Commit | Line | Data |
---|---|---|
175f072e | 1 | /* |
175f072e KM |
2 | * Copyright (c) 1991 Regents of the University of California. |
3 | * 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 | * | |
0e24ad83 | 8 | * %sccs.include.redist.c% |
175f072e | 9 | * |
888963d8 | 10 | * @(#)vm_object.c 7.8 (Berkeley) %G% |
0e24ad83 KM |
11 | * |
12 | * | |
13 | * Copyright (c) 1987, 1990 Carnegie-Mellon University. | |
14 | * All rights reserved. | |
15 | * | |
16 | * Authors: Avadis Tevanian, Jr., Michael Wayne Young | |
17 | * | |
18 | * Permission to use, copy, modify and distribute this software and | |
19 | * its documentation is hereby granted, provided that both the copyright | |
20 | * notice and this permission notice appear in all copies of the | |
21 | * software, derivative works or modified versions, and any portions | |
22 | * thereof, and that both notices appear in supporting documentation. | |
23 | * | |
24 | * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" | |
25 | * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND | |
26 | * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. | |
27 | * | |
28 | * Carnegie Mellon requests users of this software to return to | |
29 | * | |
30 | * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU | |
31 | * School of Computer Science | |
32 | * Carnegie Mellon University | |
33 | * Pittsburgh PA 15213-3890 | |
34 | * | |
35 | * any improvements or extensions that they make and grant Carnegie the | |
36 | * rights to redistribute these changes. | |
175f072e KM |
37 | */ |
38 | ||
39 | /* | |
40 | * Virtual memory object module. | |
41 | */ | |
42 | ||
43 | #include "param.h" | |
44 | #include "malloc.h" | |
ffe0d082 MK |
45 | |
46 | #include "vm.h" | |
47 | #include "vm_page.h" | |
175f072e KM |
48 | |
49 | /* | |
50 | * Virtual memory objects maintain the actual data | |
51 | * associated with allocated virtual memory. A given | |
52 | * page of memory exists within exactly one object. | |
53 | * | |
54 | * An object is only deallocated when all "references" | |
55 | * are given up. Only one "reference" to a given | |
56 | * region of an object should be writeable. | |
57 | * | |
58 | * Associated with each object is a list of all resident | |
59 | * memory pages belonging to that object; this list is | |
60 | * maintained by the "vm_page" module, and locked by the object's | |
61 | * lock. | |
62 | * | |
63 | * Each object also records a "pager" routine which is | |
64 | * used to retrieve (and store) pages to the proper backing | |
65 | * storage. In addition, objects may be backed by other | |
66 | * objects from which they were virtual-copied. | |
67 | * | |
68 | * The only items within the object structure which are | |
69 | * modified after time of creation are: | |
70 | * reference count locked by object's lock | |
71 | * pager routine locked by object's lock | |
72 | * | |
73 | */ | |
74 | ||
75 | struct vm_object kernel_object_store; | |
76 | struct vm_object kmem_object_store; | |
77 | ||
78 | #define VM_OBJECT_HASH_COUNT 157 | |
79 | ||
80 | int vm_cache_max = 100; /* can patch if necessary */ | |
81 | queue_head_t vm_object_hashtable[VM_OBJECT_HASH_COUNT]; | |
82 | ||
83 | long object_collapses = 0; | |
84 | long object_bypasses = 0; | |
85 | ||
86 | /* | |
87 | * vm_object_init: | |
88 | * | |
89 | * Initialize the VM objects module. | |
90 | */ | |
91 | void vm_object_init() | |
92 | { | |
93 | register int i; | |
94 | ||
95 | queue_init(&vm_object_cached_list); | |
96 | queue_init(&vm_object_list); | |
97 | vm_object_count = 0; | |
98 | simple_lock_init(&vm_cache_lock); | |
99 | simple_lock_init(&vm_object_list_lock); | |
100 | ||
101 | for (i = 0; i < VM_OBJECT_HASH_COUNT; i++) | |
102 | queue_init(&vm_object_hashtable[i]); | |
103 | ||
104 | kernel_object = &kernel_object_store; | |
105 | _vm_object_allocate(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS, | |
106 | kernel_object); | |
107 | ||
108 | kmem_object = &kmem_object_store; | |
109 | _vm_object_allocate(VM_KMEM_SIZE + VM_MBUF_SIZE, kmem_object); | |
110 | } | |
111 | ||
112 | /* | |
113 | * vm_object_allocate: | |
114 | * | |
115 | * Returns a new object with the given size. | |
116 | */ | |
117 | ||
118 | vm_object_t vm_object_allocate(size) | |
119 | vm_size_t size; | |
120 | { | |
121 | register vm_object_t result; | |
122 | ||
123 | result = (vm_object_t) | |
124 | malloc((u_long)sizeof *result, M_VMOBJ, M_WAITOK); | |
125 | ||
126 | _vm_object_allocate(size, result); | |
127 | ||
128 | return(result); | |
129 | } | |
130 | ||
131 | _vm_object_allocate(size, object) | |
132 | vm_size_t size; | |
133 | register vm_object_t object; | |
134 | { | |
135 | queue_init(&object->memq); | |
136 | vm_object_lock_init(object); | |
137 | object->ref_count = 1; | |
138 | object->resident_page_count = 0; | |
139 | object->size = size; | |
d4ab8fb9 | 140 | object->flags = OBJ_INTERNAL; /* vm_allocate_with_pager will reset */ |
175f072e | 141 | object->paging_in_progress = 0; |
ffe0d082 | 142 | object->copy = NULL; |
175f072e KM |
143 | |
144 | /* | |
145 | * Object starts out read-write, with no pager. | |
146 | */ | |
147 | ||
ffe0d082 | 148 | object->pager = NULL; |
175f072e | 149 | object->paging_offset = 0; |
ffe0d082 | 150 | object->shadow = NULL; |
175f072e KM |
151 | object->shadow_offset = (vm_offset_t) 0; |
152 | ||
153 | simple_lock(&vm_object_list_lock); | |
154 | queue_enter(&vm_object_list, object, vm_object_t, object_list); | |
155 | vm_object_count++; | |
156 | simple_unlock(&vm_object_list_lock); | |
157 | } | |
158 | ||
159 | /* | |
160 | * vm_object_reference: | |
161 | * | |
162 | * Gets another reference to the given object. | |
163 | */ | |
164 | void vm_object_reference(object) | |
165 | register vm_object_t object; | |
166 | { | |
ffe0d082 | 167 | if (object == NULL) |
175f072e KM |
168 | return; |
169 | ||
170 | vm_object_lock(object); | |
171 | object->ref_count++; | |
172 | vm_object_unlock(object); | |
173 | } | |
174 | ||
175 | /* | |
176 | * vm_object_deallocate: | |
177 | * | |
178 | * Release a reference to the specified object, | |
179 | * gained either through a vm_object_allocate | |
180 | * or a vm_object_reference call. When all references | |
181 | * are gone, storage associated with this object | |
182 | * may be relinquished. | |
183 | * | |
184 | * No object may be locked. | |
185 | */ | |
186 | void vm_object_deallocate(object) | |
187 | register vm_object_t object; | |
188 | { | |
189 | vm_object_t temp; | |
190 | ||
ffe0d082 | 191 | while (object != NULL) { |
175f072e KM |
192 | |
193 | /* | |
194 | * The cache holds a reference (uncounted) to | |
195 | * the object; we must lock it before removing | |
196 | * the object. | |
197 | */ | |
198 | ||
199 | vm_object_cache_lock(); | |
200 | ||
201 | /* | |
202 | * Lose the reference | |
203 | */ | |
204 | vm_object_lock(object); | |
205 | if (--(object->ref_count) != 0) { | |
206 | ||
207 | /* | |
208 | * If there are still references, then | |
209 | * we are done. | |
210 | */ | |
211 | vm_object_unlock(object); | |
212 | vm_object_cache_unlock(); | |
213 | return; | |
214 | } | |
215 | ||
216 | /* | |
217 | * See if this object can persist. If so, enter | |
218 | * it in the cache, then deactivate all of its | |
219 | * pages. | |
220 | */ | |
221 | ||
d4ab8fb9 | 222 | if (object->flags & OBJ_CANPERSIST) { |
175f072e KM |
223 | |
224 | queue_enter(&vm_object_cached_list, object, | |
225 | vm_object_t, cached_list); | |
226 | vm_object_cached++; | |
227 | vm_object_cache_unlock(); | |
228 | ||
229 | vm_object_deactivate_pages(object); | |
230 | vm_object_unlock(object); | |
231 | ||
232 | vm_object_cache_trim(); | |
233 | return; | |
234 | } | |
235 | ||
236 | /* | |
237 | * Make sure no one can look us up now. | |
238 | */ | |
239 | vm_object_remove(object->pager); | |
240 | vm_object_cache_unlock(); | |
241 | ||
242 | temp = object->shadow; | |
243 | vm_object_terminate(object); | |
244 | /* unlocks and deallocates object */ | |
245 | object = temp; | |
246 | } | |
247 | } | |
248 | ||
249 | ||
250 | /* | |
251 | * vm_object_terminate actually destroys the specified object, freeing | |
252 | * up all previously used resources. | |
253 | * | |
254 | * The object must be locked. | |
255 | */ | |
256 | void vm_object_terminate(object) | |
257 | register vm_object_t object; | |
258 | { | |
259 | register vm_page_t p; | |
260 | vm_object_t shadow_object; | |
261 | ||
262 | /* | |
263 | * Detach the object from its shadow if we are the shadow's | |
264 | * copy. | |
265 | */ | |
ffe0d082 | 266 | if ((shadow_object = object->shadow) != NULL) { |
175f072e KM |
267 | vm_object_lock(shadow_object); |
268 | if (shadow_object->copy == object) | |
ffe0d082 | 269 | shadow_object->copy = NULL; |
175f072e | 270 | #if 0 |
ffe0d082 | 271 | else if (shadow_object->copy != NULL) |
175f072e KM |
272 | panic("vm_object_terminate: copy/shadow inconsistency"); |
273 | #endif | |
274 | vm_object_unlock(shadow_object); | |
275 | } | |
276 | ||
277 | /* | |
888963d8 | 278 | * Wait until the pageout daemon is through with the object. |
175f072e | 279 | */ |
888963d8 | 280 | while (object->paging_in_progress) { |
90314fa1 | 281 | vm_object_sleep((int)object, object, FALSE); |
175f072e KM |
282 | vm_object_lock(object); |
283 | } | |
284 | ||
175f072e | 285 | /* |
888963d8 MH |
286 | * If not an internal object clean all the pages, removing them |
287 | * from paging queues as we go. | |
175f072e | 288 | */ |
888963d8 MH |
289 | if ((object->flags & OBJ_INTERNAL) == 0) { |
290 | vm_object_page_clean(object, 0, 0, TRUE); | |
291 | vm_object_unlock(object); | |
175f072e | 292 | } |
175f072e KM |
293 | |
294 | /* | |
888963d8 MH |
295 | * Now free the pages. |
296 | * For internal objects, this also removes them from paging queues. | |
175f072e | 297 | */ |
175f072e KM |
298 | while (!queue_empty(&object->memq)) { |
299 | p = (vm_page_t) queue_first(&object->memq); | |
175f072e | 300 | VM_PAGE_CHECK(p); |
175f072e KM |
301 | vm_page_lock_queues(); |
302 | vm_page_free(p); | |
303 | vm_page_unlock_queues(); | |
304 | } | |
888963d8 MH |
305 | if ((object->flags & OBJ_INTERNAL) == 0) |
306 | vm_object_unlock(object); | |
175f072e KM |
307 | |
308 | /* | |
888963d8 | 309 | * Let the pager know object is dead. |
175f072e | 310 | */ |
ffe0d082 | 311 | if (object->pager != NULL) |
175f072e KM |
312 | vm_pager_deallocate(object->pager); |
313 | ||
175f072e KM |
314 | simple_lock(&vm_object_list_lock); |
315 | queue_remove(&vm_object_list, object, vm_object_t, object_list); | |
316 | vm_object_count--; | |
317 | simple_unlock(&vm_object_list_lock); | |
318 | ||
319 | /* | |
888963d8 | 320 | * Free the space for the object. |
175f072e | 321 | */ |
175f072e KM |
322 | free((caddr_t)object, M_VMOBJ); |
323 | } | |
324 | ||
325 | /* | |
326 | * vm_object_page_clean | |
327 | * | |
328 | * Clean all dirty pages in the specified range of object. | |
888963d8 MH |
329 | * If dequeue is TRUE, pages are removed from any paging queue |
330 | * they were on, otherwise they are left on whatever queue they | |
331 | * were on before the cleaning operation began. | |
175f072e KM |
332 | * |
333 | * Odd semantics: if start == end, we clean everything. | |
334 | * | |
335 | * The object must be locked. | |
336 | */ | |
888963d8 | 337 | vm_object_page_clean(object, start, end, dequeue) |
175f072e KM |
338 | register vm_object_t object; |
339 | register vm_offset_t start; | |
340 | register vm_offset_t end; | |
888963d8 | 341 | boolean_t dequeue; |
175f072e KM |
342 | { |
343 | register vm_page_t p; | |
888963d8 | 344 | int onqueue; |
175f072e | 345 | |
ffe0d082 | 346 | if (object->pager == NULL) |
175f072e KM |
347 | return; |
348 | ||
349 | again: | |
888963d8 MH |
350 | /* |
351 | * Wait until the pageout daemon is through with the object. | |
352 | */ | |
353 | while (object->paging_in_progress) { | |
354 | vm_object_sleep((int)object, object, FALSE); | |
355 | vm_object_lock(object); | |
356 | } | |
357 | /* | |
358 | * Loop through the object page list cleaning as necessary. | |
359 | */ | |
175f072e KM |
360 | p = (vm_page_t) queue_first(&object->memq); |
361 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
362 | if (start == end || | |
363 | p->offset >= start && p->offset < end) { | |
364 | if (p->clean && pmap_is_modified(VM_PAGE_TO_PHYS(p))) | |
365 | p->clean = FALSE; | |
888963d8 MH |
366 | /* |
367 | * Remove the page from any paging queue. | |
368 | * This needs to be done if either we have been | |
369 | * explicitly asked to do so or it is about to | |
370 | * be cleaned (see comment below). | |
371 | */ | |
372 | if (dequeue || !p->clean) { | |
373 | vm_page_lock_queues(); | |
374 | if (p->active) { | |
375 | queue_remove(&vm_page_queue_active, | |
376 | p, vm_page_t, pageq); | |
377 | p->active = FALSE; | |
378 | cnt.v_active_count--; | |
379 | onqueue = 1; | |
380 | } else if (p->inactive) { | |
381 | queue_remove(&vm_page_queue_inactive, | |
382 | p, vm_page_t, pageq); | |
383 | p->inactive = FALSE; | |
384 | cnt.v_inactive_count--; | |
385 | onqueue = -1; | |
386 | } else | |
387 | onqueue = 0; | |
388 | vm_page_unlock_queues(); | |
389 | } | |
390 | /* | |
391 | * To ensure the state of the page doesn't change | |
392 | * during the clean operation we do two things. | |
393 | * First we set the busy bit and invalidate all | |
394 | * mappings to ensure that thread accesses to the | |
395 | * page block (in vm_fault). Second, we remove | |
396 | * the page from any paging queue to foil the | |
397 | * pageout daemon (vm_pageout_scan). | |
398 | */ | |
ae1e5b95 | 399 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); |
175f072e KM |
400 | if (!p->clean) { |
401 | p->busy = TRUE; | |
402 | object->paging_in_progress++; | |
403 | vm_object_unlock(object); | |
404 | (void) vm_pager_put(object->pager, p, TRUE); | |
405 | vm_object_lock(object); | |
406 | object->paging_in_progress--; | |
888963d8 MH |
407 | if (!dequeue && onqueue) { |
408 | vm_page_lock_queues(); | |
409 | if (onqueue > 0) | |
410 | vm_page_activate(p); | |
411 | else | |
412 | vm_page_deactivate(p); | |
413 | vm_page_unlock_queues(); | |
414 | } | |
175f072e KM |
415 | p->busy = FALSE; |
416 | PAGE_WAKEUP(p); | |
417 | goto again; | |
418 | } | |
419 | } | |
420 | p = (vm_page_t) queue_next(&p->listq); | |
421 | } | |
422 | } | |
423 | ||
424 | /* | |
425 | * vm_object_deactivate_pages | |
426 | * | |
427 | * Deactivate all pages in the specified object. (Keep its pages | |
428 | * in memory even though it is no longer referenced.) | |
429 | * | |
430 | * The object must be locked. | |
431 | */ | |
432 | vm_object_deactivate_pages(object) | |
433 | register vm_object_t object; | |
434 | { | |
435 | register vm_page_t p, next; | |
436 | ||
437 | p = (vm_page_t) queue_first(&object->memq); | |
438 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
439 | next = (vm_page_t) queue_next(&p->listq); | |
440 | vm_page_lock_queues(); | |
441 | vm_page_deactivate(p); | |
442 | vm_page_unlock_queues(); | |
443 | p = next; | |
444 | } | |
445 | } | |
446 | ||
447 | /* | |
448 | * Trim the object cache to size. | |
449 | */ | |
450 | vm_object_cache_trim() | |
451 | { | |
452 | register vm_object_t object; | |
453 | ||
454 | vm_object_cache_lock(); | |
455 | while (vm_object_cached > vm_cache_max) { | |
456 | object = (vm_object_t) queue_first(&vm_object_cached_list); | |
457 | vm_object_cache_unlock(); | |
458 | ||
459 | if (object != vm_object_lookup(object->pager)) | |
460 | panic("vm_object_deactivate: I'm sooo confused."); | |
461 | ||
462 | pager_cache(object, FALSE); | |
463 | ||
464 | vm_object_cache_lock(); | |
465 | } | |
466 | vm_object_cache_unlock(); | |
467 | } | |
468 | ||
469 | ||
470 | /* | |
471 | * vm_object_shutdown() | |
472 | * | |
473 | * Shut down the object system. Unfortunately, while we | |
474 | * may be trying to do this, init is happily waiting for | |
475 | * processes to exit, and therefore will be causing some objects | |
476 | * to be deallocated. To handle this, we gain a fake reference | |
477 | * to all objects we release paging areas for. This will prevent | |
478 | * a duplicate deallocation. This routine is probably full of | |
479 | * race conditions! | |
480 | */ | |
481 | ||
482 | void vm_object_shutdown() | |
483 | { | |
484 | register vm_object_t object; | |
485 | ||
486 | /* | |
487 | * Clean up the object cache *before* we screw up the reference | |
488 | * counts on all of the objects. | |
489 | */ | |
490 | ||
491 | vm_object_cache_clear(); | |
492 | ||
493 | printf("free paging spaces: "); | |
494 | ||
495 | /* | |
496 | * First we gain a reference to each object so that | |
497 | * no one else will deallocate them. | |
498 | */ | |
499 | ||
500 | simple_lock(&vm_object_list_lock); | |
501 | object = (vm_object_t) queue_first(&vm_object_list); | |
502 | while (!queue_end(&vm_object_list, (queue_entry_t) object)) { | |
503 | vm_object_reference(object); | |
504 | object = (vm_object_t) queue_next(&object->object_list); | |
505 | } | |
506 | simple_unlock(&vm_object_list_lock); | |
507 | ||
508 | /* | |
509 | * Now we deallocate all the paging areas. We don't need | |
510 | * to lock anything because we've reduced to a single | |
511 | * processor while shutting down. This also assumes that | |
512 | * no new objects are being created. | |
513 | */ | |
514 | ||
515 | object = (vm_object_t) queue_first(&vm_object_list); | |
516 | while (!queue_end(&vm_object_list, (queue_entry_t) object)) { | |
ffe0d082 | 517 | if (object->pager != NULL) |
175f072e KM |
518 | vm_pager_deallocate(object->pager); |
519 | object = (vm_object_t) queue_next(&object->object_list); | |
520 | printf("."); | |
521 | } | |
522 | printf("done.\n"); | |
523 | } | |
524 | ||
525 | /* | |
526 | * vm_object_pmap_copy: | |
527 | * | |
528 | * Makes all physical pages in the specified | |
529 | * object range copy-on-write. No writeable | |
530 | * references to these pages should remain. | |
531 | * | |
532 | * The object must *not* be locked. | |
533 | */ | |
534 | void vm_object_pmap_copy(object, start, end) | |
535 | register vm_object_t object; | |
536 | register vm_offset_t start; | |
537 | register vm_offset_t end; | |
538 | { | |
539 | register vm_page_t p; | |
540 | ||
ffe0d082 | 541 | if (object == NULL) |
175f072e KM |
542 | return; |
543 | ||
544 | vm_object_lock(object); | |
545 | p = (vm_page_t) queue_first(&object->memq); | |
546 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
547 | if ((start <= p->offset) && (p->offset < end)) { | |
ae1e5b95 MH |
548 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_READ); |
549 | p->copy_on_write = TRUE; | |
175f072e KM |
550 | } |
551 | p = (vm_page_t) queue_next(&p->listq); | |
552 | } | |
553 | vm_object_unlock(object); | |
554 | } | |
555 | ||
556 | /* | |
557 | * vm_object_pmap_remove: | |
558 | * | |
559 | * Removes all physical pages in the specified | |
560 | * object range from all physical maps. | |
561 | * | |
562 | * The object must *not* be locked. | |
563 | */ | |
564 | void vm_object_pmap_remove(object, start, end) | |
565 | register vm_object_t object; | |
566 | register vm_offset_t start; | |
567 | register vm_offset_t end; | |
568 | { | |
569 | register vm_page_t p; | |
570 | ||
ffe0d082 | 571 | if (object == NULL) |
175f072e KM |
572 | return; |
573 | ||
574 | vm_object_lock(object); | |
575 | p = (vm_page_t) queue_first(&object->memq); | |
576 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
ae1e5b95 MH |
577 | if ((start <= p->offset) && (p->offset < end)) |
578 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); | |
175f072e KM |
579 | p = (vm_page_t) queue_next(&p->listq); |
580 | } | |
581 | vm_object_unlock(object); | |
582 | } | |
583 | ||
584 | /* | |
585 | * vm_object_copy: | |
586 | * | |
587 | * Create a new object which is a copy of an existing | |
588 | * object, and mark all of the pages in the existing | |
589 | * object 'copy-on-write'. The new object has one reference. | |
590 | * Returns the new object. | |
591 | * | |
592 | * May defer the copy until later if the object is not backed | |
593 | * up by a non-default pager. | |
594 | */ | |
595 | void vm_object_copy(src_object, src_offset, size, | |
596 | dst_object, dst_offset, src_needs_copy) | |
597 | register vm_object_t src_object; | |
598 | vm_offset_t src_offset; | |
599 | vm_size_t size; | |
600 | vm_object_t *dst_object; /* OUT */ | |
601 | vm_offset_t *dst_offset; /* OUT */ | |
602 | boolean_t *src_needs_copy; /* OUT */ | |
603 | { | |
604 | register vm_object_t new_copy; | |
605 | register vm_object_t old_copy; | |
606 | vm_offset_t new_start, new_end; | |
607 | ||
608 | register vm_page_t p; | |
609 | ||
ffe0d082 | 610 | if (src_object == NULL) { |
175f072e KM |
611 | /* |
612 | * Nothing to copy | |
613 | */ | |
ffe0d082 | 614 | *dst_object = NULL; |
175f072e KM |
615 | *dst_offset = 0; |
616 | *src_needs_copy = FALSE; | |
617 | return; | |
618 | } | |
619 | ||
620 | /* | |
621 | * If the object's pager is null_pager or the | |
622 | * default pager, we don't have to make a copy | |
623 | * of it. Instead, we set the needs copy flag and | |
624 | * make a shadow later. | |
625 | */ | |
626 | ||
627 | vm_object_lock(src_object); | |
ffe0d082 | 628 | if (src_object->pager == NULL || |
d4ab8fb9 | 629 | (src_object->flags & OBJ_INTERNAL)) { |
175f072e KM |
630 | |
631 | /* | |
632 | * Make another reference to the object | |
633 | */ | |
634 | src_object->ref_count++; | |
635 | ||
636 | /* | |
637 | * Mark all of the pages copy-on-write. | |
638 | */ | |
639 | for (p = (vm_page_t) queue_first(&src_object->memq); | |
640 | !queue_end(&src_object->memq, (queue_entry_t)p); | |
641 | p = (vm_page_t) queue_next(&p->listq)) { | |
642 | if (src_offset <= p->offset && | |
643 | p->offset < src_offset + size) | |
644 | p->copy_on_write = TRUE; | |
645 | } | |
646 | vm_object_unlock(src_object); | |
647 | ||
648 | *dst_object = src_object; | |
649 | *dst_offset = src_offset; | |
650 | ||
651 | /* | |
652 | * Must make a shadow when write is desired | |
653 | */ | |
654 | *src_needs_copy = TRUE; | |
655 | return; | |
656 | } | |
657 | ||
658 | /* | |
659 | * Try to collapse the object before copying it. | |
660 | */ | |
661 | vm_object_collapse(src_object); | |
662 | ||
663 | /* | |
664 | * If the object has a pager, the pager wants to | |
665 | * see all of the changes. We need a copy-object | |
666 | * for the changed pages. | |
667 | * | |
668 | * If there is a copy-object, and it is empty, | |
669 | * no changes have been made to the object since the | |
670 | * copy-object was made. We can use the same copy- | |
671 | * object. | |
672 | */ | |
673 | ||
674 | Retry1: | |
675 | old_copy = src_object->copy; | |
ffe0d082 | 676 | if (old_copy != NULL) { |
175f072e KM |
677 | /* |
678 | * Try to get the locks (out of order) | |
679 | */ | |
680 | if (!vm_object_lock_try(old_copy)) { | |
681 | vm_object_unlock(src_object); | |
682 | ||
683 | /* should spin a bit here... */ | |
684 | vm_object_lock(src_object); | |
685 | goto Retry1; | |
686 | } | |
687 | ||
688 | if (old_copy->resident_page_count == 0 && | |
ffe0d082 | 689 | old_copy->pager == NULL) { |
175f072e KM |
690 | /* |
691 | * Return another reference to | |
692 | * the existing copy-object. | |
693 | */ | |
694 | old_copy->ref_count++; | |
695 | vm_object_unlock(old_copy); | |
696 | vm_object_unlock(src_object); | |
697 | *dst_object = old_copy; | |
698 | *dst_offset = src_offset; | |
699 | *src_needs_copy = FALSE; | |
700 | return; | |
701 | } | |
702 | vm_object_unlock(old_copy); | |
703 | } | |
704 | vm_object_unlock(src_object); | |
705 | ||
706 | /* | |
707 | * If the object has a pager, the pager wants | |
708 | * to see all of the changes. We must make | |
709 | * a copy-object and put the changed pages there. | |
710 | * | |
711 | * The copy-object is always made large enough to | |
712 | * completely shadow the original object, since | |
713 | * it may have several users who want to shadow | |
714 | * the original object at different points. | |
715 | */ | |
716 | ||
717 | new_copy = vm_object_allocate(src_object->size); | |
718 | ||
719 | Retry2: | |
720 | vm_object_lock(src_object); | |
721 | /* | |
722 | * Copy object may have changed while we were unlocked | |
723 | */ | |
724 | old_copy = src_object->copy; | |
ffe0d082 | 725 | if (old_copy != NULL) { |
175f072e KM |
726 | /* |
727 | * Try to get the locks (out of order) | |
728 | */ | |
729 | if (!vm_object_lock_try(old_copy)) { | |
730 | vm_object_unlock(src_object); | |
731 | goto Retry2; | |
732 | } | |
733 | ||
734 | /* | |
735 | * Consistency check | |
736 | */ | |
737 | if (old_copy->shadow != src_object || | |
738 | old_copy->shadow_offset != (vm_offset_t) 0) | |
739 | panic("vm_object_copy: copy/shadow inconsistency"); | |
740 | ||
741 | /* | |
742 | * Make the old copy-object shadow the new one. | |
743 | * It will receive no more pages from the original | |
744 | * object. | |
745 | */ | |
746 | ||
747 | src_object->ref_count--; /* remove ref. from old_copy */ | |
748 | old_copy->shadow = new_copy; | |
749 | new_copy->ref_count++; /* locking not needed - we | |
750 | have the only pointer */ | |
751 | vm_object_unlock(old_copy); /* done with old_copy */ | |
752 | } | |
753 | ||
754 | new_start = (vm_offset_t) 0; /* always shadow original at 0 */ | |
755 | new_end = (vm_offset_t) new_copy->size; /* for the whole object */ | |
756 | ||
757 | /* | |
758 | * Point the new copy at the existing object. | |
759 | */ | |
760 | ||
761 | new_copy->shadow = src_object; | |
762 | new_copy->shadow_offset = new_start; | |
763 | src_object->ref_count++; | |
764 | src_object->copy = new_copy; | |
765 | ||
766 | /* | |
767 | * Mark all the affected pages of the existing object | |
768 | * copy-on-write. | |
769 | */ | |
770 | p = (vm_page_t) queue_first(&src_object->memq); | |
771 | while (!queue_end(&src_object->memq, (queue_entry_t) p)) { | |
ae1e5b95 | 772 | if ((new_start <= p->offset) && (p->offset < new_end)) |
175f072e | 773 | p->copy_on_write = TRUE; |
175f072e KM |
774 | p = (vm_page_t) queue_next(&p->listq); |
775 | } | |
776 | ||
777 | vm_object_unlock(src_object); | |
778 | ||
779 | *dst_object = new_copy; | |
780 | *dst_offset = src_offset - new_start; | |
781 | *src_needs_copy = FALSE; | |
782 | } | |
783 | ||
784 | /* | |
785 | * vm_object_shadow: | |
786 | * | |
787 | * Create a new object which is backed by the | |
788 | * specified existing object range. The source | |
789 | * object reference is deallocated. | |
790 | * | |
791 | * The new object and offset into that object | |
792 | * are returned in the source parameters. | |
793 | */ | |
794 | ||
795 | void vm_object_shadow(object, offset, length) | |
796 | vm_object_t *object; /* IN/OUT */ | |
797 | vm_offset_t *offset; /* IN/OUT */ | |
798 | vm_size_t length; | |
799 | { | |
800 | register vm_object_t source; | |
801 | register vm_object_t result; | |
802 | ||
803 | source = *object; | |
804 | ||
805 | /* | |
806 | * Allocate a new object with the given length | |
807 | */ | |
808 | ||
ffe0d082 | 809 | if ((result = vm_object_allocate(length)) == NULL) |
175f072e KM |
810 | panic("vm_object_shadow: no object for shadowing"); |
811 | ||
812 | /* | |
813 | * The new object shadows the source object, adding | |
814 | * a reference to it. Our caller changes his reference | |
815 | * to point to the new object, removing a reference to | |
816 | * the source object. Net result: no change of reference | |
817 | * count. | |
818 | */ | |
819 | result->shadow = source; | |
820 | ||
821 | /* | |
822 | * Store the offset into the source object, | |
823 | * and fix up the offset into the new object. | |
824 | */ | |
825 | ||
826 | result->shadow_offset = *offset; | |
827 | ||
828 | /* | |
829 | * Return the new things | |
830 | */ | |
831 | ||
832 | *offset = 0; | |
833 | *object = result; | |
834 | } | |
835 | ||
836 | /* | |
837 | * Set the specified object's pager to the specified pager. | |
838 | */ | |
839 | ||
840 | void vm_object_setpager(object, pager, paging_offset, | |
841 | read_only) | |
842 | vm_object_t object; | |
843 | vm_pager_t pager; | |
844 | vm_offset_t paging_offset; | |
845 | boolean_t read_only; | |
846 | { | |
847 | #ifdef lint | |
848 | read_only++; /* No longer used */ | |
849 | #endif lint | |
850 | ||
851 | vm_object_lock(object); /* XXX ? */ | |
852 | object->pager = pager; | |
853 | object->paging_offset = paging_offset; | |
854 | vm_object_unlock(object); /* XXX ? */ | |
855 | } | |
856 | ||
857 | /* | |
858 | * vm_object_hash hashes the pager/id pair. | |
859 | */ | |
860 | ||
861 | #define vm_object_hash(pager) \ | |
862 | (((unsigned)pager)%VM_OBJECT_HASH_COUNT) | |
863 | ||
864 | /* | |
865 | * vm_object_lookup looks in the object cache for an object with the | |
866 | * specified pager and paging id. | |
867 | */ | |
868 | ||
869 | vm_object_t vm_object_lookup(pager) | |
870 | vm_pager_t pager; | |
871 | { | |
872 | register queue_t bucket; | |
873 | register vm_object_hash_entry_t entry; | |
874 | vm_object_t object; | |
875 | ||
876 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
877 | ||
878 | vm_object_cache_lock(); | |
879 | ||
880 | entry = (vm_object_hash_entry_t) queue_first(bucket); | |
881 | while (!queue_end(bucket, (queue_entry_t) entry)) { | |
882 | object = entry->object; | |
883 | if (object->pager == pager) { | |
884 | vm_object_lock(object); | |
885 | if (object->ref_count == 0) { | |
886 | queue_remove(&vm_object_cached_list, object, | |
887 | vm_object_t, cached_list); | |
888 | vm_object_cached--; | |
889 | } | |
890 | object->ref_count++; | |
891 | vm_object_unlock(object); | |
892 | vm_object_cache_unlock(); | |
893 | return(object); | |
894 | } | |
895 | entry = (vm_object_hash_entry_t) queue_next(&entry->hash_links); | |
896 | } | |
897 | ||
898 | vm_object_cache_unlock(); | |
ffe0d082 | 899 | return(NULL); |
175f072e KM |
900 | } |
901 | ||
902 | /* | |
903 | * vm_object_enter enters the specified object/pager/id into | |
904 | * the hash table. | |
905 | */ | |
906 | ||
907 | void vm_object_enter(object, pager) | |
908 | vm_object_t object; | |
909 | vm_pager_t pager; | |
910 | { | |
911 | register queue_t bucket; | |
912 | register vm_object_hash_entry_t entry; | |
913 | ||
914 | /* | |
915 | * We don't cache null objects, and we can't cache | |
916 | * objects with the null pager. | |
917 | */ | |
918 | ||
ffe0d082 | 919 | if (object == NULL) |
175f072e | 920 | return; |
ffe0d082 | 921 | if (pager == NULL) |
175f072e KM |
922 | return; |
923 | ||
924 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
925 | entry = (vm_object_hash_entry_t) | |
926 | malloc((u_long)sizeof *entry, M_VMOBJHASH, M_WAITOK); | |
927 | entry->object = object; | |
d4ab8fb9 | 928 | object->flags |= OBJ_CANPERSIST; |
175f072e KM |
929 | |
930 | vm_object_cache_lock(); | |
931 | queue_enter(bucket, entry, vm_object_hash_entry_t, hash_links); | |
932 | vm_object_cache_unlock(); | |
933 | } | |
934 | ||
935 | /* | |
936 | * vm_object_remove: | |
937 | * | |
938 | * Remove the pager from the hash table. | |
939 | * Note: This assumes that the object cache | |
940 | * is locked. XXX this should be fixed | |
941 | * by reorganizing vm_object_deallocate. | |
942 | */ | |
943 | vm_object_remove(pager) | |
944 | register vm_pager_t pager; | |
945 | { | |
946 | register queue_t bucket; | |
947 | register vm_object_hash_entry_t entry; | |
948 | register vm_object_t object; | |
949 | ||
950 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
951 | ||
952 | entry = (vm_object_hash_entry_t) queue_first(bucket); | |
953 | while (!queue_end(bucket, (queue_entry_t) entry)) { | |
954 | object = entry->object; | |
955 | if (object->pager == pager) { | |
956 | queue_remove(bucket, entry, vm_object_hash_entry_t, | |
957 | hash_links); | |
958 | free((caddr_t)entry, M_VMOBJHASH); | |
959 | break; | |
960 | } | |
961 | entry = (vm_object_hash_entry_t) queue_next(&entry->hash_links); | |
962 | } | |
963 | } | |
964 | ||
965 | /* | |
966 | * vm_object_cache_clear removes all objects from the cache. | |
967 | * | |
968 | */ | |
969 | ||
970 | void vm_object_cache_clear() | |
971 | { | |
972 | register vm_object_t object; | |
973 | ||
974 | /* | |
975 | * Remove each object in the cache by scanning down the | |
976 | * list of cached objects. | |
977 | */ | |
978 | vm_object_cache_lock(); | |
979 | while (!queue_empty(&vm_object_cached_list)) { | |
980 | object = (vm_object_t) queue_first(&vm_object_cached_list); | |
981 | vm_object_cache_unlock(); | |
982 | ||
983 | /* | |
984 | * Note: it is important that we use vm_object_lookup | |
985 | * to gain a reference, and not vm_object_reference, because | |
986 | * the logic for removing an object from the cache lies in | |
987 | * lookup. | |
988 | */ | |
989 | if (object != vm_object_lookup(object->pager)) | |
990 | panic("vm_object_cache_clear: I'm sooo confused."); | |
991 | pager_cache(object, FALSE); | |
992 | ||
993 | vm_object_cache_lock(); | |
994 | } | |
995 | vm_object_cache_unlock(); | |
996 | } | |
997 | ||
998 | boolean_t vm_object_collapse_allowed = TRUE; | |
999 | /* | |
1000 | * vm_object_collapse: | |
1001 | * | |
1002 | * Collapse an object with the object backing it. | |
1003 | * Pages in the backing object are moved into the | |
1004 | * parent, and the backing object is deallocated. | |
1005 | * | |
1006 | * Requires that the object be locked and the page | |
1007 | * queues be unlocked. | |
1008 | * | |
1009 | */ | |
1010 | void vm_object_collapse(object) | |
1011 | register vm_object_t object; | |
1012 | ||
1013 | { | |
1014 | register vm_object_t backing_object; | |
1015 | register vm_offset_t backing_offset; | |
1016 | register vm_size_t size; | |
1017 | register vm_offset_t new_offset; | |
1018 | register vm_page_t p, pp; | |
1019 | ||
1020 | if (!vm_object_collapse_allowed) | |
1021 | return; | |
1022 | ||
1023 | while (TRUE) { | |
1024 | /* | |
1025 | * Verify that the conditions are right for collapse: | |
1026 | * | |
1027 | * The object exists and no pages in it are currently | |
1028 | * being paged out (or have ever been paged out). | |
1029 | */ | |
ffe0d082 | 1030 | if (object == NULL || |
175f072e | 1031 | object->paging_in_progress != 0 || |
ffe0d082 | 1032 | object->pager != NULL) |
175f072e KM |
1033 | return; |
1034 | ||
1035 | /* | |
1036 | * There is a backing object, and | |
1037 | */ | |
1038 | ||
ffe0d082 | 1039 | if ((backing_object = object->shadow) == NULL) |
175f072e KM |
1040 | return; |
1041 | ||
1042 | vm_object_lock(backing_object); | |
1043 | /* | |
1044 | * ... | |
1045 | * The backing object is not read_only, | |
1046 | * and no pages in the backing object are | |
1047 | * currently being paged out. | |
1048 | * The backing object is internal. | |
1049 | */ | |
1050 | ||
d4ab8fb9 | 1051 | if ((backing_object->flags & OBJ_INTERNAL) == 0 || |
175f072e KM |
1052 | backing_object->paging_in_progress != 0) { |
1053 | vm_object_unlock(backing_object); | |
1054 | return; | |
1055 | } | |
1056 | ||
1057 | /* | |
1058 | * The backing object can't be a copy-object: | |
1059 | * the shadow_offset for the copy-object must stay | |
1060 | * as 0. Furthermore (for the 'we have all the | |
1061 | * pages' case), if we bypass backing_object and | |
1062 | * just shadow the next object in the chain, old | |
1063 | * pages from that object would then have to be copied | |
1064 | * BOTH into the (former) backing_object and into the | |
1065 | * parent object. | |
1066 | */ | |
ffe0d082 MK |
1067 | if (backing_object->shadow != NULL && |
1068 | backing_object->shadow->copy != NULL) { | |
175f072e KM |
1069 | vm_object_unlock(backing_object); |
1070 | return; | |
1071 | } | |
1072 | ||
1073 | /* | |
1074 | * We know that we can either collapse the backing | |
1075 | * object (if the parent is the only reference to | |
1076 | * it) or (perhaps) remove the parent's reference | |
1077 | * to it. | |
1078 | */ | |
1079 | ||
1080 | backing_offset = object->shadow_offset; | |
1081 | size = object->size; | |
1082 | ||
1083 | /* | |
1084 | * If there is exactly one reference to the backing | |
1085 | * object, we can collapse it into the parent. | |
1086 | */ | |
1087 | ||
1088 | if (backing_object->ref_count == 1) { | |
1089 | ||
1090 | /* | |
1091 | * We can collapse the backing object. | |
1092 | * | |
1093 | * Move all in-memory pages from backing_object | |
1094 | * to the parent. Pages that have been paged out | |
1095 | * will be overwritten by any of the parent's | |
1096 | * pages that shadow them. | |
1097 | */ | |
1098 | ||
1099 | while (!queue_empty(&backing_object->memq)) { | |
1100 | ||
1101 | p = (vm_page_t) | |
1102 | queue_first(&backing_object->memq); | |
1103 | ||
1104 | new_offset = (p->offset - backing_offset); | |
1105 | ||
1106 | /* | |
1107 | * If the parent has a page here, or if | |
1108 | * this page falls outside the parent, | |
1109 | * dispose of it. | |
1110 | * | |
1111 | * Otherwise, move it as planned. | |
1112 | */ | |
1113 | ||
1114 | if (p->offset < backing_offset || | |
1115 | new_offset >= size) { | |
1116 | vm_page_lock_queues(); | |
1117 | vm_page_free(p); | |
1118 | vm_page_unlock_queues(); | |
1119 | } else { | |
1120 | pp = vm_page_lookup(object, new_offset); | |
ffe0d082 | 1121 | if (pp != NULL && !pp->fake) { |
175f072e KM |
1122 | vm_page_lock_queues(); |
1123 | vm_page_free(p); | |
1124 | vm_page_unlock_queues(); | |
1125 | } | |
1126 | else { | |
1127 | if (pp) { | |
1128 | /* may be someone waiting for it */ | |
1129 | PAGE_WAKEUP(pp); | |
1130 | vm_page_lock_queues(); | |
1131 | vm_page_free(pp); | |
1132 | vm_page_unlock_queues(); | |
1133 | } | |
1134 | vm_page_rename(p, object, new_offset); | |
1135 | } | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | /* | |
1140 | * Move the pager from backing_object to object. | |
1141 | * | |
1142 | * XXX We're only using part of the paging space | |
1143 | * for keeps now... we ought to discard the | |
1144 | * unused portion. | |
1145 | */ | |
1146 | ||
1147 | object->pager = backing_object->pager; | |
1148 | object->paging_offset += backing_offset; | |
1149 | ||
ffe0d082 | 1150 | backing_object->pager = NULL; |
175f072e KM |
1151 | |
1152 | /* | |
1153 | * Object now shadows whatever backing_object did. | |
1154 | * Note that the reference to backing_object->shadow | |
1155 | * moves from within backing_object to within object. | |
1156 | */ | |
1157 | ||
1158 | object->shadow = backing_object->shadow; | |
1159 | object->shadow_offset += backing_object->shadow_offset; | |
ffe0d082 MK |
1160 | if (object->shadow != NULL && |
1161 | object->shadow->copy != NULL) { | |
175f072e KM |
1162 | panic("vm_object_collapse: we collapsed a copy-object!"); |
1163 | } | |
1164 | /* | |
1165 | * Discard backing_object. | |
1166 | * | |
1167 | * Since the backing object has no pages, no | |
1168 | * pager left, and no object references within it, | |
1169 | * all that is necessary is to dispose of it. | |
1170 | */ | |
1171 | ||
1172 | vm_object_unlock(backing_object); | |
1173 | ||
1174 | simple_lock(&vm_object_list_lock); | |
1175 | queue_remove(&vm_object_list, backing_object, | |
1176 | vm_object_t, object_list); | |
1177 | vm_object_count--; | |
1178 | simple_unlock(&vm_object_list_lock); | |
1179 | ||
1180 | free((caddr_t)backing_object, M_VMOBJ); | |
1181 | ||
1182 | object_collapses++; | |
1183 | } | |
1184 | else { | |
1185 | /* | |
1186 | * If all of the pages in the backing object are | |
1187 | * shadowed by the parent object, the parent | |
1188 | * object no longer has to shadow the backing | |
1189 | * object; it can shadow the next one in the | |
1190 | * chain. | |
1191 | * | |
1192 | * The backing object must not be paged out - we'd | |
1193 | * have to check all of the paged-out pages, as | |
1194 | * well. | |
1195 | */ | |
1196 | ||
ffe0d082 | 1197 | if (backing_object->pager != NULL) { |
175f072e KM |
1198 | vm_object_unlock(backing_object); |
1199 | return; | |
1200 | } | |
1201 | ||
1202 | /* | |
1203 | * Should have a check for a 'small' number | |
1204 | * of pages here. | |
1205 | */ | |
1206 | ||
1207 | p = (vm_page_t) queue_first(&backing_object->memq); | |
1208 | while (!queue_end(&backing_object->memq, | |
1209 | (queue_entry_t) p)) { | |
1210 | ||
1211 | new_offset = (p->offset - backing_offset); | |
1212 | ||
1213 | /* | |
1214 | * If the parent has a page here, or if | |
1215 | * this page falls outside the parent, | |
1216 | * keep going. | |
1217 | * | |
1218 | * Otherwise, the backing_object must be | |
1219 | * left in the chain. | |
1220 | */ | |
1221 | ||
1222 | if (p->offset >= backing_offset && | |
1223 | new_offset <= size && | |
1224 | ((pp = vm_page_lookup(object, new_offset)) | |
ffe0d082 | 1225 | == NULL || |
175f072e KM |
1226 | pp->fake)) { |
1227 | /* | |
1228 | * Page still needed. | |
1229 | * Can't go any further. | |
1230 | */ | |
1231 | vm_object_unlock(backing_object); | |
1232 | return; | |
1233 | } | |
1234 | p = (vm_page_t) queue_next(&p->listq); | |
1235 | } | |
1236 | ||
1237 | /* | |
1238 | * Make the parent shadow the next object | |
1239 | * in the chain. Deallocating backing_object | |
1240 | * will not remove it, since its reference | |
1241 | * count is at least 2. | |
1242 | */ | |
1243 | ||
1244 | vm_object_reference(object->shadow = backing_object->shadow); | |
1245 | object->shadow_offset += backing_object->shadow_offset; | |
1246 | ||
1247 | /* Drop the reference count on backing_object. | |
1248 | * Since its ref_count was at least 2, it | |
1249 | * will not vanish; so we don't need to call | |
1250 | * vm_object_deallocate. | |
1251 | */ | |
1252 | backing_object->ref_count--; | |
1253 | vm_object_unlock(backing_object); | |
1254 | ||
1255 | object_bypasses ++; | |
1256 | ||
1257 | } | |
1258 | ||
1259 | /* | |
1260 | * Try again with this object's new backing object. | |
1261 | */ | |
1262 | } | |
1263 | } | |
1264 | ||
1265 | /* | |
1266 | * vm_object_page_remove: [internal] | |
1267 | * | |
1268 | * Removes all physical pages in the specified | |
1269 | * object range from the object's list of pages. | |
1270 | * | |
1271 | * The object must be locked. | |
1272 | */ | |
1273 | void vm_object_page_remove(object, start, end) | |
1274 | register vm_object_t object; | |
1275 | register vm_offset_t start; | |
1276 | register vm_offset_t end; | |
1277 | { | |
1278 | register vm_page_t p, next; | |
1279 | ||
ffe0d082 | 1280 | if (object == NULL) |
175f072e KM |
1281 | return; |
1282 | ||
1283 | p = (vm_page_t) queue_first(&object->memq); | |
1284 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
1285 | next = (vm_page_t) queue_next(&p->listq); | |
1286 | if ((start <= p->offset) && (p->offset < end)) { | |
ae1e5b95 | 1287 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); |
175f072e KM |
1288 | vm_page_lock_queues(); |
1289 | vm_page_free(p); | |
1290 | vm_page_unlock_queues(); | |
1291 | } | |
1292 | p = next; | |
1293 | } | |
1294 | } | |
1295 | ||
1296 | /* | |
1297 | * Routine: vm_object_coalesce | |
1298 | * Function: Coalesces two objects backing up adjoining | |
1299 | * regions of memory into a single object. | |
1300 | * | |
1301 | * returns TRUE if objects were combined. | |
1302 | * | |
1303 | * NOTE: Only works at the moment if the second object is NULL - | |
1304 | * if it's not, which object do we lock first? | |
1305 | * | |
1306 | * Parameters: | |
1307 | * prev_object First object to coalesce | |
1308 | * prev_offset Offset into prev_object | |
1309 | * next_object Second object into coalesce | |
1310 | * next_offset Offset into next_object | |
1311 | * | |
1312 | * prev_size Size of reference to prev_object | |
1313 | * next_size Size of reference to next_object | |
1314 | * | |
1315 | * Conditions: | |
1316 | * The object must *not* be locked. | |
1317 | */ | |
1318 | boolean_t vm_object_coalesce(prev_object, next_object, | |
1319 | prev_offset, next_offset, | |
1320 | prev_size, next_size) | |
1321 | ||
1322 | register vm_object_t prev_object; | |
1323 | vm_object_t next_object; | |
1324 | vm_offset_t prev_offset, next_offset; | |
1325 | vm_size_t prev_size, next_size; | |
1326 | { | |
1327 | vm_size_t newsize; | |
1328 | ||
1329 | #ifdef lint | |
1330 | next_offset++; | |
1331 | #endif lint | |
1332 | ||
ffe0d082 | 1333 | if (next_object != NULL) { |
175f072e KM |
1334 | return(FALSE); |
1335 | } | |
1336 | ||
ffe0d082 | 1337 | if (prev_object == NULL) { |
175f072e KM |
1338 | return(TRUE); |
1339 | } | |
1340 | ||
1341 | vm_object_lock(prev_object); | |
1342 | ||
1343 | /* | |
1344 | * Try to collapse the object first | |
1345 | */ | |
1346 | vm_object_collapse(prev_object); | |
1347 | ||
1348 | /* | |
1349 | * Can't coalesce if: | |
1350 | * . more than one reference | |
1351 | * . paged out | |
1352 | * . shadows another object | |
1353 | * . has a copy elsewhere | |
1354 | * (any of which mean that the pages not mapped to | |
1355 | * prev_entry may be in use anyway) | |
1356 | */ | |
1357 | ||
1358 | if (prev_object->ref_count > 1 || | |
ffe0d082 MK |
1359 | prev_object->pager != NULL || |
1360 | prev_object->shadow != NULL || | |
1361 | prev_object->copy != NULL) { | |
175f072e KM |
1362 | vm_object_unlock(prev_object); |
1363 | return(FALSE); | |
1364 | } | |
1365 | ||
1366 | /* | |
1367 | * Remove any pages that may still be in the object from | |
1368 | * a previous deallocation. | |
1369 | */ | |
1370 | ||
1371 | vm_object_page_remove(prev_object, | |
1372 | prev_offset + prev_size, | |
1373 | prev_offset + prev_size + next_size); | |
1374 | ||
1375 | /* | |
1376 | * Extend the object if necessary. | |
1377 | */ | |
1378 | newsize = prev_offset + prev_size + next_size; | |
1379 | if (newsize > prev_object->size) | |
1380 | prev_object->size = newsize; | |
1381 | ||
1382 | vm_object_unlock(prev_object); | |
1383 | return(TRUE); | |
1384 | } | |
1385 | ||
1386 | /* | |
1387 | * vm_object_print: [ debug ] | |
1388 | */ | |
1389 | void vm_object_print(object, full) | |
1390 | vm_object_t object; | |
1391 | boolean_t full; | |
1392 | { | |
1393 | register vm_page_t p; | |
1394 | extern indent; | |
1395 | ||
1396 | register int count; | |
1397 | ||
ffe0d082 | 1398 | if (object == NULL) |
175f072e KM |
1399 | return; |
1400 | ||
1401 | iprintf("Object 0x%x: size=0x%x, res=%d, ref=%d, ", | |
1402 | (int) object, (int) object->size, | |
1403 | object->resident_page_count, object->ref_count); | |
1404 | printf("pager=0x%x+0x%x, shadow=(0x%x)+0x%x\n", | |
1405 | (int) object->pager, (int) object->paging_offset, | |
1406 | (int) object->shadow, (int) object->shadow_offset); | |
1407 | printf("cache: next=0x%x, prev=0x%x\n", | |
1408 | object->cached_list.next, object->cached_list.prev); | |
1409 | ||
1410 | if (!full) | |
1411 | return; | |
1412 | ||
1413 | indent += 2; | |
1414 | count = 0; | |
1415 | p = (vm_page_t) queue_first(&object->memq); | |
1416 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
1417 | if (count == 0) | |
1418 | iprintf("memory:="); | |
1419 | else if (count == 6) { | |
1420 | printf("\n"); | |
1421 | iprintf(" ..."); | |
1422 | count = 0; | |
1423 | } else | |
1424 | printf(","); | |
1425 | count++; | |
1426 | ||
1427 | printf("(off=0x%x,page=0x%x)", p->offset, VM_PAGE_TO_PHYS(p)); | |
1428 | p = (vm_page_t) queue_next(&p->listq); | |
1429 | } | |
1430 | if (count != 0) | |
1431 | printf("\n"); | |
1432 | indent -= 2; | |
1433 | } |