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 92654 2002-03-19 09:11:49Z jeff $
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 int object_hash_rand;
151static vm_zone_t obj_zone;
152#define VM_OBJECTS_INIT 256
153
154static void vm_object_zinit(void *mem, int size);
155
156#ifdef INVARIANTS
157static void vm_object_zdtor(void *mem, int size, void *arg);
158
159static void
160vm_object_zdtor(void *mem, int size, void *arg)
161{
162 vm_object_t object;
163
164 object = (vm_object_t)mem;
165 KASSERT(object->paging_in_progress == 0,
166 ("object %p paging_in_progress = %d",
167 object, object->paging_in_progress));
168 KASSERT(object->resident_page_count == 0,
169 ("object %p resident_page_count = %d",
170 object, object->resident_page_count));
171 KASSERT(object->shadow_count == 0,
172 ("object %p shadow_count = %d",
173 object, object->shadow_count));
174}
175#endif
176
177static void
178vm_object_zinit(void *mem, int size)
179{
180 vm_object_t object;
181
182 object = (vm_object_t)mem;
183
184 /* These are true for any object that has been freed */
185 object->paging_in_progress = 0;
186 object->resident_page_count = 0;
187 object->shadow_count = 0;
188}
189
190void
191_vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object)
192{
193 int incr;
194
195 GIANT_REQUIRED;
196
197 TAILQ_INIT(&object->memq);
198 TAILQ_INIT(&object->shadow_head);
199
200 object->type = type;
201 object->size = size;
202 object->ref_count = 1;
203 object->flags = 0;
204 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
205 vm_object_set_flag(object, OBJ_ONEMAPPING);
206 object->pg_color = next_index;
207 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
208 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
209 else
210 incr = size;
211 next_index = (next_index + incr) & PQ_L2_MASK;
212 object->handle = NULL;
213 object->backing_object = NULL;
214 object->backing_object_offset = (vm_ooffset_t) 0;
215 /*
216 * Try to generate a number that will spread objects out in the
217 * hash table. We 'wipe' new objects across the hash in 128 page
218 * increments plus 1 more to offset it a little more by the time
219 * it wraps around.
220 */
221 object->hash_rand = object_hash_rand - 129;
222
223 object->generation++;
224
225 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
226
227 object_hash_rand = object->hash_rand;
228}
229
230/*
231 * vm_object_init:
232 *
233 * Initialize the VM objects module.
234 */
235void
236vm_object_init(void)
237{
238 GIANT_REQUIRED;
239
240 TAILQ_INIT(&vm_object_list);
241 mtx_init(&vm_object_list_mtx, "vm object_list", MTX_DEF);
242
243 kernel_object = &kernel_object_store;
244 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
245 kernel_object);
246
247 kmem_object = &kmem_object_store;
248 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
249 kmem_object);
250 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
251#ifdef INVARIANTS
252 vm_object_zdtor,
253#else
254 NULL,
255#endif
256 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
257 uma_prealloc(obj_zone, VM_OBJECTS_INIT);
258}
259
260void
261vm_object_init2(void)
262{
263}
264
265void
266vm_object_set_flag(vm_object_t object, u_short bits)
267{
268 GIANT_REQUIRED;
269 object->flags |= bits;
270}
271
272void
273vm_object_clear_flag(vm_object_t object, u_short bits)
274{
275 GIANT_REQUIRED;
276 object->flags &= ~bits;
277}
278
279void
280vm_object_pip_add(vm_object_t object, short i)
281{
282 GIANT_REQUIRED;
283 object->paging_in_progress += i;
284}
285
286void
287vm_object_pip_subtract(vm_object_t object, short i)
288{
289 GIANT_REQUIRED;
290 object->paging_in_progress -= i;
291}
292
293void
294vm_object_pip_wakeup(vm_object_t object)
295{
296 GIANT_REQUIRED;
297 object->paging_in_progress--;
298 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
299 vm_object_clear_flag(object, OBJ_PIPWNT);
300 wakeup(object);
301 }
302}
303
304void
305vm_object_pip_wakeupn(vm_object_t object, short i)
306{
307 GIANT_REQUIRED;
308 if (i)
309 object->paging_in_progress -= i;
310 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
311 vm_object_clear_flag(object, OBJ_PIPWNT);
312 wakeup(object);
313 }
314}
315
316void
317vm_object_pip_sleep(vm_object_t object, char *waitid)
318{
319 GIANT_REQUIRED;
320 if (object->paging_in_progress) {
321 int s = splvm();
322 if (object->paging_in_progress) {
323 vm_object_set_flag(object, OBJ_PIPWNT);
324 tsleep(object, PVM, waitid, 0);
325 }
326 splx(s);
327 }
328}
329
330void
331vm_object_pip_wait(vm_object_t object, char *waitid)
332{
333 GIANT_REQUIRED;
334 while (object->paging_in_progress)
335 vm_object_pip_sleep(object, waitid);
336}
337
338/*
339 * vm_object_allocate:
340 *
341 * Returns a new object with the given size.
342 */
343vm_object_t
344vm_object_allocate(objtype_t type, vm_size_t size)
345{
346 vm_object_t result;
347
348 GIANT_REQUIRED;
349
350 result = (vm_object_t) zalloc(obj_zone);
351 _vm_object_allocate(type, size, result);
352
353 return (result);
354}
355
356
357/*
358 * vm_object_reference:
359 *
360 * Gets another reference to the given object.
361 */
362void
363vm_object_reference(vm_object_t object)
364{
365 GIANT_REQUIRED;
366
367 if (object == NULL)
368 return;
369
370#if 0
371 /* object can be re-referenced during final cleaning */
372 KASSERT(!(object->flags & OBJ_DEAD),
373 ("vm_object_reference: attempting to reference dead obj"));
374#endif
375
376 object->ref_count++;
377 if (object->type == OBJT_VNODE) {
378 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) {
379 printf("vm_object_reference: delay in getting object\n");
380 }
381 }
382}
383
384/*
385 * handle deallocating a object of type OBJT_VNODE
386 */
387void
388vm_object_vndeallocate(vm_object_t object)
389{
390 struct vnode *vp = (struct vnode *) object->handle;
391
392 GIANT_REQUIRED;
393 KASSERT(object->type == OBJT_VNODE,
394 ("vm_object_vndeallocate: not a vnode object"));
395 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
396#ifdef INVARIANTS
397 if (object->ref_count == 0) {
398 vprint("vm_object_vndeallocate", vp);
399 panic("vm_object_vndeallocate: bad object reference count");
400 }
401#endif
402
403 object->ref_count--;
404 if (object->ref_count == 0) {
405 vp->v_flag &= ~VTEXT;
406 vm_object_clear_flag(object, OBJ_OPT);
407 }
408 /*
409 * vrele may need a vop lock
410 */
411 vrele(vp);
412}
413
414/*
415 * vm_object_deallocate:
416 *
417 * Release a reference to the specified object,
418 * gained either through a vm_object_allocate
419 * or a vm_object_reference call. When all references
420 * are gone, storage associated with this object
421 * may be relinquished.
422 *
423 * No object may be locked.
424 */
425void
426vm_object_deallocate(vm_object_t object)
427{
428 vm_object_t temp;
429
430 GIANT_REQUIRED;
431
432 while (object != NULL) {
433
434 if (object->type == OBJT_VNODE) {
435 vm_object_vndeallocate(object);
436 return;
437 }
438
439 KASSERT(object->ref_count != 0,
440 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
441
442 /*
443 * If the reference count goes to 0 we start calling
444 * vm_object_terminate() on the object chain.
445 * A ref count of 1 may be a special case depending on the
446 * shadow count being 0 or 1.
447 */
448 object->ref_count--;
449 if (object->ref_count > 1) {
450 return;
451 } else if (object->ref_count == 1) {
452 if (object->shadow_count == 0) {
453 vm_object_set_flag(object, OBJ_ONEMAPPING);
454 } else if ((object->shadow_count == 1) &&
455 (object->handle == NULL) &&
456 (object->type == OBJT_DEFAULT ||
457 object->type == OBJT_SWAP)) {
458 vm_object_t robject;
459
460 robject = TAILQ_FIRST(&object->shadow_head);
461 KASSERT(robject != NULL,
462 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
463 object->ref_count,
464 object->shadow_count));
465 if ((robject->handle == NULL) &&
466 (robject->type == OBJT_DEFAULT ||
467 robject->type == OBJT_SWAP)) {
468
469 robject->ref_count++;
470
471 while (
472 robject->paging_in_progress ||
473 object->paging_in_progress
474 ) {
475 vm_object_pip_sleep(robject, "objde1");
476 vm_object_pip_sleep(object, "objde2");
477 }
478
479 if (robject->ref_count == 1) {
480 robject->ref_count--;
481 object = robject;
482 goto doterm;
483 }
484
485 object = robject;
486 vm_object_collapse(object);
487 continue;
488 }
489 }
490
491 return;
492
493 }
494
495doterm:
496
497 temp = object->backing_object;
498 if (temp) {
499 TAILQ_REMOVE(&temp->shadow_head, object, shadow_list);
500 temp->shadow_count--;
501 if (temp->ref_count == 0)
502 vm_object_clear_flag(temp, OBJ_OPT);
503 temp->generation++;
504 object->backing_object = NULL;
505 }
506 /*
507 * Don't double-terminate, we could be in a termination
508 * recursion due to the terminate having to sync data
509 * to disk.
510 */
511 if ((object->flags & OBJ_DEAD) == 0)
512 vm_object_terminate(object);
513 object = temp;
514 }
515}
516
517/*
518 * vm_object_terminate actually destroys the specified object, freeing
519 * up all previously used resources.
520 *
521 * The object must be locked.
522 * This routine may block.
523 */
524void
525vm_object_terminate(vm_object_t object)
526{
527 vm_page_t p;
528 int s;
529
530 GIANT_REQUIRED;
531
532 /*
533 * Make sure no one uses us.
534 */
535 vm_object_set_flag(object, OBJ_DEAD);
536
537 /*
538 * wait for the pageout daemon to be done with the object
539 */
540 vm_object_pip_wait(object, "objtrm");
541
542 KASSERT(!object->paging_in_progress,
543 ("vm_object_terminate: pageout in progress"));
544
545 /*
546 * Clean and free the pages, as appropriate. All references to the
547 * object are gone, so we don't need to lock it.
548 */
549 if (object->type == OBJT_VNODE) {
550 struct vnode *vp;
551
552 /*
553 * Freeze optimized copies.
554 */
555 vm_freeze_copyopts(object, 0, object->size);
556
557 /*
558 * Clean pages and flush buffers.
559 */
560 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
561
562 vp = (struct vnode *) object->handle;
563 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
564 }
565
566 KASSERT(object->ref_count == 0,
567 ("vm_object_terminate: object with references, ref_count=%d",
568 object->ref_count));
569
570 /*
571 * Now free any remaining pages. For internal objects, this also
572 * removes them from paging queues. Don't free wired pages, just
573 * remove them from the object.
574 */
575 s = splvm();
576 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
577 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
578 ("vm_object_terminate: freeing busy page %p "
579 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
580 if (p->wire_count == 0) {
581 vm_page_busy(p);
582 vm_page_free(p);
583 cnt.v_pfree++;
584 } else {
585 vm_page_busy(p);
586 vm_page_remove(p);
587 }
588 }
589 splx(s);
590
591 /*
592 * Let the pager know object is dead.
593 */
594 vm_pager_deallocate(object);
595
596 /*
597 * Remove the object from the global object list.
598 */
599 mtx_lock(&vm_object_list_mtx);
600 TAILQ_REMOVE(&vm_object_list, object, object_list);
601 mtx_unlock(&vm_object_list_mtx);
602
603 wakeup(object);
604
605 /*
606 * Free the space for the object.
607 */
608 zfree(obj_zone, object);
609}
610
611/*
612 * vm_object_page_clean
613 *
614 * Clean all dirty pages in the specified range of object. Leaves page
615 * on whatever queue it is currently on. If NOSYNC is set then do not
616 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
617 * leaving the object dirty.
618 *
619 * Odd semantics: if start == end, we clean everything.
620 *
621 * The object must be locked.
622 */
623void
624vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
625{
626 vm_page_t p, np;
627 vm_offset_t tstart, tend;
628 vm_pindex_t pi;
629 struct vnode *vp;
630 int clearobjflags;
631 int pagerflags;
632 int curgeneration;
633
634 GIANT_REQUIRED;
635
636 if (object->type != OBJT_VNODE ||
637 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
638 return;
639
640 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : 0;
641 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
642
643 vp = object->handle;
644
645 vm_object_set_flag(object, OBJ_CLEANING);
646
647 tstart = start;
648 if (end == 0) {
649 tend = object->size;
650 } else {
651 tend = end;
652 }
653
654 /*
655 * If the caller is smart and only msync()s a range he knows is
656 * dirty, we may be able to avoid an object scan. This results in
657 * a phenominal improvement in performance. We cannot do this
658 * as a matter of course because the object may be huge - e.g.
659 * the size might be in the gigabytes or terrabytes.
660 */
661 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
662 vm_offset_t tscan;
663 int scanlimit;
664 int scanreset;
665
666 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
667 if (scanreset < 16)
668 scanreset = 16;
669
670 scanlimit = scanreset;
671 tscan = tstart;
672 while (tscan < tend) {
673 curgeneration = object->generation;
674 p = vm_page_lookup(object, tscan);
675 if (p == NULL || p->valid == 0 ||
676 (p->queue - p->pc) == PQ_CACHE) {
677 if (--scanlimit == 0)
678 break;
679 ++tscan;
680 continue;
681 }
682 vm_page_test_dirty(p);
683 if ((p->dirty & p->valid) == 0) {
684 if (--scanlimit == 0)
685 break;
686 ++tscan;
687 continue;
688 }
689 /*
690 * If we have been asked to skip nosync pages and
691 * this is a nosync page, we can't continue.
692 */
693 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
694 if (--scanlimit == 0)
695 break;
696 ++tscan;
697 continue;
698 }
699 scanlimit = scanreset;
700
701 /*
702 * This returns 0 if it was unable to busy the first
703 * page (i.e. had to sleep).
704 */
705 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
706 }
707
708 /*
709 * If everything was dirty and we flushed it successfully,
710 * and the requested range is not the entire object, we
711 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
712 * return immediately.
713 */
714 if (tscan >= tend && (tstart || tend < object->size)) {
715 vm_object_clear_flag(object, OBJ_CLEANING);
716 return;
717 }
718 }
719
720 /*
721 * Generally set CLEANCHK interlock and make the page read-only so
722 * we can then clear the object flags.
723 *
724 * However, if this is a nosync mmap then the object is likely to
725 * stay dirty so do not mess with the page and do not clear the
726 * object flags.
727 */
728 clearobjflags = 1;
729
730 TAILQ_FOREACH(p, &object->memq, listq) {
731 vm_page_flag_set(p, PG_CLEANCHK);
732 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
733 clearobjflags = 0;
734 else
735 vm_page_protect(p, VM_PROT_READ);
736 }
737
738 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
739 struct vnode *vp;
740
741 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
742 if (object->type == OBJT_VNODE &&
743 (vp = (struct vnode *)object->handle) != NULL) {
744 if (vp->v_flag & VOBJDIRTY) {
745 mtx_lock(&vp->v_interlock);
746 vp->v_flag &= ~VOBJDIRTY;
747 mtx_unlock(&vp->v_interlock);
748 }
749 }
750 }
751
752rescan:
753 curgeneration = object->generation;
754
755 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
756 int n;
757
758 np = TAILQ_NEXT(p, listq);
759
760again:
761 pi = p->pindex;
762 if (((p->flags & PG_CLEANCHK) == 0) ||
763 (pi < tstart) || (pi >= tend) ||
764 (p->valid == 0) ||
765 ((p->queue - p->pc) == PQ_CACHE)) {
766 vm_page_flag_clear(p, PG_CLEANCHK);
767 continue;
768 }
769
770 vm_page_test_dirty(p);
771 if ((p->dirty & p->valid) == 0) {
772 vm_page_flag_clear(p, PG_CLEANCHK);
773 continue;
774 }
775
776 /*
777 * If we have been asked to skip nosync pages and this is a
778 * nosync page, skip it. Note that the object flags were
779 * not cleared in this case so we do not have to set them.
780 */
781 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
782 vm_page_flag_clear(p, PG_CLEANCHK);
783 continue;
784 }
785
786 n = vm_object_page_collect_flush(object, p,
787 curgeneration, pagerflags);
788 if (n == 0)
789 goto rescan;
790
791 if (object->generation != curgeneration)
792 goto rescan;
793
794 /*
795 * Try to optimize the next page. If we can't we pick up
796 * our (random) scan where we left off.
797 */
798 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
799 if ((p = vm_page_lookup(object, pi + n)) != NULL)
800 goto again;
801 }
802 }
803
804#if 0
805 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
806#endif
807
808 vm_object_clear_flag(object, OBJ_CLEANING);
809 return;
810}
811
812static int
813vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
814{
815 int runlen;
816 int s;
817 int maxf;
818 int chkb;
819 int maxb;
820 int i;
821 vm_pindex_t pi;
822 vm_page_t maf[vm_pageout_page_count];
823 vm_page_t mab[vm_pageout_page_count];
824 vm_page_t ma[vm_pageout_page_count];
825
826 s = splvm();
827 pi = p->pindex;
828 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
829 if (object->generation != curgeneration) {
830 splx(s);
831 return(0);
832 }
833 }
834
835 maxf = 0;
836 for(i = 1; i < vm_pageout_page_count; i++) {
837 vm_page_t tp;
838
839 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
840 if ((tp->flags & PG_BUSY) ||
841 (tp->flags & PG_CLEANCHK) == 0 ||
842 (tp->busy != 0))
843 break;
844 if((tp->queue - tp->pc) == PQ_CACHE) {
845 vm_page_flag_clear(tp, PG_CLEANCHK);
846 break;
847 }
848 vm_page_test_dirty(tp);
849 if ((tp->dirty & tp->valid) == 0) {
850 vm_page_flag_clear(tp, PG_CLEANCHK);
851 break;
852 }
853 maf[ i - 1 ] = tp;
854 maxf++;
855 continue;
856 }
857 break;
858 }
859
860 maxb = 0;
861 chkb = vm_pageout_page_count - maxf;
862 if (chkb) {
863 for(i = 1; i < chkb;i++) {
864 vm_page_t tp;
865
866 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
867 if ((tp->flags & PG_BUSY) ||
868 (tp->flags & PG_CLEANCHK) == 0 ||
869 (tp->busy != 0))
870 break;
871 if ((tp->queue - tp->pc) == PQ_CACHE) {
872 vm_page_flag_clear(tp, PG_CLEANCHK);
873 break;
874 }
875 vm_page_test_dirty(tp);
876 if ((tp->dirty & tp->valid) == 0) {
877 vm_page_flag_clear(tp, PG_CLEANCHK);
878 break;
879 }
880 mab[ i - 1 ] = tp;
881 maxb++;
882 continue;
883 }
884 break;
885 }
886 }
887
888 for(i = 0; i < maxb; i++) {
889 int index = (maxb - i) - 1;
890 ma[index] = mab[i];
891 vm_page_flag_clear(ma[index], PG_CLEANCHK);
892 }
893 vm_page_flag_clear(p, PG_CLEANCHK);
894 ma[maxb] = p;
895 for(i = 0; i < maxf; i++) {
896 int index = (maxb + i) + 1;
897 ma[index] = maf[i];
898 vm_page_flag_clear(ma[index], PG_CLEANCHK);
899 }
900 runlen = maxb + maxf + 1;
901
902 splx(s);
903 vm_pageout_flush(ma, runlen, pagerflags);
904 for (i = 0; i < runlen; i++) {
905 if (ma[i]->valid & ma[i]->dirty) {
906 vm_page_protect(ma[i], VM_PROT_READ);
907 vm_page_flag_set(ma[i], PG_CLEANCHK);
908
909 /*
910 * maxf will end up being the actual number of pages
911 * we wrote out contiguously, non-inclusive of the
912 * first page. We do not count look-behind pages.
913 */
914 if (i >= maxb + 1 && (maxf > i - maxb - 1))
915 maxf = i - maxb - 1;
916 }
917 }
918 return(maxf + 1);
919}
920
921/*
922 * Same as vm_object_pmap_copy, except range checking really
923 * works, and is meant for small sections of an object.
924 *
925 * This code protects resident pages by making them read-only
926 * and is typically called on a fork or split when a page
927 * is converted to copy-on-write.
928 *
929 * NOTE: If the page is already at VM_PROT_NONE, calling
930 * vm_page_protect will have no effect.
931 */
932void
933vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
934{
935 vm_pindex_t idx;
936 vm_page_t p;
937
938 GIANT_REQUIRED;
939
940 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
941 return;
942
943 for (idx = start; idx < end; idx++) {
944 p = vm_page_lookup(object, idx);
945 if (p == NULL)
946 continue;
947 vm_page_protect(p, VM_PROT_READ);
948 }
949}
950
951/*
952 * vm_object_pmap_remove:
953 *
954 * Removes all physical pages in the specified
955 * object range from all physical maps.
956 *
957 * The object must *not* be locked.
958 */
959void
960vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
961{
962 vm_page_t p;
963
964 GIANT_REQUIRED;
965 if (object == NULL)
966 return;
967 TAILQ_FOREACH(p, &object->memq, listq) {
968 if (p->pindex >= start && p->pindex < end)
969 vm_page_protect(p, VM_PROT_NONE);
970 }
971 if ((start == 0) && (object->size == end))
972 vm_object_clear_flag(object, OBJ_WRITEABLE);
973}
974
975/*
976 * vm_object_madvise:
977 *
978 * Implements the madvise function at the object/page level.
979 *
980 * MADV_WILLNEED (any object)
981 *
982 * Activate the specified pages if they are resident.
983 *
984 * MADV_DONTNEED (any object)
985 *
986 * Deactivate the specified pages if they are resident.
987 *
988 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
989 * OBJ_ONEMAPPING only)
990 *
991 * Deactivate and clean the specified pages if they are
992 * resident. This permits the process to reuse the pages
993 * without faulting or the kernel to reclaim the pages
994 * without I/O.
995 */
996void
997vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
998{
999 vm_pindex_t end, tpindex;
1000 vm_object_t tobject;
1001 vm_page_t m;
1002
1003 GIANT_REQUIRED;
1004 if (object == NULL)
1005 return;
1006
1007 end = pindex + count;
1008
1009 /*
1010 * Locate and adjust resident pages
1011 */
1012 for (; pindex < end; pindex += 1) {
1013relookup:
1014 tobject = object;
1015 tpindex = pindex;
1016shadowlookup:
1017 /*
1018 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1019 * and those pages must be OBJ_ONEMAPPING.
1020 */
1021 if (advise == MADV_FREE) {
1022 if ((tobject->type != OBJT_DEFAULT &&
1023 tobject->type != OBJT_SWAP) ||
1024 (tobject->flags & OBJ_ONEMAPPING) == 0) {
1025 continue;
1026 }
1027 }
1028
1029 m = vm_page_lookup(tobject, tpindex);
1030
1031 if (m == NULL) {
1032 /*
1033 * There may be swap even if there is no backing page
1034 */
1035 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1036 swap_pager_freespace(tobject, tpindex, 1);
1037
1038 /*
1039 * next object
1040 */
1041 tobject = tobject->backing_object;
1042 if (tobject == NULL)
1043 continue;
1044 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1045 goto shadowlookup;
1046 }
1047
1048 /*
1049 * If the page is busy or not in a normal active state,
1050 * we skip it. If the page is not managed there are no
1051 * page queues to mess with. Things can break if we mess
1052 * with pages in any of the below states.
1053 */
1054 if (
1055 m->hold_count ||
1056 m->wire_count ||
1057 (m->flags & PG_UNMANAGED) ||
1058 m->valid != VM_PAGE_BITS_ALL
1059 ) {
1060 continue;
1061 }
1062
1063 if (vm_page_sleep_busy(m, TRUE, "madvpo"))
1064 goto relookup;
1065
1066 if (advise == MADV_WILLNEED) {
1067 vm_page_activate(m);
1068 } else if (advise == MADV_DONTNEED) {
1069 vm_page_dontneed(m);
1070 } else if (advise == MADV_FREE) {
1071 /*
1072 * Mark the page clean. This will allow the page
1073 * to be freed up by the system. However, such pages
1074 * are often reused quickly by malloc()/free()
1075 * so we do not do anything that would cause
1076 * a page fault if we can help it.
1077 *
1078 * Specifically, we do not try to actually free
1079 * the page now nor do we try to put it in the
1080 * cache (which would cause a page fault on reuse).
1081 *
1082 * But we do make the page is freeable as we
1083 * can without actually taking the step of unmapping
1084 * it.
1085 */
1086 pmap_clear_modify(m);
1087 m->dirty = 0;
1088 m->act_count = 0;
1089 vm_page_dontneed(m);
1090 if (tobject->type == OBJT_SWAP)
1091 swap_pager_freespace(tobject, tpindex, 1);
1092 }
1093 }
1094}
1095
1096/*
1097 * vm_object_shadow:
1098 *
1099 * Create a new object which is backed by the
1100 * specified existing object range. The source
1101 * object reference is deallocated.
1102 *
1103 * The new object and offset into that object
1104 * are returned in the source parameters.
1105 */
1106void
1107vm_object_shadow(
1108 vm_object_t *object, /* IN/OUT */
1109 vm_ooffset_t *offset, /* IN/OUT */
1110 vm_size_t length)
1111{
1112 vm_object_t source;
1113 vm_object_t result;
1114
1115 GIANT_REQUIRED;
1116 source = *object;
1117
1118 /*
1119 * Don't create the new object if the old object isn't shared.
1120 */
1121 if (source != NULL &&
1122 source->ref_count == 1 &&
1123 source->handle == NULL &&
1124 (source->type == OBJT_DEFAULT ||
1125 source->type == OBJT_SWAP))
1126 return;
1127
1128 /*
1129 * Allocate a new object with the given length
1130 */
1131 result = vm_object_allocate(OBJT_DEFAULT, length);
1132 KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing"));
1133
1134 /*
1135 * The new object shadows the source object, adding a reference to it.
1136 * Our caller changes his reference to point to the new object,
1137 * removing a reference to the source object. Net result: no change
1138 * of reference count.
1139 *
1140 * Try to optimize the result object's page color when shadowing
1141 * in order to maintain page coloring consistency in the combined
1142 * shadowed object.
1143 */
1144 result->backing_object = source;
1145 if (source) {
1146 TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list);
1147 source->shadow_count++;
1148 source->generation++;
1149 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1150 }
1151
1152 /*
1153 * Store the offset into the source object, and fix up the offset into
1154 * the new object.
1155 */
1156 result->backing_object_offset = *offset;
1157
1158 /*
1159 * Return the new things
1160 */
1161 *offset = 0;
1162 *object = result;
1163}
1164
1165#define OBSC_TEST_ALL_SHADOWED 0x0001
1166#define OBSC_COLLAPSE_NOWAIT 0x0002
1167#define OBSC_COLLAPSE_WAIT 0x0004
1168
1169static __inline int
1170vm_object_backing_scan(vm_object_t object, int op)
1171{
1172 int s;
1173 int r = 1;
1174 vm_page_t p;
1175 vm_object_t backing_object;
1176 vm_pindex_t backing_offset_index;
1177
1178 s = splvm();
1179 GIANT_REQUIRED;
1180
1181 backing_object = object->backing_object;
1182 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1183
1184 /*
1185 * Initial conditions
1186 */
1187 if (op & OBSC_TEST_ALL_SHADOWED) {
1188 /*
1189 * We do not want to have to test for the existence of
1190 * swap pages in the backing object. XXX but with the
1191 * new swapper this would be pretty easy to do.
1192 *
1193 * XXX what about anonymous MAP_SHARED memory that hasn't
1194 * been ZFOD faulted yet? If we do not test for this, the
1195 * shadow test may succeed! XXX
1196 */
1197 if (backing_object->type != OBJT_DEFAULT) {
1198 splx(s);
1199 return (0);
1200 }
1201 }
1202 if (op & OBSC_COLLAPSE_WAIT) {
1203 vm_object_set_flag(backing_object, OBJ_DEAD);
1204 }
1205
1206 /*
1207 * Our scan
1208 */
1209 p = TAILQ_FIRST(&backing_object->memq);
1210 while (p) {
1211 vm_page_t next = TAILQ_NEXT(p, listq);
1212 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1213
1214 if (op & OBSC_TEST_ALL_SHADOWED) {
1215 vm_page_t pp;
1216
1217 /*
1218 * Ignore pages outside the parent object's range
1219 * and outside the parent object's mapping of the
1220 * backing object.
1221 *
1222 * note that we do not busy the backing object's
1223 * page.
1224 */
1225 if (
1226 p->pindex < backing_offset_index ||
1227 new_pindex >= object->size
1228 ) {
1229 p = next;
1230 continue;
1231 }
1232
1233 /*
1234 * See if the parent has the page or if the parent's
1235 * object pager has the page. If the parent has the
1236 * page but the page is not valid, the parent's
1237 * object pager must have the page.
1238 *
1239 * If this fails, the parent does not completely shadow
1240 * the object and we might as well give up now.
1241 */
1242
1243 pp = vm_page_lookup(object, new_pindex);
1244 if (
1245 (pp == NULL || pp->valid == 0) &&
1246 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1247 ) {
1248 r = 0;
1249 break;
1250 }
1251 }
1252
1253 /*
1254 * Check for busy page
1255 */
1256 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1257 vm_page_t pp;
1258
1259 if (op & OBSC_COLLAPSE_NOWAIT) {
1260 if (
1261 (p->flags & PG_BUSY) ||
1262 !p->valid ||
1263 p->hold_count ||
1264 p->wire_count ||
1265 p->busy
1266 ) {
1267 p = next;
1268 continue;
1269 }
1270 } else if (op & OBSC_COLLAPSE_WAIT) {
1271 if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1272 /*
1273 * If we slept, anything could have
1274 * happened. Since the object is
1275 * marked dead, the backing offset
1276 * should not have changed so we
1277 * just restart our scan.
1278 */
1279 p = TAILQ_FIRST(&backing_object->memq);
1280 continue;
1281 }
1282 }
1283
1284 /*
1285 * Busy the page
1286 */
1287 vm_page_busy(p);
1288
1289 KASSERT(
1290 p->object == backing_object,
1291 ("vm_object_qcollapse(): object mismatch")
1292 );
1293
1294 /*
1295 * Destroy any associated swap
1296 */
1297 if (backing_object->type == OBJT_SWAP) {
1298 swap_pager_freespace(
1299 backing_object,
1300 p->pindex,
1301 1
1302 );
1303 }
1304
1305 if (
1306 p->pindex < backing_offset_index ||
1307 new_pindex >= object->size
1308 ) {
1309 /*
1310 * Page is out of the parent object's range, we
1311 * can simply destroy it.
1312 */
1313 vm_page_protect(p, VM_PROT_NONE);
1314 vm_page_free(p);
1315 p = next;
1316 continue;
1317 }
1318
1319 pp = vm_page_lookup(object, new_pindex);
1320 if (
1321 pp != NULL ||
1322 vm_pager_has_page(object, new_pindex, NULL, NULL)
1323 ) {
1324 /*
1325 * page already exists in parent OR swap exists
1326 * for this location in the parent. Destroy
1327 * the original page from the backing object.
1328 *
1329 * Leave the parent's page alone
1330 */
1331 vm_page_protect(p, VM_PROT_NONE);
1332 vm_page_free(p);
1333 p = next;
1334 continue;
1335 }
1336
1337 /*
1338 * Page does not exist in parent, rename the
1339 * page from the backing object to the main object.
1340 *
1341 * If the page was mapped to a process, it can remain
1342 * mapped through the rename.
1343 */
1344 if ((p->queue - p->pc) == PQ_CACHE)
1345 vm_page_deactivate(p);
1346
1347 vm_page_rename(p, object, new_pindex);
1348 /* page automatically made dirty by rename */
1349 }
1350 p = next;
1351 }
1352 splx(s);
1353 return (r);
1354}
1355
1356
1357/*
1358 * this version of collapse allows the operation to occur earlier and
1359 * when paging_in_progress is true for an object... This is not a complete
1360 * operation, but should plug 99.9% of the rest of the leaks.
1361 */
1362static void
1363vm_object_qcollapse(vm_object_t object)
1364{
1365 vm_object_t backing_object = object->backing_object;
1366
1367 GIANT_REQUIRED;
1368
1369 if (backing_object->ref_count != 1)
1370 return;
1371
1372 backing_object->ref_count += 2;
1373
1374 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1375
1376 backing_object->ref_count -= 2;
1377}
1378
1379/*
1380 * vm_object_collapse:
1381 *
1382 * Collapse an object with the object backing it.
1383 * Pages in the backing object are moved into the
1384 * parent, and the backing object is deallocated.
1385 */
1386void
1387vm_object_collapse(vm_object_t object)
1388{
1389 GIANT_REQUIRED;
1390
1391 while (TRUE) {
1392 vm_object_t backing_object;
1393
1394 /*
1395 * Verify that the conditions are right for collapse:
1396 *
1397 * The object exists and the backing object exists.
1398 */
1399 if (object == NULL)
1400 break;
1401
1402 if ((backing_object = object->backing_object) == NULL)
1403 break;
1404
1405 /*
1406 * we check the backing object first, because it is most likely
1407 * not collapsable.
1408 */
1409 if (backing_object->handle != NULL ||
1410 (backing_object->type != OBJT_DEFAULT &&
1411 backing_object->type != OBJT_SWAP) ||
1412 (backing_object->flags & OBJ_DEAD) ||
1413 object->handle != NULL ||
1414 (object->type != OBJT_DEFAULT &&
1415 object->type != OBJT_SWAP) ||
1416 (object->flags & OBJ_DEAD)) {
1417 break;
1418 }
1419
1420 if (
1421 object->paging_in_progress != 0 ||
1422 backing_object->paging_in_progress != 0
1423 ) {
1424 vm_object_qcollapse(object);
1425 break;
1426 }
1427
1428 /*
1429 * We know that we can either collapse the backing object (if
1430 * the parent is the only reference to it) or (perhaps) have
1431 * the parent bypass the object if the parent happens to shadow
1432 * all the resident pages in the entire backing object.
1433 *
1434 * This is ignoring pager-backed pages such as swap pages.
1435 * vm_object_backing_scan fails the shadowing test in this
1436 * case.
1437 */
1438 if (backing_object->ref_count == 1) {
1439 /*
1440 * If there is exactly one reference to the backing
1441 * object, we can collapse it into the parent.
1442 */
1443 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1444
1445 /*
1446 * Move the pager from backing_object to object.
1447 */
1448 if (backing_object->type == OBJT_SWAP) {
1449 vm_object_pip_add(backing_object, 1);
1450
1451 /*
1452 * scrap the paging_offset junk and do a
1453 * discrete copy. This also removes major
1454 * assumptions about how the swap-pager
1455 * works from where it doesn't belong. The
1456 * new swapper is able to optimize the
1457 * destroy-source case.
1458 */
1459 vm_object_pip_add(object, 1);
1460 swap_pager_copy(
1461 backing_object,
1462 object,
1463 OFF_TO_IDX(object->backing_object_offset), TRUE);
1464 vm_object_pip_wakeup(object);
1465
1466 vm_object_pip_wakeup(backing_object);
1467 }
1468 /*
1469 * Object now shadows whatever backing_object did.
1470 * Note that the reference to
1471 * backing_object->backing_object moves from within
1472 * backing_object to within object.
1473 */
1474 TAILQ_REMOVE(
1475 &object->backing_object->shadow_head,
1476 object,
1477 shadow_list
1478 );
1479 object->backing_object->shadow_count--;
1480 object->backing_object->generation++;
1481 if (backing_object->backing_object) {
1482 TAILQ_REMOVE(
1483 &backing_object->backing_object->shadow_head,
1484 backing_object,
1485 shadow_list
1486 );
1487 backing_object->backing_object->shadow_count--;
1488 backing_object->backing_object->generation++;
1489 }
1490 object->backing_object = backing_object->backing_object;
1491 if (object->backing_object) {
1492 TAILQ_INSERT_TAIL(
1493 &object->backing_object->shadow_head,
1494 object,
1495 shadow_list
1496 );
1497 object->backing_object->shadow_count++;
1498 object->backing_object->generation++;
1499 }
1500
1501 object->backing_object_offset +=
1502 backing_object->backing_object_offset;
1503
1504 /*
1505 * Discard backing_object.
1506 *
1507 * Since the backing object has no pages, no pager left,
1508 * and no object references within it, all that is
1509 * necessary is to dispose of it.
1510 */
1511 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1512 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
1513
1514 TAILQ_REMOVE(
1515 &vm_object_list,
1516 backing_object,
1517 object_list
1518 );
1519
1520 zfree(obj_zone, backing_object);
1521
1522 object_collapses++;
1523 } else {
1524 vm_object_t new_backing_object;
1525
1526 /*
1527 * If we do not entirely shadow the backing object,
1528 * there is nothing we can do so we give up.
1529 */
1530 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1531 break;
1532 }
1533
1534 /*
1535 * Make the parent shadow the next object in the
1536 * chain. Deallocating backing_object will not remove
1537 * it, since its reference count is at least 2.
1538 */
1539 TAILQ_REMOVE(
1540 &backing_object->shadow_head,
1541 object,
1542 shadow_list
1543 );
1544 backing_object->shadow_count--;
1545 backing_object->generation++;
1546
1547 new_backing_object = backing_object->backing_object;
1548 if ((object->backing_object = new_backing_object) != NULL) {
1549 vm_object_reference(new_backing_object);
1550 TAILQ_INSERT_TAIL(
1551 &new_backing_object->shadow_head,
1552 object,
1553 shadow_list
1554 );
1555 new_backing_object->shadow_count++;
1556 new_backing_object->generation++;
1557 object->backing_object_offset +=
1558 backing_object->backing_object_offset;
1559 }
1560
1561 /*
1562 * Drop the reference count on backing_object. Since
1563 * its ref_count was at least 2, it will not vanish;
1564 * so we don't need to call vm_object_deallocate, but
1565 * we do anyway.
1566 */
1567 vm_object_deallocate(backing_object);
1568 object_bypasses++;
1569 }
1570
1571 /*
1572 * Try again with this object's new backing object.
1573 */
1574 }
1575}
1576
1577/*
1578 * vm_object_page_remove: [internal]
1579 *
1580 * Removes all physical pages in the specified
1581 * object range from the object's list of pages.
1582 *
1583 * The object must be locked.
1584 */
1585void
1586vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, boolean_t clean_only)
1587{
1588 vm_page_t p, next;
1589 unsigned int size;
1590 int all;
1591
1592 GIANT_REQUIRED;
1593
1594 if (object == NULL ||
1595 object->resident_page_count == 0)
1596 return;
1597
1598 all = ((end == 0) && (start == 0));
1599
1600 /*
1601 * Since physically-backed objects do not use managed pages, we can't
1602 * remove pages from the object (we must instead remove the page
1603 * references, and then destroy the object).
1604 */
1605 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object"));
1606
1607 vm_object_pip_add(object, 1);
1608again:
1609 size = end - start;
1610 if (all || size > object->resident_page_count / 4) {
1611 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
1612 next = TAILQ_NEXT(p, listq);
1613 if (all || ((start <= p->pindex) && (p->pindex < end))) {
1614 if (p->wire_count != 0) {
1615 vm_page_protect(p, VM_PROT_NONE);
1616 if (!clean_only)
1617 p->valid = 0;
1618 continue;
1619 }
1620
1621 /*
1622 * The busy flags are only cleared at
1623 * interrupt -- minimize the spl transitions
1624 */
1625 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1626 goto again;
1627
1628 if (clean_only && p->valid) {
1629 vm_page_test_dirty(p);
1630 if (p->valid & p->dirty)
1631 continue;
1632 }
1633
1634 vm_page_busy(p);
1635 vm_page_protect(p, VM_PROT_NONE);
1636 vm_page_free(p);
1637 }
1638 }
1639 } else {
1640 while (size > 0) {
1641 if ((p = vm_page_lookup(object, start)) != 0) {
1642
1643 if (p->wire_count != 0) {
1644 vm_page_protect(p, VM_PROT_NONE);
1645 if (!clean_only)
1646 p->valid = 0;
1647 start += 1;
1648 size -= 1;
1649 continue;
1650 }
1651
1652 /*
1653 * The busy flags are only cleared at
1654 * interrupt -- minimize the spl transitions
1655 */
1656 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1657 goto again;
1658
1659 if (clean_only && p->valid) {
1660 vm_page_test_dirty(p);
1661 if (p->valid & p->dirty) {
1662 start += 1;
1663 size -= 1;
1664 continue;
1665 }
1666 }
1667
1668 vm_page_busy(p);
1669 vm_page_protect(p, VM_PROT_NONE);
1670 vm_page_free(p);
1671 }
1672 start += 1;
1673 size -= 1;
1674 }
1675 }
1676 vm_object_pip_wakeup(object);
1677}
1678
1679/*
1680 * Routine: vm_object_coalesce
1681 * Function: Coalesces two objects backing up adjoining
1682 * regions of memory into a single object.
1683 *
1684 * returns TRUE if objects were combined.
1685 *
1686 * NOTE: Only works at the moment if the second object is NULL -
1687 * if it's not, which object do we lock first?
1688 *
1689 * Parameters:
1690 * prev_object First object to coalesce
1691 * prev_offset Offset into prev_object
1692 * next_object Second object into coalesce
1693 * next_offset Offset into next_object
1694 *
1695 * prev_size Size of reference to prev_object
1696 * next_size Size of reference to next_object
1697 *
1698 * Conditions:
1699 * The object must *not* be locked.
1700 */
1701boolean_t
1702vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size)
1703{
1704 vm_pindex_t next_pindex;
1705
1706 GIANT_REQUIRED;
1707
1708 if (prev_object == NULL) {
1709 return (TRUE);
1710 }
1711
1712 if (prev_object->type != OBJT_DEFAULT &&
1713 prev_object->type != OBJT_SWAP) {
1714 return (FALSE);
1715 }
1716
1717 /*
1718 * Try to collapse the object first
1719 */
1720 vm_object_collapse(prev_object);
1721
1722 /*
1723 * Can't coalesce if: . more than one reference . paged out . shadows
1724 * another object . has a copy elsewhere (any of which mean that the
1725 * pages not mapped to prev_entry may be in use anyway)
1726 */
1727 if (prev_object->backing_object != NULL) {
1728 return (FALSE);
1729 }
1730
1731 prev_size >>= PAGE_SHIFT;
1732 next_size >>= PAGE_SHIFT;
1733 next_pindex = prev_pindex + prev_size;
1734
1735 if ((prev_object->ref_count > 1) &&
1736 (prev_object->size != next_pindex)) {
1737 return (FALSE);
1738 }
1739
1740 /*
1741 * Remove any pages that may still be in the object from a previous
1742 * deallocation.
1743 */
1744 if (next_pindex < prev_object->size) {
1745 vm_object_page_remove(prev_object,
1746 next_pindex,
1747 next_pindex + next_size, FALSE);
1748 if (prev_object->type == OBJT_SWAP)
1749 swap_pager_freespace(prev_object,
1750 next_pindex, next_size);
1751 }
1752
1753 /*
1754 * Extend the object if necessary.
1755 */
1756 if (next_pindex + next_size > prev_object->size)
1757 prev_object->size = next_pindex + next_size;
1758
1759 return (TRUE);
1760}
1761
1762void
1763vm_object_set_writeable_dirty(vm_object_t object)
1764{
1765 struct vnode *vp;
1766
1767 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1768 if (object->type == OBJT_VNODE &&
1769 (vp = (struct vnode *)object->handle) != NULL) {
1770 if ((vp->v_flag & VOBJDIRTY) == 0) {
1771 mtx_lock(&vp->v_interlock);
1772 vp->v_flag |= VOBJDIRTY;
1773 mtx_unlock(&vp->v_interlock);
1774 }
1775 }
1776}
1777
1778#include "opt_ddb.h"
1779#ifdef DDB
1780#include <sys/kernel.h>
1781
1782#include <sys/cons.h>
1783
1784#include <ddb/ddb.h>
1785
1786static int
1787_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1788{
1789 vm_map_t tmpm;
1790 vm_map_entry_t tmpe;
1791 vm_object_t obj;
1792 int entcount;
1793
1794 if (map == 0)
1795 return 0;
1796
1797 if (entry == 0) {
1798 tmpe = map->header.next;
1799 entcount = map->nentries;
1800 while (entcount-- && (tmpe != &map->header)) {
1801 if (_vm_object_in_map(map, object, tmpe)) {
1802 return 1;
1803 }
1804 tmpe = tmpe->next;
1805 }
1806 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1807 tmpm = entry->object.sub_map;
1808 tmpe = tmpm->header.next;
1809 entcount = tmpm->nentries;
1810 while (entcount-- && tmpe != &tmpm->header) {
1811 if (_vm_object_in_map(tmpm, object, tmpe)) {
1812 return 1;
1813 }
1814 tmpe = tmpe->next;
1815 }
1816 } else if ((obj = entry->object.vm_object) != NULL) {
1817 for (; obj; obj = obj->backing_object)
1818 if (obj == object) {
1819 return 1;
1820 }
1821 }
1822 return 0;
1823}
1824
1825static int
1826vm_object_in_map(vm_object_t object)
1827{
1828 struct proc *p;
1829
1830 /* sx_slock(&allproc_lock); */
1831 LIST_FOREACH(p, &allproc, p_list) {
1832 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1833 continue;
1834 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1835 /* sx_sunlock(&allproc_lock); */
1836 return 1;
1837 }
1838 }
1839 /* sx_sunlock(&allproc_lock); */
1840 if (_vm_object_in_map(kernel_map, object, 0))
1841 return 1;
1842 if (_vm_object_in_map(kmem_map, object, 0))
1843 return 1;
1844 if (_vm_object_in_map(pager_map, object, 0))
1845 return 1;
1846 if (_vm_object_in_map(buffer_map, object, 0))
1847 return 1;
1848 return 0;
1849}
1850
1851DB_SHOW_COMMAND(vmochk, vm_object_check)
1852{
1853 vm_object_t object;
1854
1855 /*
1856 * make sure that internal objs are in a map somewhere
1857 * and none have zero ref counts.
1858 */
1859 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1860 if (object->handle == NULL &&
1861 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
1862 if (object->ref_count == 0) {
1863 db_printf("vmochk: internal obj has zero ref count: %ld\n",
1864 (long)object->size);
1865 }
1866 if (!vm_object_in_map(object)) {
1867 db_printf(
1868 "vmochk: internal obj is not in a map: "
1869 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
1870 object->ref_count, (u_long)object->size,
1871 (u_long)object->size,
1872 (void *)object->backing_object);
1873 }
1874 }
1875 }
1876}
1877
1878/*
1879 * vm_object_print: [ debug ]
1880 */
1881DB_SHOW_COMMAND(object, vm_object_print_static)
1882{
1883 /* XXX convert args. */
1884 vm_object_t object = (vm_object_t)addr;
1885 boolean_t full = have_addr;
1886
1887 vm_page_t p;
1888
1889 /* XXX count is an (unused) arg. Avoid shadowing it. */
1890#define count was_count
1891
1892 int count;
1893
1894 if (object == NULL)
1895 return;
1896
1897 db_iprintf(
1898 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
1899 object, (int)object->type, (u_long)object->size,
1900 object->resident_page_count, object->ref_count, object->flags);
1901 /*
1902 * XXX no %qd in kernel. Truncate object->backing_object_offset.
1903 */
1904 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
1905 object->shadow_count,
1906 object->backing_object ? object->backing_object->ref_count : 0,
1907 object->backing_object, (long)object->backing_object_offset);
1908
1909 if (!full)
1910 return;
1911
1912 db_indent += 2;
1913 count = 0;
1914 TAILQ_FOREACH(p, &object->memq, listq) {
1915 if (count == 0)
1916 db_iprintf("memory:=");
1917 else if (count == 6) {
1918 db_printf("\n");
1919 db_iprintf(" ...");
1920 count = 0;
1921 } else
1922 db_printf(",");
1923 count++;
1924
1925 db_printf("(off=0x%lx,page=0x%lx)",
1926 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
1927 }
1928 if (count != 0)
1929 db_printf("\n");
1930 db_indent -= 2;
1931}
1932
1933/* XXX. */
1934#undef count
1935
1936/* XXX need this non-static entry for calling from vm_map_print. */
1937void
1938vm_object_print(
1939 /* db_expr_t */ long addr,
1940 boolean_t have_addr,
1941 /* db_expr_t */ long count,
1942 char *modif)
1943{
1944 vm_object_print_static(addr, have_addr, count, modif);
1945}
1946
1947DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
1948{
1949 vm_object_t object;
1950 int nl = 0;
1951 int c;
1952
1953 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1954 vm_pindex_t idx, fidx;
1955 vm_pindex_t osize;
1956 vm_offset_t pa = -1, padiff;
1957 int rcount;
1958 vm_page_t m;
1959
1960 db_printf("new object: %p\n", (void *)object);
1961 if (nl > 18) {
1962 c = cngetc();
1963 if (c != ' ')
1964 return;
1965 nl = 0;
1966 }
1967 nl++;
1968 rcount = 0;
1969 fidx = 0;
1970 osize = object->size;
1971 if (osize > 128)
1972 osize = 128;
1973 for (idx = 0; idx < osize; idx++) {
1974 m = vm_page_lookup(object, idx);
1975 if (m == NULL) {
1976 if (rcount) {
1977 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1978 (long)fidx, rcount, (long)pa);
1979 if (nl > 18) {
1980 c = cngetc();
1981 if (c != ' ')
1982 return;
1983 nl = 0;
1984 }
1985 nl++;
1986 rcount = 0;
1987 }
1988 continue;
1989 }
1990
1991
1992 if (rcount &&
1993 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
1994 ++rcount;
1995 continue;
1996 }
1997 if (rcount) {
1998 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
1999 padiff >>= PAGE_SHIFT;
2000 padiff &= PQ_L2_MASK;
2001 if (padiff == 0) {
2002 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
2003 ++rcount;
2004 continue;
2005 }
2006 db_printf(" index(%ld)run(%d)pa(0x%lx)",
2007 (long)fidx, rcount, (long)pa);
2008 db_printf("pd(%ld)\n", (long)padiff);
2009 if (nl > 18) {
2010 c = cngetc();
2011 if (c != ' ')
2012 return;
2013 nl = 0;
2014 }
2015 nl++;
2016 }
2017 fidx = idx;
2018 pa = VM_PAGE_TO_PHYS(m);
2019 rcount = 1;
2020 }
2021 if (rcount) {
2022 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2023 (long)fidx, rcount, (long)pa);
2024 if (nl > 18) {
2025 c = cngetc();
2026 if (c != ' ')
2027 return;
2028 nl = 0;
2029 }
2030 nl++;
2031 }
2032 }
2033}
2034#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 92654 2002-03-19 09:11:49Z jeff $
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 int object_hash_rand;
151static vm_zone_t obj_zone;
152#define VM_OBJECTS_INIT 256
153
154static void vm_object_zinit(void *mem, int size);
155
156#ifdef INVARIANTS
157static void vm_object_zdtor(void *mem, int size, void *arg);
158
159static void
160vm_object_zdtor(void *mem, int size, void *arg)
161{
162 vm_object_t object;
163
164 object = (vm_object_t)mem;
165 KASSERT(object->paging_in_progress == 0,
166 ("object %p paging_in_progress = %d",
167 object, object->paging_in_progress));
168 KASSERT(object->resident_page_count == 0,
169 ("object %p resident_page_count = %d",
170 object, object->resident_page_count));
171 KASSERT(object->shadow_count == 0,
172 ("object %p shadow_count = %d",
173 object, object->shadow_count));
174}
175#endif
176
177static void
178vm_object_zinit(void *mem, int size)
179{
180 vm_object_t object;
181
182 object = (vm_object_t)mem;
183
184 /* These are true for any object that has been freed */
185 object->paging_in_progress = 0;
186 object->resident_page_count = 0;
187 object->shadow_count = 0;
188}
189
190void
191_vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object)
192{
193 int incr;
194
195 GIANT_REQUIRED;
196
197 TAILQ_INIT(&object->memq);
198 TAILQ_INIT(&object->shadow_head);
199
200 object->type = type;
201 object->size = size;
202 object->ref_count = 1;
203 object->flags = 0;
204 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
205 vm_object_set_flag(object, OBJ_ONEMAPPING);
206 object->pg_color = next_index;
207 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
208 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
209 else
210 incr = size;
211 next_index = (next_index + incr) & PQ_L2_MASK;
212 object->handle = NULL;
213 object->backing_object = NULL;
214 object->backing_object_offset = (vm_ooffset_t) 0;
215 /*
216 * Try to generate a number that will spread objects out in the
217 * hash table. We 'wipe' new objects across the hash in 128 page
218 * increments plus 1 more to offset it a little more by the time
219 * it wraps around.
220 */
221 object->hash_rand = object_hash_rand - 129;
222
223 object->generation++;
224
225 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
226
227 object_hash_rand = object->hash_rand;
228}
229
230/*
231 * vm_object_init:
232 *
233 * Initialize the VM objects module.
234 */
235void
236vm_object_init(void)
237{
238 GIANT_REQUIRED;
239
240 TAILQ_INIT(&vm_object_list);
241 mtx_init(&vm_object_list_mtx, "vm object_list", MTX_DEF);
242
243 kernel_object = &kernel_object_store;
244 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
245 kernel_object);
246
247 kmem_object = &kmem_object_store;
248 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
249 kmem_object);
250 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
251#ifdef INVARIANTS
252 vm_object_zdtor,
253#else
254 NULL,
255#endif
256 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
257 uma_prealloc(obj_zone, VM_OBJECTS_INIT);
258}
259
260void
261vm_object_init2(void)
262{
263}
264
265void
266vm_object_set_flag(vm_object_t object, u_short bits)
267{
268 GIANT_REQUIRED;
269 object->flags |= bits;
270}
271
272void
273vm_object_clear_flag(vm_object_t object, u_short bits)
274{
275 GIANT_REQUIRED;
276 object->flags &= ~bits;
277}
278
279void
280vm_object_pip_add(vm_object_t object, short i)
281{
282 GIANT_REQUIRED;
283 object->paging_in_progress += i;
284}
285
286void
287vm_object_pip_subtract(vm_object_t object, short i)
288{
289 GIANT_REQUIRED;
290 object->paging_in_progress -= i;
291}
292
293void
294vm_object_pip_wakeup(vm_object_t object)
295{
296 GIANT_REQUIRED;
297 object->paging_in_progress--;
298 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
299 vm_object_clear_flag(object, OBJ_PIPWNT);
300 wakeup(object);
301 }
302}
303
304void
305vm_object_pip_wakeupn(vm_object_t object, short i)
306{
307 GIANT_REQUIRED;
308 if (i)
309 object->paging_in_progress -= i;
310 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
311 vm_object_clear_flag(object, OBJ_PIPWNT);
312 wakeup(object);
313 }
314}
315
316void
317vm_object_pip_sleep(vm_object_t object, char *waitid)
318{
319 GIANT_REQUIRED;
320 if (object->paging_in_progress) {
321 int s = splvm();
322 if (object->paging_in_progress) {
323 vm_object_set_flag(object, OBJ_PIPWNT);
324 tsleep(object, PVM, waitid, 0);
325 }
326 splx(s);
327 }
328}
329
330void
331vm_object_pip_wait(vm_object_t object, char *waitid)
332{
333 GIANT_REQUIRED;
334 while (object->paging_in_progress)
335 vm_object_pip_sleep(object, waitid);
336}
337
338/*
339 * vm_object_allocate:
340 *
341 * Returns a new object with the given size.
342 */
343vm_object_t
344vm_object_allocate(objtype_t type, vm_size_t size)
345{
346 vm_object_t result;
347
348 GIANT_REQUIRED;
349
350 result = (vm_object_t) zalloc(obj_zone);
351 _vm_object_allocate(type, size, result);
352
353 return (result);
354}
355
356
357/*
358 * vm_object_reference:
359 *
360 * Gets another reference to the given object.
361 */
362void
363vm_object_reference(vm_object_t object)
364{
365 GIANT_REQUIRED;
366
367 if (object == NULL)
368 return;
369
370#if 0
371 /* object can be re-referenced during final cleaning */
372 KASSERT(!(object->flags & OBJ_DEAD),
373 ("vm_object_reference: attempting to reference dead obj"));
374#endif
375
376 object->ref_count++;
377 if (object->type == OBJT_VNODE) {
378 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) {
379 printf("vm_object_reference: delay in getting object\n");
380 }
381 }
382}
383
384/*
385 * handle deallocating a object of type OBJT_VNODE
386 */
387void
388vm_object_vndeallocate(vm_object_t object)
389{
390 struct vnode *vp = (struct vnode *) object->handle;
391
392 GIANT_REQUIRED;
393 KASSERT(object->type == OBJT_VNODE,
394 ("vm_object_vndeallocate: not a vnode object"));
395 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
396#ifdef INVARIANTS
397 if (object->ref_count == 0) {
398 vprint("vm_object_vndeallocate", vp);
399 panic("vm_object_vndeallocate: bad object reference count");
400 }
401#endif
402
403 object->ref_count--;
404 if (object->ref_count == 0) {
405 vp->v_flag &= ~VTEXT;
406 vm_object_clear_flag(object, OBJ_OPT);
407 }
408 /*
409 * vrele may need a vop lock
410 */
411 vrele(vp);
412}
413
414/*
415 * vm_object_deallocate:
416 *
417 * Release a reference to the specified object,
418 * gained either through a vm_object_allocate
419 * or a vm_object_reference call. When all references
420 * are gone, storage associated with this object
421 * may be relinquished.
422 *
423 * No object may be locked.
424 */
425void
426vm_object_deallocate(vm_object_t object)
427{
428 vm_object_t temp;
429
430 GIANT_REQUIRED;
431
432 while (object != NULL) {
433
434 if (object->type == OBJT_VNODE) {
435 vm_object_vndeallocate(object);
436 return;
437 }
438
439 KASSERT(object->ref_count != 0,
440 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
441
442 /*
443 * If the reference count goes to 0 we start calling
444 * vm_object_terminate() on the object chain.
445 * A ref count of 1 may be a special case depending on the
446 * shadow count being 0 or 1.
447 */
448 object->ref_count--;
449 if (object->ref_count > 1) {
450 return;
451 } else if (object->ref_count == 1) {
452 if (object->shadow_count == 0) {
453 vm_object_set_flag(object, OBJ_ONEMAPPING);
454 } else if ((object->shadow_count == 1) &&
455 (object->handle == NULL) &&
456 (object->type == OBJT_DEFAULT ||
457 object->type == OBJT_SWAP)) {
458 vm_object_t robject;
459
460 robject = TAILQ_FIRST(&object->shadow_head);
461 KASSERT(robject != NULL,
462 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
463 object->ref_count,
464 object->shadow_count));
465 if ((robject->handle == NULL) &&
466 (robject->type == OBJT_DEFAULT ||
467 robject->type == OBJT_SWAP)) {
468
469 robject->ref_count++;
470
471 while (
472 robject->paging_in_progress ||
473 object->paging_in_progress
474 ) {
475 vm_object_pip_sleep(robject, "objde1");
476 vm_object_pip_sleep(object, "objde2");
477 }
478
479 if (robject->ref_count == 1) {
480 robject->ref_count--;
481 object = robject;
482 goto doterm;
483 }
484
485 object = robject;
486 vm_object_collapse(object);
487 continue;
488 }
489 }
490
491 return;
492
493 }
494
495doterm:
496
497 temp = object->backing_object;
498 if (temp) {
499 TAILQ_REMOVE(&temp->shadow_head, object, shadow_list);
500 temp->shadow_count--;
501 if (temp->ref_count == 0)
502 vm_object_clear_flag(temp, OBJ_OPT);
503 temp->generation++;
504 object->backing_object = NULL;
505 }
506 /*
507 * Don't double-terminate, we could be in a termination
508 * recursion due to the terminate having to sync data
509 * to disk.
510 */
511 if ((object->flags & OBJ_DEAD) == 0)
512 vm_object_terminate(object);
513 object = temp;
514 }
515}
516
517/*
518 * vm_object_terminate actually destroys the specified object, freeing
519 * up all previously used resources.
520 *
521 * The object must be locked.
522 * This routine may block.
523 */
524void
525vm_object_terminate(vm_object_t object)
526{
527 vm_page_t p;
528 int s;
529
530 GIANT_REQUIRED;
531
532 /*
533 * Make sure no one uses us.
534 */
535 vm_object_set_flag(object, OBJ_DEAD);
536
537 /*
538 * wait for the pageout daemon to be done with the object
539 */
540 vm_object_pip_wait(object, "objtrm");
541
542 KASSERT(!object->paging_in_progress,
543 ("vm_object_terminate: pageout in progress"));
544
545 /*
546 * Clean and free the pages, as appropriate. All references to the
547 * object are gone, so we don't need to lock it.
548 */
549 if (object->type == OBJT_VNODE) {
550 struct vnode *vp;
551
552 /*
553 * Freeze optimized copies.
554 */
555 vm_freeze_copyopts(object, 0, object->size);
556
557 /*
558 * Clean pages and flush buffers.
559 */
560 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
561
562 vp = (struct vnode *) object->handle;
563 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
564 }
565
566 KASSERT(object->ref_count == 0,
567 ("vm_object_terminate: object with references, ref_count=%d",
568 object->ref_count));
569
570 /*
571 * Now free any remaining pages. For internal objects, this also
572 * removes them from paging queues. Don't free wired pages, just
573 * remove them from the object.
574 */
575 s = splvm();
576 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
577 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
578 ("vm_object_terminate: freeing busy page %p "
579 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
580 if (p->wire_count == 0) {
581 vm_page_busy(p);
582 vm_page_free(p);
583 cnt.v_pfree++;
584 } else {
585 vm_page_busy(p);
586 vm_page_remove(p);
587 }
588 }
589 splx(s);
590
591 /*
592 * Let the pager know object is dead.
593 */
594 vm_pager_deallocate(object);
595
596 /*
597 * Remove the object from the global object list.
598 */
599 mtx_lock(&vm_object_list_mtx);
600 TAILQ_REMOVE(&vm_object_list, object, object_list);
601 mtx_unlock(&vm_object_list_mtx);
602
603 wakeup(object);
604
605 /*
606 * Free the space for the object.
607 */
608 zfree(obj_zone, object);
609}
610
611/*
612 * vm_object_page_clean
613 *
614 * Clean all dirty pages in the specified range of object. Leaves page
615 * on whatever queue it is currently on. If NOSYNC is set then do not
616 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
617 * leaving the object dirty.
618 *
619 * Odd semantics: if start == end, we clean everything.
620 *
621 * The object must be locked.
622 */
623void
624vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
625{
626 vm_page_t p, np;
627 vm_offset_t tstart, tend;
628 vm_pindex_t pi;
629 struct vnode *vp;
630 int clearobjflags;
631 int pagerflags;
632 int curgeneration;
633
634 GIANT_REQUIRED;
635
636 if (object->type != OBJT_VNODE ||
637 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
638 return;
639
640 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : 0;
641 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
642
643 vp = object->handle;
644
645 vm_object_set_flag(object, OBJ_CLEANING);
646
647 tstart = start;
648 if (end == 0) {
649 tend = object->size;
650 } else {
651 tend = end;
652 }
653
654 /*
655 * If the caller is smart and only msync()s a range he knows is
656 * dirty, we may be able to avoid an object scan. This results in
657 * a phenominal improvement in performance. We cannot do this
658 * as a matter of course because the object may be huge - e.g.
659 * the size might be in the gigabytes or terrabytes.
660 */
661 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
662 vm_offset_t tscan;
663 int scanlimit;
664 int scanreset;
665
666 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
667 if (scanreset < 16)
668 scanreset = 16;
669
670 scanlimit = scanreset;
671 tscan = tstart;
672 while (tscan < tend) {
673 curgeneration = object->generation;
674 p = vm_page_lookup(object, tscan);
675 if (p == NULL || p->valid == 0 ||
676 (p->queue - p->pc) == PQ_CACHE) {
677 if (--scanlimit == 0)
678 break;
679 ++tscan;
680 continue;
681 }
682 vm_page_test_dirty(p);
683 if ((p->dirty & p->valid) == 0) {
684 if (--scanlimit == 0)
685 break;
686 ++tscan;
687 continue;
688 }
689 /*
690 * If we have been asked to skip nosync pages and
691 * this is a nosync page, we can't continue.
692 */
693 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
694 if (--scanlimit == 0)
695 break;
696 ++tscan;
697 continue;
698 }
699 scanlimit = scanreset;
700
701 /*
702 * This returns 0 if it was unable to busy the first
703 * page (i.e. had to sleep).
704 */
705 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
706 }
707
708 /*
709 * If everything was dirty and we flushed it successfully,
710 * and the requested range is not the entire object, we
711 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
712 * return immediately.
713 */
714 if (tscan >= tend && (tstart || tend < object->size)) {
715 vm_object_clear_flag(object, OBJ_CLEANING);
716 return;
717 }
718 }
719
720 /*
721 * Generally set CLEANCHK interlock and make the page read-only so
722 * we can then clear the object flags.
723 *
724 * However, if this is a nosync mmap then the object is likely to
725 * stay dirty so do not mess with the page and do not clear the
726 * object flags.
727 */
728 clearobjflags = 1;
729
730 TAILQ_FOREACH(p, &object->memq, listq) {
731 vm_page_flag_set(p, PG_CLEANCHK);
732 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
733 clearobjflags = 0;
734 else
735 vm_page_protect(p, VM_PROT_READ);
736 }
737
738 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
739 struct vnode *vp;
740
741 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
742 if (object->type == OBJT_VNODE &&
743 (vp = (struct vnode *)object->handle) != NULL) {
744 if (vp->v_flag & VOBJDIRTY) {
745 mtx_lock(&vp->v_interlock);
746 vp->v_flag &= ~VOBJDIRTY;
747 mtx_unlock(&vp->v_interlock);
748 }
749 }
750 }
751
752rescan:
753 curgeneration = object->generation;
754
755 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
756 int n;
757
758 np = TAILQ_NEXT(p, listq);
759
760again:
761 pi = p->pindex;
762 if (((p->flags & PG_CLEANCHK) == 0) ||
763 (pi < tstart) || (pi >= tend) ||
764 (p->valid == 0) ||
765 ((p->queue - p->pc) == PQ_CACHE)) {
766 vm_page_flag_clear(p, PG_CLEANCHK);
767 continue;
768 }
769
770 vm_page_test_dirty(p);
771 if ((p->dirty & p->valid) == 0) {
772 vm_page_flag_clear(p, PG_CLEANCHK);
773 continue;
774 }
775
776 /*
777 * If we have been asked to skip nosync pages and this is a
778 * nosync page, skip it. Note that the object flags were
779 * not cleared in this case so we do not have to set them.
780 */
781 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
782 vm_page_flag_clear(p, PG_CLEANCHK);
783 continue;
784 }
785
786 n = vm_object_page_collect_flush(object, p,
787 curgeneration, pagerflags);
788 if (n == 0)
789 goto rescan;
790
791 if (object->generation != curgeneration)
792 goto rescan;
793
794 /*
795 * Try to optimize the next page. If we can't we pick up
796 * our (random) scan where we left off.
797 */
798 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
799 if ((p = vm_page_lookup(object, pi + n)) != NULL)
800 goto again;
801 }
802 }
803
804#if 0
805 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
806#endif
807
808 vm_object_clear_flag(object, OBJ_CLEANING);
809 return;
810}
811
812static int
813vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
814{
815 int runlen;
816 int s;
817 int maxf;
818 int chkb;
819 int maxb;
820 int i;
821 vm_pindex_t pi;
822 vm_page_t maf[vm_pageout_page_count];
823 vm_page_t mab[vm_pageout_page_count];
824 vm_page_t ma[vm_pageout_page_count];
825
826 s = splvm();
827 pi = p->pindex;
828 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
829 if (object->generation != curgeneration) {
830 splx(s);
831 return(0);
832 }
833 }
834
835 maxf = 0;
836 for(i = 1; i < vm_pageout_page_count; i++) {
837 vm_page_t tp;
838
839 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
840 if ((tp->flags & PG_BUSY) ||
841 (tp->flags & PG_CLEANCHK) == 0 ||
842 (tp->busy != 0))
843 break;
844 if((tp->queue - tp->pc) == PQ_CACHE) {
845 vm_page_flag_clear(tp, PG_CLEANCHK);
846 break;
847 }
848 vm_page_test_dirty(tp);
849 if ((tp->dirty & tp->valid) == 0) {
850 vm_page_flag_clear(tp, PG_CLEANCHK);
851 break;
852 }
853 maf[ i - 1 ] = tp;
854 maxf++;
855 continue;
856 }
857 break;
858 }
859
860 maxb = 0;
861 chkb = vm_pageout_page_count - maxf;
862 if (chkb) {
863 for(i = 1; i < chkb;i++) {
864 vm_page_t tp;
865
866 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
867 if ((tp->flags & PG_BUSY) ||
868 (tp->flags & PG_CLEANCHK) == 0 ||
869 (tp->busy != 0))
870 break;
871 if ((tp->queue - tp->pc) == PQ_CACHE) {
872 vm_page_flag_clear(tp, PG_CLEANCHK);
873 break;
874 }
875 vm_page_test_dirty(tp);
876 if ((tp->dirty & tp->valid) == 0) {
877 vm_page_flag_clear(tp, PG_CLEANCHK);
878 break;
879 }
880 mab[ i - 1 ] = tp;
881 maxb++;
882 continue;
883 }
884 break;
885 }
886 }
887
888 for(i = 0; i < maxb; i++) {
889 int index = (maxb - i) - 1;
890 ma[index] = mab[i];
891 vm_page_flag_clear(ma[index], PG_CLEANCHK);
892 }
893 vm_page_flag_clear(p, PG_CLEANCHK);
894 ma[maxb] = p;
895 for(i = 0; i < maxf; i++) {
896 int index = (maxb + i) + 1;
897 ma[index] = maf[i];
898 vm_page_flag_clear(ma[index], PG_CLEANCHK);
899 }
900 runlen = maxb + maxf + 1;
901
902 splx(s);
903 vm_pageout_flush(ma, runlen, pagerflags);
904 for (i = 0; i < runlen; i++) {
905 if (ma[i]->valid & ma[i]->dirty) {
906 vm_page_protect(ma[i], VM_PROT_READ);
907 vm_page_flag_set(ma[i], PG_CLEANCHK);
908
909 /*
910 * maxf will end up being the actual number of pages
911 * we wrote out contiguously, non-inclusive of the
912 * first page. We do not count look-behind pages.
913 */
914 if (i >= maxb + 1 && (maxf > i - maxb - 1))
915 maxf = i - maxb - 1;
916 }
917 }
918 return(maxf + 1);
919}
920
921/*
922 * Same as vm_object_pmap_copy, except range checking really
923 * works, and is meant for small sections of an object.
924 *
925 * This code protects resident pages by making them read-only
926 * and is typically called on a fork or split when a page
927 * is converted to copy-on-write.
928 *
929 * NOTE: If the page is already at VM_PROT_NONE, calling
930 * vm_page_protect will have no effect.
931 */
932void
933vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
934{
935 vm_pindex_t idx;
936 vm_page_t p;
937
938 GIANT_REQUIRED;
939
940 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
941 return;
942
943 for (idx = start; idx < end; idx++) {
944 p = vm_page_lookup(object, idx);
945 if (p == NULL)
946 continue;
947 vm_page_protect(p, VM_PROT_READ);
948 }
949}
950
951/*
952 * vm_object_pmap_remove:
953 *
954 * Removes all physical pages in the specified
955 * object range from all physical maps.
956 *
957 * The object must *not* be locked.
958 */
959void
960vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
961{
962 vm_page_t p;
963
964 GIANT_REQUIRED;
965 if (object == NULL)
966 return;
967 TAILQ_FOREACH(p, &object->memq, listq) {
968 if (p->pindex >= start && p->pindex < end)
969 vm_page_protect(p, VM_PROT_NONE);
970 }
971 if ((start == 0) && (object->size == end))
972 vm_object_clear_flag(object, OBJ_WRITEABLE);
973}
974
975/*
976 * vm_object_madvise:
977 *
978 * Implements the madvise function at the object/page level.
979 *
980 * MADV_WILLNEED (any object)
981 *
982 * Activate the specified pages if they are resident.
983 *
984 * MADV_DONTNEED (any object)
985 *
986 * Deactivate the specified pages if they are resident.
987 *
988 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
989 * OBJ_ONEMAPPING only)
990 *
991 * Deactivate and clean the specified pages if they are
992 * resident. This permits the process to reuse the pages
993 * without faulting or the kernel to reclaim the pages
994 * without I/O.
995 */
996void
997vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
998{
999 vm_pindex_t end, tpindex;
1000 vm_object_t tobject;
1001 vm_page_t m;
1002
1003 GIANT_REQUIRED;
1004 if (object == NULL)
1005 return;
1006
1007 end = pindex + count;
1008
1009 /*
1010 * Locate and adjust resident pages
1011 */
1012 for (; pindex < end; pindex += 1) {
1013relookup:
1014 tobject = object;
1015 tpindex = pindex;
1016shadowlookup:
1017 /*
1018 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1019 * and those pages must be OBJ_ONEMAPPING.
1020 */
1021 if (advise == MADV_FREE) {
1022 if ((tobject->type != OBJT_DEFAULT &&
1023 tobject->type != OBJT_SWAP) ||
1024 (tobject->flags & OBJ_ONEMAPPING) == 0) {
1025 continue;
1026 }
1027 }
1028
1029 m = vm_page_lookup(tobject, tpindex);
1030
1031 if (m == NULL) {
1032 /*
1033 * There may be swap even if there is no backing page
1034 */
1035 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1036 swap_pager_freespace(tobject, tpindex, 1);
1037
1038 /*
1039 * next object
1040 */
1041 tobject = tobject->backing_object;
1042 if (tobject == NULL)
1043 continue;
1044 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1045 goto shadowlookup;
1046 }
1047
1048 /*
1049 * If the page is busy or not in a normal active state,
1050 * we skip it. If the page is not managed there are no
1051 * page queues to mess with. Things can break if we mess
1052 * with pages in any of the below states.
1053 */
1054 if (
1055 m->hold_count ||
1056 m->wire_count ||
1057 (m->flags & PG_UNMANAGED) ||
1058 m->valid != VM_PAGE_BITS_ALL
1059 ) {
1060 continue;
1061 }
1062
1063 if (vm_page_sleep_busy(m, TRUE, "madvpo"))
1064 goto relookup;
1065
1066 if (advise == MADV_WILLNEED) {
1067 vm_page_activate(m);
1068 } else if (advise == MADV_DONTNEED) {
1069 vm_page_dontneed(m);
1070 } else if (advise == MADV_FREE) {
1071 /*
1072 * Mark the page clean. This will allow the page
1073 * to be freed up by the system. However, such pages
1074 * are often reused quickly by malloc()/free()
1075 * so we do not do anything that would cause
1076 * a page fault if we can help it.
1077 *
1078 * Specifically, we do not try to actually free
1079 * the page now nor do we try to put it in the
1080 * cache (which would cause a page fault on reuse).
1081 *
1082 * But we do make the page is freeable as we
1083 * can without actually taking the step of unmapping
1084 * it.
1085 */
1086 pmap_clear_modify(m);
1087 m->dirty = 0;
1088 m->act_count = 0;
1089 vm_page_dontneed(m);
1090 if (tobject->type == OBJT_SWAP)
1091 swap_pager_freespace(tobject, tpindex, 1);
1092 }
1093 }
1094}
1095
1096/*
1097 * vm_object_shadow:
1098 *
1099 * Create a new object which is backed by the
1100 * specified existing object range. The source
1101 * object reference is deallocated.
1102 *
1103 * The new object and offset into that object
1104 * are returned in the source parameters.
1105 */
1106void
1107vm_object_shadow(
1108 vm_object_t *object, /* IN/OUT */
1109 vm_ooffset_t *offset, /* IN/OUT */
1110 vm_size_t length)
1111{
1112 vm_object_t source;
1113 vm_object_t result;
1114
1115 GIANT_REQUIRED;
1116 source = *object;
1117
1118 /*
1119 * Don't create the new object if the old object isn't shared.
1120 */
1121 if (source != NULL &&
1122 source->ref_count == 1 &&
1123 source->handle == NULL &&
1124 (source->type == OBJT_DEFAULT ||
1125 source->type == OBJT_SWAP))
1126 return;
1127
1128 /*
1129 * Allocate a new object with the given length
1130 */
1131 result = vm_object_allocate(OBJT_DEFAULT, length);
1132 KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing"));
1133
1134 /*
1135 * The new object shadows the source object, adding a reference to it.
1136 * Our caller changes his reference to point to the new object,
1137 * removing a reference to the source object. Net result: no change
1138 * of reference count.
1139 *
1140 * Try to optimize the result object's page color when shadowing
1141 * in order to maintain page coloring consistency in the combined
1142 * shadowed object.
1143 */
1144 result->backing_object = source;
1145 if (source) {
1146 TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list);
1147 source->shadow_count++;
1148 source->generation++;
1149 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1150 }
1151
1152 /*
1153 * Store the offset into the source object, and fix up the offset into
1154 * the new object.
1155 */
1156 result->backing_object_offset = *offset;
1157
1158 /*
1159 * Return the new things
1160 */
1161 *offset = 0;
1162 *object = result;
1163}
1164
1165#define OBSC_TEST_ALL_SHADOWED 0x0001
1166#define OBSC_COLLAPSE_NOWAIT 0x0002
1167#define OBSC_COLLAPSE_WAIT 0x0004
1168
1169static __inline int
1170vm_object_backing_scan(vm_object_t object, int op)
1171{
1172 int s;
1173 int r = 1;
1174 vm_page_t p;
1175 vm_object_t backing_object;
1176 vm_pindex_t backing_offset_index;
1177
1178 s = splvm();
1179 GIANT_REQUIRED;
1180
1181 backing_object = object->backing_object;
1182 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1183
1184 /*
1185 * Initial conditions
1186 */
1187 if (op & OBSC_TEST_ALL_SHADOWED) {
1188 /*
1189 * We do not want to have to test for the existence of
1190 * swap pages in the backing object. XXX but with the
1191 * new swapper this would be pretty easy to do.
1192 *
1193 * XXX what about anonymous MAP_SHARED memory that hasn't
1194 * been ZFOD faulted yet? If we do not test for this, the
1195 * shadow test may succeed! XXX
1196 */
1197 if (backing_object->type != OBJT_DEFAULT) {
1198 splx(s);
1199 return (0);
1200 }
1201 }
1202 if (op & OBSC_COLLAPSE_WAIT) {
1203 vm_object_set_flag(backing_object, OBJ_DEAD);
1204 }
1205
1206 /*
1207 * Our scan
1208 */
1209 p = TAILQ_FIRST(&backing_object->memq);
1210 while (p) {
1211 vm_page_t next = TAILQ_NEXT(p, listq);
1212 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1213
1214 if (op & OBSC_TEST_ALL_SHADOWED) {
1215 vm_page_t pp;
1216
1217 /*
1218 * Ignore pages outside the parent object's range
1219 * and outside the parent object's mapping of the
1220 * backing object.
1221 *
1222 * note that we do not busy the backing object's
1223 * page.
1224 */
1225 if (
1226 p->pindex < backing_offset_index ||
1227 new_pindex >= object->size
1228 ) {
1229 p = next;
1230 continue;
1231 }
1232
1233 /*
1234 * See if the parent has the page or if the parent's
1235 * object pager has the page. If the parent has the
1236 * page but the page is not valid, the parent's
1237 * object pager must have the page.
1238 *
1239 * If this fails, the parent does not completely shadow
1240 * the object and we might as well give up now.
1241 */
1242
1243 pp = vm_page_lookup(object, new_pindex);
1244 if (
1245 (pp == NULL || pp->valid == 0) &&
1246 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1247 ) {
1248 r = 0;
1249 break;
1250 }
1251 }
1252
1253 /*
1254 * Check for busy page
1255 */
1256 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1257 vm_page_t pp;
1258
1259 if (op & OBSC_COLLAPSE_NOWAIT) {
1260 if (
1261 (p->flags & PG_BUSY) ||
1262 !p->valid ||
1263 p->hold_count ||
1264 p->wire_count ||
1265 p->busy
1266 ) {
1267 p = next;
1268 continue;
1269 }
1270 } else if (op & OBSC_COLLAPSE_WAIT) {
1271 if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1272 /*
1273 * If we slept, anything could have
1274 * happened. Since the object is
1275 * marked dead, the backing offset
1276 * should not have changed so we
1277 * just restart our scan.
1278 */
1279 p = TAILQ_FIRST(&backing_object->memq);
1280 continue;
1281 }
1282 }
1283
1284 /*
1285 * Busy the page
1286 */
1287 vm_page_busy(p);
1288
1289 KASSERT(
1290 p->object == backing_object,
1291 ("vm_object_qcollapse(): object mismatch")
1292 );
1293
1294 /*
1295 * Destroy any associated swap
1296 */
1297 if (backing_object->type == OBJT_SWAP) {
1298 swap_pager_freespace(
1299 backing_object,
1300 p->pindex,
1301 1
1302 );
1303 }
1304
1305 if (
1306 p->pindex < backing_offset_index ||
1307 new_pindex >= object->size
1308 ) {
1309 /*
1310 * Page is out of the parent object's range, we
1311 * can simply destroy it.
1312 */
1313 vm_page_protect(p, VM_PROT_NONE);
1314 vm_page_free(p);
1315 p = next;
1316 continue;
1317 }
1318
1319 pp = vm_page_lookup(object, new_pindex);
1320 if (
1321 pp != NULL ||
1322 vm_pager_has_page(object, new_pindex, NULL, NULL)
1323 ) {
1324 /*
1325 * page already exists in parent OR swap exists
1326 * for this location in the parent. Destroy
1327 * the original page from the backing object.
1328 *
1329 * Leave the parent's page alone
1330 */
1331 vm_page_protect(p, VM_PROT_NONE);
1332 vm_page_free(p);
1333 p = next;
1334 continue;
1335 }
1336
1337 /*
1338 * Page does not exist in parent, rename the
1339 * page from the backing object to the main object.
1340 *
1341 * If the page was mapped to a process, it can remain
1342 * mapped through the rename.
1343 */
1344 if ((p->queue - p->pc) == PQ_CACHE)
1345 vm_page_deactivate(p);
1346
1347 vm_page_rename(p, object, new_pindex);
1348 /* page automatically made dirty by rename */
1349 }
1350 p = next;
1351 }
1352 splx(s);
1353 return (r);
1354}
1355
1356
1357/*
1358 * this version of collapse allows the operation to occur earlier and
1359 * when paging_in_progress is true for an object... This is not a complete
1360 * operation, but should plug 99.9% of the rest of the leaks.
1361 */
1362static void
1363vm_object_qcollapse(vm_object_t object)
1364{
1365 vm_object_t backing_object = object->backing_object;
1366
1367 GIANT_REQUIRED;
1368
1369 if (backing_object->ref_count != 1)
1370 return;
1371
1372 backing_object->ref_count += 2;
1373
1374 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1375
1376 backing_object->ref_count -= 2;
1377}
1378
1379/*
1380 * vm_object_collapse:
1381 *
1382 * Collapse an object with the object backing it.
1383 * Pages in the backing object are moved into the
1384 * parent, and the backing object is deallocated.
1385 */
1386void
1387vm_object_collapse(vm_object_t object)
1388{
1389 GIANT_REQUIRED;
1390
1391 while (TRUE) {
1392 vm_object_t backing_object;
1393
1394 /*
1395 * Verify that the conditions are right for collapse:
1396 *
1397 * The object exists and the backing object exists.
1398 */
1399 if (object == NULL)
1400 break;
1401
1402 if ((backing_object = object->backing_object) == NULL)
1403 break;
1404
1405 /*
1406 * we check the backing object first, because it is most likely
1407 * not collapsable.
1408 */
1409 if (backing_object->handle != NULL ||
1410 (backing_object->type != OBJT_DEFAULT &&
1411 backing_object->type != OBJT_SWAP) ||
1412 (backing_object->flags & OBJ_DEAD) ||
1413 object->handle != NULL ||
1414 (object->type != OBJT_DEFAULT &&
1415 object->type != OBJT_SWAP) ||
1416 (object->flags & OBJ_DEAD)) {
1417 break;
1418 }
1419
1420 if (
1421 object->paging_in_progress != 0 ||
1422 backing_object->paging_in_progress != 0
1423 ) {
1424 vm_object_qcollapse(object);
1425 break;
1426 }
1427
1428 /*
1429 * We know that we can either collapse the backing object (if
1430 * the parent is the only reference to it) or (perhaps) have
1431 * the parent bypass the object if the parent happens to shadow
1432 * all the resident pages in the entire backing object.
1433 *
1434 * This is ignoring pager-backed pages such as swap pages.
1435 * vm_object_backing_scan fails the shadowing test in this
1436 * case.
1437 */
1438 if (backing_object->ref_count == 1) {
1439 /*
1440 * If there is exactly one reference to the backing
1441 * object, we can collapse it into the parent.
1442 */
1443 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1444
1445 /*
1446 * Move the pager from backing_object to object.
1447 */
1448 if (backing_object->type == OBJT_SWAP) {
1449 vm_object_pip_add(backing_object, 1);
1450
1451 /*
1452 * scrap the paging_offset junk and do a
1453 * discrete copy. This also removes major
1454 * assumptions about how the swap-pager
1455 * works from where it doesn't belong. The
1456 * new swapper is able to optimize the
1457 * destroy-source case.
1458 */
1459 vm_object_pip_add(object, 1);
1460 swap_pager_copy(
1461 backing_object,
1462 object,
1463 OFF_TO_IDX(object->backing_object_offset), TRUE);
1464 vm_object_pip_wakeup(object);
1465
1466 vm_object_pip_wakeup(backing_object);
1467 }
1468 /*
1469 * Object now shadows whatever backing_object did.
1470 * Note that the reference to
1471 * backing_object->backing_object moves from within
1472 * backing_object to within object.
1473 */
1474 TAILQ_REMOVE(
1475 &object->backing_object->shadow_head,
1476 object,
1477 shadow_list
1478 );
1479 object->backing_object->shadow_count--;
1480 object->backing_object->generation++;
1481 if (backing_object->backing_object) {
1482 TAILQ_REMOVE(
1483 &backing_object->backing_object->shadow_head,
1484 backing_object,
1485 shadow_list
1486 );
1487 backing_object->backing_object->shadow_count--;
1488 backing_object->backing_object->generation++;
1489 }
1490 object->backing_object = backing_object->backing_object;
1491 if (object->backing_object) {
1492 TAILQ_INSERT_TAIL(
1493 &object->backing_object->shadow_head,
1494 object,
1495 shadow_list
1496 );
1497 object->backing_object->shadow_count++;
1498 object->backing_object->generation++;
1499 }
1500
1501 object->backing_object_offset +=
1502 backing_object->backing_object_offset;
1503
1504 /*
1505 * Discard backing_object.
1506 *
1507 * Since the backing object has no pages, no pager left,
1508 * and no object references within it, all that is
1509 * necessary is to dispose of it.
1510 */
1511 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1512 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
1513
1514 TAILQ_REMOVE(
1515 &vm_object_list,
1516 backing_object,
1517 object_list
1518 );
1519
1520 zfree(obj_zone, backing_object);
1521
1522 object_collapses++;
1523 } else {
1524 vm_object_t new_backing_object;
1525
1526 /*
1527 * If we do not entirely shadow the backing object,
1528 * there is nothing we can do so we give up.
1529 */
1530 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1531 break;
1532 }
1533
1534 /*
1535 * Make the parent shadow the next object in the
1536 * chain. Deallocating backing_object will not remove
1537 * it, since its reference count is at least 2.
1538 */
1539 TAILQ_REMOVE(
1540 &backing_object->shadow_head,
1541 object,
1542 shadow_list
1543 );
1544 backing_object->shadow_count--;
1545 backing_object->generation++;
1546
1547 new_backing_object = backing_object->backing_object;
1548 if ((object->backing_object = new_backing_object) != NULL) {
1549 vm_object_reference(new_backing_object);
1550 TAILQ_INSERT_TAIL(
1551 &new_backing_object->shadow_head,
1552 object,
1553 shadow_list
1554 );
1555 new_backing_object->shadow_count++;
1556 new_backing_object->generation++;
1557 object->backing_object_offset +=
1558 backing_object->backing_object_offset;
1559 }
1560
1561 /*
1562 * Drop the reference count on backing_object. Since
1563 * its ref_count was at least 2, it will not vanish;
1564 * so we don't need to call vm_object_deallocate, but
1565 * we do anyway.
1566 */
1567 vm_object_deallocate(backing_object);
1568 object_bypasses++;
1569 }
1570
1571 /*
1572 * Try again with this object's new backing object.
1573 */
1574 }
1575}
1576
1577/*
1578 * vm_object_page_remove: [internal]
1579 *
1580 * Removes all physical pages in the specified
1581 * object range from the object's list of pages.
1582 *
1583 * The object must be locked.
1584 */
1585void
1586vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, boolean_t clean_only)
1587{
1588 vm_page_t p, next;
1589 unsigned int size;
1590 int all;
1591
1592 GIANT_REQUIRED;
1593
1594 if (object == NULL ||
1595 object->resident_page_count == 0)
1596 return;
1597
1598 all = ((end == 0) && (start == 0));
1599
1600 /*
1601 * Since physically-backed objects do not use managed pages, we can't
1602 * remove pages from the object (we must instead remove the page
1603 * references, and then destroy the object).
1604 */
1605 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object"));
1606
1607 vm_object_pip_add(object, 1);
1608again:
1609 size = end - start;
1610 if (all || size > object->resident_page_count / 4) {
1611 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
1612 next = TAILQ_NEXT(p, listq);
1613 if (all || ((start <= p->pindex) && (p->pindex < end))) {
1614 if (p->wire_count != 0) {
1615 vm_page_protect(p, VM_PROT_NONE);
1616 if (!clean_only)
1617 p->valid = 0;
1618 continue;
1619 }
1620
1621 /*
1622 * The busy flags are only cleared at
1623 * interrupt -- minimize the spl transitions
1624 */
1625 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1626 goto again;
1627
1628 if (clean_only && p->valid) {
1629 vm_page_test_dirty(p);
1630 if (p->valid & p->dirty)
1631 continue;
1632 }
1633
1634 vm_page_busy(p);
1635 vm_page_protect(p, VM_PROT_NONE);
1636 vm_page_free(p);
1637 }
1638 }
1639 } else {
1640 while (size > 0) {
1641 if ((p = vm_page_lookup(object, start)) != 0) {
1642
1643 if (p->wire_count != 0) {
1644 vm_page_protect(p, VM_PROT_NONE);
1645 if (!clean_only)
1646 p->valid = 0;
1647 start += 1;
1648 size -= 1;
1649 continue;
1650 }
1651
1652 /*
1653 * The busy flags are only cleared at
1654 * interrupt -- minimize the spl transitions
1655 */
1656 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1657 goto again;
1658
1659 if (clean_only && p->valid) {
1660 vm_page_test_dirty(p);
1661 if (p->valid & p->dirty) {
1662 start += 1;
1663 size -= 1;
1664 continue;
1665 }
1666 }
1667
1668 vm_page_busy(p);
1669 vm_page_protect(p, VM_PROT_NONE);
1670 vm_page_free(p);
1671 }
1672 start += 1;
1673 size -= 1;
1674 }
1675 }
1676 vm_object_pip_wakeup(object);
1677}
1678
1679/*
1680 * Routine: vm_object_coalesce
1681 * Function: Coalesces two objects backing up adjoining
1682 * regions of memory into a single object.
1683 *
1684 * returns TRUE if objects were combined.
1685 *
1686 * NOTE: Only works at the moment if the second object is NULL -
1687 * if it's not, which object do we lock first?
1688 *
1689 * Parameters:
1690 * prev_object First object to coalesce
1691 * prev_offset Offset into prev_object
1692 * next_object Second object into coalesce
1693 * next_offset Offset into next_object
1694 *
1695 * prev_size Size of reference to prev_object
1696 * next_size Size of reference to next_object
1697 *
1698 * Conditions:
1699 * The object must *not* be locked.
1700 */
1701boolean_t
1702vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size)
1703{
1704 vm_pindex_t next_pindex;
1705
1706 GIANT_REQUIRED;
1707
1708 if (prev_object == NULL) {
1709 return (TRUE);
1710 }
1711
1712 if (prev_object->type != OBJT_DEFAULT &&
1713 prev_object->type != OBJT_SWAP) {
1714 return (FALSE);
1715 }
1716
1717 /*
1718 * Try to collapse the object first
1719 */
1720 vm_object_collapse(prev_object);
1721
1722 /*
1723 * Can't coalesce if: . more than one reference . paged out . shadows
1724 * another object . has a copy elsewhere (any of which mean that the
1725 * pages not mapped to prev_entry may be in use anyway)
1726 */
1727 if (prev_object->backing_object != NULL) {
1728 return (FALSE);
1729 }
1730
1731 prev_size >>= PAGE_SHIFT;
1732 next_size >>= PAGE_SHIFT;
1733 next_pindex = prev_pindex + prev_size;
1734
1735 if ((prev_object->ref_count > 1) &&
1736 (prev_object->size != next_pindex)) {
1737 return (FALSE);
1738 }
1739
1740 /*
1741 * Remove any pages that may still be in the object from a previous
1742 * deallocation.
1743 */
1744 if (next_pindex < prev_object->size) {
1745 vm_object_page_remove(prev_object,
1746 next_pindex,
1747 next_pindex + next_size, FALSE);
1748 if (prev_object->type == OBJT_SWAP)
1749 swap_pager_freespace(prev_object,
1750 next_pindex, next_size);
1751 }
1752
1753 /*
1754 * Extend the object if necessary.
1755 */
1756 if (next_pindex + next_size > prev_object->size)
1757 prev_object->size = next_pindex + next_size;
1758
1759 return (TRUE);
1760}
1761
1762void
1763vm_object_set_writeable_dirty(vm_object_t object)
1764{
1765 struct vnode *vp;
1766
1767 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1768 if (object->type == OBJT_VNODE &&
1769 (vp = (struct vnode *)object->handle) != NULL) {
1770 if ((vp->v_flag & VOBJDIRTY) == 0) {
1771 mtx_lock(&vp->v_interlock);
1772 vp->v_flag |= VOBJDIRTY;
1773 mtx_unlock(&vp->v_interlock);
1774 }
1775 }
1776}
1777
1778#include "opt_ddb.h"
1779#ifdef DDB
1780#include <sys/kernel.h>
1781
1782#include <sys/cons.h>
1783
1784#include <ddb/ddb.h>
1785
1786static int
1787_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1788{
1789 vm_map_t tmpm;
1790 vm_map_entry_t tmpe;
1791 vm_object_t obj;
1792 int entcount;
1793
1794 if (map == 0)
1795 return 0;
1796
1797 if (entry == 0) {
1798 tmpe = map->header.next;
1799 entcount = map->nentries;
1800 while (entcount-- && (tmpe != &map->header)) {
1801 if (_vm_object_in_map(map, object, tmpe)) {
1802 return 1;
1803 }
1804 tmpe = tmpe->next;
1805 }
1806 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1807 tmpm = entry->object.sub_map;
1808 tmpe = tmpm->header.next;
1809 entcount = tmpm->nentries;
1810 while (entcount-- && tmpe != &tmpm->header) {
1811 if (_vm_object_in_map(tmpm, object, tmpe)) {
1812 return 1;
1813 }
1814 tmpe = tmpe->next;
1815 }
1816 } else if ((obj = entry->object.vm_object) != NULL) {
1817 for (; obj; obj = obj->backing_object)
1818 if (obj == object) {
1819 return 1;
1820 }
1821 }
1822 return 0;
1823}
1824
1825static int
1826vm_object_in_map(vm_object_t object)
1827{
1828 struct proc *p;
1829
1830 /* sx_slock(&allproc_lock); */
1831 LIST_FOREACH(p, &allproc, p_list) {
1832 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1833 continue;
1834 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1835 /* sx_sunlock(&allproc_lock); */
1836 return 1;
1837 }
1838 }
1839 /* sx_sunlock(&allproc_lock); */
1840 if (_vm_object_in_map(kernel_map, object, 0))
1841 return 1;
1842 if (_vm_object_in_map(kmem_map, object, 0))
1843 return 1;
1844 if (_vm_object_in_map(pager_map, object, 0))
1845 return 1;
1846 if (_vm_object_in_map(buffer_map, object, 0))
1847 return 1;
1848 return 0;
1849}
1850
1851DB_SHOW_COMMAND(vmochk, vm_object_check)
1852{
1853 vm_object_t object;
1854
1855 /*
1856 * make sure that internal objs are in a map somewhere
1857 * and none have zero ref counts.
1858 */
1859 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1860 if (object->handle == NULL &&
1861 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
1862 if (object->ref_count == 0) {
1863 db_printf("vmochk: internal obj has zero ref count: %ld\n",
1864 (long)object->size);
1865 }
1866 if (!vm_object_in_map(object)) {
1867 db_printf(
1868 "vmochk: internal obj is not in a map: "
1869 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
1870 object->ref_count, (u_long)object->size,
1871 (u_long)object->size,
1872 (void *)object->backing_object);
1873 }
1874 }
1875 }
1876}
1877
1878/*
1879 * vm_object_print: [ debug ]
1880 */
1881DB_SHOW_COMMAND(object, vm_object_print_static)
1882{
1883 /* XXX convert args. */
1884 vm_object_t object = (vm_object_t)addr;
1885 boolean_t full = have_addr;
1886
1887 vm_page_t p;
1888
1889 /* XXX count is an (unused) arg. Avoid shadowing it. */
1890#define count was_count
1891
1892 int count;
1893
1894 if (object == NULL)
1895 return;
1896
1897 db_iprintf(
1898 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
1899 object, (int)object->type, (u_long)object->size,
1900 object->resident_page_count, object->ref_count, object->flags);
1901 /*
1902 * XXX no %qd in kernel. Truncate object->backing_object_offset.
1903 */
1904 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
1905 object->shadow_count,
1906 object->backing_object ? object->backing_object->ref_count : 0,
1907 object->backing_object, (long)object->backing_object_offset);
1908
1909 if (!full)
1910 return;
1911
1912 db_indent += 2;
1913 count = 0;
1914 TAILQ_FOREACH(p, &object->memq, listq) {
1915 if (count == 0)
1916 db_iprintf("memory:=");
1917 else if (count == 6) {
1918 db_printf("\n");
1919 db_iprintf(" ...");
1920 count = 0;
1921 } else
1922 db_printf(",");
1923 count++;
1924
1925 db_printf("(off=0x%lx,page=0x%lx)",
1926 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
1927 }
1928 if (count != 0)
1929 db_printf("\n");
1930 db_indent -= 2;
1931}
1932
1933/* XXX. */
1934#undef count
1935
1936/* XXX need this non-static entry for calling from vm_map_print. */
1937void
1938vm_object_print(
1939 /* db_expr_t */ long addr,
1940 boolean_t have_addr,
1941 /* db_expr_t */ long count,
1942 char *modif)
1943{
1944 vm_object_print_static(addr, have_addr, count, modif);
1945}
1946
1947DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
1948{
1949 vm_object_t object;
1950 int nl = 0;
1951 int c;
1952
1953 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1954 vm_pindex_t idx, fidx;
1955 vm_pindex_t osize;
1956 vm_offset_t pa = -1, padiff;
1957 int rcount;
1958 vm_page_t m;
1959
1960 db_printf("new object: %p\n", (void *)object);
1961 if (nl > 18) {
1962 c = cngetc();
1963 if (c != ' ')
1964 return;
1965 nl = 0;
1966 }
1967 nl++;
1968 rcount = 0;
1969 fidx = 0;
1970 osize = object->size;
1971 if (osize > 128)
1972 osize = 128;
1973 for (idx = 0; idx < osize; idx++) {
1974 m = vm_page_lookup(object, idx);
1975 if (m == NULL) {
1976 if (rcount) {
1977 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1978 (long)fidx, rcount, (long)pa);
1979 if (nl > 18) {
1980 c = cngetc();
1981 if (c != ' ')
1982 return;
1983 nl = 0;
1984 }
1985 nl++;
1986 rcount = 0;
1987 }
1988 continue;
1989 }
1990
1991
1992 if (rcount &&
1993 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
1994 ++rcount;
1995 continue;
1996 }
1997 if (rcount) {
1998 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
1999 padiff >>= PAGE_SHIFT;
2000 padiff &= PQ_L2_MASK;
2001 if (padiff == 0) {
2002 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
2003 ++rcount;
2004 continue;
2005 }
2006 db_printf(" index(%ld)run(%d)pa(0x%lx)",
2007 (long)fidx, rcount, (long)pa);
2008 db_printf("pd(%ld)\n", (long)padiff);
2009 if (nl > 18) {
2010 c = cngetc();
2011 if (c != ' ')
2012 return;
2013 nl = 0;
2014 }
2015 nl++;
2016 }
2017 fidx = idx;
2018 pa = VM_PAGE_TO_PHYS(m);
2019 rcount = 1;
2020 }
2021 if (rcount) {
2022 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2023 (long)fidx, rcount, (long)pa);
2024 if (nl > 18) {
2025 c = cngetc();
2026 if (c != ' ')
2027 return;
2028 nl = 0;
2029 }
2030 nl++;
2031 }
2032 }
2033}
2034#endif /* DDB */