vm_page_alloc_contig:
1958  *
1959  *	Allocate a contiguous set of physical pages of the given size "npages"
1960  *	from the free lists.  All of the physical pages must be at or above
1961  *	the given physical address "low" and below the given physical address
1962  *	"high".  The given value "alignment" determines the alignment of the
1963  *	first physical page in the set.  If the given value "boundary" is
1964  *	non-zero, then the set of physical pages cannot cross any physical
1965  *	address boundary that is a multiple of that value.  Both "alignment"
1966  *	and "boundary" must be a power of two.
1967  *
1968  *	If the specified memory attribute, "memattr", is VM_MEMATTR_DEFAULT,
1969  *	then the memory attribute setting for the physical pages is configured
1970  *	to the object's memory attribute setting.  Otherwise, the memory
1971  *	attribute setting for the physical pages is configured to "memattr",
1972  *	overriding the object's memory attribute setting.  However, if the
1973  *	object's memory attribute setting is not VM_MEMATTR_DEFAULT, then the
1974  *	memory attribute setting for the physical pages cannot be configured
1975  *	to VM_MEMATTR_DEFAULT.
1976  *
1977  *	The specified object may not contain fictitious pages.
1978  *
1979  *	The caller must always specify an allocation class.
1980  *
1981  *	allocation classes:
1982  *	VM_ALLOC_NORMAL		normal process request
1983  *	VM_ALLOC_SYSTEM		system *really* needs a page
1984  *	VM_ALLOC_INTERRUPT	interrupt time request
1985  *
1986  *	optional allocation flags:
1987  *	VM_ALLOC_NOBUSY		do not exclusive busy the page
1988  *	VM_ALLOC_NODUMP		do not include the page in a kernel core dump
1989  *	VM_ALLOC_NOOBJ		page is not associated with an object and
1990  *				should not be exclusive busy
1991  *	VM_ALLOC_SBUSY		shared busy the allocated page
1992  *	VM_ALLOC_WIRED		wire the allocated page
1993  *	VM_ALLOC_ZERO		prefer a zeroed page
1994  */
1995 vm_page_t
1996 vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
1997     u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
1998     vm_paddr_t boundary, vm_memattr_t memattr)
1999 {
2000 	struct vm_domainset_iter di;
2001 	vm_page_t m;
2002 	int domain;
2003 
2004 	vm_domainset_iter_page_init(&di, object, pindex, &domain, &req);
2005 	do {
2006 		m = vm_page_alloc_contig_domain(object, pindex, domain, req,
2007 		    npages, low, high, alignment, boundary, memattr);
2008 		if (m != NULL)
2009 			break;
2010 	} while (vm_domainset_iter_page(&di, object, &domain) == 0);
2011 
2012 	return (m);
2013 }
2014 
2015 vm_page_t
2016 vm_page_alloc_contig_domain(vm_object_t object, vm_pindex_t pindex, int domain,
2017     int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
2018     vm_paddr_t boundary, vm_memattr_t memattr)
2019 {
2020 	struct vm_domain *vmd;
2021 	vm_page_t m, m_ret, mpred;
2022 	u_int busy_lock, flags, oflags;
2023 
2024 	mpred = NULL;	/* XXX: pacify gcc */
2025 	KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
2026 	    (object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
2027 	    ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
2028 	    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
2029 	    ("vm_page_alloc_contig: inconsistent object(%p)/req(%x)", object,
2030 	    req));
2031 	KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
2032 	    ("Can't sleep and retry object insertion."));
2033 	if (object != NULL) {
2034 		VM_OBJECT_ASSERT_WLOCKED(object);
2035 		KASSERT((object->flags & OBJ_FICTITIOUS) == 0,
2036 		    ("vm_page_alloc_contig: object %p has fictitious pages",
2037 		    object));
2038 	}
2039 	KASSERT(npages > 0, ("vm_page_alloc_contig: npages is zero"));
2040 
2041 	if (object != NULL) {
2042 		mpred = vm_radix_lookup_le(&object->rtree, pindex);
2043 		KASSERT(mpred == NULL || mpred->pindex != pindex,
2044 		    ("vm_page_alloc_contig: pindex already allocated"));
2045 	}
2046 
2047 	/*
2048 	 * Can we allocate the pages without the number of free pages falling
2049 	 * below the lower bound for the allocation class?
2050 	 */
2051 	m_ret = NULL;
2052 again:
2053 #if VM_NRESERVLEVEL > 0
2054 	/*
2055 	 * Can we allocate the pages from a reservation?
2056 	 */
2057 	if (vm_object_reserv(object) &&
2058 	    (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req,
2059 	    mpred, npages, low, high, alignment, boundary)) != NULL) {
2060 		domain = vm_phys_domain(m_ret);
2061 		vmd = VM_DOMAIN(domain);
2062 		goto found;
2063 	}
2064 #endif
2065 	vmd = VM_DOMAIN(domain);
2066 	if (vm_domain_allocate(vmd, req, npages)) {
2067 		/*
2068 		 * allocate them from the free page queues.
2069 		 */
2070 		vm_domain_free_lock(vmd);
2071 		m_ret = vm_phys_alloc_contig(domain, npages, low, high,
2072 		    alignment, boundary);
2073 		vm_domain_free_unlock(vmd);
2074 		if (m_ret == NULL) {
2075 			vm_domain_freecnt_inc(vmd, npages);
2076 #if VM_NRESERVLEVEL > 0
2077 			if (vm_reserv_reclaim_contig(domain, npages, low,
2078 			    high, alignment, boundary))
2079 				goto again;
2080 #endif
2081 		}
2082 	}
2083 	if (m_ret == NULL) {
2084 		if (vm_domain_alloc_fail(vmd, object, req))
2085 			goto again;
2086 		return (NULL);
2087 	}
2088 #if VM_NRESERVLEVEL > 0
2089 found:
2090 #endif
2091 	for (m = m_ret; m < &m_ret[npages]; m++) {
2092 		vm_page_dequeue(m);
2093 		vm_page_alloc_check(m);
2094 	}
2095 
2096 	/*
2097 	 * Initialize the pages.  Only the PG_ZERO flag is inherited.
2098 	 */
2099 	flags = 0;
2100 	if ((req & VM_ALLOC_ZERO) != 0)
2101 		flags = PG_ZERO;
2102 	if ((req & VM_ALLOC_NODUMP) != 0)
2103 		flags |= PG_NODUMP;
2104 	oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
2105 	    VPO_UNMANAGED : 0;
2106 	busy_lock = VPB_UNBUSIED;
2107 	if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
2108 		busy_lock = VPB_SINGLE_EXCLUSIVER;
2109 	if ((req & VM_ALLOC_SBUSY) != 0)
2110 		busy_lock = VPB_SHARERS_WORD(1);
2111 	if ((req & VM_ALLOC_WIRED) != 0)
2112 		vm_wire_add(npages);
2113 	if (object != NULL) {
2114 		if (object->memattr != VM_MEMATTR_DEFAULT &&
2115 		    memattr == VM_MEMATTR_DEFAULT)
2116 			memattr = object->memattr;
2117 	}
2118 	for (m = m_ret; m < &m_ret[npages]; m++) {
2119 		m->aflags = 0;
2120 		m->flags = (m->flags | PG_NODUMP) & flags;
2121 		m->busy_lock = busy_lock;
2122 		if ((req & VM_ALLOC_WIRED) != 0)
2123 			m->ref_count = 1;
2124 		m->act_count = 0;
2125 		m->oflags = oflags;
2126 		if (object != NULL) {
2127 			if (vm_page_insert_after(m, object, pindex, mpred)) {
2128 				if ((req & VM_ALLOC_WIRED) != 0)
2129 					vm_wire_sub(npages);
2130 				KASSERT(m->object == NULL,
2131 				    ("page %p has object", m));
2132 				mpred = m;
2133 				for (m = m_ret; m < &m_ret[npages]; m++) {
2134 					if (m <= mpred &&
2135 					    (req & VM_ALLOC_WIRED) != 0)
2136 						m->ref_count = 0;
2137 					m->oflags = VPO_UNMANAGED;
2138 					m->busy_lock = VPB_UNBUSIED;
2139 					/* Don't change PG_ZERO. */
2140 					vm_page_free_toq(m);
2141 				}
2142 				if (req & VM_ALLOC_WAITFAIL) {
2143 					VM_OBJECT_WUNLOCK(object);
2144 					vm_radix_wait();
2145 					VM_OBJECT_WLOCK(object);
2146 				}
2147 				return (NULL);
2148 			}
2149 			mpred = m;
2150 		} else
2151 			m->pindex = pindex;
2152 		if (memattr != VM_MEMATTR_DEFAULT)
2153 			pmap_page_set_memattr(m, memattr);
2154 		pindex++;
2155 	}
2156 	return (m_ret);
2157 }
2158 
2159 /*
2160  * Check a page that has been freshly dequeued from a freelist.
2161  */
2162 static void
2163 vm_page_alloc_check(vm_page_t m)
2164 {
2165 
2166 	KASSERT(m->object == NULL, ("page %p has object", m));
2167 	KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0,
2168 	    ("page %p has unexpected queue %d, flags %#x",
2169 	    m, m->queue, (m->aflags & PGA_QUEUE_STATE_MASK)));
2170 	KASSERT(m->ref_count == 0, ("page %p has references", m));
2171 	KASSERT(!vm_page_busied(m), ("page %p is busy", m));
2172 	KASSERT(m->dirty == 0, ("page %p is dirty", m));
2173 	KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT,
2174 	    ("page %p has unexpected memattr %d",
2175 	    m, pmap_page_get_memattr(m)));
2176 	KASSERT(m->valid == 0, ("free page %p is valid", m));
2177 }
2178 
2179 /*
2180  * 	vm_page_alloc_freelist:
2181  *
2182  *	Allocate a physical page from the specified free page list.
2183  *
2184  *	The caller must always specify an allocation class.
2185  *
2186  *	allocation classes:
2187  *	VM_ALLOC_NORMAL		normal process request
2188  *	VM_ALLOC_SYSTEM		system *really* needs a page
2189  *	VM_ALLOC_INTERRUPT	interrupt time request
2190  *
2191  *	optional allocation flags:
2192  *	VM_ALLOC_COUNT(number)	the number of additional pages that the caller
2193  *				intends to allocate
2194  *	VM_ALLOC_WIRED		wire the allocated page
2195  *	VM_ALLOC_ZERO		prefer a zeroed page
2196  */
2197 vm_page_t
2198 vm_page_alloc_freelist(int freelist, int req)
2199 {
2200 	struct vm_domainset_iter di;
2201 	vm_page_t m;
2202 	int domain;
2203 
2204 	vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2205 	do {
2206 		m = vm_page_alloc_freelist_domain(domain, freelist, req);
2207 		if (m != NULL)
2208 			break;
2209 	} while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2210 
2211 	return (m);
2212 }
2213 
2214 vm_page_t
2215 vm_page_alloc_freelist_domain(int domain, int freelist, int req)
2216 {
2217 	struct vm_domain *vmd;
2218 	vm_page_t m;
2219 	u_int flags;
2220 
2221 	m = NULL;
2222 	vmd = VM_DOMAIN(domain);
2223 again:
2224 	if (vm_domain_allocate(vmd, req, 1)) {
2225 		vm_domain_free_lock(vmd);
2226 		m = vm_phys_alloc_freelist_pages(domain, freelist,
2227 		    VM_FREEPOOL_DIRECT, 0);
2228 		vm_domain_free_unlock(vmd);
2229 		if (m == NULL)
2230 			vm_domain_freecnt_inc(vmd, 1);
2231 	}
2232 	if (m == NULL) {
2233 		if (vm_domain_alloc_fail(vmd, NULL, req))
2234 			goto again;
2235 		return (NULL);
2236 	}
2237 	vm_page_dequeue(m);
2238 	vm_page_alloc_check(m);
2239 
2240 	/*
2241 	 * Initialize the page.  Only the PG_ZERO flag is inherited.
2242 	 */
2243 	m->aflags = 0;
2244 	flags = 0;
2245 	if ((req & VM_ALLOC_ZERO) != 0)
2246 		flags = PG_ZERO;
2247 	m->flags &= flags;
2248 	if ((req & VM_ALLOC_WIRED) != 0) {
2249 		/*
2250 		 * The page lock is not required for wiring a page that does
2251 		 * not belong to an object.
2252 		 */
2253 		vm_wire_add(1);
2254 		m->ref_count = 1;
2255 	}
2256 	/* Unmanaged pages don't use "act_count". */
2257 	m->oflags = VPO_UNMANAGED;
2258 	return (m);
2259 }
2260 
2261 static int
2262 vm_page_zone_import(void *arg, void **store, int cnt, int domain, int flags)
2263 {
2264 	struct vm_domain *vmd;
2265 	struct vm_pgcache *pgcache;
2266 	int i;
2267 
2268 	pgcache = arg;
2269 	vmd = VM_DOMAIN(pgcache->domain);
2270 	/* Only import if we can bring in a full bucket. */
2271 	if (cnt == 1 || !vm_domain_allocate(vmd, VM_ALLOC_NORMAL, cnt))
2272 		return (0);
2273 	domain = vmd->vmd_domain;
2274 	vm_domain_free_lock(vmd);
2275 	i = vm_phys_alloc_npages(domain, pgcache->pool, cnt,
2276 	    (vm_page_t *)store);
2277 	vm_domain_free_unlock(vmd);
2278 	if (cnt != i)
2279 		vm_domain_freecnt_inc(vmd, cnt - i);
2280 
2281 	return (i);
2282 }
2283 
2284 static void
2285 vm_page_zone_release(void *arg, void **store, int cnt)
2286 {
2287 	struct vm_domain *vmd;
2288 	struct vm_pgcache *pgcache;
2289 	vm_page_t m;
2290 	int i;
2291 
2292 	pgcache = arg;
2293 	vmd = VM_DOMAIN(pgcache->domain);
2294 	vm_domain_free_lock(vmd);
2295 	for (i = 0; i < cnt; i++) {
2296 		m = (vm_page_t)store[i];
2297 		vm_phys_free_pages(m, 0);
2298 	}
2299 	vm_domain_free_unlock(vmd);
2300 	vm_domain_freecnt_inc(vmd, cnt);
2301 }
2302 
2303 #define	VPSC_ANY	0	/* No restrictions. */
2304 #define	VPSC_NORESERV	1	/* Skip reservations; implies VPSC_NOSUPER. */
2305 #define	VPSC_NOSUPER	2	/* Skip superpages. */
2306 
2307 /*
2308  *	vm_page_scan_contig:
2309  *
2310  *	Scan vm_page_array[] between the specified entries "m_start" and
2311  *	"m_end" for a run of contiguous physical pages that satisfy the
2312  *	specified conditions, and return the lowest page in the run.  The
2313  *	specified "alignment" determines the alignment of the lowest physical
2314  *	page in the run.  If the specified "boundary" is non-zero, then the
2315  *	run of physical pages cannot span a physical address that is a
2316  *	multiple of "boundary".
2317  *
2318  *	"m_end" is never dereferenced, so it need not point to a vm_page
2319  *	structure within vm_page_array[].
2320  *
2321  *	"npages" must be greater than zero.  "m_start" and "m_end" must not
2322  *	span a hole (or discontiguity) in the physical address space.  Both
2323  *	"alignment" and "boundary" must be a power of two.
2324  */
2325 vm_page_t
2326 vm_page_scan_contig(u_long npages, vm_page_t m_start, vm_page_t m_end,
2327     u_long alignment, vm_paddr_t boundary, int options)
2328 {
2329 	struct mtx *m_mtx;
2330 	vm_object_t object;
2331 	vm_paddr_t pa;
2332 	vm_page_t m, m_run;
2333 #if VM_NRESERVLEVEL > 0
2334 	int level;
2335 #endif
2336 	int m_inc, order, run_ext, run_len;
2337 
2338 	KASSERT(npages > 0, ("npages is 0"));
2339 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2340 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2341 	m_run = NULL;
2342 	run_len = 0;
2343 	m_mtx = NULL;
2344 	for (m = m_start; m < m_end && run_len < npages; m += m_inc) {
2345 		KASSERT((m->flags & PG_MARKER) == 0,
2346 		    ("page %p is PG_MARKER", m));
2347 		KASSERT((m->flags & PG_FICTITIOUS) == 0 || m->ref_count >= 1,
2348 		    ("fictitious page %p has invalid ref count", m));
2349 
2350 		/*
2351 		 * If the current page would be the start of a run, check its
2352 		 * physical address against the end, alignment, and boundary
2353 		 * conditions.  If it doesn't satisfy these conditions, either
2354 		 * terminate the scan or advance to the next page that
2355 		 * satisfies the failed condition.
2356 		 */
2357 		if (run_len == 0) {
2358 			KASSERT(m_run == NULL, ("m_run != NULL"));
2359 			if (m + npages > m_end)
2360 				break;
2361 			pa = VM_PAGE_TO_PHYS(m);
2362 			if ((pa & (alignment - 1)) != 0) {
2363 				m_inc = atop(roundup2(pa, alignment) - pa);
2364 				continue;
2365 			}
2366 			if (rounddown2(pa ^ (pa + ptoa(npages) - 1),
2367 			    boundary) != 0) {
2368 				m_inc = atop(roundup2(pa, boundary) - pa);
2369 				continue;
2370 			}
2371 		} else
2372 			KASSERT(m_run != NULL, ("m_run == NULL"));
2373 
2374 		vm_page_change_lock(m, &m_mtx);
2375 		m_inc = 1;
2376 retry:
2377 		if (vm_page_wired(m))
2378 			run_ext = 0;
2379 #if VM_NRESERVLEVEL > 0
2380 		else if ((level = vm_reserv_level(m)) >= 0 &&
2381 		    (options & VPSC_NORESERV) != 0) {
2382 			run_ext = 0;
2383 			/* Advance to the end of the reservation. */
2384 			pa = VM_PAGE_TO_PHYS(m);
2385 			m_inc = atop(roundup2(pa + 1, vm_reserv_size(level)) -
2386 			    pa);
2387 		}
2388 #endif
2389 		else if ((object = m->object) != NULL) {
2390 			/*
2391 			 * The page is considered eligible for relocation if
2392 			 * and only if it could be laundered or reclaimed by
2393 			 * the page daemon.
2394 			 */
2395 			if (!VM_OBJECT_TRYRLOCK(object)) {
2396 				mtx_unlock(m_mtx);
2397 				VM_OBJECT_RLOCK(object);
2398 				mtx_lock(m_mtx);
2399 				if (m->object != object) {
2400 					/*
2401 					 * The page may have been freed.
2402 					 */
2403 					VM_OBJECT_RUNLOCK(object);
2404 					goto retry;
2405 				}
2406 			}
2407 			/* Don't care: PG_NODUMP, PG_ZERO. */
2408 			if (object->type != OBJT_DEFAULT &&
2409 			    object->type != OBJT_SWAP &&
2410 			    object->type != OBJT_VNODE) {
2411 				run_ext = 0;
2412 #if VM_NRESERVLEVEL > 0
2413 			} else if ((options & VPSC_NOSUPER) != 0 &&
2414 			    (level = vm_reserv_level_iffullpop(m)) >= 0) {
2415 				run_ext = 0;
2416 				/* Advance to the end of the superpage. */
2417 				pa = VM_PAGE_TO_PHYS(m);
2418 				m_inc = atop(roundup2(pa + 1,
2419 				    vm_reserv_size(level)) - pa);
2420 #endif
2421 			} else if (object->memattr == VM_MEMATTR_DEFAULT &&
2422 			    vm_page_queue(m) != PQ_NONE && !vm_page_busied(m) &&
2423 			    !vm_page_wired(m)) {
2424 				/*
2425 				 * The page is allocated but eligible for
2426 				 * relocation.  Extend the current run by one
2427 				 * page.
2428 				 */
2429 				KASSERT(pmap_page_get_memattr(m) ==
2430 				    VM_MEMATTR_DEFAULT,
2431 				    ("page %p has an unexpected memattr", m));
2432 				KASSERT((m->oflags & (VPO_SWAPINPROG |
2433 				    VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2434 				    ("page %p has unexpected oflags", m));
2435 				/* Don't care: VPO_NOSYNC. */
2436 				run_ext = 1;
2437 			} else
2438 				run_ext = 0;
2439 			VM_OBJECT_RUNLOCK(object);
2440 #if VM_NRESERVLEVEL > 0
2441 		} else if (level >= 0) {
2442 			/*
2443 			 * The page is reserved but not yet allocated.  In
2444 			 * other words, it is still free.  Extend the current
2445 			 * run by one page.
2446 			 */
2447 			run_ext = 1;
2448 #endif
2449 		} else if ((order = m->order) < VM_NFREEORDER) {
2450 			/*
2451 			 * The page is enqueued in the physical memory
2452 			 * allocator's free page queues.  Moreover, it is the
2453 			 * first page in a power-of-two-sized run of
2454 			 * contiguous free pages.  Add these pages to the end
2455 			 * of the current run, and jump ahead.
2456 			 */
2457 			run_ext = 1 << order;
2458 			m_inc = 1 << order;
2459 		} else {
2460 			/*
2461 			 * Skip the page for one of the following reasons: (1)
2462 			 * It is enqueued in the physical memory allocator's
2463 			 * free page queues.  However, it is not the first
2464 			 * page in a run of contiguous free pages.  (This case
2465 			 * rarely occurs because the scan is performed in
2466 			 * ascending order.) (2) It is not reserved, and it is
2467 			 * transitioning from free to allocated.  (Conversely,
2468 			 * the transition from allocated to free for managed
2469 			 * pages is blocked by the page lock.) (3) It is
2470 			 * allocated but not contained by an object and not
2471 			 * wired, e.g., allocated by Xen's balloon driver.
2472 			 */
2473 			run_ext = 0;
2474 		}
2475 
2476 		/*
2477 		 * Extend or reset the current run of pages.
2478 		 */
2479 		if (run_ext > 0) {
2480 			if (run_len == 0)
2481 				m_run = m;
2482 			run_len += run_ext;
2483 		} else {
2484 			if (run_len > 0) {
2485 				m_run = NULL;
2486 				run_len = 0;
2487 			}
2488 		}
2489 	}
2490 	if (m_mtx != NULL)
2491 		mtx_unlock(m_mtx);
2492 	if (run_len >= npages)
2493 		return (m_run);
2494 	return (NULL);
2495 }
2496 
2497 /*
2498  *	vm_page_reclaim_run:
2499  *
2500  *	Try to relocate each of the allocated virtual pages within the
2501  *	specified run of physical pages to a new physical address.  Free the
2502  *	physical pages underlying the relocated virtual pages.  A virtual page
2503  *	is relocatable if and only if it could be laundered or reclaimed by
2504  *	the page daemon.  Whenever possible, a virtual page is relocated to a
2505  *	physical address above "high".
2506  *
2507  *	Returns 0 if every physical page within the run was already free or
2508  *	just freed by a successful relocation.  Otherwise, returns a non-zero
2509  *	value indicating why the last attempt to relocate a virtual page was
2510  *	unsuccessful.
2511  *
2512  *	"req_class" must be an allocation class.
2513  */
2514 static int
2515 vm_page_reclaim_run(int req_class, int domain, u_long npages, vm_page_t m_run,
2516     vm_paddr_t high)
2517 {
2518 	struct vm_domain *vmd;
2519 	struct mtx *m_mtx;
2520 	struct spglist free;
2521 	vm_object_t object;
2522 	vm_paddr_t pa;
2523 	vm_page_t m, m_end, m_new;
2524 	int error, order, req;
2525 
2526 	KASSERT((req_class & VM_ALLOC_CLASS_MASK) == req_class,
2527 	    ("req_class is not an allocation class"));
2528 	SLIST_INIT(&free);
2529 	error = 0;
2530 	m = m_run;
2531 	m_end = m_run + npages;
2532 	m_mtx = NULL;
2533 	for (; error == 0 && m < m_end; m++) {
2534 		KASSERT((m->flags & (PG_FICTITIOUS | PG_MARKER)) == 0,
2535 		    ("page %p is PG_FICTITIOUS or PG_MARKER", m));
2536 
2537 		/*
2538 		 * Avoid releasing and reacquiring the same page lock.
2539 		 */
2540 		vm_page_change_lock(m, &m_mtx);
2541 retry:
2542 		/*
2543 		 * Racily check for wirings.  Races are handled below.
2544 		 */
2545 		if (vm_page_wired(m))
2546 			error = EBUSY;
2547 		else if ((object = m->object) != NULL) {
2548 			/*
2549 			 * The page is relocated if and only if it could be
2550 			 * laundered or reclaimed by the page daemon.
2551 			 */
2552 			if (!VM_OBJECT_TRYWLOCK(object)) {
2553 				mtx_unlock(m_mtx);
2554 				VM_OBJECT_WLOCK(object);
2555 				mtx_lock(m_mtx);
2556 				if (m->object != object) {
2557 					/*
2558 					 * The page may have been freed.
2559 					 */
2560 					VM_OBJECT_WUNLOCK(object);
2561 					goto retry;
2562 				}
2563 			}
2564 			/* Don't care: PG_NODUMP, PG_ZERO. */
2565 			if (object->type != OBJT_DEFAULT &&
2566 			    object->type != OBJT_SWAP &&
2567 			    object->type != OBJT_VNODE)
2568 				error = EINVAL;
2569 			else if (object->memattr != VM_MEMATTR_DEFAULT)
2570 				error = EINVAL;
2571 			else if (vm_page_queue(m) != PQ_NONE &&
2572 			    !vm_page_busied(m) && !vm_page_wired(m)) {
2573 				KASSERT(pmap_page_get_memattr(m) ==
2574 				    VM_MEMATTR_DEFAULT,
2575 				    ("page %p has an unexpected memattr", m));
2576 				KASSERT((m->oflags & (VPO_SWAPINPROG |
2577 				    VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0,
2578 				    ("page %p has unexpected oflags", m));
2579 				/* Don't care: VPO_NOSYNC. */
2580 				if (m->valid != 0) {
2581 					/*
2582 					 * First, try to allocate a new page
2583 					 * that is above "high".  Failing
2584 					 * that, try to allocate a new page
2585 					 * that is below "m_run".  Allocate
2586 					 * the new page between the end of
2587 					 * "m_run" and "high" only as a last
2588 					 * resort.
2589 					 */
2590 					req = req_class | VM_ALLOC_NOOBJ;
2591 					if ((m->flags & PG_NODUMP) != 0)
2592 						req |= VM_ALLOC_NODUMP;
2593 					if (trunc_page(high) !=
2594 					    ~(vm_paddr_t)PAGE_MASK) {
2595 						m_new = vm_page_alloc_contig(
2596 						    NULL, 0, req, 1,
2597 						    round_page(high),
2598 						    ~(vm_paddr_t)0,
2599 						    PAGE_SIZE, 0,
2600 						    VM_MEMATTR_DEFAULT);
2601 					} else
2602 						m_new = NULL;
2603 					if (m_new == NULL) {
2604 						pa = VM_PAGE_TO_PHYS(m_run);
2605 						m_new = vm_page_alloc_contig(
2606 						    NULL, 0, req, 1,
2607 						    0, pa - 1, PAGE_SIZE, 0,
2608 						    VM_MEMATTR_DEFAULT);
2609 					}
2610 					if (m_new == NULL) {
2611 						pa += ptoa(npages);
2612 						m_new = vm_page_alloc_contig(
2613 						    NULL, 0, req, 1,
2614 						    pa, high, PAGE_SIZE, 0,
2615 						    VM_MEMATTR_DEFAULT);
2616 					}
2617 					if (m_new == NULL) {
2618 						error = ENOMEM;
2619 						goto unlock;
2620 					}
2621 
2622 					/*
2623 					 * Unmap the page and check for new
2624 					 * wirings that may have been acquired
2625 					 * through a pmap lookup.
2626 					 */
2627 					if (object->ref_count != 0 &&
2628 					    !vm_page_try_remove_all(m)) {
2629 						vm_page_free(m_new);
2630 						error = EBUSY;
2631 						goto unlock;
2632 					}
2633 
2634 					/*
2635 					 * Replace "m" with the new page.  For
2636 					 * vm_page_replace(), "m" must be busy
2637 					 * and dequeued.  Finally, change "m"
2638 					 * as if vm_page_free() was called.
2639 					 */
2640 					m_new->aflags = m->aflags &
2641 					    ~PGA_QUEUE_STATE_MASK;
2642 					KASSERT(m_new->oflags == VPO_UNMANAGED,
2643 					    ("page %p is managed", m_new));
2644 					m_new->oflags = m->oflags & VPO_NOSYNC;
2645 					pmap_copy_page(m, m_new);
2646 					m_new->valid = m->valid;
2647 					m_new->dirty = m->dirty;
2648 					m->flags &= ~PG_ZERO;
2649 					vm_page_xbusy(m);
2650 					vm_page_dequeue(m);
2651 					vm_page_replace_checked(m_new, object,
2652 					    m->pindex, m);
2653 					if (vm_page_free_prep(m))
2654 						SLIST_INSERT_HEAD(&free, m,
2655 						    plinks.s.ss);
2656 
2657 					/*
2658 					 * The new page must be deactivated
2659 					 * before the object is unlocked.
2660 					 */
2661 					vm_page_change_lock(m_new, &m_mtx);
2662 					vm_page_deactivate(m_new);
2663 				} else {
2664 					m->flags &= ~PG_ZERO;
2665 					vm_page_dequeue(m);
2666 					if (vm_page_free_prep(m))
2667 						SLIST_INSERT_HEAD(&free, m,
2668 						    plinks.s.ss);
2669 					KASSERT(m->dirty == 0,
2670 					    ("page %p is dirty", m));
2671 				}
2672 			} else
2673 				error = EBUSY;
2674 unlock:
2675 			VM_OBJECT_WUNLOCK(object);
2676 		} else {
2677 			MPASS(vm_phys_domain(m) == domain);
2678 			vmd = VM_DOMAIN(domain);
2679 			vm_domain_free_lock(vmd);
2680 			order = m->order;
2681 			if (order < VM_NFREEORDER) {
2682 				/*
2683 				 * The page is enqueued in the physical memory
2684 				 * allocator's free page queues.  Moreover, it
2685 				 * is the first page in a power-of-two-sized
2686 				 * run of contiguous free pages.  Jump ahead
2687 				 * to the last page within that run, and
2688 				 * continue from there.
2689 				 */
2690 				m += (1 << order) - 1;
2691 			}
2692 #if VM_NRESERVLEVEL > 0
2693 			else if (vm_reserv_is_page_free(m))
2694 				order = 0;
2695 #endif
2696 			vm_domain_free_unlock(vmd);
2697 			if (order == VM_NFREEORDER)
2698 				error = EINVAL;
2699 		}
2700 	}
2701 	if (m_mtx != NULL)
2702 		mtx_unlock(m_mtx);
2703 	if ((m = SLIST_FIRST(&free)) != NULL) {
2704 		int cnt;
2705 
2706 		vmd = VM_DOMAIN(domain);
2707 		cnt = 0;
2708 		vm_domain_free_lock(vmd);
2709 		do {
2710 			MPASS(vm_phys_domain(m) == domain);
2711 			SLIST_REMOVE_HEAD(&free, plinks.s.ss);
2712 			vm_phys_free_pages(m, 0);
2713 			cnt++;
2714 		} while ((m = SLIST_FIRST(&free)) != NULL);
2715 		vm_domain_free_unlock(vmd);
2716 		vm_domain_freecnt_inc(vmd, cnt);
2717 	}
2718 	return (error);
2719 }
2720 
2721 #define	NRUNS	16
2722 
2723 CTASSERT(powerof2(NRUNS));
2724 
2725 #define	RUN_INDEX(count)	((count) & (NRUNS - 1))
2726 
2727 #define	MIN_RECLAIM	8
2728 
2729 /*
2730  *	vm_page_reclaim_contig:
2731  *
2732  *	Reclaim allocated, contiguous physical memory satisfying the specified
2733  *	conditions by relocating the virtual pages using that physical memory.
2734  *	Returns true if reclamation is successful and false otherwise.  Since
2735  *	relocation requires the allocation of physical pages, reclamation may
2736  *	fail due to a shortage of free pages.  When reclamation fails, callers
2737  *	are expected to perform vm_wait() before retrying a failed allocation
2738  *	operation, e.g., vm_page_alloc_contig().
2739  *
2740  *	The caller must always specify an allocation class through "req".
2741  *
2742  *	allocation classes:
2743  *	VM_ALLOC_NORMAL		normal process request
2744  *	VM_ALLOC_SYSTEM		system *really* needs a page
2745  *	VM_ALLOC_INTERRUPT	interrupt time request
2746  *
2747  *	The optional allocation flags are ignored.
2748  *
2749  *	"npages" must be greater than zero.  Both "alignment" and "boundary"
2750  *	must be a power of two.
2751  */
2752 bool
2753 vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
2754     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
2755 {
2756 	struct vm_domain *vmd;
2757 	vm_paddr_t curr_low;
2758 	vm_page_t m_run, m_runs[NRUNS];
2759 	u_long count, reclaimed;
2760 	int error, i, options, req_class;
2761 
2762 	KASSERT(npages > 0, ("npages is 0"));
2763 	KASSERT(powerof2(alignment), ("alignment is not a power of 2"));
2764 	KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
2765 	req_class = req & VM_ALLOC_CLASS_MASK;
2766 
2767 	/*
2768 	 * The page daemon is allowed to dig deeper into the free page list.
2769 	 */
2770 	if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT)
2771 		req_class = VM_ALLOC_SYSTEM;
2772 
2773 	/*
2774 	 * Return if the number of free pages cannot satisfy the requested
2775 	 * allocation.
2776 	 */
2777 	vmd = VM_DOMAIN(domain);
2778 	count = vmd->vmd_free_count;
2779 	if (count < npages + vmd->vmd_free_reserved || (count < npages +
2780 	    vmd->vmd_interrupt_free_min && req_class == VM_ALLOC_SYSTEM) ||
2781 	    (count < npages && req_class == VM_ALLOC_INTERRUPT))
2782 		return (false);
2783 
2784 	/*
2785 	 * Scan up to three times, relaxing the restrictions ("options") on
2786 	 * the reclamation of reservations and superpages each time.
2787 	 */
2788 	for (options = VPSC_NORESERV;;) {
2789 		/*
2790 		 * Find the highest runs that satisfy the given constraints
2791 		 * and restrictions, and record them in "m_runs".
2792 		 */
2793 		curr_low = low;
2794 		count = 0;
2795 		for (;;) {
2796 			m_run = vm_phys_scan_contig(domain, npages, curr_low,
2797 			    high, alignment, boundary, options);
2798 			if (m_run == NULL)
2799 				break;
2800 			curr_low = VM_PAGE_TO_PHYS(m_run) + ptoa(npages);
2801 			m_runs[RUN_INDEX(count)] = m_run;
2802 			count++;
2803 		}
2804 
2805 		/*
2806 		 * Reclaim the highest runs in LIFO (descending) order until
2807 		 * the number of reclaimed pages, "reclaimed", is at least
2808 		 * MIN_RECLAIM.  Reset "reclaimed" each time because each
2809 		 * reclamation is idempotent, and runs will (likely) recur
2810 		 * from one scan to the next as restrictions are relaxed.
2811 		 */
2812 		reclaimed = 0;
2813 		for (i = 0; count > 0 && i < NRUNS; i++) {
2814 			count--;
2815 			m_run = m_runs[RUN_INDEX(count)];
2816 			error = vm_page_reclaim_run(req_class, domain, npages,
2817 			    m_run, high);
2818 			if (error == 0) {
2819 				reclaimed += npages;
2820 				if (reclaimed >= MIN_RECLAIM)
2821 					return (true);
2822 			}
2823 		}
2824 
2825 		/*
2826 		 * Either relax the restrictions on the next scan or return if
2827 		 * the last scan had no restrictions.
2828 		 */
2829 		if (options == VPSC_NORESERV)
2830 			options = VPSC_NOSUPER;
2831 		else if (options == VPSC_NOSUPER)
2832 			options = VPSC_ANY;
2833 		else if (options == VPSC_ANY)
2834 			return (reclaimed != 0);
2835 	}
2836 }
2837 
2838 bool
2839 vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low, vm_paddr_t high,
2840     u_long alignment, vm_paddr_t boundary)
2841 {
2842 	struct vm_domainset_iter di;
2843 	int domain;
2844 	bool ret;
2845 
2846 	vm_domainset_iter_page_init(&di, NULL, 0, &domain, &req);
2847 	do {
2848 		ret = vm_page_reclaim_contig_domain(domain, req, npages, low,
2849 		    high, alignment, boundary);
2850 		if (ret)
2851 			break;
2852 	} while (vm_domainset_iter_page(&di, NULL, &domain) == 0);
2853 
2854 	return (ret);
2855 }
2856 
2857 /*
2858  * Set the domain in the appropriate page level domainset.
2859  */
2860 void
2861 vm_domain_set(struct vm_domain *vmd)
2862 {
2863 
2864 	mtx_lock(&vm_domainset_lock);
2865 	if (!vmd->vmd_minset && vm_paging_min(vmd)) {
2866 		vmd->vmd_minset = 1;
2867 		DOMAINSET_SET(vmd->vmd_domain, &vm_min_domains);
2868 	}
2869 	if (!vmd->vmd_severeset && vm_paging_severe(vmd)) {
2870 		vmd->vmd_severeset = 1;
2871 		DOMAINSET_SET(vmd->vmd_domain, &vm_severe_domains);
2872 	}
2873 	mtx_unlock(&vm_domainset_lock);
2874 }
2875 
2876 /*
2877  * Clear the domain from the appropriate page level domainset.
2878  */
2879 void
2880 vm_domain_clear(struct vm_domain *vmd)
2881 {
2882 
2883 	mtx_lock(&vm_domainset_lock);
2884 	if (vmd->vmd_minset && !vm_paging_min(vmd)) {
2885 		vmd->vmd_minset = 0;
2886 		DOMAINSET_CLR(vmd->vmd_domain, &vm_min_domains);
2887 		if (vm_min_waiters != 0) {
2888 			vm_min_waiters = 0;
2889 			wakeup(&vm_min_domains);
2890 		}
2891 	}
2892 	if (vmd->vmd_severeset && !vm_paging_severe(vmd)) {
2893 		vmd->vmd_severeset = 0;
2894 		DOMAINSET_CLR(vmd->vmd_domain, &vm_severe_domains);
2895 		if (vm_severe_waiters != 0) {
2896 			vm_severe_waiters = 0;
2897 			wakeup(&vm_severe_domains);
2898 		}
2899 	}
2900 
2901 	/*
2902 	 * If pageout daemon needs pages, then tell it that there are
2903 	 * some free.
2904 	 */
2905 	if (vmd->vmd_pageout_pages_needed &&
2906 	    vmd->vmd_free_count >= vmd->vmd_pageout_free_min) {
2907 		wakeup(&vmd->vmd_pageout_pages_needed);
2908 		vmd->vmd_pageout_pages_needed = 0;
2909 	}
2910 
2911 	/* See comments in vm_wait_doms(). */
2912 	if (vm_pageproc_waiters) {
2913 		vm_pageproc_waiters = 0;
2914 		wakeup(&vm_pageproc_waiters);
2915 	}
2916 	mtx_unlock(&vm_domainset_lock);
2917 }
2918 
2919 /*
2920  * Wait for free pages to exceed the min threshold globally.
2921  */
2922 void
2923 vm_wait_min(void)
2924 {
2925 
2926 	mtx_lock(&vm_domainset_lock);
2927 	while (vm_page_count_min()) {
2928 		vm_min_waiters++;
2929 		msleep(&vm_min_domains, &vm_domainset_lock, PVM, "vmwait", 0);
2930 	}
2931 	mtx_unlock(&vm_domainset_lock);
2932 }
2933 
2934 /*
2935  * Wait for free pages to exceed the severe threshold globally.
2936  */
2937 void
2938 vm_wait_severe(void)
2939 {
2940 
2941 	mtx_lock(&vm_domainset_lock);
2942 	while (vm_page_count_severe()) {
2943 		vm_severe_waiters++;
2944 		msleep(&vm_severe_domains, &vm_domainset_lock, PVM,
2945 		    "vmwait", 0);
2946 	}
2947 	mtx_unlock(&vm_domainset_lock);
2948 }
2949 
2950 u_int
2951 vm_wait_count(void)
2952 {
2953 
2954 	return (vm_severe_waiters + vm_min_waiters + vm_pageproc_waiters);
2955 }
2956 
2957 void
2958 vm_wait_doms(const domainset_t *wdoms)
2959 {
2960 
2961 	/*
2962 	 * We use racey wakeup synchronization to avoid expensive global
2963 	 * locking for the pageproc when sleeping with a non-specific vm_wait.
2964 	 * To handle this, we only sleep for one tick in this instance.  It
2965 	 * is expected that most allocations for the pageproc will come from
2966 	 * kmem or vm_page_grab* which will use the more specific and
2967 	 * race-free vm_wait_domain().
2968 	 */
2969 	if (curproc == pageproc) {
2970 		mtx_lock(&vm_domainset_lock);
2971 		vm_pageproc_waiters++;
2972 		msleep(&vm_pageproc_waiters, &vm_domainset_lock, PVM | PDROP,
2973 		    "pageprocwait", 1);
2974 	} else {
2975 		/*
2976 		 * XXX Ideally we would wait only until the allocation could
2977 		 * be satisfied.  This condition can cause new allocators to
2978 		 * consume all freed pages while old allocators wait.
2979 		 */
2980 		mtx_lock(&vm_domainset_lock);
2981 		if (vm_page_count_min_set(wdoms)) {
2982 			vm_min_waiters++;
2983 			msleep(&vm_min_domains, &vm_domainset_lock,
2984 			    PVM | PDROP, "vmwait", 0);
2985 		} else
2986 			mtx_unlock(&vm_domainset_lock);
2987 	}
2988 }
2989 
2990 /*
2991  *	vm_wait_domain:
2992  *
2993  *	Sleep until free pages are available for allocation.
2994  *	- Called in various places after failed memory allocations.
2995  */
2996 void
2997 vm_wait_domain(int domain)
2998 {
2999 	struct vm_domain *vmd;
3000 	domainset_t wdom;
3001 
3002 	vmd = VM_DOMAIN(domain);
3003 	vm_domain_free_assert_unlocked(vmd);
3004 
3005 	if (curproc == pageproc) {
3006 		mtx_lock(&vm_domainset_lock);
3007 		if (vmd->vmd_free_count < vmd->vmd_pageout_free_min) {
3008 			vmd->vmd_pageout_pages_needed = 1;
3009 			msleep(&vmd->vmd_pageout_pages_needed,
3010 			    &vm_domainset_lock, PDROP | PSWP, "VMWait", 0);
3011 		} else
3012 			mtx_unlock(&vm_domainset_lock);
3013 	} else {
3014 		if (pageproc == NULL)
3015 			panic("vm_wait in early boot");
3016 		DOMAINSET_ZERO(&wdom);
3017 		DOMAINSET_SET(vmd->vmd_domain, &wdom);
3018 		vm_wait_doms(&wdom);
3019 	}
3020 }
3021 
3022 /*
3023  *	vm_wait:
3024  *
3025  *	Sleep until free pages are available for allocation in the
3026  *	affinity domains of the obj.  If obj is NULL, the domain set
3027  *	for the calling thread is used.
3028  *	Called in various places after failed memory allocations.
3029  */
3030 void
3031 vm_wait(vm_object_t obj)
3032 {
3033 	struct domainset *d;
3034 
3035 	d = NULL;
3036 
3037 	/*
3038 	 * Carefully fetch pointers only once: the struct domainset
3039 	 * itself is ummutable but the pointer might change.
3040 	 */
3041 	if (obj != NULL)
3042 		d = obj->domain.dr_policy;
3043 	if (d == NULL)
3044 		d = curthread->td_domain.dr_policy;
3045 
3046 	vm_wait_doms(&d->ds_mask);
3047 }
3048 
3049 /*
3050  *	vm_domain_alloc_fail:
3051  *
3052  *	Called when a page allocation function fails.  Informs the
3053  *	pagedaemon and performs the requested wait.  Requires the
3054  *	domain_free and object lock on entry.  Returns with the
3055  *	object lock held and free lock released.  Returns an error when
3056  *	retry is necessary.
3057  *
3058  */
3059 static int
3060 vm_domain_alloc_fail(struct vm_domain *vmd, vm_object_t object, int req)
3061 {
3062 
3063 	vm_domain_free_assert_unlocked(vmd);
3064 
3065 	atomic_add_int(&vmd->vmd_pageout_deficit,
3066 	    max((u_int)req >> VM_ALLOC_COUNT_SHIFT, 1));
3067 	if (req & (VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL)) {
3068 		if (object != NULL)
3069 			VM_OBJECT_WUNLOCK(object);
3070 		vm_wait_domain(vmd->vmd_domain);
3071 		if (object != NULL)
3072 			VM_OBJECT_WLOCK(object);
3073 		if (req & VM_ALLOC_WAITOK)
3074 			return (EAGAIN);
3075 	}
3076 
3077 	return (0);
3078 }
3079 
3080 /*
3081  *	vm_waitpfault:
3082  *
3083  *	Sleep until free pages are available for allocation.
3084  *	- Called only in vm_fault so that processes page faulting
3085  *	  can be easily tracked.
3086  *	- Sleeps at a lower priority than vm_wait() so that vm_wait()ing
3087  *	  processes will be able to grab memory first.  Do not change
3088  *	  this balance without careful testing first.
3089  */
3090 void
3091 vm_waitpfault(struct domainset *dset, int timo)
3092 {
3093 
3094 	/*
3095 	 * XXX Ideally we would wait only until the allocation could
3096 	 * be satisfied.  This condition can cause new allocators to
3097 	 * consume all freed pages while old allocators wait.
3098 	 */
3099 	mtx_lock(&vm_domainset_lock);
3100 	if (vm_page_count_min_set(&dset->ds_mask)) {
3101 		vm_min_waiters++;
3102 		msleep(&vm_min_domains, &vm_domainset_lock, PUSER | PDROP,
3103 		    "pfault", timo);
3104 	} else
3105 		mtx_unlock(&vm_domainset_lock);
3106 }
3107 
3108 static struct vm_pagequeue *
3109 vm_page_pagequeue(vm_page_t m)
3110 {
3111 
3112 	uint8_t queue;
3113 
3114 	if ((queue = atomic_load_8(&m->queue)) == PQ_NONE)
3115 		return (NULL);
3116 	return (&vm_pagequeue_domain(m)->vmd_pagequeues[queue]);
3117 }
3118 
3119 static inline void
3120 vm_pqbatch_process_page(struct vm_pagequeue *pq, vm_page_t m)
3121 {
3122 	struct vm_domain *vmd;
3123 	uint8_t qflags;
3124 
3125 	CRITICAL_ASSERT(curthread);
3126 	vm_pagequeue_assert_locked(pq);
3127 
3128 	/*
3129 	 * The page daemon is allowed to set m->queue = PQ_NONE without
3130 	 * the page queue lock held.  In this case it is about to free the page,
3131 	 * which must not have any queue state.
3132 	 */
3133 	qflags = atomic_load_8(&m->aflags);
3134 	KASSERT(pq == vm_page_pagequeue(m) ||
3135 	    (qflags & PGA_QUEUE_STATE_MASK) == 0,
3136 	    ("page %p doesn't belong to queue %p but has aflags %#x",
3137 	    m, pq, qflags));
3138 
3139 	if ((qflags & PGA_DEQUEUE) != 0) {
3140 		if (__predict_true((qflags & PGA_ENQUEUED) != 0))
3141 			vm_pagequeue_remove(pq, m);
3142 		vm_page_dequeue_complete(m);
3143 		counter_u64_add(queue_ops, 1);
3144 	} else if ((qflags & (PGA_REQUEUE | PGA_REQUEUE_HEAD)) != 0) {
3145 		if ((qflags & PGA_ENQUEUED) != 0)
3146 			TAILQ_REMOVE(&pq->pq_pl, m, plinks.q);
3147 		else {
3148 			vm_pagequeue_cnt_inc(pq);
3149 			vm_page_aflag_set(m, PGA_ENQUEUED);
3150 		}
3151 
3152 		/*
3153 		 * Give PGA_REQUEUE_HEAD precedence over PGA_REQUEUE.
3154 		 * In particular, if both flags are set in close succession,
3155 		 * only PGA_REQUEUE_HEAD will be applied, even if it was set
3156 		 * first.
3157 		 */
3158 		if ((qflags & PGA_REQUEUE_HEAD) != 0) {
3159 			KASSERT(m->queue == PQ_INACTIVE,
3160 			    ("head enqueue not supported for page %p", m));
3161 			vmd = vm_pagequeue_domain(m);
3162 			TAILQ_INSERT_BEFORE(&vmd->vmd_inacthead, m, plinks.q);
3163 		} else
3164 			TAILQ_INSERT_TAIL(&pq->pq_pl, m, plinks.q);
3165 
3166 		vm_page_aflag_clear(m, qflags & (PGA_REQUEUE |
3167 		    PGA_REQUEUE_HEAD));
3168 		counter_u64_add(queue_ops, 1);
3169 	} else {
3170 		counter_u64_add(queue_nops, 1);
3171 	}
3172 }
3173 
3174 static void
3175 vm_pqbatch_process(struct vm_pagequeue *pq, struct vm_batchqueue *bq,
3176     uint8_t queue)
3177 {
3178 	vm_page_t m;
3179 	int i;
3180 
3181 	for (i = 0; i < bq->bq_cnt; i++) {
3182 		m = bq->bq_pa[i];
3183 		if (__predict_false(m->queue != queue))
3184 			continue;
3185 		vm_pqbatch_process_page(pq, m);
3186 	}
3187 	vm_batchqueue_init(bq);
3188 }
3189 
3190 /*
3191  *	vm_page_pqbatch_submit:		[ internal use only ]
3192  *
3193  *	Enqueue a page in the specified page queue's batched work queue.
3194  *	The caller must have encoded the requested operation in the page
3195  *	structure's aflags field.
3196  */
3197 void
3198 vm_page_pqbatch_submit(vm_page_t m, uint8_t queue)
3199 {
3200 	struct vm_batchqueue *bq;
3201 	struct vm_pagequeue *pq;
3202 	int domain;
3203 
3204 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3205 	    ("page %p is unmanaged", m));
3206 	KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL,
3207 	    ("missing synchronization for page %p", m));
3208 	KASSERT(queue < PQ_COUNT, ("invalid queue %d", queue));
3209 
3210 	domain = vm_phys_domain(m);
3211 	pq = &vm_pagequeue_domain(m)->vmd_pagequeues[queue];
3212 
3213 	critical_enter();
3214 	bq = DPCPU_PTR(pqbatch[domain][queue]);
3215 	if (vm_batchqueue_insert(bq, m)) {
3216 		critical_exit();
3217 		return;
3218 	}
3219 	if (!vm_pagequeue_trylock(pq)) {
3220 		critical_exit();
3221 		vm_pagequeue_lock(pq);
3222 		critical_enter();
3223 		bq = DPCPU_PTR(pqbatch[domain][queue]);
3224 	}
3225 	vm_pqbatch_process(pq, bq, queue);
3226 
3227 	/*
3228 	 * The page may have been logically dequeued before we acquired the
3229 	 * page queue lock.  In this case, since we either hold the page lock
3230 	 * or the page is being freed, a different thread cannot be concurrently
3231 	 * enqueuing the page.
3232 	 */
3233 	if (__predict_true(m->queue == queue))
3234 		vm_pqbatch_process_page(pq, m);
3235 	else {
3236 		KASSERT(m->queue == PQ_NONE,
3237 		    ("invalid queue transition for page %p", m));
3238 		KASSERT((m->aflags & PGA_ENQUEUED) == 0,
3239 		    ("page %p is enqueued with invalid queue index", m));
3240 	}
3241 	vm_pagequeue_unlock(pq);
3242 	critical_exit();
3243 }
3244 
3245 /*
3246  *	vm_page_pqbatch_drain:		[ internal use only ]
3247  *
3248  *	Force all per-CPU page queue batch queues to be drained.  This is
3249  *	intended for use in severe memory shortages, to ensure that pages
3250  *	do not remain stuck in the batch queues.
3251  */
3252 void
3253 vm_page_pqbatch_drain(void)
3254 {
3255 	struct thread *td;
3256 	struct vm_domain *vmd;
3257 	struct vm_pagequeue *pq;
3258 	int cpu, domain, queue;
3259 
3260 	td = curthread;
3261 	CPU_FOREACH(cpu) {
3262 		thread_lock(td);
3263 		sched_bind(td, cpu);
3264 		thread_unlock(td);
3265 
3266 		for (domain = 0; domain < vm_ndomains; domain++) {
3267 			vmd = VM_DOMAIN(domain);
3268 			for (queue = 0; queue < PQ_COUNT; queue++) {
3269 				pq = &vmd->vmd_pagequeues[queue];
3270 				vm_pagequeue_lock(pq);
3271 				critical_enter();
3272 				vm_pqbatch_process(pq,
3273 				    DPCPU_PTR(pqbatch[domain][queue]), queue);
3274 				critical_exit();
3275 				vm_pagequeue_unlock(pq);
3276 			}
3277 		}
3278 	}
3279 	thread_lock(td);
3280 	sched_unbind(td);
3281 	thread_unlock(td);
3282 }
3283 
3284 /*
3285  * Complete the logical removal of a page from a page queue.  We must be
3286  * careful to synchronize with the page daemon, which may be concurrently
3287  * examining the page with only the page lock held.  The page must not be
3288  * in a state where it appears to be logically enqueued.
3289  */
3290 static void
3291 vm_page_dequeue_complete(vm_page_t m)
3292 {
3293 
3294 	m->queue = PQ_NONE;
3295 	atomic_thread_fence_rel();
3296 	vm_page_aflag_clear(m, PGA_QUEUE_STATE_MASK);
3297 }
3298 
3299 /*
3300  *	vm_page_dequeue_deferred:	[ internal use only ]
3301  *
3302  *	Request removal of the given page from its current page
3303  *	queue.  Physical removal from the queue may be deferred
3304  *	indefinitely.
3305  *
3306  *	The page must be locked.
3307  */
3308 void
3309 vm_page_dequeue_deferred(vm_page_t m)
3310 {
3311 	uint8_t queue;
3312 
3313 	vm_page_assert_locked(m);
3314 
3315 	if ((queue = vm_page_queue(m)) == PQ_NONE)
3316 		return;
3317 
3318 	/*
3319 	 * Set PGA_DEQUEUE if it is not already set to handle a concurrent call
3320 	 * to vm_page_dequeue_deferred_free().  In particular, avoid modifying
3321 	 * the page's queue state once vm_page_dequeue_deferred_free() has been
3322 	 * called.  In the event of a race, two batch queue entries for the page
3323 	 * will be created, but the second will have no effect.
3324 	 */
3325 	if (vm_page_pqstate_cmpset(m, queue, queue, PGA_DEQUEUE, PGA_DEQUEUE))
3326 		vm_page_pqbatch_submit(m, queue);
3327 }
3328 
3329 /*
3330  * A variant of vm_page_dequeue_deferred() that does not assert the page
3331  * lock and is only to be called from vm_page_free_prep().  Because the
3332  * page is being freed, we can assume that nothing other than the page
3333  * daemon is scheduling queue operations on this page, so we get for
3334  * free the mutual exclusion that is otherwise provided by the page lock.
3335  * To handle races, the page daemon must take care to atomically check
3336  * for PGA_DEQUEUE when updating queue state.
3337  */
3338 static void
3339 vm_page_dequeue_deferred_free(vm_page_t m)
3340 {
3341 	uint8_t queue;
3342 
3343 	KASSERT(m->ref_count == 0, ("page %p has references", m));
3344 
3345 	for (;;) {
3346 		if ((m->aflags & PGA_DEQUEUE) != 0)
3347 			return;
3348 		atomic_thread_fence_acq();
3349 		if ((queue = atomic_load_8(&m->queue)) == PQ_NONE)
3350 			return;
3351 		if (vm_page_pqstate_cmpset(m, queue, queue, PGA_DEQUEUE,
3352 		    PGA_DEQUEUE)) {
3353 			vm_page_pqbatch_submit(m, queue);
3354 			break;
3355 		}
3356 	}
3357 }
3358 
3359 /*
3360  *	vm_page_dequeue:
3361  *
3362  *	Remove the page from whichever page queue it's in, if any.
3363  *	The page must either be locked or unallocated.  This constraint
3364  *	ensures that the queue state of the page will remain consistent
3365  *	after this function returns.
3366  */
3367 void
3368 vm_page_dequeue(vm_page_t m)
3369 {
3370 	struct vm_pagequeue *pq, *pq1;
3371 	uint8_t aflags;
3372 
3373 	KASSERT(mtx_owned(vm_page_lockptr(m)) || m->object == NULL,
3374 	    ("page %p is allocated and unlocked", m));
3375 
3376 	for (pq = vm_page_pagequeue(m);; pq = pq1) {
3377 		if (pq == NULL) {
3378 			/*
3379 			 * A thread may be concurrently executing
3380 			 * vm_page_dequeue_complete().  Ensure that all queue
3381 			 * state is cleared before we return.
3382 			 */
3383 			aflags = atomic_load_8(&m->aflags);
3384 			if ((aflags & PGA_QUEUE_STATE_MASK) == 0)
3385 				return;
3386 			KASSERT((aflags & PGA_DEQUEUE) != 0,
3387 			    ("page %p has unexpected queue state flags %#x",
3388 			    m, aflags));
3389 
3390 			/*
3391 			 * Busy wait until the thread updating queue state is
3392 			 * finished.  Such a thread must be executing in a
3393 			 * critical section.
3394 			 */
3395 			cpu_spinwait();
3396 			pq1 = vm_page_pagequeue(m);
3397 			continue;
3398 		}
3399 		vm_pagequeue_lock(pq);
3400 		if ((pq1 = vm_page_pagequeue(m)) == pq)
3401 			break;
3402 		vm_pagequeue_unlock(pq);
3403 	}
3404 	KASSERT(pq == vm_page_pagequeue(m),
3405 	    ("%s: page %p migrated directly between queues", __func__, m));
3406 	KASSERT((m->aflags & PGA_DEQUEUE) != 0 ||
3407 	    mtx_owned(vm_page_lockptr(m)),
3408 	    ("%s: queued unlocked page %p", __func__, m));
3409 
3410 	if ((m->aflags & PGA_ENQUEUED) != 0)
3411 		vm_pagequeue_remove(pq, m);
3412 	vm_page_dequeue_complete(m);
3413 	vm_pagequeue_unlock(pq);
3414 }
3415 
3416 /*
3417  * Schedule the given page for insertion into the specified page queue.
3418  * Physical insertion of the page may be deferred indefinitely.
3419  */
3420 static void
3421 vm_page_enqueue(vm_page_t m, uint8_t queue)
3422 {
3423 
3424 	vm_page_assert_locked(m);
3425 	KASSERT(m->queue == PQ_NONE && (m->aflags & PGA_QUEUE_STATE_MASK) == 0,
3426 	    ("%s: page %p is already enqueued", __func__, m));
3427 
3428 	m->queue = queue;
3429 	if ((m->aflags & PGA_REQUEUE) == 0)
3430 		vm_page_aflag_set(m, PGA_REQUEUE);
3431 	vm_page_pqbatch_submit(m, queue);
3432 }
3433 
3434 /*
3435  *	vm_page_requeue:		[ internal use only ]
3436  *
3437  *	Schedule a requeue of the given page.
3438  *
3439  *	The page must be locked.
3440  */
3441 void
3442 vm_page_requeue(vm_page_t m)
3443 {
3444 
3445 	vm_page_assert_locked(m);
3446 	KASSERT(vm_page_queue(m) != PQ_NONE,
3447 	    ("%s: page %p is not logically enqueued", __func__, m));
3448 
3449 	if ((m->aflags & PGA_REQUEUE) == 0)
3450 		vm_page_aflag_set(m, PGA_REQUEUE);
3451 	vm_page_pqbatch_submit(m, atomic_load_8(&m->queue));
3452 }
3453 
3454 /*
3455  *	vm_page_swapqueue:		[ internal use only ]
3456  *
3457  *	Move the page from one queue to another, or to the tail of its
3458  *	current queue, in the face of a possible concurrent call to
3459  *	vm_page_dequeue_deferred_free().
3460  */
3461 void
3462 vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq)
3463 {
3464 	struct vm_pagequeue *pq;
3465 
3466 	KASSERT(oldq < PQ_COUNT && newq < PQ_COUNT && oldq != newq,
3467 	    ("vm_page_swapqueue: invalid queues (%d, %d)", oldq, newq));
3468 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3469 	    ("vm_page_swapqueue: page %p is unmanaged", m));
3470 	vm_page_assert_locked(m);
3471 
3472 	/*
3473 	 * Atomically update the queue field and set PGA_REQUEUE while
3474 	 * ensuring that PGA_DEQUEUE has not been set.
3475 	 */
3476 	pq = &vm_pagequeue_domain(m)->vmd_pagequeues[oldq];
3477 	vm_pagequeue_lock(pq);
3478 	if (!vm_page_pqstate_cmpset(m, oldq, newq, PGA_DEQUEUE, PGA_REQUEUE)) {
3479 		vm_pagequeue_unlock(pq);
3480 		return;
3481 	}
3482 	if ((m->aflags & PGA_ENQUEUED) != 0) {
3483 		vm_pagequeue_remove(pq, m);
3484 		vm_page_aflag_clear(m, PGA_ENQUEUED);
3485 	}
3486 	vm_pagequeue_unlock(pq);
3487 	vm_page_pqbatch_submit(m, newq);
3488 }
3489 
3490 /*
3491  *	vm_page_free_prep:
3492  *
3493  *	Prepares the given page to be put on the free list,
3494  *	disassociating it from any VM object. The caller may return
3495  *	the page to the free list only if this function returns true.
3496  *
3497  *	The object must be locked.  The page must be locked if it is
3498  *	managed.
3499  */
3500 bool
3501 vm_page_free_prep(vm_page_t m)
3502 {
3503 
3504 	/*
3505 	 * Synchronize with threads that have dropped a reference to this
3506 	 * page.
3507 	 */
3508 	atomic_thread_fence_acq();
3509 
3510 #if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP)
3511 	if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) {
3512 		uint64_t *p;
3513 		int i;
3514 		p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
3515 		for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++)
3516 			KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx",
3517 			    m, i, (uintmax_t)*p));
3518 	}
3519 #endif
3520 	if ((m->oflags & VPO_UNMANAGED) == 0)
3521 		KASSERT(!pmap_page_is_mapped(m),
3522 		    ("vm_page_free_prep: freeing mapped page %p", m));
3523 	else
3524 		KASSERT(m->queue == PQ_NONE,
3525 		    ("vm_page_free_prep: unmanaged page %p is queued", m));
3526 	VM_CNT_INC(v_tfree);
3527 
3528 	if (vm_page_sbusied(m))
3529 		panic("vm_page_free_prep: freeing busy page %p", m);
3530 
3531 	if (m->object != NULL) {
3532 		vm_page_object_remove(m);
3533 
3534 		/*
3535 		 * The object reference can be released without an atomic
3536 		 * operation.
3537 		 */
3538 		KASSERT((m->flags & PG_FICTITIOUS) != 0 ||
3539 		    m->ref_count == VPRC_OBJREF,
3540 		    ("vm_page_free_prep: page %p has unexpected ref_count %u",
3541 		    m, m->ref_count));
3542 		m->object = NULL;
3543 		m->ref_count -= VPRC_OBJREF;
3544 	}
3545 
3546 	/*
3547 	 * If fictitious remove object association and
3548 	 * return.
3549 	 */
3550 	if ((m->flags & PG_FICTITIOUS) != 0) {
3551 		KASSERT(m->ref_count == 1,
3552 		    ("fictitious page %p is referenced", m));
3553 		KASSERT(m->queue == PQ_NONE,
3554 		    ("fictitious page %p is queued", m));
3555 		return (false);
3556 	}
3557 
3558 	/*
3559 	 * Pages need not be dequeued before they are returned to the physical
3560 	 * memory allocator, but they must at least be marked for a deferred
3561 	 * dequeue.
3562 	 */
3563 	if ((m->oflags & VPO_UNMANAGED) == 0)
3564 		vm_page_dequeue_deferred_free(m);
3565 
3566 	m->valid = 0;
3567 	vm_page_undirty(m);
3568 
3569 	if (m->ref_count != 0)
3570 		panic("vm_page_free_prep: page %p has references", m);
3571 
3572 	/*
3573 	 * Restore the default memory attribute to the page.
3574 	 */
3575 	if (pmap_page_get_memattr(m) != VM_MEMATTR_DEFAULT)
3576 		pmap_page_set_memattr(m, VM_MEMATTR_DEFAULT);
3577 
3578 #if VM_NRESERVLEVEL > 0
3579 	/*
3580 	 * Determine whether the page belongs to a reservation.  If the page was
3581 	 * allocated from a per-CPU cache, it cannot belong to a reservation, so
3582 	 * as an optimization, we avoid the check in that case.
3583 	 */
3584 	if ((m->flags & PG_PCPU_CACHE) == 0 && vm_reserv_free_page(m))
3585 		return (false);
3586 #endif
3587 
3588 	return (true);
3589 }
3590 
3591 /*
3592  *	vm_page_free_toq:
3593  *
3594  *	Returns the given page to the free list, disassociating it
3595  *	from any VM object.
3596  *
3597  *	The object must be locked.  The page must be locked if it is
3598  *	managed.
3599  */
3600 void
3601 vm_page_free_toq(vm_page_t m)
3602 {
3603 	struct vm_domain *vmd;
3604 	uma_zone_t zone;
3605 
3606 	if (!vm_page_free_prep(m))
3607 		return;
3608 
3609 	vmd = vm_pagequeue_domain(m);
3610 	zone = vmd->vmd_pgcache[m->pool].zone;
3611 	if ((m->flags & PG_PCPU_CACHE) != 0 && zone != NULL) {
3612 		uma_zfree(zone, m);
3613 		return;
3614 	}
3615 	vm_domain_free_lock(vmd);
3616 	vm_phys_free_pages(m, 0);
3617 	vm_domain_free_unlock(vmd);
3618 	vm_domain_freecnt_inc(vmd, 1);
3619 }
3620 
3621 /*
3622  *	vm_page_free_pages_toq:
3623  *
3624  *	Returns a list of pages to the free list, disassociating it
3625  *	from any VM object.  In other words, this is equivalent to
3626  *	calling vm_page_free_toq() for each page of a list of VM objects.
3627  *
3628  *	The objects must be locked.  The pages must be locked if it is
3629  *	managed.
3630  */
3631 void
3632 vm_page_free_pages_toq(struct spglist *free, bool update_wire_count)
3633 {
3634 	vm_page_t m;
3635 	int count;
3636 
3637 	if (SLIST_EMPTY(free))
3638 		return;
3639 
3640 	count = 0;
3641 	while ((m = SLIST_FIRST(free)) != NULL) {
3642 		count++;
3643 		SLIST_REMOVE_HEAD(free, plinks.s.ss);
3644 		vm_page_free_toq(m);
3645 	}
3646 
3647 	if (update_wire_count)
3648 		vm_wire_sub(count);
3649 }
3650 
3651 /*
3652  * Mark this page as wired down, preventing reclamation by the page daemon
3653  * or when the containing object is destroyed.
3654  */
3655 void
3656 vm_page_wire(vm_page_t m)
3657 {
3658 	u_int old;
3659 
3660 	KASSERT(m->object != NULL,
3661 	    ("vm_page_wire: page %p does not belong to an object", m));
3662 	if (!vm_page_busied(m))
3663 		VM_OBJECT_ASSERT_LOCKED(m->object);
3664 	KASSERT((m->flags & PG_FICTITIOUS) == 0 ||
3665 	    VPRC_WIRE_COUNT(m->ref_count) >= 1,
3666 	    ("vm_page_wire: fictitious page %p has zero wirings", m));
3667 
3668 	old = atomic_fetchadd_int(&m->ref_count, 1);
3669 	KASSERT(VPRC_WIRE_COUNT(old) != VPRC_WIRE_COUNT_MAX,
3670 	    ("vm_page_wire: counter overflow for page %p", m));
3671 	if (VPRC_WIRE_COUNT(old) == 0)
3672 		vm_wire_add(1);
3673 }
3674 
3675 /*
3676  * Attempt to wire a mapped page following a pmap lookup of that page.
3677  * This may fail if a thread is concurrently tearing down mappings of the page.
3678  */
3679 bool
3680 vm_page_wire_mapped(vm_page_t m)
3681 {
3682 	u_int old;
3683 
3684 	old = m->ref_count;
3685 	do {
3686 		KASSERT(old > 0,
3687 		    ("vm_page_wire_mapped: wiring unreferenced page %p", m));
3688 		if ((old & VPRC_BLOCKED) != 0)
3689 			return (false);
3690 	} while (!atomic_fcmpset_int(&m->ref_count, &old, old + 1));
3691 
3692 	if (VPRC_WIRE_COUNT(old) == 0)
3693 		vm_wire_add(1);
3694 	return (true);
3695 }
3696 
3697 /*
3698  * Release one wiring of the specified page, potentially allowing it to be
3699  * paged out.
3700  *
3701  * Only managed pages belonging to an object can be paged out.  If the number
3702  * of wirings transitions to zero and the page is eligible for page out, then
3703  * the page is added to the specified paging queue.  If the released wiring
3704  * represented the last reference to the page, the page is freed.
3705  *
3706  * A managed page must be locked.
3707  */
3708 void
3709 vm_page_unwire(vm_page_t m, uint8_t queue)
3710 {
3711 	u_int old;
3712 	bool locked;
3713 
3714 	KASSERT(queue < PQ_COUNT,
3715 	    ("vm_page_unwire: invalid queue %u request for page %p", queue, m));
3716 
3717 	if ((m->oflags & VPO_UNMANAGED) != 0) {
3718 		if (vm_page_unwire_noq(m) && m->ref_count == 0)
3719 			vm_page_free(m);
3720 		return;
3721 	}
3722 
3723 	/*
3724 	 * Update LRU state before releasing the wiring reference.
3725 	 * We only need to do this once since we hold the page lock.
3726 	 * Use a release store when updating the reference count to
3727 	 * synchronize with vm_page_free_prep().
3728 	 */
3729 	old = m->ref_count;
3730 	locked = false;
3731 	do {
3732 		KASSERT(VPRC_WIRE_COUNT(old) > 0,
3733 		    ("vm_page_unwire: wire count underflow for page %p", m));
3734 		if (!locked && VPRC_WIRE_COUNT(old) == 1) {
3735 			vm_page_lock(m);
3736 			locked = true;
3737 			if (queue == PQ_ACTIVE && vm_page_queue(m) == PQ_ACTIVE)
3738 				vm_page_reference(m);
3739 			else
3740 				vm_page_mvqueue(m, queue);
3741 		}
3742 	} while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));
3743 
3744 	/*
3745 	 * Release the lock only after the wiring is released, to ensure that
3746 	 * the page daemon does not encounter and dequeue the page while it is
3747 	 * still wired.
3748 	 */
3749 	if (locked)
3750 		vm_page_unlock(m);
3751 
3752 	if (VPRC_WIRE_COUNT(old) == 1) {
3753 		vm_wire_sub(1);
3754 		if (old == 1)
3755 			vm_page_free(m);
3756 	}
3757 }
3758 
3759 /*
3760  * Unwire a page without (re-)inserting it into a page queue.  It is up
3761  * to the caller to enqueue, requeue, or free the page as appropriate.
3762  * In most cases involving managed pages, vm_page_unwire() should be used
3763  * instead.
3764  */
3765 bool
3766 vm_page_unwire_noq(vm_page_t m)
3767 {
3768 	u_int old;
3769 
3770 	old = vm_page_drop(m, 1);
3771 	KASSERT(VPRC_WIRE_COUNT(old) != 0,
3772 	    ("vm_page_unref: counter underflow for page %p", m));
3773 	KASSERT((m->flags & PG_FICTITIOUS) == 0 || VPRC_WIRE_COUNT(old) > 1,
3774 	    ("vm_page_unref: missing ref on fictitious page %p", m));
3775 
3776 	if (VPRC_WIRE_COUNT(old) > 1)
3777 		return (false);
3778 	vm_wire_sub(1);
3779 	return (true);
3780 }
3781 
3782 /*
3783  * Ensure that the page is in the specified page queue.  If the page is
3784  * active or being moved to the active queue, ensure that its act_count is
3785  * at least ACT_INIT but do not otherwise mess with it.  Otherwise, ensure that
3786  * the page is at the tail of its page queue.
3787  *
3788  * The page may be wired.  The caller should release its wiring reference
3789  * before releasing the page lock, otherwise the page daemon may immediately
3790  * dequeue the page.
3791  *
3792  * A managed page must be locked.
3793  */
3794 static __always_inline void
3795 vm_page_mvqueue(vm_page_t m, const uint8_t nqueue)
3796 {
3797 
3798 	vm_page_assert_locked(m);
3799 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3800 	    ("vm_page_mvqueue: page %p is unmanaged", m));
3801 
3802 	if (vm_page_queue(m) != nqueue) {
3803 		vm_page_dequeue(m);
3804 		vm_page_enqueue(m, nqueue);
3805 	} else if (nqueue != PQ_ACTIVE) {
3806 		vm_page_requeue(m);
3807 	}
3808 
3809 	if (nqueue == PQ_ACTIVE && m->act_count < ACT_INIT)
3810 		m->act_count = ACT_INIT;
3811 }
3812 
3813 /*
3814  * Put the specified page on the active list (if appropriate).
3815  */
3816 void
3817 vm_page_activate(vm_page_t m)
3818 {
3819 
3820 	if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m))
3821 		return;
3822 	vm_page_mvqueue(m, PQ_ACTIVE);
3823 }
3824 
3825 /*
3826  * Move the specified page to the tail of the inactive queue, or requeue
3827  * the page if it is already in the inactive queue.
3828  */
3829 void
3830 vm_page_deactivate(vm_page_t m)
3831 {
3832 
3833 	if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m))
3834 		return;
3835 	vm_page_mvqueue(m, PQ_INACTIVE);
3836 }
3837 
3838 /*
3839  * Move the specified page close to the head of the inactive queue,
3840  * bypassing LRU.  A marker page is used to maintain FIFO ordering.
3841  * As with regular enqueues, we use a per-CPU batch queue to reduce
3842  * contention on the page queue lock.
3843  */
3844 static void
3845 _vm_page_deactivate_noreuse(vm_page_t m)
3846 {
3847 
3848 	vm_page_assert_locked(m);
3849 
3850 	if (!vm_page_inactive(m)) {
3851 		vm_page_dequeue(m);
3852 		m->queue = PQ_INACTIVE;
3853 	}
3854 	if ((m->aflags & PGA_REQUEUE_HEAD) == 0)
3855 		vm_page_aflag_set(m, PGA_REQUEUE_HEAD);
3856 	vm_page_pqbatch_submit(m, PQ_INACTIVE);
3857 }
3858 
3859 void
3860 vm_page_deactivate_noreuse(vm_page_t m)
3861 {
3862 
3863 	KASSERT(m->object != NULL,
3864 	    ("vm_page_deactivate_noreuse: page %p has no object", m));
3865 
3866 	if ((m->oflags & VPO_UNMANAGED) == 0 && !vm_page_wired(m))
3867 		_vm_page_deactivate_noreuse(m);
3868 }
3869 
3870 /*
3871  * Put a page in the laundry, or requeue it if it is already there.
3872  */
3873 void
3874 vm_page_launder(vm_page_t m)
3875 {
3876 
3877 	if ((m->oflags & VPO_UNMANAGED) != 0 || vm_page_wired(m))
3878 		return;
3879 	vm_page_mvqueue(m, PQ_LAUNDRY);
3880 }
3881 
3882 /*
3883  * Put a page in the PQ_UNSWAPPABLE holding queue.
3884  */
3885 void
3886 vm_page_unswappable(vm_page_t m)
3887 {
3888 
3889 	vm_page_assert_locked(m);
3890 	KASSERT(!vm_page_wired(m) && (m->oflags & VPO_UNMANAGED) == 0,
3891 	    ("page %p already unswappable", m));
3892 
3893 	vm_page_dequeue(m);
3894 	vm_page_enqueue(m, PQ_UNSWAPPABLE);
3895 }
3896 
3897 static void
3898 vm_page_release_toq(vm_page_t m, int flags)
3899 {
3900 
3901 	vm_page_assert_locked(m);
3902 
3903 	/*
3904 	 * Use a check of the valid bits to determine whether we should
3905 	 * accelerate reclamation of the page.  The object lock might not be
3906 	 * held here, in which case the check is racy.  At worst we will either
3907 	 * accelerate reclamation of a valid page and violate LRU, or
3908 	 * unnecessarily defer reclamation of an invalid page.
3909 	 *
3910 	 * If we were asked to not cache the page, place it near the head of the
3911 	 * inactive queue so that is reclaimed sooner.
3912 	 */
3913 	if ((flags & (VPR_TRYFREE | VPR_NOREUSE)) != 0 || m->valid == 0)
3914 		_vm_page_deactivate_noreuse(m);
3915 	else if (vm_page_active(m))
3916 		vm_page_reference(m);
3917 	else
3918 		vm_page_mvqueue(m, PQ_INACTIVE);
3919 }
3920 
3921 /*
3922  * Unwire a page and either attempt to free it or re-add it to the page queues.
3923  */
3924 void
3925 vm_page_release(vm_page_t m, int flags)
3926 {
3927 	vm_object_t object;
3928 	u_int old;
3929 	bool locked;
3930 
3931 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3932 	    ("vm_page_release: page %p is unmanaged", m));
3933 
3934 	if ((flags & VPR_TRYFREE) != 0) {
3935 		for (;;) {
3936 			object = (vm_object_t)atomic_load_ptr(&m->object);
3937 			if (object == NULL)
3938 				break;
3939 			/* Depends on type-stability. */
3940 			if (vm_page_busied(m) || !VM_OBJECT_TRYWLOCK(object)) {
3941 				object = NULL;
3942 				break;
3943 			}
3944 			if (object == m->object)
3945 				break;
3946 			VM_OBJECT_WUNLOCK(object);
3947 		}
3948 		if (__predict_true(object != NULL)) {
3949 			vm_page_release_locked(m, flags);
3950 			VM_OBJECT_WUNLOCK(object);
3951 			return;
3952 		}
3953 	}
3954 
3955 	/*
3956 	 * Update LRU state before releasing the wiring reference.
3957 	 * Use a release store when updating the reference count to
3958 	 * synchronize with vm_page_free_prep().
3959 	 */
3960 	old = m->ref_count;
3961 	locked = false;
3962 	do {
3963 		KASSERT(VPRC_WIRE_COUNT(old) > 0,
3964 		    ("vm_page_unwire: wire count underflow for page %p", m));
3965 		if (!locked && VPRC_WIRE_COUNT(old) == 1) {
3966 			vm_page_lock(m);
3967 			locked = true;
3968 			vm_page_release_toq(m, flags);
3969 		}
3970 	} while (!atomic_fcmpset_rel_int(&m->ref_count, &old, old - 1));
3971 
3972 	/*
3973 	 * Release the lock only after the wiring is released, to ensure that
3974 	 * the page daemon does not encounter and dequeue the page while it is
3975 	 * still wired.
3976 	 */
3977 	if (locked)
3978 		vm_page_unlock(m);
3979 
3980 	if (VPRC_WIRE_COUNT(old) == 1) {
3981 		vm_wire_sub(1);
3982 		if (old == 1)
3983 			vm_page_free(m);
3984 	}
3985 }
3986 
3987 /* See vm_page_release(). */
3988 void
3989 vm_page_release_locked(vm_page_t m, int flags)
3990 {
3991 
3992 	VM_OBJECT_ASSERT_WLOCKED(m->object);
3993 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
3994 	    ("vm_page_release_locked: page %p is unmanaged", m));
3995 
3996 	if (vm_page_unwire_noq(m)) {
3997 		if ((flags & VPR_TRYFREE) != 0 &&
3998 		    (m->object->ref_count == 0 || !pmap_page_is_mapped(m)) &&
3999 		    m->dirty == 0 && !vm_page_busied(m)) {
4000 			vm_page_free(m);
4001 		} else {
4002 			vm_page_lock(m);
4003 			vm_page_release_toq(m, flags);
4004 			vm_page_unlock(m);
4005 		}
4006 	}
4007 }
4008 
4009 static bool
4010 vm_page_try_blocked_op(vm_page_t m, void (*op)(vm_page_t))
4011 {
4012 	u_int old;
4013 
4014 	KASSERT(m->object != NULL && (m->oflags & VPO_UNMANAGED) == 0,
4015 	    ("vm_page_try_blocked_op: page %p has no object", m));
4016 	KASSERT(!vm_page_busied(m),
4017 	    ("vm_page_try_blocked_op: page %p is busy", m));
4018 	VM_OBJECT_ASSERT_LOCKED(m->object);
4019 
4020 	old = m->ref_count;
4021 	do {
4022 		KASSERT(old != 0,
4023 		    ("vm_page_try_blocked_op: page %p has no references", m));
4024 		if (VPRC_WIRE_COUNT(old) != 0)
4025 			return (false);
4026 	} while (!atomic_fcmpset_int(&m->ref_count, &old, old | VPRC_BLOCKED));
4027 
4028 	(op)(m);
4029 
4030 	/*
4031 	 * If the object is read-locked, new wirings may be created via an
4032 	 * object lookup.
4033 	 */
4034 	old = vm_page_drop(m, VPRC_BLOCKED);
4035 	KASSERT(!VM_OBJECT_WOWNED(m->object) ||
4036 	    old == (VPRC_BLOCKED | VPRC_OBJREF),
4037 	    ("vm_page_try_blocked_op: unexpected refcount value %u for %p",
4038 	    old, m));
4039 	return (true);
4040 }
4041 
4042 /*
4043  * Atomically check for wirings and remove all mappings of the page.
4044  */
4045 bool
4046 vm_page_try_remove_all(vm_page_t m)
4047 {
4048 
4049 	return (vm_page_try_blocked_op(m, pmap_remove_all));
4050 }
4051 
4052 /*
4053  * Atomically check for wirings and remove all writeable mappings of the page.
4054  */
4055 bool
4056 vm_page_try_remove_write(vm_page_t m)
4057 {
4058 
4059 	return (vm_page_try_blocked_op(m, pmap_remove_write));
4060 }
4061 
4062 /*
4063  * vm_page_advise
4064  *
4065  * 	Apply the specified advice to the given page.
4066  *
4067  *	The object and page must be locked.
4068  */
4069 void
4070 vm_page_advise(vm_page_t m, int advice)
4071 {
4072 
4073 	vm_page_assert_locked(m);
4074 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4075 	if (advice == MADV_FREE)
4076 		/*
4077 		 * Mark the page clean.  This will allow the page to be freed
4078 		 * without first paging it out.  MADV_FREE pages are often
4079 		 * quickly reused by malloc(3), so we do not do anything that
4080 		 * would result in a page fault on a later access.
4081 		 */
4082 		vm_page_undirty(m);
4083 	else if (advice != MADV_DONTNEED) {
4084 		if (advice == MADV_WILLNEED)
4085 			vm_page_activate(m);
4086 		return;
4087 	}
4088 
4089 	/*
4090 	 * Clear any references to the page.  Otherwise, the page daemon will
4091 	 * immediately reactivate the page.
4092 	 */
4093 	vm_page_aflag_clear(m, PGA_REFERENCED);
4094 
4095 	if (advice != MADV_FREE && m->dirty == 0 && pmap_is_modified(m))
4096 		vm_page_dirty(m);
4097 
4098 	/*
4099 	 * Place clean pages near the head of the inactive queue rather than
4100 	 * the tail, thus defeating the queue's LRU operation and ensuring that
4101 	 * the page will be reused quickly.  Dirty pages not already in the
4102 	 * laundry are moved there.
4103 	 */
4104 	if (m->dirty == 0)
4105 		vm_page_deactivate_noreuse(m);
4106 	else if (!vm_page_in_laundry(m))
4107 		vm_page_launder(m);
4108 }
4109 
4110 /*
4111  * Grab a page, waiting until we are waken up due to the page
4112  * changing state.  We keep on waiting, if the page continues
4113  * to be in the object.  If the page doesn't exist, first allocate it
4114  * and then conditionally zero it.
4115  *
4116  * This routine may sleep.
4117  *
4118  * The object must be locked on entry.  The lock will, however, be released
4119  * and reacquired if the routine sleeps.
4120  */
4121 vm_page_t
4122 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
4123 {
4124 	vm_page_t m;
4125 	int sleep;
4126 	int pflags;
4127 
4128 	VM_OBJECT_ASSERT_WLOCKED(object);
4129 	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4130 	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4131 	    ("vm_page_grab: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4132 	pflags = allocflags &
4133 	    ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
4134 	if ((allocflags & VM_ALLOC_NOWAIT) == 0)
4135 		pflags |= VM_ALLOC_WAITFAIL;
4136 retrylookup:
4137 	if ((m = vm_page_lookup(object, pindex)) != NULL) {
4138 		sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
4139 		    vm_page_xbusied(m) : vm_page_busied(m);
4140 		if (sleep) {
4141 			if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4142 				return (NULL);
4143 			/*
4144 			 * Reference the page before unlocking and
4145 			 * sleeping so that the page daemon is less
4146 			 * likely to reclaim it.
4147 			 */
4148 			if ((allocflags & VM_ALLOC_NOCREAT) == 0)
4149 				vm_page_aflag_set(m, PGA_REFERENCED);
4150 			vm_page_busy_sleep(m, "pgrbwt", (allocflags &
4151 			    VM_ALLOC_IGN_SBUSY) != 0);
4152 			VM_OBJECT_WLOCK(object);
4153 			if ((allocflags & VM_ALLOC_WAITFAIL) != 0)
4154 				return (NULL);
4155 			goto retrylookup;
4156 		} else {
4157 			if ((allocflags & VM_ALLOC_WIRED) != 0)
4158 				vm_page_wire(m);
4159 			if ((allocflags &
4160 			    (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
4161 				vm_page_xbusy(m);
4162 			else if ((allocflags & VM_ALLOC_SBUSY) != 0)
4163 				vm_page_sbusy(m);
4164 			return (m);
4165 		}
4166 	}
4167 	if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4168 		return (NULL);
4169 	m = vm_page_alloc(object, pindex, pflags);
4170 	if (m == NULL) {
4171 		if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4172 			return (NULL);
4173 		goto retrylookup;
4174 	}
4175 	if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
4176 		pmap_zero_page(m);
4177 	return (m);
4178 }
4179 
4180 /*
4181  * Grab a page and make it valid, paging in if necessary.  Pages missing from
4182  * their pager are zero filled and validated.
4183  */
4184 int
4185 vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int allocflags)
4186 {
4187 	vm_page_t m;
4188 	bool sleep, xbusy;
4189 	int pflags;
4190 	int rv;
4191 
4192 	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4193 	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4194 	    ("vm_page_grab_valid: VM_ALLOC_SBUSY/VM_ALLOC_IGN_SBUSY mismatch"));
4195 	KASSERT((allocflags &
4196 	    (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
4197 	    ("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
4198 	VM_OBJECT_ASSERT_WLOCKED(object);
4199 	pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY);
4200 	pflags |= VM_ALLOC_WAITFAIL;
4201 
4202 retrylookup:
4203 	xbusy = false;
4204 	if ((m = vm_page_lookup(object, pindex)) != NULL) {
4205 		/*
4206 		 * If the page is fully valid it can only become invalid
4207 		 * with the object lock held.  If it is not valid it can
4208 		 * become valid with the busy lock held.  Therefore, we
4209 		 * may unnecessarily lock the exclusive busy here if we
4210 		 * race with I/O completion not using the object lock.
4211 		 * However, we will not end up with an invalid page and a
4212 		 * shared lock.
4213 		 */
4214 		if (m->valid != VM_PAGE_BITS_ALL ||
4215 		    (allocflags & (VM_ALLOC_IGN_SBUSY | VM_ALLOC_SBUSY)) == 0) {
4216 			sleep = !vm_page_tryxbusy(m);
4217 			xbusy = true;
4218 		} else
4219 			sleep = !vm_page_trysbusy(m);
4220 		if (sleep) {
4221 			/*
4222 			 * Reference the page before unlocking and
4223 			 * sleeping so that the page daemon is less
4224 			 * likely to reclaim it.
4225 			 */
4226 			if ((allocflags & VM_ALLOC_NOCREAT) == 0)
4227 				vm_page_aflag_set(m, PGA_REFERENCED);
4228 			vm_page_busy_sleep(m, "pgrbwt", (allocflags &
4229 			    VM_ALLOC_IGN_SBUSY) != 0);
4230 			VM_OBJECT_WLOCK(object);
4231 			goto retrylookup;
4232 		}
4233 		if ((allocflags & VM_ALLOC_NOCREAT) != 0 &&
4234 		   m->valid != VM_PAGE_BITS_ALL) {
4235 			if (xbusy)
4236 				vm_page_xunbusy(m);
4237 			else
4238 				vm_page_sunbusy(m);
4239 			*mp = NULL;
4240 			return (VM_PAGER_FAIL);
4241 		}
4242 		if ((allocflags & VM_ALLOC_WIRED) != 0)
4243 			vm_page_wire(m);
4244 		if (m->valid == VM_PAGE_BITS_ALL)
4245 			goto out;
4246 	} else if ((allocflags & VM_ALLOC_NOCREAT) != 0) {
4247 		*mp = NULL;
4248 		return (VM_PAGER_FAIL);
4249 	} else if ((m = vm_page_alloc(object, pindex, pflags)) != NULL) {
4250 		xbusy = true;
4251 	} else {
4252 		goto retrylookup;
4253 	}
4254 
4255 	vm_page_assert_xbusied(m);
4256 	MPASS(xbusy);
4257 	if (vm_pager_has_page(object, pindex, NULL, NULL)) {
4258 		rv = vm_pager_get_pages(object, &m, 1, NULL, NULL);
4259 		if (rv != VM_PAGER_OK) {
4260 			if (allocflags & VM_ALLOC_WIRED)
4261 				vm_page_unwire_noq(m);
4262 			vm_page_free(m);
4263 			*mp = NULL;
4264 			return (rv);
4265 		}
4266 		MPASS(m->valid == VM_PAGE_BITS_ALL);
4267 	} else {
4268 		vm_page_zero_invalid(m, TRUE);
4269 	}
4270 out:
4271 	if ((allocflags & VM_ALLOC_NOBUSY) != 0) {
4272 		if (xbusy)
4273 			vm_page_xunbusy(m);
4274 		else
4275 			vm_page_sunbusy(m);
4276 	}
4277 	if ((allocflags & VM_ALLOC_SBUSY) != 0 && xbusy)
4278 		vm_page_busy_downgrade(m);
4279 	*mp = m;
4280 	return (VM_PAGER_OK);
4281 }
4282 
4283 /*
4284  * Return the specified range of pages from the given object.  For each
4285  * page offset within the range, if a page already exists within the object
4286  * at that offset and it is busy, then wait for it to change state.  If,
4287  * instead, the page doesn't exist, then allocate it.
4288  *
4289  * The caller must always specify an allocation class.
4290  *
4291  * allocation classes:
4292  *	VM_ALLOC_NORMAL		normal process request
4293  *	VM_ALLOC_SYSTEM		system *really* needs the pages
4294  *
4295  * The caller must always specify that the pages are to be busied and/or
4296  * wired.
4297  *
4298  * optional allocation flags:
4299  *	VM_ALLOC_IGN_SBUSY	do not sleep on soft busy pages
4300  *	VM_ALLOC_NOBUSY		do not exclusive busy the page
4301  *	VM_ALLOC_NOWAIT		do not sleep
4302  *	VM_ALLOC_SBUSY		set page to sbusy state
4303  *	VM_ALLOC_WIRED		wire the pages
4304  *	VM_ALLOC_ZERO		zero and validate any invalid pages
4305  *
4306  * If VM_ALLOC_NOWAIT is not specified, this routine may sleep.  Otherwise, it
4307  * may return a partial prefix of the requested range.
4308  */
4309 int
4310 vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
4311     vm_page_t *ma, int count)
4312 {
4313 	vm_page_t m, mpred;
4314 	int pflags;
4315 	int i;
4316 	bool sleep;
4317 
4318 	VM_OBJECT_ASSERT_WLOCKED(object);
4319 	KASSERT(((u_int)allocflags >> VM_ALLOC_COUNT_SHIFT) == 0,
4320 	    ("vm_page_grap_pages: VM_ALLOC_COUNT() is not allowed"));
4321 	KASSERT((allocflags & VM_ALLOC_NOBUSY) == 0 ||
4322 	    (allocflags & VM_ALLOC_WIRED) != 0,
4323 	    ("vm_page_grab_pages: the pages must be busied or wired"));
4324 	KASSERT((allocflags & VM_ALLOC_SBUSY) == 0 ||
4325 	    (allocflags & VM_ALLOC_IGN_SBUSY) != 0,
4326 	    ("vm_page_grab_pages: VM_ALLOC_SBUSY/IGN_SBUSY mismatch"));
4327 	if (count == 0)
4328 		return (0);
4329 	pflags = allocflags & ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK |
4330 	    VM_ALLOC_WAITFAIL | VM_ALLOC_IGN_SBUSY);
4331 	if ((allocflags & VM_ALLOC_NOWAIT) == 0)
4332 		pflags |= VM_ALLOC_WAITFAIL;
4333 	i = 0;
4334 retrylookup:
4335 	m = vm_radix_lookup_le(&object->rtree, pindex + i);
4336 	if (m == NULL || m->pindex != pindex + i) {
4337 		mpred = m;
4338 		m = NULL;
4339 	} else
4340 		mpred = TAILQ_PREV(m, pglist, listq);
4341 	for (; i < count; i++) {
4342 		if (m != NULL) {
4343 			sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ?
4344 			    vm_page_xbusied(m) : vm_page_busied(m);
4345 			if (sleep) {
4346 				if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4347 					break;
4348 				/*
4349 				 * Reference the page before unlocking and
4350 				 * sleeping so that the page daemon is less
4351 				 * likely to reclaim it.
4352 				 */
4353 				if ((allocflags & VM_ALLOC_NOCREAT) == 0)
4354 					vm_page_aflag_set(m, PGA_REFERENCED);
4355 				vm_page_busy_sleep(m, "grbmaw", (allocflags &
4356 				    VM_ALLOC_IGN_SBUSY) != 0);
4357 				VM_OBJECT_WLOCK(object);
4358 				goto retrylookup;
4359 			}
4360 			if ((allocflags & VM_ALLOC_WIRED) != 0)
4361 				vm_page_wire(m);
4362 			if ((allocflags & (VM_ALLOC_NOBUSY |
4363 			    VM_ALLOC_SBUSY)) == 0)
4364 				vm_page_xbusy(m);
4365 			if ((allocflags & VM_ALLOC_SBUSY) != 0)
4366 				vm_page_sbusy(m);
4367 		} else {
4368 			if ((allocflags & VM_ALLOC_NOCREAT) != 0)
4369 				break;
4370 			m = vm_page_alloc_after(object, pindex + i,
4371 			    pflags | VM_ALLOC_COUNT(count - i), mpred);
4372 			if (m == NULL) {
4373 				if ((allocflags & VM_ALLOC_NOWAIT) != 0)
4374 					break;
4375 				goto retrylookup;
4376 			}
4377 		}
4378 		if (m->valid == 0 && (allocflags & VM_ALLOC_ZERO) != 0) {
4379 			if ((m->flags & PG_ZERO) == 0)
4380 				pmap_zero_page(m);
4381 			m->valid = VM_PAGE_BITS_ALL;
4382 		}
4383 		ma[i] = mpred = m;
4384 		m = vm_page_next(m);
4385 	}
4386 	return (i);
4387 }
4388 
4389 /*
4390  * Mapping function for valid or dirty bits in a page.
4391  *
4392  * Inputs are required to range within a page.
4393  */
4394 vm_page_bits_t
4395 vm_page_bits(int base, int size)
4396 {
4397 	int first_bit;
4398 	int last_bit;
4399 
4400 	KASSERT(
4401 	    base + size <= PAGE_SIZE,
4402 	    ("vm_page_bits: illegal base/size %d/%d", base, size)
4403 	);
4404 
4405 	if (size == 0)		/* handle degenerate case */
4406 		return (0);
4407 
4408 	first_bit = base >> DEV_BSHIFT;
4409 	last_bit = (base + size - 1) >> DEV_BSHIFT;
4410 
4411 	return (((vm_page_bits_t)2 << last_bit) -
4412 	    ((vm_page_bits_t)1 << first_bit));
4413 }
4414 
4415 /*
4416  *	vm_page_set_valid_range:
4417  *
4418  *	Sets portions of a page valid.  The arguments are expected
4419  *	to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
4420  *	of any partial chunks touched by the range.  The invalid portion of
4421  *	such chunks will be zeroed.
4422  *
4423  *	(base + size) must be less then or equal to PAGE_SIZE.
4424  */
4425 void
4426 vm_page_set_valid_range(vm_page_t m, int base, int size)
4427 {
4428 	int endoff, frag;
4429 
4430 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4431 	if (size == 0)	/* handle degenerate case */
4432 		return;
4433 
4434 	/*
4435 	 * If the base is not DEV_BSIZE aligned and the valid
4436 	 * bit is clear, we have to zero out a portion of the
4437 	 * first block.
4438 	 */
4439 	if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
4440 	    (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
4441 		pmap_zero_page_area(m, frag, base - frag);
4442 
4443 	/*
4444 	 * If the ending offset is not DEV_BSIZE aligned and the
4445 	 * valid bit is clear, we have to zero out a portion of
4446 	 * the last block.
4447 	 */
4448 	endoff = base + size;
4449 	if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
4450 	    (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
4451 		pmap_zero_page_area(m, endoff,
4452 		    DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
4453 
4454 	/*
4455 	 * Assert that no previously invalid block that is now being validated
4456 	 * is already dirty.
4457 	 */
4458 	KASSERT((~m->valid & vm_page_bits(base, size) & m->dirty) == 0,
4459 	    ("vm_page_set_valid_range: page %p is dirty", m));
4460 
4461 	/*
4462 	 * Set valid bits inclusive of any overlap.
4463 	 */
4464 	m->valid |= vm_page_bits(base, size);
4465 }
4466 
4467 /*
4468  * Clear the given bits from the specified page's dirty field.
4469  */
4470 static __inline void
4471 vm_page_clear_dirty_mask(vm_page_t m, vm_page_bits_t pagebits)
4472 {
4473 	uintptr_t addr;
4474 #if PAGE_SIZE < 16384
4475 	int shift;
4476 #endif
4477 
4478 	/*
4479 	 * If the object is locked and the page is neither exclusive busy nor
4480 	 * write mapped, then the page's dirty field cannot possibly be
4481 	 * set by a concurrent pmap operation.
4482 	 */
4483 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4484 	if (!vm_page_xbusied(m) && !pmap_page_is_write_mapped(m))
4485 		m->dirty &= ~pagebits;
4486 	else {
4487 		/*
4488 		 * The pmap layer can call vm_page_dirty() without
4489 		 * holding a distinguished lock.  The combination of
4490 		 * the object's lock and an atomic operation suffice
4491 		 * to guarantee consistency of the page dirty field.
4492 		 *
4493 		 * For PAGE_SIZE == 32768 case, compiler already
4494 		 * properly aligns the dirty field, so no forcible
4495 		 * alignment is needed. Only require existence of
4496 		 * atomic_clear_64 when page size is 32768.
4497 		 */
4498 		addr = (uintptr_t)&m->dirty;
4499 #if PAGE_SIZE == 32768
4500 		atomic_clear_64((uint64_t *)addr, pagebits);
4501 #elif PAGE_SIZE == 16384
4502 		atomic_clear_32((uint32_t *)addr, pagebits);
4503 #else		/* PAGE_SIZE <= 8192 */
4504 		/*
4505 		 * Use a trick to perform a 32-bit atomic on the
4506 		 * containing aligned word, to not depend on the existence
4507 		 * of atomic_clear_{8, 16}.
4508 		 */
4509 		shift = addr & (sizeof(uint32_t) - 1);
4510 #if BYTE_ORDER == BIG_ENDIAN
4511 		shift = (sizeof(uint32_t) - sizeof(m->dirty) - shift) * NBBY;
4512 #else
4513 		shift *= NBBY;
4514 #endif
4515 		addr &= ~(sizeof(uint32_t) - 1);
4516 		atomic_clear_32((uint32_t *)addr, pagebits << shift);
4517 #endif		/* PAGE_SIZE */
4518 	}
4519 }
4520 
4521 /*
4522  *	vm_page_set_validclean:
4523  *
4524  *	Sets portions of a page valid and clean.  The arguments are expected
4525  *	to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
4526  *	of any partial chunks touched by the range.  The invalid portion of
4527  *	such chunks will be zero'd.
4528  *
4529  *	(base + size) must be less then or equal to PAGE_SIZE.
4530  */
4531 void
4532 vm_page_set_validclean(vm_page_t m, int base, int size)
4533 {
4534 	vm_page_bits_t oldvalid, pagebits;
4535 	int endoff, frag;
4536 
4537 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4538 	if (size == 0)	/* handle degenerate case */
4539 		return;
4540 
4541 	/*
4542 	 * If the base is not DEV_BSIZE aligned and the valid
4543 	 * bit is clear, we have to zero out a portion of the
4544 	 * first block.
4545 	 */
4546 	if ((frag = rounddown2(base, DEV_BSIZE)) != base &&
4547 	    (m->valid & ((vm_page_bits_t)1 << (base >> DEV_BSHIFT))) == 0)
4548 		pmap_zero_page_area(m, frag, base - frag);
4549 
4550 	/*
4551 	 * If the ending offset is not DEV_BSIZE aligned and the
4552 	 * valid bit is clear, we have to zero out a portion of
4553 	 * the last block.
4554 	 */
4555 	endoff = base + size;
4556 	if ((frag = rounddown2(endoff, DEV_BSIZE)) != endoff &&
4557 	    (m->valid & ((vm_page_bits_t)1 << (endoff >> DEV_BSHIFT))) == 0)
4558 		pmap_zero_page_area(m, endoff,
4559 		    DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
4560 
4561 	/*
4562 	 * Set valid, clear dirty bits.  If validating the entire
4563 	 * page we can safely clear the pmap modify bit.  We also
4564 	 * use this opportunity to clear the VPO_NOSYNC flag.  If a process
4565 	 * takes a write fault on a MAP_NOSYNC memory area the flag will
4566 	 * be set again.
4567 	 *
4568 	 * We set valid bits inclusive of any overlap, but we can only
4569 	 * clear dirty bits for DEV_BSIZE chunks that are fully within
4570 	 * the range.
4571 	 */
4572 	oldvalid = m->valid;
4573 	pagebits = vm_page_bits(base, size);
4574 	m->valid |= pagebits;
4575 #if 0	/* NOT YET */
4576 	if ((frag = base & (DEV_BSIZE - 1)) != 0) {
4577 		frag = DEV_BSIZE - frag;
4578 		base += frag;
4579 		size -= frag;
4580 		if (size < 0)
4581 			size = 0;
4582 	}
4583 	pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
4584 #endif
4585 	if (base == 0 && size == PAGE_SIZE) {
4586 		/*
4587 		 * The page can only be modified within the pmap if it is
4588 		 * mapped, and it can only be mapped if it was previously
4589 		 * fully valid.
4590 		 */
4591 		if (oldvalid == VM_PAGE_BITS_ALL)
4592 			/*
4593 			 * Perform the pmap_clear_modify() first.  Otherwise,
4594 			 * a concurrent pmap operation, such as
4595 			 * pmap_protect(), could clear a modification in the
4596 			 * pmap and set the dirty field on the page before
4597 			 * pmap_clear_modify() had begun and after the dirty
4598 			 * field was cleared here.
4599 			 */
4600 			pmap_clear_modify(m);
4601 		m->dirty = 0;
4602 		m->oflags &= ~VPO_NOSYNC;
4603 	} else if (oldvalid != VM_PAGE_BITS_ALL)
4604 		m->dirty &= ~pagebits;
4605 	else
4606 		vm_page_clear_dirty_mask(m, pagebits);
4607 }
4608 
4609 void
4610 vm_page_clear_dirty(vm_page_t m, int base, int size)
4611 {
4612 
4613 	vm_page_clear_dirty_mask(m, vm_page_bits(base, size));
4614 }
4615 
4616 /*
4617  *	vm_page_set_invalid:
4618  *
4619  *	Invalidates DEV_BSIZE'd chunks within a page.  Both the
4620  *	valid and dirty bits for the effected areas are cleared.
4621  */
4622 void
4623 vm_page_set_invalid(vm_page_t m, int base, int size)
4624 {
4625 	vm_page_bits_t bits;
4626 	vm_object_t object;
4627 
4628 	object = m->object;
4629 	VM_OBJECT_ASSERT_WLOCKED(object);
4630 	if (object->type == OBJT_VNODE && base == 0 && IDX_TO_OFF(m->pindex) +
4631 	    size >= object->un_pager.vnp.vnp_size)
4632 		bits = VM_PAGE_BITS_ALL;
4633 	else
4634 		bits = vm_page_bits(base, size);
4635 	if (object->ref_count != 0 && m->valid == VM_PAGE_BITS_ALL &&
4636 	    bits != 0)
4637 		pmap_remove_all(m);
4638 	KASSERT((bits == 0 && m->valid == VM_PAGE_BITS_ALL) ||
4639 	    !pmap_page_is_mapped(m),
4640 	    ("vm_page_set_invalid: page %p is mapped", m));
4641 	m->valid &= ~bits;
4642 	m->dirty &= ~bits;
4643 }
4644 
4645 /*
4646  * vm_page_zero_invalid()
4647  *
4648  *	The kernel assumes that the invalid portions of a page contain
4649  *	garbage, but such pages can be mapped into memory by user code.
4650  *	When this occurs, we must zero out the non-valid portions of the
4651  *	page so user code sees what it expects.
4652  *
4653  *	Pages are most often semi-valid when the end of a file is mapped
4654  *	into memory and the file's size is not page aligned.
4655  */
4656 void
4657 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
4658 {
4659 	int b;
4660 	int i;
4661 
4662 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4663 	/*
4664 	 * Scan the valid bits looking for invalid sections that
4665 	 * must be zeroed.  Invalid sub-DEV_BSIZE'd areas ( where the
4666 	 * valid bit may be set ) have already been zeroed by
4667 	 * vm_page_set_validclean().
4668 	 */
4669 	for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
4670 		if (i == (PAGE_SIZE / DEV_BSIZE) ||
4671 		    (m->valid & ((vm_page_bits_t)1 << i))) {
4672 			if (i > b) {
4673 				pmap_zero_page_area(m,
4674 				    b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
4675 			}
4676 			b = i + 1;
4677 		}
4678 	}
4679 
4680 	/*
4681 	 * setvalid is TRUE when we can safely set the zero'd areas
4682 	 * as being valid.  We can do this if there are no cache consistancy
4683 	 * issues.  e.g. it is ok to do with UFS, but not ok to do with NFS.
4684 	 */
4685 	if (setvalid)
4686 		m->valid = VM_PAGE_BITS_ALL;
4687 }
4688 
4689 /*
4690  *	vm_page_is_valid:
4691  *
4692  *	Is (partial) page valid?  Note that the case where size == 0
4693  *	will return FALSE in the degenerate case where the page is
4694  *	entirely invalid, and TRUE otherwise.
4695  */
4696 int
4697 vm_page_is_valid(vm_page_t m, int base, int size)
4698 {
4699 	vm_page_bits_t bits;
4700 
4701 	VM_OBJECT_ASSERT_LOCKED(m->object);
4702 	bits = vm_page_bits(base, size);
4703 	return (m->valid != 0 && (m->valid & bits) == bits);
4704 }
4705 
4706 /*
4707  * Returns true if all of the specified predicates are true for the entire
4708  * (super)page and false otherwise.
4709  */
4710 bool
4711 vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m)
4712 {
4713 	vm_object_t object;
4714 	int i, npages;
4715 
4716 	object = m->object;
4717 	if (skip_m != NULL && skip_m->object != object)
4718 		return (false);
4719 	VM_OBJECT_ASSERT_LOCKED(object);
4720 	npages = atop(pagesizes[m->psind]);
4721 
4722 	/*
4723 	 * The physically contiguous pages that make up a superpage, i.e., a
4724 	 * page with a page size index ("psind") greater than zero, will
4725 	 * occupy adjacent entries in vm_page_array[].
4726 	 */
4727 	for (i = 0; i < npages; i++) {
4728 		/* Always test object consistency, including "skip_m". */
4729 		if (m[i].object != object)
4730 			return (false);
4731 		if (&m[i] == skip_m)
4732 			continue;
4733 		if ((flags & PS_NONE_BUSY) != 0 && vm_page_busied(&m[i]))
4734 			return (false);
4735 		if ((flags & PS_ALL_DIRTY) != 0) {
4736 			/*
4737 			 * Calling vm_page_test_dirty() or pmap_is_modified()
4738 			 * might stop this case from spuriously returning
4739 			 * "false".  However, that would require a write lock
4740 			 * on the object containing "m[i]".
4741 			 */
4742 			if (m[i].dirty != VM_PAGE_BITS_ALL)
4743 				return (false);
4744 		}
4745 		if ((flags & PS_ALL_VALID) != 0 &&
4746 		    m[i].valid != VM_PAGE_BITS_ALL)
4747 			return (false);
4748 	}
4749 	return (true);
4750 }
4751 
4752 /*
4753  * Set the page's dirty bits if the page is modified.
4754  */
4755 void
4756 vm_page_test_dirty(vm_page_t m)
4757 {
4758 
4759 	VM_OBJECT_ASSERT_WLOCKED(m->object);
4760 	if (m->dirty != VM_PAGE_BITS_ALL && pmap_is_modified(m))
4761 		vm_page_dirty(m);
4762 }
4763 
4764 void
4765 vm_page_lock_KBI(vm_page_t m, const char *file, int line)
4766 {
4767 
4768 	mtx_lock_flags_(vm_page_lockptr(m), 0, file, line);
4769 }
4770 
4771 void
4772 vm_page_unlock_KBI(vm_page_t m, const char *file, int line)
4773 {
4774 
4775 	mtx_unlock_flags_(vm_page_lockptr(m), 0, file, line);
4776 }
4777 
4778 int
4779 vm_page_trylock_KBI(vm_page_t m, const char *file, int line)
4780 {
4781 
4782 	return (mtx_trylock_flags_(vm_page_lockptr(m), 0, file, line));
4783 }
4784 
4785 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
4786 void
4787 vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line)
4788 {
4789 
4790 	vm_page_lock_assert_KBI(m, MA_OWNED, file, line);
4791 }
4792 
4793 void
4794 vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line)
4795 {
4796 
4797 	mtx_assert_(vm_page_lockptr(m), a, file, line);
4798 }
4799 #endif
4800 
4801 #ifdef INVARIANTS
4802 void
4803 vm_page_object_lock_assert(vm_page_t m)
4804 {
4805 
4806 	/*
4807 	 * Certain of the page's fields may only be modified by the
4808 	 * holder of the containing object's lock or the exclusive busy.
4809 	 * holder.  Unfortunately, the holder of the write busy is
4810 	 * not recorded, and thus cannot be checked here.
4811 	 */
4812 	if (m->object != NULL && !vm_page_xbusied(m))
4813 		VM_OBJECT_ASSERT_WLOCKED(m->object);
4814 }
4815 
4816 void
4817 vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits)
4818 {
4819 
4820 	if ((bits & PGA_WRITEABLE) == 0)
4821 		return;
4822 
4823 	/*
4824 	 * The PGA_WRITEABLE flag can only be set if the page is
4825 	 * managed, is exclusively busied or the object is locked.
4826 	 * Currently, this flag is only set by pmap_enter().
4827 	 */
4828 	KASSERT((m->oflags & VPO_UNMANAGED) == 0,
4829 	    ("PGA_WRITEABLE on unmanaged page"));
4830 	if (!vm_page_xbusied(m))
4831 		VM_OBJECT_ASSERT_LOCKED(m->object);
4832 }
4833 #endif
4834 
4835 #include "opt_ddb.h"
4836 #ifdef DDB
4837 #include <sys/kernel.h>
4838 
4839 #include <ddb/ddb.h>
4840 
4841 DB_SHOW_COMMAND(page, vm_page_print_page_info)
4842 {
4843 
4844 	db_printf("vm_cnt.v_free_count: %d\n", vm_free_count());
4845 	db_printf("vm_cnt.v_inactive_count: %d\n", vm_inactive_count());
4846 	db_printf("vm_cnt.v_active_count: %d\n", vm_active_count());
4847 	db_printf("vm_cnt.v_laundry_count: %d\n", vm_laundry_count());
4848 	db_printf("vm_cnt.v_wire_count: %d\n", vm_wire_count());
4849 	db_printf("vm_cnt.v_free_reserved: %d\n", vm_cnt.v_free_reserved);
4850 	db_printf("vm_cnt.v_free_min: %d\n", vm_cnt.v_free_min);
4851 	db_printf("vm_cnt.v_free_target: %d\n", vm_cnt.v_free_target);
4852 	db_printf("vm_cnt.v_inactive_target: %d\n", vm_cnt.v_inactive_target);
4853 }
4854 
4855 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
4856 {
4857 	int dom;
4858 
4859 	db_printf("pq_free %d\n", vm_free_count());
4860 	for (dom = 0; dom < vm_ndomains; dom++) {
4861 		db_printf(
4862     "dom %d page_cnt %d free %d pq_act %d pq_inact %d pq_laund %d pq_unsw %d\n",
4863 		    dom,
4864 		    vm_dom[dom].vmd_page_count,
4865 		    vm_dom[dom].vmd_free_count,
4866 		    vm_dom[dom].vmd_pagequeues[PQ_ACTIVE].pq_cnt,
4867 		    vm_dom[dom].vmd_pagequeues[PQ_INACTIVE].pq_cnt,
4868 		    vm_dom[dom].vmd_pagequeues[PQ_LAUNDRY].pq_cnt,
4869 		    vm_dom[dom].vmd_pagequeues[PQ_UNSWAPPABLE].pq_cnt);
4870 	}
4871 }
4872 
4873 DB_SHOW_COMMAND(pginfo, vm_page_print_pginfo)
4874 {
4875 	vm_page_t m;
4876 	boolean_t phys, virt;
4877 
4878 	if (!have_addr) {
4879 		db_printf("show pginfo addr\n");
4880 		return;
4881 	}
4882 
4883 	phys = strchr(modif, 'p') != NULL;
4884 	virt = strchr(modif, 'v') != NULL;
4885 	if (virt)
4886 		m = PHYS_TO_VM_PAGE(pmap_kextract(addr));
4887 	else if (phys)
4888 		m = PHYS_TO_VM_PAGE(addr);
4889 	else
4890 		m = (vm_page_t)addr;
4891 	db_printf(
4892     "page %p obj %p pidx 0x%jx phys 0x%jx q %d ref %u\n"
4893     "  af 0x%x of 0x%x f 0x%x act %d busy %x valid 0x%x dirty 0x%x\n",
4894 	    m, m->object, (uintmax_t)m->pindex, (uintmax_t)m->phys_addr,
4895 	    m->queue, m->ref_count, m->aflags, m->oflags,
4896 	    m->flags, m->act_count, m->busy_lock, m->valid, m->dirty);
4897 }
4898 #endif /* DDB */
4899