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175f072e | 1 | /* |
ad0f93d2 KB |
2 | * Copyright (c) 1991, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
175f072e KM |
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 | * |
ad0f93d2 | 10 | * @(#)vm_object.c 8.1 (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 | ||
0b1533b1 KB |
43 | #include <sys/param.h> |
44 | #include <sys/systm.h> | |
45 | #include <sys/malloc.h> | |
ffe0d082 | 46 | |
0b1533b1 KB |
47 | #include <vm/vm.h> |
48 | #include <vm/vm_page.h> | |
175f072e KM |
49 | |
50 | /* | |
51 | * Virtual memory objects maintain the actual data | |
52 | * associated with allocated virtual memory. A given | |
53 | * page of memory exists within exactly one object. | |
54 | * | |
55 | * An object is only deallocated when all "references" | |
56 | * are given up. Only one "reference" to a given | |
57 | * region of an object should be writeable. | |
58 | * | |
59 | * Associated with each object is a list of all resident | |
60 | * memory pages belonging to that object; this list is | |
61 | * maintained by the "vm_page" module, and locked by the object's | |
62 | * lock. | |
63 | * | |
64 | * Each object also records a "pager" routine which is | |
65 | * used to retrieve (and store) pages to the proper backing | |
66 | * storage. In addition, objects may be backed by other | |
67 | * objects from which they were virtual-copied. | |
68 | * | |
69 | * The only items within the object structure which are | |
70 | * modified after time of creation are: | |
71 | * reference count locked by object's lock | |
72 | * pager routine locked by object's lock | |
73 | * | |
74 | */ | |
75 | ||
76 | struct vm_object kernel_object_store; | |
77 | struct vm_object kmem_object_store; | |
78 | ||
79 | #define VM_OBJECT_HASH_COUNT 157 | |
80 | ||
81 | int vm_cache_max = 100; /* can patch if necessary */ | |
82 | queue_head_t vm_object_hashtable[VM_OBJECT_HASH_COUNT]; | |
83 | ||
84 | long object_collapses = 0; | |
85 | long object_bypasses = 0; | |
86 | ||
0b1533b1 KB |
87 | static void _vm_object_allocate __P((vm_size_t, vm_object_t)); |
88 | ||
175f072e KM |
89 | /* |
90 | * vm_object_init: | |
91 | * | |
92 | * Initialize the VM objects module. | |
93 | */ | |
5d30158d MT |
94 | void vm_object_init(size) |
95 | vm_size_t size; | |
175f072e KM |
96 | { |
97 | register int i; | |
98 | ||
99 | queue_init(&vm_object_cached_list); | |
100 | queue_init(&vm_object_list); | |
101 | vm_object_count = 0; | |
102 | simple_lock_init(&vm_cache_lock); | |
103 | simple_lock_init(&vm_object_list_lock); | |
104 | ||
105 | for (i = 0; i < VM_OBJECT_HASH_COUNT; i++) | |
106 | queue_init(&vm_object_hashtable[i]); | |
107 | ||
108 | kernel_object = &kernel_object_store; | |
5d30158d | 109 | _vm_object_allocate(size, kernel_object); |
175f072e KM |
110 | |
111 | kmem_object = &kmem_object_store; | |
112 | _vm_object_allocate(VM_KMEM_SIZE + VM_MBUF_SIZE, kmem_object); | |
113 | } | |
114 | ||
115 | /* | |
116 | * vm_object_allocate: | |
117 | * | |
118 | * Returns a new object with the given size. | |
119 | */ | |
120 | ||
121 | vm_object_t vm_object_allocate(size) | |
122 | vm_size_t size; | |
123 | { | |
124 | register vm_object_t result; | |
125 | ||
126 | result = (vm_object_t) | |
127 | malloc((u_long)sizeof *result, M_VMOBJ, M_WAITOK); | |
128 | ||
129 | _vm_object_allocate(size, result); | |
130 | ||
131 | return(result); | |
132 | } | |
133 | ||
0b1533b1 | 134 | static void |
175f072e KM |
135 | _vm_object_allocate(size, object) |
136 | vm_size_t size; | |
137 | register vm_object_t object; | |
138 | { | |
139 | queue_init(&object->memq); | |
140 | vm_object_lock_init(object); | |
141 | object->ref_count = 1; | |
142 | object->resident_page_count = 0; | |
143 | object->size = size; | |
d4ab8fb9 | 144 | object->flags = OBJ_INTERNAL; /* vm_allocate_with_pager will reset */ |
175f072e | 145 | object->paging_in_progress = 0; |
ffe0d082 | 146 | object->copy = NULL; |
175f072e KM |
147 | |
148 | /* | |
149 | * Object starts out read-write, with no pager. | |
150 | */ | |
151 | ||
ffe0d082 | 152 | object->pager = NULL; |
175f072e | 153 | object->paging_offset = 0; |
ffe0d082 | 154 | object->shadow = NULL; |
175f072e KM |
155 | object->shadow_offset = (vm_offset_t) 0; |
156 | ||
157 | simple_lock(&vm_object_list_lock); | |
158 | queue_enter(&vm_object_list, object, vm_object_t, object_list); | |
159 | vm_object_count++; | |
160 | simple_unlock(&vm_object_list_lock); | |
161 | } | |
162 | ||
163 | /* | |
164 | * vm_object_reference: | |
165 | * | |
166 | * Gets another reference to the given object. | |
167 | */ | |
168 | void vm_object_reference(object) | |
169 | register vm_object_t object; | |
170 | { | |
ffe0d082 | 171 | if (object == NULL) |
175f072e KM |
172 | return; |
173 | ||
174 | vm_object_lock(object); | |
175 | object->ref_count++; | |
176 | vm_object_unlock(object); | |
177 | } | |
178 | ||
179 | /* | |
180 | * vm_object_deallocate: | |
181 | * | |
182 | * Release a reference to the specified object, | |
183 | * gained either through a vm_object_allocate | |
184 | * or a vm_object_reference call. When all references | |
185 | * are gone, storage associated with this object | |
186 | * may be relinquished. | |
187 | * | |
188 | * No object may be locked. | |
189 | */ | |
190 | void vm_object_deallocate(object) | |
191 | register vm_object_t object; | |
192 | { | |
193 | vm_object_t temp; | |
194 | ||
ffe0d082 | 195 | while (object != NULL) { |
175f072e KM |
196 | |
197 | /* | |
198 | * The cache holds a reference (uncounted) to | |
199 | * the object; we must lock it before removing | |
200 | * the object. | |
201 | */ | |
202 | ||
203 | vm_object_cache_lock(); | |
204 | ||
205 | /* | |
206 | * Lose the reference | |
207 | */ | |
208 | vm_object_lock(object); | |
209 | if (--(object->ref_count) != 0) { | |
210 | ||
211 | /* | |
212 | * If there are still references, then | |
213 | * we are done. | |
214 | */ | |
215 | vm_object_unlock(object); | |
216 | vm_object_cache_unlock(); | |
217 | return; | |
218 | } | |
219 | ||
220 | /* | |
221 | * See if this object can persist. If so, enter | |
222 | * it in the cache, then deactivate all of its | |
223 | * pages. | |
224 | */ | |
225 | ||
d4ab8fb9 | 226 | if (object->flags & OBJ_CANPERSIST) { |
175f072e KM |
227 | |
228 | queue_enter(&vm_object_cached_list, object, | |
229 | vm_object_t, cached_list); | |
230 | vm_object_cached++; | |
231 | vm_object_cache_unlock(); | |
232 | ||
233 | vm_object_deactivate_pages(object); | |
234 | vm_object_unlock(object); | |
235 | ||
236 | vm_object_cache_trim(); | |
237 | return; | |
238 | } | |
239 | ||
240 | /* | |
241 | * Make sure no one can look us up now. | |
242 | */ | |
243 | vm_object_remove(object->pager); | |
244 | vm_object_cache_unlock(); | |
245 | ||
246 | temp = object->shadow; | |
247 | vm_object_terminate(object); | |
248 | /* unlocks and deallocates object */ | |
249 | object = temp; | |
250 | } | |
251 | } | |
252 | ||
253 | ||
254 | /* | |
255 | * vm_object_terminate actually destroys the specified object, freeing | |
256 | * up all previously used resources. | |
257 | * | |
258 | * The object must be locked. | |
259 | */ | |
260 | void vm_object_terminate(object) | |
261 | register vm_object_t object; | |
262 | { | |
263 | register vm_page_t p; | |
264 | vm_object_t shadow_object; | |
265 | ||
266 | /* | |
267 | * Detach the object from its shadow if we are the shadow's | |
268 | * copy. | |
269 | */ | |
ffe0d082 | 270 | if ((shadow_object = object->shadow) != NULL) { |
175f072e KM |
271 | vm_object_lock(shadow_object); |
272 | if (shadow_object->copy == object) | |
ffe0d082 | 273 | shadow_object->copy = NULL; |
175f072e | 274 | #if 0 |
ffe0d082 | 275 | else if (shadow_object->copy != NULL) |
175f072e KM |
276 | panic("vm_object_terminate: copy/shadow inconsistency"); |
277 | #endif | |
278 | vm_object_unlock(shadow_object); | |
279 | } | |
280 | ||
281 | /* | |
888963d8 | 282 | * Wait until the pageout daemon is through with the object. |
175f072e | 283 | */ |
888963d8 | 284 | while (object->paging_in_progress) { |
90314fa1 | 285 | vm_object_sleep((int)object, object, FALSE); |
175f072e KM |
286 | vm_object_lock(object); |
287 | } | |
288 | ||
175f072e | 289 | /* |
888963d8 MH |
290 | * If not an internal object clean all the pages, removing them |
291 | * from paging queues as we go. | |
175f072e | 292 | */ |
888963d8 MH |
293 | if ((object->flags & OBJ_INTERNAL) == 0) { |
294 | vm_object_page_clean(object, 0, 0, TRUE); | |
295 | vm_object_unlock(object); | |
175f072e | 296 | } |
175f072e KM |
297 | |
298 | /* | |
888963d8 MH |
299 | * Now free the pages. |
300 | * For internal objects, this also removes them from paging queues. | |
175f072e | 301 | */ |
175f072e KM |
302 | while (!queue_empty(&object->memq)) { |
303 | p = (vm_page_t) queue_first(&object->memq); | |
175f072e | 304 | VM_PAGE_CHECK(p); |
175f072e KM |
305 | vm_page_lock_queues(); |
306 | vm_page_free(p); | |
307 | vm_page_unlock_queues(); | |
308 | } | |
888963d8 MH |
309 | if ((object->flags & OBJ_INTERNAL) == 0) |
310 | vm_object_unlock(object); | |
175f072e KM |
311 | |
312 | /* | |
888963d8 | 313 | * Let the pager know object is dead. |
175f072e | 314 | */ |
ffe0d082 | 315 | if (object->pager != NULL) |
175f072e KM |
316 | vm_pager_deallocate(object->pager); |
317 | ||
175f072e KM |
318 | simple_lock(&vm_object_list_lock); |
319 | queue_remove(&vm_object_list, object, vm_object_t, object_list); | |
320 | vm_object_count--; | |
321 | simple_unlock(&vm_object_list_lock); | |
322 | ||
323 | /* | |
888963d8 | 324 | * Free the space for the object. |
175f072e | 325 | */ |
175f072e KM |
326 | free((caddr_t)object, M_VMOBJ); |
327 | } | |
328 | ||
329 | /* | |
330 | * vm_object_page_clean | |
331 | * | |
332 | * Clean all dirty pages in the specified range of object. | |
25746cce | 333 | * If de_queue is TRUE, pages are removed from any paging queue |
888963d8 MH |
334 | * they were on, otherwise they are left on whatever queue they |
335 | * were on before the cleaning operation began. | |
175f072e KM |
336 | * |
337 | * Odd semantics: if start == end, we clean everything. | |
338 | * | |
339 | * The object must be locked. | |
340 | */ | |
0b1533b1 | 341 | void |
25746cce | 342 | vm_object_page_clean(object, start, end, de_queue) |
175f072e KM |
343 | register vm_object_t object; |
344 | register vm_offset_t start; | |
345 | register vm_offset_t end; | |
25746cce | 346 | boolean_t de_queue; |
175f072e KM |
347 | { |
348 | register vm_page_t p; | |
888963d8 | 349 | int onqueue; |
175f072e | 350 | |
ffe0d082 | 351 | if (object->pager == NULL) |
175f072e KM |
352 | return; |
353 | ||
354 | again: | |
888963d8 MH |
355 | /* |
356 | * Wait until the pageout daemon is through with the object. | |
357 | */ | |
358 | while (object->paging_in_progress) { | |
359 | vm_object_sleep((int)object, object, FALSE); | |
360 | vm_object_lock(object); | |
361 | } | |
362 | /* | |
363 | * Loop through the object page list cleaning as necessary. | |
364 | */ | |
175f072e KM |
365 | p = (vm_page_t) queue_first(&object->memq); |
366 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
367 | if (start == end || | |
368 | p->offset >= start && p->offset < end) { | |
2cbf9af3 KM |
369 | if ((p->flags & PG_CLEAN) && |
370 | pmap_is_modified(VM_PAGE_TO_PHYS(p))) | |
371 | p->flags &= ~PG_CLEAN; | |
888963d8 MH |
372 | /* |
373 | * Remove the page from any paging queue. | |
374 | * This needs to be done if either we have been | |
375 | * explicitly asked to do so or it is about to | |
376 | * be cleaned (see comment below). | |
377 | */ | |
2cbf9af3 | 378 | if (de_queue || !(p->flags & PG_CLEAN)) { |
888963d8 | 379 | vm_page_lock_queues(); |
2cbf9af3 | 380 | if (p->flags & PG_ACTIVE) { |
888963d8 MH |
381 | queue_remove(&vm_page_queue_active, |
382 | p, vm_page_t, pageq); | |
2cbf9af3 | 383 | p->flags &= ~PG_ACTIVE; |
888963d8 MH |
384 | cnt.v_active_count--; |
385 | onqueue = 1; | |
2cbf9af3 | 386 | } else if (p->flags & PG_INACTIVE) { |
888963d8 MH |
387 | queue_remove(&vm_page_queue_inactive, |
388 | p, vm_page_t, pageq); | |
2cbf9af3 | 389 | p->flags &= ~PG_INACTIVE; |
888963d8 MH |
390 | cnt.v_inactive_count--; |
391 | onqueue = -1; | |
392 | } else | |
393 | onqueue = 0; | |
394 | vm_page_unlock_queues(); | |
395 | } | |
396 | /* | |
397 | * To ensure the state of the page doesn't change | |
398 | * during the clean operation we do two things. | |
399 | * First we set the busy bit and invalidate all | |
400 | * mappings to ensure that thread accesses to the | |
401 | * page block (in vm_fault). Second, we remove | |
402 | * the page from any paging queue to foil the | |
403 | * pageout daemon (vm_pageout_scan). | |
404 | */ | |
ae1e5b95 | 405 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); |
2cbf9af3 KM |
406 | if (!(p->flags & PG_CLEAN)) { |
407 | p->flags |= PG_BUSY; | |
175f072e KM |
408 | object->paging_in_progress++; |
409 | vm_object_unlock(object); | |
410 | (void) vm_pager_put(object->pager, p, TRUE); | |
411 | vm_object_lock(object); | |
412 | object->paging_in_progress--; | |
25746cce | 413 | if (!de_queue && onqueue) { |
888963d8 MH |
414 | vm_page_lock_queues(); |
415 | if (onqueue > 0) | |
416 | vm_page_activate(p); | |
417 | else | |
418 | vm_page_deactivate(p); | |
419 | vm_page_unlock_queues(); | |
420 | } | |
2cbf9af3 | 421 | p->flags &= ~PG_BUSY; |
175f072e KM |
422 | PAGE_WAKEUP(p); |
423 | goto again; | |
424 | } | |
425 | } | |
426 | p = (vm_page_t) queue_next(&p->listq); | |
427 | } | |
428 | } | |
429 | ||
430 | /* | |
431 | * vm_object_deactivate_pages | |
432 | * | |
433 | * Deactivate all pages in the specified object. (Keep its pages | |
434 | * in memory even though it is no longer referenced.) | |
435 | * | |
436 | * The object must be locked. | |
437 | */ | |
0b1533b1 | 438 | void |
175f072e KM |
439 | vm_object_deactivate_pages(object) |
440 | register vm_object_t object; | |
441 | { | |
442 | register vm_page_t p, next; | |
443 | ||
444 | p = (vm_page_t) queue_first(&object->memq); | |
445 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
446 | next = (vm_page_t) queue_next(&p->listq); | |
447 | vm_page_lock_queues(); | |
448 | vm_page_deactivate(p); | |
449 | vm_page_unlock_queues(); | |
450 | p = next; | |
451 | } | |
452 | } | |
453 | ||
454 | /* | |
455 | * Trim the object cache to size. | |
456 | */ | |
0b1533b1 | 457 | void |
175f072e KM |
458 | vm_object_cache_trim() |
459 | { | |
460 | register vm_object_t object; | |
461 | ||
462 | vm_object_cache_lock(); | |
463 | while (vm_object_cached > vm_cache_max) { | |
464 | object = (vm_object_t) queue_first(&vm_object_cached_list); | |
465 | vm_object_cache_unlock(); | |
466 | ||
467 | if (object != vm_object_lookup(object->pager)) | |
468 | panic("vm_object_deactivate: I'm sooo confused."); | |
469 | ||
470 | pager_cache(object, FALSE); | |
471 | ||
472 | vm_object_cache_lock(); | |
473 | } | |
474 | vm_object_cache_unlock(); | |
475 | } | |
476 | ||
477 | ||
478 | /* | |
479 | * vm_object_shutdown() | |
480 | * | |
481 | * Shut down the object system. Unfortunately, while we | |
482 | * may be trying to do this, init is happily waiting for | |
483 | * processes to exit, and therefore will be causing some objects | |
484 | * to be deallocated. To handle this, we gain a fake reference | |
485 | * to all objects we release paging areas for. This will prevent | |
486 | * a duplicate deallocation. This routine is probably full of | |
487 | * race conditions! | |
488 | */ | |
489 | ||
490 | void vm_object_shutdown() | |
491 | { | |
492 | register vm_object_t object; | |
493 | ||
494 | /* | |
495 | * Clean up the object cache *before* we screw up the reference | |
496 | * counts on all of the objects. | |
497 | */ | |
498 | ||
499 | vm_object_cache_clear(); | |
500 | ||
501 | printf("free paging spaces: "); | |
502 | ||
503 | /* | |
504 | * First we gain a reference to each object so that | |
505 | * no one else will deallocate them. | |
506 | */ | |
507 | ||
508 | simple_lock(&vm_object_list_lock); | |
509 | object = (vm_object_t) queue_first(&vm_object_list); | |
510 | while (!queue_end(&vm_object_list, (queue_entry_t) object)) { | |
511 | vm_object_reference(object); | |
512 | object = (vm_object_t) queue_next(&object->object_list); | |
513 | } | |
514 | simple_unlock(&vm_object_list_lock); | |
515 | ||
516 | /* | |
517 | * Now we deallocate all the paging areas. We don't need | |
518 | * to lock anything because we've reduced to a single | |
519 | * processor while shutting down. This also assumes that | |
520 | * no new objects are being created. | |
521 | */ | |
522 | ||
523 | object = (vm_object_t) queue_first(&vm_object_list); | |
524 | while (!queue_end(&vm_object_list, (queue_entry_t) object)) { | |
ffe0d082 | 525 | if (object->pager != NULL) |
175f072e KM |
526 | vm_pager_deallocate(object->pager); |
527 | object = (vm_object_t) queue_next(&object->object_list); | |
528 | printf("."); | |
529 | } | |
530 | printf("done.\n"); | |
531 | } | |
532 | ||
533 | /* | |
534 | * vm_object_pmap_copy: | |
535 | * | |
536 | * Makes all physical pages in the specified | |
537 | * object range copy-on-write. No writeable | |
538 | * references to these pages should remain. | |
539 | * | |
540 | * The object must *not* be locked. | |
541 | */ | |
542 | void vm_object_pmap_copy(object, start, end) | |
543 | register vm_object_t object; | |
544 | register vm_offset_t start; | |
545 | register vm_offset_t end; | |
546 | { | |
547 | register vm_page_t p; | |
548 | ||
ffe0d082 | 549 | if (object == NULL) |
175f072e KM |
550 | return; |
551 | ||
552 | vm_object_lock(object); | |
553 | p = (vm_page_t) queue_first(&object->memq); | |
554 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
555 | if ((start <= p->offset) && (p->offset < end)) { | |
ae1e5b95 | 556 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_READ); |
2cbf9af3 | 557 | p->flags |= PG_COPYONWRITE; |
175f072e KM |
558 | } |
559 | p = (vm_page_t) queue_next(&p->listq); | |
560 | } | |
561 | vm_object_unlock(object); | |
562 | } | |
563 | ||
564 | /* | |
565 | * vm_object_pmap_remove: | |
566 | * | |
567 | * Removes all physical pages in the specified | |
568 | * object range from all physical maps. | |
569 | * | |
570 | * The object must *not* be locked. | |
571 | */ | |
572 | void vm_object_pmap_remove(object, start, end) | |
573 | register vm_object_t object; | |
574 | register vm_offset_t start; | |
575 | register vm_offset_t end; | |
576 | { | |
577 | register vm_page_t p; | |
578 | ||
ffe0d082 | 579 | if (object == NULL) |
175f072e KM |
580 | return; |
581 | ||
582 | vm_object_lock(object); | |
583 | p = (vm_page_t) queue_first(&object->memq); | |
584 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
ae1e5b95 MH |
585 | if ((start <= p->offset) && (p->offset < end)) |
586 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); | |
175f072e KM |
587 | p = (vm_page_t) queue_next(&p->listq); |
588 | } | |
589 | vm_object_unlock(object); | |
590 | } | |
591 | ||
592 | /* | |
593 | * vm_object_copy: | |
594 | * | |
595 | * Create a new object which is a copy of an existing | |
596 | * object, and mark all of the pages in the existing | |
597 | * object 'copy-on-write'. The new object has one reference. | |
598 | * Returns the new object. | |
599 | * | |
600 | * May defer the copy until later if the object is not backed | |
601 | * up by a non-default pager. | |
602 | */ | |
603 | void vm_object_copy(src_object, src_offset, size, | |
604 | dst_object, dst_offset, src_needs_copy) | |
605 | register vm_object_t src_object; | |
606 | vm_offset_t src_offset; | |
607 | vm_size_t size; | |
608 | vm_object_t *dst_object; /* OUT */ | |
609 | vm_offset_t *dst_offset; /* OUT */ | |
610 | boolean_t *src_needs_copy; /* OUT */ | |
611 | { | |
612 | register vm_object_t new_copy; | |
613 | register vm_object_t old_copy; | |
614 | vm_offset_t new_start, new_end; | |
615 | ||
616 | register vm_page_t p; | |
617 | ||
ffe0d082 | 618 | if (src_object == NULL) { |
175f072e KM |
619 | /* |
620 | * Nothing to copy | |
621 | */ | |
ffe0d082 | 622 | *dst_object = NULL; |
175f072e KM |
623 | *dst_offset = 0; |
624 | *src_needs_copy = FALSE; | |
625 | return; | |
626 | } | |
627 | ||
628 | /* | |
629 | * If the object's pager is null_pager or the | |
630 | * default pager, we don't have to make a copy | |
631 | * of it. Instead, we set the needs copy flag and | |
632 | * make a shadow later. | |
633 | */ | |
634 | ||
635 | vm_object_lock(src_object); | |
ffe0d082 | 636 | if (src_object->pager == NULL || |
d4ab8fb9 | 637 | (src_object->flags & OBJ_INTERNAL)) { |
175f072e KM |
638 | |
639 | /* | |
640 | * Make another reference to the object | |
641 | */ | |
642 | src_object->ref_count++; | |
643 | ||
644 | /* | |
645 | * Mark all of the pages copy-on-write. | |
646 | */ | |
647 | for (p = (vm_page_t) queue_first(&src_object->memq); | |
648 | !queue_end(&src_object->memq, (queue_entry_t)p); | |
649 | p = (vm_page_t) queue_next(&p->listq)) { | |
650 | if (src_offset <= p->offset && | |
651 | p->offset < src_offset + size) | |
2cbf9af3 | 652 | p->flags |= PG_COPYONWRITE; |
175f072e KM |
653 | } |
654 | vm_object_unlock(src_object); | |
655 | ||
656 | *dst_object = src_object; | |
657 | *dst_offset = src_offset; | |
658 | ||
659 | /* | |
660 | * Must make a shadow when write is desired | |
661 | */ | |
662 | *src_needs_copy = TRUE; | |
663 | return; | |
664 | } | |
665 | ||
666 | /* | |
667 | * Try to collapse the object before copying it. | |
668 | */ | |
669 | vm_object_collapse(src_object); | |
670 | ||
671 | /* | |
672 | * If the object has a pager, the pager wants to | |
673 | * see all of the changes. We need a copy-object | |
674 | * for the changed pages. | |
675 | * | |
676 | * If there is a copy-object, and it is empty, | |
677 | * no changes have been made to the object since the | |
678 | * copy-object was made. We can use the same copy- | |
679 | * object. | |
680 | */ | |
681 | ||
682 | Retry1: | |
683 | old_copy = src_object->copy; | |
ffe0d082 | 684 | if (old_copy != NULL) { |
175f072e KM |
685 | /* |
686 | * Try to get the locks (out of order) | |
687 | */ | |
688 | if (!vm_object_lock_try(old_copy)) { | |
689 | vm_object_unlock(src_object); | |
690 | ||
691 | /* should spin a bit here... */ | |
692 | vm_object_lock(src_object); | |
693 | goto Retry1; | |
694 | } | |
695 | ||
696 | if (old_copy->resident_page_count == 0 && | |
ffe0d082 | 697 | old_copy->pager == NULL) { |
175f072e KM |
698 | /* |
699 | * Return another reference to | |
700 | * the existing copy-object. | |
701 | */ | |
702 | old_copy->ref_count++; | |
703 | vm_object_unlock(old_copy); | |
704 | vm_object_unlock(src_object); | |
705 | *dst_object = old_copy; | |
706 | *dst_offset = src_offset; | |
707 | *src_needs_copy = FALSE; | |
708 | return; | |
709 | } | |
710 | vm_object_unlock(old_copy); | |
711 | } | |
712 | vm_object_unlock(src_object); | |
713 | ||
714 | /* | |
715 | * If the object has a pager, the pager wants | |
716 | * to see all of the changes. We must make | |
717 | * a copy-object and put the changed pages there. | |
718 | * | |
719 | * The copy-object is always made large enough to | |
720 | * completely shadow the original object, since | |
721 | * it may have several users who want to shadow | |
722 | * the original object at different points. | |
723 | */ | |
724 | ||
725 | new_copy = vm_object_allocate(src_object->size); | |
726 | ||
727 | Retry2: | |
728 | vm_object_lock(src_object); | |
729 | /* | |
730 | * Copy object may have changed while we were unlocked | |
731 | */ | |
732 | old_copy = src_object->copy; | |
ffe0d082 | 733 | if (old_copy != NULL) { |
175f072e KM |
734 | /* |
735 | * Try to get the locks (out of order) | |
736 | */ | |
737 | if (!vm_object_lock_try(old_copy)) { | |
738 | vm_object_unlock(src_object); | |
739 | goto Retry2; | |
740 | } | |
741 | ||
742 | /* | |
743 | * Consistency check | |
744 | */ | |
745 | if (old_copy->shadow != src_object || | |
746 | old_copy->shadow_offset != (vm_offset_t) 0) | |
747 | panic("vm_object_copy: copy/shadow inconsistency"); | |
748 | ||
749 | /* | |
750 | * Make the old copy-object shadow the new one. | |
751 | * It will receive no more pages from the original | |
752 | * object. | |
753 | */ | |
754 | ||
755 | src_object->ref_count--; /* remove ref. from old_copy */ | |
756 | old_copy->shadow = new_copy; | |
757 | new_copy->ref_count++; /* locking not needed - we | |
758 | have the only pointer */ | |
759 | vm_object_unlock(old_copy); /* done with old_copy */ | |
760 | } | |
761 | ||
762 | new_start = (vm_offset_t) 0; /* always shadow original at 0 */ | |
763 | new_end = (vm_offset_t) new_copy->size; /* for the whole object */ | |
764 | ||
765 | /* | |
766 | * Point the new copy at the existing object. | |
767 | */ | |
768 | ||
769 | new_copy->shadow = src_object; | |
770 | new_copy->shadow_offset = new_start; | |
771 | src_object->ref_count++; | |
772 | src_object->copy = new_copy; | |
773 | ||
774 | /* | |
775 | * Mark all the affected pages of the existing object | |
776 | * copy-on-write. | |
777 | */ | |
778 | p = (vm_page_t) queue_first(&src_object->memq); | |
779 | while (!queue_end(&src_object->memq, (queue_entry_t) p)) { | |
ae1e5b95 | 780 | if ((new_start <= p->offset) && (p->offset < new_end)) |
2cbf9af3 | 781 | p->flags |= PG_COPYONWRITE; |
175f072e KM |
782 | p = (vm_page_t) queue_next(&p->listq); |
783 | } | |
784 | ||
785 | vm_object_unlock(src_object); | |
786 | ||
787 | *dst_object = new_copy; | |
788 | *dst_offset = src_offset - new_start; | |
789 | *src_needs_copy = FALSE; | |
790 | } | |
791 | ||
792 | /* | |
793 | * vm_object_shadow: | |
794 | * | |
795 | * Create a new object which is backed by the | |
796 | * specified existing object range. The source | |
797 | * object reference is deallocated. | |
798 | * | |
799 | * The new object and offset into that object | |
800 | * are returned in the source parameters. | |
801 | */ | |
802 | ||
803 | void vm_object_shadow(object, offset, length) | |
804 | vm_object_t *object; /* IN/OUT */ | |
805 | vm_offset_t *offset; /* IN/OUT */ | |
806 | vm_size_t length; | |
807 | { | |
808 | register vm_object_t source; | |
809 | register vm_object_t result; | |
810 | ||
811 | source = *object; | |
812 | ||
813 | /* | |
814 | * Allocate a new object with the given length | |
815 | */ | |
816 | ||
ffe0d082 | 817 | if ((result = vm_object_allocate(length)) == NULL) |
175f072e KM |
818 | panic("vm_object_shadow: no object for shadowing"); |
819 | ||
820 | /* | |
821 | * The new object shadows the source object, adding | |
822 | * a reference to it. Our caller changes his reference | |
823 | * to point to the new object, removing a reference to | |
824 | * the source object. Net result: no change of reference | |
825 | * count. | |
826 | */ | |
827 | result->shadow = source; | |
828 | ||
829 | /* | |
830 | * Store the offset into the source object, | |
831 | * and fix up the offset into the new object. | |
832 | */ | |
833 | ||
834 | result->shadow_offset = *offset; | |
835 | ||
836 | /* | |
837 | * Return the new things | |
838 | */ | |
839 | ||
840 | *offset = 0; | |
841 | *object = result; | |
842 | } | |
843 | ||
844 | /* | |
845 | * Set the specified object's pager to the specified pager. | |
846 | */ | |
847 | ||
848 | void vm_object_setpager(object, pager, paging_offset, | |
849 | read_only) | |
850 | vm_object_t object; | |
851 | vm_pager_t pager; | |
852 | vm_offset_t paging_offset; | |
853 | boolean_t read_only; | |
854 | { | |
855 | #ifdef lint | |
856 | read_only++; /* No longer used */ | |
1524bcb8 | 857 | #endif |
175f072e KM |
858 | |
859 | vm_object_lock(object); /* XXX ? */ | |
860 | object->pager = pager; | |
861 | object->paging_offset = paging_offset; | |
862 | vm_object_unlock(object); /* XXX ? */ | |
863 | } | |
864 | ||
865 | /* | |
866 | * vm_object_hash hashes the pager/id pair. | |
867 | */ | |
868 | ||
869 | #define vm_object_hash(pager) \ | |
870 | (((unsigned)pager)%VM_OBJECT_HASH_COUNT) | |
871 | ||
872 | /* | |
873 | * vm_object_lookup looks in the object cache for an object with the | |
874 | * specified pager and paging id. | |
875 | */ | |
876 | ||
877 | vm_object_t vm_object_lookup(pager) | |
878 | vm_pager_t pager; | |
879 | { | |
880 | register queue_t bucket; | |
881 | register vm_object_hash_entry_t entry; | |
882 | vm_object_t object; | |
883 | ||
884 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
885 | ||
886 | vm_object_cache_lock(); | |
887 | ||
888 | entry = (vm_object_hash_entry_t) queue_first(bucket); | |
889 | while (!queue_end(bucket, (queue_entry_t) entry)) { | |
890 | object = entry->object; | |
891 | if (object->pager == pager) { | |
892 | vm_object_lock(object); | |
893 | if (object->ref_count == 0) { | |
894 | queue_remove(&vm_object_cached_list, object, | |
895 | vm_object_t, cached_list); | |
896 | vm_object_cached--; | |
897 | } | |
898 | object->ref_count++; | |
899 | vm_object_unlock(object); | |
900 | vm_object_cache_unlock(); | |
901 | return(object); | |
902 | } | |
903 | entry = (vm_object_hash_entry_t) queue_next(&entry->hash_links); | |
904 | } | |
905 | ||
906 | vm_object_cache_unlock(); | |
ffe0d082 | 907 | return(NULL); |
175f072e KM |
908 | } |
909 | ||
910 | /* | |
911 | * vm_object_enter enters the specified object/pager/id into | |
912 | * the hash table. | |
913 | */ | |
914 | ||
915 | void vm_object_enter(object, pager) | |
916 | vm_object_t object; | |
917 | vm_pager_t pager; | |
918 | { | |
919 | register queue_t bucket; | |
920 | register vm_object_hash_entry_t entry; | |
921 | ||
922 | /* | |
923 | * We don't cache null objects, and we can't cache | |
924 | * objects with the null pager. | |
925 | */ | |
926 | ||
ffe0d082 | 927 | if (object == NULL) |
175f072e | 928 | return; |
ffe0d082 | 929 | if (pager == NULL) |
175f072e KM |
930 | return; |
931 | ||
932 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
933 | entry = (vm_object_hash_entry_t) | |
934 | malloc((u_long)sizeof *entry, M_VMOBJHASH, M_WAITOK); | |
935 | entry->object = object; | |
d4ab8fb9 | 936 | object->flags |= OBJ_CANPERSIST; |
175f072e KM |
937 | |
938 | vm_object_cache_lock(); | |
939 | queue_enter(bucket, entry, vm_object_hash_entry_t, hash_links); | |
940 | vm_object_cache_unlock(); | |
941 | } | |
942 | ||
943 | /* | |
944 | * vm_object_remove: | |
945 | * | |
946 | * Remove the pager from the hash table. | |
947 | * Note: This assumes that the object cache | |
948 | * is locked. XXX this should be fixed | |
949 | * by reorganizing vm_object_deallocate. | |
950 | */ | |
0b1533b1 | 951 | void |
175f072e KM |
952 | vm_object_remove(pager) |
953 | register vm_pager_t pager; | |
954 | { | |
955 | register queue_t bucket; | |
956 | register vm_object_hash_entry_t entry; | |
957 | register vm_object_t object; | |
958 | ||
959 | bucket = &vm_object_hashtable[vm_object_hash(pager)]; | |
960 | ||
961 | entry = (vm_object_hash_entry_t) queue_first(bucket); | |
962 | while (!queue_end(bucket, (queue_entry_t) entry)) { | |
963 | object = entry->object; | |
964 | if (object->pager == pager) { | |
965 | queue_remove(bucket, entry, vm_object_hash_entry_t, | |
966 | hash_links); | |
967 | free((caddr_t)entry, M_VMOBJHASH); | |
968 | break; | |
969 | } | |
970 | entry = (vm_object_hash_entry_t) queue_next(&entry->hash_links); | |
971 | } | |
972 | } | |
973 | ||
974 | /* | |
975 | * vm_object_cache_clear removes all objects from the cache. | |
976 | * | |
977 | */ | |
978 | ||
979 | void vm_object_cache_clear() | |
980 | { | |
981 | register vm_object_t object; | |
982 | ||
983 | /* | |
984 | * Remove each object in the cache by scanning down the | |
985 | * list of cached objects. | |
986 | */ | |
987 | vm_object_cache_lock(); | |
988 | while (!queue_empty(&vm_object_cached_list)) { | |
989 | object = (vm_object_t) queue_first(&vm_object_cached_list); | |
990 | vm_object_cache_unlock(); | |
991 | ||
992 | /* | |
993 | * Note: it is important that we use vm_object_lookup | |
994 | * to gain a reference, and not vm_object_reference, because | |
995 | * the logic for removing an object from the cache lies in | |
996 | * lookup. | |
997 | */ | |
998 | if (object != vm_object_lookup(object->pager)) | |
999 | panic("vm_object_cache_clear: I'm sooo confused."); | |
1000 | pager_cache(object, FALSE); | |
1001 | ||
1002 | vm_object_cache_lock(); | |
1003 | } | |
1004 | vm_object_cache_unlock(); | |
1005 | } | |
1006 | ||
1007 | boolean_t vm_object_collapse_allowed = TRUE; | |
1008 | /* | |
1009 | * vm_object_collapse: | |
1010 | * | |
1011 | * Collapse an object with the object backing it. | |
1012 | * Pages in the backing object are moved into the | |
1013 | * parent, and the backing object is deallocated. | |
1014 | * | |
1015 | * Requires that the object be locked and the page | |
1016 | * queues be unlocked. | |
1017 | * | |
1018 | */ | |
1019 | void vm_object_collapse(object) | |
1020 | register vm_object_t object; | |
1021 | ||
1022 | { | |
1023 | register vm_object_t backing_object; | |
1024 | register vm_offset_t backing_offset; | |
1025 | register vm_size_t size; | |
1026 | register vm_offset_t new_offset; | |
1027 | register vm_page_t p, pp; | |
1028 | ||
1029 | if (!vm_object_collapse_allowed) | |
1030 | return; | |
1031 | ||
1032 | while (TRUE) { | |
1033 | /* | |
1034 | * Verify that the conditions are right for collapse: | |
1035 | * | |
1036 | * The object exists and no pages in it are currently | |
1037 | * being paged out (or have ever been paged out). | |
1038 | */ | |
ffe0d082 | 1039 | if (object == NULL || |
175f072e | 1040 | object->paging_in_progress != 0 || |
ffe0d082 | 1041 | object->pager != NULL) |
175f072e KM |
1042 | return; |
1043 | ||
1044 | /* | |
1045 | * There is a backing object, and | |
1046 | */ | |
1047 | ||
ffe0d082 | 1048 | if ((backing_object = object->shadow) == NULL) |
175f072e KM |
1049 | return; |
1050 | ||
1051 | vm_object_lock(backing_object); | |
1052 | /* | |
1053 | * ... | |
1054 | * The backing object is not read_only, | |
1055 | * and no pages in the backing object are | |
1056 | * currently being paged out. | |
1057 | * The backing object is internal. | |
1058 | */ | |
1059 | ||
d4ab8fb9 | 1060 | if ((backing_object->flags & OBJ_INTERNAL) == 0 || |
175f072e KM |
1061 | backing_object->paging_in_progress != 0) { |
1062 | vm_object_unlock(backing_object); | |
1063 | return; | |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * The backing object can't be a copy-object: | |
1068 | * the shadow_offset for the copy-object must stay | |
1069 | * as 0. Furthermore (for the 'we have all the | |
1070 | * pages' case), if we bypass backing_object and | |
1071 | * just shadow the next object in the chain, old | |
1072 | * pages from that object would then have to be copied | |
1073 | * BOTH into the (former) backing_object and into the | |
1074 | * parent object. | |
1075 | */ | |
ffe0d082 MK |
1076 | if (backing_object->shadow != NULL && |
1077 | backing_object->shadow->copy != NULL) { | |
175f072e KM |
1078 | vm_object_unlock(backing_object); |
1079 | return; | |
1080 | } | |
1081 | ||
1082 | /* | |
1083 | * We know that we can either collapse the backing | |
1084 | * object (if the parent is the only reference to | |
1085 | * it) or (perhaps) remove the parent's reference | |
1086 | * to it. | |
1087 | */ | |
1088 | ||
1089 | backing_offset = object->shadow_offset; | |
1090 | size = object->size; | |
1091 | ||
1092 | /* | |
1093 | * If there is exactly one reference to the backing | |
1094 | * object, we can collapse it into the parent. | |
1095 | */ | |
1096 | ||
1097 | if (backing_object->ref_count == 1) { | |
1098 | ||
1099 | /* | |
1100 | * We can collapse the backing object. | |
1101 | * | |
1102 | * Move all in-memory pages from backing_object | |
1103 | * to the parent. Pages that have been paged out | |
1104 | * will be overwritten by any of the parent's | |
1105 | * pages that shadow them. | |
1106 | */ | |
1107 | ||
1108 | while (!queue_empty(&backing_object->memq)) { | |
1109 | ||
1110 | p = (vm_page_t) | |
1111 | queue_first(&backing_object->memq); | |
1112 | ||
1113 | new_offset = (p->offset - backing_offset); | |
1114 | ||
1115 | /* | |
1116 | * If the parent has a page here, or if | |
1117 | * this page falls outside the parent, | |
1118 | * dispose of it. | |
1119 | * | |
1120 | * Otherwise, move it as planned. | |
1121 | */ | |
1122 | ||
1123 | if (p->offset < backing_offset || | |
1124 | new_offset >= size) { | |
1125 | vm_page_lock_queues(); | |
1126 | vm_page_free(p); | |
1127 | vm_page_unlock_queues(); | |
1128 | } else { | |
1129 | pp = vm_page_lookup(object, new_offset); | |
2cbf9af3 | 1130 | if (pp != NULL && !(pp->flags & PG_FAKE)) { |
175f072e KM |
1131 | vm_page_lock_queues(); |
1132 | vm_page_free(p); | |
1133 | vm_page_unlock_queues(); | |
1134 | } | |
1135 | else { | |
1136 | if (pp) { | |
1137 | /* may be someone waiting for it */ | |
1138 | PAGE_WAKEUP(pp); | |
1139 | vm_page_lock_queues(); | |
1140 | vm_page_free(pp); | |
1141 | vm_page_unlock_queues(); | |
1142 | } | |
1143 | vm_page_rename(p, object, new_offset); | |
1144 | } | |
1145 | } | |
1146 | } | |
1147 | ||
1148 | /* | |
1149 | * Move the pager from backing_object to object. | |
1150 | * | |
1151 | * XXX We're only using part of the paging space | |
1152 | * for keeps now... we ought to discard the | |
1153 | * unused portion. | |
1154 | */ | |
1155 | ||
1156 | object->pager = backing_object->pager; | |
1157 | object->paging_offset += backing_offset; | |
1158 | ||
ffe0d082 | 1159 | backing_object->pager = NULL; |
175f072e KM |
1160 | |
1161 | /* | |
1162 | * Object now shadows whatever backing_object did. | |
1163 | * Note that the reference to backing_object->shadow | |
1164 | * moves from within backing_object to within object. | |
1165 | */ | |
1166 | ||
1167 | object->shadow = backing_object->shadow; | |
1168 | object->shadow_offset += backing_object->shadow_offset; | |
ffe0d082 MK |
1169 | if (object->shadow != NULL && |
1170 | object->shadow->copy != NULL) { | |
175f072e KM |
1171 | panic("vm_object_collapse: we collapsed a copy-object!"); |
1172 | } | |
1173 | /* | |
1174 | * Discard backing_object. | |
1175 | * | |
1176 | * Since the backing object has no pages, no | |
1177 | * pager left, and no object references within it, | |
1178 | * all that is necessary is to dispose of it. | |
1179 | */ | |
1180 | ||
1181 | vm_object_unlock(backing_object); | |
1182 | ||
1183 | simple_lock(&vm_object_list_lock); | |
1184 | queue_remove(&vm_object_list, backing_object, | |
1185 | vm_object_t, object_list); | |
1186 | vm_object_count--; | |
1187 | simple_unlock(&vm_object_list_lock); | |
1188 | ||
1189 | free((caddr_t)backing_object, M_VMOBJ); | |
1190 | ||
1191 | object_collapses++; | |
1192 | } | |
1193 | else { | |
1194 | /* | |
1195 | * If all of the pages in the backing object are | |
1196 | * shadowed by the parent object, the parent | |
1197 | * object no longer has to shadow the backing | |
1198 | * object; it can shadow the next one in the | |
1199 | * chain. | |
1200 | * | |
1201 | * The backing object must not be paged out - we'd | |
1202 | * have to check all of the paged-out pages, as | |
1203 | * well. | |
1204 | */ | |
1205 | ||
ffe0d082 | 1206 | if (backing_object->pager != NULL) { |
175f072e KM |
1207 | vm_object_unlock(backing_object); |
1208 | return; | |
1209 | } | |
1210 | ||
1211 | /* | |
1212 | * Should have a check for a 'small' number | |
1213 | * of pages here. | |
1214 | */ | |
1215 | ||
1216 | p = (vm_page_t) queue_first(&backing_object->memq); | |
1217 | while (!queue_end(&backing_object->memq, | |
1218 | (queue_entry_t) p)) { | |
1219 | ||
1220 | new_offset = (p->offset - backing_offset); | |
1221 | ||
1222 | /* | |
1223 | * If the parent has a page here, or if | |
1224 | * this page falls outside the parent, | |
1225 | * keep going. | |
1226 | * | |
1227 | * Otherwise, the backing_object must be | |
1228 | * left in the chain. | |
1229 | */ | |
1230 | ||
1231 | if (p->offset >= backing_offset && | |
1232 | new_offset <= size && | |
1233 | ((pp = vm_page_lookup(object, new_offset)) | |
ffe0d082 | 1234 | == NULL || |
2cbf9af3 | 1235 | (pp->flags & PG_FAKE))) { |
175f072e KM |
1236 | /* |
1237 | * Page still needed. | |
1238 | * Can't go any further. | |
1239 | */ | |
1240 | vm_object_unlock(backing_object); | |
1241 | return; | |
1242 | } | |
1243 | p = (vm_page_t) queue_next(&p->listq); | |
1244 | } | |
1245 | ||
1246 | /* | |
1247 | * Make the parent shadow the next object | |
1248 | * in the chain. Deallocating backing_object | |
1249 | * will not remove it, since its reference | |
1250 | * count is at least 2. | |
1251 | */ | |
1252 | ||
1253 | vm_object_reference(object->shadow = backing_object->shadow); | |
1254 | object->shadow_offset += backing_object->shadow_offset; | |
1255 | ||
1256 | /* Drop the reference count on backing_object. | |
1257 | * Since its ref_count was at least 2, it | |
1258 | * will not vanish; so we don't need to call | |
1259 | * vm_object_deallocate. | |
1260 | */ | |
1261 | backing_object->ref_count--; | |
1262 | vm_object_unlock(backing_object); | |
1263 | ||
1264 | object_bypasses ++; | |
1265 | ||
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * Try again with this object's new backing object. | |
1270 | */ | |
1271 | } | |
1272 | } | |
1273 | ||
1274 | /* | |
1275 | * vm_object_page_remove: [internal] | |
1276 | * | |
1277 | * Removes all physical pages in the specified | |
1278 | * object range from the object's list of pages. | |
1279 | * | |
1280 | * The object must be locked. | |
1281 | */ | |
1282 | void vm_object_page_remove(object, start, end) | |
1283 | register vm_object_t object; | |
1284 | register vm_offset_t start; | |
1285 | register vm_offset_t end; | |
1286 | { | |
1287 | register vm_page_t p, next; | |
1288 | ||
ffe0d082 | 1289 | if (object == NULL) |
175f072e KM |
1290 | return; |
1291 | ||
1292 | p = (vm_page_t) queue_first(&object->memq); | |
1293 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
1294 | next = (vm_page_t) queue_next(&p->listq); | |
1295 | if ((start <= p->offset) && (p->offset < end)) { | |
ae1e5b95 | 1296 | pmap_page_protect(VM_PAGE_TO_PHYS(p), VM_PROT_NONE); |
175f072e KM |
1297 | vm_page_lock_queues(); |
1298 | vm_page_free(p); | |
1299 | vm_page_unlock_queues(); | |
1300 | } | |
1301 | p = next; | |
1302 | } | |
1303 | } | |
1304 | ||
1305 | /* | |
1306 | * Routine: vm_object_coalesce | |
1307 | * Function: Coalesces two objects backing up adjoining | |
1308 | * regions of memory into a single object. | |
1309 | * | |
1310 | * returns TRUE if objects were combined. | |
1311 | * | |
1312 | * NOTE: Only works at the moment if the second object is NULL - | |
1313 | * if it's not, which object do we lock first? | |
1314 | * | |
1315 | * Parameters: | |
1316 | * prev_object First object to coalesce | |
1317 | * prev_offset Offset into prev_object | |
1318 | * next_object Second object into coalesce | |
1319 | * next_offset Offset into next_object | |
1320 | * | |
1321 | * prev_size Size of reference to prev_object | |
1322 | * next_size Size of reference to next_object | |
1323 | * | |
1324 | * Conditions: | |
1325 | * The object must *not* be locked. | |
1326 | */ | |
1327 | boolean_t vm_object_coalesce(prev_object, next_object, | |
1328 | prev_offset, next_offset, | |
1329 | prev_size, next_size) | |
1330 | ||
1331 | register vm_object_t prev_object; | |
1332 | vm_object_t next_object; | |
1333 | vm_offset_t prev_offset, next_offset; | |
1334 | vm_size_t prev_size, next_size; | |
1335 | { | |
1336 | vm_size_t newsize; | |
1337 | ||
1338 | #ifdef lint | |
1339 | next_offset++; | |
1524bcb8 | 1340 | #endif |
175f072e | 1341 | |
ffe0d082 | 1342 | if (next_object != NULL) { |
175f072e KM |
1343 | return(FALSE); |
1344 | } | |
1345 | ||
ffe0d082 | 1346 | if (prev_object == NULL) { |
175f072e KM |
1347 | return(TRUE); |
1348 | } | |
1349 | ||
1350 | vm_object_lock(prev_object); | |
1351 | ||
1352 | /* | |
1353 | * Try to collapse the object first | |
1354 | */ | |
1355 | vm_object_collapse(prev_object); | |
1356 | ||
1357 | /* | |
1358 | * Can't coalesce if: | |
1359 | * . more than one reference | |
1360 | * . paged out | |
1361 | * . shadows another object | |
1362 | * . has a copy elsewhere | |
1363 | * (any of which mean that the pages not mapped to | |
1364 | * prev_entry may be in use anyway) | |
1365 | */ | |
1366 | ||
1367 | if (prev_object->ref_count > 1 || | |
ffe0d082 MK |
1368 | prev_object->pager != NULL || |
1369 | prev_object->shadow != NULL || | |
1370 | prev_object->copy != NULL) { | |
175f072e KM |
1371 | vm_object_unlock(prev_object); |
1372 | return(FALSE); | |
1373 | } | |
1374 | ||
1375 | /* | |
1376 | * Remove any pages that may still be in the object from | |
1377 | * a previous deallocation. | |
1378 | */ | |
1379 | ||
1380 | vm_object_page_remove(prev_object, | |
1381 | prev_offset + prev_size, | |
1382 | prev_offset + prev_size + next_size); | |
1383 | ||
1384 | /* | |
1385 | * Extend the object if necessary. | |
1386 | */ | |
1387 | newsize = prev_offset + prev_size + next_size; | |
1388 | if (newsize > prev_object->size) | |
1389 | prev_object->size = newsize; | |
1390 | ||
1391 | vm_object_unlock(prev_object); | |
1392 | return(TRUE); | |
1393 | } | |
1394 | ||
1395 | /* | |
1396 | * vm_object_print: [ debug ] | |
1397 | */ | |
1398 | void vm_object_print(object, full) | |
1399 | vm_object_t object; | |
1400 | boolean_t full; | |
1401 | { | |
1402 | register vm_page_t p; | |
1403 | extern indent; | |
1404 | ||
1405 | register int count; | |
1406 | ||
ffe0d082 | 1407 | if (object == NULL) |
175f072e KM |
1408 | return; |
1409 | ||
1410 | iprintf("Object 0x%x: size=0x%x, res=%d, ref=%d, ", | |
1411 | (int) object, (int) object->size, | |
1412 | object->resident_page_count, object->ref_count); | |
1413 | printf("pager=0x%x+0x%x, shadow=(0x%x)+0x%x\n", | |
1414 | (int) object->pager, (int) object->paging_offset, | |
1415 | (int) object->shadow, (int) object->shadow_offset); | |
1416 | printf("cache: next=0x%x, prev=0x%x\n", | |
e0e22745 | 1417 | object->cached_list.qe_next, object->cached_list.qe_prev); |
175f072e KM |
1418 | |
1419 | if (!full) | |
1420 | return; | |
1421 | ||
1422 | indent += 2; | |
1423 | count = 0; | |
1424 | p = (vm_page_t) queue_first(&object->memq); | |
1425 | while (!queue_end(&object->memq, (queue_entry_t) p)) { | |
1426 | if (count == 0) | |
1427 | iprintf("memory:="); | |
1428 | else if (count == 6) { | |
1429 | printf("\n"); | |
1430 | iprintf(" ..."); | |
1431 | count = 0; | |
1432 | } else | |
1433 | printf(","); | |
1434 | count++; | |
1435 | ||
1436 | printf("(off=0x%x,page=0x%x)", p->offset, VM_PAGE_TO_PHYS(p)); | |
1437 | p = (vm_page_t) queue_next(&p->listq); | |
1438 | } | |
1439 | if (count != 0) | |
1440 | printf("\n"); | |
1441 | indent -= 2; | |
1442 | } |