1/*
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94
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 * $FreeBSD: head/sys/vm/vm_object.c 92511 2002-03-17 18:37:37Z alc $
65 */
66
67/*
68 * Virtual memory object module.
69 */
70
71#include <sys/param.h>
72#include <sys/systm.h>
73#include <sys/lock.h>
74#include <sys/mman.h>
75#include <sys/mount.h>
76#include <sys/kernel.h>
77#include <sys/sysctl.h>
78#include <sys/mutex.h>
79#include <sys/proc.h> /* for curproc, pageproc */
80#include <sys/socket.h>
81#include <sys/vnode.h>
82#include <sys/vmmeter.h>
83#include <sys/sx.h>
84
85#include <vm/vm.h>
86#include <vm/vm_param.h>
87#include <vm/pmap.h>
88#include <vm/vm_map.h>
89#include <vm/vm_object.h>
90#include <vm/vm_page.h>
91#include <vm/vm_pageout.h>
92#include <vm/vm_pager.h>
93#include <vm/vm_zone.h>
94#include <vm/swap_pager.h>
95#include <vm/vm_kern.h>
96#include <vm/vm_extern.h>
97
98#define EASY_SCAN_FACTOR 8
99
100#define MSYNC_FLUSH_HARDSEQ 0x01
101#define MSYNC_FLUSH_SOFTSEQ 0x02
102
103/*
104 * msync / VM object flushing optimizations
105 */
106static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ;
107SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags,
108 CTLFLAG_RW, &msync_flush_flags, 0, "");
109
110static void vm_object_qcollapse(vm_object_t object);
111static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags);
112
113/*
114 * Virtual memory objects maintain the actual data
115 * associated with allocated virtual memory. A given
116 * page of memory exists within exactly one object.
117 *
118 * An object is only deallocated when all "references"
119 * are given up. Only one "reference" to a given
120 * region of an object should be writeable.
121 *
122 * Associated with each object is a list of all resident
123 * memory pages belonging to that object; this list is
124 * maintained by the "vm_page" module, and locked by the object's
125 * lock.
126 *
127 * Each object also records a "pager" routine which is
128 * used to retrieve (and store) pages to the proper backing
129 * storage. In addition, objects may be backed by other
130 * objects from which they were virtual-copied.
131 *
132 * The only items within the object structure which are
133 * modified after time of creation are:
134 * reference count locked by object's lock
135 * pager routine locked by object's lock
136 *
137 */
138
139struct object_q vm_object_list;
140static struct mtx vm_object_list_mtx; /* lock for object list and count */
141vm_object_t kernel_object;
142vm_object_t kmem_object;
143static struct vm_object kernel_object_store;
144static struct vm_object kmem_object_store;
145extern int vm_pageout_page_count;
146
147static long object_collapses;
148static long object_bypasses;
149static int next_index;
150static vm_zone_t obj_zone;
151static struct vm_zone obj_zone_store;
152static int object_hash_rand;
153#define VM_OBJECTS_INIT 256
154static struct vm_object vm_objects_init[VM_OBJECTS_INIT];
155
156void
157_vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object)
158{
159 int incr;
160
161 GIANT_REQUIRED;
162
163 TAILQ_INIT(&object->memq);
164 TAILQ_INIT(&object->shadow_head);
165
166 object->type = type;
167 object->size = size;
168 object->ref_count = 1;
169 object->flags = 0;
170 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
171 vm_object_set_flag(object, OBJ_ONEMAPPING);
172 object->paging_in_progress = 0;
173 object->resident_page_count = 0;
174 object->shadow_count = 0;
175 object->pg_color = next_index;
176 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
177 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
178 else
179 incr = size;
180 next_index = (next_index + incr) & PQ_L2_MASK;
181 object->handle = NULL;
182 object->backing_object = NULL;
183 object->backing_object_offset = (vm_ooffset_t) 0;
184 /*
185 * Try to generate a number that will spread objects out in the
186 * hash table. We 'wipe' new objects across the hash in 128 page
187 * increments plus 1 more to offset it a little more by the time
188 * it wraps around.
189 */
190 object->hash_rand = object_hash_rand - 129;
191
192 object->generation++;
193
194 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
195
196 object_hash_rand = object->hash_rand;
197}
198
199/*
200 * vm_object_init:
201 *
202 * Initialize the VM objects module.
203 */
204void
205vm_object_init(void)
206{
207 GIANT_REQUIRED;
208
209 TAILQ_INIT(&vm_object_list);
210 mtx_init(&vm_object_list_mtx, "vm object_list", MTX_DEF);
211
212 kernel_object = &kernel_object_store;
213 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
214 kernel_object);
215
216 kmem_object = &kmem_object_store;
217 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
218 kmem_object);
219
220 obj_zone = &obj_zone_store;
221 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object),
222 vm_objects_init, VM_OBJECTS_INIT);
223}
224
225void
226vm_object_init2(void)
227{
228 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1);
229}
230
231void
232vm_object_set_flag(vm_object_t object, u_short bits)
233{
234 GIANT_REQUIRED;
235 object->flags |= bits;
236}
237
238void
239vm_object_clear_flag(vm_object_t object, u_short bits)
240{
241 GIANT_REQUIRED;
242 object->flags &= ~bits;
243}
244
245void
246vm_object_pip_add(vm_object_t object, short i)
247{
248 GIANT_REQUIRED;
249 object->paging_in_progress += i;
250}
251
252void
253vm_object_pip_subtract(vm_object_t object, short i)
254{
255 GIANT_REQUIRED;
256 object->paging_in_progress -= i;
257}
258
259void
260vm_object_pip_wakeup(vm_object_t object)
261{
262 GIANT_REQUIRED;
263 object->paging_in_progress--;
264 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
265 vm_object_clear_flag(object, OBJ_PIPWNT);
266 wakeup(object);
267 }
268}
269
270void
271vm_object_pip_wakeupn(vm_object_t object, short i)
272{
273 GIANT_REQUIRED;
274 if (i)
275 object->paging_in_progress -= i;
276 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
277 vm_object_clear_flag(object, OBJ_PIPWNT);
278 wakeup(object);
279 }
280}
281
282void
283vm_object_pip_sleep(vm_object_t object, char *waitid)
284{
285 GIANT_REQUIRED;
286 if (object->paging_in_progress) {
287 int s = splvm();
288 if (object->paging_in_progress) {
289 vm_object_set_flag(object, OBJ_PIPWNT);
290 tsleep(object, PVM, waitid, 0);
291 }
292 splx(s);
293 }
294}
295
296void
297vm_object_pip_wait(vm_object_t object, char *waitid)
298{
299 GIANT_REQUIRED;
300 while (object->paging_in_progress)
301 vm_object_pip_sleep(object, waitid);
302}
303
304/*
305 * vm_object_allocate:
306 *
307 * Returns a new object with the given size.
308 */
309vm_object_t
310vm_object_allocate(objtype_t type, vm_size_t size)
311{
312 vm_object_t result;
313
314 GIANT_REQUIRED;
315
316 result = (vm_object_t) zalloc(obj_zone);
317 _vm_object_allocate(type, size, result);
318
319 return (result);
320}
321
322
323/*
324 * vm_object_reference:
325 *
326 * Gets another reference to the given object.
327 */
328void
329vm_object_reference(vm_object_t object)
330{
331 GIANT_REQUIRED;
332
333 if (object == NULL)
334 return;
335
336#if 0
337 /* object can be re-referenced during final cleaning */
338 KASSERT(!(object->flags & OBJ_DEAD),
339 ("vm_object_reference: attempting to reference dead obj"));
340#endif
341
342 object->ref_count++;
343 if (object->type == OBJT_VNODE) {
344 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) {
345 printf("vm_object_reference: delay in getting object\n");
346 }
347 }
348}
349
350/*
351 * handle deallocating a object of type OBJT_VNODE
352 */
353void
354vm_object_vndeallocate(vm_object_t object)
355{
356 struct vnode *vp = (struct vnode *) object->handle;
357
358 GIANT_REQUIRED;
359 KASSERT(object->type == OBJT_VNODE,
360 ("vm_object_vndeallocate: not a vnode object"));
361 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
362#ifdef INVARIANTS
363 if (object->ref_count == 0) {
364 vprint("vm_object_vndeallocate", vp);
365 panic("vm_object_vndeallocate: bad object reference count");
366 }
367#endif
368
369 object->ref_count--;
370 if (object->ref_count == 0) {
371 vp->v_flag &= ~VTEXT;
372 vm_object_clear_flag(object, OBJ_OPT);
373 }
374 /*
375 * vrele may need a vop lock
376 */
377 vrele(vp);
378}
379
380/*
381 * vm_object_deallocate:
382 *
383 * Release a reference to the specified object,
384 * gained either through a vm_object_allocate
385 * or a vm_object_reference call. When all references
386 * are gone, storage associated with this object
387 * may be relinquished.
388 *
389 * No object may be locked.
390 */
391void
392vm_object_deallocate(vm_object_t object)
393{
394 vm_object_t temp;
395
396 GIANT_REQUIRED;
397
398 while (object != NULL) {
399
400 if (object->type == OBJT_VNODE) {
401 vm_object_vndeallocate(object);
402 return;
403 }
404
405 KASSERT(object->ref_count != 0,
406 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
407
408 /*
409 * If the reference count goes to 0 we start calling
410 * vm_object_terminate() on the object chain.
411 * A ref count of 1 may be a special case depending on the
412 * shadow count being 0 or 1.
413 */
414 object->ref_count--;
415 if (object->ref_count > 1) {
416 return;
417 } else if (object->ref_count == 1) {
418 if (object->shadow_count == 0) {
419 vm_object_set_flag(object, OBJ_ONEMAPPING);
420 } else if ((object->shadow_count == 1) &&
421 (object->handle == NULL) &&
422 (object->type == OBJT_DEFAULT ||
423 object->type == OBJT_SWAP)) {
424 vm_object_t robject;
425
426 robject = TAILQ_FIRST(&object->shadow_head);
427 KASSERT(robject != NULL,
428 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
429 object->ref_count,
430 object->shadow_count));
431 if ((robject->handle == NULL) &&
432 (robject->type == OBJT_DEFAULT ||
433 robject->type == OBJT_SWAP)) {
434
435 robject->ref_count++;
436
437 while (
438 robject->paging_in_progress ||
439 object->paging_in_progress
440 ) {
441 vm_object_pip_sleep(robject, "objde1");
442 vm_object_pip_sleep(object, "objde2");
443 }
444
445 if (robject->ref_count == 1) {
446 robject->ref_count--;
447 object = robject;
448 goto doterm;
449 }
450
451 object = robject;
452 vm_object_collapse(object);
453 continue;
454 }
455 }
456
457 return;
458
459 }
460
461doterm:
462
463 temp = object->backing_object;
464 if (temp) {
465 TAILQ_REMOVE(&temp->shadow_head, object, shadow_list);
466 temp->shadow_count--;
467 if (temp->ref_count == 0)
468 vm_object_clear_flag(temp, OBJ_OPT);
469 temp->generation++;
470 object->backing_object = NULL;
471 }
472 /*
473 * Don't double-terminate, we could be in a termination
474 * recursion due to the terminate having to sync data
475 * to disk.
476 */
477 if ((object->flags & OBJ_DEAD) == 0)
478 vm_object_terminate(object);
479 object = temp;
480 }
481}
482
483/*
484 * vm_object_terminate actually destroys the specified object, freeing
485 * up all previously used resources.
486 *
487 * The object must be locked.
488 * This routine may block.
489 */
490void
491vm_object_terminate(vm_object_t object)
492{
493 vm_page_t p;
494 int s;
495
496 GIANT_REQUIRED;
497
498 /*
499 * Make sure no one uses us.
500 */
501 vm_object_set_flag(object, OBJ_DEAD);
502
503 /*
504 * wait for the pageout daemon to be done with the object
505 */
506 vm_object_pip_wait(object, "objtrm");
507
508 KASSERT(!object->paging_in_progress,
509 ("vm_object_terminate: pageout in progress"));
510
511 /*
512 * Clean and free the pages, as appropriate. All references to the
513 * object are gone, so we don't need to lock it.
514 */
515 if (object->type == OBJT_VNODE) {
516 struct vnode *vp;
517
518 /*
519 * Freeze optimized copies.
520 */
521 vm_freeze_copyopts(object, 0, object->size);
522
523 /*
524 * Clean pages and flush buffers.
525 */
526 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
527
528 vp = (struct vnode *) object->handle;
529 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
530 }
531
532 KASSERT(object->ref_count == 0,
533 ("vm_object_terminate: object with references, ref_count=%d",
534 object->ref_count));
535
536 /*
537 * Now free any remaining pages. For internal objects, this also
538 * removes them from paging queues. Don't free wired pages, just
539 * remove them from the object.
540 */
541 s = splvm();
542 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
543 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
544 ("vm_object_terminate: freeing busy page %p "
545 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
546 if (p->wire_count == 0) {
547 vm_page_busy(p);
548 vm_page_free(p);
549 cnt.v_pfree++;
550 } else {
551 vm_page_busy(p);
552 vm_page_remove(p);
553 }
554 }
555 splx(s);
556
557 /*
558 * Let the pager know object is dead.
559 */
560 vm_pager_deallocate(object);
561
562 /*
563 * Remove the object from the global object list.
564 */
565 mtx_lock(&vm_object_list_mtx);
566 TAILQ_REMOVE(&vm_object_list, object, object_list);
567 mtx_unlock(&vm_object_list_mtx);
568
569 wakeup(object);
570
571 /*
572 * Free the space for the object.
573 */
574 zfree(obj_zone, object);
575}
576
577/*
578 * vm_object_page_clean
579 *
580 * Clean all dirty pages in the specified range of object. Leaves page
581 * on whatever queue it is currently on. If NOSYNC is set then do not
582 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
583 * leaving the object dirty.
584 *
585 * Odd semantics: if start == end, we clean everything.
586 *
587 * The object must be locked.
588 */
589void
590vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
591{
592 vm_page_t p, np;
593 vm_offset_t tstart, tend;
594 vm_pindex_t pi;
595 struct vnode *vp;
596 int clearobjflags;
597 int pagerflags;
598 int curgeneration;
599
600 GIANT_REQUIRED;
601
602 if (object->type != OBJT_VNODE ||
603 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
604 return;
605
606 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : 0;
607 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
608
609 vp = object->handle;
610
611 vm_object_set_flag(object, OBJ_CLEANING);
612
613 tstart = start;
614 if (end == 0) {
615 tend = object->size;
616 } else {
617 tend = end;
618 }
619
620 /*
621 * If the caller is smart and only msync()s a range he knows is
622 * dirty, we may be able to avoid an object scan. This results in
623 * a phenominal improvement in performance. We cannot do this
624 * as a matter of course because the object may be huge - e.g.
625 * the size might be in the gigabytes or terrabytes.
626 */
627 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
628 vm_offset_t tscan;
629 int scanlimit;
630 int scanreset;
631
632 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
633 if (scanreset < 16)
634 scanreset = 16;
635
636 scanlimit = scanreset;
637 tscan = tstart;
638 while (tscan < tend) {
639 curgeneration = object->generation;
640 p = vm_page_lookup(object, tscan);
641 if (p == NULL || p->valid == 0 ||
642 (p->queue - p->pc) == PQ_CACHE) {
643 if (--scanlimit == 0)
644 break;
645 ++tscan;
646 continue;
647 }
648 vm_page_test_dirty(p);
649 if ((p->dirty & p->valid) == 0) {
650 if (--scanlimit == 0)
651 break;
652 ++tscan;
653 continue;
654 }
655 /*
656 * If we have been asked to skip nosync pages and
657 * this is a nosync page, we can't continue.
658 */
659 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
660 if (--scanlimit == 0)
661 break;
662 ++tscan;
663 continue;
664 }
665 scanlimit = scanreset;
666
667 /*
668 * This returns 0 if it was unable to busy the first
669 * page (i.e. had to sleep).
670 */
671 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
672 }
673
674 /*
675 * If everything was dirty and we flushed it successfully,
676 * and the requested range is not the entire object, we
677 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
678 * return immediately.
679 */
680 if (tscan >= tend && (tstart || tend < object->size)) {
681 vm_object_clear_flag(object, OBJ_CLEANING);
682 return;
683 }
684 }
685
686 /*
687 * Generally set CLEANCHK interlock and make the page read-only so
688 * we can then clear the object flags.
689 *
690 * However, if this is a nosync mmap then the object is likely to
691 * stay dirty so do not mess with the page and do not clear the
692 * object flags.
693 */
694 clearobjflags = 1;
695
696 TAILQ_FOREACH(p, &object->memq, listq) {
697 vm_page_flag_set(p, PG_CLEANCHK);
698 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
699 clearobjflags = 0;
700 else
701 vm_page_protect(p, VM_PROT_READ);
702 }
703
704 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
705 struct vnode *vp;
706
707 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
708 if (object->type == OBJT_VNODE &&
709 (vp = (struct vnode *)object->handle) != NULL) {
710 if (vp->v_flag & VOBJDIRTY) {
711 mtx_lock(&vp->v_interlock);
712 vp->v_flag &= ~VOBJDIRTY;
713 mtx_unlock(&vp->v_interlock);
714 }
715 }
716 }
717
718rescan:
719 curgeneration = object->generation;
720
721 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
722 int n;
723
724 np = TAILQ_NEXT(p, listq);
725
726again:
727 pi = p->pindex;
728 if (((p->flags & PG_CLEANCHK) == 0) ||
729 (pi < tstart) || (pi >= tend) ||
730 (p->valid == 0) ||
731 ((p->queue - p->pc) == PQ_CACHE)) {
732 vm_page_flag_clear(p, PG_CLEANCHK);
733 continue;
734 }
735
736 vm_page_test_dirty(p);
737 if ((p->dirty & p->valid) == 0) {
738 vm_page_flag_clear(p, PG_CLEANCHK);
739 continue;
740 }
741
742 /*
743 * If we have been asked to skip nosync pages and this is a
744 * nosync page, skip it. Note that the object flags were
745 * not cleared in this case so we do not have to set them.
746 */
747 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
748 vm_page_flag_clear(p, PG_CLEANCHK);
749 continue;
750 }
751
752 n = vm_object_page_collect_flush(object, p,
753 curgeneration, pagerflags);
754 if (n == 0)
755 goto rescan;
756
757 if (object->generation != curgeneration)
758 goto rescan;
759
760 /*
761 * Try to optimize the next page. If we can't we pick up
762 * our (random) scan where we left off.
763 */
764 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
765 if ((p = vm_page_lookup(object, pi + n)) != NULL)
766 goto again;
767 }
768 }
769
770#if 0
771 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
772#endif
773
774 vm_object_clear_flag(object, OBJ_CLEANING);
775 return;
776}
777
778static int
779vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
780{
781 int runlen;
782 int s;
783 int maxf;
784 int chkb;
785 int maxb;
786 int i;
787 vm_pindex_t pi;
788 vm_page_t maf[vm_pageout_page_count];
789 vm_page_t mab[vm_pageout_page_count];
790 vm_page_t ma[vm_pageout_page_count];
791
792 s = splvm();
793 pi = p->pindex;
794 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
795 if (object->generation != curgeneration) {
796 splx(s);
797 return(0);
798 }
799 }
800
801 maxf = 0;
802 for(i = 1; i < vm_pageout_page_count; i++) {
803 vm_page_t tp;
804
805 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
806 if ((tp->flags & PG_BUSY) ||
807 (tp->flags & PG_CLEANCHK) == 0 ||
808 (tp->busy != 0))
809 break;
810 if((tp->queue - tp->pc) == PQ_CACHE) {
811 vm_page_flag_clear(tp, PG_CLEANCHK);
812 break;
813 }
814 vm_page_test_dirty(tp);
815 if ((tp->dirty & tp->valid) == 0) {
816 vm_page_flag_clear(tp, PG_CLEANCHK);
817 break;
818 }
819 maf[ i - 1 ] = tp;
820 maxf++;
821 continue;
822 }
823 break;
824 }
825
826 maxb = 0;
827 chkb = vm_pageout_page_count - maxf;
828 if (chkb) {
829 for(i = 1; i < chkb;i++) {
830 vm_page_t tp;
831
832 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
833 if ((tp->flags & PG_BUSY) ||
834 (tp->flags & PG_CLEANCHK) == 0 ||
835 (tp->busy != 0))
836 break;
837 if ((tp->queue - tp->pc) == PQ_CACHE) {
838 vm_page_flag_clear(tp, PG_CLEANCHK);
839 break;
840 }
841 vm_page_test_dirty(tp);
842 if ((tp->dirty & tp->valid) == 0) {
843 vm_page_flag_clear(tp, PG_CLEANCHK);
844 break;
845 }
846 mab[ i - 1 ] = tp;
847 maxb++;
848 continue;
849 }
850 break;
851 }
852 }
853
854 for(i = 0; i < maxb; i++) {
855 int index = (maxb - i) - 1;
856 ma[index] = mab[i];
857 vm_page_flag_clear(ma[index], PG_CLEANCHK);
858 }
859 vm_page_flag_clear(p, PG_CLEANCHK);
860 ma[maxb] = p;
861 for(i = 0; i < maxf; i++) {
862 int index = (maxb + i) + 1;
863 ma[index] = maf[i];
864 vm_page_flag_clear(ma[index], PG_CLEANCHK);
865 }
866 runlen = maxb + maxf + 1;
867
868 splx(s);
869 vm_pageout_flush(ma, runlen, pagerflags);
870 for (i = 0; i < runlen; i++) {
871 if (ma[i]->valid & ma[i]->dirty) {
872 vm_page_protect(ma[i], VM_PROT_READ);
873 vm_page_flag_set(ma[i], PG_CLEANCHK);
874
875 /*
876 * maxf will end up being the actual number of pages
877 * we wrote out contiguously, non-inclusive of the
878 * first page. We do not count look-behind pages.
879 */
880 if (i >= maxb + 1 && (maxf > i - maxb - 1))
881 maxf = i - maxb - 1;
882 }
883 }
884 return(maxf + 1);
885}
886
887/*
888 * Same as vm_object_pmap_copy, except range checking really
889 * works, and is meant for small sections of an object.
890 *
891 * This code protects resident pages by making them read-only
892 * and is typically called on a fork or split when a page
893 * is converted to copy-on-write.
894 *
895 * NOTE: If the page is already at VM_PROT_NONE, calling
896 * vm_page_protect will have no effect.
897 */
898void
899vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
900{
901 vm_pindex_t idx;
902 vm_page_t p;
903
904 GIANT_REQUIRED;
905
906 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
907 return;
908
909 for (idx = start; idx < end; idx++) {
910 p = vm_page_lookup(object, idx);
911 if (p == NULL)
912 continue;
913 vm_page_protect(p, VM_PROT_READ);
914 }
915}
916
917/*
918 * vm_object_pmap_remove:
919 *
920 * Removes all physical pages in the specified
921 * object range from all physical maps.
922 *
923 * The object must *not* be locked.
924 */
925void
926vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
927{
928 vm_page_t p;
929
930 GIANT_REQUIRED;
931 if (object == NULL)
932 return;
933 TAILQ_FOREACH(p, &object->memq, listq) {
934 if (p->pindex >= start && p->pindex < end)
935 vm_page_protect(p, VM_PROT_NONE);
936 }
937 if ((start == 0) && (object->size == end))
938 vm_object_clear_flag(object, OBJ_WRITEABLE);
939}
940
941/*
942 * vm_object_madvise:
943 *
944 * Implements the madvise function at the object/page level.
945 *
946 * MADV_WILLNEED (any object)
947 *
948 * Activate the specified pages if they are resident.
949 *
950 * MADV_DONTNEED (any object)
951 *
952 * Deactivate the specified pages if they are resident.
953 *
954 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
955 * OBJ_ONEMAPPING only)
956 *
957 * Deactivate and clean the specified pages if they are
958 * resident. This permits the process to reuse the pages
959 * without faulting or the kernel to reclaim the pages
960 * without I/O.
961 */
962void
963vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
964{
965 vm_pindex_t end, tpindex;
966 vm_object_t tobject;
967 vm_page_t m;
968
969 GIANT_REQUIRED;
970 if (object == NULL)
971 return;
972
973 end = pindex + count;
974
975 /*
976 * Locate and adjust resident pages
977 */
978 for (; pindex < end; pindex += 1) {
979relookup:
980 tobject = object;
981 tpindex = pindex;
982shadowlookup:
983 /*
984 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
985 * and those pages must be OBJ_ONEMAPPING.
986 */
987 if (advise == MADV_FREE) {
988 if ((tobject->type != OBJT_DEFAULT &&
989 tobject->type != OBJT_SWAP) ||
990 (tobject->flags & OBJ_ONEMAPPING) == 0) {
991 continue;
992 }
993 }
994
995 m = vm_page_lookup(tobject, tpindex);
996
997 if (m == NULL) {
998 /*
999 * There may be swap even if there is no backing page
1000 */
1001 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1002 swap_pager_freespace(tobject, tpindex, 1);
1003
1004 /*
1005 * next object
1006 */
1007 tobject = tobject->backing_object;
1008 if (tobject == NULL)
1009 continue;
1010 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1011 goto shadowlookup;
1012 }
1013
1014 /*
1015 * If the page is busy or not in a normal active state,
1016 * we skip it. If the page is not managed there are no
1017 * page queues to mess with. Things can break if we mess
1018 * with pages in any of the below states.
1019 */
1020 if (
1021 m->hold_count ||
1022 m->wire_count ||
1023 (m->flags & PG_UNMANAGED) ||
1024 m->valid != VM_PAGE_BITS_ALL
1025 ) {
1026 continue;
1027 }
1028
1029 if (vm_page_sleep_busy(m, TRUE, "madvpo"))
1030 goto relookup;
1031
1032 if (advise == MADV_WILLNEED) {
1033 vm_page_activate(m);
1034 } else if (advise == MADV_DONTNEED) {
1035 vm_page_dontneed(m);
1036 } else if (advise == MADV_FREE) {
1037 /*
1038 * Mark the page clean. This will allow the page
1039 * to be freed up by the system. However, such pages
1040 * are often reused quickly by malloc()/free()
1041 * so we do not do anything that would cause
1042 * a page fault if we can help it.
1043 *
1044 * Specifically, we do not try to actually free
1045 * the page now nor do we try to put it in the
1046 * cache (which would cause a page fault on reuse).
1047 *
1048 * But we do make the page is freeable as we
1049 * can without actually taking the step of unmapping
1050 * it.
1051 */
1052 pmap_clear_modify(m);
1053 m->dirty = 0;
1054 m->act_count = 0;
1055 vm_page_dontneed(m);
1056 if (tobject->type == OBJT_SWAP)
1057 swap_pager_freespace(tobject, tpindex, 1);
1058 }
1059 }
1060}
1061
1062/*
1063 * vm_object_shadow:
1064 *
1065 * Create a new object which is backed by the
1066 * specified existing object range. The source
1067 * object reference is deallocated.
1068 *
1069 * The new object and offset into that object
1070 * are returned in the source parameters.
1071 */
1072void
1073vm_object_shadow(
1074 vm_object_t *object, /* IN/OUT */
1075 vm_ooffset_t *offset, /* IN/OUT */
1076 vm_size_t length)
1077{
1078 vm_object_t source;
1079 vm_object_t result;
1080
1081 GIANT_REQUIRED;
1082 source = *object;
1083
1084 /*
1085 * Don't create the new object if the old object isn't shared.
1086 */
1087 if (source != NULL &&
1088 source->ref_count == 1 &&
1089 source->handle == NULL &&
1090 (source->type == OBJT_DEFAULT ||
1091 source->type == OBJT_SWAP))
1092 return;
1093
1094 /*
1095 * Allocate a new object with the given length
1096 */
1097 result = vm_object_allocate(OBJT_DEFAULT, length);
1098 KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing"));
1099
1100 /*
1101 * The new object shadows the source object, adding a reference to it.
1102 * Our caller changes his reference to point to the new object,
1103 * removing a reference to the source object. Net result: no change
1104 * of reference count.
1105 *
1106 * Try to optimize the result object's page color when shadowing
1107 * in order to maintain page coloring consistency in the combined
1108 * shadowed object.
1109 */
1110 result->backing_object = source;
1111 if (source) {
1112 TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list);
1113 source->shadow_count++;
1114 source->generation++;
1115 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1116 }
1117
1118 /*
1119 * Store the offset into the source object, and fix up the offset into
1120 * the new object.
1121 */
1122 result->backing_object_offset = *offset;
1123
1124 /*
1125 * Return the new things
1126 */
1127 *offset = 0;
1128 *object = result;
1129}
1130
1131#define OBSC_TEST_ALL_SHADOWED 0x0001
1132#define OBSC_COLLAPSE_NOWAIT 0x0002
1133#define OBSC_COLLAPSE_WAIT 0x0004
1134
1135static __inline int
1136vm_object_backing_scan(vm_object_t object, int op)
1137{
1138 int s;
1139 int r = 1;
1140 vm_page_t p;
1141 vm_object_t backing_object;
1142 vm_pindex_t backing_offset_index;
1143
1144 s = splvm();
1145 GIANT_REQUIRED;
1146
1147 backing_object = object->backing_object;
1148 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1149
1150 /*
1151 * Initial conditions
1152 */
1153 if (op & OBSC_TEST_ALL_SHADOWED) {
1154 /*
1155 * We do not want to have to test for the existence of
1156 * swap pages in the backing object. XXX but with the
1157 * new swapper this would be pretty easy to do.
1158 *
1159 * XXX what about anonymous MAP_SHARED memory that hasn't
1160 * been ZFOD faulted yet? If we do not test for this, the
1161 * shadow test may succeed! XXX
1162 */
1163 if (backing_object->type != OBJT_DEFAULT) {
1164 splx(s);
1165 return (0);
1166 }
1167 }
1168 if (op & OBSC_COLLAPSE_WAIT) {
1169 vm_object_set_flag(backing_object, OBJ_DEAD);
1170 }
1171
1172 /*
1173 * Our scan
1174 */
1175 p = TAILQ_FIRST(&backing_object->memq);
1176 while (p) {
1177 vm_page_t next = TAILQ_NEXT(p, listq);
1178 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1179
1180 if (op & OBSC_TEST_ALL_SHADOWED) {
1181 vm_page_t pp;
1182
1183 /*
1184 * Ignore pages outside the parent object's range
1185 * and outside the parent object's mapping of the
1186 * backing object.
1187 *
1188 * note that we do not busy the backing object's
1189 * page.
1190 */
1191 if (
1192 p->pindex < backing_offset_index ||
1193 new_pindex >= object->size
1194 ) {
1195 p = next;
1196 continue;
1197 }
1198
1199 /*
1200 * See if the parent has the page or if the parent's
1201 * object pager has the page. If the parent has the
1202 * page but the page is not valid, the parent's
1203 * object pager must have the page.
1204 *
1205 * If this fails, the parent does not completely shadow
1206 * the object and we might as well give up now.
1207 */
1208
1209 pp = vm_page_lookup(object, new_pindex);
1210 if (
1211 (pp == NULL || pp->valid == 0) &&
1212 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1213 ) {
1214 r = 0;
1215 break;
1216 }
1217 }
1218
1219 /*
1220 * Check for busy page
1221 */
1222 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1223 vm_page_t pp;
1224
1225 if (op & OBSC_COLLAPSE_NOWAIT) {
1226 if (
1227 (p->flags & PG_BUSY) ||
1228 !p->valid ||
1229 p->hold_count ||
1230 p->wire_count ||
1231 p->busy
1232 ) {
1233 p = next;
1234 continue;
1235 }
1236 } else if (op & OBSC_COLLAPSE_WAIT) {
1237 if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1238 /*
1239 * If we slept, anything could have
1240 * happened. Since the object is
1241 * marked dead, the backing offset
1242 * should not have changed so we
1243 * just restart our scan.
1244 */
1245 p = TAILQ_FIRST(&backing_object->memq);
1246 continue;
1247 }
1248 }
1249
1250 /*
1251 * Busy the page
1252 */
1253 vm_page_busy(p);
1254
1255 KASSERT(
1256 p->object == backing_object,
1257 ("vm_object_qcollapse(): object mismatch")
1258 );
1259
1260 /*
1261 * Destroy any associated swap
1262 */
1263 if (backing_object->type == OBJT_SWAP) {
1264 swap_pager_freespace(
1265 backing_object,
1266 p->pindex,
1267 1
1268 );
1269 }
1270
1271 if (
1272 p->pindex < backing_offset_index ||
1273 new_pindex >= object->size
1274 ) {
1275 /*
1276 * Page is out of the parent object's range, we
1277 * can simply destroy it.
1278 */
1279 vm_page_protect(p, VM_PROT_NONE);
1280 vm_page_free(p);
1281 p = next;
1282 continue;
1283 }
1284
1285 pp = vm_page_lookup(object, new_pindex);
1286 if (
1287 pp != NULL ||
1288 vm_pager_has_page(object, new_pindex, NULL, NULL)
1289 ) {
1290 /*
1291 * page already exists in parent OR swap exists
1292 * for this location in the parent. Destroy
1293 * the original page from the backing object.
1294 *
1295 * Leave the parent's page alone
1296 */
1297 vm_page_protect(p, VM_PROT_NONE);
1298 vm_page_free(p);
1299 p = next;
1300 continue;
1301 }
1302
1303 /*
1304 * Page does not exist in parent, rename the
1305 * page from the backing object to the main object.
1306 *
1307 * If the page was mapped to a process, it can remain
1308 * mapped through the rename.
1309 */
1310 if ((p->queue - p->pc) == PQ_CACHE)
1311 vm_page_deactivate(p);
1312
1313 vm_page_rename(p, object, new_pindex);
1314 /* page automatically made dirty by rename */
1315 }
1316 p = next;
1317 }
1318 splx(s);
1319 return (r);
1320}
1321
1322
1323/*
1324 * this version of collapse allows the operation to occur earlier and
1325 * when paging_in_progress is true for an object... This is not a complete
1326 * operation, but should plug 99.9% of the rest of the leaks.
1327 */
1328static void
1329vm_object_qcollapse(vm_object_t object)
1330{
1331 vm_object_t backing_object = object->backing_object;
1332
1333 GIANT_REQUIRED;
1334
1335 if (backing_object->ref_count != 1)
1336 return;
1337
1338 backing_object->ref_count += 2;
1339
1340 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1341
1342 backing_object->ref_count -= 2;
1343}
1344
1345/*
1346 * vm_object_collapse:
1347 *
1348 * Collapse an object with the object backing it.
1349 * Pages in the backing object are moved into the
1350 * parent, and the backing object is deallocated.
1351 */
1352void
1353vm_object_collapse(vm_object_t object)
1354{
1355 GIANT_REQUIRED;
1356
1357 while (TRUE) {
1358 vm_object_t backing_object;
1359
1360 /*
1361 * Verify that the conditions are right for collapse:
1362 *
1363 * The object exists and the backing object exists.
1364 */
1365 if (object == NULL)
1366 break;
1367
1368 if ((backing_object = object->backing_object) == NULL)
1369 break;
1370
1371 /*
1372 * we check the backing object first, because it is most likely
1373 * not collapsable.
1374 */
1375 if (backing_object->handle != NULL ||
1376 (backing_object->type != OBJT_DEFAULT &&
1377 backing_object->type != OBJT_SWAP) ||
1378 (backing_object->flags & OBJ_DEAD) ||
1379 object->handle != NULL ||
1380 (object->type != OBJT_DEFAULT &&
1381 object->type != OBJT_SWAP) ||
1382 (object->flags & OBJ_DEAD)) {
1383 break;
1384 }
1385
1386 if (
1387 object->paging_in_progress != 0 ||
1388 backing_object->paging_in_progress != 0
1389 ) {
1390 vm_object_qcollapse(object);
1391 break;
1392 }
1393
1394 /*
1395 * We know that we can either collapse the backing object (if
1396 * the parent is the only reference to it) or (perhaps) have
1397 * the parent bypass the object if the parent happens to shadow
1398 * all the resident pages in the entire backing object.
1399 *
1400 * This is ignoring pager-backed pages such as swap pages.
1401 * vm_object_backing_scan fails the shadowing test in this
1402 * case.
1403 */
1404 if (backing_object->ref_count == 1) {
1405 /*
1406 * If there is exactly one reference to the backing
1407 * object, we can collapse it into the parent.
1408 */
1409 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1410
1411 /*
1412 * Move the pager from backing_object to object.
1413 */
1414 if (backing_object->type == OBJT_SWAP) {
1415 vm_object_pip_add(backing_object, 1);
1416
1417 /*
1418 * scrap the paging_offset junk and do a
1419 * discrete copy. This also removes major
1420 * assumptions about how the swap-pager
1421 * works from where it doesn't belong. The
1422 * new swapper is able to optimize the
1423 * destroy-source case.
1424 */
1425 vm_object_pip_add(object, 1);
1426 swap_pager_copy(
1427 backing_object,
1428 object,
1429 OFF_TO_IDX(object->backing_object_offset), TRUE);
1430 vm_object_pip_wakeup(object);
1431
1432 vm_object_pip_wakeup(backing_object);
1433 }
1434 /*
1435 * Object now shadows whatever backing_object did.
1436 * Note that the reference to
1437 * backing_object->backing_object moves from within
1438 * backing_object to within object.
1439 */
1440 TAILQ_REMOVE(
1441 &object->backing_object->shadow_head,
1442 object,
1443 shadow_list
1444 );
1445 object->backing_object->shadow_count--;
1446 object->backing_object->generation++;
1447 if (backing_object->backing_object) {
1448 TAILQ_REMOVE(
1449 &backing_object->backing_object->shadow_head,
1450 backing_object,
1451 shadow_list
1452 );
1453 backing_object->backing_object->shadow_count--;
1454 backing_object->backing_object->generation++;
1455 }
1456 object->backing_object = backing_object->backing_object;
1457 if (object->backing_object) {
1458 TAILQ_INSERT_TAIL(
1459 &object->backing_object->shadow_head,
1460 object,
1461 shadow_list
1462 );
1463 object->backing_object->shadow_count++;
1464 object->backing_object->generation++;
1465 }
1466
1467 object->backing_object_offset +=
1468 backing_object->backing_object_offset;
1469
1470 /*
1471 * Discard backing_object.
1472 *
1473 * Since the backing object has no pages, no pager left,
1474 * and no object references within it, all that is
1475 * necessary is to dispose of it.
1476 */
1477 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1478 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
1479
1480 TAILQ_REMOVE(
1481 &vm_object_list,
1482 backing_object,
1483 object_list
1484 );
1485
1486 zfree(obj_zone, backing_object);
1487
1488 object_collapses++;
1489 } else {
1490 vm_object_t new_backing_object;
1491
1492 /*
1493 * If we do not entirely shadow the backing object,
1494 * there is nothing we can do so we give up.
1495 */
1496 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1497 break;
1498 }
1499
1500 /*
1501 * Make the parent shadow the next object in the
1502 * chain. Deallocating backing_object will not remove
1503 * it, since its reference count is at least 2.
1504 */
1505 TAILQ_REMOVE(
1506 &backing_object->shadow_head,
1507 object,
1508 shadow_list
1509 );
1510 backing_object->shadow_count--;
1511 backing_object->generation++;
1512
1513 new_backing_object = backing_object->backing_object;
1514 if ((object->backing_object = new_backing_object) != NULL) {
1515 vm_object_reference(new_backing_object);
1516 TAILQ_INSERT_TAIL(
1517 &new_backing_object->shadow_head,
1518 object,
1519 shadow_list
1520 );
1521 new_backing_object->shadow_count++;
1522 new_backing_object->generation++;
1523 object->backing_object_offset +=
1524 backing_object->backing_object_offset;
1525 }
1526
1527 /*
1528 * Drop the reference count on backing_object. Since
1529 * its ref_count was at least 2, it will not vanish;
1530 * so we don't need to call vm_object_deallocate, but
1531 * we do anyway.
1532 */
1533 vm_object_deallocate(backing_object);
1534 object_bypasses++;
1535 }
1536
1537 /*
1538 * Try again with this object's new backing object.
1539 */
1540 }
1541}
1542
1543/*
1544 * vm_object_page_remove: [internal]
1545 *
1546 * Removes all physical pages in the specified
1547 * object range from the object's list of pages.
1548 *
1549 * The object must be locked.
1550 */
1551void
1552vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, boolean_t clean_only)
1553{
1554 vm_page_t p, next;
1555 unsigned int size;
1556 int all;
1557
1558 GIANT_REQUIRED;
1559
1560 if (object == NULL ||
1561 object->resident_page_count == 0)
1562 return;
1563
1564 all = ((end == 0) && (start == 0));
1565
1566 /*
1567 * Since physically-backed objects do not use managed pages, we can't
1568 * remove pages from the object (we must instead remove the page
1569 * references, and then destroy the object).
1570 */
1571 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object"));
1572
1573 vm_object_pip_add(object, 1);
1574again:
1575 size = end - start;
1576 if (all || size > object->resident_page_count / 4) {
1577 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
1578 next = TAILQ_NEXT(p, listq);
1579 if (all || ((start <= p->pindex) && (p->pindex < end))) {
1580 if (p->wire_count != 0) {
1581 vm_page_protect(p, VM_PROT_NONE);
1582 if (!clean_only)
1583 p->valid = 0;
1584 continue;
1585 }
1586
1587 /*
1588 * The busy flags are only cleared at
1589 * interrupt -- minimize the spl transitions
1590 */
1591 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1592 goto again;
1593
1594 if (clean_only && p->valid) {
1595 vm_page_test_dirty(p);
1596 if (p->valid & p->dirty)
1597 continue;
1598 }
1599
1600 vm_page_busy(p);
1601 vm_page_protect(p, VM_PROT_NONE);
1602 vm_page_free(p);
1603 }
1604 }
1605 } else {
1606 while (size > 0) {
1607 if ((p = vm_page_lookup(object, start)) != 0) {
1608
1609 if (p->wire_count != 0) {
1610 vm_page_protect(p, VM_PROT_NONE);
1611 if (!clean_only)
1612 p->valid = 0;
1613 start += 1;
1614 size -= 1;
1615 continue;
1616 }
1617
1618 /*
1619 * The busy flags are only cleared at
1620 * interrupt -- minimize the spl transitions
1621 */
1622 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1623 goto again;
1624
1625 if (clean_only && p->valid) {
1626 vm_page_test_dirty(p);
1627 if (p->valid & p->dirty) {
1628 start += 1;
1629 size -= 1;
1630 continue;
1631 }
1632 }
1633
1634 vm_page_busy(p);
1635 vm_page_protect(p, VM_PROT_NONE);
1636 vm_page_free(p);
1637 }
1638 start += 1;
1639 size -= 1;
1640 }
1641 }
1642 vm_object_pip_wakeup(object);
1643}
1644
1645/*
1646 * Routine: vm_object_coalesce
1647 * Function: Coalesces two objects backing up adjoining
1648 * regions of memory into a single object.
1649 *
1650 * returns TRUE if objects were combined.
1651 *
1652 * NOTE: Only works at the moment if the second object is NULL -
1653 * if it's not, which object do we lock first?
1654 *
1655 * Parameters:
1656 * prev_object First object to coalesce
1657 * prev_offset Offset into prev_object
1658 * next_object Second object into coalesce
1659 * next_offset Offset into next_object
1660 *
1661 * prev_size Size of reference to prev_object
1662 * next_size Size of reference to next_object
1663 *
1664 * Conditions:
1665 * The object must *not* be locked.
1666 */
1667boolean_t
1668vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size)
1669{
1670 vm_pindex_t next_pindex;
1671
1672 GIANT_REQUIRED;
1673
1674 if (prev_object == NULL) {
1675 return (TRUE);
1676 }
1677
1678 if (prev_object->type != OBJT_DEFAULT &&
1679 prev_object->type != OBJT_SWAP) {
1680 return (FALSE);
1681 }
1682
1683 /*
1684 * Try to collapse the object first
1685 */
1686 vm_object_collapse(prev_object);
1687
1688 /*
1689 * Can't coalesce if: . more than one reference . paged out . shadows
1690 * another object . has a copy elsewhere (any of which mean that the
1691 * pages not mapped to prev_entry may be in use anyway)
1692 */
1693 if (prev_object->backing_object != NULL) {
1694 return (FALSE);
1695 }
1696
1697 prev_size >>= PAGE_SHIFT;
1698 next_size >>= PAGE_SHIFT;
1699 next_pindex = prev_pindex + prev_size;
1700
1701 if ((prev_object->ref_count > 1) &&
1702 (prev_object->size != next_pindex)) {
1703 return (FALSE);
1704 }
1705
1706 /*
1707 * Remove any pages that may still be in the object from a previous
1708 * deallocation.
1709 */
1710 if (next_pindex < prev_object->size) {
1711 vm_object_page_remove(prev_object,
1712 next_pindex,
1713 next_pindex + next_size, FALSE);
1714 if (prev_object->type == OBJT_SWAP)
1715 swap_pager_freespace(prev_object,
1716 next_pindex, next_size);
1717 }
1718
1719 /*
1720 * Extend the object if necessary.
1721 */
1722 if (next_pindex + next_size > prev_object->size)
1723 prev_object->size = next_pindex + next_size;
1724
1725 return (TRUE);
1726}
1727
1728void
1729vm_object_set_writeable_dirty(vm_object_t object)
1730{
1731 struct vnode *vp;
1732
1733 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1734 if (object->type == OBJT_VNODE &&
1735 (vp = (struct vnode *)object->handle) != NULL) {
1736 if ((vp->v_flag & VOBJDIRTY) == 0) {
1737 mtx_lock(&vp->v_interlock);
1738 vp->v_flag |= VOBJDIRTY;
1739 mtx_unlock(&vp->v_interlock);
1740 }
1741 }
1742}
1743
1744#include "opt_ddb.h"
1745#ifdef DDB
1746#include <sys/kernel.h>
1747
1748#include <sys/cons.h>
1749
1750#include <ddb/ddb.h>
1751
1752static int
1753_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1754{
1755 vm_map_t tmpm;
1756 vm_map_entry_t tmpe;
1757 vm_object_t obj;
1758 int entcount;
1759
1760 if (map == 0)
1761 return 0;
1762
1763 if (entry == 0) {
1764 tmpe = map->header.next;
1765 entcount = map->nentries;
1766 while (entcount-- && (tmpe != &map->header)) {
1767 if (_vm_object_in_map(map, object, tmpe)) {
1768 return 1;
1769 }
1770 tmpe = tmpe->next;
1771 }
1772 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1773 tmpm = entry->object.sub_map;
1774 tmpe = tmpm->header.next;
1775 entcount = tmpm->nentries;
1776 while (entcount-- && tmpe != &tmpm->header) {
1777 if (_vm_object_in_map(tmpm, object, tmpe)) {
1778 return 1;
1779 }
1780 tmpe = tmpe->next;
1781 }
1782 } else if ((obj = entry->object.vm_object) != NULL) {
1783 for (; obj; obj = obj->backing_object)
1784 if (obj == object) {
1785 return 1;
1786 }
1787 }
1788 return 0;
1789}
1790
1791static int
1792vm_object_in_map(vm_object_t object)
1793{
1794 struct proc *p;
1795
1796 /* sx_slock(&allproc_lock); */
1797 LIST_FOREACH(p, &allproc, p_list) {
1798 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1799 continue;
1800 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1801 /* sx_sunlock(&allproc_lock); */
1802 return 1;
1803 }
1804 }
1805 /* sx_sunlock(&allproc_lock); */
1806 if (_vm_object_in_map(kernel_map, object, 0))
1807 return 1;
1808 if (_vm_object_in_map(kmem_map, object, 0))
1809 return 1;
1810 if (_vm_object_in_map(pager_map, object, 0))
1811 return 1;
1812 if (_vm_object_in_map(buffer_map, object, 0))
1813 return 1;
1814 return 0;
1815}
1816
1817DB_SHOW_COMMAND(vmochk, vm_object_check)
1818{
1819 vm_object_t object;
1820
1821 /*
1822 * make sure that internal objs are in a map somewhere
1823 * and none have zero ref counts.
1824 */
1825 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1826 if (object->handle == NULL &&
1827 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
1828 if (object->ref_count == 0) {
1829 db_printf("vmochk: internal obj has zero ref count: %ld\n",
1830 (long)object->size);
1831 }
1832 if (!vm_object_in_map(object)) {
1833 db_printf(
1834 "vmochk: internal obj is not in a map: "
1835 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
1836 object->ref_count, (u_long)object->size,
1837 (u_long)object->size,
1838 (void *)object->backing_object);
1839 }
1840 }
1841 }
1842}
1843
1844/*
1845 * vm_object_print: [ debug ]
1846 */
1847DB_SHOW_COMMAND(object, vm_object_print_static)
1848{
1849 /* XXX convert args. */
1850 vm_object_t object = (vm_object_t)addr;
1851 boolean_t full = have_addr;
1852
1853 vm_page_t p;
1854
1855 /* XXX count is an (unused) arg. Avoid shadowing it. */
1856#define count was_count
1857
1858 int count;
1859
1860 if (object == NULL)
1861 return;
1862
1863 db_iprintf(
1864 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
1865 object, (int)object->type, (u_long)object->size,
1866 object->resident_page_count, object->ref_count, object->flags);
1867 /*
1868 * XXX no %qd in kernel. Truncate object->backing_object_offset.
1869 */
1870 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
1871 object->shadow_count,
1872 object->backing_object ? object->backing_object->ref_count : 0,
1873 object->backing_object, (long)object->backing_object_offset);
1874
1875 if (!full)
1876 return;
1877
1878 db_indent += 2;
1879 count = 0;
1880 TAILQ_FOREACH(p, &object->memq, listq) {
1881 if (count == 0)
1882 db_iprintf("memory:=");
1883 else if (count == 6) {
1884 db_printf("\n");
1885 db_iprintf(" ...");
1886 count = 0;
1887 } else
1888 db_printf(",");
1889 count++;
1890
1891 db_printf("(off=0x%lx,page=0x%lx)",
1892 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
1893 }
1894 if (count != 0)
1895 db_printf("\n");
1896 db_indent -= 2;
1897}
1898
1899/* XXX. */
1900#undef count
1901
1902/* XXX need this non-static entry for calling from vm_map_print. */
1903void
1904vm_object_print(
1905 /* db_expr_t */ long addr,
1906 boolean_t have_addr,
1907 /* db_expr_t */ long count,
1908 char *modif)
1909{
1910 vm_object_print_static(addr, have_addr, count, modif);
1911}
1912
1913DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
1914{
1915 vm_object_t object;
1916 int nl = 0;
1917 int c;
1918
1919 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1920 vm_pindex_t idx, fidx;
1921 vm_pindex_t osize;
1922 vm_offset_t pa = -1, padiff;
1923 int rcount;
1924 vm_page_t m;
1925
1926 db_printf("new object: %p\n", (void *)object);
1927 if (nl > 18) {
1928 c = cngetc();
1929 if (c != ' ')
1930 return;
1931 nl = 0;
1932 }
1933 nl++;
1934 rcount = 0;
1935 fidx = 0;
1936 osize = object->size;
1937 if (osize > 128)
1938 osize = 128;
1939 for (idx = 0; idx < osize; idx++) {
1940 m = vm_page_lookup(object, idx);
1941 if (m == NULL) {
1942 if (rcount) {
1943 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1944 (long)fidx, rcount, (long)pa);
1945 if (nl > 18) {
1946 c = cngetc();
1947 if (c != ' ')
1948 return;
1949 nl = 0;
1950 }
1951 nl++;
1952 rcount = 0;
1953 }
1954 continue;
1955 }
1956
1957
1958 if (rcount &&
1959 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
1960 ++rcount;
1961 continue;
1962 }
1963 if (rcount) {
1964 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
1965 padiff >>= PAGE_SHIFT;
1966 padiff &= PQ_L2_MASK;
1967 if (padiff == 0) {
1968 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
1969 ++rcount;
1970 continue;
1971 }
1972 db_printf(" index(%ld)run(%d)pa(0x%lx)",
1973 (long)fidx, rcount, (long)pa);
1974 db_printf("pd(%ld)\n", (long)padiff);
1975 if (nl > 18) {
1976 c = cngetc();
1977 if (c != ' ')
1978 return;
1979 nl = 0;
1980 }
1981 nl++;
1982 }
1983 fidx = idx;
1984 pa = VM_PAGE_TO_PHYS(m);
1985 rcount = 1;
1986 }
1987 if (rcount) {
1988 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1989 (long)fidx, rcount, (long)pa);
1990 if (nl > 18) {
1991 c = cngetc();
1992 if (c != ' ')
1993 return;
1994 nl = 0;
1995 }
1996 nl++;
1997 }
1998 }
1999}
2000#endif /* DDB */
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94
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 * $FreeBSD: head/sys/vm/vm_object.c 92511 2002-03-17 18:37:37Z alc $
65 */
66
67/*
68 * Virtual memory object module.
69 */
70
71#include <sys/param.h>
72#include <sys/systm.h>
73#include <sys/lock.h>
74#include <sys/mman.h>
75#include <sys/mount.h>
76#include <sys/kernel.h>
77#include <sys/sysctl.h>
78#include <sys/mutex.h>
79#include <sys/proc.h> /* for curproc, pageproc */
80#include <sys/socket.h>
81#include <sys/vnode.h>
82#include <sys/vmmeter.h>
83#include <sys/sx.h>
84
85#include <vm/vm.h>
86#include <vm/vm_param.h>
87#include <vm/pmap.h>
88#include <vm/vm_map.h>
89#include <vm/vm_object.h>
90#include <vm/vm_page.h>
91#include <vm/vm_pageout.h>
92#include <vm/vm_pager.h>
93#include <vm/vm_zone.h>
94#include <vm/swap_pager.h>
95#include <vm/vm_kern.h>
96#include <vm/vm_extern.h>
97
98#define EASY_SCAN_FACTOR 8
99
100#define MSYNC_FLUSH_HARDSEQ 0x01
101#define MSYNC_FLUSH_SOFTSEQ 0x02
102
103/*
104 * msync / VM object flushing optimizations
105 */
106static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ;
107SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags,
108 CTLFLAG_RW, &msync_flush_flags, 0, "");
109
110static void vm_object_qcollapse(vm_object_t object);
111static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags);
112
113/*
114 * Virtual memory objects maintain the actual data
115 * associated with allocated virtual memory. A given
116 * page of memory exists within exactly one object.
117 *
118 * An object is only deallocated when all "references"
119 * are given up. Only one "reference" to a given
120 * region of an object should be writeable.
121 *
122 * Associated with each object is a list of all resident
123 * memory pages belonging to that object; this list is
124 * maintained by the "vm_page" module, and locked by the object's
125 * lock.
126 *
127 * Each object also records a "pager" routine which is
128 * used to retrieve (and store) pages to the proper backing
129 * storage. In addition, objects may be backed by other
130 * objects from which they were virtual-copied.
131 *
132 * The only items within the object structure which are
133 * modified after time of creation are:
134 * reference count locked by object's lock
135 * pager routine locked by object's lock
136 *
137 */
138
139struct object_q vm_object_list;
140static struct mtx vm_object_list_mtx; /* lock for object list and count */
141vm_object_t kernel_object;
142vm_object_t kmem_object;
143static struct vm_object kernel_object_store;
144static struct vm_object kmem_object_store;
145extern int vm_pageout_page_count;
146
147static long object_collapses;
148static long object_bypasses;
149static int next_index;
150static vm_zone_t obj_zone;
151static struct vm_zone obj_zone_store;
152static int object_hash_rand;
153#define VM_OBJECTS_INIT 256
154static struct vm_object vm_objects_init[VM_OBJECTS_INIT];
155
156void
157_vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object)
158{
159 int incr;
160
161 GIANT_REQUIRED;
162
163 TAILQ_INIT(&object->memq);
164 TAILQ_INIT(&object->shadow_head);
165
166 object->type = type;
167 object->size = size;
168 object->ref_count = 1;
169 object->flags = 0;
170 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
171 vm_object_set_flag(object, OBJ_ONEMAPPING);
172 object->paging_in_progress = 0;
173 object->resident_page_count = 0;
174 object->shadow_count = 0;
175 object->pg_color = next_index;
176 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
177 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
178 else
179 incr = size;
180 next_index = (next_index + incr) & PQ_L2_MASK;
181 object->handle = NULL;
182 object->backing_object = NULL;
183 object->backing_object_offset = (vm_ooffset_t) 0;
184 /*
185 * Try to generate a number that will spread objects out in the
186 * hash table. We 'wipe' new objects across the hash in 128 page
187 * increments plus 1 more to offset it a little more by the time
188 * it wraps around.
189 */
190 object->hash_rand = object_hash_rand - 129;
191
192 object->generation++;
193
194 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
195
196 object_hash_rand = object->hash_rand;
197}
198
199/*
200 * vm_object_init:
201 *
202 * Initialize the VM objects module.
203 */
204void
205vm_object_init(void)
206{
207 GIANT_REQUIRED;
208
209 TAILQ_INIT(&vm_object_list);
210 mtx_init(&vm_object_list_mtx, "vm object_list", MTX_DEF);
211
212 kernel_object = &kernel_object_store;
213 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
214 kernel_object);
215
216 kmem_object = &kmem_object_store;
217 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
218 kmem_object);
219
220 obj_zone = &obj_zone_store;
221 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object),
222 vm_objects_init, VM_OBJECTS_INIT);
223}
224
225void
226vm_object_init2(void)
227{
228 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1);
229}
230
231void
232vm_object_set_flag(vm_object_t object, u_short bits)
233{
234 GIANT_REQUIRED;
235 object->flags |= bits;
236}
237
238void
239vm_object_clear_flag(vm_object_t object, u_short bits)
240{
241 GIANT_REQUIRED;
242 object->flags &= ~bits;
243}
244
245void
246vm_object_pip_add(vm_object_t object, short i)
247{
248 GIANT_REQUIRED;
249 object->paging_in_progress += i;
250}
251
252void
253vm_object_pip_subtract(vm_object_t object, short i)
254{
255 GIANT_REQUIRED;
256 object->paging_in_progress -= i;
257}
258
259void
260vm_object_pip_wakeup(vm_object_t object)
261{
262 GIANT_REQUIRED;
263 object->paging_in_progress--;
264 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
265 vm_object_clear_flag(object, OBJ_PIPWNT);
266 wakeup(object);
267 }
268}
269
270void
271vm_object_pip_wakeupn(vm_object_t object, short i)
272{
273 GIANT_REQUIRED;
274 if (i)
275 object->paging_in_progress -= i;
276 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
277 vm_object_clear_flag(object, OBJ_PIPWNT);
278 wakeup(object);
279 }
280}
281
282void
283vm_object_pip_sleep(vm_object_t object, char *waitid)
284{
285 GIANT_REQUIRED;
286 if (object->paging_in_progress) {
287 int s = splvm();
288 if (object->paging_in_progress) {
289 vm_object_set_flag(object, OBJ_PIPWNT);
290 tsleep(object, PVM, waitid, 0);
291 }
292 splx(s);
293 }
294}
295
296void
297vm_object_pip_wait(vm_object_t object, char *waitid)
298{
299 GIANT_REQUIRED;
300 while (object->paging_in_progress)
301 vm_object_pip_sleep(object, waitid);
302}
303
304/*
305 * vm_object_allocate:
306 *
307 * Returns a new object with the given size.
308 */
309vm_object_t
310vm_object_allocate(objtype_t type, vm_size_t size)
311{
312 vm_object_t result;
313
314 GIANT_REQUIRED;
315
316 result = (vm_object_t) zalloc(obj_zone);
317 _vm_object_allocate(type, size, result);
318
319 return (result);
320}
321
322
323/*
324 * vm_object_reference:
325 *
326 * Gets another reference to the given object.
327 */
328void
329vm_object_reference(vm_object_t object)
330{
331 GIANT_REQUIRED;
332
333 if (object == NULL)
334 return;
335
336#if 0
337 /* object can be re-referenced during final cleaning */
338 KASSERT(!(object->flags & OBJ_DEAD),
339 ("vm_object_reference: attempting to reference dead obj"));
340#endif
341
342 object->ref_count++;
343 if (object->type == OBJT_VNODE) {
344 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) {
345 printf("vm_object_reference: delay in getting object\n");
346 }
347 }
348}
349
350/*
351 * handle deallocating a object of type OBJT_VNODE
352 */
353void
354vm_object_vndeallocate(vm_object_t object)
355{
356 struct vnode *vp = (struct vnode *) object->handle;
357
358 GIANT_REQUIRED;
359 KASSERT(object->type == OBJT_VNODE,
360 ("vm_object_vndeallocate: not a vnode object"));
361 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
362#ifdef INVARIANTS
363 if (object->ref_count == 0) {
364 vprint("vm_object_vndeallocate", vp);
365 panic("vm_object_vndeallocate: bad object reference count");
366 }
367#endif
368
369 object->ref_count--;
370 if (object->ref_count == 0) {
371 vp->v_flag &= ~VTEXT;
372 vm_object_clear_flag(object, OBJ_OPT);
373 }
374 /*
375 * vrele may need a vop lock
376 */
377 vrele(vp);
378}
379
380/*
381 * vm_object_deallocate:
382 *
383 * Release a reference to the specified object,
384 * gained either through a vm_object_allocate
385 * or a vm_object_reference call. When all references
386 * are gone, storage associated with this object
387 * may be relinquished.
388 *
389 * No object may be locked.
390 */
391void
392vm_object_deallocate(vm_object_t object)
393{
394 vm_object_t temp;
395
396 GIANT_REQUIRED;
397
398 while (object != NULL) {
399
400 if (object->type == OBJT_VNODE) {
401 vm_object_vndeallocate(object);
402 return;
403 }
404
405 KASSERT(object->ref_count != 0,
406 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
407
408 /*
409 * If the reference count goes to 0 we start calling
410 * vm_object_terminate() on the object chain.
411 * A ref count of 1 may be a special case depending on the
412 * shadow count being 0 or 1.
413 */
414 object->ref_count--;
415 if (object->ref_count > 1) {
416 return;
417 } else if (object->ref_count == 1) {
418 if (object->shadow_count == 0) {
419 vm_object_set_flag(object, OBJ_ONEMAPPING);
420 } else if ((object->shadow_count == 1) &&
421 (object->handle == NULL) &&
422 (object->type == OBJT_DEFAULT ||
423 object->type == OBJT_SWAP)) {
424 vm_object_t robject;
425
426 robject = TAILQ_FIRST(&object->shadow_head);
427 KASSERT(robject != NULL,
428 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
429 object->ref_count,
430 object->shadow_count));
431 if ((robject->handle == NULL) &&
432 (robject->type == OBJT_DEFAULT ||
433 robject->type == OBJT_SWAP)) {
434
435 robject->ref_count++;
436
437 while (
438 robject->paging_in_progress ||
439 object->paging_in_progress
440 ) {
441 vm_object_pip_sleep(robject, "objde1");
442 vm_object_pip_sleep(object, "objde2");
443 }
444
445 if (robject->ref_count == 1) {
446 robject->ref_count--;
447 object = robject;
448 goto doterm;
449 }
450
451 object = robject;
452 vm_object_collapse(object);
453 continue;
454 }
455 }
456
457 return;
458
459 }
460
461doterm:
462
463 temp = object->backing_object;
464 if (temp) {
465 TAILQ_REMOVE(&temp->shadow_head, object, shadow_list);
466 temp->shadow_count--;
467 if (temp->ref_count == 0)
468 vm_object_clear_flag(temp, OBJ_OPT);
469 temp->generation++;
470 object->backing_object = NULL;
471 }
472 /*
473 * Don't double-terminate, we could be in a termination
474 * recursion due to the terminate having to sync data
475 * to disk.
476 */
477 if ((object->flags & OBJ_DEAD) == 0)
478 vm_object_terminate(object);
479 object = temp;
480 }
481}
482
483/*
484 * vm_object_terminate actually destroys the specified object, freeing
485 * up all previously used resources.
486 *
487 * The object must be locked.
488 * This routine may block.
489 */
490void
491vm_object_terminate(vm_object_t object)
492{
493 vm_page_t p;
494 int s;
495
496 GIANT_REQUIRED;
497
498 /*
499 * Make sure no one uses us.
500 */
501 vm_object_set_flag(object, OBJ_DEAD);
502
503 /*
504 * wait for the pageout daemon to be done with the object
505 */
506 vm_object_pip_wait(object, "objtrm");
507
508 KASSERT(!object->paging_in_progress,
509 ("vm_object_terminate: pageout in progress"));
510
511 /*
512 * Clean and free the pages, as appropriate. All references to the
513 * object are gone, so we don't need to lock it.
514 */
515 if (object->type == OBJT_VNODE) {
516 struct vnode *vp;
517
518 /*
519 * Freeze optimized copies.
520 */
521 vm_freeze_copyopts(object, 0, object->size);
522
523 /*
524 * Clean pages and flush buffers.
525 */
526 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
527
528 vp = (struct vnode *) object->handle;
529 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
530 }
531
532 KASSERT(object->ref_count == 0,
533 ("vm_object_terminate: object with references, ref_count=%d",
534 object->ref_count));
535
536 /*
537 * Now free any remaining pages. For internal objects, this also
538 * removes them from paging queues. Don't free wired pages, just
539 * remove them from the object.
540 */
541 s = splvm();
542 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
543 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
544 ("vm_object_terminate: freeing busy page %p "
545 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
546 if (p->wire_count == 0) {
547 vm_page_busy(p);
548 vm_page_free(p);
549 cnt.v_pfree++;
550 } else {
551 vm_page_busy(p);
552 vm_page_remove(p);
553 }
554 }
555 splx(s);
556
557 /*
558 * Let the pager know object is dead.
559 */
560 vm_pager_deallocate(object);
561
562 /*
563 * Remove the object from the global object list.
564 */
565 mtx_lock(&vm_object_list_mtx);
566 TAILQ_REMOVE(&vm_object_list, object, object_list);
567 mtx_unlock(&vm_object_list_mtx);
568
569 wakeup(object);
570
571 /*
572 * Free the space for the object.
573 */
574 zfree(obj_zone, object);
575}
576
577/*
578 * vm_object_page_clean
579 *
580 * Clean all dirty pages in the specified range of object. Leaves page
581 * on whatever queue it is currently on. If NOSYNC is set then do not
582 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
583 * leaving the object dirty.
584 *
585 * Odd semantics: if start == end, we clean everything.
586 *
587 * The object must be locked.
588 */
589void
590vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
591{
592 vm_page_t p, np;
593 vm_offset_t tstart, tend;
594 vm_pindex_t pi;
595 struct vnode *vp;
596 int clearobjflags;
597 int pagerflags;
598 int curgeneration;
599
600 GIANT_REQUIRED;
601
602 if (object->type != OBJT_VNODE ||
603 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
604 return;
605
606 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : 0;
607 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
608
609 vp = object->handle;
610
611 vm_object_set_flag(object, OBJ_CLEANING);
612
613 tstart = start;
614 if (end == 0) {
615 tend = object->size;
616 } else {
617 tend = end;
618 }
619
620 /*
621 * If the caller is smart and only msync()s a range he knows is
622 * dirty, we may be able to avoid an object scan. This results in
623 * a phenominal improvement in performance. We cannot do this
624 * as a matter of course because the object may be huge - e.g.
625 * the size might be in the gigabytes or terrabytes.
626 */
627 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
628 vm_offset_t tscan;
629 int scanlimit;
630 int scanreset;
631
632 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
633 if (scanreset < 16)
634 scanreset = 16;
635
636 scanlimit = scanreset;
637 tscan = tstart;
638 while (tscan < tend) {
639 curgeneration = object->generation;
640 p = vm_page_lookup(object, tscan);
641 if (p == NULL || p->valid == 0 ||
642 (p->queue - p->pc) == PQ_CACHE) {
643 if (--scanlimit == 0)
644 break;
645 ++tscan;
646 continue;
647 }
648 vm_page_test_dirty(p);
649 if ((p->dirty & p->valid) == 0) {
650 if (--scanlimit == 0)
651 break;
652 ++tscan;
653 continue;
654 }
655 /*
656 * If we have been asked to skip nosync pages and
657 * this is a nosync page, we can't continue.
658 */
659 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
660 if (--scanlimit == 0)
661 break;
662 ++tscan;
663 continue;
664 }
665 scanlimit = scanreset;
666
667 /*
668 * This returns 0 if it was unable to busy the first
669 * page (i.e. had to sleep).
670 */
671 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
672 }
673
674 /*
675 * If everything was dirty and we flushed it successfully,
676 * and the requested range is not the entire object, we
677 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
678 * return immediately.
679 */
680 if (tscan >= tend && (tstart || tend < object->size)) {
681 vm_object_clear_flag(object, OBJ_CLEANING);
682 return;
683 }
684 }
685
686 /*
687 * Generally set CLEANCHK interlock and make the page read-only so
688 * we can then clear the object flags.
689 *
690 * However, if this is a nosync mmap then the object is likely to
691 * stay dirty so do not mess with the page and do not clear the
692 * object flags.
693 */
694 clearobjflags = 1;
695
696 TAILQ_FOREACH(p, &object->memq, listq) {
697 vm_page_flag_set(p, PG_CLEANCHK);
698 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
699 clearobjflags = 0;
700 else
701 vm_page_protect(p, VM_PROT_READ);
702 }
703
704 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
705 struct vnode *vp;
706
707 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
708 if (object->type == OBJT_VNODE &&
709 (vp = (struct vnode *)object->handle) != NULL) {
710 if (vp->v_flag & VOBJDIRTY) {
711 mtx_lock(&vp->v_interlock);
712 vp->v_flag &= ~VOBJDIRTY;
713 mtx_unlock(&vp->v_interlock);
714 }
715 }
716 }
717
718rescan:
719 curgeneration = object->generation;
720
721 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
722 int n;
723
724 np = TAILQ_NEXT(p, listq);
725
726again:
727 pi = p->pindex;
728 if (((p->flags & PG_CLEANCHK) == 0) ||
729 (pi < tstart) || (pi >= tend) ||
730 (p->valid == 0) ||
731 ((p->queue - p->pc) == PQ_CACHE)) {
732 vm_page_flag_clear(p, PG_CLEANCHK);
733 continue;
734 }
735
736 vm_page_test_dirty(p);
737 if ((p->dirty & p->valid) == 0) {
738 vm_page_flag_clear(p, PG_CLEANCHK);
739 continue;
740 }
741
742 /*
743 * If we have been asked to skip nosync pages and this is a
744 * nosync page, skip it. Note that the object flags were
745 * not cleared in this case so we do not have to set them.
746 */
747 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
748 vm_page_flag_clear(p, PG_CLEANCHK);
749 continue;
750 }
751
752 n = vm_object_page_collect_flush(object, p,
753 curgeneration, pagerflags);
754 if (n == 0)
755 goto rescan;
756
757 if (object->generation != curgeneration)
758 goto rescan;
759
760 /*
761 * Try to optimize the next page. If we can't we pick up
762 * our (random) scan where we left off.
763 */
764 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
765 if ((p = vm_page_lookup(object, pi + n)) != NULL)
766 goto again;
767 }
768 }
769
770#if 0
771 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
772#endif
773
774 vm_object_clear_flag(object, OBJ_CLEANING);
775 return;
776}
777
778static int
779vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
780{
781 int runlen;
782 int s;
783 int maxf;
784 int chkb;
785 int maxb;
786 int i;
787 vm_pindex_t pi;
788 vm_page_t maf[vm_pageout_page_count];
789 vm_page_t mab[vm_pageout_page_count];
790 vm_page_t ma[vm_pageout_page_count];
791
792 s = splvm();
793 pi = p->pindex;
794 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
795 if (object->generation != curgeneration) {
796 splx(s);
797 return(0);
798 }
799 }
800
801 maxf = 0;
802 for(i = 1; i < vm_pageout_page_count; i++) {
803 vm_page_t tp;
804
805 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
806 if ((tp->flags & PG_BUSY) ||
807 (tp->flags & PG_CLEANCHK) == 0 ||
808 (tp->busy != 0))
809 break;
810 if((tp->queue - tp->pc) == PQ_CACHE) {
811 vm_page_flag_clear(tp, PG_CLEANCHK);
812 break;
813 }
814 vm_page_test_dirty(tp);
815 if ((tp->dirty & tp->valid) == 0) {
816 vm_page_flag_clear(tp, PG_CLEANCHK);
817 break;
818 }
819 maf[ i - 1 ] = tp;
820 maxf++;
821 continue;
822 }
823 break;
824 }
825
826 maxb = 0;
827 chkb = vm_pageout_page_count - maxf;
828 if (chkb) {
829 for(i = 1; i < chkb;i++) {
830 vm_page_t tp;
831
832 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
833 if ((tp->flags & PG_BUSY) ||
834 (tp->flags & PG_CLEANCHK) == 0 ||
835 (tp->busy != 0))
836 break;
837 if ((tp->queue - tp->pc) == PQ_CACHE) {
838 vm_page_flag_clear(tp, PG_CLEANCHK);
839 break;
840 }
841 vm_page_test_dirty(tp);
842 if ((tp->dirty & tp->valid) == 0) {
843 vm_page_flag_clear(tp, PG_CLEANCHK);
844 break;
845 }
846 mab[ i - 1 ] = tp;
847 maxb++;
848 continue;
849 }
850 break;
851 }
852 }
853
854 for(i = 0; i < maxb; i++) {
855 int index = (maxb - i) - 1;
856 ma[index] = mab[i];
857 vm_page_flag_clear(ma[index], PG_CLEANCHK);
858 }
859 vm_page_flag_clear(p, PG_CLEANCHK);
860 ma[maxb] = p;
861 for(i = 0; i < maxf; i++) {
862 int index = (maxb + i) + 1;
863 ma[index] = maf[i];
864 vm_page_flag_clear(ma[index], PG_CLEANCHK);
865 }
866 runlen = maxb + maxf + 1;
867
868 splx(s);
869 vm_pageout_flush(ma, runlen, pagerflags);
870 for (i = 0; i < runlen; i++) {
871 if (ma[i]->valid & ma[i]->dirty) {
872 vm_page_protect(ma[i], VM_PROT_READ);
873 vm_page_flag_set(ma[i], PG_CLEANCHK);
874
875 /*
876 * maxf will end up being the actual number of pages
877 * we wrote out contiguously, non-inclusive of the
878 * first page. We do not count look-behind pages.
879 */
880 if (i >= maxb + 1 && (maxf > i - maxb - 1))
881 maxf = i - maxb - 1;
882 }
883 }
884 return(maxf + 1);
885}
886
887/*
888 * Same as vm_object_pmap_copy, except range checking really
889 * works, and is meant for small sections of an object.
890 *
891 * This code protects resident pages by making them read-only
892 * and is typically called on a fork or split when a page
893 * is converted to copy-on-write.
894 *
895 * NOTE: If the page is already at VM_PROT_NONE, calling
896 * vm_page_protect will have no effect.
897 */
898void
899vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
900{
901 vm_pindex_t idx;
902 vm_page_t p;
903
904 GIANT_REQUIRED;
905
906 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
907 return;
908
909 for (idx = start; idx < end; idx++) {
910 p = vm_page_lookup(object, idx);
911 if (p == NULL)
912 continue;
913 vm_page_protect(p, VM_PROT_READ);
914 }
915}
916
917/*
918 * vm_object_pmap_remove:
919 *
920 * Removes all physical pages in the specified
921 * object range from all physical maps.
922 *
923 * The object must *not* be locked.
924 */
925void
926vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
927{
928 vm_page_t p;
929
930 GIANT_REQUIRED;
931 if (object == NULL)
932 return;
933 TAILQ_FOREACH(p, &object->memq, listq) {
934 if (p->pindex >= start && p->pindex < end)
935 vm_page_protect(p, VM_PROT_NONE);
936 }
937 if ((start == 0) && (object->size == end))
938 vm_object_clear_flag(object, OBJ_WRITEABLE);
939}
940
941/*
942 * vm_object_madvise:
943 *
944 * Implements the madvise function at the object/page level.
945 *
946 * MADV_WILLNEED (any object)
947 *
948 * Activate the specified pages if they are resident.
949 *
950 * MADV_DONTNEED (any object)
951 *
952 * Deactivate the specified pages if they are resident.
953 *
954 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
955 * OBJ_ONEMAPPING only)
956 *
957 * Deactivate and clean the specified pages if they are
958 * resident. This permits the process to reuse the pages
959 * without faulting or the kernel to reclaim the pages
960 * without I/O.
961 */
962void
963vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
964{
965 vm_pindex_t end, tpindex;
966 vm_object_t tobject;
967 vm_page_t m;
968
969 GIANT_REQUIRED;
970 if (object == NULL)
971 return;
972
973 end = pindex + count;
974
975 /*
976 * Locate and adjust resident pages
977 */
978 for (; pindex < end; pindex += 1) {
979relookup:
980 tobject = object;
981 tpindex = pindex;
982shadowlookup:
983 /*
984 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
985 * and those pages must be OBJ_ONEMAPPING.
986 */
987 if (advise == MADV_FREE) {
988 if ((tobject->type != OBJT_DEFAULT &&
989 tobject->type != OBJT_SWAP) ||
990 (tobject->flags & OBJ_ONEMAPPING) == 0) {
991 continue;
992 }
993 }
994
995 m = vm_page_lookup(tobject, tpindex);
996
997 if (m == NULL) {
998 /*
999 * There may be swap even if there is no backing page
1000 */
1001 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1002 swap_pager_freespace(tobject, tpindex, 1);
1003
1004 /*
1005 * next object
1006 */
1007 tobject = tobject->backing_object;
1008 if (tobject == NULL)
1009 continue;
1010 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1011 goto shadowlookup;
1012 }
1013
1014 /*
1015 * If the page is busy or not in a normal active state,
1016 * we skip it. If the page is not managed there are no
1017 * page queues to mess with. Things can break if we mess
1018 * with pages in any of the below states.
1019 */
1020 if (
1021 m->hold_count ||
1022 m->wire_count ||
1023 (m->flags & PG_UNMANAGED) ||
1024 m->valid != VM_PAGE_BITS_ALL
1025 ) {
1026 continue;
1027 }
1028
1029 if (vm_page_sleep_busy(m, TRUE, "madvpo"))
1030 goto relookup;
1031
1032 if (advise == MADV_WILLNEED) {
1033 vm_page_activate(m);
1034 } else if (advise == MADV_DONTNEED) {
1035 vm_page_dontneed(m);
1036 } else if (advise == MADV_FREE) {
1037 /*
1038 * Mark the page clean. This will allow the page
1039 * to be freed up by the system. However, such pages
1040 * are often reused quickly by malloc()/free()
1041 * so we do not do anything that would cause
1042 * a page fault if we can help it.
1043 *
1044 * Specifically, we do not try to actually free
1045 * the page now nor do we try to put it in the
1046 * cache (which would cause a page fault on reuse).
1047 *
1048 * But we do make the page is freeable as we
1049 * can without actually taking the step of unmapping
1050 * it.
1051 */
1052 pmap_clear_modify(m);
1053 m->dirty = 0;
1054 m->act_count = 0;
1055 vm_page_dontneed(m);
1056 if (tobject->type == OBJT_SWAP)
1057 swap_pager_freespace(tobject, tpindex, 1);
1058 }
1059 }
1060}
1061
1062/*
1063 * vm_object_shadow:
1064 *
1065 * Create a new object which is backed by the
1066 * specified existing object range. The source
1067 * object reference is deallocated.
1068 *
1069 * The new object and offset into that object
1070 * are returned in the source parameters.
1071 */
1072void
1073vm_object_shadow(
1074 vm_object_t *object, /* IN/OUT */
1075 vm_ooffset_t *offset, /* IN/OUT */
1076 vm_size_t length)
1077{
1078 vm_object_t source;
1079 vm_object_t result;
1080
1081 GIANT_REQUIRED;
1082 source = *object;
1083
1084 /*
1085 * Don't create the new object if the old object isn't shared.
1086 */
1087 if (source != NULL &&
1088 source->ref_count == 1 &&
1089 source->handle == NULL &&
1090 (source->type == OBJT_DEFAULT ||
1091 source->type == OBJT_SWAP))
1092 return;
1093
1094 /*
1095 * Allocate a new object with the given length
1096 */
1097 result = vm_object_allocate(OBJT_DEFAULT, length);
1098 KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing"));
1099
1100 /*
1101 * The new object shadows the source object, adding a reference to it.
1102 * Our caller changes his reference to point to the new object,
1103 * removing a reference to the source object. Net result: no change
1104 * of reference count.
1105 *
1106 * Try to optimize the result object's page color when shadowing
1107 * in order to maintain page coloring consistency in the combined
1108 * shadowed object.
1109 */
1110 result->backing_object = source;
1111 if (source) {
1112 TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list);
1113 source->shadow_count++;
1114 source->generation++;
1115 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1116 }
1117
1118 /*
1119 * Store the offset into the source object, and fix up the offset into
1120 * the new object.
1121 */
1122 result->backing_object_offset = *offset;
1123
1124 /*
1125 * Return the new things
1126 */
1127 *offset = 0;
1128 *object = result;
1129}
1130
1131#define OBSC_TEST_ALL_SHADOWED 0x0001
1132#define OBSC_COLLAPSE_NOWAIT 0x0002
1133#define OBSC_COLLAPSE_WAIT 0x0004
1134
1135static __inline int
1136vm_object_backing_scan(vm_object_t object, int op)
1137{
1138 int s;
1139 int r = 1;
1140 vm_page_t p;
1141 vm_object_t backing_object;
1142 vm_pindex_t backing_offset_index;
1143
1144 s = splvm();
1145 GIANT_REQUIRED;
1146
1147 backing_object = object->backing_object;
1148 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1149
1150 /*
1151 * Initial conditions
1152 */
1153 if (op & OBSC_TEST_ALL_SHADOWED) {
1154 /*
1155 * We do not want to have to test for the existence of
1156 * swap pages in the backing object. XXX but with the
1157 * new swapper this would be pretty easy to do.
1158 *
1159 * XXX what about anonymous MAP_SHARED memory that hasn't
1160 * been ZFOD faulted yet? If we do not test for this, the
1161 * shadow test may succeed! XXX
1162 */
1163 if (backing_object->type != OBJT_DEFAULT) {
1164 splx(s);
1165 return (0);
1166 }
1167 }
1168 if (op & OBSC_COLLAPSE_WAIT) {
1169 vm_object_set_flag(backing_object, OBJ_DEAD);
1170 }
1171
1172 /*
1173 * Our scan
1174 */
1175 p = TAILQ_FIRST(&backing_object->memq);
1176 while (p) {
1177 vm_page_t next = TAILQ_NEXT(p, listq);
1178 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1179
1180 if (op & OBSC_TEST_ALL_SHADOWED) {
1181 vm_page_t pp;
1182
1183 /*
1184 * Ignore pages outside the parent object's range
1185 * and outside the parent object's mapping of the
1186 * backing object.
1187 *
1188 * note that we do not busy the backing object's
1189 * page.
1190 */
1191 if (
1192 p->pindex < backing_offset_index ||
1193 new_pindex >= object->size
1194 ) {
1195 p = next;
1196 continue;
1197 }
1198
1199 /*
1200 * See if the parent has the page or if the parent's
1201 * object pager has the page. If the parent has the
1202 * page but the page is not valid, the parent's
1203 * object pager must have the page.
1204 *
1205 * If this fails, the parent does not completely shadow
1206 * the object and we might as well give up now.
1207 */
1208
1209 pp = vm_page_lookup(object, new_pindex);
1210 if (
1211 (pp == NULL || pp->valid == 0) &&
1212 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1213 ) {
1214 r = 0;
1215 break;
1216 }
1217 }
1218
1219 /*
1220 * Check for busy page
1221 */
1222 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1223 vm_page_t pp;
1224
1225 if (op & OBSC_COLLAPSE_NOWAIT) {
1226 if (
1227 (p->flags & PG_BUSY) ||
1228 !p->valid ||
1229 p->hold_count ||
1230 p->wire_count ||
1231 p->busy
1232 ) {
1233 p = next;
1234 continue;
1235 }
1236 } else if (op & OBSC_COLLAPSE_WAIT) {
1237 if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1238 /*
1239 * If we slept, anything could have
1240 * happened. Since the object is
1241 * marked dead, the backing offset
1242 * should not have changed so we
1243 * just restart our scan.
1244 */
1245 p = TAILQ_FIRST(&backing_object->memq);
1246 continue;
1247 }
1248 }
1249
1250 /*
1251 * Busy the page
1252 */
1253 vm_page_busy(p);
1254
1255 KASSERT(
1256 p->object == backing_object,
1257 ("vm_object_qcollapse(): object mismatch")
1258 );
1259
1260 /*
1261 * Destroy any associated swap
1262 */
1263 if (backing_object->type == OBJT_SWAP) {
1264 swap_pager_freespace(
1265 backing_object,
1266 p->pindex,
1267 1
1268 );
1269 }
1270
1271 if (
1272 p->pindex < backing_offset_index ||
1273 new_pindex >= object->size
1274 ) {
1275 /*
1276 * Page is out of the parent object's range, we
1277 * can simply destroy it.
1278 */
1279 vm_page_protect(p, VM_PROT_NONE);
1280 vm_page_free(p);
1281 p = next;
1282 continue;
1283 }
1284
1285 pp = vm_page_lookup(object, new_pindex);
1286 if (
1287 pp != NULL ||
1288 vm_pager_has_page(object, new_pindex, NULL, NULL)
1289 ) {
1290 /*
1291 * page already exists in parent OR swap exists
1292 * for this location in the parent. Destroy
1293 * the original page from the backing object.
1294 *
1295 * Leave the parent's page alone
1296 */
1297 vm_page_protect(p, VM_PROT_NONE);
1298 vm_page_free(p);
1299 p = next;
1300 continue;
1301 }
1302
1303 /*
1304 * Page does not exist in parent, rename the
1305 * page from the backing object to the main object.
1306 *
1307 * If the page was mapped to a process, it can remain
1308 * mapped through the rename.
1309 */
1310 if ((p->queue - p->pc) == PQ_CACHE)
1311 vm_page_deactivate(p);
1312
1313 vm_page_rename(p, object, new_pindex);
1314 /* page automatically made dirty by rename */
1315 }
1316 p = next;
1317 }
1318 splx(s);
1319 return (r);
1320}
1321
1322
1323/*
1324 * this version of collapse allows the operation to occur earlier and
1325 * when paging_in_progress is true for an object... This is not a complete
1326 * operation, but should plug 99.9% of the rest of the leaks.
1327 */
1328static void
1329vm_object_qcollapse(vm_object_t object)
1330{
1331 vm_object_t backing_object = object->backing_object;
1332
1333 GIANT_REQUIRED;
1334
1335 if (backing_object->ref_count != 1)
1336 return;
1337
1338 backing_object->ref_count += 2;
1339
1340 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1341
1342 backing_object->ref_count -= 2;
1343}
1344
1345/*
1346 * vm_object_collapse:
1347 *
1348 * Collapse an object with the object backing it.
1349 * Pages in the backing object are moved into the
1350 * parent, and the backing object is deallocated.
1351 */
1352void
1353vm_object_collapse(vm_object_t object)
1354{
1355 GIANT_REQUIRED;
1356
1357 while (TRUE) {
1358 vm_object_t backing_object;
1359
1360 /*
1361 * Verify that the conditions are right for collapse:
1362 *
1363 * The object exists and the backing object exists.
1364 */
1365 if (object == NULL)
1366 break;
1367
1368 if ((backing_object = object->backing_object) == NULL)
1369 break;
1370
1371 /*
1372 * we check the backing object first, because it is most likely
1373 * not collapsable.
1374 */
1375 if (backing_object->handle != NULL ||
1376 (backing_object->type != OBJT_DEFAULT &&
1377 backing_object->type != OBJT_SWAP) ||
1378 (backing_object->flags & OBJ_DEAD) ||
1379 object->handle != NULL ||
1380 (object->type != OBJT_DEFAULT &&
1381 object->type != OBJT_SWAP) ||
1382 (object->flags & OBJ_DEAD)) {
1383 break;
1384 }
1385
1386 if (
1387 object->paging_in_progress != 0 ||
1388 backing_object->paging_in_progress != 0
1389 ) {
1390 vm_object_qcollapse(object);
1391 break;
1392 }
1393
1394 /*
1395 * We know that we can either collapse the backing object (if
1396 * the parent is the only reference to it) or (perhaps) have
1397 * the parent bypass the object if the parent happens to shadow
1398 * all the resident pages in the entire backing object.
1399 *
1400 * This is ignoring pager-backed pages such as swap pages.
1401 * vm_object_backing_scan fails the shadowing test in this
1402 * case.
1403 */
1404 if (backing_object->ref_count == 1) {
1405 /*
1406 * If there is exactly one reference to the backing
1407 * object, we can collapse it into the parent.
1408 */
1409 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1410
1411 /*
1412 * Move the pager from backing_object to object.
1413 */
1414 if (backing_object->type == OBJT_SWAP) {
1415 vm_object_pip_add(backing_object, 1);
1416
1417 /*
1418 * scrap the paging_offset junk and do a
1419 * discrete copy. This also removes major
1420 * assumptions about how the swap-pager
1421 * works from where it doesn't belong. The
1422 * new swapper is able to optimize the
1423 * destroy-source case.
1424 */
1425 vm_object_pip_add(object, 1);
1426 swap_pager_copy(
1427 backing_object,
1428 object,
1429 OFF_TO_IDX(object->backing_object_offset), TRUE);
1430 vm_object_pip_wakeup(object);
1431
1432 vm_object_pip_wakeup(backing_object);
1433 }
1434 /*
1435 * Object now shadows whatever backing_object did.
1436 * Note that the reference to
1437 * backing_object->backing_object moves from within
1438 * backing_object to within object.
1439 */
1440 TAILQ_REMOVE(
1441 &object->backing_object->shadow_head,
1442 object,
1443 shadow_list
1444 );
1445 object->backing_object->shadow_count--;
1446 object->backing_object->generation++;
1447 if (backing_object->backing_object) {
1448 TAILQ_REMOVE(
1449 &backing_object->backing_object->shadow_head,
1450 backing_object,
1451 shadow_list
1452 );
1453 backing_object->backing_object->shadow_count--;
1454 backing_object->backing_object->generation++;
1455 }
1456 object->backing_object = backing_object->backing_object;
1457 if (object->backing_object) {
1458 TAILQ_INSERT_TAIL(
1459 &object->backing_object->shadow_head,
1460 object,
1461 shadow_list
1462 );
1463 object->backing_object->shadow_count++;
1464 object->backing_object->generation++;
1465 }
1466
1467 object->backing_object_offset +=
1468 backing_object->backing_object_offset;
1469
1470 /*
1471 * Discard backing_object.
1472 *
1473 * Since the backing object has no pages, no pager left,
1474 * and no object references within it, all that is
1475 * necessary is to dispose of it.
1476 */
1477 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1478 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
1479
1480 TAILQ_REMOVE(
1481 &vm_object_list,
1482 backing_object,
1483 object_list
1484 );
1485
1486 zfree(obj_zone, backing_object);
1487
1488 object_collapses++;
1489 } else {
1490 vm_object_t new_backing_object;
1491
1492 /*
1493 * If we do not entirely shadow the backing object,
1494 * there is nothing we can do so we give up.
1495 */
1496 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1497 break;
1498 }
1499
1500 /*
1501 * Make the parent shadow the next object in the
1502 * chain. Deallocating backing_object will not remove
1503 * it, since its reference count is at least 2.
1504 */
1505 TAILQ_REMOVE(
1506 &backing_object->shadow_head,
1507 object,
1508 shadow_list
1509 );
1510 backing_object->shadow_count--;
1511 backing_object->generation++;
1512
1513 new_backing_object = backing_object->backing_object;
1514 if ((object->backing_object = new_backing_object) != NULL) {
1515 vm_object_reference(new_backing_object);
1516 TAILQ_INSERT_TAIL(
1517 &new_backing_object->shadow_head,
1518 object,
1519 shadow_list
1520 );
1521 new_backing_object->shadow_count++;
1522 new_backing_object->generation++;
1523 object->backing_object_offset +=
1524 backing_object->backing_object_offset;
1525 }
1526
1527 /*
1528 * Drop the reference count on backing_object. Since
1529 * its ref_count was at least 2, it will not vanish;
1530 * so we don't need to call vm_object_deallocate, but
1531 * we do anyway.
1532 */
1533 vm_object_deallocate(backing_object);
1534 object_bypasses++;
1535 }
1536
1537 /*
1538 * Try again with this object's new backing object.
1539 */
1540 }
1541}
1542
1543/*
1544 * vm_object_page_remove: [internal]
1545 *
1546 * Removes all physical pages in the specified
1547 * object range from the object's list of pages.
1548 *
1549 * The object must be locked.
1550 */
1551void
1552vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, boolean_t clean_only)
1553{
1554 vm_page_t p, next;
1555 unsigned int size;
1556 int all;
1557
1558 GIANT_REQUIRED;
1559
1560 if (object == NULL ||
1561 object->resident_page_count == 0)
1562 return;
1563
1564 all = ((end == 0) && (start == 0));
1565
1566 /*
1567 * Since physically-backed objects do not use managed pages, we can't
1568 * remove pages from the object (we must instead remove the page
1569 * references, and then destroy the object).
1570 */
1571 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object"));
1572
1573 vm_object_pip_add(object, 1);
1574again:
1575 size = end - start;
1576 if (all || size > object->resident_page_count / 4) {
1577 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
1578 next = TAILQ_NEXT(p, listq);
1579 if (all || ((start <= p->pindex) && (p->pindex < end))) {
1580 if (p->wire_count != 0) {
1581 vm_page_protect(p, VM_PROT_NONE);
1582 if (!clean_only)
1583 p->valid = 0;
1584 continue;
1585 }
1586
1587 /*
1588 * The busy flags are only cleared at
1589 * interrupt -- minimize the spl transitions
1590 */
1591 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1592 goto again;
1593
1594 if (clean_only && p->valid) {
1595 vm_page_test_dirty(p);
1596 if (p->valid & p->dirty)
1597 continue;
1598 }
1599
1600 vm_page_busy(p);
1601 vm_page_protect(p, VM_PROT_NONE);
1602 vm_page_free(p);
1603 }
1604 }
1605 } else {
1606 while (size > 0) {
1607 if ((p = vm_page_lookup(object, start)) != 0) {
1608
1609 if (p->wire_count != 0) {
1610 vm_page_protect(p, VM_PROT_NONE);
1611 if (!clean_only)
1612 p->valid = 0;
1613 start += 1;
1614 size -= 1;
1615 continue;
1616 }
1617
1618 /*
1619 * The busy flags are only cleared at
1620 * interrupt -- minimize the spl transitions
1621 */
1622 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1623 goto again;
1624
1625 if (clean_only && p->valid) {
1626 vm_page_test_dirty(p);
1627 if (p->valid & p->dirty) {
1628 start += 1;
1629 size -= 1;
1630 continue;
1631 }
1632 }
1633
1634 vm_page_busy(p);
1635 vm_page_protect(p, VM_PROT_NONE);
1636 vm_page_free(p);
1637 }
1638 start += 1;
1639 size -= 1;
1640 }
1641 }
1642 vm_object_pip_wakeup(object);
1643}
1644
1645/*
1646 * Routine: vm_object_coalesce
1647 * Function: Coalesces two objects backing up adjoining
1648 * regions of memory into a single object.
1649 *
1650 * returns TRUE if objects were combined.
1651 *
1652 * NOTE: Only works at the moment if the second object is NULL -
1653 * if it's not, which object do we lock first?
1654 *
1655 * Parameters:
1656 * prev_object First object to coalesce
1657 * prev_offset Offset into prev_object
1658 * next_object Second object into coalesce
1659 * next_offset Offset into next_object
1660 *
1661 * prev_size Size of reference to prev_object
1662 * next_size Size of reference to next_object
1663 *
1664 * Conditions:
1665 * The object must *not* be locked.
1666 */
1667boolean_t
1668vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size)
1669{
1670 vm_pindex_t next_pindex;
1671
1672 GIANT_REQUIRED;
1673
1674 if (prev_object == NULL) {
1675 return (TRUE);
1676 }
1677
1678 if (prev_object->type != OBJT_DEFAULT &&
1679 prev_object->type != OBJT_SWAP) {
1680 return (FALSE);
1681 }
1682
1683 /*
1684 * Try to collapse the object first
1685 */
1686 vm_object_collapse(prev_object);
1687
1688 /*
1689 * Can't coalesce if: . more than one reference . paged out . shadows
1690 * another object . has a copy elsewhere (any of which mean that the
1691 * pages not mapped to prev_entry may be in use anyway)
1692 */
1693 if (prev_object->backing_object != NULL) {
1694 return (FALSE);
1695 }
1696
1697 prev_size >>= PAGE_SHIFT;
1698 next_size >>= PAGE_SHIFT;
1699 next_pindex = prev_pindex + prev_size;
1700
1701 if ((prev_object->ref_count > 1) &&
1702 (prev_object->size != next_pindex)) {
1703 return (FALSE);
1704 }
1705
1706 /*
1707 * Remove any pages that may still be in the object from a previous
1708 * deallocation.
1709 */
1710 if (next_pindex < prev_object->size) {
1711 vm_object_page_remove(prev_object,
1712 next_pindex,
1713 next_pindex + next_size, FALSE);
1714 if (prev_object->type == OBJT_SWAP)
1715 swap_pager_freespace(prev_object,
1716 next_pindex, next_size);
1717 }
1718
1719 /*
1720 * Extend the object if necessary.
1721 */
1722 if (next_pindex + next_size > prev_object->size)
1723 prev_object->size = next_pindex + next_size;
1724
1725 return (TRUE);
1726}
1727
1728void
1729vm_object_set_writeable_dirty(vm_object_t object)
1730{
1731 struct vnode *vp;
1732
1733 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1734 if (object->type == OBJT_VNODE &&
1735 (vp = (struct vnode *)object->handle) != NULL) {
1736 if ((vp->v_flag & VOBJDIRTY) == 0) {
1737 mtx_lock(&vp->v_interlock);
1738 vp->v_flag |= VOBJDIRTY;
1739 mtx_unlock(&vp->v_interlock);
1740 }
1741 }
1742}
1743
1744#include "opt_ddb.h"
1745#ifdef DDB
1746#include <sys/kernel.h>
1747
1748#include <sys/cons.h>
1749
1750#include <ddb/ddb.h>
1751
1752static int
1753_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1754{
1755 vm_map_t tmpm;
1756 vm_map_entry_t tmpe;
1757 vm_object_t obj;
1758 int entcount;
1759
1760 if (map == 0)
1761 return 0;
1762
1763 if (entry == 0) {
1764 tmpe = map->header.next;
1765 entcount = map->nentries;
1766 while (entcount-- && (tmpe != &map->header)) {
1767 if (_vm_object_in_map(map, object, tmpe)) {
1768 return 1;
1769 }
1770 tmpe = tmpe->next;
1771 }
1772 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1773 tmpm = entry->object.sub_map;
1774 tmpe = tmpm->header.next;
1775 entcount = tmpm->nentries;
1776 while (entcount-- && tmpe != &tmpm->header) {
1777 if (_vm_object_in_map(tmpm, object, tmpe)) {
1778 return 1;
1779 }
1780 tmpe = tmpe->next;
1781 }
1782 } else if ((obj = entry->object.vm_object) != NULL) {
1783 for (; obj; obj = obj->backing_object)
1784 if (obj == object) {
1785 return 1;
1786 }
1787 }
1788 return 0;
1789}
1790
1791static int
1792vm_object_in_map(vm_object_t object)
1793{
1794 struct proc *p;
1795
1796 /* sx_slock(&allproc_lock); */
1797 LIST_FOREACH(p, &allproc, p_list) {
1798 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1799 continue;
1800 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1801 /* sx_sunlock(&allproc_lock); */
1802 return 1;
1803 }
1804 }
1805 /* sx_sunlock(&allproc_lock); */
1806 if (_vm_object_in_map(kernel_map, object, 0))
1807 return 1;
1808 if (_vm_object_in_map(kmem_map, object, 0))
1809 return 1;
1810 if (_vm_object_in_map(pager_map, object, 0))
1811 return 1;
1812 if (_vm_object_in_map(buffer_map, object, 0))
1813 return 1;
1814 return 0;
1815}
1816
1817DB_SHOW_COMMAND(vmochk, vm_object_check)
1818{
1819 vm_object_t object;
1820
1821 /*
1822 * make sure that internal objs are in a map somewhere
1823 * and none have zero ref counts.
1824 */
1825 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1826 if (object->handle == NULL &&
1827 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
1828 if (object->ref_count == 0) {
1829 db_printf("vmochk: internal obj has zero ref count: %ld\n",
1830 (long)object->size);
1831 }
1832 if (!vm_object_in_map(object)) {
1833 db_printf(
1834 "vmochk: internal obj is not in a map: "
1835 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
1836 object->ref_count, (u_long)object->size,
1837 (u_long)object->size,
1838 (void *)object->backing_object);
1839 }
1840 }
1841 }
1842}
1843
1844/*
1845 * vm_object_print: [ debug ]
1846 */
1847DB_SHOW_COMMAND(object, vm_object_print_static)
1848{
1849 /* XXX convert args. */
1850 vm_object_t object = (vm_object_t)addr;
1851 boolean_t full = have_addr;
1852
1853 vm_page_t p;
1854
1855 /* XXX count is an (unused) arg. Avoid shadowing it. */
1856#define count was_count
1857
1858 int count;
1859
1860 if (object == NULL)
1861 return;
1862
1863 db_iprintf(
1864 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
1865 object, (int)object->type, (u_long)object->size,
1866 object->resident_page_count, object->ref_count, object->flags);
1867 /*
1868 * XXX no %qd in kernel. Truncate object->backing_object_offset.
1869 */
1870 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
1871 object->shadow_count,
1872 object->backing_object ? object->backing_object->ref_count : 0,
1873 object->backing_object, (long)object->backing_object_offset);
1874
1875 if (!full)
1876 return;
1877
1878 db_indent += 2;
1879 count = 0;
1880 TAILQ_FOREACH(p, &object->memq, listq) {
1881 if (count == 0)
1882 db_iprintf("memory:=");
1883 else if (count == 6) {
1884 db_printf("\n");
1885 db_iprintf(" ...");
1886 count = 0;
1887 } else
1888 db_printf(",");
1889 count++;
1890
1891 db_printf("(off=0x%lx,page=0x%lx)",
1892 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
1893 }
1894 if (count != 0)
1895 db_printf("\n");
1896 db_indent -= 2;
1897}
1898
1899/* XXX. */
1900#undef count
1901
1902/* XXX need this non-static entry for calling from vm_map_print. */
1903void
1904vm_object_print(
1905 /* db_expr_t */ long addr,
1906 boolean_t have_addr,
1907 /* db_expr_t */ long count,
1908 char *modif)
1909{
1910 vm_object_print_static(addr, have_addr, count, modif);
1911}
1912
1913DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
1914{
1915 vm_object_t object;
1916 int nl = 0;
1917 int c;
1918
1919 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1920 vm_pindex_t idx, fidx;
1921 vm_pindex_t osize;
1922 vm_offset_t pa = -1, padiff;
1923 int rcount;
1924 vm_page_t m;
1925
1926 db_printf("new object: %p\n", (void *)object);
1927 if (nl > 18) {
1928 c = cngetc();
1929 if (c != ' ')
1930 return;
1931 nl = 0;
1932 }
1933 nl++;
1934 rcount = 0;
1935 fidx = 0;
1936 osize = object->size;
1937 if (osize > 128)
1938 osize = 128;
1939 for (idx = 0; idx < osize; idx++) {
1940 m = vm_page_lookup(object, idx);
1941 if (m == NULL) {
1942 if (rcount) {
1943 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1944 (long)fidx, rcount, (long)pa);
1945 if (nl > 18) {
1946 c = cngetc();
1947 if (c != ' ')
1948 return;
1949 nl = 0;
1950 }
1951 nl++;
1952 rcount = 0;
1953 }
1954 continue;
1955 }
1956
1957
1958 if (rcount &&
1959 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
1960 ++rcount;
1961 continue;
1962 }
1963 if (rcount) {
1964 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
1965 padiff >>= PAGE_SHIFT;
1966 padiff &= PQ_L2_MASK;
1967 if (padiff == 0) {
1968 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
1969 ++rcount;
1970 continue;
1971 }
1972 db_printf(" index(%ld)run(%d)pa(0x%lx)",
1973 (long)fidx, rcount, (long)pa);
1974 db_printf("pd(%ld)\n", (long)padiff);
1975 if (nl > 18) {
1976 c = cngetc();
1977 if (c != ' ')
1978 return;
1979 nl = 0;
1980 }
1981 nl++;
1982 }
1983 fidx = idx;
1984 pa = VM_PAGE_TO_PHYS(m);
1985 rcount = 1;
1986 }
1987 if (rcount) {
1988 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1989 (long)fidx, rcount, (long)pa);
1990 if (nl > 18) {
1991 c = cngetc();
1992 if (c != ' ')
1993 return;
1994 nl = 0;
1995 }
1996 nl++;
1997 }
1998 }
1999}
2000#endif /* DDB */