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