FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_object.c
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
65 /*
66 * Virtual memory object module.
67 */
68
69 #include <sys/cdefs.h>
70 __FBSDID("$FreeBSD: releng/5.2/sys/vm/vm_object.c 129737 2004-05-25 23:07:55Z des $");
71
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/lock.h>
75 #include <sys/mman.h>
76 #include <sys/mount.h>
77 #include <sys/kernel.h>
78 #include <sys/sysctl.h>
79 #include <sys/mutex.h>
80 #include <sys/proc.h> /* for curproc, pageproc */
81 #include <sys/socket.h>
82 #include <sys/vnode.h>
83 #include <sys/vmmeter.h>
84 #include <sys/sx.h>
85
86 #include <vm/vm.h>
87 #include <vm/vm_param.h>
88 #include <vm/pmap.h>
89 #include <vm/vm_map.h>
90 #include <vm/vm_object.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_pageout.h>
93 #include <vm/vm_pager.h>
94 #include <vm/swap_pager.h>
95 #include <vm/vm_kern.h>
96 #include <vm/vm_extern.h>
97 #include <vm/uma.h>
98
99 #define EASY_SCAN_FACTOR 8
100
101 #define MSYNC_FLUSH_HARDSEQ 0x01
102 #define MSYNC_FLUSH_SOFTSEQ 0x02
103
104 /*
105 * msync / VM object flushing optimizations
106 */
107 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ;
108 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags,
109 CTLFLAG_RW, &msync_flush_flags, 0, "");
110
111 static int old_msync;
112 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
113 "Use old (insecure) msync behavior");
114
115 static void vm_object_qcollapse(vm_object_t object);
116 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags);
117
118 /*
119 * Virtual memory objects maintain the actual data
120 * associated with allocated virtual memory. A given
121 * page of memory exists within exactly one object.
122 *
123 * An object is only deallocated when all "references"
124 * are given up. Only one "reference" to a given
125 * region of an object should be writeable.
126 *
127 * Associated with each object is a list of all resident
128 * memory pages belonging to that object; this list is
129 * maintained by the "vm_page" module, and locked by the object's
130 * lock.
131 *
132 * Each object also records a "pager" routine which is
133 * used to retrieve (and store) pages to the proper backing
134 * storage. In addition, objects may be backed by other
135 * objects from which they were virtual-copied.
136 *
137 * The only items within the object structure which are
138 * modified after time of creation are:
139 * reference count locked by object's lock
140 * pager routine locked by object's lock
141 *
142 */
143
144 struct object_q vm_object_list;
145 struct mtx vm_object_list_mtx; /* lock for object list and count */
146
147 struct vm_object kernel_object_store;
148 struct vm_object kmem_object_store;
149
150 static long object_collapses;
151 static long object_bypasses;
152 static int next_index;
153 static uma_zone_t obj_zone;
154 #define VM_OBJECTS_INIT 256
155
156 static void vm_object_zinit(void *mem, int size);
157
158 #ifdef INVARIANTS
159 static void vm_object_zdtor(void *mem, int size, void *arg);
160
161 static void
162 vm_object_zdtor(void *mem, int size, void *arg)
163 {
164 vm_object_t object;
165
166 object = (vm_object_t)mem;
167 KASSERT(TAILQ_EMPTY(&object->memq),
168 ("object %p has resident pages",
169 object));
170 KASSERT(object->paging_in_progress == 0,
171 ("object %p paging_in_progress = %d",
172 object, object->paging_in_progress));
173 KASSERT(object->resident_page_count == 0,
174 ("object %p resident_page_count = %d",
175 object, object->resident_page_count));
176 KASSERT(object->shadow_count == 0,
177 ("object %p shadow_count = %d",
178 object, object->shadow_count));
179 }
180 #endif
181
182 static void
183 vm_object_zinit(void *mem, int size)
184 {
185 vm_object_t object;
186
187 object = (vm_object_t)mem;
188 bzero(&object->mtx, sizeof(object->mtx));
189 VM_OBJECT_LOCK_INIT(object);
190
191 /* These are true for any object that has been freed */
192 object->paging_in_progress = 0;
193 object->resident_page_count = 0;
194 object->shadow_count = 0;
195 }
196
197 void
198 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object)
199 {
200 int incr;
201
202 TAILQ_INIT(&object->memq);
203 LIST_INIT(&object->shadow_head);
204
205 object->root = NULL;
206 object->type = type;
207 object->size = size;
208 object->generation = 1;
209 object->ref_count = 1;
210 object->flags = 0;
211 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
212 object->flags = OBJ_ONEMAPPING;
213 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
214 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
215 else
216 incr = size;
217 do
218 object->pg_color = next_index;
219 while (!atomic_cmpset_int(&next_index, object->pg_color,
220 (object->pg_color + incr) & PQ_L2_MASK));
221 object->handle = NULL;
222 object->backing_object = NULL;
223 object->backing_object_offset = (vm_ooffset_t) 0;
224
225 mtx_lock(&vm_object_list_mtx);
226 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
227 mtx_unlock(&vm_object_list_mtx);
228 }
229
230 /*
231 * vm_object_init:
232 *
233 * Initialize the VM objects module.
234 */
235 void
236 vm_object_init(void)
237 {
238 TAILQ_INIT(&vm_object_list);
239 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
240
241 VM_OBJECT_LOCK_INIT(&kernel_object_store);
242 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
243 kernel_object);
244
245 /*
246 * The kmem object's mutex is given a unique name, instead of
247 * "vm object", to avoid false reports of lock-order reversal
248 * with a system map mutex.
249 */
250 mtx_init(VM_OBJECT_MTX(kmem_object), "kmem object", NULL, MTX_DEF);
251 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
252 kmem_object);
253
254 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
255 #ifdef INVARIANTS
256 vm_object_zdtor,
257 #else
258 NULL,
259 #endif
260 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE);
261 uma_prealloc(obj_zone, VM_OBJECTS_INIT);
262 }
263
264 void
265 vm_object_clear_flag(vm_object_t object, u_short bits)
266 {
267
268 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
269 object->flags &= ~bits;
270 }
271
272 void
273 vm_object_pip_add(vm_object_t object, short i)
274 {
275
276 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
277 object->paging_in_progress += i;
278 }
279
280 void
281 vm_object_pip_subtract(vm_object_t object, short i)
282 {
283
284 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
285 object->paging_in_progress -= i;
286 }
287
288 void
289 vm_object_pip_wakeup(vm_object_t object)
290 {
291
292 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
293 object->paging_in_progress--;
294 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
295 vm_object_clear_flag(object, OBJ_PIPWNT);
296 wakeup(object);
297 }
298 }
299
300 void
301 vm_object_pip_wakeupn(vm_object_t object, short i)
302 {
303
304 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
305 if (i)
306 object->paging_in_progress -= i;
307 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
308 vm_object_clear_flag(object, OBJ_PIPWNT);
309 wakeup(object);
310 }
311 }
312
313 void
314 vm_object_pip_wait(vm_object_t object, char *waitid)
315 {
316
317 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
318 while (object->paging_in_progress) {
319 object->flags |= OBJ_PIPWNT;
320 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0);
321 }
322 }
323
324 /*
325 * vm_object_allocate_wait
326 *
327 * Return a new object with the given size, and give the user the
328 * option of waiting for it to complete or failing if the needed
329 * memory isn't available.
330 */
331 vm_object_t
332 vm_object_allocate_wait(objtype_t type, vm_pindex_t size, int flags)
333 {
334 vm_object_t result;
335
336 result = (vm_object_t) uma_zalloc(obj_zone, flags);
337
338 if (result != NULL)
339 _vm_object_allocate(type, size, result);
340
341 return (result);
342 }
343
344 /*
345 * vm_object_allocate:
346 *
347 * Returns a new object with the given size.
348 */
349 vm_object_t
350 vm_object_allocate(objtype_t type, vm_pindex_t size)
351 {
352 return(vm_object_allocate_wait(type, size, M_WAITOK));
353 }
354
355
356 /*
357 * vm_object_reference:
358 *
359 * Gets another reference to the given object. Note: OBJ_DEAD
360 * objects can be referenced during final cleaning.
361 */
362 void
363 vm_object_reference(vm_object_t object)
364 {
365 struct vnode *vp;
366 int flags;
367
368 if (object == NULL)
369 return;
370 VM_OBJECT_LOCK(object);
371 object->ref_count++;
372 if (object->type == OBJT_VNODE) {
373 vp = object->handle;
374 VI_LOCK(vp);
375 VM_OBJECT_UNLOCK(object);
376 for (flags = LK_INTERLOCK; vget(vp, flags, curthread);
377 flags = 0)
378 printf("vm_object_reference: delay in vget\n");
379 } else
380 VM_OBJECT_UNLOCK(object);
381 }
382
383 /*
384 * vm_object_reference_locked:
385 *
386 * Gets another reference to the given object.
387 *
388 * The object must be locked.
389 */
390 void
391 vm_object_reference_locked(vm_object_t object)
392 {
393 struct vnode *vp;
394
395 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
396 KASSERT((object->flags & OBJ_DEAD) == 0,
397 ("vm_object_reference_locked: dead object referenced"));
398 object->ref_count++;
399 if (object->type == OBJT_VNODE) {
400 vp = object->handle;
401 vref(vp);
402 }
403 }
404
405 /*
406 * Handle deallocating an object of type OBJT_VNODE.
407 */
408 void
409 vm_object_vndeallocate(vm_object_t object)
410 {
411 struct vnode *vp = (struct vnode *) object->handle;
412
413 GIANT_REQUIRED;
414 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
415 KASSERT(object->type == OBJT_VNODE,
416 ("vm_object_vndeallocate: not a vnode object"));
417 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
418 #ifdef INVARIANTS
419 if (object->ref_count == 0) {
420 vprint("vm_object_vndeallocate", vp);
421 panic("vm_object_vndeallocate: bad object reference count");
422 }
423 #endif
424
425 object->ref_count--;
426 if (object->ref_count == 0) {
427 mp_fixme("Unlocked vflag access.");
428 vp->v_vflag &= ~VV_TEXT;
429 }
430 VM_OBJECT_UNLOCK(object);
431 /*
432 * vrele may need a vop lock
433 */
434 vrele(vp);
435 }
436
437 /*
438 * vm_object_deallocate:
439 *
440 * Release a reference to the specified object,
441 * gained either through a vm_object_allocate
442 * or a vm_object_reference call. When all references
443 * are gone, storage associated with this object
444 * may be relinquished.
445 *
446 * No object may be locked.
447 */
448 void
449 vm_object_deallocate(vm_object_t object)
450 {
451 vm_object_t temp;
452
453 if (object != kmem_object)
454 mtx_lock(&Giant);
455 while (object != NULL) {
456 VM_OBJECT_LOCK(object);
457 if (object->type == OBJT_VNODE) {
458 vm_object_vndeallocate(object);
459 goto done;
460 }
461
462 KASSERT(object->ref_count != 0,
463 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
464
465 /*
466 * If the reference count goes to 0 we start calling
467 * vm_object_terminate() on the object chain.
468 * A ref count of 1 may be a special case depending on the
469 * shadow count being 0 or 1.
470 */
471 object->ref_count--;
472 if (object->ref_count > 1) {
473 VM_OBJECT_UNLOCK(object);
474 goto done;
475 } else if (object->ref_count == 1) {
476 if (object->shadow_count == 0) {
477 vm_object_set_flag(object, OBJ_ONEMAPPING);
478 } else if ((object->shadow_count == 1) &&
479 (object->handle == NULL) &&
480 (object->type == OBJT_DEFAULT ||
481 object->type == OBJT_SWAP)) {
482 vm_object_t robject;
483
484 robject = LIST_FIRST(&object->shadow_head);
485 KASSERT(robject != NULL,
486 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
487 object->ref_count,
488 object->shadow_count));
489 if (!VM_OBJECT_TRYLOCK(robject)) {
490 /*
491 * Avoid a potential deadlock.
492 */
493 object->ref_count++;
494 VM_OBJECT_UNLOCK(object);
495 continue;
496 }
497 if ((robject->handle == NULL) &&
498 (robject->type == OBJT_DEFAULT ||
499 robject->type == OBJT_SWAP)) {
500
501 robject->ref_count++;
502 retry:
503 if (robject->paging_in_progress) {
504 VM_OBJECT_UNLOCK(object);
505 vm_object_pip_wait(robject,
506 "objde1");
507 VM_OBJECT_LOCK(object);
508 goto retry;
509 } else if (object->paging_in_progress) {
510 VM_OBJECT_UNLOCK(robject);
511 object->flags |= OBJ_PIPWNT;
512 msleep(object,
513 VM_OBJECT_MTX(object),
514 PDROP | PVM, "objde2", 0);
515 VM_OBJECT_LOCK(robject);
516 VM_OBJECT_LOCK(object);
517 goto retry;
518 }
519 VM_OBJECT_UNLOCK(object);
520 if (robject->ref_count == 1) {
521 robject->ref_count--;
522 object = robject;
523 goto doterm;
524 }
525 object = robject;
526 vm_object_collapse(object);
527 VM_OBJECT_UNLOCK(object);
528 continue;
529 }
530 VM_OBJECT_UNLOCK(robject);
531 }
532 VM_OBJECT_UNLOCK(object);
533 goto done;
534 }
535 doterm:
536 temp = object->backing_object;
537 if (temp != NULL) {
538 VM_OBJECT_LOCK(temp);
539 LIST_REMOVE(object, shadow_list);
540 temp->shadow_count--;
541 temp->generation++;
542 VM_OBJECT_UNLOCK(temp);
543 object->backing_object = NULL;
544 }
545 /*
546 * Don't double-terminate, we could be in a termination
547 * recursion due to the terminate having to sync data
548 * to disk.
549 */
550 if ((object->flags & OBJ_DEAD) == 0)
551 vm_object_terminate(object);
552 else
553 VM_OBJECT_UNLOCK(object);
554 object = temp;
555 }
556 done:
557 if (object != kmem_object)
558 mtx_unlock(&Giant);
559 }
560
561 /*
562 * vm_object_terminate actually destroys the specified object, freeing
563 * up all previously used resources.
564 *
565 * The object must be locked.
566 * This routine may block.
567 */
568 void
569 vm_object_terminate(vm_object_t object)
570 {
571 vm_page_t p;
572 int s;
573
574 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
575
576 /*
577 * Make sure no one uses us.
578 */
579 vm_object_set_flag(object, OBJ_DEAD);
580
581 /*
582 * wait for the pageout daemon to be done with the object
583 */
584 vm_object_pip_wait(object, "objtrm");
585
586 KASSERT(!object->paging_in_progress,
587 ("vm_object_terminate: pageout in progress"));
588
589 /*
590 * Clean and free the pages, as appropriate. All references to the
591 * object are gone, so we don't need to lock it.
592 */
593 if (object->type == OBJT_VNODE) {
594 struct vnode *vp = (struct vnode *)object->handle;
595
596 /*
597 * Clean pages and flush buffers.
598 */
599 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
600 VM_OBJECT_UNLOCK(object);
601
602 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
603
604 VM_OBJECT_LOCK(object);
605 }
606
607 KASSERT(object->ref_count == 0,
608 ("vm_object_terminate: object with references, ref_count=%d",
609 object->ref_count));
610
611 /*
612 * Now free any remaining pages. For internal objects, this also
613 * removes them from paging queues. Don't free wired pages, just
614 * remove them from the object.
615 */
616 s = splvm();
617 vm_page_lock_queues();
618 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
619 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
620 ("vm_object_terminate: freeing busy page %p "
621 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
622 if (p->wire_count == 0) {
623 vm_page_busy(p);
624 vm_page_free(p);
625 cnt.v_pfree++;
626 } else {
627 vm_page_busy(p);
628 vm_page_remove(p);
629 }
630 }
631 vm_page_unlock_queues();
632 splx(s);
633
634 /*
635 * Let the pager know object is dead.
636 */
637 vm_pager_deallocate(object);
638 VM_OBJECT_UNLOCK(object);
639
640 /*
641 * Remove the object from the global object list.
642 */
643 mtx_lock(&vm_object_list_mtx);
644 TAILQ_REMOVE(&vm_object_list, object, object_list);
645 mtx_unlock(&vm_object_list_mtx);
646
647 wakeup(object);
648
649 /*
650 * Free the space for the object.
651 */
652 uma_zfree(obj_zone, object);
653 }
654
655 /*
656 * vm_object_page_clean
657 *
658 * Clean all dirty pages in the specified range of object. Leaves page
659 * on whatever queue it is currently on. If NOSYNC is set then do not
660 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
661 * leaving the object dirty.
662 *
663 * When stuffing pages asynchronously, allow clustering. XXX we need a
664 * synchronous clustering mode implementation.
665 *
666 * Odd semantics: if start == end, we clean everything.
667 *
668 * The object must be locked.
669 */
670 void
671 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
672 {
673 vm_page_t p, np;
674 vm_pindex_t tstart, tend;
675 vm_pindex_t pi;
676 int clearobjflags;
677 int pagerflags;
678 int curgeneration;
679
680 GIANT_REQUIRED;
681 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
682 if (object->type != OBJT_VNODE ||
683 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
684 return;
685
686 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
687 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
688
689 vm_object_set_flag(object, OBJ_CLEANING);
690
691 tstart = start;
692 if (end == 0) {
693 tend = object->size;
694 } else {
695 tend = end;
696 }
697
698 vm_page_lock_queues();
699 /*
700 * If the caller is smart and only msync()s a range he knows is
701 * dirty, we may be able to avoid an object scan. This results in
702 * a phenominal improvement in performance. We cannot do this
703 * as a matter of course because the object may be huge - e.g.
704 * the size might be in the gigabytes or terrabytes.
705 */
706 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
707 vm_pindex_t tscan;
708 int scanlimit;
709 int scanreset;
710
711 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
712 if (scanreset < 16)
713 scanreset = 16;
714 pagerflags |= VM_PAGER_IGNORE_CLEANCHK;
715
716 scanlimit = scanreset;
717 tscan = tstart;
718 while (tscan < tend) {
719 curgeneration = object->generation;
720 p = vm_page_lookup(object, tscan);
721 if (p == NULL || p->valid == 0 ||
722 (p->queue - p->pc) == PQ_CACHE) {
723 if (--scanlimit == 0)
724 break;
725 ++tscan;
726 continue;
727 }
728 vm_page_test_dirty(p);
729 if ((p->dirty & p->valid) == 0) {
730 if (--scanlimit == 0)
731 break;
732 ++tscan;
733 continue;
734 }
735 /*
736 * If we have been asked to skip nosync pages and
737 * this is a nosync page, we can't continue.
738 */
739 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
740 if (--scanlimit == 0)
741 break;
742 ++tscan;
743 continue;
744 }
745 scanlimit = scanreset;
746
747 /*
748 * This returns 0 if it was unable to busy the first
749 * page (i.e. had to sleep).
750 */
751 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
752 }
753
754 /*
755 * If everything was dirty and we flushed it successfully,
756 * and the requested range is not the entire object, we
757 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
758 * return immediately.
759 */
760 if (tscan >= tend && (tstart || tend < object->size)) {
761 vm_page_unlock_queues();
762 vm_object_clear_flag(object, OBJ_CLEANING);
763 return;
764 }
765 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK;
766 }
767
768 /*
769 * Generally set CLEANCHK interlock and make the page read-only so
770 * we can then clear the object flags.
771 *
772 * However, if this is a nosync mmap then the object is likely to
773 * stay dirty so do not mess with the page and do not clear the
774 * object flags.
775 */
776 clearobjflags = 1;
777 TAILQ_FOREACH(p, &object->memq, listq) {
778 vm_page_flag_set(p, PG_CLEANCHK);
779 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
780 clearobjflags = 0;
781 else
782 pmap_page_protect(p, VM_PROT_READ);
783 }
784
785 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
786 struct vnode *vp;
787
788 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
789 if (object->type == OBJT_VNODE &&
790 (vp = (struct vnode *)object->handle) != NULL) {
791 VI_LOCK(vp);
792 if (vp->v_iflag & VI_OBJDIRTY)
793 vp->v_iflag &= ~VI_OBJDIRTY;
794 VI_UNLOCK(vp);
795 }
796 }
797
798 rescan:
799 curgeneration = object->generation;
800
801 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
802 int n;
803
804 np = TAILQ_NEXT(p, listq);
805
806 again:
807 pi = p->pindex;
808 if (((p->flags & PG_CLEANCHK) == 0) ||
809 (pi < tstart) || (pi >= tend) ||
810 (p->valid == 0) ||
811 ((p->queue - p->pc) == PQ_CACHE)) {
812 vm_page_flag_clear(p, PG_CLEANCHK);
813 continue;
814 }
815
816 vm_page_test_dirty(p);
817 if ((p->dirty & p->valid) == 0) {
818 vm_page_flag_clear(p, PG_CLEANCHK);
819 continue;
820 }
821
822 /*
823 * If we have been asked to skip nosync pages and this is a
824 * nosync page, skip it. Note that the object flags were
825 * not cleared in this case so we do not have to set them.
826 */
827 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
828 vm_page_flag_clear(p, PG_CLEANCHK);
829 continue;
830 }
831
832 n = vm_object_page_collect_flush(object, p,
833 curgeneration, pagerflags);
834 if (n == 0)
835 goto rescan;
836
837 if (object->generation != curgeneration)
838 goto rescan;
839
840 /*
841 * Try to optimize the next page. If we can't we pick up
842 * our (random) scan where we left off.
843 */
844 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
845 if ((p = vm_page_lookup(object, pi + n)) != NULL)
846 goto again;
847 }
848 }
849 vm_page_unlock_queues();
850 #if 0
851 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
852 #endif
853
854 vm_object_clear_flag(object, OBJ_CLEANING);
855 return;
856 }
857
858 static int
859 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
860 {
861 int runlen;
862 int s;
863 int maxf;
864 int chkb;
865 int maxb;
866 int i;
867 vm_pindex_t pi;
868 vm_page_t maf[vm_pageout_page_count];
869 vm_page_t mab[vm_pageout_page_count];
870 vm_page_t ma[vm_pageout_page_count];
871
872 s = splvm();
873 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
874 pi = p->pindex;
875 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) {
876 vm_page_lock_queues();
877 if (object->generation != curgeneration) {
878 splx(s);
879 return(0);
880 }
881 }
882 maxf = 0;
883 for(i = 1; i < vm_pageout_page_count; i++) {
884 vm_page_t tp;
885
886 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
887 if ((tp->flags & PG_BUSY) ||
888 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
889 (tp->flags & PG_CLEANCHK) == 0) ||
890 (tp->busy != 0))
891 break;
892 if((tp->queue - tp->pc) == PQ_CACHE) {
893 vm_page_flag_clear(tp, PG_CLEANCHK);
894 break;
895 }
896 vm_page_test_dirty(tp);
897 if ((tp->dirty & tp->valid) == 0) {
898 vm_page_flag_clear(tp, PG_CLEANCHK);
899 break;
900 }
901 maf[ i - 1 ] = tp;
902 maxf++;
903 continue;
904 }
905 break;
906 }
907
908 maxb = 0;
909 chkb = vm_pageout_page_count - maxf;
910 if (chkb) {
911 for(i = 1; i < chkb;i++) {
912 vm_page_t tp;
913
914 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
915 if ((tp->flags & PG_BUSY) ||
916 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
917 (tp->flags & PG_CLEANCHK) == 0) ||
918 (tp->busy != 0))
919 break;
920 if ((tp->queue - tp->pc) == PQ_CACHE) {
921 vm_page_flag_clear(tp, PG_CLEANCHK);
922 break;
923 }
924 vm_page_test_dirty(tp);
925 if ((tp->dirty & tp->valid) == 0) {
926 vm_page_flag_clear(tp, PG_CLEANCHK);
927 break;
928 }
929 mab[ i - 1 ] = tp;
930 maxb++;
931 continue;
932 }
933 break;
934 }
935 }
936
937 for(i = 0; i < maxb; i++) {
938 int index = (maxb - i) - 1;
939 ma[index] = mab[i];
940 vm_page_flag_clear(ma[index], PG_CLEANCHK);
941 }
942 vm_page_flag_clear(p, PG_CLEANCHK);
943 ma[maxb] = p;
944 for(i = 0; i < maxf; i++) {
945 int index = (maxb + i) + 1;
946 ma[index] = maf[i];
947 vm_page_flag_clear(ma[index], PG_CLEANCHK);
948 }
949 runlen = maxb + maxf + 1;
950
951 splx(s);
952 vm_pageout_flush(ma, runlen, pagerflags);
953 for (i = 0; i < runlen; i++) {
954 if (ma[i]->valid & ma[i]->dirty) {
955 pmap_page_protect(ma[i], VM_PROT_READ);
956 vm_page_flag_set(ma[i], PG_CLEANCHK);
957
958 /*
959 * maxf will end up being the actual number of pages
960 * we wrote out contiguously, non-inclusive of the
961 * first page. We do not count look-behind pages.
962 */
963 if (i >= maxb + 1 && (maxf > i - maxb - 1))
964 maxf = i - maxb - 1;
965 }
966 }
967 return(maxf + 1);
968 }
969
970 /*
971 * Note that there is absolutely no sense in writing out
972 * anonymous objects, so we track down the vnode object
973 * to write out.
974 * We invalidate (remove) all pages from the address space
975 * for semantic correctness.
976 *
977 * Note: certain anonymous maps, such as MAP_NOSYNC maps,
978 * may start out with a NULL object.
979 */
980 void
981 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
982 boolean_t syncio, boolean_t invalidate)
983 {
984 vm_object_t backing_object;
985 struct vnode *vp;
986 int flags;
987
988 if (object == NULL)
989 return;
990 VM_OBJECT_LOCK(object);
991 while ((backing_object = object->backing_object) != NULL) {
992 VM_OBJECT_LOCK(backing_object);
993 VM_OBJECT_UNLOCK(object);
994 object = backing_object;
995 offset += object->backing_object_offset;
996 if (object->size < OFF_TO_IDX(offset + size))
997 size = IDX_TO_OFF(object->size) - offset;
998 }
999 /*
1000 * Flush pages if writing is allowed, invalidate them
1001 * if invalidation requested. Pages undergoing I/O
1002 * will be ignored by vm_object_page_remove().
1003 *
1004 * We cannot lock the vnode and then wait for paging
1005 * to complete without deadlocking against vm_fault.
1006 * Instead we simply call vm_object_page_remove() and
1007 * allow it to block internally on a page-by-page
1008 * basis when it encounters pages undergoing async
1009 * I/O.
1010 */
1011 if (object->type == OBJT_VNODE &&
1012 (object->flags & OBJ_MIGHTBEDIRTY) != 0) {
1013 vp = object->handle;
1014 VM_OBJECT_UNLOCK(object);
1015 mtx_lock(&Giant);
1016 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
1017 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
1018 flags |= invalidate ? OBJPC_INVAL : 0;
1019 VM_OBJECT_LOCK(object);
1020 vm_object_page_clean(object,
1021 OFF_TO_IDX(offset),
1022 OFF_TO_IDX(offset + size + PAGE_MASK),
1023 flags);
1024 VM_OBJECT_UNLOCK(object);
1025 VOP_UNLOCK(vp, 0, curthread);
1026 mtx_unlock(&Giant);
1027 VM_OBJECT_LOCK(object);
1028 }
1029 if ((object->type == OBJT_VNODE ||
1030 object->type == OBJT_DEVICE) && invalidate) {
1031 vm_object_page_remove(object,
1032 OFF_TO_IDX(offset),
1033 OFF_TO_IDX(offset + size + PAGE_MASK),
1034 old_msync ? FALSE : TRUE);
1035 }
1036 VM_OBJECT_UNLOCK(object);
1037 }
1038
1039 /*
1040 * vm_object_madvise:
1041 *
1042 * Implements the madvise function at the object/page level.
1043 *
1044 * MADV_WILLNEED (any object)
1045 *
1046 * Activate the specified pages if they are resident.
1047 *
1048 * MADV_DONTNEED (any object)
1049 *
1050 * Deactivate the specified pages if they are resident.
1051 *
1052 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
1053 * OBJ_ONEMAPPING only)
1054 *
1055 * Deactivate and clean the specified pages if they are
1056 * resident. This permits the process to reuse the pages
1057 * without faulting or the kernel to reclaim the pages
1058 * without I/O.
1059 */
1060 void
1061 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
1062 {
1063 vm_pindex_t end, tpindex;
1064 vm_object_t backing_object, tobject;
1065 vm_page_t m;
1066
1067 if (object == NULL)
1068 return;
1069 end = pindex + count;
1070 /*
1071 * Locate and adjust resident pages
1072 */
1073 for (; pindex < end; pindex += 1) {
1074 relookup:
1075 tobject = object;
1076 tpindex = pindex;
1077 VM_OBJECT_LOCK(tobject);
1078 shadowlookup:
1079 /*
1080 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1081 * and those pages must be OBJ_ONEMAPPING.
1082 */
1083 if (advise == MADV_FREE) {
1084 if ((tobject->type != OBJT_DEFAULT &&
1085 tobject->type != OBJT_SWAP) ||
1086 (tobject->flags & OBJ_ONEMAPPING) == 0) {
1087 goto unlock_tobject;
1088 }
1089 }
1090 m = vm_page_lookup(tobject, tpindex);
1091 if (m == NULL) {
1092 /*
1093 * There may be swap even if there is no backing page
1094 */
1095 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1096 swap_pager_freespace(tobject, tpindex, 1);
1097 /*
1098 * next object
1099 */
1100 backing_object = tobject->backing_object;
1101 if (backing_object == NULL)
1102 goto unlock_tobject;
1103 VM_OBJECT_LOCK(backing_object);
1104 VM_OBJECT_UNLOCK(tobject);
1105 tobject = backing_object;
1106 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1107 goto shadowlookup;
1108 }
1109 /*
1110 * If the page is busy or not in a normal active state,
1111 * we skip it. If the page is not managed there are no
1112 * page queues to mess with. Things can break if we mess
1113 * with pages in any of the below states.
1114 */
1115 vm_page_lock_queues();
1116 if (m->hold_count ||
1117 m->wire_count ||
1118 (m->flags & PG_UNMANAGED) ||
1119 m->valid != VM_PAGE_BITS_ALL) {
1120 vm_page_unlock_queues();
1121 goto unlock_tobject;
1122 }
1123 if (vm_page_sleep_if_busy(m, TRUE, "madvpo")) {
1124 VM_OBJECT_UNLOCK(tobject);
1125 goto relookup;
1126 }
1127 if (advise == MADV_WILLNEED) {
1128 vm_page_activate(m);
1129 } else if (advise == MADV_DONTNEED) {
1130 vm_page_dontneed(m);
1131 } else if (advise == MADV_FREE) {
1132 /*
1133 * Mark the page clean. This will allow the page
1134 * to be freed up by the system. However, such pages
1135 * are often reused quickly by malloc()/free()
1136 * so we do not do anything that would cause
1137 * a page fault if we can help it.
1138 *
1139 * Specifically, we do not try to actually free
1140 * the page now nor do we try to put it in the
1141 * cache (which would cause a page fault on reuse).
1142 *
1143 * But we do make the page is freeable as we
1144 * can without actually taking the step of unmapping
1145 * it.
1146 */
1147 pmap_clear_modify(m);
1148 m->dirty = 0;
1149 m->act_count = 0;
1150 vm_page_dontneed(m);
1151 }
1152 vm_page_unlock_queues();
1153 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1154 swap_pager_freespace(tobject, tpindex, 1);
1155 unlock_tobject:
1156 VM_OBJECT_UNLOCK(tobject);
1157 }
1158 }
1159
1160 /*
1161 * vm_object_shadow:
1162 *
1163 * Create a new object which is backed by the
1164 * specified existing object range. The source
1165 * object reference is deallocated.
1166 *
1167 * The new object and offset into that object
1168 * are returned in the source parameters.
1169 */
1170 void
1171 vm_object_shadow(
1172 vm_object_t *object, /* IN/OUT */
1173 vm_ooffset_t *offset, /* IN/OUT */
1174 vm_size_t length)
1175 {
1176 vm_object_t source;
1177 vm_object_t result;
1178
1179 source = *object;
1180
1181 /*
1182 * Don't create the new object if the old object isn't shared.
1183 */
1184 if (source != NULL) {
1185 VM_OBJECT_LOCK(source);
1186 if (source->ref_count == 1 &&
1187 source->handle == NULL &&
1188 (source->type == OBJT_DEFAULT ||
1189 source->type == OBJT_SWAP)) {
1190 VM_OBJECT_UNLOCK(source);
1191 return;
1192 }
1193 VM_OBJECT_UNLOCK(source);
1194 }
1195
1196 /*
1197 * Allocate a new object with the given length.
1198 */
1199 result = vm_object_allocate(OBJT_DEFAULT, length);
1200
1201 /*
1202 * The new object shadows the source object, adding a reference to it.
1203 * Our caller changes his reference to point to the new object,
1204 * removing a reference to the source object. Net result: no change
1205 * of reference count.
1206 *
1207 * Try to optimize the result object's page color when shadowing
1208 * in order to maintain page coloring consistency in the combined
1209 * shadowed object.
1210 */
1211 result->backing_object = source;
1212 if (source != NULL) {
1213 VM_OBJECT_LOCK(source);
1214 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
1215 source->shadow_count++;
1216 source->generation++;
1217 if (length < source->size)
1218 length = source->size;
1219 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 ||
1220 source->generation > 1)
1221 length = PQ_L2_SIZE / 3 + PQ_PRIME1;
1222 result->pg_color = (source->pg_color +
1223 length * source->generation) & PQ_L2_MASK;
1224 VM_OBJECT_UNLOCK(source);
1225 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) &
1226 PQ_L2_MASK;
1227 }
1228
1229 /*
1230 * Store the offset into the source object, and fix up the offset into
1231 * the new object.
1232 */
1233 result->backing_object_offset = *offset;
1234
1235 /*
1236 * Return the new things
1237 */
1238 *offset = 0;
1239 *object = result;
1240 }
1241
1242 /*
1243 * vm_object_split:
1244 *
1245 * Split the pages in a map entry into a new object. This affords
1246 * easier removal of unused pages, and keeps object inheritance from
1247 * being a negative impact on memory usage.
1248 */
1249 void
1250 vm_object_split(vm_map_entry_t entry)
1251 {
1252 vm_page_t m;
1253 vm_object_t orig_object, new_object, source;
1254 vm_offset_t s, e;
1255 vm_pindex_t offidxstart, offidxend;
1256 vm_size_t idx, size;
1257 vm_ooffset_t offset;
1258
1259 GIANT_REQUIRED;
1260
1261 orig_object = entry->object.vm_object;
1262 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
1263 return;
1264 if (orig_object->ref_count <= 1)
1265 return;
1266
1267 offset = entry->offset;
1268 s = entry->start;
1269 e = entry->end;
1270
1271 offidxstart = OFF_TO_IDX(offset);
1272 offidxend = offidxstart + OFF_TO_IDX(e - s);
1273 size = offidxend - offidxstart;
1274
1275 new_object = vm_pager_allocate(orig_object->type,
1276 NULL, IDX_TO_OFF(size), VM_PROT_ALL, 0LL);
1277 if (new_object == NULL)
1278 return;
1279
1280 VM_OBJECT_LOCK(new_object);
1281 VM_OBJECT_LOCK(orig_object);
1282 source = orig_object->backing_object;
1283 if (source != NULL) {
1284 VM_OBJECT_LOCK(source);
1285 LIST_INSERT_HEAD(&source->shadow_head,
1286 new_object, shadow_list);
1287 source->shadow_count++;
1288 source->generation++;
1289 vm_object_reference_locked(source); /* for new_object */
1290 vm_object_clear_flag(source, OBJ_ONEMAPPING);
1291 VM_OBJECT_UNLOCK(source);
1292 new_object->backing_object_offset =
1293 orig_object->backing_object_offset + offset;
1294 new_object->backing_object = source;
1295 }
1296 for (idx = 0; idx < size; idx++) {
1297 retry:
1298 m = vm_page_lookup(orig_object, offidxstart + idx);
1299 if (m == NULL)
1300 continue;
1301
1302 /*
1303 * We must wait for pending I/O to complete before we can
1304 * rename the page.
1305 *
1306 * We do not have to VM_PROT_NONE the page as mappings should
1307 * not be changed by this operation.
1308 */
1309 vm_page_lock_queues();
1310 if ((m->flags & PG_BUSY) || m->busy) {
1311 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
1312 VM_OBJECT_UNLOCK(orig_object);
1313 VM_OBJECT_UNLOCK(new_object);
1314 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0);
1315 VM_OBJECT_LOCK(new_object);
1316 VM_OBJECT_LOCK(orig_object);
1317 goto retry;
1318 }
1319 vm_page_busy(m);
1320 vm_page_rename(m, new_object, idx);
1321 /* page automatically made dirty by rename and cache handled */
1322 vm_page_busy(m);
1323 vm_page_unlock_queues();
1324 }
1325 if (orig_object->type == OBJT_SWAP) {
1326 /*
1327 * swap_pager_copy() can sleep, in which case the orig_object's
1328 * and new_object's locks are released and reacquired.
1329 */
1330 swap_pager_copy(orig_object, new_object, offidxstart, 0);
1331 }
1332 VM_OBJECT_UNLOCK(orig_object);
1333 vm_page_lock_queues();
1334 TAILQ_FOREACH(m, &new_object->memq, listq)
1335 vm_page_wakeup(m);
1336 vm_page_unlock_queues();
1337 VM_OBJECT_UNLOCK(new_object);
1338 entry->object.vm_object = new_object;
1339 entry->offset = 0LL;
1340 vm_object_deallocate(orig_object);
1341 }
1342
1343 #define OBSC_TEST_ALL_SHADOWED 0x0001
1344 #define OBSC_COLLAPSE_NOWAIT 0x0002
1345 #define OBSC_COLLAPSE_WAIT 0x0004
1346
1347 static int
1348 vm_object_backing_scan(vm_object_t object, int op)
1349 {
1350 int s;
1351 int r = 1;
1352 vm_page_t p;
1353 vm_object_t backing_object;
1354 vm_pindex_t backing_offset_index;
1355
1356 s = splvm();
1357 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1358 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED);
1359
1360 backing_object = object->backing_object;
1361 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1362
1363 /*
1364 * Initial conditions
1365 */
1366 if (op & OBSC_TEST_ALL_SHADOWED) {
1367 /*
1368 * We do not want to have to test for the existence of
1369 * swap pages in the backing object. XXX but with the
1370 * new swapper this would be pretty easy to do.
1371 *
1372 * XXX what about anonymous MAP_SHARED memory that hasn't
1373 * been ZFOD faulted yet? If we do not test for this, the
1374 * shadow test may succeed! XXX
1375 */
1376 if (backing_object->type != OBJT_DEFAULT) {
1377 splx(s);
1378 return (0);
1379 }
1380 }
1381 if (op & OBSC_COLLAPSE_WAIT) {
1382 vm_object_set_flag(backing_object, OBJ_DEAD);
1383 }
1384
1385 /*
1386 * Our scan
1387 */
1388 p = TAILQ_FIRST(&backing_object->memq);
1389 while (p) {
1390 vm_page_t next = TAILQ_NEXT(p, listq);
1391 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1392
1393 if (op & OBSC_TEST_ALL_SHADOWED) {
1394 vm_page_t pp;
1395
1396 /*
1397 * Ignore pages outside the parent object's range
1398 * and outside the parent object's mapping of the
1399 * backing object.
1400 *
1401 * note that we do not busy the backing object's
1402 * page.
1403 */
1404 if (
1405 p->pindex < backing_offset_index ||
1406 new_pindex >= object->size
1407 ) {
1408 p = next;
1409 continue;
1410 }
1411
1412 /*
1413 * See if the parent has the page or if the parent's
1414 * object pager has the page. If the parent has the
1415 * page but the page is not valid, the parent's
1416 * object pager must have the page.
1417 *
1418 * If this fails, the parent does not completely shadow
1419 * the object and we might as well give up now.
1420 */
1421
1422 pp = vm_page_lookup(object, new_pindex);
1423 if (
1424 (pp == NULL || pp->valid == 0) &&
1425 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1426 ) {
1427 r = 0;
1428 break;
1429 }
1430 }
1431
1432 /*
1433 * Check for busy page
1434 */
1435 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1436 vm_page_t pp;
1437
1438 vm_page_lock_queues();
1439 if (op & OBSC_COLLAPSE_NOWAIT) {
1440 if ((p->flags & PG_BUSY) ||
1441 !p->valid ||
1442 p->hold_count ||
1443 p->wire_count ||
1444 p->busy) {
1445 vm_page_unlock_queues();
1446 p = next;
1447 continue;
1448 }
1449 } else if (op & OBSC_COLLAPSE_WAIT) {
1450 if ((p->flags & PG_BUSY) || p->busy) {
1451 vm_page_flag_set(p,
1452 PG_WANTED | PG_REFERENCED);
1453 VM_OBJECT_UNLOCK(backing_object);
1454 VM_OBJECT_UNLOCK(object);
1455 msleep(p, &vm_page_queue_mtx,
1456 PDROP | PVM, "vmocol", 0);
1457 VM_OBJECT_LOCK(object);
1458 VM_OBJECT_LOCK(backing_object);
1459 /*
1460 * If we slept, anything could have
1461 * happened. Since the object is
1462 * marked dead, the backing offset
1463 * should not have changed so we
1464 * just restart our scan.
1465 */
1466 p = TAILQ_FIRST(&backing_object->memq);
1467 continue;
1468 }
1469 }
1470
1471 /*
1472 * Busy the page
1473 */
1474 vm_page_busy(p);
1475 vm_page_unlock_queues();
1476
1477 KASSERT(
1478 p->object == backing_object,
1479 ("vm_object_qcollapse(): object mismatch")
1480 );
1481
1482 /*
1483 * Destroy any associated swap
1484 */
1485 if (backing_object->type == OBJT_SWAP) {
1486 swap_pager_freespace(
1487 backing_object,
1488 p->pindex,
1489 1
1490 );
1491 }
1492
1493 if (
1494 p->pindex < backing_offset_index ||
1495 new_pindex >= object->size
1496 ) {
1497 /*
1498 * Page is out of the parent object's range, we
1499 * can simply destroy it.
1500 */
1501 vm_page_lock_queues();
1502 pmap_remove_all(p);
1503 vm_page_free(p);
1504 vm_page_unlock_queues();
1505 p = next;
1506 continue;
1507 }
1508
1509 pp = vm_page_lookup(object, new_pindex);
1510 if (
1511 pp != NULL ||
1512 vm_pager_has_page(object, new_pindex, NULL, NULL)
1513 ) {
1514 /*
1515 * page already exists in parent OR swap exists
1516 * for this location in the parent. Destroy
1517 * the original page from the backing object.
1518 *
1519 * Leave the parent's page alone
1520 */
1521 vm_page_lock_queues();
1522 pmap_remove_all(p);
1523 vm_page_free(p);
1524 vm_page_unlock_queues();
1525 p = next;
1526 continue;
1527 }
1528
1529 /*
1530 * Page does not exist in parent, rename the
1531 * page from the backing object to the main object.
1532 *
1533 * If the page was mapped to a process, it can remain
1534 * mapped through the rename.
1535 */
1536 vm_page_lock_queues();
1537 vm_page_rename(p, object, new_pindex);
1538 vm_page_unlock_queues();
1539 /* page automatically made dirty by rename */
1540 }
1541 p = next;
1542 }
1543 splx(s);
1544 return (r);
1545 }
1546
1547
1548 /*
1549 * this version of collapse allows the operation to occur earlier and
1550 * when paging_in_progress is true for an object... This is not a complete
1551 * operation, but should plug 99.9% of the rest of the leaks.
1552 */
1553 static void
1554 vm_object_qcollapse(vm_object_t object)
1555 {
1556 vm_object_t backing_object = object->backing_object;
1557
1558 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1559 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED);
1560
1561 if (backing_object->ref_count != 1)
1562 return;
1563
1564 backing_object->ref_count += 2;
1565
1566 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1567
1568 backing_object->ref_count -= 2;
1569 }
1570
1571 /*
1572 * vm_object_collapse:
1573 *
1574 * Collapse an object with the object backing it.
1575 * Pages in the backing object are moved into the
1576 * parent, and the backing object is deallocated.
1577 */
1578 void
1579 vm_object_collapse(vm_object_t object)
1580 {
1581 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1582
1583 while (TRUE) {
1584 vm_object_t backing_object;
1585
1586 /*
1587 * Verify that the conditions are right for collapse:
1588 *
1589 * The object exists and the backing object exists.
1590 */
1591 if ((backing_object = object->backing_object) == NULL)
1592 break;
1593
1594 /*
1595 * we check the backing object first, because it is most likely
1596 * not collapsable.
1597 */
1598 VM_OBJECT_LOCK(backing_object);
1599 if (backing_object->handle != NULL ||
1600 (backing_object->type != OBJT_DEFAULT &&
1601 backing_object->type != OBJT_SWAP) ||
1602 (backing_object->flags & OBJ_DEAD) ||
1603 object->handle != NULL ||
1604 (object->type != OBJT_DEFAULT &&
1605 object->type != OBJT_SWAP) ||
1606 (object->flags & OBJ_DEAD)) {
1607 VM_OBJECT_UNLOCK(backing_object);
1608 break;
1609 }
1610
1611 if (
1612 object->paging_in_progress != 0 ||
1613 backing_object->paging_in_progress != 0
1614 ) {
1615 vm_object_qcollapse(object);
1616 VM_OBJECT_UNLOCK(backing_object);
1617 break;
1618 }
1619 /*
1620 * We know that we can either collapse the backing object (if
1621 * the parent is the only reference to it) or (perhaps) have
1622 * the parent bypass the object if the parent happens to shadow
1623 * all the resident pages in the entire backing object.
1624 *
1625 * This is ignoring pager-backed pages such as swap pages.
1626 * vm_object_backing_scan fails the shadowing test in this
1627 * case.
1628 */
1629 if (backing_object->ref_count == 1) {
1630 /*
1631 * If there is exactly one reference to the backing
1632 * object, we can collapse it into the parent.
1633 */
1634 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1635
1636 /*
1637 * Move the pager from backing_object to object.
1638 */
1639 if (backing_object->type == OBJT_SWAP) {
1640 /*
1641 * swap_pager_copy() can sleep, in which case
1642 * the backing_object's and object's locks are
1643 * released and reacquired.
1644 */
1645 swap_pager_copy(
1646 backing_object,
1647 object,
1648 OFF_TO_IDX(object->backing_object_offset), TRUE);
1649 }
1650 /*
1651 * Object now shadows whatever backing_object did.
1652 * Note that the reference to
1653 * backing_object->backing_object moves from within
1654 * backing_object to within object.
1655 */
1656 LIST_REMOVE(object, shadow_list);
1657 backing_object->shadow_count--;
1658 backing_object->generation++;
1659 if (backing_object->backing_object) {
1660 VM_OBJECT_LOCK(backing_object->backing_object);
1661 LIST_REMOVE(backing_object, shadow_list);
1662 LIST_INSERT_HEAD(
1663 &backing_object->backing_object->shadow_head,
1664 object, shadow_list);
1665 /*
1666 * The shadow_count has not changed.
1667 */
1668 backing_object->backing_object->generation++;
1669 VM_OBJECT_UNLOCK(backing_object->backing_object);
1670 }
1671 object->backing_object = backing_object->backing_object;
1672 object->backing_object_offset +=
1673 backing_object->backing_object_offset;
1674 /* XXX */ VM_OBJECT_UNLOCK(object);
1675
1676 /*
1677 * Discard backing_object.
1678 *
1679 * Since the backing object has no pages, no pager left,
1680 * and no object references within it, all that is
1681 * necessary is to dispose of it.
1682 */
1683 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1684 VM_OBJECT_UNLOCK(backing_object);
1685
1686 mtx_lock(&vm_object_list_mtx);
1687 TAILQ_REMOVE(
1688 &vm_object_list,
1689 backing_object,
1690 object_list
1691 );
1692 mtx_unlock(&vm_object_list_mtx);
1693
1694 /* XXX */ VM_OBJECT_LOCK(object);
1695 uma_zfree(obj_zone, backing_object);
1696
1697 object_collapses++;
1698 } else {
1699 vm_object_t new_backing_object;
1700
1701 /*
1702 * If we do not entirely shadow the backing object,
1703 * there is nothing we can do so we give up.
1704 */
1705 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1706 VM_OBJECT_UNLOCK(backing_object);
1707 break;
1708 }
1709
1710 /*
1711 * Make the parent shadow the next object in the
1712 * chain. Deallocating backing_object will not remove
1713 * it, since its reference count is at least 2.
1714 */
1715 LIST_REMOVE(object, shadow_list);
1716 backing_object->shadow_count--;
1717 backing_object->generation++;
1718
1719 new_backing_object = backing_object->backing_object;
1720 if ((object->backing_object = new_backing_object) != NULL) {
1721 VM_OBJECT_LOCK(new_backing_object);
1722 LIST_INSERT_HEAD(
1723 &new_backing_object->shadow_head,
1724 object,
1725 shadow_list
1726 );
1727 new_backing_object->shadow_count++;
1728 new_backing_object->generation++;
1729 vm_object_reference_locked(new_backing_object);
1730 VM_OBJECT_UNLOCK(new_backing_object);
1731 object->backing_object_offset +=
1732 backing_object->backing_object_offset;
1733 }
1734
1735 /*
1736 * Drop the reference count on backing_object. Since
1737 * its ref_count was at least 2, it will not vanish.
1738 */
1739 backing_object->ref_count--;
1740 VM_OBJECT_UNLOCK(backing_object);
1741 object_bypasses++;
1742 }
1743
1744 /*
1745 * Try again with this object's new backing object.
1746 */
1747 }
1748 }
1749
1750 /*
1751 * vm_object_page_remove:
1752 *
1753 * Removes all physical pages in the given range from the
1754 * object's list of pages. If the range's end is zero, all
1755 * physical pages from the range's start to the end of the object
1756 * are deleted.
1757 *
1758 * The object must be locked.
1759 */
1760 void
1761 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
1762 boolean_t clean_only)
1763 {
1764 vm_page_t p, next;
1765
1766 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1767 if (object->resident_page_count == 0)
1768 return;
1769
1770 /*
1771 * Since physically-backed objects do not use managed pages, we can't
1772 * remove pages from the object (we must instead remove the page
1773 * references, and then destroy the object).
1774 */
1775 KASSERT(object->type != OBJT_PHYS,
1776 ("attempt to remove pages from a physical object"));
1777
1778 vm_object_pip_add(object, 1);
1779 again:
1780 vm_page_lock_queues();
1781 if ((p = TAILQ_FIRST(&object->memq)) != NULL) {
1782 if (p->pindex < start) {
1783 p = vm_page_splay(start, object->root);
1784 if ((object->root = p)->pindex < start)
1785 p = TAILQ_NEXT(p, listq);
1786 }
1787 }
1788 /*
1789 * Assert: the variable p is either (1) the page with the
1790 * least pindex greater than or equal to the parameter pindex
1791 * or (2) NULL.
1792 */
1793 for (;
1794 p != NULL && (p->pindex < end || end == 0);
1795 p = next) {
1796 next = TAILQ_NEXT(p, listq);
1797
1798 if (p->wire_count != 0) {
1799 pmap_remove_all(p);
1800 if (!clean_only)
1801 p->valid = 0;
1802 continue;
1803 }
1804 if (vm_page_sleep_if_busy(p, TRUE, "vmopar"))
1805 goto again;
1806 if (clean_only && p->valid) {
1807 vm_page_test_dirty(p);
1808 if (p->valid & p->dirty)
1809 continue;
1810 }
1811 vm_page_busy(p);
1812 pmap_remove_all(p);
1813 vm_page_free(p);
1814 }
1815 vm_page_unlock_queues();
1816 vm_object_pip_wakeup(object);
1817 }
1818
1819 /*
1820 * Routine: vm_object_coalesce
1821 * Function: Coalesces two objects backing up adjoining
1822 * regions of memory into a single object.
1823 *
1824 * returns TRUE if objects were combined.
1825 *
1826 * NOTE: Only works at the moment if the second object is NULL -
1827 * if it's not, which object do we lock first?
1828 *
1829 * Parameters:
1830 * prev_object First object to coalesce
1831 * prev_offset Offset into prev_object
1832 * next_object Second object into coalesce
1833 * next_offset Offset into next_object
1834 *
1835 * prev_size Size of reference to prev_object
1836 * next_size Size of reference to next_object
1837 *
1838 * Conditions:
1839 * The object must *not* be locked.
1840 */
1841 boolean_t
1842 vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex,
1843 vm_size_t prev_size, vm_size_t next_size)
1844 {
1845 vm_pindex_t next_pindex;
1846
1847 if (prev_object == NULL)
1848 return (TRUE);
1849 VM_OBJECT_LOCK(prev_object);
1850 if (prev_object->type != OBJT_DEFAULT &&
1851 prev_object->type != OBJT_SWAP) {
1852 VM_OBJECT_UNLOCK(prev_object);
1853 return (FALSE);
1854 }
1855
1856 /*
1857 * Try to collapse the object first
1858 */
1859 vm_object_collapse(prev_object);
1860
1861 /*
1862 * Can't coalesce if: . more than one reference . paged out . shadows
1863 * another object . has a copy elsewhere (any of which mean that the
1864 * pages not mapped to prev_entry may be in use anyway)
1865 */
1866 if (prev_object->backing_object != NULL) {
1867 VM_OBJECT_UNLOCK(prev_object);
1868 return (FALSE);
1869 }
1870
1871 prev_size >>= PAGE_SHIFT;
1872 next_size >>= PAGE_SHIFT;
1873 next_pindex = prev_pindex + prev_size;
1874
1875 if ((prev_object->ref_count > 1) &&
1876 (prev_object->size != next_pindex)) {
1877 VM_OBJECT_UNLOCK(prev_object);
1878 return (FALSE);
1879 }
1880
1881 /*
1882 * Remove any pages that may still be in the object from a previous
1883 * deallocation.
1884 */
1885 if (next_pindex < prev_object->size) {
1886 vm_object_page_remove(prev_object,
1887 next_pindex,
1888 next_pindex + next_size, FALSE);
1889 if (prev_object->type == OBJT_SWAP)
1890 swap_pager_freespace(prev_object,
1891 next_pindex, next_size);
1892 }
1893
1894 /*
1895 * Extend the object if necessary.
1896 */
1897 if (next_pindex + next_size > prev_object->size)
1898 prev_object->size = next_pindex + next_size;
1899
1900 VM_OBJECT_UNLOCK(prev_object);
1901 return (TRUE);
1902 }
1903
1904 void
1905 vm_object_set_writeable_dirty(vm_object_t object)
1906 {
1907 struct vnode *vp;
1908
1909 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1910 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1911 if (object->type == OBJT_VNODE &&
1912 (vp = (struct vnode *)object->handle) != NULL) {
1913 VI_LOCK(vp);
1914 if ((vp->v_iflag & VI_OBJDIRTY) == 0)
1915 vp->v_iflag |= VI_OBJDIRTY;
1916 VI_UNLOCK(vp);
1917 }
1918 }
1919
1920 #include "opt_ddb.h"
1921 #ifdef DDB
1922 #include <sys/kernel.h>
1923
1924 #include <sys/cons.h>
1925
1926 #include <ddb/ddb.h>
1927
1928 static int
1929 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1930 {
1931 vm_map_t tmpm;
1932 vm_map_entry_t tmpe;
1933 vm_object_t obj;
1934 int entcount;
1935
1936 if (map == 0)
1937 return 0;
1938
1939 if (entry == 0) {
1940 tmpe = map->header.next;
1941 entcount = map->nentries;
1942 while (entcount-- && (tmpe != &map->header)) {
1943 if (_vm_object_in_map(map, object, tmpe)) {
1944 return 1;
1945 }
1946 tmpe = tmpe->next;
1947 }
1948 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1949 tmpm = entry->object.sub_map;
1950 tmpe = tmpm->header.next;
1951 entcount = tmpm->nentries;
1952 while (entcount-- && tmpe != &tmpm->header) {
1953 if (_vm_object_in_map(tmpm, object, tmpe)) {
1954 return 1;
1955 }
1956 tmpe = tmpe->next;
1957 }
1958 } else if ((obj = entry->object.vm_object) != NULL) {
1959 for (; obj; obj = obj->backing_object)
1960 if (obj == object) {
1961 return 1;
1962 }
1963 }
1964 return 0;
1965 }
1966
1967 static int
1968 vm_object_in_map(vm_object_t object)
1969 {
1970 struct proc *p;
1971
1972 /* sx_slock(&allproc_lock); */
1973 LIST_FOREACH(p, &allproc, p_list) {
1974 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1975 continue;
1976 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1977 /* sx_sunlock(&allproc_lock); */
1978 return 1;
1979 }
1980 }
1981 /* sx_sunlock(&allproc_lock); */
1982 if (_vm_object_in_map(kernel_map, object, 0))
1983 return 1;
1984 if (_vm_object_in_map(kmem_map, object, 0))
1985 return 1;
1986 if (_vm_object_in_map(pager_map, object, 0))
1987 return 1;
1988 if (_vm_object_in_map(buffer_map, object, 0))
1989 return 1;
1990 return 0;
1991 }
1992
1993 DB_SHOW_COMMAND(vmochk, vm_object_check)
1994 {
1995 vm_object_t object;
1996
1997 /*
1998 * make sure that internal objs are in a map somewhere
1999 * and none have zero ref counts.
2000 */
2001 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2002 if (object->handle == NULL &&
2003 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
2004 if (object->ref_count == 0) {
2005 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2006 (long)object->size);
2007 }
2008 if (!vm_object_in_map(object)) {
2009 db_printf(
2010 "vmochk: internal obj is not in a map: "
2011 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2012 object->ref_count, (u_long)object->size,
2013 (u_long)object->size,
2014 (void *)object->backing_object);
2015 }
2016 }
2017 }
2018 }
2019
2020 /*
2021 * vm_object_print: [ debug ]
2022 */
2023 DB_SHOW_COMMAND(object, vm_object_print_static)
2024 {
2025 /* XXX convert args. */
2026 vm_object_t object = (vm_object_t)addr;
2027 boolean_t full = have_addr;
2028
2029 vm_page_t p;
2030
2031 /* XXX count is an (unused) arg. Avoid shadowing it. */
2032 #define count was_count
2033
2034 int count;
2035
2036 if (object == NULL)
2037 return;
2038
2039 db_iprintf(
2040 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n",
2041 object, (int)object->type, (uintmax_t)object->size,
2042 object->resident_page_count, object->ref_count, object->flags);
2043 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
2044 object->shadow_count,
2045 object->backing_object ? object->backing_object->ref_count : 0,
2046 object->backing_object, (uintmax_t)object->backing_object_offset);
2047
2048 if (!full)
2049 return;
2050
2051 db_indent += 2;
2052 count = 0;
2053 TAILQ_FOREACH(p, &object->memq, listq) {
2054 if (count == 0)
2055 db_iprintf("memory:=");
2056 else if (count == 6) {
2057 db_printf("\n");
2058 db_iprintf(" ...");
2059 count = 0;
2060 } else
2061 db_printf(",");
2062 count++;
2063
2064 db_printf("(off=0x%jx,page=0x%jx)",
2065 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
2066 }
2067 if (count != 0)
2068 db_printf("\n");
2069 db_indent -= 2;
2070 }
2071
2072 /* XXX. */
2073 #undef count
2074
2075 /* XXX need this non-static entry for calling from vm_map_print. */
2076 void
2077 vm_object_print(
2078 /* db_expr_t */ long addr,
2079 boolean_t have_addr,
2080 /* db_expr_t */ long count,
2081 char *modif)
2082 {
2083 vm_object_print_static(addr, have_addr, count, modif);
2084 }
2085
2086 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2087 {
2088 vm_object_t object;
2089 int nl = 0;
2090 int c;
2091
2092 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2093 vm_pindex_t idx, fidx;
2094 vm_pindex_t osize;
2095 vm_paddr_t pa = -1, padiff;
2096 int rcount;
2097 vm_page_t m;
2098
2099 db_printf("new object: %p\n", (void *)object);
2100 if (nl > 18) {
2101 c = cngetc();
2102 if (c != ' ')
2103 return;
2104 nl = 0;
2105 }
2106 nl++;
2107 rcount = 0;
2108 fidx = 0;
2109 osize = object->size;
2110 if (osize > 128)
2111 osize = 128;
2112 for (idx = 0; idx < osize; idx++) {
2113 m = vm_page_lookup(object, idx);
2114 if (m == NULL) {
2115 if (rcount) {
2116 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2117 (long)fidx, rcount, (long)pa);
2118 if (nl > 18) {
2119 c = cngetc();
2120 if (c != ' ')
2121 return;
2122 nl = 0;
2123 }
2124 nl++;
2125 rcount = 0;
2126 }
2127 continue;
2128 }
2129
2130
2131 if (rcount &&
2132 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2133 ++rcount;
2134 continue;
2135 }
2136 if (rcount) {
2137 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
2138 padiff >>= PAGE_SHIFT;
2139 padiff &= PQ_L2_MASK;
2140 if (padiff == 0) {
2141 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
2142 ++rcount;
2143 continue;
2144 }
2145 db_printf(" index(%ld)run(%d)pa(0x%lx)",
2146 (long)fidx, rcount, (long)pa);
2147 db_printf("pd(%ld)\n", (long)padiff);
2148 if (nl > 18) {
2149 c = cngetc();
2150 if (c != ' ')
2151 return;
2152 nl = 0;
2153 }
2154 nl++;
2155 }
2156 fidx = idx;
2157 pa = VM_PAGE_TO_PHYS(m);
2158 rcount = 1;
2159 }
2160 if (rcount) {
2161 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2162 (long)fidx, rcount, (long)pa);
2163 if (nl > 18) {
2164 c = cngetc();
2165 if (c != ' ')
2166 return;
2167 nl = 0;
2168 }
2169 nl++;
2170 }
2171 }
2172 }
2173 #endif /* DDB */
Cache object: c0a09bc76e6b383b045392671376fb73
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