proc->thread stage 4: rework the VFS and DEVICE subsystems to take thread
[dragonfly.git] / sys / vm / vm_object.c
CommitLineData
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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: src/sys/vm/vm_object.c,v 1.171.2.8 2003/05/26 19:17:56 alc Exp $
dadab5e9 65 * $DragonFly: src/sys/vm/vm_object.c,v 1.3 2003/06/25 03:56:13 dillon Exp $
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66 */
67
68/*
69 * Virtual memory object module.
70 */
71
72#include <sys/param.h>
73#include <sys/systm.h>
74#include <sys/proc.h> /* for curproc, pageproc */
75#include <sys/vnode.h>
76#include <sys/vmmeter.h>
77#include <sys/mman.h>
78#include <sys/mount.h>
79#include <sys/kernel.h>
80#include <sys/sysctl.h>
81
82#include <vm/vm.h>
83#include <vm/vm_param.h>
84#include <vm/pmap.h>
85#include <vm/vm_map.h>
86#include <vm/vm_object.h>
87#include <vm/vm_page.h>
88#include <vm/vm_pageout.h>
89#include <vm/vm_pager.h>
90#include <vm/swap_pager.h>
91#include <vm/vm_kern.h>
92#include <vm/vm_extern.h>
93#include <vm/vm_zone.h>
94
95#define EASY_SCAN_FACTOR 8
96
97#define MSYNC_FLUSH_HARDSEQ 0x01
98#define MSYNC_FLUSH_SOFTSEQ 0x02
99
100static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ;
101SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags,
102 CTLFLAG_RW, &msync_flush_flags, 0, "");
103
104static void vm_object_qcollapse (vm_object_t object);
105static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags);
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
133struct object_q vm_object_list;
134#ifndef NULL_SIMPLELOCKS
135static struct simplelock vm_object_list_lock;
136#endif
137static long vm_object_count; /* count of all objects */
138vm_object_t kernel_object;
139vm_object_t kmem_object;
140static struct vm_object kernel_object_store;
141static struct vm_object kmem_object_store;
142extern int vm_pageout_page_count;
143
144static long object_collapses;
145static long object_bypasses;
146static int next_index;
147static vm_zone_t obj_zone;
148static struct vm_zone obj_zone_store;
149static int object_hash_rand;
150#define VM_OBJECTS_INIT 256
151static struct vm_object vm_objects_init[VM_OBJECTS_INIT];
152
153void
154_vm_object_allocate(type, size, object)
155 objtype_t type;
156 vm_size_t size;
157 vm_object_t object;
158{
159 int incr;
160 TAILQ_INIT(&object->memq);
161 LIST_INIT(&object->shadow_head);
162
163 object->type = type;
164 object->size = size;
165 object->ref_count = 1;
166 object->flags = 0;
167 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
168 vm_object_set_flag(object, OBJ_ONEMAPPING);
169 object->paging_in_progress = 0;
170 object->resident_page_count = 0;
171 object->shadow_count = 0;
172 object->pg_color = next_index;
173 if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
174 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
175 else
176 incr = size;
177 next_index = (next_index + incr) & PQ_L2_MASK;
178 object->handle = NULL;
179 object->backing_object = NULL;
180 object->backing_object_offset = (vm_ooffset_t) 0;
181 /*
182 * Try to generate a number that will spread objects out in the
183 * hash table. We 'wipe' new objects across the hash in 128 page
184 * increments plus 1 more to offset it a little more by the time
185 * it wraps around.
186 */
187 object->hash_rand = object_hash_rand - 129;
188
189 object->generation++;
190
191 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
192 vm_object_count++;
193 object_hash_rand = object->hash_rand;
194}
195
196/*
197 * vm_object_init:
198 *
199 * Initialize the VM objects module.
200 */
201void
202vm_object_init()
203{
204 TAILQ_INIT(&vm_object_list);
205 simple_lock_init(&vm_object_list_lock);
206 vm_object_count = 0;
207
208 kernel_object = &kernel_object_store;
209 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
210 kernel_object);
211
212 kmem_object = &kmem_object_store;
213 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
214 kmem_object);
215
216 obj_zone = &obj_zone_store;
217 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object),
218 vm_objects_init, VM_OBJECTS_INIT);
219}
220
221void
222vm_object_init2() {
223 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1);
224}
225
226/*
227 * vm_object_allocate:
228 *
229 * Returns a new object with the given size.
230 */
231
232vm_object_t
233vm_object_allocate(type, size)
234 objtype_t type;
235 vm_size_t size;
236{
237 vm_object_t result;
238
239 result = (vm_object_t) zalloc(obj_zone);
240
241 _vm_object_allocate(type, size, result);
242
243 return (result);
244}
245
246
247/*
248 * vm_object_reference:
249 *
250 * Gets another reference to the given object.
251 */
252void
253vm_object_reference(object)
254 vm_object_t object;
255{
256 if (object == NULL)
257 return;
258
259#if 0
260 /* object can be re-referenced during final cleaning */
261 KASSERT(!(object->flags & OBJ_DEAD),
262 ("vm_object_reference: attempting to reference dead obj"));
263#endif
264
265 object->ref_count++;
266 if (object->type == OBJT_VNODE) {
dadab5e9 267 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) {
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268 printf("vm_object_reference: delay in getting object\n");
269 }
270 }
271}
272
273void
274vm_object_vndeallocate(object)
275 vm_object_t object;
276{
277 struct vnode *vp = (struct vnode *) object->handle;
278
279 KASSERT(object->type == OBJT_VNODE,
280 ("vm_object_vndeallocate: not a vnode object"));
281 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
282#ifdef INVARIANTS
283 if (object->ref_count == 0) {
284 vprint("vm_object_vndeallocate", vp);
285 panic("vm_object_vndeallocate: bad object reference count");
286 }
287#endif
288
289 object->ref_count--;
290 if (object->ref_count == 0) {
291 vp->v_flag &= ~VTEXT;
292 vm_object_clear_flag(object, OBJ_OPT);
293 }
294 vrele(vp);
295}
296
297/*
298 * vm_object_deallocate:
299 *
300 * Release a reference to the specified object,
301 * gained either through a vm_object_allocate
302 * or a vm_object_reference call. When all references
303 * are gone, storage associated with this object
304 * may be relinquished.
305 *
306 * No object may be locked.
307 */
308void
309vm_object_deallocate(object)
310 vm_object_t object;
311{
312 vm_object_t temp;
313
314 while (object != NULL) {
315
316 if (object->type == OBJT_VNODE) {
317 vm_object_vndeallocate(object);
318 return;
319 }
320
321 if (object->ref_count == 0) {
322 panic("vm_object_deallocate: object deallocated too many times: %d", object->type);
323 } else if (object->ref_count > 2) {
324 object->ref_count--;
325 return;
326 }
327
328 /*
329 * Here on ref_count of one or two, which are special cases for
330 * objects.
331 */
332 if ((object->ref_count == 2) && (object->shadow_count == 0)) {
333 vm_object_set_flag(object, OBJ_ONEMAPPING);
334 object->ref_count--;
335 return;
336 } else if ((object->ref_count == 2) && (object->shadow_count == 1)) {
337 object->ref_count--;
338 if ((object->handle == NULL) &&
339 (object->type == OBJT_DEFAULT ||
340 object->type == OBJT_SWAP)) {
341 vm_object_t robject;
342
343 robject = LIST_FIRST(&object->shadow_head);
344 KASSERT(robject != NULL,
345 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
346 object->ref_count,
347 object->shadow_count));
348 if ((robject->handle == NULL) &&
349 (robject->type == OBJT_DEFAULT ||
350 robject->type == OBJT_SWAP)) {
351
352 robject->ref_count++;
353
354 while (
355 robject->paging_in_progress ||
356 object->paging_in_progress
357 ) {
358 vm_object_pip_sleep(robject, "objde1");
359 vm_object_pip_sleep(object, "objde2");
360 }
361
362 if (robject->ref_count == 1) {
363 robject->ref_count--;
364 object = robject;
365 goto doterm;
366 }
367
368 object = robject;
369 vm_object_collapse(object);
370 continue;
371 }
372 }
373
374 return;
375
376 } else {
377 object->ref_count--;
378 if (object->ref_count != 0)
379 return;
380 }
381
382doterm:
383
384 temp = object->backing_object;
385 if (temp) {
386 LIST_REMOVE(object, shadow_list);
387 temp->shadow_count--;
388 if (temp->ref_count == 0)
389 vm_object_clear_flag(temp, OBJ_OPT);
390 temp->generation++;
391 object->backing_object = NULL;
392 }
393
394 /*
395 * Don't double-terminate, we could be in a termination
396 * recursion due to the terminate having to sync data
397 * to disk.
398 */
399 if ((object->flags & OBJ_DEAD) == 0)
400 vm_object_terminate(object);
401 object = temp;
402 }
403}
404
405/*
406 * vm_object_terminate actually destroys the specified object, freeing
407 * up all previously used resources.
408 *
409 * The object must be locked.
410 * This routine may block.
411 */
412void
413vm_object_terminate(object)
414 vm_object_t object;
415{
416 vm_page_t p;
417 int s;
418
419 /*
420 * Make sure no one uses us.
421 */
422 vm_object_set_flag(object, OBJ_DEAD);
423
424 /*
425 * wait for the pageout daemon to be done with the object
426 */
427 vm_object_pip_wait(object, "objtrm");
428
429 KASSERT(!object->paging_in_progress,
430 ("vm_object_terminate: pageout in progress"));
431
432 /*
433 * Clean and free the pages, as appropriate. All references to the
434 * object are gone, so we don't need to lock it.
435 */
436 if (object->type == OBJT_VNODE) {
437 struct vnode *vp;
438
439 /*
440 * Freeze optimized copies.
441 */
442 vm_freeze_copyopts(object, 0, object->size);
443
444 /*
445 * Clean pages and flush buffers.
446 */
447 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
448
449 vp = (struct vnode *) object->handle;
450 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
451 }
452
453 /*
454 * Wait for any I/O to complete, after which there had better not
455 * be any references left on the object.
456 */
457 vm_object_pip_wait(object, "objtrm");
458
459 if (object->ref_count != 0)
460 panic("vm_object_terminate: object with references, ref_count=%d", object->ref_count);
461
462 /*
463 * Now free any remaining pages. For internal objects, this also
464 * removes them from paging queues. Don't free wired pages, just
465 * remove them from the object.
466 */
467 s = splvm();
468 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
469 if (p->busy || (p->flags & PG_BUSY))
470 panic("vm_object_terminate: freeing busy page %p\n", p);
471 if (p->wire_count == 0) {
472 vm_page_busy(p);
473 vm_page_free(p);
474 cnt.v_pfree++;
475 } else {
476 vm_page_busy(p);
477 vm_page_remove(p);
478 }
479 }
480 splx(s);
481
482 /*
483 * Let the pager know object is dead.
484 */
485 vm_pager_deallocate(object);
486
487 /*
488 * Remove the object from the global object list.
489 */
490 simple_lock(&vm_object_list_lock);
491 TAILQ_REMOVE(&vm_object_list, object, object_list);
492 simple_unlock(&vm_object_list_lock);
493
494 wakeup(object);
495
496 /*
497 * Free the space for the object.
498 */
499 zfree(obj_zone, object);
500}
501
502/*
503 * vm_object_page_clean
504 *
505 * Clean all dirty pages in the specified range of object. Leaves page
506 * on whatever queue it is currently on. If NOSYNC is set then do not
507 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
508 * leaving the object dirty.
509 *
510 * When stuffing pages asynchronously, allow clustering. XXX we need a
511 * synchronous clustering mode implementation.
512 *
513 * Odd semantics: if start == end, we clean everything.
514 *
515 * The object must be locked.
516 */
517
518void
519vm_object_page_clean(object, start, end, flags)
520 vm_object_t object;
521 vm_pindex_t start;
522 vm_pindex_t end;
523 int flags;
524{
525 vm_page_t p, np;
526 vm_offset_t tstart, tend;
527 vm_pindex_t pi;
528 struct vnode *vp;
529 int clearobjflags;
530 int pagerflags;
531 int curgeneration;
532
533 if (object->type != OBJT_VNODE ||
534 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
535 return;
536
537 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
538 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
539
540 vp = object->handle;
541
542 vm_object_set_flag(object, OBJ_CLEANING);
543
544 /*
545 * Handle 'entire object' case
546 */
547 tstart = start;
548 if (end == 0) {
549 tend = object->size;
550 } else {
551 tend = end;
552 }
553
554 /*
555 * If the caller is smart and only msync()s a range he knows is
556 * dirty, we may be able to avoid an object scan. This results in
557 * a phenominal improvement in performance. We cannot do this
558 * as a matter of course because the object may be huge - e.g.
559 * the size might be in the gigabytes or terrabytes.
560 */
561 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
562 vm_offset_t tscan;
563 int scanlimit;
564 int scanreset;
565
566 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
567 if (scanreset < 16)
568 scanreset = 16;
569 pagerflags |= VM_PAGER_IGNORE_CLEANCHK;
570
571 scanlimit = scanreset;
572 tscan = tstart;
573 while (tscan < tend) {
574 curgeneration = object->generation;
575 p = vm_page_lookup(object, tscan);
576 if (p == NULL || p->valid == 0 ||
577 (p->queue - p->pc) == PQ_CACHE) {
578 if (--scanlimit == 0)
579 break;
580 ++tscan;
581 continue;
582 }
583 vm_page_test_dirty(p);
584 if ((p->dirty & p->valid) == 0) {
585 if (--scanlimit == 0)
586 break;
587 ++tscan;
588 continue;
589 }
590 /*
591 * If we have been asked to skip nosync pages and
592 * this is a nosync page, we can't continue.
593 */
594 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
595 if (--scanlimit == 0)
596 break;
597 ++tscan;
598 continue;
599 }
600 scanlimit = scanreset;
601
602 /*
603 * This returns 0 if it was unable to busy the first
604 * page (i.e. had to sleep).
605 */
606 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
607 }
608
609 /*
610 * If everything was dirty and we flushed it successfully,
611 * and the requested range is not the entire object, we
612 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
613 * return immediately.
614 */
615 if (tscan >= tend && (tstart || tend < object->size)) {
616 vm_object_clear_flag(object, OBJ_CLEANING);
617 return;
618 }
619 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK;
620 }
621
622 /*
623 * Generally set CLEANCHK interlock and make the page read-only so
624 * we can then clear the object flags.
625 *
626 * However, if this is a nosync mmap then the object is likely to
627 * stay dirty so do not mess with the page and do not clear the
628 * object flags.
629 */
630
631 clearobjflags = 1;
632
633 for(p = TAILQ_FIRST(&object->memq); p; p = TAILQ_NEXT(p, listq)) {
634 vm_page_flag_set(p, PG_CLEANCHK);
635 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
636 clearobjflags = 0;
637 else
638 vm_page_protect(p, VM_PROT_READ);
639 }
640
641 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
642 struct vnode *vp;
643
644 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
645 if (object->type == OBJT_VNODE &&
646 (vp = (struct vnode *)object->handle) != NULL) {
647 if (vp->v_flag & VOBJDIRTY) {
648 simple_lock(&vp->v_interlock);
649 vp->v_flag &= ~VOBJDIRTY;
650 simple_unlock(&vp->v_interlock);
651 }
652 }
653 }
654
655rescan:
656 curgeneration = object->generation;
657
658 for(p = TAILQ_FIRST(&object->memq); p; p = np) {
659 int n;
660
661 np = TAILQ_NEXT(p, listq);
662
663again:
664 pi = p->pindex;
665 if (((p->flags & PG_CLEANCHK) == 0) ||
666 (pi < tstart) || (pi >= tend) ||
667 (p->valid == 0) ||
668 ((p->queue - p->pc) == PQ_CACHE)) {
669 vm_page_flag_clear(p, PG_CLEANCHK);
670 continue;
671 }
672
673 vm_page_test_dirty(p);
674 if ((p->dirty & p->valid) == 0) {
675 vm_page_flag_clear(p, PG_CLEANCHK);
676 continue;
677 }
678
679 /*
680 * If we have been asked to skip nosync pages and this is a
681 * nosync page, skip it. Note that the object flags were
682 * not cleared in this case so we do not have to set them.
683 */
684 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
685 vm_page_flag_clear(p, PG_CLEANCHK);
686 continue;
687 }
688
689 n = vm_object_page_collect_flush(object, p,
690 curgeneration, pagerflags);
691 if (n == 0)
692 goto rescan;
693 if (object->generation != curgeneration)
694 goto rescan;
695
696 /*
697 * Try to optimize the next page. If we can't we pick up
698 * our (random) scan where we left off.
699 */
700 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
701 if ((p = vm_page_lookup(object, pi + n)) != NULL)
702 goto again;
703 }
704 }
705
706#if 0
707 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
708#endif
709
710 vm_object_clear_flag(object, OBJ_CLEANING);
711 return;
712}
713
714static int
715vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
716{
717 int runlen;
718 int s;
719 int maxf;
720 int chkb;
721 int maxb;
722 int i;
723 vm_pindex_t pi;
724 vm_page_t maf[vm_pageout_page_count];
725 vm_page_t mab[vm_pageout_page_count];
726 vm_page_t ma[vm_pageout_page_count];
727
728 s = splvm();
729 pi = p->pindex;
730 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) {
731 if (object->generation != curgeneration) {
732 splx(s);
733 return(0);
734 }
735 }
736
737 maxf = 0;
738 for(i = 1; i < vm_pageout_page_count; i++) {
739 vm_page_t tp;
740
741 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
742 if ((tp->flags & PG_BUSY) ||
743 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
744 (tp->flags & PG_CLEANCHK) == 0) ||
745 (tp->busy != 0))
746 break;
747 if((tp->queue - tp->pc) == PQ_CACHE) {
748 vm_page_flag_clear(tp, PG_CLEANCHK);
749 break;
750 }
751 vm_page_test_dirty(tp);
752 if ((tp->dirty & tp->valid) == 0) {
753 vm_page_flag_clear(tp, PG_CLEANCHK);
754 break;
755 }
756 maf[ i - 1 ] = tp;
757 maxf++;
758 continue;
759 }
760 break;
761 }
762
763 maxb = 0;
764 chkb = vm_pageout_page_count - maxf;
765 if (chkb) {
766 for(i = 1; i < chkb;i++) {
767 vm_page_t tp;
768
769 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
770 if ((tp->flags & PG_BUSY) ||
771 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
772 (tp->flags & PG_CLEANCHK) == 0) ||
773 (tp->busy != 0))
774 break;
775 if((tp->queue - tp->pc) == PQ_CACHE) {
776 vm_page_flag_clear(tp, PG_CLEANCHK);
777 break;
778 }
779 vm_page_test_dirty(tp);
780 if ((tp->dirty & tp->valid) == 0) {
781 vm_page_flag_clear(tp, PG_CLEANCHK);
782 break;
783 }
784 mab[ i - 1 ] = tp;
785 maxb++;
786 continue;
787 }
788 break;
789 }
790 }
791
792 for(i = 0; i < maxb; i++) {
793 int index = (maxb - i) - 1;
794 ma[index] = mab[i];
795 vm_page_flag_clear(ma[index], PG_CLEANCHK);
796 }
797 vm_page_flag_clear(p, PG_CLEANCHK);
798 ma[maxb] = p;
799 for(i = 0; i < maxf; i++) {
800 int index = (maxb + i) + 1;
801 ma[index] = maf[i];
802 vm_page_flag_clear(ma[index], PG_CLEANCHK);
803 }
804 runlen = maxb + maxf + 1;
805
806 splx(s);
807 vm_pageout_flush(ma, runlen, pagerflags);
808 for (i = 0; i < runlen; i++) {
809 if (ma[i]->valid & ma[i]->dirty) {
810 vm_page_protect(ma[i], VM_PROT_READ);
811 vm_page_flag_set(ma[i], PG_CLEANCHK);
812
813 /*
814 * maxf will end up being the actual number of pages
815 * we wrote out contiguously, non-inclusive of the
816 * first page. We do not count look-behind pages.
817 */
818 if (i >= maxb + 1 && (maxf > i - maxb - 1))
819 maxf = i - maxb - 1;
820 }
821 }
822 return(maxf + 1);
823}
824
825#ifdef not_used
826/* XXX I cannot tell if this should be an exported symbol */
827/*
828 * vm_object_deactivate_pages
829 *
830 * Deactivate all pages in the specified object. (Keep its pages
831 * in memory even though it is no longer referenced.)
832 *
833 * The object must be locked.
834 */
835static void
836vm_object_deactivate_pages(object)
837 vm_object_t object;
838{
839 vm_page_t p, next;
840
841 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
842 next = TAILQ_NEXT(p, listq);
843 vm_page_deactivate(p);
844 }
845}
846#endif
847
848/*
849 * Same as vm_object_pmap_copy, except range checking really
850 * works, and is meant for small sections of an object.
851 *
852 * This code protects resident pages by making them read-only
853 * and is typically called on a fork or split when a page
854 * is converted to copy-on-write.
855 *
856 * NOTE: If the page is already at VM_PROT_NONE, calling
857 * vm_page_protect will have no effect.
858 */
859
860void
861vm_object_pmap_copy_1(object, start, end)
862 vm_object_t object;
863 vm_pindex_t start;
864 vm_pindex_t end;
865{
866 vm_pindex_t idx;
867 vm_page_t p;
868
869 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0)
870 return;
871
872 for (idx = start; idx < end; idx++) {
873 p = vm_page_lookup(object, idx);
874 if (p == NULL)
875 continue;
876 vm_page_protect(p, VM_PROT_READ);
877 }
878}
879
880/*
881 * vm_object_pmap_remove:
882 *
883 * Removes all physical pages in the specified
884 * object range from all physical maps.
885 *
886 * The object must *not* be locked.
887 */
888void
889vm_object_pmap_remove(object, start, end)
890 vm_object_t object;
891 vm_pindex_t start;
892 vm_pindex_t end;
893{
894 vm_page_t p;
895
896 if (object == NULL)
897 return;
898 for (p = TAILQ_FIRST(&object->memq);
899 p != NULL;
900 p = TAILQ_NEXT(p, listq)) {
901 if (p->pindex >= start && p->pindex < end)
902 vm_page_protect(p, VM_PROT_NONE);
903 }
904 if ((start == 0) && (object->size == end))
905 vm_object_clear_flag(object, OBJ_WRITEABLE);
906}
907
908/*
909 * vm_object_madvise:
910 *
911 * Implements the madvise function at the object/page level.
912 *
913 * MADV_WILLNEED (any object)
914 *
915 * Activate the specified pages if they are resident.
916 *
917 * MADV_DONTNEED (any object)
918 *
919 * Deactivate the specified pages if they are resident.
920 *
921 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
922 * OBJ_ONEMAPPING only)
923 *
924 * Deactivate and clean the specified pages if they are
925 * resident. This permits the process to reuse the pages
926 * without faulting or the kernel to reclaim the pages
927 * without I/O.
928 */
929void
930vm_object_madvise(object, pindex, count, advise)
931 vm_object_t object;
932 vm_pindex_t pindex;
933 int count;
934 int advise;
935{
936 vm_pindex_t end, tpindex;
937 vm_object_t tobject;
938 vm_page_t m;
939
940 if (object == NULL)
941 return;
942
943 end = pindex + count;
944
945 /*
946 * Locate and adjust resident pages
947 */
948
949 for (; pindex < end; pindex += 1) {
950relookup:
951 tobject = object;
952 tpindex = pindex;
953shadowlookup:
954 /*
955 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
956 * and those pages must be OBJ_ONEMAPPING.
957 */
958 if (advise == MADV_FREE) {
959 if ((tobject->type != OBJT_DEFAULT &&
960 tobject->type != OBJT_SWAP) ||
961 (tobject->flags & OBJ_ONEMAPPING) == 0) {
962 continue;
963 }
964 }
965
966 m = vm_page_lookup(tobject, tpindex);
967
968 if (m == NULL) {
969 /*
970 * There may be swap even if there is no backing page
971 */
972 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
973 swap_pager_freespace(tobject, tpindex, 1);
974
975 /*
976 * next object
977 */
978 tobject = tobject->backing_object;
979 if (tobject == NULL)
980 continue;
981 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
982 goto shadowlookup;
983 }
984
985 /*
986 * If the page is busy or not in a normal active state,
987 * we skip it. If the page is not managed there are no
988 * page queues to mess with. Things can break if we mess
989 * with pages in any of the below states.
990 */
991 if (
992 m->hold_count ||
993 m->wire_count ||
994 (m->flags & PG_UNMANAGED) ||
995 m->valid != VM_PAGE_BITS_ALL
996 ) {
997 continue;
998 }
999
1000 if (vm_page_sleep_busy(m, TRUE, "madvpo"))
1001 goto relookup;
1002
1003 if (advise == MADV_WILLNEED) {
1004 vm_page_activate(m);
1005 } else if (advise == MADV_DONTNEED) {
1006 vm_page_dontneed(m);
1007 } else if (advise == MADV_FREE) {
1008 /*
1009 * Mark the page clean. This will allow the page
1010 * to be freed up by the system. However, such pages
1011 * are often reused quickly by malloc()/free()
1012 * so we do not do anything that would cause
1013 * a page fault if we can help it.
1014 *
1015 * Specifically, we do not try to actually free
1016 * the page now nor do we try to put it in the
1017 * cache (which would cause a page fault on reuse).
1018 *
1019 * But we do make the page is freeable as we
1020 * can without actually taking the step of unmapping
1021 * it.
1022 */
1023 pmap_clear_modify(m);
1024 m->dirty = 0;
1025 m->act_count = 0;
1026 vm_page_dontneed(m);
1027 if (tobject->type == OBJT_SWAP)
1028 swap_pager_freespace(tobject, tpindex, 1);
1029 }
1030 }
1031}
1032
1033/*
1034 * vm_object_shadow:
1035 *
1036 * Create a new object which is backed by the
1037 * specified existing object range. The source
1038 * object reference is deallocated.
1039 *
1040 * The new object and offset into that object
1041 * are returned in the source parameters.
1042 */
1043
1044void
1045vm_object_shadow(object, offset, length)
1046 vm_object_t *object; /* IN/OUT */
1047 vm_ooffset_t *offset; /* IN/OUT */
1048 vm_size_t length;
1049{
1050 vm_object_t source;
1051 vm_object_t result;
1052
1053 source = *object;
1054
1055 /*
1056 * Don't create the new object if the old object isn't shared.
1057 */
1058
1059 if (source != NULL &&
1060 source->ref_count == 1 &&
1061 source->handle == NULL &&
1062 (source->type == OBJT_DEFAULT ||
1063 source->type == OBJT_SWAP))
1064 return;
1065
1066 /*
1067 * Allocate a new object with the given length
1068 */
1069
1070 if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL)
1071 panic("vm_object_shadow: no object for shadowing");
1072
1073 /*
1074 * The new object shadows the source object, adding a reference to it.
1075 * Our caller changes his reference to point to the new object,
1076 * removing a reference to the source object. Net result: no change
1077 * of reference count.
1078 *
1079 * Try to optimize the result object's page color when shadowing
1080 * in order to maintain page coloring consistency in the combined
1081 * shadowed object.
1082 */
1083 result->backing_object = source;
1084 if (source) {
1085 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
1086 source->shadow_count++;
1087 source->generation++;
1088 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK;
1089 }
1090
1091 /*
1092 * Store the offset into the source object, and fix up the offset into
1093 * the new object.
1094 */
1095
1096 result->backing_object_offset = *offset;
1097
1098 /*
1099 * Return the new things
1100 */
1101
1102 *offset = 0;
1103 *object = result;
1104}
1105
1106#define OBSC_TEST_ALL_SHADOWED 0x0001
1107#define OBSC_COLLAPSE_NOWAIT 0x0002
1108#define OBSC_COLLAPSE_WAIT 0x0004
1109
1110static __inline int
1111vm_object_backing_scan(vm_object_t object, int op)
1112{
1113 int s;
1114 int r = 1;
1115 vm_page_t p;
1116 vm_object_t backing_object;
1117 vm_pindex_t backing_offset_index;
1118
1119 s = splvm();
1120
1121 backing_object = object->backing_object;
1122 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1123
1124 /*
1125 * Initial conditions
1126 */
1127
1128 if (op & OBSC_TEST_ALL_SHADOWED) {
1129 /*
1130 * We do not want to have to test for the existence of
1131 * swap pages in the backing object. XXX but with the
1132 * new swapper this would be pretty easy to do.
1133 *
1134 * XXX what about anonymous MAP_SHARED memory that hasn't
1135 * been ZFOD faulted yet? If we do not test for this, the
1136 * shadow test may succeed! XXX
1137 */
1138 if (backing_object->type != OBJT_DEFAULT) {
1139 splx(s);
1140 return(0);
1141 }
1142 }
1143 if (op & OBSC_COLLAPSE_WAIT) {
1144 vm_object_set_flag(backing_object, OBJ_DEAD);
1145 }
1146
1147 /*
1148 * Our scan
1149 */
1150
1151 p = TAILQ_FIRST(&backing_object->memq);
1152 while (p) {
1153 vm_page_t next = TAILQ_NEXT(p, listq);
1154 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1155
1156 if (op & OBSC_TEST_ALL_SHADOWED) {
1157 vm_page_t pp;
1158
1159 /*
1160 * Ignore pages outside the parent object's range
1161 * and outside the parent object's mapping of the
1162 * backing object.
1163 *
1164 * note that we do not busy the backing object's
1165 * page.
1166 */
1167
1168 if (
1169 p->pindex < backing_offset_index ||
1170 new_pindex >= object->size
1171 ) {
1172 p = next;
1173 continue;
1174 }
1175
1176 /*
1177 * See if the parent has the page or if the parent's
1178 * object pager has the page. If the parent has the
1179 * page but the page is not valid, the parent's
1180 * object pager must have the page.
1181 *
1182 * If this fails, the parent does not completely shadow
1183 * the object and we might as well give up now.
1184 */
1185
1186 pp = vm_page_lookup(object, new_pindex);
1187 if (
1188 (pp == NULL || pp->valid == 0) &&
1189 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1190 ) {
1191 r = 0;
1192 break;
1193 }
1194 }
1195
1196 /*
1197 * Check for busy page
1198 */
1199
1200 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1201 vm_page_t pp;
1202
1203 if (op & OBSC_COLLAPSE_NOWAIT) {
1204 if (
1205 (p->flags & PG_BUSY) ||
1206 !p->valid ||
1207 p->hold_count ||
1208 p->wire_count ||
1209 p->busy
1210 ) {
1211 p = next;
1212 continue;
1213 }
1214 } else if (op & OBSC_COLLAPSE_WAIT) {
1215 if (vm_page_sleep_busy(p, TRUE, "vmocol")) {
1216 /*
1217 * If we slept, anything could have
1218 * happened. Since the object is
1219 * marked dead, the backing offset
1220 * should not have changed so we
1221 * just restart our scan.
1222 */
1223 p = TAILQ_FIRST(&backing_object->memq);
1224 continue;
1225 }
1226 }
1227
1228 /*
1229 * Busy the page
1230 */
1231 vm_page_busy(p);
1232
1233 KASSERT(
1234 p->object == backing_object,
1235 ("vm_object_qcollapse(): object mismatch")
1236 );
1237
1238 /*
1239 * Destroy any associated swap
1240 */
1241 if (backing_object->type == OBJT_SWAP) {
1242 swap_pager_freespace(
1243 backing_object,
1244 p->pindex,
1245 1
1246 );
1247 }
1248
1249 if (
1250 p->pindex < backing_offset_index ||
1251 new_pindex >= object->size
1252 ) {
1253 /*
1254 * Page is out of the parent object's range, we
1255 * can simply destroy it.
1256 */
1257 vm_page_protect(p, VM_PROT_NONE);
1258 vm_page_free(p);
1259 p = next;
1260 continue;
1261 }
1262
1263 pp = vm_page_lookup(object, new_pindex);
1264 if (
1265 pp != NULL ||
1266 vm_pager_has_page(object, new_pindex, NULL, NULL)
1267 ) {
1268 /*
1269 * page already exists in parent OR swap exists
1270 * for this location in the parent. Destroy
1271 * the original page from the backing object.
1272 *
1273 * Leave the parent's page alone
1274 */
1275 vm_page_protect(p, VM_PROT_NONE);
1276 vm_page_free(p);
1277 p = next;
1278 continue;
1279 }
1280
1281 /*
1282 * Page does not exist in parent, rename the
1283 * page from the backing object to the main object.
1284 *
1285 * If the page was mapped to a process, it can remain
1286 * mapped through the rename.
1287 */
1288 if ((p->queue - p->pc) == PQ_CACHE)
1289 vm_page_deactivate(p);
1290
1291 vm_page_rename(p, object, new_pindex);
1292 /* page automatically made dirty by rename */
1293 }
1294 p = next;
1295 }
1296 splx(s);
1297 return(r);
1298}
1299
1300
1301/*
1302 * this version of collapse allows the operation to occur earlier and
1303 * when paging_in_progress is true for an object... This is not a complete
1304 * operation, but should plug 99.9% of the rest of the leaks.
1305 */
1306static void
1307vm_object_qcollapse(object)
1308 vm_object_t object;
1309{
1310 vm_object_t backing_object = object->backing_object;
1311
1312 if (backing_object->ref_count != 1)
1313 return;
1314
1315 backing_object->ref_count += 2;
1316
1317 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1318
1319 backing_object->ref_count -= 2;
1320}
1321
1322/*
1323 * vm_object_collapse:
1324 *
1325 * Collapse an object with the object backing it.
1326 * Pages in the backing object are moved into the
1327 * parent, and the backing object is deallocated.
1328 */
1329void
1330vm_object_collapse(object)
1331 vm_object_t object;
1332{
1333 while (TRUE) {
1334 vm_object_t backing_object;
1335
1336 /*
1337 * Verify that the conditions are right for collapse:
1338 *
1339 * The object exists and the backing object exists.
1340 */
1341 if (object == NULL)
1342 break;
1343
1344 if ((backing_object = object->backing_object) == NULL)
1345 break;
1346
1347 /*
1348 * we check the backing object first, because it is most likely
1349 * not collapsable.
1350 */
1351 if (backing_object->handle != NULL ||
1352 (backing_object->type != OBJT_DEFAULT &&
1353 backing_object->type != OBJT_SWAP) ||
1354 (backing_object->flags & OBJ_DEAD) ||
1355 object->handle != NULL ||
1356 (object->type != OBJT_DEFAULT &&
1357 object->type != OBJT_SWAP) ||
1358 (object->flags & OBJ_DEAD)) {
1359 break;
1360 }
1361
1362 if (
1363 object->paging_in_progress != 0 ||
1364 backing_object->paging_in_progress != 0
1365 ) {
1366 vm_object_qcollapse(object);
1367 break;
1368 }
1369
1370 /*
1371 * We know that we can either collapse the backing object (if
1372 * the parent is the only reference to it) or (perhaps) have
1373 * the parent bypass the object if the parent happens to shadow
1374 * all the resident pages in the entire backing object.
1375 *
1376 * This is ignoring pager-backed pages such as swap pages.
1377 * vm_object_backing_scan fails the shadowing test in this
1378 * case.
1379 */
1380
1381 if (backing_object->ref_count == 1) {
1382 /*
1383 * If there is exactly one reference to the backing
1384 * object, we can collapse it into the parent.
1385 */
1386
1387 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1388
1389 /*
1390 * Move the pager from backing_object to object.
1391 */
1392
1393 if (backing_object->type == OBJT_SWAP) {
1394 vm_object_pip_add(backing_object, 1);
1395
1396 /*
1397 * scrap the paging_offset junk and do a
1398 * discrete copy. This also removes major
1399 * assumptions about how the swap-pager
1400 * works from where it doesn't belong. The
1401 * new swapper is able to optimize the
1402 * destroy-source case.
1403 */
1404
1405 vm_object_pip_add(object, 1);
1406 swap_pager_copy(
1407 backing_object,
1408 object,
1409 OFF_TO_IDX(object->backing_object_offset), TRUE);
1410 vm_object_pip_wakeup(object);
1411
1412 vm_object_pip_wakeup(backing_object);
1413 }
1414 /*
1415 * Object now shadows whatever backing_object did.
1416 * Note that the reference to
1417 * backing_object->backing_object moves from within
1418 * backing_object to within object.
1419 */
1420
1421 LIST_REMOVE(object, shadow_list);
1422 object->backing_object->shadow_count--;
1423 object->backing_object->generation++;
1424 if (backing_object->backing_object) {
1425 LIST_REMOVE(backing_object, shadow_list);
1426 backing_object->backing_object->shadow_count--;
1427 backing_object->backing_object->generation++;
1428 }
1429 object->backing_object = backing_object->backing_object;
1430 if (object->backing_object) {
1431 LIST_INSERT_HEAD(
1432 &object->backing_object->shadow_head,
1433 object,
1434 shadow_list
1435 );
1436 object->backing_object->shadow_count++;
1437 object->backing_object->generation++;
1438 }
1439
1440 object->backing_object_offset +=
1441 backing_object->backing_object_offset;
1442
1443 /*
1444 * Discard backing_object.
1445 *
1446 * Since the backing object has no pages, no pager left,
1447 * and no object references within it, all that is
1448 * necessary is to dispose of it.
1449 */
1450
1451 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1452 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
1453 TAILQ_REMOVE(
1454 &vm_object_list,
1455 backing_object,
1456 object_list
1457 );
1458 vm_object_count--;
1459
1460 zfree(obj_zone, backing_object);
1461
1462 object_collapses++;
1463 } else {
1464 vm_object_t new_backing_object;
1465
1466 /*
1467 * If we do not entirely shadow the backing object,
1468 * there is nothing we can do so we give up.
1469 */
1470
1471 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1472 break;
1473 }
1474
1475 /*
1476 * Make the parent shadow the next object in the
1477 * chain. Deallocating backing_object will not remove
1478 * it, since its reference count is at least 2.
1479 */
1480
1481 LIST_REMOVE(object, shadow_list);
1482 backing_object->shadow_count--;
1483 backing_object->generation++;
1484
1485 new_backing_object = backing_object->backing_object;
1486 if ((object->backing_object = new_backing_object) != NULL) {
1487 vm_object_reference(new_backing_object);
1488 LIST_INSERT_HEAD(
1489 &new_backing_object->shadow_head,
1490 object,
1491 shadow_list
1492 );
1493 new_backing_object->shadow_count++;
1494 new_backing_object->generation++;
1495 object->backing_object_offset +=
1496 backing_object->backing_object_offset;
1497 }
1498
1499 /*
1500 * Drop the reference count on backing_object. Since
1501 * its ref_count was at least 2, it will not vanish;
1502 * so we don't need to call vm_object_deallocate, but
1503 * we do anyway.
1504 */
1505 vm_object_deallocate(backing_object);
1506 object_bypasses++;
1507 }
1508
1509 /*
1510 * Try again with this object's new backing object.
1511 */
1512 }
1513}
1514
1515/*
1516 * vm_object_page_remove: [internal]
1517 *
1518 * Removes all physical pages in the specified
1519 * object range from the object's list of pages.
1520 *
1521 * The object must be locked.
1522 */
1523void
1524vm_object_page_remove(object, start, end, clean_only)
1525 vm_object_t object;
1526 vm_pindex_t start;
1527 vm_pindex_t end;
1528 boolean_t clean_only;
1529{
1530 vm_page_t p, next;
1531 unsigned int size;
1532 int all;
1533
1534 if (object == NULL ||
1535 object->resident_page_count == 0)
1536 return;
1537
1538 all = ((end == 0) && (start == 0));
1539
1540 /*
1541 * Since physically-backed objects do not use managed pages, we can't
1542 * remove pages from the object (we must instead remove the page
1543 * references, and then destroy the object).
1544 */
1545 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object"));
1546
1547 vm_object_pip_add(object, 1);
1548again:
1549 size = end - start;
1550 if (all || size > object->resident_page_count / 4) {
1551 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) {
1552 next = TAILQ_NEXT(p, listq);
1553 if (all || ((start <= p->pindex) && (p->pindex < end))) {
1554 if (p->wire_count != 0) {
1555 vm_page_protect(p, VM_PROT_NONE);
1556 if (!clean_only)
1557 p->valid = 0;
1558 continue;
1559 }
1560
1561 /*
1562 * The busy flags are only cleared at
1563 * interrupt -- minimize the spl transitions
1564 */
1565
1566 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1567 goto again;
1568
1569 if (clean_only && p->valid) {
1570 vm_page_test_dirty(p);
1571 if (p->valid & p->dirty)
1572 continue;
1573 }
1574
1575 vm_page_busy(p);
1576 vm_page_protect(p, VM_PROT_NONE);
1577 vm_page_free(p);
1578 }
1579 }
1580 } else {
1581 while (size > 0) {
1582 if ((p = vm_page_lookup(object, start)) != 0) {
1583
1584 if (p->wire_count != 0) {
1585 vm_page_protect(p, VM_PROT_NONE);
1586 if (!clean_only)
1587 p->valid = 0;
1588 start += 1;
1589 size -= 1;
1590 continue;
1591 }
1592
1593 /*
1594 * The busy flags are only cleared at
1595 * interrupt -- minimize the spl transitions
1596 */
1597 if (vm_page_sleep_busy(p, TRUE, "vmopar"))
1598 goto again;
1599
1600 if (clean_only && p->valid) {
1601 vm_page_test_dirty(p);
1602 if (p->valid & p->dirty) {
1603 start += 1;
1604 size -= 1;
1605 continue;
1606 }
1607 }
1608
1609 vm_page_busy(p);
1610 vm_page_protect(p, VM_PROT_NONE);
1611 vm_page_free(p);
1612 }
1613 start += 1;
1614 size -= 1;
1615 }
1616 }
1617 vm_object_pip_wakeup(object);
1618}
1619
1620/*
1621 * Routine: vm_object_coalesce
1622 * Function: Coalesces two objects backing up adjoining
1623 * regions of memory into a single object.
1624 *
1625 * returns TRUE if objects were combined.
1626 *
1627 * NOTE: Only works at the moment if the second object is NULL -
1628 * if it's not, which object do we lock first?
1629 *
1630 * Parameters:
1631 * prev_object First object to coalesce
1632 * prev_offset Offset into prev_object
1633 * next_object Second object into coalesce
1634 * next_offset Offset into next_object
1635 *
1636 * prev_size Size of reference to prev_object
1637 * next_size Size of reference to next_object
1638 *
1639 * Conditions:
1640 * The object must *not* be locked.
1641 */
1642boolean_t
1643vm_object_coalesce(prev_object, prev_pindex, prev_size, next_size)
1644 vm_object_t prev_object;
1645 vm_pindex_t prev_pindex;
1646 vm_size_t prev_size, next_size;
1647{
1648 vm_pindex_t next_pindex;
1649
1650 if (prev_object == NULL) {
1651 return (TRUE);
1652 }
1653
1654 if (prev_object->type != OBJT_DEFAULT &&
1655 prev_object->type != OBJT_SWAP) {
1656 return (FALSE);
1657 }
1658
1659 /*
1660 * Try to collapse the object first
1661 */
1662 vm_object_collapse(prev_object);
1663
1664 /*
1665 * Can't coalesce if: . more than one reference . paged out . shadows
1666 * another object . has a copy elsewhere (any of which mean that the
1667 * pages not mapped to prev_entry may be in use anyway)
1668 */
1669
1670 if (prev_object->backing_object != NULL) {
1671 return (FALSE);
1672 }
1673
1674 prev_size >>= PAGE_SHIFT;
1675 next_size >>= PAGE_SHIFT;
1676 next_pindex = prev_pindex + prev_size;
1677
1678 if ((prev_object->ref_count > 1) &&
1679 (prev_object->size != next_pindex)) {
1680 return (FALSE);
1681 }
1682
1683 /*
1684 * Remove any pages that may still be in the object from a previous
1685 * deallocation.
1686 */
1687 if (next_pindex < prev_object->size) {
1688 vm_object_page_remove(prev_object,
1689 next_pindex,
1690 next_pindex + next_size, FALSE);
1691 if (prev_object->type == OBJT_SWAP)
1692 swap_pager_freespace(prev_object,
1693 next_pindex, next_size);
1694 }
1695
1696 /*
1697 * Extend the object if necessary.
1698 */
1699 if (next_pindex + next_size > prev_object->size)
1700 prev_object->size = next_pindex + next_size;
1701
1702 return (TRUE);
1703}
1704
1705void
1706vm_object_set_writeable_dirty(vm_object_t object)
1707{
1708 struct vnode *vp;
1709
1710 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1711 if (object->type == OBJT_VNODE &&
1712 (vp = (struct vnode *)object->handle) != NULL) {
1713 if ((vp->v_flag & VOBJDIRTY) == 0) {
1714 simple_lock(&vp->v_interlock);
1715 vp->v_flag |= VOBJDIRTY;
1716 simple_unlock(&vp->v_interlock);
1717 }
1718 }
1719}
1720
1721
1722
1723#include "opt_ddb.h"
1724#ifdef DDB
1725#include <sys/kernel.h>
1726
1727#include <sys/cons.h>
1728
1729#include <ddb/ddb.h>
1730
1731static int _vm_object_in_map __P((vm_map_t map, vm_object_t object,
1732 vm_map_entry_t entry));
1733static int vm_object_in_map __P((vm_object_t object));
1734
1735static int
1736_vm_object_in_map(map, object, entry)
1737 vm_map_t map;
1738 vm_object_t object;
1739 vm_map_entry_t entry;
1740{
1741 vm_map_t tmpm;
1742 vm_map_entry_t tmpe;
1743 vm_object_t obj;
1744 int entcount;
1745
1746 if (map == 0)
1747 return 0;
1748
1749 if (entry == 0) {
1750 tmpe = map->header.next;
1751 entcount = map->nentries;
1752 while (entcount-- && (tmpe != &map->header)) {
1753 if( _vm_object_in_map(map, object, tmpe)) {
1754 return 1;
1755 }
1756 tmpe = tmpe->next;
1757 }
1758 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1759 tmpm = entry->object.sub_map;
1760 tmpe = tmpm->header.next;
1761 entcount = tmpm->nentries;
1762 while (entcount-- && tmpe != &tmpm->header) {
1763 if( _vm_object_in_map(tmpm, object, tmpe)) {
1764 return 1;
1765 }
1766 tmpe = tmpe->next;
1767 }
1768 } else if ((obj = entry->object.vm_object) != NULL) {
1769 for(; obj; obj=obj->backing_object)
1770 if( obj == object) {
1771 return 1;
1772 }
1773 }
1774 return 0;
1775}
1776
1777static int
1778vm_object_in_map( object)
1779 vm_object_t object;
1780{
1781 struct proc *p;
1782 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) {
1783 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1784 continue;
1785 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0))
1786 return 1;
1787 }
1788 if( _vm_object_in_map( kernel_map, object, 0))
1789 return 1;
1790 if( _vm_object_in_map( kmem_map, object, 0))
1791 return 1;
1792 if( _vm_object_in_map( pager_map, object, 0))
1793 return 1;
1794 if( _vm_object_in_map( buffer_map, object, 0))
1795 return 1;
1796 if( _vm_object_in_map( mb_map, object, 0))
1797 return 1;
1798 return 0;
1799}
1800
1801DB_SHOW_COMMAND(vmochk, vm_object_check)
1802{
1803 vm_object_t object;
1804
1805 /*
1806 * make sure that internal objs are in a map somewhere
1807 * and none have zero ref counts.
1808 */
1809 for (object = TAILQ_FIRST(&vm_object_list);
1810 object != NULL;
1811 object = TAILQ_NEXT(object, object_list)) {
1812 if (object->handle == NULL &&
1813 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
1814 if (object->ref_count == 0) {
1815 db_printf("vmochk: internal obj has zero ref count: %ld\n",
1816 (long)object->size);
1817 }
1818 if (!vm_object_in_map(object)) {
1819 db_printf(
1820 "vmochk: internal obj is not in a map: "
1821 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
1822 object->ref_count, (u_long)object->size,
1823 (u_long)object->size,
1824 (void *)object->backing_object);
1825 }
1826 }
1827 }
1828}
1829
1830/*
1831 * vm_object_print: [ debug ]
1832 */
1833DB_SHOW_COMMAND(object, vm_object_print_static)
1834{
1835 /* XXX convert args. */
1836 vm_object_t object = (vm_object_t)addr;
1837 boolean_t full = have_addr;
1838
1839 vm_page_t p;
1840
1841 /* XXX count is an (unused) arg. Avoid shadowing it. */
1842#define count was_count
1843
1844 int count;
1845
1846 if (object == NULL)
1847 return;
1848
1849 db_iprintf(
1850 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n",
1851 object, (int)object->type, (u_long)object->size,
1852 object->resident_page_count, object->ref_count, object->flags);
1853 /*
1854 * XXX no %qd in kernel. Truncate object->backing_object_offset.
1855 */
1856 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n",
1857 object->shadow_count,
1858 object->backing_object ? object->backing_object->ref_count : 0,
1859 object->backing_object, (long)object->backing_object_offset);
1860
1861 if (!full)
1862 return;
1863
1864 db_indent += 2;
1865 count = 0;
1866 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = TAILQ_NEXT(p, listq)) {
1867 if (count == 0)
1868 db_iprintf("memory:=");
1869 else if (count == 6) {
1870 db_printf("\n");
1871 db_iprintf(" ...");
1872 count = 0;
1873 } else
1874 db_printf(",");
1875 count++;
1876
1877 db_printf("(off=0x%lx,page=0x%lx)",
1878 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p));
1879 }
1880 if (count != 0)
1881 db_printf("\n");
1882 db_indent -= 2;
1883}
1884
1885/* XXX. */
1886#undef count
1887
1888/* XXX need this non-static entry for calling from vm_map_print. */
1889void
1890vm_object_print(addr, have_addr, count, modif)
1891 /* db_expr_t */ long addr;
1892 boolean_t have_addr;
1893 /* db_expr_t */ long count;
1894 char *modif;
1895{
1896 vm_object_print_static(addr, have_addr, count, modif);
1897}
1898
1899DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
1900{
1901 vm_object_t object;
1902 int nl = 0;
1903 int c;
1904 for (object = TAILQ_FIRST(&vm_object_list);
1905 object != NULL;
1906 object = TAILQ_NEXT(object, object_list)) {
1907 vm_pindex_t idx, fidx;
1908 vm_pindex_t osize;
1909 vm_offset_t pa = -1, padiff;
1910 int rcount;
1911 vm_page_t m;
1912
1913 db_printf("new object: %p\n", (void *)object);
1914 if ( nl > 18) {
1915 c = cngetc();
1916 if (c != ' ')
1917 return;
1918 nl = 0;
1919 }
1920 nl++;
1921 rcount = 0;
1922 fidx = 0;
1923 osize = object->size;
1924 if (osize > 128)
1925 osize = 128;
1926 for(idx=0;idx<osize;idx++) {
1927 m = vm_page_lookup(object, idx);
1928 if (m == NULL) {
1929 if (rcount) {
1930 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1931 (long)fidx, rcount, (long)pa);
1932 if ( nl > 18) {
1933 c = cngetc();
1934 if (c != ' ')
1935 return;
1936 nl = 0;
1937 }
1938 nl++;
1939 rcount = 0;
1940 }
1941 continue;
1942 }
1943
1944
1945 if (rcount &&
1946 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
1947 ++rcount;
1948 continue;
1949 }
1950 if (rcount) {
1951 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
1952 padiff >>= PAGE_SHIFT;
1953 padiff &= PQ_L2_MASK;
1954 if (padiff == 0) {
1955 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
1956 ++rcount;
1957 continue;
1958 }
1959 db_printf(" index(%ld)run(%d)pa(0x%lx)",
1960 (long)fidx, rcount, (long)pa);
1961 db_printf("pd(%ld)\n", (long)padiff);
1962 if ( nl > 18) {
1963 c = cngetc();
1964 if (c != ' ')
1965 return;
1966 nl = 0;
1967 }
1968 nl++;
1969 }
1970 fidx = idx;
1971 pa = VM_PAGE_TO_PHYS(m);
1972 rcount = 1;
1973 }
1974 if (rcount) {
1975 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
1976 (long)fidx, rcount, (long)pa);
1977 if ( nl > 18) {
1978 c = cngetc();
1979 if (c != ' ')
1980 return;
1981 nl = 0;
1982 }
1983 nl++;
1984 }
1985 }
1986}
1987#endif /* DDB */