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 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94
33 *
34 *
35 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36 * All rights reserved.
37 *
38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39 *
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
45 *
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49 *
50 * Carnegie Mellon requests users of this software to return to
51 *
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
56 *
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
59 */
60
61 /*
62 * Virtual memory object module.
63 */
64
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD: releng/5.4/sys/vm/vm_object.c 142338 2005-02-23 23:06:30Z alc $");
67
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/lock.h>
71 #include <sys/mman.h>
72 #include <sys/mount.h>
73 #include <sys/kernel.h>
74 #include <sys/sysctl.h>
75 #include <sys/mutex.h>
76 #include <sys/proc.h> /* for curproc, pageproc */
77 #include <sys/socket.h>
78 #include <sys/vnode.h>
79 #include <sys/vmmeter.h>
80 #include <sys/sx.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/uma.h>
94
95 #define EASY_SCAN_FACTOR 8
96
97 #define MSYNC_FLUSH_HARDSEQ 0x01
98 #define MSYNC_FLUSH_SOFTSEQ 0x02
99
100 /*
101 * msync / VM object flushing optimizations
102 */
103 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ;
104 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags,
105 CTLFLAG_RW, &msync_flush_flags, 0, "");
106
107 static int old_msync;
108 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
109 "Use old (insecure) msync behavior");
110
111 static void vm_object_qcollapse(vm_object_t object);
112 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags);
113
114 /*
115 * Virtual memory objects maintain the actual data
116 * associated with allocated virtual memory. A given
117 * page of memory exists within exactly one object.
118 *
119 * An object is only deallocated when all "references"
120 * are given up. Only one "reference" to a given
121 * region of an object should be writeable.
122 *
123 * Associated with each object is a list of all resident
124 * memory pages belonging to that object; this list is
125 * maintained by the "vm_page" module, and locked by the object's
126 * lock.
127 *
128 * Each object also records a "pager" routine which is
129 * used to retrieve (and store) pages to the proper backing
130 * storage. In addition, objects may be backed by other
131 * objects from which they were virtual-copied.
132 *
133 * The only items within the object structure which are
134 * modified after time of creation are:
135 * reference count locked by object's lock
136 * pager routine locked by object's lock
137 *
138 */
139
140 struct object_q vm_object_list;
141 struct mtx vm_object_list_mtx; /* lock for object list and count */
142
143 struct vm_object kernel_object_store;
144 struct vm_object kmem_object_store;
145
146 static long object_collapses;
147 static long object_bypasses;
148
149 /*
150 * next_index determines the page color that is assigned to the next
151 * allocated object. Accesses to next_index are not synchronized
152 * because the effects of two or more object allocations using
153 * next_index simultaneously are inconsequential. At any given time,
154 * numerous objects have the same page color.
155 */
156 static int next_index;
157
158 static uma_zone_t obj_zone;
159 #define VM_OBJECTS_INIT 256
160
161 static int vm_object_zinit(void *mem, int size, int flags);
162
163 #ifdef INVARIANTS
164 static void vm_object_zdtor(void *mem, int size, void *arg);
165
166 static void
167 vm_object_zdtor(void *mem, int size, void *arg)
168 {
169 vm_object_t object;
170
171 object = (vm_object_t)mem;
172 KASSERT(TAILQ_EMPTY(&object->memq),
173 ("object %p has resident pages",
174 object));
175 KASSERT(object->paging_in_progress == 0,
176 ("object %p paging_in_progress = %d",
177 object, object->paging_in_progress));
178 KASSERT(object->resident_page_count == 0,
179 ("object %p resident_page_count = %d",
180 object, object->resident_page_count));
181 KASSERT(object->shadow_count == 0,
182 ("object %p shadow_count = %d",
183 object, object->shadow_count));
184 }
185 #endif
186
187 static int
188 vm_object_zinit(void *mem, int size, int flags)
189 {
190 vm_object_t object;
191
192 object = (vm_object_t)mem;
193 bzero(&object->mtx, sizeof(object->mtx));
194 VM_OBJECT_LOCK_INIT(object, "standard object");
195
196 /* These are true for any object that has been freed */
197 object->paging_in_progress = 0;
198 object->resident_page_count = 0;
199 object->shadow_count = 0;
200 return (0);
201 }
202
203 void
204 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object)
205 {
206 int incr;
207
208 TAILQ_INIT(&object->memq);
209 LIST_INIT(&object->shadow_head);
210
211 object->root = NULL;
212 object->type = type;
213 object->size = size;
214 object->generation = 1;
215 object->ref_count = 1;
216 object->flags = 0;
217 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP))
218 object->flags = OBJ_ONEMAPPING;
219 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1))
220 incr = PQ_L2_SIZE / 3 + PQ_PRIME1;
221 else
222 incr = size;
223 object->pg_color = next_index;
224 next_index = (object->pg_color + incr) & PQ_L2_MASK;
225 object->handle = NULL;
226 object->backing_object = NULL;
227 object->backing_object_offset = (vm_ooffset_t) 0;
228
229 mtx_lock(&vm_object_list_mtx);
230 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
231 mtx_unlock(&vm_object_list_mtx);
232 }
233
234 /*
235 * vm_object_init:
236 *
237 * Initialize the VM objects module.
238 */
239 void
240 vm_object_init(void)
241 {
242 TAILQ_INIT(&vm_object_list);
243 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
244
245 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object");
246 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
247 kernel_object);
248
249 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object");
250 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
251 kmem_object);
252
253 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
254 #ifdef INVARIANTS
255 vm_object_zdtor,
256 #else
257 NULL,
258 #endif
259 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE);
260 uma_prealloc(obj_zone, VM_OBJECTS_INIT);
261 }
262
263 void
264 vm_object_clear_flag(vm_object_t object, u_short bits)
265 {
266
267 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
268 object->flags &= ~bits;
269 }
270
271 void
272 vm_object_pip_add(vm_object_t object, short i)
273 {
274
275 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
276 object->paging_in_progress += i;
277 }
278
279 void
280 vm_object_pip_subtract(vm_object_t object, short i)
281 {
282
283 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
284 object->paging_in_progress -= i;
285 }
286
287 void
288 vm_object_pip_wakeup(vm_object_t object)
289 {
290
291 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
292 object->paging_in_progress--;
293 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
294 vm_object_clear_flag(object, OBJ_PIPWNT);
295 wakeup(object);
296 }
297 }
298
299 void
300 vm_object_pip_wakeupn(vm_object_t object, short i)
301 {
302
303 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
304 if (i)
305 object->paging_in_progress -= i;
306 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
307 vm_object_clear_flag(object, OBJ_PIPWNT);
308 wakeup(object);
309 }
310 }
311
312 void
313 vm_object_pip_wait(vm_object_t object, char *waitid)
314 {
315
316 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
317 while (object->paging_in_progress) {
318 object->flags |= OBJ_PIPWNT;
319 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0);
320 }
321 }
322
323 /*
324 * vm_object_allocate_wait
325 *
326 * Return a new object with the given size, and give the user the
327 * option of waiting for it to complete or failing if the needed
328 * memory isn't available.
329 */
330 vm_object_t
331 vm_object_allocate_wait(objtype_t type, vm_pindex_t size, int flags)
332 {
333 vm_object_t result;
334
335 result = (vm_object_t) uma_zalloc(obj_zone, flags);
336
337 if (result != NULL)
338 _vm_object_allocate(type, size, result);
339
340 return (result);
341 }
342
343 /*
344 * vm_object_allocate:
345 *
346 * Returns a new object with the given size.
347 */
348 vm_object_t
349 vm_object_allocate(objtype_t type, vm_pindex_t size)
350 {
351 return(vm_object_allocate_wait(type, size, M_WAITOK));
352 }
353
354
355 /*
356 * vm_object_reference:
357 *
358 * Gets another reference to the given object. Note: OBJ_DEAD
359 * objects can be referenced during final cleaning.
360 */
361 void
362 vm_object_reference(vm_object_t object)
363 {
364 struct vnode *vp;
365 int flags;
366
367 if (object == NULL)
368 return;
369 VM_OBJECT_LOCK(object);
370 object->ref_count++;
371 if (object->type == OBJT_VNODE) {
372 vp = object->handle;
373 VI_LOCK(vp);
374 VM_OBJECT_UNLOCK(object);
375 for (flags = LK_INTERLOCK; vget(vp, flags, curthread);
376 flags = 0)
377 printf("vm_object_reference: delay in vget\n");
378 } else
379 VM_OBJECT_UNLOCK(object);
380 }
381
382 /*
383 * vm_object_reference_locked:
384 *
385 * Gets another reference to the given object.
386 *
387 * The object must be locked.
388 */
389 void
390 vm_object_reference_locked(vm_object_t object)
391 {
392 struct vnode *vp;
393
394 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
395 KASSERT((object->flags & OBJ_DEAD) == 0,
396 ("vm_object_reference_locked: dead object referenced"));
397 object->ref_count++;
398 if (object->type == OBJT_VNODE) {
399 vp = object->handle;
400 vref(vp);
401 }
402 }
403
404 /*
405 * Handle deallocating an object of type OBJT_VNODE.
406 */
407 void
408 vm_object_vndeallocate(vm_object_t object)
409 {
410 struct vnode *vp = (struct vnode *) object->handle;
411
412 GIANT_REQUIRED;
413 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
414 KASSERT(object->type == OBJT_VNODE,
415 ("vm_object_vndeallocate: not a vnode object"));
416 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
417 #ifdef INVARIANTS
418 if (object->ref_count == 0) {
419 vprint("vm_object_vndeallocate", vp);
420 panic("vm_object_vndeallocate: bad object reference count");
421 }
422 #endif
423
424 object->ref_count--;
425 if (object->ref_count == 0) {
426 mp_fixme("Unlocked vflag access.");
427 vp->v_vflag &= ~VV_TEXT;
428 }
429 VM_OBJECT_UNLOCK(object);
430 /*
431 * vrele may need a vop lock
432 */
433 vrele(vp);
434 }
435
436 /*
437 * vm_object_deallocate:
438 *
439 * Release a reference to the specified object,
440 * gained either through a vm_object_allocate
441 * or a vm_object_reference call. When all references
442 * are gone, storage associated with this object
443 * may be relinquished.
444 *
445 * No object may be locked.
446 */
447 void
448 vm_object_deallocate(vm_object_t object)
449 {
450 vm_object_t temp;
451
452 while (object != NULL) {
453 /*
454 * In general, the object should be locked when working with
455 * its type. In this case, in order to maintain proper lock
456 * ordering, an exception is possible because a vnode-backed
457 * object never changes its type.
458 */
459 if (object->type == OBJT_VNODE)
460 mtx_lock(&Giant);
461 VM_OBJECT_LOCK(object);
462 if (object->type == OBJT_VNODE) {
463 vm_object_vndeallocate(object);
464 mtx_unlock(&Giant);
465 return;
466 }
467
468 KASSERT(object->ref_count != 0,
469 ("vm_object_deallocate: object deallocated too many times: %d", object->type));
470
471 /*
472 * If the reference count goes to 0 we start calling
473 * vm_object_terminate() on the object chain.
474 * A ref count of 1 may be a special case depending on the
475 * shadow count being 0 or 1.
476 */
477 object->ref_count--;
478 if (object->ref_count > 1) {
479 VM_OBJECT_UNLOCK(object);
480 return;
481 } else if (object->ref_count == 1) {
482 if (object->shadow_count == 0) {
483 vm_object_set_flag(object, OBJ_ONEMAPPING);
484 } else if ((object->shadow_count == 1) &&
485 (object->handle == NULL) &&
486 (object->type == OBJT_DEFAULT ||
487 object->type == OBJT_SWAP)) {
488 vm_object_t robject;
489
490 robject = LIST_FIRST(&object->shadow_head);
491 KASSERT(robject != NULL,
492 ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
493 object->ref_count,
494 object->shadow_count));
495 if (!VM_OBJECT_TRYLOCK(robject)) {
496 /*
497 * Avoid a potential deadlock.
498 */
499 object->ref_count++;
500 VM_OBJECT_UNLOCK(object);
501 /*
502 * More likely than not the thread
503 * holding robject's lock has lower
504 * priority than the current thread.
505 * Let the lower priority thread run.
506 */
507 tsleep(&proc0, PVM, "vmo_de", 1);
508 continue;
509 }
510 /*
511 * Collapse object into its shadow unless its
512 * shadow is dead. In that case, object will
513 * be deallocated by the thread that is
514 * deallocating its shadow.
515 */
516 if ((robject->flags & OBJ_DEAD) == 0 &&
517 (robject->handle == NULL) &&
518 (robject->type == OBJT_DEFAULT ||
519 robject->type == OBJT_SWAP)) {
520
521 robject->ref_count++;
522 retry:
523 if (robject->paging_in_progress) {
524 VM_OBJECT_UNLOCK(object);
525 vm_object_pip_wait(robject,
526 "objde1");
527 VM_OBJECT_LOCK(object);
528 goto retry;
529 } else if (object->paging_in_progress) {
530 VM_OBJECT_UNLOCK(robject);
531 object->flags |= OBJ_PIPWNT;
532 msleep(object,
533 VM_OBJECT_MTX(object),
534 PDROP | PVM, "objde2", 0);
535 VM_OBJECT_LOCK(robject);
536 VM_OBJECT_LOCK(object);
537 goto retry;
538 }
539 VM_OBJECT_UNLOCK(object);
540 if (robject->ref_count == 1) {
541 robject->ref_count--;
542 object = robject;
543 goto doterm;
544 }
545 object = robject;
546 vm_object_collapse(object);
547 VM_OBJECT_UNLOCK(object);
548 continue;
549 }
550 VM_OBJECT_UNLOCK(robject);
551 }
552 VM_OBJECT_UNLOCK(object);
553 return;
554 }
555 doterm:
556 temp = object->backing_object;
557 if (temp != NULL) {
558 VM_OBJECT_LOCK(temp);
559 LIST_REMOVE(object, shadow_list);
560 temp->shadow_count--;
561 temp->generation++;
562 VM_OBJECT_UNLOCK(temp);
563 object->backing_object = NULL;
564 }
565 /*
566 * Don't double-terminate, we could be in a termination
567 * recursion due to the terminate having to sync data
568 * to disk.
569 */
570 if ((object->flags & OBJ_DEAD) == 0)
571 vm_object_terminate(object);
572 else
573 VM_OBJECT_UNLOCK(object);
574 object = temp;
575 }
576 }
577
578 /*
579 * vm_object_terminate actually destroys the specified object, freeing
580 * up all previously used resources.
581 *
582 * The object must be locked.
583 * This routine may block.
584 */
585 void
586 vm_object_terminate(vm_object_t object)
587 {
588 vm_page_t p;
589
590 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
591
592 /*
593 * Make sure no one uses us.
594 */
595 vm_object_set_flag(object, OBJ_DEAD);
596
597 /*
598 * wait for the pageout daemon to be done with the object
599 */
600 vm_object_pip_wait(object, "objtrm");
601
602 KASSERT(!object->paging_in_progress,
603 ("vm_object_terminate: pageout in progress"));
604
605 /*
606 * Clean and free the pages, as appropriate. All references to the
607 * object are gone, so we don't need to lock it.
608 */
609 if (object->type == OBJT_VNODE) {
610 struct vnode *vp = (struct vnode *)object->handle;
611
612 /*
613 * Clean pages and flush buffers.
614 */
615 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
616 VM_OBJECT_UNLOCK(object);
617
618 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0);
619
620 VM_OBJECT_LOCK(object);
621 }
622
623 KASSERT(object->ref_count == 0,
624 ("vm_object_terminate: object with references, ref_count=%d",
625 object->ref_count));
626
627 /*
628 * Now free any remaining pages. For internal objects, this also
629 * removes them from paging queues. Don't free wired pages, just
630 * remove them from the object.
631 */
632 vm_page_lock_queues();
633 while ((p = TAILQ_FIRST(&object->memq)) != NULL) {
634 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0,
635 ("vm_object_terminate: freeing busy page %p "
636 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags));
637 if (p->wire_count == 0) {
638 vm_page_free(p);
639 cnt.v_pfree++;
640 } else {
641 vm_page_remove(p);
642 }
643 }
644 vm_page_unlock_queues();
645
646 /*
647 * Let the pager know object is dead.
648 */
649 vm_pager_deallocate(object);
650 VM_OBJECT_UNLOCK(object);
651
652 /*
653 * Remove the object from the global object list.
654 */
655 mtx_lock(&vm_object_list_mtx);
656 TAILQ_REMOVE(&vm_object_list, object, object_list);
657 mtx_unlock(&vm_object_list_mtx);
658
659 /*
660 * Free the space for the object.
661 */
662 uma_zfree(obj_zone, object);
663 }
664
665 /*
666 * vm_object_page_clean
667 *
668 * Clean all dirty pages in the specified range of object. Leaves page
669 * on whatever queue it is currently on. If NOSYNC is set then do not
670 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC),
671 * leaving the object dirty.
672 *
673 * When stuffing pages asynchronously, allow clustering. XXX we need a
674 * synchronous clustering mode implementation.
675 *
676 * Odd semantics: if start == end, we clean everything.
677 *
678 * The object must be locked.
679 */
680 void
681 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags)
682 {
683 vm_page_t p, np;
684 vm_pindex_t tstart, tend;
685 vm_pindex_t pi;
686 int clearobjflags;
687 int pagerflags;
688 int curgeneration;
689
690 GIANT_REQUIRED;
691 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
692 if (object->type != OBJT_VNODE ||
693 (object->flags & OBJ_MIGHTBEDIRTY) == 0)
694 return;
695
696 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
697 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0;
698
699 vm_object_set_flag(object, OBJ_CLEANING);
700
701 tstart = start;
702 if (end == 0) {
703 tend = object->size;
704 } else {
705 tend = end;
706 }
707
708 vm_page_lock_queues();
709 /*
710 * If the caller is smart and only msync()s a range he knows is
711 * dirty, we may be able to avoid an object scan. This results in
712 * a phenominal improvement in performance. We cannot do this
713 * as a matter of course because the object may be huge - e.g.
714 * the size might be in the gigabytes or terrabytes.
715 */
716 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) {
717 vm_pindex_t tscan;
718 int scanlimit;
719 int scanreset;
720
721 scanreset = object->resident_page_count / EASY_SCAN_FACTOR;
722 if (scanreset < 16)
723 scanreset = 16;
724 pagerflags |= VM_PAGER_IGNORE_CLEANCHK;
725
726 scanlimit = scanreset;
727 tscan = tstart;
728 while (tscan < tend) {
729 curgeneration = object->generation;
730 p = vm_page_lookup(object, tscan);
731 if (p == NULL || p->valid == 0 ||
732 (p->queue - p->pc) == PQ_CACHE) {
733 if (--scanlimit == 0)
734 break;
735 ++tscan;
736 continue;
737 }
738 vm_page_test_dirty(p);
739 if ((p->dirty & p->valid) == 0) {
740 if (--scanlimit == 0)
741 break;
742 ++tscan;
743 continue;
744 }
745 /*
746 * If we have been asked to skip nosync pages and
747 * this is a nosync page, we can't continue.
748 */
749 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
750 if (--scanlimit == 0)
751 break;
752 ++tscan;
753 continue;
754 }
755 scanlimit = scanreset;
756
757 /*
758 * This returns 0 if it was unable to busy the first
759 * page (i.e. had to sleep).
760 */
761 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags);
762 }
763
764 /*
765 * If everything was dirty and we flushed it successfully,
766 * and the requested range is not the entire object, we
767 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can
768 * return immediately.
769 */
770 if (tscan >= tend && (tstart || tend < object->size)) {
771 vm_page_unlock_queues();
772 vm_object_clear_flag(object, OBJ_CLEANING);
773 return;
774 }
775 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK;
776 }
777
778 /*
779 * Generally set CLEANCHK interlock and make the page read-only so
780 * we can then clear the object flags.
781 *
782 * However, if this is a nosync mmap then the object is likely to
783 * stay dirty so do not mess with the page and do not clear the
784 * object flags.
785 */
786 clearobjflags = 1;
787 TAILQ_FOREACH(p, &object->memq, listq) {
788 vm_page_flag_set(p, PG_CLEANCHK);
789 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC))
790 clearobjflags = 0;
791 else
792 pmap_page_protect(p, VM_PROT_READ);
793 }
794
795 if (clearobjflags && (tstart == 0) && (tend == object->size)) {
796 struct vnode *vp;
797
798 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
799 if (object->type == OBJT_VNODE &&
800 (vp = (struct vnode *)object->handle) != NULL) {
801 VI_LOCK(vp);
802 if (vp->v_iflag & VI_OBJDIRTY)
803 vp->v_iflag &= ~VI_OBJDIRTY;
804 VI_UNLOCK(vp);
805 }
806 }
807
808 rescan:
809 curgeneration = object->generation;
810
811 for (p = TAILQ_FIRST(&object->memq); p; p = np) {
812 int n;
813
814 np = TAILQ_NEXT(p, listq);
815
816 again:
817 pi = p->pindex;
818 if (((p->flags & PG_CLEANCHK) == 0) ||
819 (pi < tstart) || (pi >= tend) ||
820 (p->valid == 0) ||
821 ((p->queue - p->pc) == PQ_CACHE)) {
822 vm_page_flag_clear(p, PG_CLEANCHK);
823 continue;
824 }
825
826 vm_page_test_dirty(p);
827 if ((p->dirty & p->valid) == 0) {
828 vm_page_flag_clear(p, PG_CLEANCHK);
829 continue;
830 }
831
832 /*
833 * If we have been asked to skip nosync pages and this is a
834 * nosync page, skip it. Note that the object flags were
835 * not cleared in this case so we do not have to set them.
836 */
837 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) {
838 vm_page_flag_clear(p, PG_CLEANCHK);
839 continue;
840 }
841
842 n = vm_object_page_collect_flush(object, p,
843 curgeneration, pagerflags);
844 if (n == 0)
845 goto rescan;
846
847 if (object->generation != curgeneration)
848 goto rescan;
849
850 /*
851 * Try to optimize the next page. If we can't we pick up
852 * our (random) scan where we left off.
853 */
854 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) {
855 if ((p = vm_page_lookup(object, pi + n)) != NULL)
856 goto again;
857 }
858 }
859 vm_page_unlock_queues();
860 #if 0
861 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc);
862 #endif
863
864 vm_object_clear_flag(object, OBJ_CLEANING);
865 return;
866 }
867
868 static int
869 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags)
870 {
871 int runlen;
872 int maxf;
873 int chkb;
874 int maxb;
875 int i;
876 vm_pindex_t pi;
877 vm_page_t maf[vm_pageout_page_count];
878 vm_page_t mab[vm_pageout_page_count];
879 vm_page_t ma[vm_pageout_page_count];
880
881 mtx_assert(&vm_page_queue_mtx, MA_OWNED);
882 pi = p->pindex;
883 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) {
884 vm_page_lock_queues();
885 if (object->generation != curgeneration) {
886 return(0);
887 }
888 }
889 maxf = 0;
890 for(i = 1; i < vm_pageout_page_count; i++) {
891 vm_page_t tp;
892
893 if ((tp = vm_page_lookup(object, pi + i)) != NULL) {
894 if ((tp->flags & PG_BUSY) ||
895 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
896 (tp->flags & PG_CLEANCHK) == 0) ||
897 (tp->busy != 0))
898 break;
899 if((tp->queue - tp->pc) == PQ_CACHE) {
900 vm_page_flag_clear(tp, PG_CLEANCHK);
901 break;
902 }
903 vm_page_test_dirty(tp);
904 if ((tp->dirty & tp->valid) == 0) {
905 vm_page_flag_clear(tp, PG_CLEANCHK);
906 break;
907 }
908 maf[ i - 1 ] = tp;
909 maxf++;
910 continue;
911 }
912 break;
913 }
914
915 maxb = 0;
916 chkb = vm_pageout_page_count - maxf;
917 if (chkb) {
918 for(i = 1; i < chkb;i++) {
919 vm_page_t tp;
920
921 if ((tp = vm_page_lookup(object, pi - i)) != NULL) {
922 if ((tp->flags & PG_BUSY) ||
923 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 &&
924 (tp->flags & PG_CLEANCHK) == 0) ||
925 (tp->busy != 0))
926 break;
927 if ((tp->queue - tp->pc) == PQ_CACHE) {
928 vm_page_flag_clear(tp, PG_CLEANCHK);
929 break;
930 }
931 vm_page_test_dirty(tp);
932 if ((tp->dirty & tp->valid) == 0) {
933 vm_page_flag_clear(tp, PG_CLEANCHK);
934 break;
935 }
936 mab[ i - 1 ] = tp;
937 maxb++;
938 continue;
939 }
940 break;
941 }
942 }
943
944 for(i = 0; i < maxb; i++) {
945 int index = (maxb - i) - 1;
946 ma[index] = mab[i];
947 vm_page_flag_clear(ma[index], PG_CLEANCHK);
948 }
949 vm_page_flag_clear(p, PG_CLEANCHK);
950 ma[maxb] = p;
951 for(i = 0; i < maxf; i++) {
952 int index = (maxb + i) + 1;
953 ma[index] = maf[i];
954 vm_page_flag_clear(ma[index], PG_CLEANCHK);
955 }
956 runlen = maxb + maxf + 1;
957
958 vm_pageout_flush(ma, runlen, pagerflags);
959 for (i = 0; i < runlen; i++) {
960 if (ma[i]->valid & ma[i]->dirty) {
961 pmap_page_protect(ma[i], VM_PROT_READ);
962 vm_page_flag_set(ma[i], PG_CLEANCHK);
963
964 /*
965 * maxf will end up being the actual number of pages
966 * we wrote out contiguously, non-inclusive of the
967 * first page. We do not count look-behind pages.
968 */
969 if (i >= maxb + 1 && (maxf > i - maxb - 1))
970 maxf = i - maxb - 1;
971 }
972 }
973 return(maxf + 1);
974 }
975
976 /*
977 * Note that there is absolutely no sense in writing out
978 * anonymous objects, so we track down the vnode object
979 * to write out.
980 * We invalidate (remove) all pages from the address space
981 * for semantic correctness.
982 *
983 * Note: certain anonymous maps, such as MAP_NOSYNC maps,
984 * may start out with a NULL object.
985 */
986 void
987 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
988 boolean_t syncio, boolean_t invalidate)
989 {
990 vm_object_t backing_object;
991 struct vnode *vp;
992 int flags;
993
994 if (object == NULL)
995 return;
996 VM_OBJECT_LOCK(object);
997 while ((backing_object = object->backing_object) != NULL) {
998 VM_OBJECT_LOCK(backing_object);
999 offset += object->backing_object_offset;
1000 VM_OBJECT_UNLOCK(object);
1001 object = backing_object;
1002 if (object->size < OFF_TO_IDX(offset + size))
1003 size = IDX_TO_OFF(object->size) - offset;
1004 }
1005 /*
1006 * Flush pages if writing is allowed, invalidate them
1007 * if invalidation requested. Pages undergoing I/O
1008 * will be ignored by vm_object_page_remove().
1009 *
1010 * We cannot lock the vnode and then wait for paging
1011 * to complete without deadlocking against vm_fault.
1012 * Instead we simply call vm_object_page_remove() and
1013 * allow it to block internally on a page-by-page
1014 * basis when it encounters pages undergoing async
1015 * I/O.
1016 */
1017 if (object->type == OBJT_VNODE &&
1018 (object->flags & OBJ_MIGHTBEDIRTY) != 0) {
1019 vp = object->handle;
1020 VM_OBJECT_UNLOCK(object);
1021 mtx_lock(&Giant);
1022 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
1023 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
1024 flags |= invalidate ? OBJPC_INVAL : 0;
1025 VM_OBJECT_LOCK(object);
1026 vm_object_page_clean(object,
1027 OFF_TO_IDX(offset),
1028 OFF_TO_IDX(offset + size + PAGE_MASK),
1029 flags);
1030 VM_OBJECT_UNLOCK(object);
1031 VOP_UNLOCK(vp, 0, curthread);
1032 mtx_unlock(&Giant);
1033 VM_OBJECT_LOCK(object);
1034 }
1035 if ((object->type == OBJT_VNODE ||
1036 object->type == OBJT_DEVICE) && invalidate) {
1037 boolean_t purge;
1038 purge = old_msync || (object->type == OBJT_DEVICE);
1039 vm_object_page_remove(object,
1040 OFF_TO_IDX(offset),
1041 OFF_TO_IDX(offset + size + PAGE_MASK),
1042 purge ? FALSE : TRUE);
1043 }
1044 VM_OBJECT_UNLOCK(object);
1045 }
1046
1047 /*
1048 * vm_object_madvise:
1049 *
1050 * Implements the madvise function at the object/page level.
1051 *
1052 * MADV_WILLNEED (any object)
1053 *
1054 * Activate the specified pages if they are resident.
1055 *
1056 * MADV_DONTNEED (any object)
1057 *
1058 * Deactivate the specified pages if they are resident.
1059 *
1060 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
1061 * OBJ_ONEMAPPING only)
1062 *
1063 * Deactivate and clean the specified pages if they are
1064 * resident. This permits the process to reuse the pages
1065 * without faulting or the kernel to reclaim the pages
1066 * without I/O.
1067 */
1068 void
1069 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise)
1070 {
1071 vm_pindex_t end, tpindex;
1072 vm_object_t backing_object, tobject;
1073 vm_page_t m;
1074
1075 if (object == NULL)
1076 return;
1077 VM_OBJECT_LOCK(object);
1078 end = pindex + count;
1079 /*
1080 * Locate and adjust resident pages
1081 */
1082 for (; pindex < end; pindex += 1) {
1083 relookup:
1084 tobject = object;
1085 tpindex = pindex;
1086 shadowlookup:
1087 /*
1088 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1089 * and those pages must be OBJ_ONEMAPPING.
1090 */
1091 if (advise == MADV_FREE) {
1092 if ((tobject->type != OBJT_DEFAULT &&
1093 tobject->type != OBJT_SWAP) ||
1094 (tobject->flags & OBJ_ONEMAPPING) == 0) {
1095 goto unlock_tobject;
1096 }
1097 }
1098 m = vm_page_lookup(tobject, tpindex);
1099 if (m == NULL) {
1100 /*
1101 * There may be swap even if there is no backing page
1102 */
1103 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1104 swap_pager_freespace(tobject, tpindex, 1);
1105 /*
1106 * next object
1107 */
1108 backing_object = tobject->backing_object;
1109 if (backing_object == NULL)
1110 goto unlock_tobject;
1111 VM_OBJECT_LOCK(backing_object);
1112 tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1113 if (tobject != object)
1114 VM_OBJECT_UNLOCK(tobject);
1115 tobject = backing_object;
1116 goto shadowlookup;
1117 }
1118 /*
1119 * If the page is busy or not in a normal active state,
1120 * we skip it. If the page is not managed there are no
1121 * page queues to mess with. Things can break if we mess
1122 * with pages in any of the below states.
1123 */
1124 vm_page_lock_queues();
1125 if (m->hold_count ||
1126 m->wire_count ||
1127 (m->flags & PG_UNMANAGED) ||
1128 m->valid != VM_PAGE_BITS_ALL) {
1129 vm_page_unlock_queues();
1130 goto unlock_tobject;
1131 }
1132 if ((m->flags & PG_BUSY) || m->busy) {
1133 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
1134 if (object != tobject)
1135 VM_OBJECT_UNLOCK(object);
1136 VM_OBJECT_UNLOCK(tobject);
1137 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "madvpo", 0);
1138 VM_OBJECT_LOCK(object);
1139 goto relookup;
1140 }
1141 if (advise == MADV_WILLNEED) {
1142 vm_page_activate(m);
1143 } else if (advise == MADV_DONTNEED) {
1144 vm_page_dontneed(m);
1145 } else if (advise == MADV_FREE) {
1146 /*
1147 * Mark the page clean. This will allow the page
1148 * to be freed up by the system. However, such pages
1149 * are often reused quickly by malloc()/free()
1150 * so we do not do anything that would cause
1151 * a page fault if we can help it.
1152 *
1153 * Specifically, we do not try to actually free
1154 * the page now nor do we try to put it in the
1155 * cache (which would cause a page fault on reuse).
1156 *
1157 * But we do make the page is freeable as we
1158 * can without actually taking the step of unmapping
1159 * it.
1160 */
1161 pmap_clear_modify(m);
1162 m->dirty = 0;
1163 m->act_count = 0;
1164 vm_page_dontneed(m);
1165 }
1166 vm_page_unlock_queues();
1167 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1168 swap_pager_freespace(tobject, tpindex, 1);
1169 unlock_tobject:
1170 if (tobject != object)
1171 VM_OBJECT_UNLOCK(tobject);
1172 }
1173 VM_OBJECT_UNLOCK(object);
1174 }
1175
1176 /*
1177 * vm_object_shadow:
1178 *
1179 * Create a new object which is backed by the
1180 * specified existing object range. The source
1181 * object reference is deallocated.
1182 *
1183 * The new object and offset into that object
1184 * are returned in the source parameters.
1185 */
1186 void
1187 vm_object_shadow(
1188 vm_object_t *object, /* IN/OUT */
1189 vm_ooffset_t *offset, /* IN/OUT */
1190 vm_size_t length)
1191 {
1192 vm_object_t source;
1193 vm_object_t result;
1194
1195 source = *object;
1196
1197 /*
1198 * Don't create the new object if the old object isn't shared.
1199 */
1200 if (source != NULL) {
1201 VM_OBJECT_LOCK(source);
1202 if (source->ref_count == 1 &&
1203 source->handle == NULL &&
1204 (source->type == OBJT_DEFAULT ||
1205 source->type == OBJT_SWAP)) {
1206 VM_OBJECT_UNLOCK(source);
1207 return;
1208 }
1209 VM_OBJECT_UNLOCK(source);
1210 }
1211
1212 /*
1213 * Allocate a new object with the given length.
1214 */
1215 result = vm_object_allocate(OBJT_DEFAULT, length);
1216
1217 /*
1218 * The new object shadows the source object, adding a reference to it.
1219 * Our caller changes his reference to point to the new object,
1220 * removing a reference to the source object. Net result: no change
1221 * of reference count.
1222 *
1223 * Try to optimize the result object's page color when shadowing
1224 * in order to maintain page coloring consistency in the combined
1225 * shadowed object.
1226 */
1227 result->backing_object = source;
1228 /*
1229 * Store the offset into the source object, and fix up the offset into
1230 * the new object.
1231 */
1232 result->backing_object_offset = *offset;
1233 if (source != NULL) {
1234 VM_OBJECT_LOCK(source);
1235 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
1236 source->shadow_count++;
1237 source->generation++;
1238 if (length < source->size)
1239 length = source->size;
1240 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 ||
1241 source->generation > 1)
1242 length = PQ_L2_SIZE / 3 + PQ_PRIME1;
1243 result->pg_color = (source->pg_color +
1244 length * source->generation) & PQ_L2_MASK;
1245 VM_OBJECT_UNLOCK(source);
1246 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) &
1247 PQ_L2_MASK;
1248 }
1249
1250
1251 /*
1252 * Return the new things
1253 */
1254 *offset = 0;
1255 *object = result;
1256 }
1257
1258 /*
1259 * vm_object_split:
1260 *
1261 * Split the pages in a map entry into a new object. This affords
1262 * easier removal of unused pages, and keeps object inheritance from
1263 * being a negative impact on memory usage.
1264 */
1265 void
1266 vm_object_split(vm_map_entry_t entry)
1267 {
1268 vm_page_t m;
1269 vm_object_t orig_object, new_object, source;
1270 vm_pindex_t offidxstart, offidxend;
1271 vm_size_t idx, size;
1272
1273 orig_object = entry->object.vm_object;
1274 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
1275 return;
1276 if (orig_object->ref_count <= 1)
1277 return;
1278 VM_OBJECT_UNLOCK(orig_object);
1279
1280 offidxstart = OFF_TO_IDX(entry->offset);
1281 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start);
1282 size = offidxend - offidxstart;
1283
1284 /*
1285 * If swap_pager_copy() is later called, it will convert new_object
1286 * into a swap object.
1287 */
1288 new_object = vm_object_allocate(OBJT_DEFAULT, size);
1289
1290 VM_OBJECT_LOCK(new_object);
1291 VM_OBJECT_LOCK(orig_object);
1292 source = orig_object->backing_object;
1293 if (source != NULL) {
1294 VM_OBJECT_LOCK(source);
1295 LIST_INSERT_HEAD(&source->shadow_head,
1296 new_object, shadow_list);
1297 source->shadow_count++;
1298 source->generation++;
1299 vm_object_reference_locked(source); /* for new_object */
1300 vm_object_clear_flag(source, OBJ_ONEMAPPING);
1301 VM_OBJECT_UNLOCK(source);
1302 new_object->backing_object_offset =
1303 orig_object->backing_object_offset + entry->offset;
1304 new_object->backing_object = source;
1305 }
1306 vm_page_lock_queues();
1307 for (idx = 0; idx < size; idx++) {
1308 retry:
1309 m = vm_page_lookup(orig_object, offidxstart + idx);
1310 if (m == NULL)
1311 continue;
1312
1313 /*
1314 * We must wait for pending I/O to complete before we can
1315 * rename the page.
1316 *
1317 * We do not have to VM_PROT_NONE the page as mappings should
1318 * not be changed by this operation.
1319 */
1320 if ((m->flags & PG_BUSY) || m->busy) {
1321 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
1322 VM_OBJECT_UNLOCK(orig_object);
1323 VM_OBJECT_UNLOCK(new_object);
1324 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0);
1325 VM_OBJECT_LOCK(new_object);
1326 VM_OBJECT_LOCK(orig_object);
1327 vm_page_lock_queues();
1328 goto retry;
1329 }
1330 vm_page_rename(m, new_object, idx);
1331 /* page automatically made dirty by rename and cache handled */
1332 vm_page_busy(m);
1333 }
1334 vm_page_unlock_queues();
1335 if (orig_object->type == OBJT_SWAP) {
1336 /*
1337 * swap_pager_copy() can sleep, in which case the orig_object's
1338 * and new_object's locks are released and reacquired.
1339 */
1340 swap_pager_copy(orig_object, new_object, offidxstart, 0);
1341 }
1342 VM_OBJECT_UNLOCK(orig_object);
1343 vm_page_lock_queues();
1344 TAILQ_FOREACH(m, &new_object->memq, listq)
1345 vm_page_wakeup(m);
1346 vm_page_unlock_queues();
1347 VM_OBJECT_UNLOCK(new_object);
1348 entry->object.vm_object = new_object;
1349 entry->offset = 0LL;
1350 vm_object_deallocate(orig_object);
1351 VM_OBJECT_LOCK(new_object);
1352 }
1353
1354 #define OBSC_TEST_ALL_SHADOWED 0x0001
1355 #define OBSC_COLLAPSE_NOWAIT 0x0002
1356 #define OBSC_COLLAPSE_WAIT 0x0004
1357
1358 static int
1359 vm_object_backing_scan(vm_object_t object, int op)
1360 {
1361 int r = 1;
1362 vm_page_t p;
1363 vm_object_t backing_object;
1364 vm_pindex_t backing_offset_index;
1365
1366 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1367 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED);
1368
1369 backing_object = object->backing_object;
1370 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1371
1372 /*
1373 * Initial conditions
1374 */
1375 if (op & OBSC_TEST_ALL_SHADOWED) {
1376 /*
1377 * We do not want to have to test for the existence of
1378 * swap pages in the backing object. XXX but with the
1379 * new swapper this would be pretty easy to do.
1380 *
1381 * XXX what about anonymous MAP_SHARED memory that hasn't
1382 * been ZFOD faulted yet? If we do not test for this, the
1383 * shadow test may succeed! XXX
1384 */
1385 if (backing_object->type != OBJT_DEFAULT) {
1386 return (0);
1387 }
1388 }
1389 if (op & OBSC_COLLAPSE_WAIT) {
1390 vm_object_set_flag(backing_object, OBJ_DEAD);
1391 }
1392
1393 /*
1394 * Our scan
1395 */
1396 p = TAILQ_FIRST(&backing_object->memq);
1397 while (p) {
1398 vm_page_t next = TAILQ_NEXT(p, listq);
1399 vm_pindex_t new_pindex = p->pindex - backing_offset_index;
1400
1401 if (op & OBSC_TEST_ALL_SHADOWED) {
1402 vm_page_t pp;
1403
1404 /*
1405 * Ignore pages outside the parent object's range
1406 * and outside the parent object's mapping of the
1407 * backing object.
1408 *
1409 * note that we do not busy the backing object's
1410 * page.
1411 */
1412 if (
1413 p->pindex < backing_offset_index ||
1414 new_pindex >= object->size
1415 ) {
1416 p = next;
1417 continue;
1418 }
1419
1420 /*
1421 * See if the parent has the page or if the parent's
1422 * object pager has the page. If the parent has the
1423 * page but the page is not valid, the parent's
1424 * object pager must have the page.
1425 *
1426 * If this fails, the parent does not completely shadow
1427 * the object and we might as well give up now.
1428 */
1429
1430 pp = vm_page_lookup(object, new_pindex);
1431 if (
1432 (pp == NULL || pp->valid == 0) &&
1433 !vm_pager_has_page(object, new_pindex, NULL, NULL)
1434 ) {
1435 r = 0;
1436 break;
1437 }
1438 }
1439
1440 /*
1441 * Check for busy page
1442 */
1443 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1444 vm_page_t pp;
1445
1446 vm_page_lock_queues();
1447 if (op & OBSC_COLLAPSE_NOWAIT) {
1448 if ((p->flags & PG_BUSY) ||
1449 !p->valid ||
1450 p->hold_count ||
1451 p->wire_count ||
1452 p->busy) {
1453 vm_page_unlock_queues();
1454 p = next;
1455 continue;
1456 }
1457 } else if (op & OBSC_COLLAPSE_WAIT) {
1458 if ((p->flags & PG_BUSY) || p->busy) {
1459 vm_page_flag_set(p,
1460 PG_WANTED | PG_REFERENCED);
1461 VM_OBJECT_UNLOCK(backing_object);
1462 VM_OBJECT_UNLOCK(object);
1463 msleep(p, &vm_page_queue_mtx,
1464 PDROP | PVM, "vmocol", 0);
1465 VM_OBJECT_LOCK(object);
1466 VM_OBJECT_LOCK(backing_object);
1467 /*
1468 * If we slept, anything could have
1469 * happened. Since the object is
1470 * marked dead, the backing offset
1471 * should not have changed so we
1472 * just restart our scan.
1473 */
1474 p = TAILQ_FIRST(&backing_object->memq);
1475 continue;
1476 }
1477 }
1478
1479 /*
1480 * Busy the page
1481 */
1482 vm_page_busy(p);
1483 vm_page_unlock_queues();
1484
1485 KASSERT(
1486 p->object == backing_object,
1487 ("vm_object_backing_scan: object mismatch")
1488 );
1489
1490 /*
1491 * Destroy any associated swap
1492 */
1493 if (backing_object->type == OBJT_SWAP) {
1494 swap_pager_freespace(
1495 backing_object,
1496 p->pindex,
1497 1
1498 );
1499 }
1500
1501 if (
1502 p->pindex < backing_offset_index ||
1503 new_pindex >= object->size
1504 ) {
1505 /*
1506 * Page is out of the parent object's range, we
1507 * can simply destroy it.
1508 */
1509 vm_page_lock_queues();
1510 pmap_remove_all(p);
1511 vm_page_free(p);
1512 vm_page_unlock_queues();
1513 p = next;
1514 continue;
1515 }
1516
1517 pp = vm_page_lookup(object, new_pindex);
1518 if (
1519 pp != NULL ||
1520 vm_pager_has_page(object, new_pindex, NULL, NULL)
1521 ) {
1522 /*
1523 * page already exists in parent OR swap exists
1524 * for this location in the parent. Destroy
1525 * the original page from the backing object.
1526 *
1527 * Leave the parent's page alone
1528 */
1529 vm_page_lock_queues();
1530 pmap_remove_all(p);
1531 vm_page_free(p);
1532 vm_page_unlock_queues();
1533 p = next;
1534 continue;
1535 }
1536
1537 /*
1538 * Page does not exist in parent, rename the
1539 * page from the backing object to the main object.
1540 *
1541 * If the page was mapped to a process, it can remain
1542 * mapped through the rename.
1543 */
1544 vm_page_lock_queues();
1545 vm_page_rename(p, object, new_pindex);
1546 vm_page_unlock_queues();
1547 /* page automatically made dirty by rename */
1548 }
1549 p = next;
1550 }
1551 return (r);
1552 }
1553
1554
1555 /*
1556 * this version of collapse allows the operation to occur earlier and
1557 * when paging_in_progress is true for an object... This is not a complete
1558 * operation, but should plug 99.9% of the rest of the leaks.
1559 */
1560 static void
1561 vm_object_qcollapse(vm_object_t object)
1562 {
1563 vm_object_t backing_object = object->backing_object;
1564
1565 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1566 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED);
1567
1568 if (backing_object->ref_count != 1)
1569 return;
1570
1571 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1572 }
1573
1574 /*
1575 * vm_object_collapse:
1576 *
1577 * Collapse an object with the object backing it.
1578 * Pages in the backing object are moved into the
1579 * parent, and the backing object is deallocated.
1580 */
1581 void
1582 vm_object_collapse(vm_object_t object)
1583 {
1584 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1585
1586 while (TRUE) {
1587 vm_object_t backing_object;
1588
1589 /*
1590 * Verify that the conditions are right for collapse:
1591 *
1592 * The object exists and the backing object exists.
1593 */
1594 if ((backing_object = object->backing_object) == NULL)
1595 break;
1596
1597 /*
1598 * we check the backing object first, because it is most likely
1599 * not collapsable.
1600 */
1601 VM_OBJECT_LOCK(backing_object);
1602 if (backing_object->handle != NULL ||
1603 (backing_object->type != OBJT_DEFAULT &&
1604 backing_object->type != OBJT_SWAP) ||
1605 (backing_object->flags & OBJ_DEAD) ||
1606 object->handle != NULL ||
1607 (object->type != OBJT_DEFAULT &&
1608 object->type != OBJT_SWAP) ||
1609 (object->flags & OBJ_DEAD)) {
1610 VM_OBJECT_UNLOCK(backing_object);
1611 break;
1612 }
1613
1614 if (
1615 object->paging_in_progress != 0 ||
1616 backing_object->paging_in_progress != 0
1617 ) {
1618 vm_object_qcollapse(object);
1619 VM_OBJECT_UNLOCK(backing_object);
1620 break;
1621 }
1622 /*
1623 * We know that we can either collapse the backing object (if
1624 * the parent is the only reference to it) or (perhaps) have
1625 * the parent bypass the object if the parent happens to shadow
1626 * all the resident pages in the entire backing object.
1627 *
1628 * This is ignoring pager-backed pages such as swap pages.
1629 * vm_object_backing_scan fails the shadowing test in this
1630 * case.
1631 */
1632 if (backing_object->ref_count == 1) {
1633 /*
1634 * If there is exactly one reference to the backing
1635 * object, we can collapse it into the parent.
1636 */
1637 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1638
1639 /*
1640 * Move the pager from backing_object to object.
1641 */
1642 if (backing_object->type == OBJT_SWAP) {
1643 /*
1644 * swap_pager_copy() can sleep, in which case
1645 * the backing_object's and object's locks are
1646 * released and reacquired.
1647 */
1648 swap_pager_copy(
1649 backing_object,
1650 object,
1651 OFF_TO_IDX(object->backing_object_offset), TRUE);
1652 }
1653 /*
1654 * Object now shadows whatever backing_object did.
1655 * Note that the reference to
1656 * backing_object->backing_object moves from within
1657 * backing_object to within object.
1658 */
1659 LIST_REMOVE(object, shadow_list);
1660 backing_object->shadow_count--;
1661 backing_object->generation++;
1662 if (backing_object->backing_object) {
1663 VM_OBJECT_LOCK(backing_object->backing_object);
1664 LIST_REMOVE(backing_object, shadow_list);
1665 LIST_INSERT_HEAD(
1666 &backing_object->backing_object->shadow_head,
1667 object, shadow_list);
1668 /*
1669 * The shadow_count has not changed.
1670 */
1671 backing_object->backing_object->generation++;
1672 VM_OBJECT_UNLOCK(backing_object->backing_object);
1673 }
1674 object->backing_object = backing_object->backing_object;
1675 object->backing_object_offset +=
1676 backing_object->backing_object_offset;
1677
1678 /*
1679 * Discard backing_object.
1680 *
1681 * Since the backing object has no pages, no pager left,
1682 * and no object references within it, all that is
1683 * necessary is to dispose of it.
1684 */
1685 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
1686 VM_OBJECT_UNLOCK(backing_object);
1687
1688 mtx_lock(&vm_object_list_mtx);
1689 TAILQ_REMOVE(
1690 &vm_object_list,
1691 backing_object,
1692 object_list
1693 );
1694 mtx_unlock(&vm_object_list_mtx);
1695
1696 uma_zfree(obj_zone, backing_object);
1697
1698 object_collapses++;
1699 } else {
1700 vm_object_t new_backing_object;
1701
1702 /*
1703 * If we do not entirely shadow the backing object,
1704 * there is nothing we can do so we give up.
1705 */
1706 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) {
1707 VM_OBJECT_UNLOCK(backing_object);
1708 break;
1709 }
1710
1711 /*
1712 * Make the parent shadow the next object in the
1713 * chain. Deallocating backing_object will not remove
1714 * it, since its reference count is at least 2.
1715 */
1716 LIST_REMOVE(object, shadow_list);
1717 backing_object->shadow_count--;
1718 backing_object->generation++;
1719
1720 new_backing_object = backing_object->backing_object;
1721 if ((object->backing_object = new_backing_object) != NULL) {
1722 VM_OBJECT_LOCK(new_backing_object);
1723 LIST_INSERT_HEAD(
1724 &new_backing_object->shadow_head,
1725 object,
1726 shadow_list
1727 );
1728 new_backing_object->shadow_count++;
1729 new_backing_object->generation++;
1730 vm_object_reference_locked(new_backing_object);
1731 VM_OBJECT_UNLOCK(new_backing_object);
1732 object->backing_object_offset +=
1733 backing_object->backing_object_offset;
1734 }
1735
1736 /*
1737 * Drop the reference count on backing_object. Since
1738 * its ref_count was at least 2, it will not vanish.
1739 */
1740 backing_object->ref_count--;
1741 VM_OBJECT_UNLOCK(backing_object);
1742 object_bypasses++;
1743 }
1744
1745 /*
1746 * Try again with this object's new backing object.
1747 */
1748 }
1749 }
1750
1751 /*
1752 * vm_object_page_remove:
1753 *
1754 * Removes all physical pages in the given range from the
1755 * object's list of pages. If the range's end is zero, all
1756 * physical pages from the range's start to the end of the object
1757 * are deleted.
1758 *
1759 * The object must be locked.
1760 */
1761 void
1762 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
1763 boolean_t clean_only)
1764 {
1765 vm_page_t p, next;
1766
1767 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1768 if (object->resident_page_count == 0)
1769 return;
1770
1771 /*
1772 * Since physically-backed objects do not use managed pages, we can't
1773 * remove pages from the object (we must instead remove the page
1774 * references, and then destroy the object).
1775 */
1776 KASSERT(object->type != OBJT_PHYS,
1777 ("attempt to remove pages from a physical object"));
1778
1779 vm_object_pip_add(object, 1);
1780 again:
1781 vm_page_lock_queues();
1782 if ((p = TAILQ_FIRST(&object->memq)) != NULL) {
1783 if (p->pindex < start) {
1784 p = vm_page_splay(start, object->root);
1785 if ((object->root = p)->pindex < start)
1786 p = TAILQ_NEXT(p, listq);
1787 }
1788 }
1789 /*
1790 * Assert: the variable p is either (1) the page with the
1791 * least pindex greater than or equal to the parameter pindex
1792 * or (2) NULL.
1793 */
1794 for (;
1795 p != NULL && (p->pindex < end || end == 0);
1796 p = next) {
1797 next = TAILQ_NEXT(p, listq);
1798
1799 if (p->wire_count != 0) {
1800 pmap_remove_all(p);
1801 if (!clean_only)
1802 p->valid = 0;
1803 continue;
1804 }
1805 if (vm_page_sleep_if_busy(p, TRUE, "vmopar"))
1806 goto again;
1807 if (clean_only && p->valid) {
1808 pmap_page_protect(p, VM_PROT_READ | VM_PROT_EXECUTE);
1809 if (p->valid & p->dirty)
1810 continue;
1811 }
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 * prev_size Size of reference to prev_object
1833 * next_size Size of reference to the second object
1834 *
1835 * Conditions:
1836 * The object must *not* be locked.
1837 */
1838 boolean_t
1839 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset,
1840 vm_size_t prev_size, vm_size_t next_size)
1841 {
1842 vm_pindex_t next_pindex;
1843
1844 if (prev_object == NULL)
1845 return (TRUE);
1846 VM_OBJECT_LOCK(prev_object);
1847 if (prev_object->type != OBJT_DEFAULT &&
1848 prev_object->type != OBJT_SWAP) {
1849 VM_OBJECT_UNLOCK(prev_object);
1850 return (FALSE);
1851 }
1852
1853 /*
1854 * Try to collapse the object first
1855 */
1856 vm_object_collapse(prev_object);
1857
1858 /*
1859 * Can't coalesce if: . more than one reference . paged out . shadows
1860 * another object . has a copy elsewhere (any of which mean that the
1861 * pages not mapped to prev_entry may be in use anyway)
1862 */
1863 if (prev_object->backing_object != NULL) {
1864 VM_OBJECT_UNLOCK(prev_object);
1865 return (FALSE);
1866 }
1867
1868 prev_size >>= PAGE_SHIFT;
1869 next_size >>= PAGE_SHIFT;
1870 next_pindex = OFF_TO_IDX(prev_offset) + prev_size;
1871
1872 if ((prev_object->ref_count > 1) &&
1873 (prev_object->size != next_pindex)) {
1874 VM_OBJECT_UNLOCK(prev_object);
1875 return (FALSE);
1876 }
1877
1878 /*
1879 * Remove any pages that may still be in the object from a previous
1880 * deallocation.
1881 */
1882 if (next_pindex < prev_object->size) {
1883 vm_object_page_remove(prev_object,
1884 next_pindex,
1885 next_pindex + next_size, FALSE);
1886 if (prev_object->type == OBJT_SWAP)
1887 swap_pager_freespace(prev_object,
1888 next_pindex, next_size);
1889 }
1890
1891 /*
1892 * Extend the object if necessary.
1893 */
1894 if (next_pindex + next_size > prev_object->size)
1895 prev_object->size = next_pindex + next_size;
1896
1897 VM_OBJECT_UNLOCK(prev_object);
1898 return (TRUE);
1899 }
1900
1901 void
1902 vm_object_set_writeable_dirty(vm_object_t object)
1903 {
1904 struct vnode *vp;
1905
1906 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
1907 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
1908 if (object->type == OBJT_VNODE &&
1909 (vp = (struct vnode *)object->handle) != NULL) {
1910 VI_LOCK(vp);
1911 if ((vp->v_iflag & VI_OBJDIRTY) == 0)
1912 vp->v_iflag |= VI_OBJDIRTY;
1913 VI_UNLOCK(vp);
1914 }
1915 }
1916
1917 #include "opt_ddb.h"
1918 #ifdef DDB
1919 #include <sys/kernel.h>
1920
1921 #include <sys/cons.h>
1922
1923 #include <ddb/ddb.h>
1924
1925 static int
1926 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
1927 {
1928 vm_map_t tmpm;
1929 vm_map_entry_t tmpe;
1930 vm_object_t obj;
1931 int entcount;
1932
1933 if (map == 0)
1934 return 0;
1935
1936 if (entry == 0) {
1937 tmpe = map->header.next;
1938 entcount = map->nentries;
1939 while (entcount-- && (tmpe != &map->header)) {
1940 if (_vm_object_in_map(map, object, tmpe)) {
1941 return 1;
1942 }
1943 tmpe = tmpe->next;
1944 }
1945 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
1946 tmpm = entry->object.sub_map;
1947 tmpe = tmpm->header.next;
1948 entcount = tmpm->nentries;
1949 while (entcount-- && tmpe != &tmpm->header) {
1950 if (_vm_object_in_map(tmpm, object, tmpe)) {
1951 return 1;
1952 }
1953 tmpe = tmpe->next;
1954 }
1955 } else if ((obj = entry->object.vm_object) != NULL) {
1956 for (; obj; obj = obj->backing_object)
1957 if (obj == object) {
1958 return 1;
1959 }
1960 }
1961 return 0;
1962 }
1963
1964 static int
1965 vm_object_in_map(vm_object_t object)
1966 {
1967 struct proc *p;
1968
1969 /* sx_slock(&allproc_lock); */
1970 LIST_FOREACH(p, &allproc, p_list) {
1971 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
1972 continue;
1973 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
1974 /* sx_sunlock(&allproc_lock); */
1975 return 1;
1976 }
1977 }
1978 /* sx_sunlock(&allproc_lock); */
1979 if (_vm_object_in_map(kernel_map, object, 0))
1980 return 1;
1981 if (_vm_object_in_map(kmem_map, object, 0))
1982 return 1;
1983 if (_vm_object_in_map(pager_map, object, 0))
1984 return 1;
1985 if (_vm_object_in_map(buffer_map, object, 0))
1986 return 1;
1987 return 0;
1988 }
1989
1990 DB_SHOW_COMMAND(vmochk, vm_object_check)
1991 {
1992 vm_object_t object;
1993
1994 /*
1995 * make sure that internal objs are in a map somewhere
1996 * and none have zero ref counts.
1997 */
1998 TAILQ_FOREACH(object, &vm_object_list, object_list) {
1999 if (object->handle == NULL &&
2000 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
2001 if (object->ref_count == 0) {
2002 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2003 (long)object->size);
2004 }
2005 if (!vm_object_in_map(object)) {
2006 db_printf(
2007 "vmochk: internal obj is not in a map: "
2008 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2009 object->ref_count, (u_long)object->size,
2010 (u_long)object->size,
2011 (void *)object->backing_object);
2012 }
2013 }
2014 }
2015 }
2016
2017 /*
2018 * vm_object_print: [ debug ]
2019 */
2020 DB_SHOW_COMMAND(object, vm_object_print_static)
2021 {
2022 /* XXX convert args. */
2023 vm_object_t object = (vm_object_t)addr;
2024 boolean_t full = have_addr;
2025
2026 vm_page_t p;
2027
2028 /* XXX count is an (unused) arg. Avoid shadowing it. */
2029 #define count was_count
2030
2031 int count;
2032
2033 if (object == NULL)
2034 return;
2035
2036 db_iprintf(
2037 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n",
2038 object, (int)object->type, (uintmax_t)object->size,
2039 object->resident_page_count, object->ref_count, object->flags);
2040 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
2041 object->shadow_count,
2042 object->backing_object ? object->backing_object->ref_count : 0,
2043 object->backing_object, (uintmax_t)object->backing_object_offset);
2044
2045 if (!full)
2046 return;
2047
2048 db_indent += 2;
2049 count = 0;
2050 TAILQ_FOREACH(p, &object->memq, listq) {
2051 if (count == 0)
2052 db_iprintf("memory:=");
2053 else if (count == 6) {
2054 db_printf("\n");
2055 db_iprintf(" ...");
2056 count = 0;
2057 } else
2058 db_printf(",");
2059 count++;
2060
2061 db_printf("(off=0x%jx,page=0x%jx)",
2062 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
2063 }
2064 if (count != 0)
2065 db_printf("\n");
2066 db_indent -= 2;
2067 }
2068
2069 /* XXX. */
2070 #undef count
2071
2072 /* XXX need this non-static entry for calling from vm_map_print. */
2073 void
2074 vm_object_print(
2075 /* db_expr_t */ long addr,
2076 boolean_t have_addr,
2077 /* db_expr_t */ long count,
2078 char *modif)
2079 {
2080 vm_object_print_static(addr, have_addr, count, modif);
2081 }
2082
2083 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2084 {
2085 vm_object_t object;
2086 int nl = 0;
2087 int c;
2088
2089 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2090 vm_pindex_t idx, fidx;
2091 vm_pindex_t osize;
2092 vm_paddr_t pa = -1, padiff;
2093 int rcount;
2094 vm_page_t m;
2095
2096 db_printf("new object: %p\n", (void *)object);
2097 if (nl > 18) {
2098 c = cngetc();
2099 if (c != ' ')
2100 return;
2101 nl = 0;
2102 }
2103 nl++;
2104 rcount = 0;
2105 fidx = 0;
2106 osize = object->size;
2107 if (osize > 128)
2108 osize = 128;
2109 for (idx = 0; idx < osize; idx++) {
2110 m = vm_page_lookup(object, idx);
2111 if (m == NULL) {
2112 if (rcount) {
2113 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2114 (long)fidx, rcount, (long)pa);
2115 if (nl > 18) {
2116 c = cngetc();
2117 if (c != ' ')
2118 return;
2119 nl = 0;
2120 }
2121 nl++;
2122 rcount = 0;
2123 }
2124 continue;
2125 }
2126
2127
2128 if (rcount &&
2129 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2130 ++rcount;
2131 continue;
2132 }
2133 if (rcount) {
2134 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m);
2135 padiff >>= PAGE_SHIFT;
2136 padiff &= PQ_L2_MASK;
2137 if (padiff == 0) {
2138 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE;
2139 ++rcount;
2140 continue;
2141 }
2142 db_printf(" index(%ld)run(%d)pa(0x%lx)",
2143 (long)fidx, rcount, (long)pa);
2144 db_printf("pd(%ld)\n", (long)padiff);
2145 if (nl > 18) {
2146 c = cngetc();
2147 if (c != ' ')
2148 return;
2149 nl = 0;
2150 }
2151 nl++;
2152 }
2153 fidx = idx;
2154 pa = VM_PAGE_TO_PHYS(m);
2155 rcount = 1;
2156 }
2157 if (rcount) {
2158 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2159 (long)fidx, rcount, (long)pa);
2160 if (nl > 18) {
2161 c = cngetc();
2162 if (c != ' ')
2163 return;
2164 nl = 0;
2165 }
2166 nl++;
2167 }
2168 }
2169 }
2170 #endif /* DDB */
Cache object: 621884dd3acd3e770ea103eedce7be3e
|