1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 * 64 * $FreeBSD$ 65 */ 66 67 /* 68 * Virtual memory object module. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/lock.h> 74 #include <sys/mman.h> 75 #include <sys/mount.h> 76 #include <sys/mutex.h> 77 #include <sys/proc.h> /* for curproc, pageproc */ 78 #include <sys/socket.h> 79 #include <sys/vnode.h> 80 #include <sys/vmmeter.h> 81 #include <sys/sx.h> 82 83 #include <vm/vm.h> 84 #include <vm/vm_param.h> 85 #include <vm/pmap.h> 86 #include <vm/vm_map.h> 87 #include <vm/vm_object.h> 88 #include <vm/vm_page.h> 89 #include <vm/vm_pageout.h> 90 #include <vm/vm_pager.h> 91 #include <vm/vm_zone.h> 92 #include <vm/swap_pager.h> 93 #include <vm/vm_kern.h> 94 #include <vm/vm_extern.h> 95 96 static void vm_object_qcollapse __P((vm_object_t object)); 97 98 /* 99 * Virtual memory objects maintain the actual data 100 * associated with allocated virtual memory. A given 101 * page of memory exists within exactly one object. 102 * 103 * An object is only deallocated when all "references" 104 * are given up. Only one "reference" to a given 105 * region of an object should be writeable. 106 * 107 * Associated with each object is a list of all resident 108 * memory pages belonging to that object; this list is 109 * maintained by the "vm_page" module, and locked by the object's 110 * lock. 111 * 112 * Each object also records a "pager" routine which is 113 * used to retrieve (and store) pages to the proper backing 114 * storage. In addition, objects may be backed by other 115 * objects from which they were virtual-copied. 116 * 117 * The only items within the object structure which are 118 * modified after time of creation are: 119 * reference count locked by object's lock 120 * pager routine locked by object's lock 121 * 122 */ 123 124 struct object_q vm_object_list; 125 static struct mtx vm_object_list_mtx; /* lock for object list and count */ 126 static long vm_object_count; /* count of all objects */ 127 vm_object_t kernel_object; 128 vm_object_t kmem_object; 129 static struct vm_object kernel_object_store; 130 static struct vm_object kmem_object_store; 131 extern int vm_pageout_page_count; 132 133 static long object_collapses; 134 static long object_bypasses; 135 static int next_index; 136 static vm_zone_t obj_zone; 137 static struct vm_zone obj_zone_store; 138 static int object_hash_rand; 139 #define VM_OBJECTS_INIT 256 140 static struct vm_object vm_objects_init[VM_OBJECTS_INIT]; 141 142 void 143 _vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object) 144 { 145 int incr; 146 147 GIANT_REQUIRED; 148 149 TAILQ_INIT(&object->memq); 150 TAILQ_INIT(&object->shadow_head); 151 152 object->type = type; 153 object->size = size; 154 object->ref_count = 1; 155 object->flags = 0; 156 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 157 vm_object_set_flag(object, OBJ_ONEMAPPING); 158 object->paging_in_progress = 0; 159 object->resident_page_count = 0; 160 object->shadow_count = 0; 161 object->pg_color = next_index; 162 if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 163 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 164 else 165 incr = size; 166 next_index = (next_index + incr) & PQ_L2_MASK; 167 object->handle = NULL; 168 object->backing_object = NULL; 169 object->backing_object_offset = (vm_ooffset_t) 0; 170 /* 171 * Try to generate a number that will spread objects out in the 172 * hash table. We 'wipe' new objects across the hash in 128 page 173 * increments plus 1 more to offset it a little more by the time 174 * it wraps around. 175 */ 176 object->hash_rand = object_hash_rand - 129; 177 178 object->generation++; 179 180 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 181 vm_object_count++; 182 object_hash_rand = object->hash_rand; 183 } 184 185 /* 186 * vm_object_init: 187 * 188 * Initialize the VM objects module. 189 */ 190 void 191 vm_object_init(void) 192 { 193 GIANT_REQUIRED; 194 195 TAILQ_INIT(&vm_object_list); 196 mtx_init(&vm_object_list_mtx, "vm object_list", MTX_DEF); 197 vm_object_count = 0; 198 199 kernel_object = &kernel_object_store; 200 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 201 kernel_object); 202 203 kmem_object = &kmem_object_store; 204 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 205 kmem_object); 206 207 obj_zone = &obj_zone_store; 208 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object), 209 vm_objects_init, VM_OBJECTS_INIT); 210 } 211 212 void 213 vm_object_init2(void) 214 { 215 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1); 216 } 217 218 void 219 vm_object_set_flag(vm_object_t object, u_short bits) 220 { 221 GIANT_REQUIRED; 222 object->flags |= bits; 223 } 224 225 void 226 vm_object_clear_flag(vm_object_t object, u_short bits) 227 { 228 GIANT_REQUIRED; 229 object->flags &= ~bits; 230 } 231 232 void 233 vm_object_pip_add(vm_object_t object, short i) 234 { 235 GIANT_REQUIRED; 236 object->paging_in_progress += i; 237 } 238 239 void 240 vm_object_pip_subtract(vm_object_t object, short i) 241 { 242 GIANT_REQUIRED; 243 object->paging_in_progress -= i; 244 } 245 246 void 247 vm_object_pip_wakeup(vm_object_t object) 248 { 249 GIANT_REQUIRED; 250 object->paging_in_progress--; 251 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 252 vm_object_clear_flag(object, OBJ_PIPWNT); 253 wakeup(object); 254 } 255 } 256 257 void 258 vm_object_pip_wakeupn(vm_object_t object, short i) 259 { 260 GIANT_REQUIRED; 261 if (i) 262 object->paging_in_progress -= i; 263 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 264 vm_object_clear_flag(object, OBJ_PIPWNT); 265 wakeup(object); 266 } 267 } 268 269 void 270 vm_object_pip_sleep(vm_object_t object, char *waitid) 271 { 272 GIANT_REQUIRED; 273 if (object->paging_in_progress) { 274 int s = splvm(); 275 if (object->paging_in_progress) { 276 vm_object_set_flag(object, OBJ_PIPWNT); 277 tsleep(object, PVM, waitid, 0); 278 } 279 splx(s); 280 } 281 } 282 283 void 284 vm_object_pip_wait(vm_object_t object, char *waitid) 285 { 286 GIANT_REQUIRED; 287 while (object->paging_in_progress) 288 vm_object_pip_sleep(object, waitid); 289 } 290 291 /* 292 * vm_object_allocate: 293 * 294 * Returns a new object with the given size. 295 */ 296 297 vm_object_t 298 vm_object_allocate(objtype_t type, vm_size_t size) 299 { 300 vm_object_t result; 301 302 GIANT_REQUIRED; 303 304 result = (vm_object_t) zalloc(obj_zone); 305 _vm_object_allocate(type, size, result); 306 307 return (result); 308 } 309 310 311 /* 312 * vm_object_reference: 313 * 314 * Gets another reference to the given object. 315 */ 316 void 317 vm_object_reference(vm_object_t object) 318 { 319 GIANT_REQUIRED; 320 321 if (object == NULL) 322 return; 323 324 #if 0 325 /* object can be re-referenced during final cleaning */ 326 KASSERT(!(object->flags & OBJ_DEAD), 327 ("vm_object_reference: attempting to reference dead obj")); 328 #endif 329 330 object->ref_count++; 331 if (object->type == OBJT_VNODE) { 332 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) { 333 printf("vm_object_reference: delay in getting object\n"); 334 } 335 } 336 } 337 338 /* 339 * handle deallocating a object of type OBJT_VNODE 340 */ 341 void 342 vm_object_vndeallocate(vm_object_t object) 343 { 344 struct vnode *vp = (struct vnode *) object->handle; 345 346 GIANT_REQUIRED; 347 KASSERT(object->type == OBJT_VNODE, 348 ("vm_object_vndeallocate: not a vnode object")); 349 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 350 #ifdef INVARIANTS 351 if (object->ref_count == 0) { 352 vprint("vm_object_vndeallocate", vp); 353 panic("vm_object_vndeallocate: bad object reference count"); 354 } 355 #endif 356 357 object->ref_count--; 358 if (object->ref_count == 0) { 359 vp->v_flag &= ~VTEXT; 360 vm_object_clear_flag(object, OBJ_OPT); 361 } 362 /* 363 * vrele may need a vop lock 364 */ 365 vrele(vp); 366 } 367 368 /* 369 * vm_object_deallocate: 370 * 371 * Release a reference to the specified object, 372 * gained either through a vm_object_allocate 373 * or a vm_object_reference call. When all references 374 * are gone, storage associated with this object 375 * may be relinquished. 376 * 377 * No object may be locked. 378 */ 379 void 380 vm_object_deallocate(vm_object_t object) 381 { 382 vm_object_t temp; 383 384 GIANT_REQUIRED; 385 386 while (object != NULL) { 387 388 if (object->type == OBJT_VNODE) { 389 vm_object_vndeallocate(object); 390 return; 391 } 392 393 KASSERT(object->ref_count != 0, 394 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 395 396 /* 397 * If the reference count goes to 0 we start calling 398 * vm_object_terminate() on the object chain. 399 * A ref count of 1 may be a special case depending on the 400 * shadow count being 0 or 1. 401 */ 402 object->ref_count--; 403 if (object->ref_count > 1) { 404 return; 405 } else if (object->ref_count == 1) { 406 if (object->shadow_count == 0) { 407 vm_object_set_flag(object, OBJ_ONEMAPPING); 408 } else if ((object->shadow_count == 1) && 409 (object->handle == NULL) && 410 (object->type == OBJT_DEFAULT || 411 object->type == OBJT_SWAP)) { 412 vm_object_t robject; 413 414 robject = TAILQ_FIRST(&object->shadow_head); 415 KASSERT(robject != NULL, 416 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 417 object->ref_count, 418 object->shadow_count)); 419 if ((robject->handle == NULL) && 420 (robject->type == OBJT_DEFAULT || 421 robject->type == OBJT_SWAP)) { 422 423 robject->ref_count++; 424 425 while ( 426 robject->paging_in_progress || 427 object->paging_in_progress 428 ) { 429 vm_object_pip_sleep(robject, "objde1"); 430 vm_object_pip_sleep(object, "objde2"); 431 } 432 433 if (robject->ref_count == 1) { 434 robject->ref_count--; 435 object = robject; 436 goto doterm; 437 } 438 439 object = robject; 440 vm_object_collapse(object); 441 continue; 442 } 443 } 444 445 return; 446 447 } 448 449 doterm: 450 451 temp = object->backing_object; 452 if (temp) { 453 TAILQ_REMOVE(&temp->shadow_head, object, shadow_list); 454 temp->shadow_count--; 455 if (temp->ref_count == 0) 456 vm_object_clear_flag(temp, OBJ_OPT); 457 temp->generation++; 458 object->backing_object = NULL; 459 } 460 /* 461 * Don't double-terminate, we could be in a termination 462 * recursion due to the terminate having to sync data 463 * to disk. 464 */ 465 if ((object->flags & OBJ_DEAD) == 0) 466 vm_object_terminate(object); 467 object = temp; 468 } 469 } 470 471 /* 472 * vm_object_terminate actually destroys the specified object, freeing 473 * up all previously used resources. 474 * 475 * The object must be locked. 476 * This routine may block. 477 */ 478 void 479 vm_object_terminate(vm_object_t object) 480 { 481 vm_page_t p; 482 int s; 483 484 GIANT_REQUIRED; 485 486 /* 487 * Make sure no one uses us. 488 */ 489 vm_object_set_flag(object, OBJ_DEAD); 490 491 /* 492 * wait for the pageout daemon to be done with the object 493 */ 494 vm_object_pip_wait(object, "objtrm"); 495 496 KASSERT(!object->paging_in_progress, 497 ("vm_object_terminate: pageout in progress")); 498 499 /* 500 * Clean and free the pages, as appropriate. All references to the 501 * object are gone, so we don't need to lock it. 502 */ 503 if (object->type == OBJT_VNODE) { 504 struct vnode *vp; 505 506 /* 507 * Freeze optimized copies. 508 */ 509 vm_freeze_copyopts(object, 0, object->size); 510 511 /* 512 * Clean pages and flush buffers. 513 */ 514 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 515 516 vp = (struct vnode *) object->handle; 517 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 518 } 519 520 KASSERT(object->ref_count == 0, 521 ("vm_object_terminate: object with references, ref_count=%d", 522 object->ref_count)); 523 524 /* 525 * Now free any remaining pages. For internal objects, this also 526 * removes them from paging queues. Don't free wired pages, just 527 * remove them from the object. 528 */ 529 s = splvm(); 530 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 531 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0, 532 ("vm_object_terminate: freeing busy page %p " 533 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags)); 534 if (p->wire_count == 0) { 535 vm_page_busy(p); 536 vm_page_free(p); 537 cnt.v_pfree++; 538 } else { 539 vm_page_busy(p); 540 vm_page_remove(p); 541 } 542 } 543 splx(s); 544 545 /* 546 * Let the pager know object is dead. 547 */ 548 vm_pager_deallocate(object); 549 550 /* 551 * Remove the object from the global object list. 552 */ 553 mtx_lock(&vm_object_list_mtx); 554 TAILQ_REMOVE(&vm_object_list, object, object_list); 555 mtx_unlock(&vm_object_list_mtx); 556 557 wakeup(object); 558 559 /* 560 * Free the space for the object. 561 */ 562 zfree(obj_zone, object); 563 } 564 565 /* 566 * vm_object_page_clean 567 * 568 * Clean all dirty pages in the specified range of object. Leaves page 569 * on whatever queue it is currently on. If NOSYNC is set then do not 570 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 571 * leaving the object dirty. 572 * 573 * Odd semantics: if start == end, we clean everything. 574 * 575 * The object must be locked. 576 */ 577 578 void 579 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 580 { 581 vm_page_t p, np, tp; 582 vm_offset_t tstart, tend; 583 vm_pindex_t pi; 584 int s; 585 struct vnode *vp; 586 int runlen; 587 int maxf; 588 int chkb; 589 int maxb; 590 int i; 591 int clearobjflags; 592 int pagerflags; 593 vm_page_t maf[vm_pageout_page_count]; 594 vm_page_t mab[vm_pageout_page_count]; 595 vm_page_t ma[vm_pageout_page_count]; 596 int curgeneration; 597 598 GIANT_REQUIRED; 599 600 if (object->type != OBJT_VNODE || 601 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 602 return; 603 604 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : 0; 605 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 606 607 vp = object->handle; 608 609 vm_object_set_flag(object, OBJ_CLEANING); 610 611 tstart = start; 612 if (end == 0) { 613 tend = object->size; 614 } else { 615 tend = end; 616 } 617 618 /* 619 * Generally set CLEANCHK interlock and make the page read-only so 620 * we can then clear the object flags. 621 * 622 * However, if this is a nosync mmap then the object is likely to 623 * stay dirty so do not mess with the page and do not clear the 624 * object flags. 625 */ 626 627 clearobjflags = 1; 628 629 TAILQ_FOREACH(p, &object->memq, listq) { 630 vm_page_flag_set(p, PG_CLEANCHK); 631 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 632 clearobjflags = 0; 633 else 634 vm_page_protect(p, VM_PROT_READ); 635 } 636 637 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 638 struct vnode *vp; 639 640 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 641 if (object->type == OBJT_VNODE && 642 (vp = (struct vnode *)object->handle) != NULL) { 643 if (vp->v_flag & VOBJDIRTY) { 644 mtx_lock(&vp->v_interlock); 645 vp->v_flag &= ~VOBJDIRTY; 646 mtx_unlock(&vp->v_interlock); 647 } 648 } 649 } 650 651 rescan: 652 curgeneration = object->generation; 653 654 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 655 np = TAILQ_NEXT(p, listq); 656 657 pi = p->pindex; 658 if (((p->flags & PG_CLEANCHK) == 0) || 659 (pi < tstart) || (pi >= tend) || 660 (p->valid == 0) || 661 ((p->queue - p->pc) == PQ_CACHE)) { 662 vm_page_flag_clear(p, PG_CLEANCHK); 663 continue; 664 } 665 666 vm_page_test_dirty(p); 667 if ((p->dirty & p->valid) == 0) { 668 vm_page_flag_clear(p, PG_CLEANCHK); 669 continue; 670 } 671 672 /* 673 * If we have been asked to skip nosync pages and this is a 674 * nosync page, skip it. Note that the object flags were 675 * not cleared in this case so we do not have to set them. 676 */ 677 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 678 vm_page_flag_clear(p, PG_CLEANCHK); 679 continue; 680 } 681 682 s = splvm(); 683 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) { 684 if (object->generation != curgeneration) { 685 splx(s); 686 goto rescan; 687 } 688 } 689 690 maxf = 0; 691 for (i = 1; i < vm_pageout_page_count; i++) { 692 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 693 if ((tp->flags & PG_BUSY) || 694 (tp->flags & PG_CLEANCHK) == 0 || 695 (tp->busy != 0)) 696 break; 697 if((tp->queue - tp->pc) == PQ_CACHE) { 698 vm_page_flag_clear(tp, PG_CLEANCHK); 699 break; 700 } 701 vm_page_test_dirty(tp); 702 if ((tp->dirty & tp->valid) == 0) { 703 vm_page_flag_clear(tp, PG_CLEANCHK); 704 break; 705 } 706 maf[ i - 1 ] = tp; 707 maxf++; 708 continue; 709 } 710 break; 711 } 712 713 maxb = 0; 714 chkb = vm_pageout_page_count - maxf; 715 if (chkb) { 716 for (i = 1; i < chkb; i++) { 717 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 718 if ((tp->flags & PG_BUSY) || 719 (tp->flags & PG_CLEANCHK) == 0 || 720 (tp->busy != 0)) 721 break; 722 if((tp->queue - tp->pc) == PQ_CACHE) { 723 vm_page_flag_clear(tp, PG_CLEANCHK); 724 break; 725 } 726 vm_page_test_dirty(tp); 727 if ((tp->dirty & tp->valid) == 0) { 728 vm_page_flag_clear(tp, PG_CLEANCHK); 729 break; 730 } 731 mab[ i - 1 ] = tp; 732 maxb++; 733 continue; 734 } 735 break; 736 } 737 } 738 739 for (i = 0; i < maxb; i++) { 740 int index = (maxb - i) - 1; 741 ma[index] = mab[i]; 742 vm_page_flag_clear(ma[index], PG_CLEANCHK); 743 } 744 vm_page_flag_clear(p, PG_CLEANCHK); 745 ma[maxb] = p; 746 for (i = 0 ; i < maxf; i++) { 747 int index = (maxb + i) + 1; 748 ma[index] = maf[i]; 749 vm_page_flag_clear(ma[index], PG_CLEANCHK); 750 } 751 runlen = maxb + maxf + 1; 752 753 splx(s); 754 vm_pageout_flush(ma, runlen, pagerflags); 755 for (i = 0; i < runlen; i++) { 756 if (ma[i]->valid & ma[i]->dirty) { 757 vm_page_protect(ma[i], VM_PROT_READ); 758 vm_page_flag_set(ma[i], PG_CLEANCHK); 759 } 760 } 761 if (object->generation != curgeneration) 762 goto rescan; 763 } 764 765 #if 0 766 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 767 #endif 768 769 vm_object_clear_flag(object, OBJ_CLEANING); 770 return; 771 } 772 773 /* 774 * Same as vm_object_pmap_copy, except range checking really 775 * works, and is meant for small sections of an object. 776 * 777 * This code protects resident pages by making them read-only 778 * and is typically called on a fork or split when a page 779 * is converted to copy-on-write. 780 * 781 * NOTE: If the page is already at VM_PROT_NONE, calling 782 * vm_page_protect will have no effect. 783 */ 784 785 void 786 vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 787 { 788 vm_pindex_t idx; 789 vm_page_t p; 790 791 GIANT_REQUIRED; 792 793 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0) 794 return; 795 796 for (idx = start; idx < end; idx++) { 797 p = vm_page_lookup(object, idx); 798 if (p == NULL) 799 continue; 800 vm_page_protect(p, VM_PROT_READ); 801 } 802 } 803 804 /* 805 * vm_object_pmap_remove: 806 * 807 * Removes all physical pages in the specified 808 * object range from all physical maps. 809 * 810 * The object must *not* be locked. 811 */ 812 void 813 vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 814 { 815 vm_page_t p; 816 817 GIANT_REQUIRED; 818 if (object == NULL) 819 return; 820 TAILQ_FOREACH(p, &object->memq, listq) { 821 if (p->pindex >= start && p->pindex < end) 822 vm_page_protect(p, VM_PROT_NONE); 823 } 824 if ((start == 0) && (object->size == end)) 825 vm_object_clear_flag(object, OBJ_WRITEABLE); 826 } 827 828 /* 829 * vm_object_madvise: 830 * 831 * Implements the madvise function at the object/page level. 832 * 833 * MADV_WILLNEED (any object) 834 * 835 * Activate the specified pages if they are resident. 836 * 837 * MADV_DONTNEED (any object) 838 * 839 * Deactivate the specified pages if they are resident. 840 * 841 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 842 * OBJ_ONEMAPPING only) 843 * 844 * Deactivate and clean the specified pages if they are 845 * resident. This permits the process to reuse the pages 846 * without faulting or the kernel to reclaim the pages 847 * without I/O. 848 */ 849 void 850 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 851 { 852 vm_pindex_t end, tpindex; 853 vm_object_t tobject; 854 vm_page_t m; 855 856 GIANT_REQUIRED; 857 if (object == NULL) 858 return; 859 860 end = pindex + count; 861 862 /* 863 * Locate and adjust resident pages 864 */ 865 866 for (; pindex < end; pindex += 1) { 867 relookup: 868 tobject = object; 869 tpindex = pindex; 870 shadowlookup: 871 /* 872 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 873 * and those pages must be OBJ_ONEMAPPING. 874 */ 875 if (advise == MADV_FREE) { 876 if ((tobject->type != OBJT_DEFAULT && 877 tobject->type != OBJT_SWAP) || 878 (tobject->flags & OBJ_ONEMAPPING) == 0) { 879 continue; 880 } 881 } 882 883 m = vm_page_lookup(tobject, tpindex); 884 885 if (m == NULL) { 886 /* 887 * There may be swap even if there is no backing page 888 */ 889 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 890 swap_pager_freespace(tobject, tpindex, 1); 891 892 /* 893 * next object 894 */ 895 tobject = tobject->backing_object; 896 if (tobject == NULL) 897 continue; 898 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 899 goto shadowlookup; 900 } 901 902 /* 903 * If the page is busy or not in a normal active state, 904 * we skip it. If the page is not managed there are no 905 * page queues to mess with. Things can break if we mess 906 * with pages in any of the below states. 907 */ 908 if ( 909 m->hold_count || 910 m->wire_count || 911 (m->flags & PG_UNMANAGED) || 912 m->valid != VM_PAGE_BITS_ALL 913 ) { 914 continue; 915 } 916 917 if (vm_page_sleep_busy(m, TRUE, "madvpo")) 918 goto relookup; 919 920 if (advise == MADV_WILLNEED) { 921 vm_page_activate(m); 922 } else if (advise == MADV_DONTNEED) { 923 vm_page_dontneed(m); 924 } else if (advise == MADV_FREE) { 925 /* 926 * Mark the page clean. This will allow the page 927 * to be freed up by the system. However, such pages 928 * are often reused quickly by malloc()/free() 929 * so we do not do anything that would cause 930 * a page fault if we can help it. 931 * 932 * Specifically, we do not try to actually free 933 * the page now nor do we try to put it in the 934 * cache (which would cause a page fault on reuse). 935 * 936 * But we do make the page is freeable as we 937 * can without actually taking the step of unmapping 938 * it. 939 */ 940 pmap_clear_modify(m); 941 m->dirty = 0; 942 m->act_count = 0; 943 vm_page_dontneed(m); 944 if (tobject->type == OBJT_SWAP) 945 swap_pager_freespace(tobject, tpindex, 1); 946 } 947 } 948 } 949 950 /* 951 * vm_object_shadow: 952 * 953 * Create a new object which is backed by the 954 * specified existing object range. The source 955 * object reference is deallocated. 956 * 957 * The new object and offset into that object 958 * are returned in the source parameters. 959 */ 960 961 void 962 vm_object_shadow( 963 vm_object_t *object, /* IN/OUT */ 964 vm_ooffset_t *offset, /* IN/OUT */ 965 vm_size_t length) 966 { 967 vm_object_t source; 968 vm_object_t result; 969 970 GIANT_REQUIRED; 971 source = *object; 972 973 /* 974 * Don't create the new object if the old object isn't shared. 975 */ 976 977 if (source != NULL && 978 source->ref_count == 1 && 979 source->handle == NULL && 980 (source->type == OBJT_DEFAULT || 981 source->type == OBJT_SWAP)) 982 return; 983 984 /* 985 * Allocate a new object with the given length 986 */ 987 result = vm_object_allocate(OBJT_DEFAULT, length); 988 KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing")); 989 990 /* 991 * The new object shadows the source object, adding a reference to it. 992 * Our caller changes his reference to point to the new object, 993 * removing a reference to the source object. Net result: no change 994 * of reference count. 995 * 996 * Try to optimize the result object's page color when shadowing 997 * in order to maintain page coloring consistency in the combined 998 * shadowed object. 999 */ 1000 result->backing_object = source; 1001 if (source) { 1002 TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list); 1003 source->shadow_count++; 1004 source->generation++; 1005 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK; 1006 } 1007 1008 /* 1009 * Store the offset into the source object, and fix up the offset into 1010 * the new object. 1011 */ 1012 1013 result->backing_object_offset = *offset; 1014 1015 /* 1016 * Return the new things 1017 */ 1018 1019 *offset = 0; 1020 *object = result; 1021 } 1022 1023 #define OBSC_TEST_ALL_SHADOWED 0x0001 1024 #define OBSC_COLLAPSE_NOWAIT 0x0002 1025 #define OBSC_COLLAPSE_WAIT 0x0004 1026 1027 static __inline int 1028 vm_object_backing_scan(vm_object_t object, int op) 1029 { 1030 int s; 1031 int r = 1; 1032 vm_page_t p; 1033 vm_object_t backing_object; 1034 vm_pindex_t backing_offset_index; 1035 1036 s = splvm(); 1037 GIANT_REQUIRED; 1038 1039 backing_object = object->backing_object; 1040 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1041 1042 /* 1043 * Initial conditions 1044 */ 1045 1046 if (op & OBSC_TEST_ALL_SHADOWED) { 1047 /* 1048 * We do not want to have to test for the existence of 1049 * swap pages in the backing object. XXX but with the 1050 * new swapper this would be pretty easy to do. 1051 * 1052 * XXX what about anonymous MAP_SHARED memory that hasn't 1053 * been ZFOD faulted yet? If we do not test for this, the 1054 * shadow test may succeed! XXX 1055 */ 1056 if (backing_object->type != OBJT_DEFAULT) { 1057 splx(s); 1058 return(0); 1059 } 1060 } 1061 if (op & OBSC_COLLAPSE_WAIT) { 1062 vm_object_set_flag(backing_object, OBJ_DEAD); 1063 } 1064 1065 /* 1066 * Our scan 1067 */ 1068 1069 p = TAILQ_FIRST(&backing_object->memq); 1070 while (p) { 1071 vm_page_t next = TAILQ_NEXT(p, listq); 1072 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1073 1074 if (op & OBSC_TEST_ALL_SHADOWED) { 1075 vm_page_t pp; 1076 1077 /* 1078 * Ignore pages outside the parent object's range 1079 * and outside the parent object's mapping of the 1080 * backing object. 1081 * 1082 * note that we do not busy the backing object's 1083 * page. 1084 */ 1085 1086 if ( 1087 p->pindex < backing_offset_index || 1088 new_pindex >= object->size 1089 ) { 1090 p = next; 1091 continue; 1092 } 1093 1094 /* 1095 * See if the parent has the page or if the parent's 1096 * object pager has the page. If the parent has the 1097 * page but the page is not valid, the parent's 1098 * object pager must have the page. 1099 * 1100 * If this fails, the parent does not completely shadow 1101 * the object and we might as well give up now. 1102 */ 1103 1104 pp = vm_page_lookup(object, new_pindex); 1105 if ( 1106 (pp == NULL || pp->valid == 0) && 1107 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1108 ) { 1109 r = 0; 1110 break; 1111 } 1112 } 1113 1114 /* 1115 * Check for busy page 1116 */ 1117 1118 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1119 vm_page_t pp; 1120 1121 if (op & OBSC_COLLAPSE_NOWAIT) { 1122 if ( 1123 (p->flags & PG_BUSY) || 1124 !p->valid || 1125 p->hold_count || 1126 p->wire_count || 1127 p->busy 1128 ) { 1129 p = next; 1130 continue; 1131 } 1132 } else if (op & OBSC_COLLAPSE_WAIT) { 1133 if (vm_page_sleep_busy(p, TRUE, "vmocol")) { 1134 /* 1135 * If we slept, anything could have 1136 * happened. Since the object is 1137 * marked dead, the backing offset 1138 * should not have changed so we 1139 * just restart our scan. 1140 */ 1141 p = TAILQ_FIRST(&backing_object->memq); 1142 continue; 1143 } 1144 } 1145 1146 /* 1147 * Busy the page 1148 */ 1149 vm_page_busy(p); 1150 1151 KASSERT( 1152 p->object == backing_object, 1153 ("vm_object_qcollapse(): object mismatch") 1154 ); 1155 1156 /* 1157 * Destroy any associated swap 1158 */ 1159 if (backing_object->type == OBJT_SWAP) { 1160 swap_pager_freespace( 1161 backing_object, 1162 p->pindex, 1163 1 1164 ); 1165 } 1166 1167 if ( 1168 p->pindex < backing_offset_index || 1169 new_pindex >= object->size 1170 ) { 1171 /* 1172 * Page is out of the parent object's range, we 1173 * can simply destroy it. 1174 */ 1175 vm_page_protect(p, VM_PROT_NONE); 1176 vm_page_free(p); 1177 p = next; 1178 continue; 1179 } 1180 1181 pp = vm_page_lookup(object, new_pindex); 1182 if ( 1183 pp != NULL || 1184 vm_pager_has_page(object, new_pindex, NULL, NULL) 1185 ) { 1186 /* 1187 * page already exists in parent OR swap exists 1188 * for this location in the parent. Destroy 1189 * the original page from the backing object. 1190 * 1191 * Leave the parent's page alone 1192 */ 1193 vm_page_protect(p, VM_PROT_NONE); 1194 vm_page_free(p); 1195 p = next; 1196 continue; 1197 } 1198 1199 /* 1200 * Page does not exist in parent, rename the 1201 * page from the backing object to the main object. 1202 * 1203 * If the page was mapped to a process, it can remain 1204 * mapped through the rename. 1205 */ 1206 if ((p->queue - p->pc) == PQ_CACHE) 1207 vm_page_deactivate(p); 1208 1209 vm_page_rename(p, object, new_pindex); 1210 /* page automatically made dirty by rename */ 1211 } 1212 p = next; 1213 } 1214 splx(s); 1215 return(r); 1216 } 1217 1218 1219 /* 1220 * this version of collapse allows the operation to occur earlier and 1221 * when paging_in_progress is true for an object... This is not a complete 1222 * operation, but should plug 99.9% of the rest of the leaks. 1223 */ 1224 static void 1225 vm_object_qcollapse(vm_object_t object) 1226 { 1227 vm_object_t backing_object = object->backing_object; 1228 1229 GIANT_REQUIRED; 1230 1231 if (backing_object->ref_count != 1) 1232 return; 1233 1234 backing_object->ref_count += 2; 1235 1236 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1237 1238 backing_object->ref_count -= 2; 1239 } 1240 1241 /* 1242 * vm_object_collapse: 1243 * 1244 * Collapse an object with the object backing it. 1245 * Pages in the backing object are moved into the 1246 * parent, and the backing object is deallocated. 1247 */ 1248 void 1249 vm_object_collapse(vm_object_t object) 1250 { 1251 GIANT_REQUIRED; 1252 1253 while (TRUE) { 1254 vm_object_t backing_object; 1255 1256 /* 1257 * Verify that the conditions are right for collapse: 1258 * 1259 * The object exists and the backing object exists. 1260 */ 1261 if (object == NULL) 1262 break; 1263 1264 if ((backing_object = object->backing_object) == NULL) 1265 break; 1266 1267 /* 1268 * we check the backing object first, because it is most likely 1269 * not collapsable. 1270 */ 1271 if (backing_object->handle != NULL || 1272 (backing_object->type != OBJT_DEFAULT && 1273 backing_object->type != OBJT_SWAP) || 1274 (backing_object->flags & OBJ_DEAD) || 1275 object->handle != NULL || 1276 (object->type != OBJT_DEFAULT && 1277 object->type != OBJT_SWAP) || 1278 (object->flags & OBJ_DEAD)) { 1279 break; 1280 } 1281 1282 if ( 1283 object->paging_in_progress != 0 || 1284 backing_object->paging_in_progress != 0 1285 ) { 1286 vm_object_qcollapse(object); 1287 break; 1288 } 1289 1290 /* 1291 * We know that we can either collapse the backing object (if 1292 * the parent is the only reference to it) or (perhaps) have 1293 * the parent bypass the object if the parent happens to shadow 1294 * all the resident pages in the entire backing object. 1295 * 1296 * This is ignoring pager-backed pages such as swap pages. 1297 * vm_object_backing_scan fails the shadowing test in this 1298 * case. 1299 */ 1300 1301 if (backing_object->ref_count == 1) { 1302 /* 1303 * If there is exactly one reference to the backing 1304 * object, we can collapse it into the parent. 1305 */ 1306 1307 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1308 1309 /* 1310 * Move the pager from backing_object to object. 1311 */ 1312 1313 if (backing_object->type == OBJT_SWAP) { 1314 vm_object_pip_add(backing_object, 1); 1315 1316 /* 1317 * scrap the paging_offset junk and do a 1318 * discrete copy. This also removes major 1319 * assumptions about how the swap-pager 1320 * works from where it doesn't belong. The 1321 * new swapper is able to optimize the 1322 * destroy-source case. 1323 */ 1324 1325 vm_object_pip_add(object, 1); 1326 swap_pager_copy( 1327 backing_object, 1328 object, 1329 OFF_TO_IDX(object->backing_object_offset), TRUE); 1330 vm_object_pip_wakeup(object); 1331 1332 vm_object_pip_wakeup(backing_object); 1333 } 1334 /* 1335 * Object now shadows whatever backing_object did. 1336 * Note that the reference to 1337 * backing_object->backing_object moves from within 1338 * backing_object to within object. 1339 */ 1340 1341 TAILQ_REMOVE( 1342 &object->backing_object->shadow_head, 1343 object, 1344 shadow_list 1345 ); 1346 object->backing_object->shadow_count--; 1347 object->backing_object->generation++; 1348 if (backing_object->backing_object) { 1349 TAILQ_REMOVE( 1350 &backing_object->backing_object->shadow_head, 1351 backing_object, 1352 shadow_list 1353 ); 1354 backing_object->backing_object->shadow_count--; 1355 backing_object->backing_object->generation++; 1356 } 1357 object->backing_object = backing_object->backing_object; 1358 if (object->backing_object) { 1359 TAILQ_INSERT_TAIL( 1360 &object->backing_object->shadow_head, 1361 object, 1362 shadow_list 1363 ); 1364 object->backing_object->shadow_count++; 1365 object->backing_object->generation++; 1366 } 1367 1368 object->backing_object_offset += 1369 backing_object->backing_object_offset; 1370 1371 /* 1372 * Discard backing_object. 1373 * 1374 * Since the backing object has no pages, no pager left, 1375 * and no object references within it, all that is 1376 * necessary is to dispose of it. 1377 */ 1378 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1379 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object)); 1380 1381 TAILQ_REMOVE( 1382 &vm_object_list, 1383 backing_object, 1384 object_list 1385 ); 1386 vm_object_count--; 1387 1388 zfree(obj_zone, backing_object); 1389 1390 object_collapses++; 1391 } else { 1392 vm_object_t new_backing_object; 1393 1394 /* 1395 * If we do not entirely shadow the backing object, 1396 * there is nothing we can do so we give up. 1397 */ 1398 1399 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1400 break; 1401 } 1402 1403 /* 1404 * Make the parent shadow the next object in the 1405 * chain. Deallocating backing_object will not remove 1406 * it, since its reference count is at least 2. 1407 */ 1408 1409 TAILQ_REMOVE( 1410 &backing_object->shadow_head, 1411 object, 1412 shadow_list 1413 ); 1414 backing_object->shadow_count--; 1415 backing_object->generation++; 1416 1417 new_backing_object = backing_object->backing_object; 1418 if ((object->backing_object = new_backing_object) != NULL) { 1419 vm_object_reference(new_backing_object); 1420 TAILQ_INSERT_TAIL( 1421 &new_backing_object->shadow_head, 1422 object, 1423 shadow_list 1424 ); 1425 new_backing_object->shadow_count++; 1426 new_backing_object->generation++; 1427 object->backing_object_offset += 1428 backing_object->backing_object_offset; 1429 } 1430 1431 /* 1432 * Drop the reference count on backing_object. Since 1433 * its ref_count was at least 2, it will not vanish; 1434 * so we don't need to call vm_object_deallocate, but 1435 * we do anyway. 1436 */ 1437 vm_object_deallocate(backing_object); 1438 object_bypasses++; 1439 } 1440 1441 /* 1442 * Try again with this object's new backing object. 1443 */ 1444 } 1445 } 1446 1447 /* 1448 * vm_object_page_remove: [internal] 1449 * 1450 * Removes all physical pages in the specified 1451 * object range from the object's list of pages. 1452 * 1453 * The object must be locked. 1454 */ 1455 void 1456 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, boolean_t clean_only) 1457 { 1458 vm_page_t p, next; 1459 unsigned int size; 1460 int all; 1461 1462 GIANT_REQUIRED; 1463 1464 if (object == NULL || 1465 object->resident_page_count == 0) 1466 return; 1467 1468 all = ((end == 0) && (start == 0)); 1469 1470 /* 1471 * Since physically-backed objects do not use managed pages, we can't 1472 * remove pages from the object (we must instead remove the page 1473 * references, and then destroy the object). 1474 */ 1475 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object")); 1476 1477 vm_object_pip_add(object, 1); 1478 again: 1479 size = end - start; 1480 if (all || size > object->resident_page_count / 4) { 1481 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 1482 next = TAILQ_NEXT(p, listq); 1483 if (all || ((start <= p->pindex) && (p->pindex < end))) { 1484 if (p->wire_count != 0) { 1485 vm_page_protect(p, VM_PROT_NONE); 1486 if (!clean_only) 1487 p->valid = 0; 1488 continue; 1489 } 1490 1491 /* 1492 * The busy flags are only cleared at 1493 * interrupt -- minimize the spl transitions 1494 */ 1495 1496 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1497 goto again; 1498 1499 if (clean_only && p->valid) { 1500 vm_page_test_dirty(p); 1501 if (p->valid & p->dirty) 1502 continue; 1503 } 1504 1505 vm_page_busy(p); 1506 vm_page_protect(p, VM_PROT_NONE); 1507 vm_page_free(p); 1508 } 1509 } 1510 } else { 1511 while (size > 0) { 1512 if ((p = vm_page_lookup(object, start)) != 0) { 1513 1514 if (p->wire_count != 0) { 1515 vm_page_protect(p, VM_PROT_NONE); 1516 if (!clean_only) 1517 p->valid = 0; 1518 start += 1; 1519 size -= 1; 1520 continue; 1521 } 1522 1523 /* 1524 * The busy flags are only cleared at 1525 * interrupt -- minimize the spl transitions 1526 */ 1527 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1528 goto again; 1529 1530 if (clean_only && p->valid) { 1531 vm_page_test_dirty(p); 1532 if (p->valid & p->dirty) { 1533 start += 1; 1534 size -= 1; 1535 continue; 1536 } 1537 } 1538 1539 vm_page_busy(p); 1540 vm_page_protect(p, VM_PROT_NONE); 1541 vm_page_free(p); 1542 } 1543 start += 1; 1544 size -= 1; 1545 } 1546 } 1547 vm_object_pip_wakeup(object); 1548 } 1549 1550 /* 1551 * Routine: vm_object_coalesce 1552 * Function: Coalesces two objects backing up adjoining 1553 * regions of memory into a single object. 1554 * 1555 * returns TRUE if objects were combined. 1556 * 1557 * NOTE: Only works at the moment if the second object is NULL - 1558 * if it's not, which object do we lock first? 1559 * 1560 * Parameters: 1561 * prev_object First object to coalesce 1562 * prev_offset Offset into prev_object 1563 * next_object Second object into coalesce 1564 * next_offset Offset into next_object 1565 * 1566 * prev_size Size of reference to prev_object 1567 * next_size Size of reference to next_object 1568 * 1569 * Conditions: 1570 * The object must *not* be locked. 1571 */ 1572 boolean_t 1573 vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, vm_size_t prev_size, vm_size_t next_size) 1574 { 1575 vm_pindex_t next_pindex; 1576 1577 GIANT_REQUIRED; 1578 1579 if (prev_object == NULL) { 1580 return (TRUE); 1581 } 1582 1583 if (prev_object->type != OBJT_DEFAULT && 1584 prev_object->type != OBJT_SWAP) { 1585 return (FALSE); 1586 } 1587 1588 /* 1589 * Try to collapse the object first 1590 */ 1591 vm_object_collapse(prev_object); 1592 1593 /* 1594 * Can't coalesce if: . more than one reference . paged out . shadows 1595 * another object . has a copy elsewhere (any of which mean that the 1596 * pages not mapped to prev_entry may be in use anyway) 1597 */ 1598 1599 if (prev_object->backing_object != NULL) { 1600 return (FALSE); 1601 } 1602 1603 prev_size >>= PAGE_SHIFT; 1604 next_size >>= PAGE_SHIFT; 1605 next_pindex = prev_pindex + prev_size; 1606 1607 if ((prev_object->ref_count > 1) && 1608 (prev_object->size != next_pindex)) { 1609 return (FALSE); 1610 } 1611 1612 /* 1613 * Remove any pages that may still be in the object from a previous 1614 * deallocation. 1615 */ 1616 if (next_pindex < prev_object->size) { 1617 vm_object_page_remove(prev_object, 1618 next_pindex, 1619 next_pindex + next_size, FALSE); 1620 if (prev_object->type == OBJT_SWAP) 1621 swap_pager_freespace(prev_object, 1622 next_pindex, next_size); 1623 } 1624 1625 /* 1626 * Extend the object if necessary. 1627 */ 1628 if (next_pindex + next_size > prev_object->size) 1629 prev_object->size = next_pindex + next_size; 1630 1631 return (TRUE); 1632 } 1633 1634 void 1635 vm_object_set_writeable_dirty(vm_object_t object) 1636 { 1637 struct vnode *vp; 1638 1639 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1640 if (object->type == OBJT_VNODE && 1641 (vp = (struct vnode *)object->handle) != NULL) { 1642 if ((vp->v_flag & VOBJDIRTY) == 0) { 1643 mtx_lock(&vp->v_interlock); 1644 vp->v_flag |= VOBJDIRTY; 1645 mtx_unlock(&vp->v_interlock); 1646 } 1647 } 1648 } 1649 1650 #include "opt_ddb.h" 1651 #ifdef DDB 1652 #include <sys/kernel.h> 1653 1654 #include <sys/cons.h> 1655 1656 #include <ddb/ddb.h> 1657 1658 static int 1659 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1660 { 1661 vm_map_t tmpm; 1662 vm_map_entry_t tmpe; 1663 vm_object_t obj; 1664 int entcount; 1665 1666 if (map == 0) 1667 return 0; 1668 1669 if (entry == 0) { 1670 tmpe = map->header.next; 1671 entcount = map->nentries; 1672 while (entcount-- && (tmpe != &map->header)) { 1673 if( _vm_object_in_map(map, object, tmpe)) { 1674 return 1; 1675 } 1676 tmpe = tmpe->next; 1677 } 1678 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1679 tmpm = entry->object.sub_map; 1680 tmpe = tmpm->header.next; 1681 entcount = tmpm->nentries; 1682 while (entcount-- && tmpe != &tmpm->header) { 1683 if( _vm_object_in_map(tmpm, object, tmpe)) { 1684 return 1; 1685 } 1686 tmpe = tmpe->next; 1687 } 1688 } else if ((obj = entry->object.vm_object) != NULL) { 1689 for (; obj; obj = obj->backing_object) 1690 if( obj == object) { 1691 return 1; 1692 } 1693 } 1694 return 0; 1695 } 1696 1697 static int 1698 vm_object_in_map(vm_object_t object) 1699 { 1700 struct proc *p; 1701 1702 /* sx_slock(&allproc_lock); */ 1703 LIST_FOREACH(p, &allproc, p_list) { 1704 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1705 continue; 1706 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 1707 /* sx_sunlock(&allproc_lock); */ 1708 return 1; 1709 } 1710 } 1711 /* sx_sunlock(&allproc_lock); */ 1712 if( _vm_object_in_map( kernel_map, object, 0)) 1713 return 1; 1714 if( _vm_object_in_map( kmem_map, object, 0)) 1715 return 1; 1716 if( _vm_object_in_map( pager_map, object, 0)) 1717 return 1; 1718 if( _vm_object_in_map( buffer_map, object, 0)) 1719 return 1; 1720 return 0; 1721 } 1722 1723 DB_SHOW_COMMAND(vmochk, vm_object_check) 1724 { 1725 vm_object_t object; 1726 1727 /* 1728 * make sure that internal objs are in a map somewhere 1729 * and none have zero ref counts. 1730 */ 1731 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1732 if (object->handle == NULL && 1733 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1734 if (object->ref_count == 0) { 1735 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1736 (long)object->size); 1737 } 1738 if (!vm_object_in_map(object)) { 1739 db_printf( 1740 "vmochk: internal obj is not in a map: " 1741 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1742 object->ref_count, (u_long)object->size, 1743 (u_long)object->size, 1744 (void *)object->backing_object); 1745 } 1746 } 1747 } 1748 } 1749 1750 /* 1751 * vm_object_print: [ debug ] 1752 */ 1753 DB_SHOW_COMMAND(object, vm_object_print_static) 1754 { 1755 /* XXX convert args. */ 1756 vm_object_t object = (vm_object_t)addr; 1757 boolean_t full = have_addr; 1758 1759 vm_page_t p; 1760 1761 /* XXX count is an (unused) arg. Avoid shadowing it. */ 1762 #define count was_count 1763 1764 int count; 1765 1766 if (object == NULL) 1767 return; 1768 1769 db_iprintf( 1770 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n", 1771 object, (int)object->type, (u_long)object->size, 1772 object->resident_page_count, object->ref_count, object->flags); 1773 /* 1774 * XXX no %qd in kernel. Truncate object->backing_object_offset. 1775 */ 1776 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n", 1777 object->shadow_count, 1778 object->backing_object ? object->backing_object->ref_count : 0, 1779 object->backing_object, (long)object->backing_object_offset); 1780 1781 if (!full) 1782 return; 1783 1784 db_indent += 2; 1785 count = 0; 1786 TAILQ_FOREACH(p, &object->memq, listq) { 1787 if (count == 0) 1788 db_iprintf("memory:="); 1789 else if (count == 6) { 1790 db_printf("\n"); 1791 db_iprintf(" ..."); 1792 count = 0; 1793 } else 1794 db_printf(","); 1795 count++; 1796 1797 db_printf("(off=0x%lx,page=0x%lx)", 1798 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p)); 1799 } 1800 if (count != 0) 1801 db_printf("\n"); 1802 db_indent -= 2; 1803 } 1804 1805 /* XXX. */ 1806 #undef count 1807 1808 /* XXX need this non-static entry for calling from vm_map_print. */ 1809 void 1810 vm_object_print( 1811 /* db_expr_t */ long addr, 1812 boolean_t have_addr, 1813 /* db_expr_t */ long count, 1814 char *modif) 1815 { 1816 vm_object_print_static(addr, have_addr, count, modif); 1817 } 1818 1819 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 1820 { 1821 vm_object_t object; 1822 int nl = 0; 1823 int c; 1824 1825 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1826 vm_pindex_t idx, fidx; 1827 vm_pindex_t osize; 1828 vm_offset_t pa = -1, padiff; 1829 int rcount; 1830 vm_page_t m; 1831 1832 db_printf("new object: %p\n", (void *)object); 1833 if ( nl > 18) { 1834 c = cngetc(); 1835 if (c != ' ') 1836 return; 1837 nl = 0; 1838 } 1839 nl++; 1840 rcount = 0; 1841 fidx = 0; 1842 osize = object->size; 1843 if (osize > 128) 1844 osize = 128; 1845 for (idx = 0; idx < osize; idx++) { 1846 m = vm_page_lookup(object, idx); 1847 if (m == NULL) { 1848 if (rcount) { 1849 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1850 (long)fidx, rcount, (long)pa); 1851 if ( nl > 18) { 1852 c = cngetc(); 1853 if (c != ' ') 1854 return; 1855 nl = 0; 1856 } 1857 nl++; 1858 rcount = 0; 1859 } 1860 continue; 1861 } 1862 1863 1864 if (rcount && 1865 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 1866 ++rcount; 1867 continue; 1868 } 1869 if (rcount) { 1870 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 1871 padiff >>= PAGE_SHIFT; 1872 padiff &= PQ_L2_MASK; 1873 if (padiff == 0) { 1874 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 1875 ++rcount; 1876 continue; 1877 } 1878 db_printf(" index(%ld)run(%d)pa(0x%lx)", 1879 (long)fidx, rcount, (long)pa); 1880 db_printf("pd(%ld)\n", (long)padiff); 1881 if ( nl > 18) { 1882 c = cngetc(); 1883 if (c != ' ') 1884 return; 1885 nl = 0; 1886 } 1887 nl++; 1888 } 1889 fidx = idx; 1890 pa = VM_PAGE_TO_PHYS(m); 1891 rcount = 1; 1892 } 1893 if (rcount) { 1894 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1895 (long)fidx, rcount, (long)pa); 1896 if ( nl > 18) { 1897 c = cngetc(); 1898 if (c != ' ') 1899 return; 1900 nl = 0; 1901 } 1902 nl++; 1903 } 1904 } 1905 } 1906 #endif /* DDB */ 1907