FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_page.c
1 /*-
2 * Copyright (c) 1991 Regents of the University of California.
3 * All rights reserved.
4 * Copyright (c) 1998 Matthew Dillon. All Rights Reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * The Mach Operating System project at Carnegie-Mellon University.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
34 */
35
36 /*-
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
39 *
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
41 *
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
47 *
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 *
52 * Carnegie Mellon requests users of this software to return to
53 *
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
58 *
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
61 */
62
63 /*
64 * GENERAL RULES ON VM_PAGE MANIPULATION
65 *
66 * - a pageq mutex is required when adding or removing a page from a
67 * page queue (vm_page_queue[]), regardless of other mutexes or the
68 * busy state of a page.
69 *
70 * - a hash chain mutex is required when associating or disassociating
71 * a page from the VM PAGE CACHE hash table (vm_page_buckets),
72 * regardless of other mutexes or the busy state of a page.
73 *
74 * - either a hash chain mutex OR a busied page is required in order
75 * to modify the page flags. A hash chain mutex must be obtained in
76 * order to busy a page. A page's flags cannot be modified by a
77 * hash chain mutex if the page is marked busy.
78 *
79 * - The object memq mutex is held when inserting or removing
80 * pages from an object (vm_page_insert() or vm_page_remove()). This
81 * is different from the object's main mutex.
82 *
83 * Generally speaking, you have to be aware of side effects when running
84 * vm_page ops. A vm_page_lookup() will return with the hash chain
85 * locked, whether it was able to lookup the page or not. vm_page_free(),
86 * vm_page_cache(), vm_page_activate(), and a number of other routines
87 * will release the hash chain mutex for you. Intermediate manipulation
88 * routines such as vm_page_flag_set() expect the hash chain to be held
89 * on entry and the hash chain will remain held on return.
90 *
91 * pageq scanning can only occur with the pageq in question locked.
92 * We have a known bottleneck with the active queue, but the cache
93 * and free queues are actually arrays already.
94 */
95
96 /*
97 * Resident memory management module.
98 */
99
100 #include <sys/cdefs.h>
101 __FBSDID("$FreeBSD$");
102
103 #include "opt_vm.h"
104
105 #include <sys/param.h>
106 #include <sys/systm.h>
107 #include <sys/lock.h>
108 #include <sys/kernel.h>
109 #include <sys/limits.h>
110 #include <sys/malloc.h>
111 #include <sys/mutex.h>
112 #include <sys/proc.h>
113 #include <sys/sysctl.h>
114 #include <sys/vmmeter.h>
115 #include <sys/vnode.h>
116
117 #include <vm/vm.h>
118 #include <vm/vm_param.h>
119 #include <vm/vm_kern.h>
120 #include <vm/vm_object.h>
121 #include <vm/vm_page.h>
122 #include <vm/vm_pageout.h>
123 #include <vm/vm_pager.h>
124 #include <vm/vm_phys.h>
125 #include <vm/vm_reserv.h>
126 #include <vm/vm_extern.h>
127 #include <vm/uma.h>
128 #include <vm/uma_int.h>
129
130 #include <machine/md_var.h>
131
132 /*
133 * Associated with page of user-allocatable memory is a
134 * page structure.
135 */
136
137 struct vpgqueues vm_page_queues[PQ_COUNT];
138 struct mtx vm_page_queue_mtx;
139 struct mtx vm_page_queue_free_mtx;
140
141 vm_page_t vm_page_array = 0;
142 int vm_page_array_size = 0;
143 long first_page = 0;
144 int vm_page_zero_count = 0;
145
146 static int boot_pages = UMA_BOOT_PAGES;
147 TUNABLE_INT("vm.boot_pages", &boot_pages);
148 SYSCTL_INT(_vm, OID_AUTO, boot_pages, CTLFLAG_RD, &boot_pages, 0,
149 "number of pages allocated for bootstrapping the VM system");
150
151 static void vm_page_enqueue(int queue, vm_page_t m);
152
153 /*
154 * vm_set_page_size:
155 *
156 * Sets the page size, perhaps based upon the memory
157 * size. Must be called before any use of page-size
158 * dependent functions.
159 */
160 void
161 vm_set_page_size(void)
162 {
163 if (cnt.v_page_size == 0)
164 cnt.v_page_size = PAGE_SIZE;
165 if (((cnt.v_page_size - 1) & cnt.v_page_size) != 0)
166 panic("vm_set_page_size: page size not a power of two");
167 }
168
169 /*
170 * vm_page_blacklist_lookup:
171 *
172 * See if a physical address in this page has been listed
173 * in the blacklist tunable. Entries in the tunable are
174 * separated by spaces or commas. If an invalid integer is
175 * encountered then the rest of the string is skipped.
176 */
177 static int
178 vm_page_blacklist_lookup(char *list, vm_paddr_t pa)
179 {
180 vm_paddr_t bad;
181 char *cp, *pos;
182
183 for (pos = list; *pos != '\0'; pos = cp) {
184 bad = strtoq(pos, &cp, 0);
185 if (*cp != '\0') {
186 if (*cp == ' ' || *cp == ',') {
187 cp++;
188 if (cp == pos)
189 continue;
190 } else
191 break;
192 }
193 if (pa == trunc_page(bad))
194 return (1);
195 }
196 return (0);
197 }
198
199 /*
200 * vm_page_startup:
201 *
202 * Initializes the resident memory module.
203 *
204 * Allocates memory for the page cells, and
205 * for the object/offset-to-page hash table headers.
206 * Each page cell is initialized and placed on the free list.
207 */
208 vm_offset_t
209 vm_page_startup(vm_offset_t vaddr)
210 {
211 vm_offset_t mapped;
212 vm_paddr_t page_range;
213 vm_paddr_t new_end;
214 int i;
215 vm_paddr_t pa;
216 int nblocks;
217 vm_paddr_t last_pa;
218 char *list;
219
220 /* the biggest memory array is the second group of pages */
221 vm_paddr_t end;
222 vm_paddr_t biggestsize;
223 vm_paddr_t low_water, high_water;
224 int biggestone;
225
226 biggestsize = 0;
227 biggestone = 0;
228 nblocks = 0;
229 vaddr = round_page(vaddr);
230
231 for (i = 0; phys_avail[i + 1]; i += 2) {
232 phys_avail[i] = round_page(phys_avail[i]);
233 phys_avail[i + 1] = trunc_page(phys_avail[i + 1]);
234 }
235
236 low_water = phys_avail[0];
237 high_water = phys_avail[1];
238
239 for (i = 0; phys_avail[i + 1]; i += 2) {
240 vm_paddr_t size = phys_avail[i + 1] - phys_avail[i];
241
242 if (size > biggestsize) {
243 biggestone = i;
244 biggestsize = size;
245 }
246 if (phys_avail[i] < low_water)
247 low_water = phys_avail[i];
248 if (phys_avail[i + 1] > high_water)
249 high_water = phys_avail[i + 1];
250 ++nblocks;
251 }
252
253 end = phys_avail[biggestone+1];
254
255 /*
256 * Initialize the locks.
257 */
258 mtx_init(&vm_page_queue_mtx, "vm page queue mutex", NULL, MTX_DEF |
259 MTX_RECURSE);
260 mtx_init(&vm_page_queue_free_mtx, "vm page queue free mutex", NULL,
261 MTX_DEF);
262
263 /*
264 * Initialize the queue headers for the free queue, the active queue
265 * and the inactive queue.
266 */
267 for (i = 0; i < PQ_COUNT; i++)
268 TAILQ_INIT(&vm_page_queues[i].pl);
269 vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count;
270 vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count;
271 vm_page_queues[PQ_HOLD].cnt = &cnt.v_active_count;
272
273 /*
274 * Allocate memory for use when boot strapping the kernel memory
275 * allocator.
276 */
277 new_end = end - (boot_pages * UMA_SLAB_SIZE);
278 new_end = trunc_page(new_end);
279 mapped = pmap_map(&vaddr, new_end, end,
280 VM_PROT_READ | VM_PROT_WRITE);
281 bzero((void *)mapped, end - new_end);
282 uma_startup((void *)mapped, boot_pages);
283
284 #if defined(__amd64__) || defined(__i386__)
285 /*
286 * Allocate a bitmap to indicate that a random physical page
287 * needs to be included in a minidump.
288 *
289 * The amd64 port needs this to indicate which direct map pages
290 * need to be dumped, via calls to dump_add_page()/dump_drop_page().
291 *
292 * However, i386 still needs this workspace internally within the
293 * minidump code. In theory, they are not needed on i386, but are
294 * included should the sf_buf code decide to use them.
295 */
296 page_range = phys_avail[(nblocks - 1) * 2 + 1] / PAGE_SIZE;
297 vm_page_dump_size = round_page(roundup2(page_range, NBBY) / NBBY);
298 new_end -= vm_page_dump_size;
299 vm_page_dump = (void *)(uintptr_t)pmap_map(&vaddr, new_end,
300 new_end + vm_page_dump_size, VM_PROT_READ | VM_PROT_WRITE);
301 bzero((void *)vm_page_dump, vm_page_dump_size);
302 #endif
303 /*
304 * Compute the number of pages of memory that will be available for
305 * use (taking into account the overhead of a page structure per
306 * page).
307 */
308 first_page = low_water / PAGE_SIZE;
309 #ifdef VM_PHYSSEG_SPARSE
310 page_range = 0;
311 for (i = 0; phys_avail[i + 1] != 0; i += 2)
312 page_range += atop(phys_avail[i + 1] - phys_avail[i]);
313 #elif defined(VM_PHYSSEG_DENSE)
314 page_range = high_water / PAGE_SIZE - first_page;
315 #else
316 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
317 #endif
318 end = new_end;
319
320 /*
321 * Reserve an unmapped guard page to trap access to vm_page_array[-1].
322 */
323 vaddr += PAGE_SIZE;
324
325 /*
326 * Initialize the mem entry structures now, and put them in the free
327 * queue.
328 */
329 new_end = trunc_page(end - page_range * sizeof(struct vm_page));
330 mapped = pmap_map(&vaddr, new_end, end,
331 VM_PROT_READ | VM_PROT_WRITE);
332 vm_page_array = (vm_page_t) mapped;
333 #if VM_NRESERVLEVEL > 0
334 /*
335 * Allocate memory for the reservation management system's data
336 * structures.
337 */
338 new_end = vm_reserv_startup(&vaddr, new_end, high_water);
339 #endif
340 #ifdef __amd64__
341 /*
342 * pmap_map on amd64 comes out of the direct-map, not kvm like i386,
343 * so the pages must be tracked for a crashdump to include this data.
344 * This includes the vm_page_array and the early UMA bootstrap pages.
345 */
346 for (pa = new_end; pa < phys_avail[biggestone + 1]; pa += PAGE_SIZE)
347 dump_add_page(pa);
348 #endif
349 phys_avail[biggestone + 1] = new_end;
350
351 /*
352 * Clear all of the page structures
353 */
354 bzero((caddr_t) vm_page_array, page_range * sizeof(struct vm_page));
355 for (i = 0; i < page_range; i++)
356 vm_page_array[i].order = VM_NFREEORDER;
357 vm_page_array_size = page_range;
358
359 /*
360 * Initialize the physical memory allocator.
361 */
362 vm_phys_init();
363
364 /*
365 * Add every available physical page that is not blacklisted to
366 * the free lists.
367 */
368 cnt.v_page_count = 0;
369 cnt.v_free_count = 0;
370 list = getenv("vm.blacklist");
371 for (i = 0; phys_avail[i + 1] != 0; i += 2) {
372 pa = phys_avail[i];
373 last_pa = phys_avail[i + 1];
374 while (pa < last_pa) {
375 if (list != NULL &&
376 vm_page_blacklist_lookup(list, pa))
377 printf("Skipping page with pa 0x%jx\n",
378 (uintmax_t)pa);
379 else
380 vm_phys_add_page(pa);
381 pa += PAGE_SIZE;
382 }
383 }
384 freeenv(list);
385 #if VM_NRESERVLEVEL > 0
386 /*
387 * Initialize the reservation management system.
388 */
389 vm_reserv_init();
390 #endif
391 return (vaddr);
392 }
393
394 void
395 vm_page_flag_set(vm_page_t m, unsigned short bits)
396 {
397
398 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
399 m->flags |= bits;
400 }
401
402 void
403 vm_page_flag_clear(vm_page_t m, unsigned short bits)
404 {
405
406 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
407 m->flags &= ~bits;
408 }
409
410 void
411 vm_page_busy(vm_page_t m)
412 {
413
414 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
415 KASSERT((m->oflags & VPO_BUSY) == 0,
416 ("vm_page_busy: page already busy!!!"));
417 m->oflags |= VPO_BUSY;
418 }
419
420 /*
421 * vm_page_flash:
422 *
423 * wakeup anyone waiting for the page.
424 */
425 void
426 vm_page_flash(vm_page_t m)
427 {
428
429 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
430 if (m->oflags & VPO_WANTED) {
431 m->oflags &= ~VPO_WANTED;
432 wakeup(m);
433 }
434 }
435
436 /*
437 * vm_page_wakeup:
438 *
439 * clear the VPO_BUSY flag and wakeup anyone waiting for the
440 * page.
441 *
442 */
443 void
444 vm_page_wakeup(vm_page_t m)
445 {
446
447 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
448 KASSERT(m->oflags & VPO_BUSY, ("vm_page_wakeup: page not busy!!!"));
449 m->oflags &= ~VPO_BUSY;
450 vm_page_flash(m);
451 }
452
453 void
454 vm_page_io_start(vm_page_t m)
455 {
456
457 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
458 m->busy++;
459 }
460
461 void
462 vm_page_io_finish(vm_page_t m)
463 {
464
465 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
466 m->busy--;
467 if (m->busy == 0)
468 vm_page_flash(m);
469 }
470
471 /*
472 * Keep page from being freed by the page daemon
473 * much of the same effect as wiring, except much lower
474 * overhead and should be used only for *very* temporary
475 * holding ("wiring").
476 */
477 void
478 vm_page_hold(vm_page_t mem)
479 {
480
481 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
482 mem->hold_count++;
483 }
484
485 void
486 vm_page_unhold(vm_page_t mem)
487 {
488
489 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
490 --mem->hold_count;
491 KASSERT(mem->hold_count >= 0, ("vm_page_unhold: hold count < 0!!!"));
492 if (mem->hold_count == 0 && VM_PAGE_INQUEUE2(mem, PQ_HOLD))
493 vm_page_free_toq(mem);
494 }
495
496 /*
497 * vm_page_free:
498 *
499 * Free a page.
500 */
501 void
502 vm_page_free(vm_page_t m)
503 {
504
505 m->flags &= ~PG_ZERO;
506 vm_page_free_toq(m);
507 }
508
509 /*
510 * vm_page_free_zero:
511 *
512 * Free a page to the zerod-pages queue
513 */
514 void
515 vm_page_free_zero(vm_page_t m)
516 {
517
518 m->flags |= PG_ZERO;
519 vm_page_free_toq(m);
520 }
521
522 /*
523 * vm_page_sleep:
524 *
525 * Sleep and release the page queues lock.
526 *
527 * The object containing the given page must be locked.
528 */
529 void
530 vm_page_sleep(vm_page_t m, const char *msg)
531 {
532
533 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
534 if (!mtx_owned(&vm_page_queue_mtx))
535 vm_page_lock_queues();
536 vm_page_flag_set(m, PG_REFERENCED);
537 vm_page_unlock_queues();
538
539 /*
540 * It's possible that while we sleep, the page will get
541 * unbusied and freed. If we are holding the object
542 * lock, we will assume we hold a reference to the object
543 * such that even if m->object changes, we can re-lock
544 * it.
545 */
546 m->oflags |= VPO_WANTED;
547 msleep(m, VM_OBJECT_MTX(m->object), PVM, msg, 0);
548 }
549
550 /*
551 * vm_page_dirty:
552 *
553 * make page all dirty
554 */
555 void
556 vm_page_dirty(vm_page_t m)
557 {
558 KASSERT((m->flags & PG_CACHED) == 0,
559 ("vm_page_dirty: page in cache!"));
560 KASSERT(!VM_PAGE_IS_FREE(m),
561 ("vm_page_dirty: page is free!"));
562 m->dirty = VM_PAGE_BITS_ALL;
563 }
564
565 /*
566 * vm_page_splay:
567 *
568 * Implements Sleator and Tarjan's top-down splay algorithm. Returns
569 * the vm_page containing the given pindex. If, however, that
570 * pindex is not found in the vm_object, returns a vm_page that is
571 * adjacent to the pindex, coming before or after it.
572 */
573 vm_page_t
574 vm_page_splay(vm_pindex_t pindex, vm_page_t root)
575 {
576 struct vm_page dummy;
577 vm_page_t lefttreemax, righttreemin, y;
578
579 if (root == NULL)
580 return (root);
581 lefttreemax = righttreemin = &dummy;
582 for (;; root = y) {
583 if (pindex < root->pindex) {
584 if ((y = root->left) == NULL)
585 break;
586 if (pindex < y->pindex) {
587 /* Rotate right. */
588 root->left = y->right;
589 y->right = root;
590 root = y;
591 if ((y = root->left) == NULL)
592 break;
593 }
594 /* Link into the new root's right tree. */
595 righttreemin->left = root;
596 righttreemin = root;
597 } else if (pindex > root->pindex) {
598 if ((y = root->right) == NULL)
599 break;
600 if (pindex > y->pindex) {
601 /* Rotate left. */
602 root->right = y->left;
603 y->left = root;
604 root = y;
605 if ((y = root->right) == NULL)
606 break;
607 }
608 /* Link into the new root's left tree. */
609 lefttreemax->right = root;
610 lefttreemax = root;
611 } else
612 break;
613 }
614 /* Assemble the new root. */
615 lefttreemax->right = root->left;
616 righttreemin->left = root->right;
617 root->left = dummy.right;
618 root->right = dummy.left;
619 return (root);
620 }
621
622 /*
623 * vm_page_insert: [ internal use only ]
624 *
625 * Inserts the given mem entry into the object and object list.
626 *
627 * The pagetables are not updated but will presumably fault the page
628 * in if necessary, or if a kernel page the caller will at some point
629 * enter the page into the kernel's pmap. We are not allowed to block
630 * here so we *can't* do this anyway.
631 *
632 * The object and page must be locked.
633 * This routine may not block.
634 */
635 void
636 vm_page_insert(vm_page_t m, vm_object_t object, vm_pindex_t pindex)
637 {
638 vm_page_t root;
639
640 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
641 if (m->object != NULL)
642 panic("vm_page_insert: page already inserted");
643
644 /*
645 * Record the object/offset pair in this page
646 */
647 m->object = object;
648 m->pindex = pindex;
649
650 /*
651 * Now link into the object's ordered list of backed pages.
652 */
653 root = object->root;
654 if (root == NULL) {
655 m->left = NULL;
656 m->right = NULL;
657 TAILQ_INSERT_TAIL(&object->memq, m, listq);
658 } else {
659 root = vm_page_splay(pindex, root);
660 if (pindex < root->pindex) {
661 m->left = root->left;
662 m->right = root;
663 root->left = NULL;
664 TAILQ_INSERT_BEFORE(root, m, listq);
665 } else if (pindex == root->pindex)
666 panic("vm_page_insert: offset already allocated");
667 else {
668 m->right = root->right;
669 m->left = root;
670 root->right = NULL;
671 TAILQ_INSERT_AFTER(&object->memq, root, m, listq);
672 }
673 }
674 object->root = m;
675 object->generation++;
676
677 /*
678 * show that the object has one more resident page.
679 */
680 object->resident_page_count++;
681 /*
682 * Hold the vnode until the last page is released.
683 */
684 if (object->resident_page_count == 1 && object->type == OBJT_VNODE)
685 vhold((struct vnode *)object->handle);
686
687 /*
688 * Since we are inserting a new and possibly dirty page,
689 * update the object's OBJ_MIGHTBEDIRTY flag.
690 */
691 if (m->flags & PG_WRITEABLE)
692 vm_object_set_writeable_dirty(object);
693 }
694
695 /*
696 * vm_page_remove:
697 * NOTE: used by device pager as well -wfj
698 *
699 * Removes the given mem entry from the object/offset-page
700 * table and the object page list, but do not invalidate/terminate
701 * the backing store.
702 *
703 * The object and page must be locked.
704 * The underlying pmap entry (if any) is NOT removed here.
705 * This routine may not block.
706 */
707 void
708 vm_page_remove(vm_page_t m)
709 {
710 vm_object_t object;
711 vm_page_t root;
712
713 if ((object = m->object) == NULL)
714 return;
715 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
716 if (m->oflags & VPO_BUSY) {
717 m->oflags &= ~VPO_BUSY;
718 vm_page_flash(m);
719 }
720 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
721
722 /*
723 * Now remove from the object's list of backed pages.
724 */
725 if (m != object->root)
726 vm_page_splay(m->pindex, object->root);
727 if (m->left == NULL)
728 root = m->right;
729 else {
730 root = vm_page_splay(m->pindex, m->left);
731 root->right = m->right;
732 }
733 object->root = root;
734 TAILQ_REMOVE(&object->memq, m, listq);
735
736 /*
737 * And show that the object has one fewer resident page.
738 */
739 object->resident_page_count--;
740 object->generation++;
741 /*
742 * The vnode may now be recycled.
743 */
744 if (object->resident_page_count == 0 && object->type == OBJT_VNODE)
745 vdrop((struct vnode *)object->handle);
746
747 m->object = NULL;
748 }
749
750 /*
751 * vm_page_lookup:
752 *
753 * Returns the page associated with the object/offset
754 * pair specified; if none is found, NULL is returned.
755 *
756 * The object must be locked.
757 * This routine may not block.
758 * This is a critical path routine
759 */
760 vm_page_t
761 vm_page_lookup(vm_object_t object, vm_pindex_t pindex)
762 {
763 vm_page_t m;
764
765 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
766 if ((m = object->root) != NULL && m->pindex != pindex) {
767 m = vm_page_splay(pindex, m);
768 if ((object->root = m)->pindex != pindex)
769 m = NULL;
770 }
771 return (m);
772 }
773
774 /*
775 * vm_page_rename:
776 *
777 * Move the given memory entry from its
778 * current object to the specified target object/offset.
779 *
780 * The object must be locked.
781 * This routine may not block.
782 *
783 * Note: swap associated with the page must be invalidated by the move. We
784 * have to do this for several reasons: (1) we aren't freeing the
785 * page, (2) we are dirtying the page, (3) the VM system is probably
786 * moving the page from object A to B, and will then later move
787 * the backing store from A to B and we can't have a conflict.
788 *
789 * Note: we *always* dirty the page. It is necessary both for the
790 * fact that we moved it, and because we may be invalidating
791 * swap. If the page is on the cache, we have to deactivate it
792 * or vm_page_dirty() will panic. Dirty pages are not allowed
793 * on the cache.
794 */
795 void
796 vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
797 {
798
799 vm_page_remove(m);
800 vm_page_insert(m, new_object, new_pindex);
801 vm_page_dirty(m);
802 }
803
804 /*
805 * Convert all of the given object's cached pages that have a
806 * pindex within the given range into free pages. If the value
807 * zero is given for "end", then the range's upper bound is
808 * infinity. If the given object is backed by a vnode and it
809 * transitions from having one or more cached pages to none, the
810 * vnode's hold count is reduced.
811 */
812 void
813 vm_page_cache_free(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
814 {
815 vm_page_t m, m_next;
816 boolean_t empty;
817
818 mtx_lock(&vm_page_queue_free_mtx);
819 if (__predict_false(object->cache == NULL)) {
820 mtx_unlock(&vm_page_queue_free_mtx);
821 return;
822 }
823 m = object->cache = vm_page_splay(start, object->cache);
824 if (m->pindex < start) {
825 if (m->right == NULL)
826 m = NULL;
827 else {
828 m_next = vm_page_splay(start, m->right);
829 m_next->left = m;
830 m->right = NULL;
831 m = object->cache = m_next;
832 }
833 }
834
835 /*
836 * At this point, "m" is either (1) a reference to the page
837 * with the least pindex that is greater than or equal to
838 * "start" or (2) NULL.
839 */
840 for (; m != NULL && (m->pindex < end || end == 0); m = m_next) {
841 /*
842 * Find "m"'s successor and remove "m" from the
843 * object's cache.
844 */
845 if (m->right == NULL) {
846 object->cache = m->left;
847 m_next = NULL;
848 } else {
849 m_next = vm_page_splay(start, m->right);
850 m_next->left = m->left;
851 object->cache = m_next;
852 }
853 /* Convert "m" to a free page. */
854 m->object = NULL;
855 m->valid = 0;
856 /* Clear PG_CACHED and set PG_FREE. */
857 m->flags ^= PG_CACHED | PG_FREE;
858 KASSERT((m->flags & (PG_CACHED | PG_FREE)) == PG_FREE,
859 ("vm_page_cache_free: page %p has inconsistent flags", m));
860 cnt.v_cache_count--;
861 cnt.v_free_count++;
862 }
863 empty = object->cache == NULL;
864 mtx_unlock(&vm_page_queue_free_mtx);
865 if (object->type == OBJT_VNODE && empty)
866 vdrop(object->handle);
867 }
868
869 /*
870 * Returns the cached page that is associated with the given
871 * object and offset. If, however, none exists, returns NULL.
872 *
873 * The free page queue must be locked.
874 */
875 static inline vm_page_t
876 vm_page_cache_lookup(vm_object_t object, vm_pindex_t pindex)
877 {
878 vm_page_t m;
879
880 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
881 if ((m = object->cache) != NULL && m->pindex != pindex) {
882 m = vm_page_splay(pindex, m);
883 if ((object->cache = m)->pindex != pindex)
884 m = NULL;
885 }
886 return (m);
887 }
888
889 /*
890 * Remove the given cached page from its containing object's
891 * collection of cached pages.
892 *
893 * The free page queue must be locked.
894 */
895 void
896 vm_page_cache_remove(vm_page_t m)
897 {
898 vm_object_t object;
899 vm_page_t root;
900
901 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
902 KASSERT((m->flags & PG_CACHED) != 0,
903 ("vm_page_cache_remove: page %p is not cached", m));
904 object = m->object;
905 if (m != object->cache) {
906 root = vm_page_splay(m->pindex, object->cache);
907 KASSERT(root == m,
908 ("vm_page_cache_remove: page %p is not cached in object %p",
909 m, object));
910 }
911 if (m->left == NULL)
912 root = m->right;
913 else if (m->right == NULL)
914 root = m->left;
915 else {
916 root = vm_page_splay(m->pindex, m->left);
917 root->right = m->right;
918 }
919 object->cache = root;
920 m->object = NULL;
921 cnt.v_cache_count--;
922 }
923
924 /*
925 * Transfer all of the cached pages with offset greater than or
926 * equal to 'offidxstart' from the original object's cache to the
927 * new object's cache. However, any cached pages with offset
928 * greater than or equal to the new object's size are kept in the
929 * original object. Initially, the new object's cache must be
930 * empty. Offset 'offidxstart' in the original object must
931 * correspond to offset zero in the new object.
932 *
933 * The new object must be locked.
934 */
935 void
936 vm_page_cache_transfer(vm_object_t orig_object, vm_pindex_t offidxstart,
937 vm_object_t new_object)
938 {
939 vm_page_t m, m_next;
940
941 /*
942 * Insertion into an object's collection of cached pages
943 * requires the object to be locked. In contrast, removal does
944 * not.
945 */
946 VM_OBJECT_LOCK_ASSERT(new_object, MA_OWNED);
947 KASSERT(new_object->cache == NULL,
948 ("vm_page_cache_transfer: object %p has cached pages",
949 new_object));
950 mtx_lock(&vm_page_queue_free_mtx);
951 if ((m = orig_object->cache) != NULL) {
952 /*
953 * Transfer all of the pages with offset greater than or
954 * equal to 'offidxstart' from the original object's
955 * cache to the new object's cache.
956 */
957 m = vm_page_splay(offidxstart, m);
958 if (m->pindex < offidxstart) {
959 orig_object->cache = m;
960 new_object->cache = m->right;
961 m->right = NULL;
962 } else {
963 orig_object->cache = m->left;
964 new_object->cache = m;
965 m->left = NULL;
966 }
967 while ((m = new_object->cache) != NULL) {
968 if ((m->pindex - offidxstart) >= new_object->size) {
969 /*
970 * Return all of the cached pages with
971 * offset greater than or equal to the
972 * new object's size to the original
973 * object's cache.
974 */
975 new_object->cache = m->left;
976 m->left = orig_object->cache;
977 orig_object->cache = m;
978 break;
979 }
980 m_next = vm_page_splay(m->pindex, m->right);
981 /* Update the page's object and offset. */
982 m->object = new_object;
983 m->pindex -= offidxstart;
984 if (m_next == NULL)
985 break;
986 m->right = NULL;
987 m_next->left = m;
988 new_object->cache = m_next;
989 }
990 KASSERT(new_object->cache == NULL ||
991 new_object->type == OBJT_SWAP,
992 ("vm_page_cache_transfer: object %p's type is incompatible"
993 " with cached pages", new_object));
994 }
995 mtx_unlock(&vm_page_queue_free_mtx);
996 }
997
998 /*
999 * vm_page_alloc:
1000 *
1001 * Allocate and return a memory cell associated
1002 * with this VM object/offset pair.
1003 *
1004 * page_req classes:
1005 * VM_ALLOC_NORMAL normal process request
1006 * VM_ALLOC_SYSTEM system *really* needs a page
1007 * VM_ALLOC_INTERRUPT interrupt time request
1008 * VM_ALLOC_ZERO zero page
1009 *
1010 * This routine may not block.
1011 */
1012 vm_page_t
1013 vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
1014 {
1015 struct vnode *vp = NULL;
1016 vm_object_t m_object;
1017 vm_page_t m;
1018 int flags, page_req;
1019
1020 page_req = req & VM_ALLOC_CLASS_MASK;
1021 KASSERT(curthread->td_intr_nesting_level == 0 ||
1022 page_req == VM_ALLOC_INTERRUPT,
1023 ("vm_page_alloc(NORMAL|SYSTEM) in interrupt context"));
1024
1025 if ((req & VM_ALLOC_NOOBJ) == 0) {
1026 KASSERT(object != NULL,
1027 ("vm_page_alloc: NULL object."));
1028 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1029 }
1030
1031 /*
1032 * The pager is allowed to eat deeper into the free page list.
1033 */
1034 if ((curproc == pageproc) && (page_req != VM_ALLOC_INTERRUPT)) {
1035 page_req = VM_ALLOC_SYSTEM;
1036 };
1037
1038 mtx_lock(&vm_page_queue_free_mtx);
1039 if (cnt.v_free_count + cnt.v_cache_count > cnt.v_free_reserved ||
1040 (page_req == VM_ALLOC_SYSTEM &&
1041 cnt.v_free_count + cnt.v_cache_count > cnt.v_interrupt_free_min) ||
1042 (page_req == VM_ALLOC_INTERRUPT &&
1043 cnt.v_free_count + cnt.v_cache_count > 0)) {
1044 /*
1045 * Allocate from the free queue if the number of free pages
1046 * exceeds the minimum for the request class.
1047 */
1048 if (object != NULL &&
1049 (m = vm_page_cache_lookup(object, pindex)) != NULL) {
1050 if ((req & VM_ALLOC_IFNOTCACHED) != 0) {
1051 mtx_unlock(&vm_page_queue_free_mtx);
1052 return (NULL);
1053 }
1054 if (vm_phys_unfree_page(m))
1055 vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, 0);
1056 #if VM_NRESERVLEVEL > 0
1057 else if (!vm_reserv_reactivate_page(m))
1058 #else
1059 else
1060 #endif
1061 panic("vm_page_alloc: cache page %p is missing"
1062 " from the free queue", m);
1063 } else if ((req & VM_ALLOC_IFCACHED) != 0) {
1064 mtx_unlock(&vm_page_queue_free_mtx);
1065 return (NULL);
1066 #if VM_NRESERVLEVEL > 0
1067 } else if (object == NULL || object->type == OBJT_DEVICE ||
1068 (object->flags & OBJ_COLORED) == 0 ||
1069 (m = vm_reserv_alloc_page(object, pindex)) == NULL) {
1070 #else
1071 } else {
1072 #endif
1073 m = vm_phys_alloc_pages(object != NULL ?
1074 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT, 0);
1075 #if VM_NRESERVLEVEL > 0
1076 if (m == NULL && vm_reserv_reclaim_inactive()) {
1077 m = vm_phys_alloc_pages(object != NULL ?
1078 VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT,
1079 0);
1080 }
1081 #endif
1082 }
1083 } else {
1084 /*
1085 * Not allocatable, give up.
1086 */
1087 mtx_unlock(&vm_page_queue_free_mtx);
1088 atomic_add_int(&vm_pageout_deficit, 1);
1089 pagedaemon_wakeup();
1090 return (NULL);
1091 }
1092
1093 /*
1094 * At this point we had better have found a good page.
1095 */
1096
1097 KASSERT(
1098 m != NULL,
1099 ("vm_page_alloc(): missing page on free queue")
1100 );
1101 if ((m->flags & PG_CACHED) != 0) {
1102 KASSERT(m->valid != 0,
1103 ("vm_page_alloc: cached page %p is invalid", m));
1104 if (m->object == object && m->pindex == pindex)
1105 cnt.v_reactivated++;
1106 else
1107 m->valid = 0;
1108 m_object = m->object;
1109 vm_page_cache_remove(m);
1110 if (m_object->type == OBJT_VNODE && m_object->cache == NULL)
1111 vp = m_object->handle;
1112 } else {
1113 KASSERT(VM_PAGE_IS_FREE(m),
1114 ("vm_page_alloc: page %p is not free", m));
1115 KASSERT(m->valid == 0,
1116 ("vm_page_alloc: free page %p is valid", m));
1117 cnt.v_free_count--;
1118 }
1119
1120 /*
1121 * Initialize structure. Only the PG_ZERO flag is inherited.
1122 */
1123 flags = 0;
1124 if (m->flags & PG_ZERO) {
1125 vm_page_zero_count--;
1126 if (req & VM_ALLOC_ZERO)
1127 flags = PG_ZERO;
1128 }
1129 if (object == NULL || object->type == OBJT_PHYS)
1130 flags |= PG_UNMANAGED;
1131 m->flags = flags;
1132 if (req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ))
1133 m->oflags = 0;
1134 else
1135 m->oflags = VPO_BUSY;
1136 if (req & VM_ALLOC_WIRED) {
1137 atomic_add_int(&cnt.v_wire_count, 1);
1138 m->wire_count = 1;
1139 } else
1140 m->wire_count = 0;
1141 m->hold_count = 0;
1142 m->act_count = 0;
1143 m->busy = 0;
1144 KASSERT(m->dirty == 0, ("vm_page_alloc: free/cache page %p was dirty", m));
1145 mtx_unlock(&vm_page_queue_free_mtx);
1146
1147 if ((req & VM_ALLOC_NOOBJ) == 0)
1148 vm_page_insert(m, object, pindex);
1149 else
1150 m->pindex = pindex;
1151
1152 /*
1153 * The following call to vdrop() must come after the above call
1154 * to vm_page_insert() in case both affect the same object and
1155 * vnode. Otherwise, the affected vnode's hold count could
1156 * temporarily become zero.
1157 */
1158 if (vp != NULL)
1159 vdrop(vp);
1160
1161 /*
1162 * Don't wakeup too often - wakeup the pageout daemon when
1163 * we would be nearly out of memory.
1164 */
1165 if (vm_paging_needed())
1166 pagedaemon_wakeup();
1167
1168 return (m);
1169 }
1170
1171 /*
1172 * vm_wait: (also see VM_WAIT macro)
1173 *
1174 * Block until free pages are available for allocation
1175 * - Called in various places before memory allocations.
1176 */
1177 void
1178 vm_wait(void)
1179 {
1180
1181 mtx_lock(&vm_page_queue_free_mtx);
1182 if (curproc == pageproc) {
1183 vm_pageout_pages_needed = 1;
1184 msleep(&vm_pageout_pages_needed, &vm_page_queue_free_mtx,
1185 PDROP | PSWP, "VMWait", 0);
1186 } else {
1187 if (!vm_pages_needed) {
1188 vm_pages_needed = 1;
1189 wakeup(&vm_pages_needed);
1190 }
1191 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PVM,
1192 "vmwait", 0);
1193 }
1194 }
1195
1196 /*
1197 * vm_waitpfault: (also see VM_WAITPFAULT macro)
1198 *
1199 * Block until free pages are available for allocation
1200 * - Called only in vm_fault so that processes page faulting
1201 * can be easily tracked.
1202 * - Sleeps at a lower priority than vm_wait() so that vm_wait()ing
1203 * processes will be able to grab memory first. Do not change
1204 * this balance without careful testing first.
1205 */
1206 void
1207 vm_waitpfault(void)
1208 {
1209
1210 mtx_lock(&vm_page_queue_free_mtx);
1211 if (!vm_pages_needed) {
1212 vm_pages_needed = 1;
1213 wakeup(&vm_pages_needed);
1214 }
1215 msleep(&cnt.v_free_count, &vm_page_queue_free_mtx, PDROP | PUSER,
1216 "pfault", 0);
1217 }
1218
1219 /*
1220 * vm_page_requeue:
1221 *
1222 * If the given page is contained within a page queue, move it to the tail
1223 * of that queue.
1224 *
1225 * The page queues must be locked.
1226 */
1227 void
1228 vm_page_requeue(vm_page_t m)
1229 {
1230 int queue = VM_PAGE_GETQUEUE(m);
1231 struct vpgqueues *vpq;
1232
1233 if (queue != PQ_NONE) {
1234 vpq = &vm_page_queues[queue];
1235 TAILQ_REMOVE(&vpq->pl, m, pageq);
1236 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
1237 }
1238 }
1239
1240 /*
1241 * vm_pageq_remove:
1242 *
1243 * Remove a page from its queue.
1244 *
1245 * The queue containing the given page must be locked.
1246 * This routine may not block.
1247 */
1248 void
1249 vm_pageq_remove(vm_page_t m)
1250 {
1251 int queue = VM_PAGE_GETQUEUE(m);
1252 struct vpgqueues *pq;
1253
1254 if (queue != PQ_NONE) {
1255 VM_PAGE_SETQUEUE2(m, PQ_NONE);
1256 pq = &vm_page_queues[queue];
1257 TAILQ_REMOVE(&pq->pl, m, pageq);
1258 (*pq->cnt)--;
1259 }
1260 }
1261
1262 /*
1263 * vm_page_enqueue:
1264 *
1265 * Add the given page to the specified queue.
1266 *
1267 * The page queues must be locked.
1268 */
1269 static void
1270 vm_page_enqueue(int queue, vm_page_t m)
1271 {
1272 struct vpgqueues *vpq;
1273
1274 vpq = &vm_page_queues[queue];
1275 VM_PAGE_SETQUEUE2(m, queue);
1276 TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
1277 ++*vpq->cnt;
1278 }
1279
1280 /*
1281 * vm_page_activate:
1282 *
1283 * Put the specified page on the active list (if appropriate).
1284 * Ensure that act_count is at least ACT_INIT but do not otherwise
1285 * mess with it.
1286 *
1287 * The page queues must be locked.
1288 * This routine may not block.
1289 */
1290 void
1291 vm_page_activate(vm_page_t m)
1292 {
1293
1294 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1295 if (VM_PAGE_GETKNOWNQUEUE2(m) != PQ_ACTIVE) {
1296 vm_pageq_remove(m);
1297 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
1298 if (m->act_count < ACT_INIT)
1299 m->act_count = ACT_INIT;
1300 vm_page_enqueue(PQ_ACTIVE, m);
1301 }
1302 } else {
1303 if (m->act_count < ACT_INIT)
1304 m->act_count = ACT_INIT;
1305 }
1306 }
1307
1308 /*
1309 * vm_page_free_wakeup:
1310 *
1311 * Helper routine for vm_page_free_toq() and vm_page_cache(). This
1312 * routine is called when a page has been added to the cache or free
1313 * queues.
1314 *
1315 * The page queues must be locked.
1316 * This routine may not block.
1317 */
1318 static inline void
1319 vm_page_free_wakeup(void)
1320 {
1321
1322 mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
1323 /*
1324 * if pageout daemon needs pages, then tell it that there are
1325 * some free.
1326 */
1327 if (vm_pageout_pages_needed &&
1328 cnt.v_cache_count + cnt.v_free_count >= cnt.v_pageout_free_min) {
1329 wakeup(&vm_pageout_pages_needed);
1330 vm_pageout_pages_needed = 0;
1331 }
1332 /*
1333 * wakeup processes that are waiting on memory if we hit a
1334 * high water mark. And wakeup scheduler process if we have
1335 * lots of memory. this process will swapin processes.
1336 */
1337 if (vm_pages_needed && !vm_page_count_min()) {
1338 vm_pages_needed = 0;
1339 wakeup(&cnt.v_free_count);
1340 }
1341 }
1342
1343 /*
1344 * vm_page_free_toq:
1345 *
1346 * Returns the given page to the free list,
1347 * disassociating it with any VM object.
1348 *
1349 * Object and page must be locked prior to entry.
1350 * This routine may not block.
1351 */
1352
1353 void
1354 vm_page_free_toq(vm_page_t m)
1355 {
1356
1357 if (VM_PAGE_GETQUEUE(m) != PQ_NONE)
1358 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1359 KASSERT(!pmap_page_is_mapped(m),
1360 ("vm_page_free_toq: freeing mapped page %p", m));
1361 PCPU_INC(cnt.v_tfree);
1362
1363 if (m->busy || VM_PAGE_IS_FREE(m)) {
1364 printf(
1365 "vm_page_free: pindex(%lu), busy(%d), VPO_BUSY(%d), hold(%d)\n",
1366 (u_long)m->pindex, m->busy, (m->oflags & VPO_BUSY) ? 1 : 0,
1367 m->hold_count);
1368 if (VM_PAGE_IS_FREE(m))
1369 panic("vm_page_free: freeing free page");
1370 else
1371 panic("vm_page_free: freeing busy page");
1372 }
1373
1374 /*
1375 * unqueue, then remove page. Note that we cannot destroy
1376 * the page here because we do not want to call the pager's
1377 * callback routine until after we've put the page on the
1378 * appropriate free queue.
1379 */
1380 vm_pageq_remove(m);
1381 vm_page_remove(m);
1382
1383 /*
1384 * If fictitious remove object association and
1385 * return, otherwise delay object association removal.
1386 */
1387 if ((m->flags & PG_FICTITIOUS) != 0) {
1388 return;
1389 }
1390
1391 m->valid = 0;
1392 vm_page_undirty(m);
1393
1394 if (m->wire_count != 0) {
1395 if (m->wire_count > 1) {
1396 panic("vm_page_free: invalid wire count (%d), pindex: 0x%lx",
1397 m->wire_count, (long)m->pindex);
1398 }
1399 panic("vm_page_free: freeing wired page");
1400 }
1401 if (m->hold_count != 0) {
1402 m->flags &= ~PG_ZERO;
1403 vm_page_enqueue(PQ_HOLD, m);
1404 } else {
1405 mtx_lock(&vm_page_queue_free_mtx);
1406 m->flags |= PG_FREE;
1407 cnt.v_free_count++;
1408 #if VM_NRESERVLEVEL > 0
1409 if (!vm_reserv_free_page(m))
1410 #else
1411 if (TRUE)
1412 #endif
1413 vm_phys_free_pages(m, 0);
1414 if ((m->flags & PG_ZERO) != 0)
1415 ++vm_page_zero_count;
1416 else
1417 vm_page_zero_idle_wakeup();
1418 vm_page_free_wakeup();
1419 mtx_unlock(&vm_page_queue_free_mtx);
1420 }
1421 }
1422
1423 /*
1424 * vm_page_wire:
1425 *
1426 * Mark this page as wired down by yet
1427 * another map, removing it from paging queues
1428 * as necessary.
1429 *
1430 * The page queues must be locked.
1431 * This routine may not block.
1432 */
1433 void
1434 vm_page_wire(vm_page_t m)
1435 {
1436
1437 /*
1438 * Only bump the wire statistics if the page is not already wired,
1439 * and only unqueue the page if it is on some queue (if it is unmanaged
1440 * it is already off the queues).
1441 */
1442 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1443 if (m->flags & PG_FICTITIOUS)
1444 return;
1445 if (m->wire_count == 0) {
1446 if ((m->flags & PG_UNMANAGED) == 0)
1447 vm_pageq_remove(m);
1448 atomic_add_int(&cnt.v_wire_count, 1);
1449 }
1450 m->wire_count++;
1451 KASSERT(m->wire_count != 0, ("vm_page_wire: wire_count overflow m=%p", m));
1452 }
1453
1454 /*
1455 * vm_page_unwire:
1456 *
1457 * Release one wiring of this page, potentially
1458 * enabling it to be paged again.
1459 *
1460 * Many pages placed on the inactive queue should actually go
1461 * into the cache, but it is difficult to figure out which. What
1462 * we do instead, if the inactive target is well met, is to put
1463 * clean pages at the head of the inactive queue instead of the tail.
1464 * This will cause them to be moved to the cache more quickly and
1465 * if not actively re-referenced, freed more quickly. If we just
1466 * stick these pages at the end of the inactive queue, heavy filesystem
1467 * meta-data accesses can cause an unnecessary paging load on memory bound
1468 * processes. This optimization causes one-time-use metadata to be
1469 * reused more quickly.
1470 *
1471 * BUT, if we are in a low-memory situation we have no choice but to
1472 * put clean pages on the cache queue.
1473 *
1474 * A number of routines use vm_page_unwire() to guarantee that the page
1475 * will go into either the inactive or active queues, and will NEVER
1476 * be placed in the cache - for example, just after dirtying a page.
1477 * dirty pages in the cache are not allowed.
1478 *
1479 * The page queues must be locked.
1480 * This routine may not block.
1481 */
1482 void
1483 vm_page_unwire(vm_page_t m, int activate)
1484 {
1485
1486 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1487 if (m->flags & PG_FICTITIOUS)
1488 return;
1489 if (m->wire_count > 0) {
1490 m->wire_count--;
1491 if (m->wire_count == 0) {
1492 atomic_subtract_int(&cnt.v_wire_count, 1);
1493 if (m->flags & PG_UNMANAGED) {
1494 ;
1495 } else if (activate)
1496 vm_page_enqueue(PQ_ACTIVE, m);
1497 else {
1498 vm_page_flag_clear(m, PG_WINATCFLS);
1499 vm_page_enqueue(PQ_INACTIVE, m);
1500 }
1501 }
1502 } else {
1503 panic("vm_page_unwire: invalid wire count: %d", m->wire_count);
1504 }
1505 }
1506
1507
1508 /*
1509 * Move the specified page to the inactive queue. If the page has
1510 * any associated swap, the swap is deallocated.
1511 *
1512 * Normally athead is 0 resulting in LRU operation. athead is set
1513 * to 1 if we want this page to be 'as if it were placed in the cache',
1514 * except without unmapping it from the process address space.
1515 *
1516 * This routine may not block.
1517 */
1518 static inline void
1519 _vm_page_deactivate(vm_page_t m, int athead)
1520 {
1521
1522 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1523
1524 /*
1525 * Ignore if already inactive.
1526 */
1527 if (VM_PAGE_INQUEUE2(m, PQ_INACTIVE))
1528 return;
1529 if (m->wire_count == 0 && (m->flags & PG_UNMANAGED) == 0) {
1530 vm_page_flag_clear(m, PG_WINATCFLS);
1531 vm_pageq_remove(m);
1532 if (athead)
1533 TAILQ_INSERT_HEAD(&vm_page_queues[PQ_INACTIVE].pl, m, pageq);
1534 else
1535 TAILQ_INSERT_TAIL(&vm_page_queues[PQ_INACTIVE].pl, m, pageq);
1536 VM_PAGE_SETQUEUE2(m, PQ_INACTIVE);
1537 cnt.v_inactive_count++;
1538 }
1539 }
1540
1541 void
1542 vm_page_deactivate(vm_page_t m)
1543 {
1544 _vm_page_deactivate(m, 0);
1545 }
1546
1547 /*
1548 * vm_page_try_to_cache:
1549 *
1550 * Returns 0 on failure, 1 on success
1551 */
1552 int
1553 vm_page_try_to_cache(vm_page_t m)
1554 {
1555
1556 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1557 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
1558 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1559 (m->oflags & VPO_BUSY) || (m->flags & PG_UNMANAGED)) {
1560 return (0);
1561 }
1562 pmap_remove_all(m);
1563 if (m->dirty)
1564 return (0);
1565 vm_page_cache(m);
1566 return (1);
1567 }
1568
1569 /*
1570 * vm_page_try_to_free()
1571 *
1572 * Attempt to free the page. If we cannot free it, we do nothing.
1573 * 1 is returned on success, 0 on failure.
1574 */
1575 int
1576 vm_page_try_to_free(vm_page_t m)
1577 {
1578
1579 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1580 if (m->object != NULL)
1581 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
1582 if (m->dirty || m->hold_count || m->busy || m->wire_count ||
1583 (m->oflags & VPO_BUSY) || (m->flags & PG_UNMANAGED)) {
1584 return (0);
1585 }
1586 pmap_remove_all(m);
1587 if (m->dirty)
1588 return (0);
1589 vm_page_free(m);
1590 return (1);
1591 }
1592
1593 /*
1594 * vm_page_cache
1595 *
1596 * Put the specified page onto the page cache queue (if appropriate).
1597 *
1598 * This routine may not block.
1599 */
1600 void
1601 vm_page_cache(vm_page_t m)
1602 {
1603 vm_object_t object;
1604 vm_page_t root;
1605
1606 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1607 object = m->object;
1608 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1609 if ((m->flags & PG_UNMANAGED) || (m->oflags & VPO_BUSY) || m->busy ||
1610 m->hold_count || m->wire_count) {
1611 panic("vm_page_cache: attempting to cache busy page");
1612 }
1613 pmap_remove_all(m);
1614 if (m->dirty != 0)
1615 panic("vm_page_cache: page %p is dirty", m);
1616 if (m->valid == 0 || object->type == OBJT_DEFAULT ||
1617 (object->type == OBJT_SWAP &&
1618 !vm_pager_has_page(object, m->pindex, NULL, NULL))) {
1619 /*
1620 * Hypothesis: A cache-elgible page belonging to a
1621 * default object or swap object but without a backing
1622 * store must be zero filled.
1623 */
1624 vm_page_free(m);
1625 return;
1626 }
1627 KASSERT((m->flags & PG_CACHED) == 0,
1628 ("vm_page_cache: page %p is already cached", m));
1629 cnt.v_tcached++;
1630
1631 /*
1632 * Remove the page from the paging queues.
1633 */
1634 vm_pageq_remove(m);
1635
1636 /*
1637 * Remove the page from the object's collection of resident
1638 * pages.
1639 */
1640 if (m != object->root)
1641 vm_page_splay(m->pindex, object->root);
1642 if (m->left == NULL)
1643 root = m->right;
1644 else {
1645 root = vm_page_splay(m->pindex, m->left);
1646 root->right = m->right;
1647 }
1648 object->root = root;
1649 TAILQ_REMOVE(&object->memq, m, listq);
1650 object->resident_page_count--;
1651 object->generation++;
1652
1653 /*
1654 * Insert the page into the object's collection of cached pages
1655 * and the physical memory allocator's cache/free page queues.
1656 */
1657 vm_page_flag_clear(m, PG_ZERO);
1658 mtx_lock(&vm_page_queue_free_mtx);
1659 m->flags |= PG_CACHED;
1660 cnt.v_cache_count++;
1661 root = object->cache;
1662 if (root == NULL) {
1663 m->left = NULL;
1664 m->right = NULL;
1665 } else {
1666 root = vm_page_splay(m->pindex, root);
1667 if (m->pindex < root->pindex) {
1668 m->left = root->left;
1669 m->right = root;
1670 root->left = NULL;
1671 } else if (__predict_false(m->pindex == root->pindex))
1672 panic("vm_page_cache: offset already cached");
1673 else {
1674 m->right = root->right;
1675 m->left = root;
1676 root->right = NULL;
1677 }
1678 }
1679 object->cache = m;
1680 #if VM_NRESERVLEVEL > 0
1681 if (!vm_reserv_free_page(m)) {
1682 #else
1683 if (TRUE) {
1684 #endif
1685 vm_phys_set_pool(VM_FREEPOOL_CACHE, m, 0);
1686 vm_phys_free_pages(m, 0);
1687 }
1688 vm_page_free_wakeup();
1689 mtx_unlock(&vm_page_queue_free_mtx);
1690
1691 /*
1692 * Increment the vnode's hold count if this is the object's only
1693 * cached page. Decrement the vnode's hold count if this was
1694 * the object's only resident page.
1695 */
1696 if (object->type == OBJT_VNODE) {
1697 if (root == NULL && object->resident_page_count != 0)
1698 vhold(object->handle);
1699 else if (root != NULL && object->resident_page_count == 0)
1700 vdrop(object->handle);
1701 }
1702 }
1703
1704 /*
1705 * vm_page_dontneed
1706 *
1707 * Cache, deactivate, or do nothing as appropriate. This routine
1708 * is typically used by madvise() MADV_DONTNEED.
1709 *
1710 * Generally speaking we want to move the page into the cache so
1711 * it gets reused quickly. However, this can result in a silly syndrome
1712 * due to the page recycling too quickly. Small objects will not be
1713 * fully cached. On the otherhand, if we move the page to the inactive
1714 * queue we wind up with a problem whereby very large objects
1715 * unnecessarily blow away our inactive and cache queues.
1716 *
1717 * The solution is to move the pages based on a fixed weighting. We
1718 * either leave them alone, deactivate them, or move them to the cache,
1719 * where moving them to the cache has the highest weighting.
1720 * By forcing some pages into other queues we eventually force the
1721 * system to balance the queues, potentially recovering other unrelated
1722 * space from active. The idea is to not force this to happen too
1723 * often.
1724 */
1725 void
1726 vm_page_dontneed(vm_page_t m)
1727 {
1728 static int dnweight;
1729 int dnw;
1730 int head;
1731
1732 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1733 dnw = ++dnweight;
1734
1735 /*
1736 * occassionally leave the page alone
1737 */
1738 if ((dnw & 0x01F0) == 0 ||
1739 VM_PAGE_INQUEUE2(m, PQ_INACTIVE)) {
1740 if (m->act_count >= ACT_INIT)
1741 --m->act_count;
1742 return;
1743 }
1744
1745 /*
1746 * Clear any references to the page. Otherwise, the page daemon will
1747 * immediately reactivate the page.
1748 */
1749 vm_page_flag_clear(m, PG_REFERENCED);
1750 pmap_clear_reference(m);
1751
1752 if (m->dirty == 0 && pmap_is_modified(m))
1753 vm_page_dirty(m);
1754
1755 if (m->dirty || (dnw & 0x0070) == 0) {
1756 /*
1757 * Deactivate the page 3 times out of 32.
1758 */
1759 head = 0;
1760 } else {
1761 /*
1762 * Cache the page 28 times out of every 32. Note that
1763 * the page is deactivated instead of cached, but placed
1764 * at the head of the queue instead of the tail.
1765 */
1766 head = 1;
1767 }
1768 _vm_page_deactivate(m, head);
1769 }
1770
1771 /*
1772 * Grab a page, waiting until we are waken up due to the page
1773 * changing state. We keep on waiting, if the page continues
1774 * to be in the object. If the page doesn't exist, first allocate it
1775 * and then conditionally zero it.
1776 *
1777 * This routine may block.
1778 */
1779 vm_page_t
1780 vm_page_grab(vm_object_t object, vm_pindex_t pindex, int allocflags)
1781 {
1782 vm_page_t m;
1783
1784 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1785 retrylookup:
1786 if ((m = vm_page_lookup(object, pindex)) != NULL) {
1787 if (vm_page_sleep_if_busy(m, TRUE, "pgrbwt")) {
1788 if ((allocflags & VM_ALLOC_RETRY) == 0)
1789 return (NULL);
1790 goto retrylookup;
1791 } else {
1792 if ((allocflags & VM_ALLOC_WIRED) != 0) {
1793 vm_page_lock_queues();
1794 vm_page_wire(m);
1795 vm_page_unlock_queues();
1796 }
1797 if ((allocflags & VM_ALLOC_NOBUSY) == 0)
1798 vm_page_busy(m);
1799 return (m);
1800 }
1801 }
1802 m = vm_page_alloc(object, pindex, allocflags & ~VM_ALLOC_RETRY);
1803 if (m == NULL) {
1804 VM_OBJECT_UNLOCK(object);
1805 VM_WAIT;
1806 VM_OBJECT_LOCK(object);
1807 if ((allocflags & VM_ALLOC_RETRY) == 0)
1808 return (NULL);
1809 goto retrylookup;
1810 } else if (m->valid != 0)
1811 return (m);
1812 if (allocflags & VM_ALLOC_ZERO && (m->flags & PG_ZERO) == 0)
1813 pmap_zero_page(m);
1814 return (m);
1815 }
1816
1817 /*
1818 * Mapping function for valid bits or for dirty bits in
1819 * a page. May not block.
1820 *
1821 * Inputs are required to range within a page.
1822 */
1823 int
1824 vm_page_bits(int base, int size)
1825 {
1826 int first_bit;
1827 int last_bit;
1828
1829 KASSERT(
1830 base + size <= PAGE_SIZE,
1831 ("vm_page_bits: illegal base/size %d/%d", base, size)
1832 );
1833
1834 if (size == 0) /* handle degenerate case */
1835 return (0);
1836
1837 first_bit = base >> DEV_BSHIFT;
1838 last_bit = (base + size - 1) >> DEV_BSHIFT;
1839
1840 return ((2 << last_bit) - (1 << first_bit));
1841 }
1842
1843 /*
1844 * vm_page_set_validclean:
1845 *
1846 * Sets portions of a page valid and clean. The arguments are expected
1847 * to be DEV_BSIZE aligned but if they aren't the bitmap is inclusive
1848 * of any partial chunks touched by the range. The invalid portion of
1849 * such chunks will be zero'd.
1850 *
1851 * This routine may not block.
1852 *
1853 * (base + size) must be less then or equal to PAGE_SIZE.
1854 */
1855 void
1856 vm_page_set_validclean(vm_page_t m, int base, int size)
1857 {
1858 int pagebits;
1859 int frag;
1860 int endoff;
1861
1862 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1863 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
1864 if (size == 0) /* handle degenerate case */
1865 return;
1866
1867 /*
1868 * If the base is not DEV_BSIZE aligned and the valid
1869 * bit is clear, we have to zero out a portion of the
1870 * first block.
1871 */
1872 if ((frag = base & ~(DEV_BSIZE - 1)) != base &&
1873 (m->valid & (1 << (base >> DEV_BSHIFT))) == 0)
1874 pmap_zero_page_area(m, frag, base - frag);
1875
1876 /*
1877 * If the ending offset is not DEV_BSIZE aligned and the
1878 * valid bit is clear, we have to zero out a portion of
1879 * the last block.
1880 */
1881 endoff = base + size;
1882 if ((frag = endoff & ~(DEV_BSIZE - 1)) != endoff &&
1883 (m->valid & (1 << (endoff >> DEV_BSHIFT))) == 0)
1884 pmap_zero_page_area(m, endoff,
1885 DEV_BSIZE - (endoff & (DEV_BSIZE - 1)));
1886
1887 /*
1888 * Set valid, clear dirty bits. If validating the entire
1889 * page we can safely clear the pmap modify bit. We also
1890 * use this opportunity to clear the VPO_NOSYNC flag. If a process
1891 * takes a write fault on a MAP_NOSYNC memory area the flag will
1892 * be set again.
1893 *
1894 * We set valid bits inclusive of any overlap, but we can only
1895 * clear dirty bits for DEV_BSIZE chunks that are fully within
1896 * the range.
1897 */
1898 pagebits = vm_page_bits(base, size);
1899 m->valid |= pagebits;
1900 #if 0 /* NOT YET */
1901 if ((frag = base & (DEV_BSIZE - 1)) != 0) {
1902 frag = DEV_BSIZE - frag;
1903 base += frag;
1904 size -= frag;
1905 if (size < 0)
1906 size = 0;
1907 }
1908 pagebits = vm_page_bits(base, size & (DEV_BSIZE - 1));
1909 #endif
1910 m->dirty &= ~pagebits;
1911 if (base == 0 && size == PAGE_SIZE) {
1912 pmap_clear_modify(m);
1913 m->oflags &= ~VPO_NOSYNC;
1914 }
1915 }
1916
1917 void
1918 vm_page_clear_dirty(vm_page_t m, int base, int size)
1919 {
1920
1921 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1922 m->dirty &= ~vm_page_bits(base, size);
1923 }
1924
1925 /*
1926 * vm_page_set_invalid:
1927 *
1928 * Invalidates DEV_BSIZE'd chunks within a page. Both the
1929 * valid and dirty bits for the effected areas are cleared.
1930 *
1931 * May not block.
1932 */
1933 void
1934 vm_page_set_invalid(vm_page_t m, int base, int size)
1935 {
1936 int bits;
1937
1938 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
1939 bits = vm_page_bits(base, size);
1940 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
1941 if (m->valid == VM_PAGE_BITS_ALL && bits != 0)
1942 pmap_remove_all(m);
1943 m->valid &= ~bits;
1944 m->dirty &= ~bits;
1945 m->object->generation++;
1946 }
1947
1948 /*
1949 * vm_page_zero_invalid()
1950 *
1951 * The kernel assumes that the invalid portions of a page contain
1952 * garbage, but such pages can be mapped into memory by user code.
1953 * When this occurs, we must zero out the non-valid portions of the
1954 * page so user code sees what it expects.
1955 *
1956 * Pages are most often semi-valid when the end of a file is mapped
1957 * into memory and the file's size is not page aligned.
1958 */
1959 void
1960 vm_page_zero_invalid(vm_page_t m, boolean_t setvalid)
1961 {
1962 int b;
1963 int i;
1964
1965 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
1966 /*
1967 * Scan the valid bits looking for invalid sections that
1968 * must be zerod. Invalid sub-DEV_BSIZE'd areas ( where the
1969 * valid bit may be set ) have already been zerod by
1970 * vm_page_set_validclean().
1971 */
1972 for (b = i = 0; i <= PAGE_SIZE / DEV_BSIZE; ++i) {
1973 if (i == (PAGE_SIZE / DEV_BSIZE) ||
1974 (m->valid & (1 << i))
1975 ) {
1976 if (i > b) {
1977 pmap_zero_page_area(m,
1978 b << DEV_BSHIFT, (i - b) << DEV_BSHIFT);
1979 }
1980 b = i + 1;
1981 }
1982 }
1983
1984 /*
1985 * setvalid is TRUE when we can safely set the zero'd areas
1986 * as being valid. We can do this if there are no cache consistancy
1987 * issues. e.g. it is ok to do with UFS, but not ok to do with NFS.
1988 */
1989 if (setvalid)
1990 m->valid = VM_PAGE_BITS_ALL;
1991 }
1992
1993 /*
1994 * vm_page_is_valid:
1995 *
1996 * Is (partial) page valid? Note that the case where size == 0
1997 * will return FALSE in the degenerate case where the page is
1998 * entirely invalid, and TRUE otherwise.
1999 *
2000 * May not block.
2001 */
2002 int
2003 vm_page_is_valid(vm_page_t m, int base, int size)
2004 {
2005 int bits = vm_page_bits(base, size);
2006
2007 VM_OBJECT_LOCK_ASSERT(m->object, MA_OWNED);
2008 if (m->valid && ((m->valid & bits) == bits))
2009 return 1;
2010 else
2011 return 0;
2012 }
2013
2014 /*
2015 * update dirty bits from pmap/mmu. May not block.
2016 */
2017 void
2018 vm_page_test_dirty(vm_page_t m)
2019 {
2020 if ((m->dirty != VM_PAGE_BITS_ALL) && pmap_is_modified(m)) {
2021 vm_page_dirty(m);
2022 }
2023 }
2024
2025 int so_zerocp_fullpage = 0;
2026
2027 /*
2028 * Replace the given page with a copy. The copied page assumes
2029 * the portion of the given page's "wire_count" that is not the
2030 * responsibility of this copy-on-write mechanism.
2031 *
2032 * The object containing the given page must have a non-zero
2033 * paging-in-progress count and be locked.
2034 */
2035 void
2036 vm_page_cowfault(vm_page_t m)
2037 {
2038 vm_page_t mnew;
2039 vm_object_t object;
2040 vm_pindex_t pindex;
2041
2042 object = m->object;
2043 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
2044 KASSERT(object->paging_in_progress != 0,
2045 ("vm_page_cowfault: object %p's paging-in-progress count is zero.",
2046 object));
2047 pindex = m->pindex;
2048
2049 retry_alloc:
2050 pmap_remove_all(m);
2051 vm_page_remove(m);
2052 mnew = vm_page_alloc(object, pindex, VM_ALLOC_NORMAL | VM_ALLOC_NOBUSY);
2053 if (mnew == NULL) {
2054 vm_page_insert(m, object, pindex);
2055 vm_page_unlock_queues();
2056 VM_OBJECT_UNLOCK(object);
2057 VM_WAIT;
2058 VM_OBJECT_LOCK(object);
2059 if (m == vm_page_lookup(object, pindex)) {
2060 vm_page_lock_queues();
2061 goto retry_alloc;
2062 } else {
2063 /*
2064 * Page disappeared during the wait.
2065 */
2066 vm_page_lock_queues();
2067 return;
2068 }
2069 }
2070
2071 if (m->cow == 0) {
2072 /*
2073 * check to see if we raced with an xmit complete when
2074 * waiting to allocate a page. If so, put things back
2075 * the way they were
2076 */
2077 vm_page_free(mnew);
2078 vm_page_insert(m, object, pindex);
2079 } else { /* clear COW & copy page */
2080 if (!so_zerocp_fullpage)
2081 pmap_copy_page(m, mnew);
2082 mnew->valid = VM_PAGE_BITS_ALL;
2083 vm_page_dirty(mnew);
2084 mnew->wire_count = m->wire_count - m->cow;
2085 m->wire_count = m->cow;
2086 }
2087 }
2088
2089 void
2090 vm_page_cowclear(vm_page_t m)
2091 {
2092
2093 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2094 if (m->cow) {
2095 m->cow--;
2096 /*
2097 * let vm_fault add back write permission lazily
2098 */
2099 }
2100 /*
2101 * sf_buf_free() will free the page, so we needn't do it here
2102 */
2103 }
2104
2105 int
2106 vm_page_cowsetup(vm_page_t m)
2107 {
2108
2109 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
2110 if (m->cow == USHRT_MAX - 1)
2111 return (EBUSY);
2112 m->cow++;
2113 pmap_remove_write(m);
2114 return (0);
2115 }
2116
2117 #include "opt_ddb.h"
2118 #ifdef DDB
2119 #include <sys/kernel.h>
2120
2121 #include <ddb/ddb.h>
2122
2123 DB_SHOW_COMMAND(page, vm_page_print_page_info)
2124 {
2125 db_printf("cnt.v_free_count: %d\n", cnt.v_free_count);
2126 db_printf("cnt.v_cache_count: %d\n", cnt.v_cache_count);
2127 db_printf("cnt.v_inactive_count: %d\n", cnt.v_inactive_count);
2128 db_printf("cnt.v_active_count: %d\n", cnt.v_active_count);
2129 db_printf("cnt.v_wire_count: %d\n", cnt.v_wire_count);
2130 db_printf("cnt.v_free_reserved: %d\n", cnt.v_free_reserved);
2131 db_printf("cnt.v_free_min: %d\n", cnt.v_free_min);
2132 db_printf("cnt.v_free_target: %d\n", cnt.v_free_target);
2133 db_printf("cnt.v_cache_min: %d\n", cnt.v_cache_min);
2134 db_printf("cnt.v_inactive_target: %d\n", cnt.v_inactive_target);
2135 }
2136
2137 DB_SHOW_COMMAND(pageq, vm_page_print_pageq_info)
2138 {
2139
2140 db_printf("PQ_FREE:");
2141 db_printf(" %d", cnt.v_free_count);
2142 db_printf("\n");
2143
2144 db_printf("PQ_CACHE:");
2145 db_printf(" %d", cnt.v_cache_count);
2146 db_printf("\n");
2147
2148 db_printf("PQ_ACTIVE: %d, PQ_INACTIVE: %d\n",
2149 *vm_page_queues[PQ_ACTIVE].cnt,
2150 *vm_page_queues[PQ_INACTIVE].cnt);
2151 }
2152 #endif /* DDB */
Cache object: 7d1a4107f5ef3608edf7acfda5dc4455
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