ae9aee5d00e5a474b4404751875262fae01d9fcb
[dragonfly.git] / sys / vm / vm_object.c
1 /*
2  * (MPSAFE)
3  *
4  * Copyright (c) 1991, 1993
5  *      The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * The Mach Operating System project at Carnegie-Mellon University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the University of
21  *      California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *      from: @(#)vm_object.c   8.5 (Berkeley) 3/22/94
39  *
40  *
41  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42  * All rights reserved.
43  *
44  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
45  *
46  * Permission to use, copy, modify and distribute this software and
47  * its documentation is hereby granted, provided that both the copyright
48  * notice and this permission notice appear in all copies of the
49  * software, derivative works or modified versions, and any portions
50  * thereof, and that both notices appear in supporting documentation.
51  *
52  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
55  *
56  * Carnegie Mellon requests users of this software to return to
57  *
58  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
59  *  School of Computer Science
60  *  Carnegie Mellon University
61  *  Pittsburgh PA 15213-3890
62  *
63  * any improvements or extensions that they make and grant Carnegie the
64  * rights to redistribute these changes.
65  *
66  * $FreeBSD: src/sys/vm/vm_object.c,v 1.171.2.8 2003/05/26 19:17:56 alc Exp $
67  */
68
69 /*
70  *      Virtual memory object module.
71  */
72
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/proc.h>           /* for curproc, pageproc */
76 #include <sys/thread.h>
77 #include <sys/vnode.h>
78 #include <sys/vmmeter.h>
79 #include <sys/mman.h>
80 #include <sys/mount.h>
81 #include <sys/kernel.h>
82 #include <sys/sysctl.h>
83 #include <sys/refcount.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/swap_pager.h>
94 #include <vm/vm_kern.h>
95 #include <vm/vm_extern.h>
96 #include <vm/vm_zone.h>
97
98 #define EASY_SCAN_FACTOR        8
99
100 static void     vm_object_qcollapse(vm_object_t object);
101 static int      vm_object_page_collect_flush(vm_object_t object, vm_page_t p,
102                                              int pagerflags);
103 static void     vm_object_lock_init(vm_object_t);
104 static void     vm_object_hold_wait(vm_object_t);
105
106
107 /*
108  *      Virtual memory objects maintain the actual data
109  *      associated with allocated virtual memory.  A given
110  *      page of memory exists within exactly one object.
111  *
112  *      An object is only deallocated when all "references"
113  *      are given up.  Only one "reference" to a given
114  *      region of an object should be writeable.
115  *
116  *      Associated with each object is a list of all resident
117  *      memory pages belonging to that object; this list is
118  *      maintained by the "vm_page" module, and locked by the object's
119  *      lock.
120  *
121  *      Each object also records a "pager" routine which is
122  *      used to retrieve (and store) pages to the proper backing
123  *      storage.  In addition, objects may be backed by other
124  *      objects from which they were virtual-copied.
125  *
126  *      The only items within the object structure which are
127  *      modified after time of creation are:
128  *              reference count         locked by object's lock
129  *              pager routine           locked by object's lock
130  *
131  */
132
133 struct object_q vm_object_list;         /* locked by vmobj_token */
134 struct vm_object kernel_object;
135
136 static long vm_object_count;            /* locked by vmobj_token */
137 extern int vm_pageout_page_count;
138
139 static long object_collapses;
140 static long object_bypasses;
141 static int next_index;
142 static vm_zone_t obj_zone;
143 static struct vm_zone obj_zone_store;
144 #define VM_OBJECTS_INIT 256
145 static struct vm_object vm_objects_init[VM_OBJECTS_INIT];
146
147 /*
148  * Misc low level routines
149  */
150 static void
151 vm_object_lock_init(vm_object_t obj)
152 {
153 #if defined(DEBUG_LOCKS)
154         int i;
155
156         obj->debug_hold_bitmap = 0;
157         obj->debug_hold_ovfl = 0;
158         for (i = 0; i < VMOBJ_DEBUG_ARRAY_SIZE; i++) {
159                 obj->debug_hold_thrs[i] = NULL;
160                 obj->debug_hold_file[i] = NULL;
161                 obj->debug_hold_line[i] = 0;
162         }
163 #endif
164 }
165
166 void
167 vm_object_lock_swap(void)
168 {
169         lwkt_token_swap();
170 }
171
172 void
173 vm_object_lock(vm_object_t obj)
174 {
175         lwkt_getpooltoken(obj);
176 }
177
178 void
179 vm_object_unlock(vm_object_t obj)
180 {
181         lwkt_relpooltoken(obj);
182 }
183
184 static __inline void
185 vm_object_assert_held(vm_object_t obj)
186 {
187         ASSERT_LWKT_TOKEN_HELD(lwkt_token_pool_lookup(obj));
188 }
189
190 void
191 #ifndef DEBUG_LOCKS
192 vm_object_hold(vm_object_t obj)
193 #else
194 debugvm_object_hold(vm_object_t obj, char *file, int line)
195 #endif
196 {
197         if (obj == NULL)
198                 return;
199
200         /*
201          * Object must be held (object allocation is stable due to callers
202          * context, typically already holding the token on a parent object)
203          * prior to potentially blocking on the lock, otherwise the object
204          * can get ripped away from us.
205          */
206         refcount_acquire(&obj->hold_count);
207         vm_object_lock(obj);
208
209 #if defined(DEBUG_LOCKS)
210         int i;
211
212         i = ffs(~obj->debug_hold_bitmap) - 1;
213         if (i == -1) {
214                 kprintf("vm_object hold count > VMOBJ_DEBUG_ARRAY_SIZE");
215                 obj->debug_hold_ovfl = 1;
216         }
217
218         obj->debug_hold_bitmap |= (1 << i);
219         obj->debug_hold_thrs[i] = curthread;
220         obj->debug_hold_file[i] = file;
221         obj->debug_hold_line[i] = line;
222 #endif
223 }
224
225 void
226 vm_object_drop(vm_object_t obj)
227 {
228         if (obj == NULL)
229                 return;
230
231 #if defined(DEBUG_LOCKS)
232         int found = 0;
233         int i;
234
235         for (i = 0; i < VMOBJ_DEBUG_ARRAY_SIZE; i++) {
236                 if ((obj->debug_hold_bitmap & (1 << i)) &&
237                     (obj->debug_hold_thrs[i] == curthread)) {
238                         obj->debug_hold_bitmap &= ~(1 << i);
239                         obj->debug_hold_thrs[i] = NULL;
240                         obj->debug_hold_file[i] = NULL;
241                         obj->debug_hold_line[i] = 0;
242                         found = 1;
243                         break;
244                 }
245         }
246
247         if (found == 0 && obj->debug_hold_ovfl == 0)
248                 panic("vm_object: attempt to drop hold on non-self-held obj");
249 #endif
250
251         /*
252          * The lock is a pool token, keep holding it across potential
253          * wakeups to interlock the tsleep/wakeup.
254          */
255         if (refcount_release(&obj->hold_count))
256                 wakeup(obj);
257         vm_object_unlock(obj);
258 }
259
260 /*
261  * This can only be called while the caller holds the object
262  * with the OBJ_DEAD interlock.  Since there are no refs this
263  * is the only thing preventing an object destruction race.
264  */
265 static void
266 vm_object_hold_wait(vm_object_t obj)
267 {
268         vm_object_lock(obj);
269
270 #if defined(DEBUG_LOCKS)
271         int i;
272
273         for (i = 0; i < VMOBJ_DEBUG_ARRAY_SIZE; i++) {
274                 if ((obj->debug_hold_bitmap & (1 << i)) &&
275                     (obj->debug_hold_thrs[i] == curthread))  {
276                         kprintf("vm_object %p: self-hold in at %s:%d\n", obj,
277                                 obj->debug_hold_file[i], obj->debug_hold_line[i]);
278                         panic("vm_object: self-hold in terminate or collapse");
279                 }
280         }
281 #endif
282
283         while (obj->hold_count)
284                 tsleep(obj, 0, "vmobjhld", 0);
285
286         vm_object_unlock(obj);
287 }
288
289
290 /*
291  * Initialize a freshly allocated object
292  *
293  * Used only by vm_object_allocate() and zinitna().
294  *
295  * No requirements.
296  */
297 void
298 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object)
299 {
300         int incr;
301
302         RB_INIT(&object->rb_memq);
303         LIST_INIT(&object->shadow_head);
304
305         object->type = type;
306         object->size = size;
307         object->ref_count = 1;
308         object->hold_count = 0;
309         object->flags = 0;
310         if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
311                 vm_object_set_flag(object, OBJ_ONEMAPPING);
312         object->paging_in_progress = 0;
313         object->resident_page_count = 0;
314         object->agg_pv_list_count = 0;
315         object->shadow_count = 0;
316         object->pg_color = next_index;
317         if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
318                 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
319         else
320                 incr = size;
321         next_index = (next_index + incr) & PQ_L2_MASK;
322         object->handle = NULL;
323         object->backing_object = NULL;
324         object->backing_object_offset = (vm_ooffset_t) 0;
325
326         object->generation++;
327         object->swblock_count = 0;
328         RB_INIT(&object->swblock_root);
329         vm_object_lock_init(object);
330
331         lwkt_gettoken(&vmobj_token);
332         TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
333         vm_object_count++;
334         lwkt_reltoken(&vmobj_token);
335 }
336
337 /*
338  * Initialize the VM objects module.
339  *
340  * Called from the low level boot code only.
341  */
342 void
343 vm_object_init(void)
344 {
345         TAILQ_INIT(&vm_object_list);
346         
347         _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(KvaEnd),
348                             &kernel_object);
349
350         obj_zone = &obj_zone_store;
351         zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object),
352                 vm_objects_init, VM_OBJECTS_INIT);
353 }
354
355 void
356 vm_object_init2(void)
357 {
358         zinitna(obj_zone, NULL, NULL, 0, 0, ZONE_PANICFAIL, 1);
359 }
360
361 /*
362  * Allocate and return a new object of the specified type and size.
363  *
364  * No requirements.
365  */
366 vm_object_t
367 vm_object_allocate(objtype_t type, vm_pindex_t size)
368 {
369         vm_object_t result;
370
371         result = (vm_object_t) zalloc(obj_zone);
372
373         _vm_object_allocate(type, size, result);
374
375         return (result);
376 }
377
378 /*
379  * Add an additional reference to a vm_object.
380  *
381  * Object passed by caller must be stable or caller must already
382  * hold vmobj_token to avoid races.
383  */
384 void
385 vm_object_reference(vm_object_t object)
386 {
387         lwkt_gettoken(&vmobj_token);
388         vm_object_hold(object);
389         vm_object_reference_locked(object);
390         vm_object_drop(object);
391         lwkt_reltoken(&vmobj_token);
392 }
393
394 void
395 vm_object_reference_locked(vm_object_t object)
396 {
397         if (object) {
398                 ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
399                 /*NOTYET*/
400                 /*ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));*/
401                 object->ref_count++;
402                 if (object->type == OBJT_VNODE) {
403                         vref(object->handle);
404                         /* XXX what if the vnode is being destroyed? */
405                 }
406         }
407 }
408
409 /*
410  * Dereference an object and its underlying vnode.
411  *
412  * The caller must hold vmobj_token.
413  * The object must be locked but not held.  This function will eat the lock.
414  */
415 static void
416 vm_object_vndeallocate(vm_object_t object)
417 {
418         struct vnode *vp = (struct vnode *) object->handle;
419
420         KASSERT(object->type == OBJT_VNODE,
421             ("vm_object_vndeallocate: not a vnode object"));
422         KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
423         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
424 #ifdef INVARIANTS
425         if (object->ref_count == 0) {
426                 vprint("vm_object_vndeallocate", vp);
427                 panic("vm_object_vndeallocate: bad object reference count");
428         }
429 #endif
430
431         object->ref_count--;
432         if (object->ref_count == 0)
433                 vclrflags(vp, VTEXT);
434         vm_object_unlock(object);
435         vrele(vp);
436 }
437
438 /*
439  * Release a reference to the specified object, gained either through a
440  * vm_object_allocate or a vm_object_reference call.  When all references
441  * are gone, storage associated with this object may be relinquished.
442  *
443  * The caller does not have to hold the object locked but must have control
444  * over the reference in question in order to guarantee that the object
445  * does not get ripped out from under us.
446  */
447 void
448 vm_object_deallocate(vm_object_t object)
449 {
450         lwkt_gettoken(&vmobj_token);
451         vm_object_deallocate_locked(object);
452         lwkt_reltoken(&vmobj_token);
453 }
454
455 void
456 vm_object_deallocate_locked(vm_object_t object)
457 {
458         vm_object_t temp;
459
460         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
461
462         if (object)
463                 vm_object_lock(object);
464
465         while (object != NULL) {
466                 if (object->type == OBJT_VNODE) {
467                         vm_object_vndeallocate(object);
468                         /* vndeallocate ate the lock */
469                         break;
470                 }
471
472                 if (object->ref_count == 0) {
473                         panic("vm_object_deallocate: object deallocated "
474                               "too many times: %d", object->type);
475                 }
476                 if (object->ref_count > 2) {
477                         object->ref_count--;
478                         vm_object_unlock(object);
479                         break;
480                 }
481
482                 /*
483                  * We currently need the vm_token from this point on, and
484                  * we must recheck ref_count after acquiring it.
485                  */
486                 lwkt_gettoken(&vm_token);
487
488                 if (object->ref_count > 2) {
489                         object->ref_count--;
490                         lwkt_reltoken(&vm_token);
491                         vm_object_unlock(object);
492                         break;
493                 }
494
495                 /*
496                  * Here on ref_count of one or two, which are special cases for
497                  * objects.
498                  *
499                  * Nominal ref_count > 1 case if the second ref is not from
500                  * a shadow.
501                  */
502                 if (object->ref_count == 2 && object->shadow_count == 0) {
503                         vm_object_set_flag(object, OBJ_ONEMAPPING);
504                         object->ref_count--;
505                         lwkt_reltoken(&vm_token);
506                         vm_object_unlock(object);
507                         break;
508                 }
509
510                 /*
511                  * If the second ref is from a shadow we chain along it
512                  * if object's handle is exhausted.
513                  *
514                  * We have to decrement object->ref_count before potentially
515                  * collapsing the first shadow object or the collapse code
516                  * will not be able to handle the degenerate case.
517                  */
518                 if (object->ref_count == 2 && object->shadow_count == 1) {
519                         object->ref_count--;
520                         if (object->handle == NULL &&
521                             (object->type == OBJT_DEFAULT ||
522                              object->type == OBJT_SWAP)) {
523                                 temp = LIST_FIRST(&object->shadow_head);
524                                 KASSERT(temp != NULL,
525                                         ("vm_object_deallocate: ref_count: "
526                                         "%d, shadow_count: %d",
527                                         object->ref_count,
528                                         object->shadow_count));
529                                 lwkt_reltoken(&vm_token);
530                                 vm_object_lock(temp);
531
532                                 if ((temp->handle == NULL) &&
533                                     (temp->type == OBJT_DEFAULT ||
534                                      temp->type == OBJT_SWAP)) {
535                                         /*
536                                          * Special case, must handle ref_count
537                                          * manually to avoid recursion.
538                                          */
539                                         temp->ref_count++;
540                                         vm_object_lock_swap();
541
542                                         while (
543                                                 temp->paging_in_progress ||
544                                                 object->paging_in_progress
545                                         ) {
546                                                 vm_object_pip_wait(temp,
547                                                                    "objde1");
548                                                 vm_object_pip_wait(object,
549                                                                    "objde2");
550                                         }
551
552                                         if (temp->ref_count == 1) {
553                                                 temp->ref_count--;
554                                                 vm_object_unlock(object);
555                                                 object = temp;
556                                                 goto doterm;
557                                         }
558
559                                         lwkt_gettoken(&vm_token);
560                                         vm_object_collapse(temp);
561                                         lwkt_reltoken(&vm_token);
562                                         vm_object_unlock(object);
563                                         object = temp;
564                                         continue;
565                                 }
566                                 vm_object_unlock(temp);
567                         } else {
568                                 lwkt_reltoken(&vm_token);
569                         }
570                         vm_object_unlock(object);
571                         break;
572                 }
573
574                 /*
575                  * Normal dereferencing path
576                  */
577                 object->ref_count--;
578                 if (object->ref_count != 0) {
579                         lwkt_reltoken(&vm_token);
580                         vm_object_unlock(object);
581                         break;
582                 }
583
584                 /*
585                  * Termination path
586                  *
587                  * We may have to loop to resolve races if we block getting
588                  * temp's lock.  If temp is non NULL we have to swap the
589                  * lock order so the original object lock as at the top
590                  * of the lock heap.
591                  */
592                 lwkt_reltoken(&vm_token);
593 doterm:
594                 while ((temp = object->backing_object) != NULL) {
595                         vm_object_lock(temp);
596                         if (temp == object->backing_object)
597                                 break;
598                         vm_object_unlock(temp);
599                 }
600                 if (temp) {
601                         LIST_REMOVE(object, shadow_list);
602                         temp->shadow_count--;
603                         temp->generation++;
604                         object->backing_object = NULL;
605                         vm_object_lock_swap();
606                 }
607
608                 /*
609                  * Don't double-terminate, we could be in a termination
610                  * recursion due to the terminate having to sync data
611                  * to disk.
612                  */
613                 if ((object->flags & OBJ_DEAD) == 0) {
614                         vm_object_terminate(object);
615                         /* termination ate the object lock */
616                 } else {
617                         vm_object_unlock(object);
618                 }
619                 object = temp;
620         }
621 }
622
623 /*
624  * Destroy the specified object, freeing up related resources.
625  *
626  * The object must have zero references.
627  *
628  * The caller must be holding vmobj_token and properly interlock with
629  * OBJ_DEAD (at the moment).
630  *
631  * The caller must have locked the object only, and not be holding it.
632  * This function will eat the caller's lock on the object.
633  */
634 static int vm_object_terminate_callback(vm_page_t p, void *data);
635
636 void
637 vm_object_terminate(vm_object_t object)
638 {
639         /*
640          * Make sure no one uses us.  Once we set OBJ_DEAD we should be
641          * able to safely block.
642          */
643         KKASSERT((object->flags & OBJ_DEAD) == 0);
644         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
645         vm_object_set_flag(object, OBJ_DEAD);
646
647         /*
648          * Wait for the pageout daemon to be done with the object
649          */
650         vm_object_pip_wait(object, "objtrm1");
651
652         KASSERT(!object->paging_in_progress,
653                 ("vm_object_terminate: pageout in progress"));
654
655         /*
656          * Clean and free the pages, as appropriate. All references to the
657          * object are gone, so we don't need to lock it.
658          */
659         if (object->type == OBJT_VNODE) {
660                 struct vnode *vp;
661
662                 /*
663                  * Clean pages and flush buffers.
664                  */
665                 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
666
667                 vp = (struct vnode *) object->handle;
668                 vinvalbuf(vp, V_SAVE, 0, 0);
669         }
670
671         /*
672          * Wait for any I/O to complete, after which there had better not
673          * be any references left on the object.
674          */
675         vm_object_pip_wait(object, "objtrm2");
676
677         if (object->ref_count != 0) {
678                 panic("vm_object_terminate: object with references, "
679                       "ref_count=%d", object->ref_count);
680         }
681
682         /*
683          * Now free any remaining pages. For internal objects, this also
684          * removes them from paging queues. Don't free wired pages, just
685          * remove them from the object. 
686          */
687         lwkt_gettoken(&vm_token);
688         vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL,
689                                 vm_object_terminate_callback, NULL);
690         lwkt_reltoken(&vm_token);
691
692         /*
693          * Let the pager know object is dead.
694          */
695         vm_pager_deallocate(object);
696
697         /*
698          * Wait for the object hold count to hit zero, clean out pages as
699          * we go.
700          */
701         lwkt_gettoken(&vm_token);
702         for (;;) {
703                 vm_object_hold_wait(object);
704                 if (RB_ROOT(&object->rb_memq) == NULL)
705                         break;
706                 kprintf("vm_object_terminate: Warning, object %p "
707                         "still has %d pages\n",
708                         object, object->resident_page_count);
709                 vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL,
710                                         vm_object_terminate_callback, NULL);
711         }
712         lwkt_reltoken(&vm_token);
713
714         /*
715          * There had better not be any pages left
716          */
717         KKASSERT(object->resident_page_count == 0);
718
719         /*
720          * Remove the object from the global object list.
721          *
722          * (we are holding vmobj_token)
723          */
724         TAILQ_REMOVE(&vm_object_list, object, object_list);
725         vm_object_count--;
726         vm_object_dead_wakeup(object);
727         vm_object_unlock(object);
728
729         if (object->ref_count != 0) {
730                 panic("vm_object_terminate2: object with references, "
731                       "ref_count=%d", object->ref_count);
732         }
733
734         /*
735          * Free the space for the object.
736          */
737         zfree(obj_zone, object);
738 }
739
740 /*
741  * The caller must hold vm_token.
742  */
743 static int
744 vm_object_terminate_callback(vm_page_t p, void *data __unused)
745 {
746         if (p->busy || (p->flags & PG_BUSY))
747                 panic("vm_object_terminate: freeing busy page %p", p);
748         if (p->wire_count == 0) {
749                 vm_page_busy(p);
750                 vm_page_free(p);
751                 mycpu->gd_cnt.v_pfree++;
752         } else {
753                 if (p->queue != PQ_NONE)
754                         kprintf("vm_object_terminate: Warning: Encountered wired page %p on queue %d\n", p, p->queue);
755                 vm_page_busy(p);
756                 vm_page_remove(p);
757                 vm_page_wakeup(p);
758         }
759         return(0);
760 }
761
762 /*
763  * The object is dead but still has an object<->pager association.  Sleep
764  * and return.  The caller typically retests the association in a loop.
765  *
766  * Must be called with the vmobj_token held.
767  */
768 void
769 vm_object_dead_sleep(vm_object_t object, const char *wmesg)
770 {
771         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
772         if (object->handle) {
773                 vm_object_set_flag(object, OBJ_DEADWNT);
774                 tsleep(object, 0, wmesg, 0);
775                 /* object may be invalid after this point */
776         }
777 }
778
779 /*
780  * Wakeup anyone waiting for the object<->pager disassociation on
781  * a dead object.
782  *
783  * Must be called with the vmobj_token held.
784  */
785 void
786 vm_object_dead_wakeup(vm_object_t object)
787 {
788         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
789         if (object->flags & OBJ_DEADWNT) {
790                 vm_object_clear_flag(object, OBJ_DEADWNT);
791                 wakeup(object);
792         }
793 }
794
795 /*
796  * Clean all dirty pages in the specified range of object.  Leaves page
797  * on whatever queue it is currently on.   If NOSYNC is set then do not
798  * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
799  * leaving the object dirty.
800  *
801  * When stuffing pages asynchronously, allow clustering.  XXX we need a
802  * synchronous clustering mode implementation.
803  *
804  * Odd semantics: if start == end, we clean everything.
805  *
806  * The object must be locked? XXX
807  */
808 static int vm_object_page_clean_pass1(struct vm_page *p, void *data);
809 static int vm_object_page_clean_pass2(struct vm_page *p, void *data);
810
811 void
812 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
813                      int flags)
814 {
815         struct rb_vm_page_scan_info info;
816         struct vnode *vp;
817         int wholescan;
818         int pagerflags;
819         int curgeneration;
820
821         vm_object_hold(object);
822         if (object->type != OBJT_VNODE ||
823             (object->flags & OBJ_MIGHTBEDIRTY) == 0) {
824                 vm_object_drop(object);
825                 return;
826         }
827
828         pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? 
829                         VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
830         pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
831
832         vp = object->handle;
833
834         /*
835          * Interlock other major object operations.  This allows us to 
836          * temporarily clear OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY.
837          */
838         crit_enter();
839         vm_object_set_flag(object, OBJ_CLEANING);
840
841         /*
842          * Handle 'entire object' case
843          */
844         info.start_pindex = start;
845         if (end == 0) {
846                 info.end_pindex = object->size - 1;
847         } else {
848                 info.end_pindex = end - 1;
849         }
850         wholescan = (start == 0 && info.end_pindex == object->size - 1);
851         info.limit = flags;
852         info.pagerflags = pagerflags;
853         info.object = object;
854
855         /*
856          * If cleaning the entire object do a pass to mark the pages read-only.
857          * If everything worked out ok, clear OBJ_WRITEABLE and
858          * OBJ_MIGHTBEDIRTY.
859          */
860         if (wholescan) {
861                 info.error = 0;
862                 lwkt_gettoken(&vm_token);
863                 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
864                                         vm_object_page_clean_pass1, &info);
865                 lwkt_reltoken(&vm_token);
866                 if (info.error == 0) {
867                         vm_object_clear_flag(object,
868                                              OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
869                         if (object->type == OBJT_VNODE &&
870                             (vp = (struct vnode *)object->handle) != NULL) {
871                                 if (vp->v_flag & VOBJDIRTY) 
872                                         vclrflags(vp, VOBJDIRTY);
873                         }
874                 }
875         }
876
877         /*
878          * Do a pass to clean all the dirty pages we find.
879          */
880         do {
881                 info.error = 0;
882                 curgeneration = object->generation;
883                 lwkt_gettoken(&vm_token);
884                 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
885                                         vm_object_page_clean_pass2, &info);
886                 lwkt_reltoken(&vm_token);
887         } while (info.error || curgeneration != object->generation);
888
889         vm_object_clear_flag(object, OBJ_CLEANING);
890         crit_exit();
891         vm_object_drop(object);
892 }
893
894 /*
895  * The caller must hold vm_token.
896  */
897 static 
898 int
899 vm_object_page_clean_pass1(struct vm_page *p, void *data)
900 {
901         struct rb_vm_page_scan_info *info = data;
902
903         vm_page_flag_set(p, PG_CLEANCHK);
904         if ((info->limit & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
905                 info->error = 1;
906         else
907                 vm_page_protect(p, VM_PROT_READ);       /* must not block */
908         return(0);
909 }
910
911 /*
912  * The caller must hold vm_token.
913  */
914 static 
915 int
916 vm_object_page_clean_pass2(struct vm_page *p, void *data)
917 {
918         struct rb_vm_page_scan_info *info = data;
919         int n;
920
921         /*
922          * Do not mess with pages that were inserted after we started
923          * the cleaning pass.
924          */
925         if ((p->flags & PG_CLEANCHK) == 0)
926                 return(0);
927
928         /*
929          * Before wasting time traversing the pmaps, check for trivial
930          * cases where the page cannot be dirty.
931          */
932         if (p->valid == 0 || (p->queue - p->pc) == PQ_CACHE) {
933                 KKASSERT((p->dirty & p->valid) == 0);
934                 return(0);
935         }
936
937         /*
938          * Check whether the page is dirty or not.  The page has been set
939          * to be read-only so the check will not race a user dirtying the
940          * page.
941          */
942         vm_page_test_dirty(p);
943         if ((p->dirty & p->valid) == 0) {
944                 vm_page_flag_clear(p, PG_CLEANCHK);
945                 return(0);
946         }
947
948         /*
949          * If we have been asked to skip nosync pages and this is a
950          * nosync page, skip it.  Note that the object flags were
951          * not cleared in this case (because pass1 will have returned an
952          * error), so we do not have to set them.
953          */
954         if ((info->limit & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
955                 vm_page_flag_clear(p, PG_CLEANCHK);
956                 return(0);
957         }
958
959         /*
960          * Flush as many pages as we can.  PG_CLEANCHK will be cleared on
961          * the pages that get successfully flushed.  Set info->error if
962          * we raced an object modification.
963          */
964         n = vm_object_page_collect_flush(info->object, p, info->pagerflags);
965         if (n == 0)
966                 info->error = 1;
967         return(0);
968 }
969
970 /*
971  * Collect the specified page and nearby pages and flush them out.
972  * The number of pages flushed is returned.
973  *
974  * The caller must hold vm_token.
975  */
976 static int
977 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags)
978 {
979         int runlen;
980         int maxf;
981         int chkb;
982         int maxb;
983         int i;
984         int curgeneration;
985         vm_pindex_t pi;
986         vm_page_t maf[vm_pageout_page_count];
987         vm_page_t mab[vm_pageout_page_count];
988         vm_page_t ma[vm_pageout_page_count];
989
990         curgeneration = object->generation;
991
992         pi = p->pindex;
993         while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
994                 if (object->generation != curgeneration) {
995                         return(0);
996                 }
997         }
998         KKASSERT(p->object == object && p->pindex == pi);
999
1000         maxf = 0;
1001         for(i = 1; i < vm_pageout_page_count; i++) {
1002                 vm_page_t tp;
1003
1004                 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
1005                         if ((tp->flags & PG_BUSY) ||
1006                                 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 
1007                                  (tp->flags & PG_CLEANCHK) == 0) ||
1008                                 (tp->busy != 0))
1009                                 break;
1010                         if((tp->queue - tp->pc) == PQ_CACHE) {
1011                                 vm_page_flag_clear(tp, PG_CLEANCHK);
1012                                 break;
1013                         }
1014                         vm_page_test_dirty(tp);
1015                         if ((tp->dirty & tp->valid) == 0) {
1016                                 vm_page_flag_clear(tp, PG_CLEANCHK);
1017                                 break;
1018                         }
1019                         maf[ i - 1 ] = tp;
1020                         maxf++;
1021                         continue;
1022                 }
1023                 break;
1024         }
1025
1026         maxb = 0;
1027         chkb = vm_pageout_page_count -  maxf;
1028         if (chkb) {
1029                 for(i = 1; i < chkb;i++) {
1030                         vm_page_t tp;
1031
1032                         if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
1033                                 if ((tp->flags & PG_BUSY) ||
1034                                         ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 
1035                                          (tp->flags & PG_CLEANCHK) == 0) ||
1036                                         (tp->busy != 0))
1037                                         break;
1038                                 if((tp->queue - tp->pc) == PQ_CACHE) {
1039                                         vm_page_flag_clear(tp, PG_CLEANCHK);
1040                                         break;
1041                                 }
1042                                 vm_page_test_dirty(tp);
1043                                 if ((tp->dirty & tp->valid) == 0) {
1044                                         vm_page_flag_clear(tp, PG_CLEANCHK);
1045                                         break;
1046                                 }
1047                                 mab[ i - 1 ] = tp;
1048                                 maxb++;
1049                                 continue;
1050                         }
1051                         break;
1052                 }
1053         }
1054
1055         for(i = 0; i < maxb; i++) {
1056                 int index = (maxb - i) - 1;
1057                 ma[index] = mab[i];
1058                 vm_page_flag_clear(ma[index], PG_CLEANCHK);
1059         }
1060         vm_page_flag_clear(p, PG_CLEANCHK);
1061         ma[maxb] = p;
1062         for(i = 0; i < maxf; i++) {
1063                 int index = (maxb + i) + 1;
1064                 ma[index] = maf[i];
1065                 vm_page_flag_clear(ma[index], PG_CLEANCHK);
1066         }
1067         runlen = maxb + maxf + 1;
1068
1069         vm_pageout_flush(ma, runlen, pagerflags);
1070         for (i = 0; i < runlen; i++) {
1071                 if (ma[i]->valid & ma[i]->dirty) {
1072                         vm_page_protect(ma[i], VM_PROT_READ);
1073                         vm_page_flag_set(ma[i], PG_CLEANCHK);
1074
1075                         /*
1076                          * maxf will end up being the actual number of pages
1077                          * we wrote out contiguously, non-inclusive of the
1078                          * first page.  We do not count look-behind pages.
1079                          */
1080                         if (i >= maxb + 1 && (maxf > i - maxb - 1))
1081                                 maxf = i - maxb - 1;
1082                 }
1083         }
1084         return(maxf + 1);
1085 }
1086
1087 /*
1088  * Same as vm_object_pmap_copy, except range checking really
1089  * works, and is meant for small sections of an object.
1090  *
1091  * This code protects resident pages by making them read-only
1092  * and is typically called on a fork or split when a page
1093  * is converted to copy-on-write.  
1094  *
1095  * NOTE: If the page is already at VM_PROT_NONE, calling
1096  * vm_page_protect will have no effect.
1097  */
1098 void
1099 vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
1100 {
1101         vm_pindex_t idx;
1102         vm_page_t p;
1103
1104         if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
1105                 return;
1106
1107         /*
1108          * spl protection needed to prevent races between the lookup,
1109          * an interrupt unbusy/free, and our protect call.
1110          */
1111         crit_enter();
1112         lwkt_gettoken(&vm_token);
1113         for (idx = start; idx < end; idx++) {
1114                 p = vm_page_lookup(object, idx);
1115                 if (p == NULL)
1116                         continue;
1117                 vm_page_protect(p, VM_PROT_READ);
1118         }
1119         lwkt_reltoken(&vm_token);
1120         crit_exit();
1121 }
1122
1123 /*
1124  * Removes all physical pages in the specified object range from all
1125  * physical maps.
1126  *
1127  * The object must *not* be locked.
1128  */
1129
1130 static int vm_object_pmap_remove_callback(vm_page_t p, void *data);
1131
1132 void
1133 vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
1134 {
1135         struct rb_vm_page_scan_info info;
1136
1137         if (object == NULL)
1138                 return;
1139         info.start_pindex = start;
1140         info.end_pindex = end - 1;
1141
1142         crit_enter();
1143         lwkt_gettoken(&vm_token);
1144         vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
1145                                 vm_object_pmap_remove_callback, &info);
1146         if (start == 0 && end == object->size)
1147                 vm_object_clear_flag(object, OBJ_WRITEABLE);
1148         lwkt_reltoken(&vm_token);
1149         crit_exit();
1150 }
1151
1152 /*
1153  * The caller must hold vm_token.
1154  */
1155 static int
1156 vm_object_pmap_remove_callback(vm_page_t p, void *data __unused)
1157 {
1158         vm_page_protect(p, VM_PROT_NONE);
1159         return(0);
1160 }
1161
1162 /*
1163  * Implements the madvise function at the object/page level.
1164  *
1165  * MADV_WILLNEED        (any object)
1166  *
1167  *      Activate the specified pages if they are resident.
1168  *
1169  * MADV_DONTNEED        (any object)
1170  *
1171  *      Deactivate the specified pages if they are resident.
1172  *
1173  * MADV_FREE    (OBJT_DEFAULT/OBJT_SWAP objects, OBJ_ONEMAPPING only)
1174  *
1175  *      Deactivate and clean the specified pages if they are
1176  *      resident.  This permits the process to reuse the pages
1177  *      without faulting or the kernel to reclaim the pages
1178  *      without I/O.
1179  *
1180  * No requirements.
1181  */
1182 void
1183 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
1184 {
1185         vm_pindex_t end, tpindex;
1186         vm_object_t tobject;
1187         vm_page_t m;
1188
1189         if (object == NULL)
1190                 return;
1191
1192         end = pindex + count;
1193
1194         lwkt_gettoken(&vm_token);
1195
1196         /*
1197          * Locate and adjust resident pages
1198          */
1199         for (; pindex < end; pindex += 1) {
1200 relookup:
1201                 tobject = object;
1202                 tpindex = pindex;
1203 shadowlookup:
1204                 /*
1205                  * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1206                  * and those pages must be OBJ_ONEMAPPING.
1207                  */
1208                 if (advise == MADV_FREE) {
1209                         if ((tobject->type != OBJT_DEFAULT &&
1210                              tobject->type != OBJT_SWAP) ||
1211                             (tobject->flags & OBJ_ONEMAPPING) == 0) {
1212                                 continue;
1213                         }
1214                 }
1215
1216                 /*
1217                  * spl protection is required to avoid a race between the
1218                  * lookup, an interrupt unbusy/free, and our busy check.
1219                  */
1220
1221                 crit_enter();
1222                 m = vm_page_lookup(tobject, tpindex);
1223
1224                 if (m == NULL) {
1225                         /*
1226                          * There may be swap even if there is no backing page
1227                          */
1228                         if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1229                                 swap_pager_freespace(tobject, tpindex, 1);
1230
1231                         /*
1232                          * next object
1233                          */
1234                         crit_exit();
1235                         if (tobject->backing_object == NULL)
1236                                 continue;
1237                         tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1238                         tobject = tobject->backing_object;
1239                         goto shadowlookup;
1240                 }
1241
1242                 /*
1243                  * If the page is busy or not in a normal active state,
1244                  * we skip it.  If the page is not managed there are no
1245                  * page queues to mess with.  Things can break if we mess
1246                  * with pages in any of the below states.
1247                  */
1248                 if (
1249                     m->hold_count ||
1250                     m->wire_count ||
1251                     (m->flags & PG_UNMANAGED) ||
1252                     m->valid != VM_PAGE_BITS_ALL
1253                 ) {
1254                         crit_exit();
1255                         continue;
1256                 }
1257
1258                 if (vm_page_sleep_busy(m, TRUE, "madvpo")) {
1259                         crit_exit();
1260                         goto relookup;
1261                 }
1262                 vm_page_busy(m);
1263                 crit_exit();
1264
1265                 /*
1266                  * Theoretically once a page is known not to be busy, an
1267                  * interrupt cannot come along and rip it out from under us.
1268                  */
1269
1270                 if (advise == MADV_WILLNEED) {
1271                         vm_page_activate(m);
1272                 } else if (advise == MADV_DONTNEED) {
1273                         vm_page_dontneed(m);
1274                 } else if (advise == MADV_FREE) {
1275                         /*
1276                          * Mark the page clean.  This will allow the page
1277                          * to be freed up by the system.  However, such pages
1278                          * are often reused quickly by malloc()/free()
1279                          * so we do not do anything that would cause
1280                          * a page fault if we can help it.
1281                          *
1282                          * Specifically, we do not try to actually free
1283                          * the page now nor do we try to put it in the
1284                          * cache (which would cause a page fault on reuse).
1285                          *
1286                          * But we do make the page is freeable as we
1287                          * can without actually taking the step of unmapping
1288                          * it.
1289                          */
1290                         pmap_clear_modify(m);
1291                         m->dirty = 0;
1292                         m->act_count = 0;
1293                         vm_page_dontneed(m);
1294                         if (tobject->type == OBJT_SWAP)
1295                                 swap_pager_freespace(tobject, tpindex, 1);
1296                 }
1297                 vm_page_wakeup(m);
1298         }       
1299         lwkt_reltoken(&vm_token);
1300 }
1301
1302 /*
1303  * Create a new object which is backed by the specified existing object
1304  * range.  The source object reference is deallocated.
1305  *
1306  * The new object and offset into that object are returned in the source
1307  * parameters.
1308  *
1309  * No other requirements.
1310  */
1311 void
1312 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length)
1313 {
1314         vm_object_t source;
1315         vm_object_t result;
1316
1317         source = *object;
1318
1319         /*
1320          * Don't create the new object if the old object isn't shared.
1321          */
1322         lwkt_gettoken(&vm_token);
1323
1324         if (source != NULL &&
1325             source->ref_count == 1 &&
1326             source->handle == NULL &&
1327             (source->type == OBJT_DEFAULT ||
1328              source->type == OBJT_SWAP)) {
1329                 lwkt_reltoken(&vm_token);
1330                 return;
1331         }
1332
1333         /*
1334          * Allocate a new object with the given length
1335          */
1336
1337         if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL)
1338                 panic("vm_object_shadow: no object for shadowing");
1339
1340         /*
1341          * The new object shadows the source object, adding a reference to it.
1342          * Our caller changes his reference to point to the new object,
1343          * removing a reference to the source object.  Net result: no change
1344          * of reference count.
1345          *
1346          * Try to optimize the result object's page color when shadowing
1347          * in order to maintain page coloring consistency in the combined 
1348          * shadowed object.
1349          */
1350         result->backing_object = source;
1351         if (source) {
1352                 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
1353                 source->shadow_count++;
1354                 source->generation++;
1355                 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1356         }
1357
1358         /*
1359          * Store the offset into the source object, and fix up the offset into
1360          * the new object.
1361          */
1362         result->backing_object_offset = *offset;
1363         lwkt_reltoken(&vm_token);
1364
1365         /*
1366          * Return the new things
1367          */
1368         *offset = 0;
1369         *object = result;
1370 }
1371
1372 #define OBSC_TEST_ALL_SHADOWED  0x0001
1373 #define OBSC_COLLAPSE_NOWAIT    0x0002
1374 #define OBSC_COLLAPSE_WAIT      0x0004
1375
1376 static int vm_object_backing_scan_callback(vm_page_t p, void *data);
1377
1378 /*
1379  * The caller must hold vm_token.
1380  */
1381 static __inline int
1382 vm_object_backing_scan(vm_object_t object, int op)
1383 {
1384         struct rb_vm_page_scan_info info;
1385         vm_object_t backing_object;
1386
1387         crit_enter();
1388
1389         backing_object = object->backing_object;
1390         info.backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1391
1392         /*
1393          * Initial conditions
1394          */
1395
1396         if (op & OBSC_TEST_ALL_SHADOWED) {
1397                 /*
1398                  * We do not want to have to test for the existence of
1399                  * swap pages in the backing object.  XXX but with the
1400                  * new swapper this would be pretty easy to do.
1401                  *
1402                  * XXX what about anonymous MAP_SHARED memory that hasn't
1403                  * been ZFOD faulted yet?  If we do not test for this, the
1404                  * shadow test may succeed! XXX
1405                  */
1406                 if (backing_object->type != OBJT_DEFAULT) {
1407                         crit_exit();
1408                         return(0);
1409                 }
1410         }
1411         if (op & OBSC_COLLAPSE_WAIT) {
1412                 KKASSERT((backing_object->flags & OBJ_DEAD) == 0);
1413                 vm_object_set_flag(backing_object, OBJ_DEAD);
1414         }
1415
1416         /*
1417          * Our scan.   We have to retry if a negative error code is returned,
1418          * otherwise 0 or 1 will be returned in info.error.  0 Indicates that
1419          * the scan had to be stopped because the parent does not completely
1420          * shadow the child.
1421          */
1422         info.object = object;
1423         info.backing_object = backing_object;
1424         info.limit = op;
1425         do {
1426                 info.error = 1;
1427                 vm_page_rb_tree_RB_SCAN(&backing_object->rb_memq, NULL,
1428                                         vm_object_backing_scan_callback,
1429                                         &info);
1430         } while (info.error < 0);
1431         crit_exit();
1432         return(info.error);
1433 }
1434
1435 /*
1436  * The caller must hold vm_token.
1437  */
1438 static int
1439 vm_object_backing_scan_callback(vm_page_t p, void *data)
1440 {
1441         struct rb_vm_page_scan_info *info = data;
1442         vm_object_t backing_object;
1443         vm_object_t object;
1444         vm_pindex_t new_pindex;
1445         vm_pindex_t backing_offset_index;
1446         int op;
1447
1448         new_pindex = p->pindex - info->backing_offset_index;
1449         op = info->limit;
1450         object = info->object;
1451         backing_object = info->backing_object;
1452         backing_offset_index = info->backing_offset_index;
1453
1454         if (op & OBSC_TEST_ALL_SHADOWED) {
1455                 vm_page_t pp;
1456
1457                 /*
1458                  * Ignore pages outside the parent object's range
1459                  * and outside the parent object's mapping of the 
1460                  * backing object.
1461                  *
1462                  * note that we do not busy the backing object's
1463                  * page.
1464                  */
1465                 if (
1466                     p->pindex < backing_offset_index ||
1467                     new_pindex >= object->size
1468                 ) {
1469                         return(0);
1470                 }
1471
1472                 /*
1473                  * See if the parent has the page or if the parent's
1474                  * object pager has the page.  If the parent has the
1475                  * page but the page is not valid, the parent's
1476                  * object pager must have the page.
1477                  *
1478                  * If this fails, the parent does not completely shadow
1479                  * the object and we might as well give up now.
1480                  */
1481
1482                 pp = vm_page_lookup(object, new_pindex);
1483                 if ((pp == NULL || pp->valid == 0) &&
1484                     !vm_pager_has_page(object, new_pindex)
1485                 ) {
1486                         info->error = 0;        /* problemo */
1487                         return(-1);             /* stop the scan */
1488                 }
1489         }
1490
1491         /*
1492          * Check for busy page
1493          */
1494
1495         if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1496                 vm_page_t pp;
1497
1498                 if (op & OBSC_COLLAPSE_NOWAIT) {
1499                         if (
1500                             (p->flags & PG_BUSY) ||
1501                             !p->valid || 
1502                             p->hold_count || 
1503                             p->wire_count ||
1504                             p->busy
1505                         ) {
1506                                 return(0);
1507                         }
1508                 } else if (op & OBSC_COLLAPSE_WAIT) {
1509                         if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1510                                 /*
1511                                  * If we slept, anything could have
1512                                  * happened.   Ask that the scan be restarted.
1513                                  *
1514                                  * Since the object is marked dead, the
1515                                  * backing offset should not have changed.  
1516                                  */
1517                                 info->error = -1;
1518                                 return(-1);
1519                         }
1520                 }
1521
1522                 /* 
1523                  * Busy the page
1524                  */
1525                 vm_page_busy(p);
1526
1527                 KASSERT(
1528                     p->object == backing_object,
1529                     ("vm_object_qcollapse(): object mismatch")
1530                 );
1531
1532                 /*
1533                  * Destroy any associated swap
1534                  */
1535                 if (backing_object->type == OBJT_SWAP)
1536                         swap_pager_freespace(backing_object, p->pindex, 1);
1537
1538                 if (
1539                     p->pindex < backing_offset_index ||
1540                     new_pindex >= object->size
1541                 ) {
1542                         /*
1543                          * Page is out of the parent object's range, we 
1544                          * can simply destroy it. 
1545                          */
1546                         vm_page_protect(p, VM_PROT_NONE);
1547                         vm_page_free(p);
1548                         return(0);
1549                 }
1550
1551                 pp = vm_page_lookup(object, new_pindex);
1552                 if (pp != NULL || vm_pager_has_page(object, new_pindex)) {
1553                         /*
1554                          * page already exists in parent OR swap exists
1555                          * for this location in the parent.  Destroy 
1556                          * the original page from the backing object.
1557                          *
1558                          * Leave the parent's page alone
1559                          */
1560                         vm_page_protect(p, VM_PROT_NONE);
1561                         vm_page_free(p);
1562                         return(0);
1563                 }
1564
1565                 /*
1566                  * Page does not exist in parent, rename the
1567                  * page from the backing object to the main object. 
1568                  *
1569                  * If the page was mapped to a process, it can remain 
1570                  * mapped through the rename.
1571                  */
1572                 if ((p->queue - p->pc) == PQ_CACHE)
1573                         vm_page_deactivate(p);
1574
1575                 vm_page_rename(p, object, new_pindex);
1576                 /* page automatically made dirty by rename */
1577         }
1578         return(0);
1579 }
1580
1581 /*
1582  * This version of collapse allows the operation to occur earlier and
1583  * when paging_in_progress is true for an object...  This is not a complete
1584  * operation, but should plug 99.9% of the rest of the leaks.
1585  *
1586  * The caller must hold vm_token and vmobj_token.
1587  * (only called from vm_object_collapse)
1588  */
1589 static void
1590 vm_object_qcollapse(vm_object_t object)
1591 {
1592         vm_object_t backing_object = object->backing_object;
1593
1594         if (backing_object->ref_count != 1)
1595                 return;
1596
1597         backing_object->ref_count += 2;
1598
1599         vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1600
1601         backing_object->ref_count -= 2;
1602 }
1603
1604 /*
1605  * Collapse an object with the object backing it.  Pages in the backing
1606  * object are moved into the parent, and the backing object is deallocated.
1607  *
1608  * The caller must hold (object).
1609  */
1610 void
1611 vm_object_collapse(vm_object_t object)
1612 {
1613         ASSERT_LWKT_TOKEN_HELD(&vm_token);
1614         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
1615         vm_object_assert_held(object);
1616
1617         while (TRUE) {
1618                 vm_object_t backing_object;
1619
1620                 /*
1621                  * Verify that the conditions are right for collapse:
1622                  *
1623                  * The object exists and the backing object exists.
1624                  */
1625                 if (object == NULL)
1626                         break;
1627
1628                 if ((backing_object = object->backing_object) == NULL)
1629                         break;
1630
1631                 vm_object_hold(backing_object);
1632                 if (backing_object != object->backing_object) {
1633                         vm_object_drop(backing_object);
1634                         continue;
1635                 }
1636
1637                 /*
1638                  * we check the backing object first, because it is most likely
1639                  * not collapsable.
1640                  */
1641                 if (backing_object->handle != NULL ||
1642                     (backing_object->type != OBJT_DEFAULT &&
1643                      backing_object->type != OBJT_SWAP) ||
1644                     (backing_object->flags & OBJ_DEAD) ||
1645                     object->handle != NULL ||
1646                     (object->type != OBJT_DEFAULT &&
1647                      object->type != OBJT_SWAP) ||
1648                     (object->flags & OBJ_DEAD)) {
1649                         vm_object_drop(backing_object);
1650                         break;
1651                 }
1652
1653                 if (
1654                     object->paging_in_progress != 0 ||
1655                     backing_object->paging_in_progress != 0
1656                 ) {
1657                         vm_object_drop(backing_object);
1658                         vm_object_qcollapse(object);
1659                         break;
1660                 }
1661
1662                 /*
1663                  * We know that we can either collapse the backing object (if
1664                  * the parent is the only reference to it) or (perhaps) have
1665                  * the parent bypass the object if the parent happens to shadow
1666                  * all the resident pages in the entire backing object.
1667                  *
1668                  * This is ignoring pager-backed pages such as swap pages.
1669                  * vm_object_backing_scan fails the shadowing test in this
1670                  * case.
1671                  */
1672
1673                 if (backing_object->ref_count == 1) {
1674                         /*
1675                          * If there is exactly one reference to the backing
1676                          * object, we can collapse it into the parent.  
1677                          */
1678                         vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1679
1680                         /*
1681                          * Move the pager from backing_object to object.
1682                          */
1683
1684                         if (backing_object->type == OBJT_SWAP) {
1685                                 vm_object_pip_add(backing_object, 1);
1686
1687                                 /*
1688                                  * scrap the paging_offset junk and do a 
1689                                  * discrete copy.  This also removes major 
1690                                  * assumptions about how the swap-pager 
1691                                  * works from where it doesn't belong.  The
1692                                  * new swapper is able to optimize the
1693                                  * destroy-source case.
1694                                  */
1695
1696                                 vm_object_pip_add(object, 1);
1697                                 swap_pager_copy(
1698                                     backing_object,
1699                                     object,
1700                                     OFF_TO_IDX(object->backing_object_offset), TRUE);
1701                                 vm_object_pip_wakeup(object);
1702
1703                                 vm_object_pip_wakeup(backing_object);
1704                         }
1705                         /*
1706                          * Object now shadows whatever backing_object did.
1707                          * Note that the reference to 
1708                          * backing_object->backing_object moves from within 
1709                          * backing_object to within object.
1710                          */
1711
1712                         LIST_REMOVE(object, shadow_list);
1713                         object->backing_object->shadow_count--;
1714                         object->backing_object->generation++;
1715                         if (backing_object->backing_object) {
1716                                 LIST_REMOVE(backing_object, shadow_list);
1717                                 backing_object->backing_object->shadow_count--;
1718                                 backing_object->backing_object->generation++;
1719                         }
1720                         object->backing_object = backing_object->backing_object;
1721                         if (object->backing_object) {
1722                                 LIST_INSERT_HEAD(
1723                                     &object->backing_object->shadow_head,
1724                                     object, 
1725                                     shadow_list
1726                                 );
1727                                 object->backing_object->shadow_count++;
1728                                 object->backing_object->generation++;
1729                         }
1730
1731                         object->backing_object_offset +=
1732                             backing_object->backing_object_offset;
1733
1734                         /*
1735                          * Discard backing_object.
1736                          *
1737                          * Since the backing object has no pages, no pager left,
1738                          * and no object references within it, all that is
1739                          * necessary is to dispose of it.
1740                          */
1741
1742                         KASSERT(backing_object->ref_count == 1,
1743                                 ("backing_object %p was somehow "
1744                                  "re-referenced during collapse!",
1745                                  backing_object));
1746                         KASSERT(RB_EMPTY(&backing_object->rb_memq),
1747                                 ("backing_object %p somehow has left "
1748                                  "over pages during collapse!",
1749                                  backing_object));
1750
1751                         /*
1752                          * Wait for hold count to hit zero
1753                          */
1754                         vm_object_drop(backing_object);
1755                         vm_object_hold_wait(backing_object);
1756
1757                         /* (we are holding vmobj_token) */
1758                         TAILQ_REMOVE(&vm_object_list, backing_object,
1759                                      object_list);
1760                         --backing_object->ref_count;    /* safety/debug */
1761                         vm_object_count--;
1762
1763                         zfree(obj_zone, backing_object);
1764
1765                         object_collapses++;
1766                 } else {
1767                         vm_object_t new_backing_object;
1768
1769                         /*
1770                          * If we do not entirely shadow the backing object,
1771                          * there is nothing we can do so we give up.
1772                          */
1773
1774                         if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1775                                 vm_object_drop(backing_object);
1776                                 break;
1777                         }
1778
1779                         /*
1780                          * Make the parent shadow the next object in the
1781                          * chain.  Deallocating backing_object will not remove
1782                          * it, since its reference count is at least 2.
1783                          */
1784
1785                         LIST_REMOVE(object, shadow_list);
1786                         backing_object->shadow_count--;
1787                         backing_object->generation++;
1788
1789                         new_backing_object = backing_object->backing_object;
1790                         if ((object->backing_object = new_backing_object) != NULL) {
1791                                 vm_object_reference(new_backing_object);
1792                                 LIST_INSERT_HEAD(
1793                                     &new_backing_object->shadow_head,
1794                                     object,
1795                                     shadow_list
1796                                 );
1797                                 new_backing_object->shadow_count++;
1798                                 new_backing_object->generation++;
1799                                 object->backing_object_offset +=
1800                                         backing_object->backing_object_offset;
1801                         }
1802
1803                         /*
1804                          * Drop the reference count on backing_object. Since
1805                          * its ref_count was at least 2, it will not vanish;
1806                          * so we don't need to call vm_object_deallocate, but
1807                          * we do anyway.
1808                          */
1809                         vm_object_drop(backing_object);
1810                         vm_object_deallocate_locked(backing_object);
1811                         object_bypasses++;
1812                 }
1813
1814                 /*
1815                  * Try again with this object's new backing object.
1816                  */
1817         }
1818 }
1819
1820 /*
1821  * Removes all physical pages in the specified object range from the
1822  * object's list of pages.
1823  *
1824  * No requirements.
1825  */
1826 static int vm_object_page_remove_callback(vm_page_t p, void *data);
1827
1828 void
1829 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
1830                       boolean_t clean_only)
1831 {
1832         struct rb_vm_page_scan_info info;
1833         int all;
1834
1835         /*
1836          * Degenerate cases and assertions
1837          */
1838         lwkt_gettoken(&vm_token);
1839         if (object == NULL ||
1840             (object->resident_page_count == 0 && object->swblock_count == 0)) {
1841                 lwkt_reltoken(&vm_token);
1842                 return;
1843         }
1844         KASSERT(object->type != OBJT_PHYS, 
1845                 ("attempt to remove pages from a physical object"));
1846
1847         /*
1848          * Indicate that paging is occuring on the object
1849          */
1850         crit_enter();
1851         vm_object_pip_add(object, 1);
1852
1853         /*
1854          * Figure out the actual removal range and whether we are removing
1855          * the entire contents of the object or not.  If removing the entire
1856          * contents, be sure to get all pages, even those that might be 
1857          * beyond the end of the object.
1858          */
1859         info.start_pindex = start;
1860         if (end == 0)
1861                 info.end_pindex = (vm_pindex_t)-1;
1862         else
1863                 info.end_pindex = end - 1;
1864         info.limit = clean_only;
1865         all = (start == 0 && info.end_pindex >= object->size - 1);
1866
1867         /*
1868          * Loop until we are sure we have gotten them all.
1869          */
1870         do {
1871                 info.error = 0;
1872                 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
1873                                         vm_object_page_remove_callback, &info);
1874         } while (info.error);
1875
1876         /*
1877          * Remove any related swap if throwing away pages, or for
1878          * non-swap objects (the swap is a clean copy in that case).
1879          */
1880         if (object->type != OBJT_SWAP || clean_only == FALSE) {
1881                 if (all)
1882                         swap_pager_freespace_all(object);
1883                 else
1884                         swap_pager_freespace(object, info.start_pindex,
1885                              info.end_pindex - info.start_pindex + 1);
1886         }
1887
1888         /*
1889          * Cleanup
1890          */
1891         vm_object_pip_wakeup(object);
1892         crit_exit();
1893         lwkt_reltoken(&vm_token);
1894 }
1895
1896 /*
1897  * The caller must hold vm_token.
1898  */
1899 static int
1900 vm_object_page_remove_callback(vm_page_t p, void *data)
1901 {
1902         struct rb_vm_page_scan_info *info = data;
1903
1904         /*
1905          * Wired pages cannot be destroyed, but they can be invalidated
1906          * and we do so if clean_only (limit) is not set.
1907          *
1908          * WARNING!  The page may be wired due to being part of a buffer
1909          *           cache buffer, and the buffer might be marked B_CACHE.
1910          *           This is fine as part of a truncation but VFSs must be
1911          *           sure to fix the buffer up when re-extending the file.
1912          */
1913         if (p->wire_count != 0) {
1914                 vm_page_protect(p, VM_PROT_NONE);
1915                 if (info->limit == 0)
1916                         p->valid = 0;
1917                 return(0);
1918         }
1919
1920         /*
1921          * The busy flags are only cleared at
1922          * interrupt -- minimize the spl transitions
1923          */
1924
1925         if (vm_page_sleep_busy(p, TRUE, "vmopar")) {
1926                 info->error = 1;
1927                 return(0);
1928         }
1929
1930         /*
1931          * limit is our clean_only flag.  If set and the page is dirty, do
1932          * not free it.  If set and the page is being held by someone, do
1933          * not free it.
1934          */
1935         if (info->limit && p->valid) {
1936                 vm_page_test_dirty(p);
1937                 if (p->valid & p->dirty)
1938                         return(0);
1939                 if (p->hold_count)
1940                         return(0);
1941         }
1942
1943         /*
1944          * Destroy the page
1945          */
1946         vm_page_busy(p);
1947         vm_page_protect(p, VM_PROT_NONE);
1948         vm_page_free(p);
1949         return(0);
1950 }
1951
1952 /*
1953  * Coalesces two objects backing up adjoining regions of memory into a
1954  * single object.
1955  *
1956  * returns TRUE if objects were combined.
1957  *
1958  * NOTE: Only works at the moment if the second object is NULL -
1959  *       if it's not, which object do we lock first?
1960  *
1961  * Parameters:
1962  *      prev_object     First object to coalesce
1963  *      prev_offset     Offset into prev_object
1964  *      next_object     Second object into coalesce
1965  *      next_offset     Offset into next_object
1966  *
1967  *      prev_size       Size of reference to prev_object
1968  *      next_size       Size of reference to next_object
1969  *
1970  * The caller must hold vm_token and vmobj_token.
1971  *
1972  * The caller does not need to hold (prev_object) but must have a stable
1973  * pointer to it (typically by holding the vm_map locked).
1974  */
1975 boolean_t
1976 vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
1977                    vm_size_t prev_size, vm_size_t next_size)
1978 {
1979         vm_pindex_t next_pindex;
1980
1981         ASSERT_LWKT_TOKEN_HELD(&vm_token);
1982         ASSERT_LWKT_TOKEN_HELD(&vmobj_token);
1983
1984         if (prev_object == NULL) {
1985                 return (TRUE);
1986         }
1987
1988         vm_object_hold(prev_object);
1989
1990         if (prev_object->type != OBJT_DEFAULT &&
1991             prev_object->type != OBJT_SWAP) {
1992                 vm_object_drop(prev_object);
1993                 return (FALSE);
1994         }
1995
1996         /*
1997          * Try to collapse the object first
1998          */
1999         vm_object_collapse(prev_object);
2000
2001         /*
2002          * Can't coalesce if: . more than one reference . paged out . shadows
2003          * another object . has a copy elsewhere (any of which mean that the
2004          * pages not mapped to prev_entry may be in use anyway)
2005          */
2006
2007         if (prev_object->backing_object != NULL) {
2008                 vm_object_drop(prev_object);
2009                 return (FALSE);
2010         }
2011
2012         prev_size >>= PAGE_SHIFT;
2013         next_size >>= PAGE_SHIFT;
2014         next_pindex = prev_pindex + prev_size;
2015
2016         if ((prev_object->ref_count > 1) &&
2017             (prev_object->size != next_pindex)) {
2018                 vm_object_drop(prev_object);
2019                 return (FALSE);
2020         }
2021
2022         /*
2023          * Remove any pages that may still be in the object from a previous
2024          * deallocation.
2025          */
2026         if (next_pindex < prev_object->size) {
2027                 vm_object_page_remove(prev_object,
2028                                       next_pindex,
2029                                       next_pindex + next_size, FALSE);
2030                 if (prev_object->type == OBJT_SWAP)
2031                         swap_pager_freespace(prev_object,
2032                                              next_pindex, next_size);
2033         }
2034
2035         /*
2036          * Extend the object if necessary.
2037          */
2038         if (next_pindex + next_size > prev_object->size)
2039                 prev_object->size = next_pindex + next_size;
2040
2041         vm_object_drop(prev_object);
2042         return (TRUE);
2043 }
2044
2045 /*
2046  * Make the object writable and flag is being possibly dirty.
2047  *
2048  * No requirements.
2049  */
2050 void
2051 vm_object_set_writeable_dirty(vm_object_t object)
2052 {
2053         struct vnode *vp;
2054
2055         lwkt_gettoken(&vm_token);
2056         vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
2057         if (object->type == OBJT_VNODE &&
2058             (vp = (struct vnode *)object->handle) != NULL) {
2059                 if ((vp->v_flag & VOBJDIRTY) == 0) {
2060                         vsetflags(vp, VOBJDIRTY);
2061                 }
2062         }
2063         lwkt_reltoken(&vm_token);
2064 }
2065
2066 #include "opt_ddb.h"
2067 #ifdef DDB
2068 #include <sys/kernel.h>
2069
2070 #include <sys/cons.h>
2071
2072 #include <ddb/ddb.h>
2073
2074 static int      _vm_object_in_map (vm_map_t map, vm_object_t object,
2075                                        vm_map_entry_t entry);
2076 static int      vm_object_in_map (vm_object_t object);
2077
2078 /*
2079  * The caller must hold vm_token.
2080  */
2081 static int
2082 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
2083 {
2084         vm_map_t tmpm;
2085         vm_map_entry_t tmpe;
2086         vm_object_t obj;
2087         int entcount;
2088
2089         if (map == 0)
2090                 return 0;
2091         if (entry == 0) {
2092                 tmpe = map->header.next;
2093                 entcount = map->nentries;
2094                 while (entcount-- && (tmpe != &map->header)) {
2095                         if( _vm_object_in_map(map, object, tmpe)) {
2096                                 return 1;
2097                         }
2098                         tmpe = tmpe->next;
2099                 }
2100                 return (0);
2101         }
2102         switch(entry->maptype) {
2103         case VM_MAPTYPE_SUBMAP:
2104                 tmpm = entry->object.sub_map;
2105                 tmpe = tmpm->header.next;
2106                 entcount = tmpm->nentries;
2107                 while (entcount-- && tmpe != &tmpm->header) {
2108                         if( _vm_object_in_map(tmpm, object, tmpe)) {
2109                                 return 1;
2110                         }
2111                         tmpe = tmpe->next;
2112                 }
2113                 break;
2114         case VM_MAPTYPE_NORMAL:
2115         case VM_MAPTYPE_VPAGETABLE:
2116                 obj = entry->object.vm_object;
2117                 while (obj) {
2118                         if (obj == object)
2119                                 return 1;
2120                         obj = obj->backing_object;
2121                 }
2122                 break;
2123         default:
2124                 break;
2125         }
2126         return 0;
2127 }
2128
2129 static int vm_object_in_map_callback(struct proc *p, void *data);
2130
2131 struct vm_object_in_map_info {
2132         vm_object_t object;
2133         int rv;
2134 };
2135
2136 /*
2137  * Debugging only
2138  */
2139 static int
2140 vm_object_in_map(vm_object_t object)
2141 {
2142         struct vm_object_in_map_info info;
2143
2144         info.rv = 0;
2145         info.object = object;
2146
2147         allproc_scan(vm_object_in_map_callback, &info);
2148         if (info.rv)
2149                 return 1;
2150         if( _vm_object_in_map(&kernel_map, object, 0))
2151                 return 1;
2152         if( _vm_object_in_map(&pager_map, object, 0))
2153                 return 1;
2154         if( _vm_object_in_map(&buffer_map, object, 0))
2155                 return 1;
2156         return 0;
2157 }
2158
2159 /*
2160  * Debugging only
2161  */
2162 static int
2163 vm_object_in_map_callback(struct proc *p, void *data)
2164 {
2165         struct vm_object_in_map_info *info = data;
2166
2167         if (p->p_vmspace) {
2168                 if (_vm_object_in_map(&p->p_vmspace->vm_map, info->object, 0)) {
2169                         info->rv = 1;
2170                         return -1;
2171                 }
2172         }
2173         return (0);
2174 }
2175
2176 DB_SHOW_COMMAND(vmochk, vm_object_check)
2177 {
2178         vm_object_t object;
2179
2180         /*
2181          * make sure that internal objs are in a map somewhere
2182          * and none have zero ref counts.
2183          */
2184         for (object = TAILQ_FIRST(&vm_object_list);
2185                         object != NULL;
2186                         object = TAILQ_NEXT(object, object_list)) {
2187                 if (object->type == OBJT_MARKER)
2188                         continue;
2189                 if (object->handle == NULL &&
2190                     (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
2191                         if (object->ref_count == 0) {
2192                                 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2193                                         (long)object->size);
2194                         }
2195                         if (!vm_object_in_map(object)) {
2196                                 db_printf(
2197                         "vmochk: internal obj is not in a map: "
2198                         "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2199                                     object->ref_count, (u_long)object->size, 
2200                                     (u_long)object->size,
2201                                     (void *)object->backing_object);
2202                         }
2203                 }
2204         }
2205 }
2206
2207 /*
2208  * Debugging only
2209  */
2210 DB_SHOW_COMMAND(object, vm_object_print_static)
2211 {
2212         /* XXX convert args. */
2213         vm_object_t object = (vm_object_t)addr;
2214         boolean_t full = have_addr;
2215
2216         vm_page_t p;
2217
2218         /* XXX count is an (unused) arg.  Avoid shadowing it. */
2219 #define count   was_count
2220
2221         int count;
2222
2223         if (object == NULL)
2224                 return;
2225
2226         db_iprintf(
2227             "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
2228             object, (int)object->type, (u_long)object->size,
2229             object->resident_page_count, object->ref_count, object->flags);
2230         /*
2231          * XXX no %qd in kernel.  Truncate object->backing_object_offset.
2232          */
2233         db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
2234             object->shadow_count, 
2235             object->backing_object ? object->backing_object->ref_count : 0,
2236             object->backing_object, (long)object->backing_object_offset);
2237
2238         if (!full)
2239                 return;
2240
2241         db_indent += 2;
2242         count = 0;
2243         RB_FOREACH(p, vm_page_rb_tree, &object->rb_memq) {
2244                 if (count == 0)
2245                         db_iprintf("memory:=");
2246                 else if (count == 6) {
2247                         db_printf("\n");
2248                         db_iprintf(" ...");
2249                         count = 0;
2250                 } else
2251                         db_printf(",");
2252                 count++;
2253
2254                 db_printf("(off=0x%lx,page=0x%lx)",
2255                     (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
2256         }
2257         if (count != 0)
2258                 db_printf("\n");
2259         db_indent -= 2;
2260 }
2261
2262 /* XXX. */
2263 #undef count
2264
2265 /*
2266  * XXX need this non-static entry for calling from vm_map_print.
2267  *
2268  * Debugging only
2269  */
2270 void
2271 vm_object_print(/* db_expr_t */ long addr,
2272                 boolean_t have_addr,
2273                 /* db_expr_t */ long count,
2274                 char *modif)
2275 {
2276         vm_object_print_static(addr, have_addr, count, modif);
2277 }
2278
2279 /*
2280  * Debugging only
2281  */
2282 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2283 {
2284         vm_object_t object;
2285         int nl = 0;
2286         int c;
2287         for (object = TAILQ_FIRST(&vm_object_list);
2288                         object != NULL;
2289                         object = TAILQ_NEXT(object, object_list)) {
2290                 vm_pindex_t idx, fidx;
2291                 vm_pindex_t osize;
2292                 vm_paddr_t pa = -1, padiff;
2293                 int rcount;
2294                 vm_page_t m;
2295
2296                 if (object->type == OBJT_MARKER)
2297                         continue;
2298                 db_printf("new object: %p\n", (void *)object);
2299                 if ( nl > 18) {
2300                         c = cngetc();
2301                         if (c != ' ')
2302                                 return;
2303                         nl = 0;
2304                 }
2305                 nl++;
2306                 rcount = 0;
2307                 fidx = 0;
2308                 osize = object->size;
2309                 if (osize > 128)
2310                         osize = 128;
2311                 for (idx = 0; idx < osize; idx++) {
2312                         m = vm_page_lookup(object, idx);
2313                         if (m == NULL) {
2314                                 if (rcount) {
2315                                         db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2316                                                 (long)fidx, rcount, (long)pa);
2317                                         if ( nl > 18) {
2318                                                 c = cngetc();
2319                                                 if (c != ' ')
2320                                                         return;
2321                                                 nl = 0;
2322                                         }
2323                                         nl++;
2324                                         rcount = 0;
2325                                 }
2326                                 continue;
2327                         }
2328
2329                                 
2330                         if (rcount &&
2331                                 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2332                                 ++rcount;
2333                                 continue;
2334                         }
2335                         if (rcount) {
2336                                 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
2337                                 padiff >>= PAGE_SHIFT;
2338                                 padiff &= PQ_L2_MASK;
2339                                 if (padiff == 0) {
2340                                         pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
2341                                         ++rcount;
2342                                         continue;
2343                                 }
2344                                 db_printf(" index(%ld)run(%d)pa(0x%lx)",
2345                                         (long)fidx, rcount, (long)pa);
2346                                 db_printf("pd(%ld)\n", (long)padiff);
2347                                 if ( nl > 18) {
2348                                         c = cngetc();
2349                                         if (c != ' ')
2350                                                 return;
2351                                         nl = 0;
2352                                 }
2353                                 nl++;
2354                         }
2355                         fidx = idx;
2356                         pa = VM_PAGE_TO_PHYS(m);
2357                         rcount = 1;
2358                 }
2359                 if (rcount) {
2360                         db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2361                                 (long)fidx, rcount, (long)pa);
2362                         if ( nl > 18) {
2363                                 c = cngetc();
2364                                 if (c != ' ')
2365                                         return;
2366                                 nl = 0;
2367                         }
2368                         nl++;
2369                 }
2370         }
2371 }
2372 #endif /* DDB */