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: src/sys/vm/vm_object.c,v 1.171.2.8 2003/05/26 19:17:56 alc Exp $ 65 */ 66 67 /* 68 * Virtual memory object module. 69 */ 70 71 #include <sys/param.h> 72 #include <sys/systm.h> 73 #include <sys/proc.h> /* for curproc, pageproc */ 74 #include <sys/vnode.h> 75 #include <sys/vmmeter.h> 76 #include <sys/mman.h> 77 #include <sys/mount.h> 78 #include <sys/kernel.h> 79 #include <sys/sysctl.h> 80 81 #include <vm/vm.h> 82 #include <vm/vm_param.h> 83 #include <vm/pmap.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_object.h> 86 #include <vm/vm_page.h> 87 #include <vm/vm_pageout.h> 88 #include <vm/vm_pager.h> 89 #include <vm/swap_pager.h> 90 #include <vm/vm_kern.h> 91 #include <vm/vm_extern.h> 92 #include <vm/vm_zone.h> 93 94 #define EASY_SCAN_FACTOR 8 95 96 #define MSYNC_FLUSH_HARDSEQ 0x01 97 #define MSYNC_FLUSH_SOFTSEQ 0x02 98 99 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 100 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, 101 CTLFLAG_RW, &msync_flush_flags, 0, ""); 102 103 static void vm_object_qcollapse (vm_object_t object); 104 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 105 106 /* 107 * Virtual memory objects maintain the actual data 108 * associated with allocated virtual memory. A given 109 * page of memory exists within exactly one object. 110 * 111 * An object is only deallocated when all "references" 112 * are given up. Only one "reference" to a given 113 * region of an object should be writeable. 114 * 115 * Associated with each object is a list of all resident 116 * memory pages belonging to that object; this list is 117 * maintained by the "vm_page" module, and locked by the object's 118 * lock. 119 * 120 * Each object also records a "pager" routine which is 121 * used to retrieve (and store) pages to the proper backing 122 * storage. In addition, objects may be backed by other 123 * objects from which they were virtual-copied. 124 * 125 * The only items within the object structure which are 126 * modified after time of creation are: 127 * reference count locked by object's lock 128 * pager routine locked by object's lock 129 * 130 */ 131 132 struct object_q vm_object_list; 133 #ifndef NULL_SIMPLELOCKS 134 static struct simplelock vm_object_list_lock; 135 #endif 136 static long vm_object_count; /* count of all objects */ 137 vm_object_t kernel_object; 138 vm_object_t kmem_object; 139 static struct vm_object kernel_object_store; 140 static struct vm_object kmem_object_store; 141 extern int vm_pageout_page_count; 142 143 static long object_collapses; 144 static long object_bypasses; 145 static int next_index; 146 static vm_zone_t obj_zone; 147 static struct vm_zone obj_zone_store; 148 static int object_hash_rand; 149 #define VM_OBJECTS_INIT 256 150 static struct vm_object vm_objects_init[VM_OBJECTS_INIT]; 151 152 void 153 _vm_object_allocate(type, size, object) 154 objtype_t type; 155 vm_size_t size; 156 vm_object_t object; 157 { 158 int incr; 159 TAILQ_INIT(&object->memq); 160 LIST_INIT(&object->shadow_head); 161 162 object->type = type; 163 object->size = size; 164 object->ref_count = 1; 165 object->flags = 0; 166 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 167 vm_object_set_flag(object, OBJ_ONEMAPPING); 168 object->paging_in_progress = 0; 169 object->resident_page_count = 0; 170 object->shadow_count = 0; 171 object->pg_color = next_index; 172 if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 173 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 174 else 175 incr = size; 176 next_index = (next_index + incr) & PQ_L2_MASK; 177 object->handle = NULL; 178 object->backing_object = NULL; 179 object->backing_object_offset = (vm_ooffset_t) 0; 180 /* 181 * Try to generate a number that will spread objects out in the 182 * hash table. We 'wipe' new objects across the hash in 128 page 183 * increments plus 1 more to offset it a little more by the time 184 * it wraps around. 185 */ 186 object->hash_rand = object_hash_rand - 129; 187 188 object->generation++; 189 190 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 191 vm_object_count++; 192 object_hash_rand = object->hash_rand; 193 } 194 195 /* 196 * vm_object_init: 197 * 198 * Initialize the VM objects module. 199 */ 200 void 201 vm_object_init() 202 { 203 TAILQ_INIT(&vm_object_list); 204 simple_lock_init(&vm_object_list_lock); 205 vm_object_count = 0; 206 207 kernel_object = &kernel_object_store; 208 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 209 kernel_object); 210 211 kmem_object = &kmem_object_store; 212 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 213 kmem_object); 214 215 obj_zone = &obj_zone_store; 216 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object), 217 vm_objects_init, VM_OBJECTS_INIT); 218 } 219 220 void 221 vm_object_init2() { 222 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1); 223 } 224 225 /* 226 * vm_object_allocate: 227 * 228 * Returns a new object with the given size. 229 */ 230 231 vm_object_t 232 vm_object_allocate(type, size) 233 objtype_t type; 234 vm_size_t size; 235 { 236 vm_object_t result; 237 238 result = (vm_object_t) zalloc(obj_zone); 239 240 _vm_object_allocate(type, size, result); 241 242 return (result); 243 } 244 245 246 /* 247 * vm_object_reference: 248 * 249 * Gets another reference to the given object. 250 */ 251 void 252 vm_object_reference(object) 253 vm_object_t object; 254 { 255 if (object == NULL) 256 return; 257 258 #if 0 259 /* object can be re-referenced during final cleaning */ 260 KASSERT(!(object->flags & OBJ_DEAD), 261 ("vm_object_reference: attempting to reference dead obj")); 262 #endif 263 264 object->ref_count++; 265 if (object->type == OBJT_VNODE) { 266 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curproc)) { 267 printf("vm_object_reference: delay in getting object\n"); 268 } 269 } 270 } 271 272 void 273 vm_object_vndeallocate(object) 274 vm_object_t object; 275 { 276 struct vnode *vp = (struct vnode *) object->handle; 277 278 KASSERT(object->type == OBJT_VNODE, 279 ("vm_object_vndeallocate: not a vnode object")); 280 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 281 #ifdef INVARIANTS 282 if (object->ref_count == 0) { 283 vprint("vm_object_vndeallocate", vp); 284 panic("vm_object_vndeallocate: bad object reference count"); 285 } 286 #endif 287 288 object->ref_count--; 289 if (object->ref_count == 0) { 290 vp->v_flag &= ~VTEXT; 291 vm_object_clear_flag(object, OBJ_OPT); 292 } 293 vrele(vp); 294 } 295 296 /* 297 * vm_object_deallocate: 298 * 299 * Release a reference to the specified object, 300 * gained either through a vm_object_allocate 301 * or a vm_object_reference call. When all references 302 * are gone, storage associated with this object 303 * may be relinquished. 304 * 305 * No object may be locked. 306 */ 307 void 308 vm_object_deallocate(object) 309 vm_object_t object; 310 { 311 vm_object_t temp; 312 313 while (object != NULL) { 314 315 if (object->type == OBJT_VNODE) { 316 vm_object_vndeallocate(object); 317 return; 318 } 319 320 if (object->ref_count == 0) { 321 panic("vm_object_deallocate: object deallocated too many times: %d", object->type); 322 } else if (object->ref_count > 2) { 323 object->ref_count--; 324 return; 325 } 326 327 /* 328 * Here on ref_count of one or two, which are special cases for 329 * objects. 330 */ 331 if ((object->ref_count == 2) && (object->shadow_count == 0)) { 332 vm_object_set_flag(object, OBJ_ONEMAPPING); 333 object->ref_count--; 334 return; 335 } else if ((object->ref_count == 2) && (object->shadow_count == 1)) { 336 object->ref_count--; 337 if ((object->handle == NULL) && 338 (object->type == OBJT_DEFAULT || 339 object->type == OBJT_SWAP)) { 340 vm_object_t robject; 341 342 robject = LIST_FIRST(&object->shadow_head); 343 KASSERT(robject != NULL, 344 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 345 object->ref_count, 346 object->shadow_count)); 347 if ((robject->handle == NULL) && 348 (robject->type == OBJT_DEFAULT || 349 robject->type == OBJT_SWAP)) { 350 351 robject->ref_count++; 352 353 while ( 354 robject->paging_in_progress || 355 object->paging_in_progress 356 ) { 357 vm_object_pip_sleep(robject, "objde1"); 358 vm_object_pip_sleep(object, "objde2"); 359 } 360 361 if (robject->ref_count == 1) { 362 robject->ref_count--; 363 object = robject; 364 goto doterm; 365 } 366 367 object = robject; 368 vm_object_collapse(object); 369 continue; 370 } 371 } 372 373 return; 374 375 } else { 376 object->ref_count--; 377 if (object->ref_count != 0) 378 return; 379 } 380 381 doterm: 382 383 temp = object->backing_object; 384 if (temp) { 385 LIST_REMOVE(object, shadow_list); 386 temp->shadow_count--; 387 if (temp->ref_count == 0) 388 vm_object_clear_flag(temp, OBJ_OPT); 389 temp->generation++; 390 object->backing_object = NULL; 391 } 392 393 /* 394 * Don't double-terminate, we could be in a termination 395 * recursion due to the terminate having to sync data 396 * to disk. 397 */ 398 if ((object->flags & OBJ_DEAD) == 0) 399 vm_object_terminate(object); 400 object = temp; 401 } 402 } 403 404 /* 405 * vm_object_terminate actually destroys the specified object, freeing 406 * up all previously used resources. 407 * 408 * The object must be locked. 409 * This routine may block. 410 */ 411 void 412 vm_object_terminate(object) 413 vm_object_t object; 414 { 415 vm_page_t p; 416 int s; 417 418 /* 419 * Make sure no one uses us. 420 */ 421 vm_object_set_flag(object, OBJ_DEAD); 422 423 /* 424 * wait for the pageout daemon to be done with the object 425 */ 426 vm_object_pip_wait(object, "objtrm"); 427 428 KASSERT(!object->paging_in_progress, 429 ("vm_object_terminate: pageout in progress")); 430 431 /* 432 * Clean and free the pages, as appropriate. All references to the 433 * object are gone, so we don't need to lock it. 434 */ 435 if (object->type == OBJT_VNODE) { 436 struct vnode *vp; 437 438 /* 439 * Freeze optimized copies. 440 */ 441 vm_freeze_copyopts(object, 0, object->size); 442 443 /* 444 * Clean pages and flush buffers. 445 */ 446 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 447 448 vp = (struct vnode *) object->handle; 449 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 450 } 451 452 /* 453 * Wait for any I/O to complete, after which there had better not 454 * be any references left on the object. 455 */ 456 vm_object_pip_wait(object, "objtrm"); 457 458 if (object->ref_count != 0) 459 panic("vm_object_terminate: object with references, ref_count=%d", object->ref_count); 460 461 /* 462 * Now free any remaining pages. For internal objects, this also 463 * removes them from paging queues. Don't free wired pages, just 464 * remove them from the object. 465 */ 466 s = splvm(); 467 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 468 if (p->busy || (p->flags & PG_BUSY)) 469 panic("vm_object_terminate: freeing busy page %p\n", p); 470 if (p->wire_count == 0) { 471 vm_page_busy(p); 472 vm_page_free(p); 473 cnt.v_pfree++; 474 } else { 475 vm_page_busy(p); 476 vm_page_remove(p); 477 } 478 } 479 splx(s); 480 481 /* 482 * Let the pager know object is dead. 483 */ 484 vm_pager_deallocate(object); 485 486 /* 487 * Remove the object from the global object list. 488 */ 489 simple_lock(&vm_object_list_lock); 490 TAILQ_REMOVE(&vm_object_list, object, object_list); 491 simple_unlock(&vm_object_list_lock); 492 493 wakeup(object); 494 495 /* 496 * Free the space for the object. 497 */ 498 zfree(obj_zone, object); 499 } 500 501 /* 502 * vm_object_page_clean 503 * 504 * Clean all dirty pages in the specified range of object. Leaves page 505 * on whatever queue it is currently on. If NOSYNC is set then do not 506 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 507 * leaving the object dirty. 508 * 509 * When stuffing pages asynchronously, allow clustering. XXX we need a 510 * synchronous clustering mode implementation. 511 * 512 * Odd semantics: if start == end, we clean everything. 513 * 514 * The object must be locked. 515 */ 516 517 void 518 vm_object_page_clean(object, start, end, flags) 519 vm_object_t object; 520 vm_pindex_t start; 521 vm_pindex_t end; 522 int flags; 523 { 524 vm_page_t p, np; 525 vm_offset_t tstart, tend; 526 vm_pindex_t pi; 527 struct vnode *vp; 528 int clearobjflags; 529 int pagerflags; 530 int curgeneration; 531 532 if (object->type != OBJT_VNODE || 533 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 534 return; 535 536 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 537 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 538 539 vp = object->handle; 540 541 vm_object_set_flag(object, OBJ_CLEANING); 542 543 /* 544 * Handle 'entire object' case 545 */ 546 tstart = start; 547 if (end == 0) { 548 tend = object->size; 549 } else { 550 tend = end; 551 } 552 553 /* 554 * If the caller is smart and only msync()s a range he knows is 555 * dirty, we may be able to avoid an object scan. This results in 556 * a phenominal improvement in performance. We cannot do this 557 * as a matter of course because the object may be huge - e.g. 558 * the size might be in the gigabytes or terrabytes. 559 */ 560 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 561 vm_offset_t tscan; 562 int scanlimit; 563 int scanreset; 564 565 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 566 if (scanreset < 16) 567 scanreset = 16; 568 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 569 570 scanlimit = scanreset; 571 tscan = tstart; 572 while (tscan < tend) { 573 curgeneration = object->generation; 574 p = vm_page_lookup(object, tscan); 575 if (p == NULL || p->valid == 0 || 576 (p->queue - p->pc) == PQ_CACHE) { 577 if (--scanlimit == 0) 578 break; 579 ++tscan; 580 continue; 581 } 582 vm_page_test_dirty(p); 583 if ((p->dirty & p->valid) == 0) { 584 if (--scanlimit == 0) 585 break; 586 ++tscan; 587 continue; 588 } 589 /* 590 * If we have been asked to skip nosync pages and 591 * this is a nosync page, we can't continue. 592 */ 593 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 594 if (--scanlimit == 0) 595 break; 596 ++tscan; 597 continue; 598 } 599 scanlimit = scanreset; 600 601 /* 602 * This returns 0 if it was unable to busy the first 603 * page (i.e. had to sleep). 604 */ 605 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 606 } 607 608 /* 609 * If everything was dirty and we flushed it successfully, 610 * and the requested range is not the entire object, we 611 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 612 * return immediately. 613 */ 614 if (tscan >= tend && (tstart || tend < object->size)) { 615 vm_object_clear_flag(object, OBJ_CLEANING); 616 return; 617 } 618 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 619 } 620 621 /* 622 * Generally set CLEANCHK interlock and make the page read-only so 623 * we can then clear the object flags. 624 * 625 * However, if this is a nosync mmap then the object is likely to 626 * stay dirty so do not mess with the page and do not clear the 627 * object flags. 628 */ 629 630 clearobjflags = 1; 631 632 for(p = TAILQ_FIRST(&object->memq); p; p = TAILQ_NEXT(p, listq)) { 633 vm_page_flag_set(p, PG_CLEANCHK); 634 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 635 clearobjflags = 0; 636 else 637 vm_page_protect(p, VM_PROT_READ); 638 } 639 640 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 641 struct vnode *vp; 642 643 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 644 if (object->type == OBJT_VNODE && 645 (vp = (struct vnode *)object->handle) != NULL) { 646 if (vp->v_flag & VOBJDIRTY) { 647 simple_lock(&vp->v_interlock); 648 vp->v_flag &= ~VOBJDIRTY; 649 simple_unlock(&vp->v_interlock); 650 } 651 } 652 } 653 654 rescan: 655 curgeneration = object->generation; 656 657 for(p = TAILQ_FIRST(&object->memq); p; p = np) { 658 int n; 659 660 np = TAILQ_NEXT(p, listq); 661 662 again: 663 pi = p->pindex; 664 if (((p->flags & PG_CLEANCHK) == 0) || 665 (pi < tstart) || (pi >= tend) || 666 (p->valid == 0) || 667 ((p->queue - p->pc) == PQ_CACHE)) { 668 vm_page_flag_clear(p, PG_CLEANCHK); 669 continue; 670 } 671 672 vm_page_test_dirty(p); 673 if ((p->dirty & p->valid) == 0) { 674 vm_page_flag_clear(p, PG_CLEANCHK); 675 continue; 676 } 677 678 /* 679 * If we have been asked to skip nosync pages and this is a 680 * nosync page, skip it. Note that the object flags were 681 * not cleared in this case so we do not have to set them. 682 */ 683 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 684 vm_page_flag_clear(p, PG_CLEANCHK); 685 continue; 686 } 687 688 n = vm_object_page_collect_flush(object, p, 689 curgeneration, pagerflags); 690 if (n == 0) 691 goto rescan; 692 if (object->generation != curgeneration) 693 goto rescan; 694 695 /* 696 * Try to optimize the next page. If we can't we pick up 697 * our (random) scan where we left off. 698 */ 699 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 700 if ((p = vm_page_lookup(object, pi + n)) != NULL) 701 goto again; 702 } 703 } 704 705 #if 0 706 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 707 #endif 708 709 vm_object_clear_flag(object, OBJ_CLEANING); 710 return; 711 } 712 713 static int 714 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 715 { 716 int runlen; 717 int s; 718 int maxf; 719 int chkb; 720 int maxb; 721 int i; 722 vm_pindex_t pi; 723 vm_page_t maf[vm_pageout_page_count]; 724 vm_page_t mab[vm_pageout_page_count]; 725 vm_page_t ma[vm_pageout_page_count]; 726 727 s = splvm(); 728 pi = p->pindex; 729 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) { 730 if (object->generation != curgeneration) { 731 splx(s); 732 return(0); 733 } 734 } 735 736 maxf = 0; 737 for(i = 1; i < vm_pageout_page_count; i++) { 738 vm_page_t tp; 739 740 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 741 if ((tp->flags & PG_BUSY) || 742 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 743 (tp->flags & PG_CLEANCHK) == 0) || 744 (tp->busy != 0)) 745 break; 746 if((tp->queue - tp->pc) == PQ_CACHE) { 747 vm_page_flag_clear(tp, PG_CLEANCHK); 748 break; 749 } 750 vm_page_test_dirty(tp); 751 if ((tp->dirty & tp->valid) == 0) { 752 vm_page_flag_clear(tp, PG_CLEANCHK); 753 break; 754 } 755 maf[ i - 1 ] = tp; 756 maxf++; 757 continue; 758 } 759 break; 760 } 761 762 maxb = 0; 763 chkb = vm_pageout_page_count - maxf; 764 if (chkb) { 765 for(i = 1; i < chkb;i++) { 766 vm_page_t tp; 767 768 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 769 if ((tp->flags & PG_BUSY) || 770 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 771 (tp->flags & PG_CLEANCHK) == 0) || 772 (tp->busy != 0)) 773 break; 774 if((tp->queue - tp->pc) == PQ_CACHE) { 775 vm_page_flag_clear(tp, PG_CLEANCHK); 776 break; 777 } 778 vm_page_test_dirty(tp); 779 if ((tp->dirty & tp->valid) == 0) { 780 vm_page_flag_clear(tp, PG_CLEANCHK); 781 break; 782 } 783 mab[ i - 1 ] = tp; 784 maxb++; 785 continue; 786 } 787 break; 788 } 789 } 790 791 for(i = 0; i < maxb; i++) { 792 int index = (maxb - i) - 1; 793 ma[index] = mab[i]; 794 vm_page_flag_clear(ma[index], PG_CLEANCHK); 795 } 796 vm_page_flag_clear(p, PG_CLEANCHK); 797 ma[maxb] = p; 798 for(i = 0; i < maxf; i++) { 799 int index = (maxb + i) + 1; 800 ma[index] = maf[i]; 801 vm_page_flag_clear(ma[index], PG_CLEANCHK); 802 } 803 runlen = maxb + maxf + 1; 804 805 splx(s); 806 vm_pageout_flush(ma, runlen, pagerflags); 807 for (i = 0; i < runlen; i++) { 808 if (ma[i]->valid & ma[i]->dirty) { 809 vm_page_protect(ma[i], VM_PROT_READ); 810 vm_page_flag_set(ma[i], PG_CLEANCHK); 811 812 /* 813 * maxf will end up being the actual number of pages 814 * we wrote out contiguously, non-inclusive of the 815 * first page. We do not count look-behind pages. 816 */ 817 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 818 maxf = i - maxb - 1; 819 } 820 } 821 return(maxf + 1); 822 } 823 824 #ifdef not_used 825 /* XXX I cannot tell if this should be an exported symbol */ 826 /* 827 * vm_object_deactivate_pages 828 * 829 * Deactivate all pages in the specified object. (Keep its pages 830 * in memory even though it is no longer referenced.) 831 * 832 * The object must be locked. 833 */ 834 static void 835 vm_object_deactivate_pages(object) 836 vm_object_t object; 837 { 838 vm_page_t p, next; 839 840 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 841 next = TAILQ_NEXT(p, listq); 842 vm_page_deactivate(p); 843 } 844 } 845 #endif 846 847 /* 848 * Same as vm_object_pmap_copy, except range checking really 849 * works, and is meant for small sections of an object. 850 * 851 * This code protects resident pages by making them read-only 852 * and is typically called on a fork or split when a page 853 * is converted to copy-on-write. 854 * 855 * NOTE: If the page is already at VM_PROT_NONE, calling 856 * vm_page_protect will have no effect. 857 */ 858 859 void 860 vm_object_pmap_copy_1(object, start, end) 861 vm_object_t object; 862 vm_pindex_t start; 863 vm_pindex_t end; 864 { 865 vm_pindex_t idx; 866 vm_page_t p; 867 868 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0) 869 return; 870 871 for (idx = start; idx < end; idx++) { 872 p = vm_page_lookup(object, idx); 873 if (p == NULL) 874 continue; 875 vm_page_protect(p, VM_PROT_READ); 876 } 877 } 878 879 /* 880 * vm_object_pmap_remove: 881 * 882 * Removes all physical pages in the specified 883 * object range from all physical maps. 884 * 885 * The object must *not* be locked. 886 */ 887 void 888 vm_object_pmap_remove(object, start, end) 889 vm_object_t object; 890 vm_pindex_t start; 891 vm_pindex_t end; 892 { 893 vm_page_t p; 894 895 if (object == NULL) 896 return; 897 for (p = TAILQ_FIRST(&object->memq); 898 p != NULL; 899 p = TAILQ_NEXT(p, listq)) { 900 if (p->pindex >= start && p->pindex < end) 901 vm_page_protect(p, VM_PROT_NONE); 902 } 903 if ((start == 0) && (object->size == end)) 904 vm_object_clear_flag(object, OBJ_WRITEABLE); 905 } 906 907 /* 908 * vm_object_madvise: 909 * 910 * Implements the madvise function at the object/page level. 911 * 912 * MADV_WILLNEED (any object) 913 * 914 * Activate the specified pages if they are resident. 915 * 916 * MADV_DONTNEED (any object) 917 * 918 * Deactivate the specified pages if they are resident. 919 * 920 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 921 * OBJ_ONEMAPPING only) 922 * 923 * Deactivate and clean the specified pages if they are 924 * resident. This permits the process to reuse the pages 925 * without faulting or the kernel to reclaim the pages 926 * without I/O. 927 */ 928 void 929 vm_object_madvise(object, pindex, count, advise) 930 vm_object_t object; 931 vm_pindex_t pindex; 932 int count; 933 int advise; 934 { 935 vm_pindex_t end, tpindex; 936 vm_object_t tobject; 937 vm_page_t m; 938 939 if (object == NULL) 940 return; 941 942 end = pindex + count; 943 944 /* 945 * Locate and adjust resident pages 946 */ 947 948 for (; pindex < end; pindex += 1) { 949 relookup: 950 tobject = object; 951 tpindex = pindex; 952 shadowlookup: 953 /* 954 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 955 * and those pages must be OBJ_ONEMAPPING. 956 */ 957 if (advise == MADV_FREE) { 958 if ((tobject->type != OBJT_DEFAULT && 959 tobject->type != OBJT_SWAP) || 960 (tobject->flags & OBJ_ONEMAPPING) == 0) { 961 continue; 962 } 963 } 964 965 m = vm_page_lookup(tobject, tpindex); 966 967 if (m == NULL) { 968 /* 969 * There may be swap even if there is no backing page 970 */ 971 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 972 swap_pager_freespace(tobject, tpindex, 1); 973 974 /* 975 * next object 976 */ 977 tobject = tobject->backing_object; 978 if (tobject == NULL) 979 continue; 980 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 981 goto shadowlookup; 982 } 983 984 /* 985 * If the page is busy or not in a normal active state, 986 * we skip it. If the page is not managed there are no 987 * page queues to mess with. Things can break if we mess 988 * with pages in any of the below states. 989 */ 990 if ( 991 m->hold_count || 992 m->wire_count || 993 (m->flags & PG_UNMANAGED) || 994 m->valid != VM_PAGE_BITS_ALL 995 ) { 996 continue; 997 } 998 999 if (vm_page_sleep_busy(m, TRUE, "madvpo")) 1000 goto relookup; 1001 1002 if (advise == MADV_WILLNEED) { 1003 vm_page_activate(m); 1004 } else if (advise == MADV_DONTNEED) { 1005 vm_page_dontneed(m); 1006 } else if (advise == MADV_FREE) { 1007 /* 1008 * Mark the page clean. This will allow the page 1009 * to be freed up by the system. However, such pages 1010 * are often reused quickly by malloc()/free() 1011 * so we do not do anything that would cause 1012 * a page fault if we can help it. 1013 * 1014 * Specifically, we do not try to actually free 1015 * the page now nor do we try to put it in the 1016 * cache (which would cause a page fault on reuse). 1017 * 1018 * But we do make the page is freeable as we 1019 * can without actually taking the step of unmapping 1020 * it. 1021 */ 1022 pmap_clear_modify(m); 1023 m->dirty = 0; 1024 m->act_count = 0; 1025 vm_page_dontneed(m); 1026 if (tobject->type == OBJT_SWAP) 1027 swap_pager_freespace(tobject, tpindex, 1); 1028 } 1029 } 1030 } 1031 1032 /* 1033 * vm_object_shadow: 1034 * 1035 * Create a new object which is backed by the 1036 * specified existing object range. The source 1037 * object reference is deallocated. 1038 * 1039 * The new object and offset into that object 1040 * are returned in the source parameters. 1041 */ 1042 1043 void 1044 vm_object_shadow(object, offset, length) 1045 vm_object_t *object; /* IN/OUT */ 1046 vm_ooffset_t *offset; /* IN/OUT */ 1047 vm_size_t length; 1048 { 1049 vm_object_t source; 1050 vm_object_t result; 1051 1052 source = *object; 1053 1054 /* 1055 * Don't create the new object if the old object isn't shared. 1056 */ 1057 1058 if (source != NULL && 1059 source->ref_count == 1 && 1060 source->handle == NULL && 1061 (source->type == OBJT_DEFAULT || 1062 source->type == OBJT_SWAP)) 1063 return; 1064 1065 /* 1066 * Allocate a new object with the given length 1067 */ 1068 1069 if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL) 1070 panic("vm_object_shadow: no object for shadowing"); 1071 1072 /* 1073 * The new object shadows the source object, adding a reference to it. 1074 * Our caller changes his reference to point to the new object, 1075 * removing a reference to the source object. Net result: no change 1076 * of reference count. 1077 * 1078 * Try to optimize the result object's page color when shadowing 1079 * in order to maintain page coloring consistency in the combined 1080 * shadowed object. 1081 */ 1082 result->backing_object = source; 1083 if (source) { 1084 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1085 source->shadow_count++; 1086 source->generation++; 1087 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK; 1088 } 1089 1090 /* 1091 * Store the offset into the source object, and fix up the offset into 1092 * the new object. 1093 */ 1094 1095 result->backing_object_offset = *offset; 1096 1097 /* 1098 * Return the new things 1099 */ 1100 1101 *offset = 0; 1102 *object = result; 1103 } 1104 1105 #define OBSC_TEST_ALL_SHADOWED 0x0001 1106 #define OBSC_COLLAPSE_NOWAIT 0x0002 1107 #define OBSC_COLLAPSE_WAIT 0x0004 1108 1109 static __inline int 1110 vm_object_backing_scan(vm_object_t object, int op) 1111 { 1112 int s; 1113 int r = 1; 1114 vm_page_t p; 1115 vm_object_t backing_object; 1116 vm_pindex_t backing_offset_index; 1117 1118 s = splvm(); 1119 1120 backing_object = object->backing_object; 1121 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1122 1123 /* 1124 * Initial conditions 1125 */ 1126 1127 if (op & OBSC_TEST_ALL_SHADOWED) { 1128 /* 1129 * We do not want to have to test for the existence of 1130 * swap pages in the backing object. XXX but with the 1131 * new swapper this would be pretty easy to do. 1132 * 1133 * XXX what about anonymous MAP_SHARED memory that hasn't 1134 * been ZFOD faulted yet? If we do not test for this, the 1135 * shadow test may succeed! XXX 1136 */ 1137 if (backing_object->type != OBJT_DEFAULT) { 1138 splx(s); 1139 return(0); 1140 } 1141 } 1142 if (op & OBSC_COLLAPSE_WAIT) { 1143 vm_object_set_flag(backing_object, OBJ_DEAD); 1144 } 1145 1146 /* 1147 * Our scan 1148 */ 1149 1150 p = TAILQ_FIRST(&backing_object->memq); 1151 while (p) { 1152 vm_page_t next = TAILQ_NEXT(p, listq); 1153 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1154 1155 if (op & OBSC_TEST_ALL_SHADOWED) { 1156 vm_page_t pp; 1157 1158 /* 1159 * Ignore pages outside the parent object's range 1160 * and outside the parent object's mapping of the 1161 * backing object. 1162 * 1163 * note that we do not busy the backing object's 1164 * page. 1165 */ 1166 1167 if ( 1168 p->pindex < backing_offset_index || 1169 new_pindex >= object->size 1170 ) { 1171 p = next; 1172 continue; 1173 } 1174 1175 /* 1176 * See if the parent has the page or if the parent's 1177 * object pager has the page. If the parent has the 1178 * page but the page is not valid, the parent's 1179 * object pager must have the page. 1180 * 1181 * If this fails, the parent does not completely shadow 1182 * the object and we might as well give up now. 1183 */ 1184 1185 pp = vm_page_lookup(object, new_pindex); 1186 if ( 1187 (pp == NULL || pp->valid == 0) && 1188 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1189 ) { 1190 r = 0; 1191 break; 1192 } 1193 } 1194 1195 /* 1196 * Check for busy page 1197 */ 1198 1199 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1200 vm_page_t pp; 1201 1202 if (op & OBSC_COLLAPSE_NOWAIT) { 1203 if ( 1204 (p->flags & PG_BUSY) || 1205 !p->valid || 1206 p->hold_count || 1207 p->wire_count || 1208 p->busy 1209 ) { 1210 p = next; 1211 continue; 1212 } 1213 } else if (op & OBSC_COLLAPSE_WAIT) { 1214 if (vm_page_sleep_busy(p, TRUE, "vmocol")) { 1215 /* 1216 * If we slept, anything could have 1217 * happened. Since the object is 1218 * marked dead, the backing offset 1219 * should not have changed so we 1220 * just restart our scan. 1221 */ 1222 p = TAILQ_FIRST(&backing_object->memq); 1223 continue; 1224 } 1225 } 1226 1227 /* 1228 * Busy the page 1229 */ 1230 vm_page_busy(p); 1231 1232 KASSERT( 1233 p->object == backing_object, 1234 ("vm_object_qcollapse(): object mismatch") 1235 ); 1236 1237 /* 1238 * Destroy any associated swap 1239 */ 1240 if (backing_object->type == OBJT_SWAP) { 1241 swap_pager_freespace( 1242 backing_object, 1243 p->pindex, 1244 1 1245 ); 1246 } 1247 1248 if ( 1249 p->pindex < backing_offset_index || 1250 new_pindex >= object->size 1251 ) { 1252 /* 1253 * Page is out of the parent object's range, we 1254 * can simply destroy it. 1255 */ 1256 vm_page_protect(p, VM_PROT_NONE); 1257 vm_page_free(p); 1258 p = next; 1259 continue; 1260 } 1261 1262 pp = vm_page_lookup(object, new_pindex); 1263 if ( 1264 pp != NULL || 1265 vm_pager_has_page(object, new_pindex, NULL, NULL) 1266 ) { 1267 /* 1268 * page already exists in parent OR swap exists 1269 * for this location in the parent. Destroy 1270 * the original page from the backing object. 1271 * 1272 * Leave the parent's page alone 1273 */ 1274 vm_page_protect(p, VM_PROT_NONE); 1275 vm_page_free(p); 1276 p = next; 1277 continue; 1278 } 1279 1280 /* 1281 * Page does not exist in parent, rename the 1282 * page from the backing object to the main object. 1283 * 1284 * If the page was mapped to a process, it can remain 1285 * mapped through the rename. 1286 */ 1287 if ((p->queue - p->pc) == PQ_CACHE) 1288 vm_page_deactivate(p); 1289 1290 vm_page_rename(p, object, new_pindex); 1291 /* page automatically made dirty by rename */ 1292 } 1293 p = next; 1294 } 1295 splx(s); 1296 return(r); 1297 } 1298 1299 1300 /* 1301 * this version of collapse allows the operation to occur earlier and 1302 * when paging_in_progress is true for an object... This is not a complete 1303 * operation, but should plug 99.9% of the rest of the leaks. 1304 */ 1305 static void 1306 vm_object_qcollapse(object) 1307 vm_object_t object; 1308 { 1309 vm_object_t backing_object = object->backing_object; 1310 1311 if (backing_object->ref_count != 1) 1312 return; 1313 1314 backing_object->ref_count += 2; 1315 1316 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1317 1318 backing_object->ref_count -= 2; 1319 } 1320 1321 /* 1322 * vm_object_collapse: 1323 * 1324 * Collapse an object with the object backing it. 1325 * Pages in the backing object are moved into the 1326 * parent, and the backing object is deallocated. 1327 */ 1328 void 1329 vm_object_collapse(object) 1330 vm_object_t object; 1331 { 1332 while (TRUE) { 1333 vm_object_t backing_object; 1334 1335 /* 1336 * Verify that the conditions are right for collapse: 1337 * 1338 * The object exists and the backing object exists. 1339 */ 1340 if (object == NULL) 1341 break; 1342 1343 if ((backing_object = object->backing_object) == NULL) 1344 break; 1345 1346 /* 1347 * we check the backing object first, because it is most likely 1348 * not collapsable. 1349 */ 1350 if (backing_object->handle != NULL || 1351 (backing_object->type != OBJT_DEFAULT && 1352 backing_object->type != OBJT_SWAP) || 1353 (backing_object->flags & OBJ_DEAD) || 1354 object->handle != NULL || 1355 (object->type != OBJT_DEFAULT && 1356 object->type != OBJT_SWAP) || 1357 (object->flags & OBJ_DEAD)) { 1358 break; 1359 } 1360 1361 if ( 1362 object->paging_in_progress != 0 || 1363 backing_object->paging_in_progress != 0 1364 ) { 1365 vm_object_qcollapse(object); 1366 break; 1367 } 1368 1369 /* 1370 * We know that we can either collapse the backing object (if 1371 * the parent is the only reference to it) or (perhaps) have 1372 * the parent bypass the object if the parent happens to shadow 1373 * all the resident pages in the entire backing object. 1374 * 1375 * This is ignoring pager-backed pages such as swap pages. 1376 * vm_object_backing_scan fails the shadowing test in this 1377 * case. 1378 */ 1379 1380 if (backing_object->ref_count == 1) { 1381 /* 1382 * If there is exactly one reference to the backing 1383 * object, we can collapse it into the parent. 1384 */ 1385 1386 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1387 1388 /* 1389 * Move the pager from backing_object to object. 1390 */ 1391 1392 if (backing_object->type == OBJT_SWAP) { 1393 vm_object_pip_add(backing_object, 1); 1394 1395 /* 1396 * scrap the paging_offset junk and do a 1397 * discrete copy. This also removes major 1398 * assumptions about how the swap-pager 1399 * works from where it doesn't belong. The 1400 * new swapper is able to optimize the 1401 * destroy-source case. 1402 */ 1403 1404 vm_object_pip_add(object, 1); 1405 swap_pager_copy( 1406 backing_object, 1407 object, 1408 OFF_TO_IDX(object->backing_object_offset), TRUE); 1409 vm_object_pip_wakeup(object); 1410 1411 vm_object_pip_wakeup(backing_object); 1412 } 1413 /* 1414 * Object now shadows whatever backing_object did. 1415 * Note that the reference to 1416 * backing_object->backing_object moves from within 1417 * backing_object to within object. 1418 */ 1419 1420 LIST_REMOVE(object, shadow_list); 1421 object->backing_object->shadow_count--; 1422 object->backing_object->generation++; 1423 if (backing_object->backing_object) { 1424 LIST_REMOVE(backing_object, shadow_list); 1425 backing_object->backing_object->shadow_count--; 1426 backing_object->backing_object->generation++; 1427 } 1428 object->backing_object = backing_object->backing_object; 1429 if (object->backing_object) { 1430 LIST_INSERT_HEAD( 1431 &object->backing_object->shadow_head, 1432 object, 1433 shadow_list 1434 ); 1435 object->backing_object->shadow_count++; 1436 object->backing_object->generation++; 1437 } 1438 1439 object->backing_object_offset += 1440 backing_object->backing_object_offset; 1441 1442 /* 1443 * Discard backing_object. 1444 * 1445 * Since the backing object has no pages, no pager left, 1446 * and no object references within it, all that is 1447 * necessary is to dispose of it. 1448 */ 1449 1450 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1451 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object)); 1452 TAILQ_REMOVE( 1453 &vm_object_list, 1454 backing_object, 1455 object_list 1456 ); 1457 vm_object_count--; 1458 1459 zfree(obj_zone, backing_object); 1460 1461 object_collapses++; 1462 } else { 1463 vm_object_t new_backing_object; 1464 1465 /* 1466 * If we do not entirely shadow the backing object, 1467 * there is nothing we can do so we give up. 1468 */ 1469 1470 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1471 break; 1472 } 1473 1474 /* 1475 * Make the parent shadow the next object in the 1476 * chain. Deallocating backing_object will not remove 1477 * it, since its reference count is at least 2. 1478 */ 1479 1480 LIST_REMOVE(object, shadow_list); 1481 backing_object->shadow_count--; 1482 backing_object->generation++; 1483 1484 new_backing_object = backing_object->backing_object; 1485 if ((object->backing_object = new_backing_object) != NULL) { 1486 vm_object_reference(new_backing_object); 1487 LIST_INSERT_HEAD( 1488 &new_backing_object->shadow_head, 1489 object, 1490 shadow_list 1491 ); 1492 new_backing_object->shadow_count++; 1493 new_backing_object->generation++; 1494 object->backing_object_offset += 1495 backing_object->backing_object_offset; 1496 } 1497 1498 /* 1499 * Drop the reference count on backing_object. Since 1500 * its ref_count was at least 2, it will not vanish; 1501 * so we don't need to call vm_object_deallocate, but 1502 * we do anyway. 1503 */ 1504 vm_object_deallocate(backing_object); 1505 object_bypasses++; 1506 } 1507 1508 /* 1509 * Try again with this object's new backing object. 1510 */ 1511 } 1512 } 1513 1514 /* 1515 * vm_object_page_remove: [internal] 1516 * 1517 * Removes all physical pages in the specified 1518 * object range from the object's list of pages. 1519 * 1520 * The object must be locked. 1521 */ 1522 void 1523 vm_object_page_remove(object, start, end, clean_only) 1524 vm_object_t object; 1525 vm_pindex_t start; 1526 vm_pindex_t end; 1527 boolean_t clean_only; 1528 { 1529 vm_page_t p, next; 1530 unsigned int size; 1531 int all; 1532 1533 if (object == NULL || 1534 object->resident_page_count == 0) 1535 return; 1536 1537 all = ((end == 0) && (start == 0)); 1538 1539 /* 1540 * Since physically-backed objects do not use managed pages, we can't 1541 * remove pages from the object (we must instead remove the page 1542 * references, and then destroy the object). 1543 */ 1544 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object")); 1545 1546 vm_object_pip_add(object, 1); 1547 again: 1548 size = end - start; 1549 if (all || size > object->resident_page_count / 4) { 1550 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 1551 next = TAILQ_NEXT(p, listq); 1552 if (all || ((start <= p->pindex) && (p->pindex < end))) { 1553 if (p->wire_count != 0) { 1554 vm_page_protect(p, VM_PROT_NONE); 1555 if (!clean_only) 1556 p->valid = 0; 1557 continue; 1558 } 1559 1560 /* 1561 * The busy flags are only cleared at 1562 * interrupt -- minimize the spl transitions 1563 */ 1564 1565 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1566 goto again; 1567 1568 if (clean_only && p->valid) { 1569 vm_page_test_dirty(p); 1570 if (p->valid & p->dirty) 1571 continue; 1572 } 1573 1574 vm_page_busy(p); 1575 vm_page_protect(p, VM_PROT_NONE); 1576 vm_page_free(p); 1577 } 1578 } 1579 } else { 1580 while (size > 0) { 1581 if ((p = vm_page_lookup(object, start)) != 0) { 1582 1583 if (p->wire_count != 0) { 1584 vm_page_protect(p, VM_PROT_NONE); 1585 if (!clean_only) 1586 p->valid = 0; 1587 start += 1; 1588 size -= 1; 1589 continue; 1590 } 1591 1592 /* 1593 * The busy flags are only cleared at 1594 * interrupt -- minimize the spl transitions 1595 */ 1596 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1597 goto again; 1598 1599 if (clean_only && p->valid) { 1600 vm_page_test_dirty(p); 1601 if (p->valid & p->dirty) { 1602 start += 1; 1603 size -= 1; 1604 continue; 1605 } 1606 } 1607 1608 vm_page_busy(p); 1609 vm_page_protect(p, VM_PROT_NONE); 1610 vm_page_free(p); 1611 } 1612 start += 1; 1613 size -= 1; 1614 } 1615 } 1616 vm_object_pip_wakeup(object); 1617 } 1618 1619 /* 1620 * Routine: vm_object_coalesce 1621 * Function: Coalesces two objects backing up adjoining 1622 * regions of memory into a single object. 1623 * 1624 * returns TRUE if objects were combined. 1625 * 1626 * NOTE: Only works at the moment if the second object is NULL - 1627 * if it's not, which object do we lock first? 1628 * 1629 * Parameters: 1630 * prev_object First object to coalesce 1631 * prev_offset Offset into prev_object 1632 * next_object Second object into coalesce 1633 * next_offset Offset into next_object 1634 * 1635 * prev_size Size of reference to prev_object 1636 * next_size Size of reference to next_object 1637 * 1638 * Conditions: 1639 * The object must *not* be locked. 1640 */ 1641 boolean_t 1642 vm_object_coalesce(prev_object, prev_pindex, prev_size, next_size) 1643 vm_object_t prev_object; 1644 vm_pindex_t prev_pindex; 1645 vm_size_t prev_size, next_size; 1646 { 1647 vm_pindex_t next_pindex; 1648 1649 if (prev_object == NULL) { 1650 return (TRUE); 1651 } 1652 1653 if (prev_object->type != OBJT_DEFAULT && 1654 prev_object->type != OBJT_SWAP) { 1655 return (FALSE); 1656 } 1657 1658 /* 1659 * Try to collapse the object first 1660 */ 1661 vm_object_collapse(prev_object); 1662 1663 /* 1664 * Can't coalesce if: . more than one reference . paged out . shadows 1665 * another object . has a copy elsewhere (any of which mean that the 1666 * pages not mapped to prev_entry may be in use anyway) 1667 */ 1668 1669 if (prev_object->backing_object != NULL) { 1670 return (FALSE); 1671 } 1672 1673 prev_size >>= PAGE_SHIFT; 1674 next_size >>= PAGE_SHIFT; 1675 next_pindex = prev_pindex + prev_size; 1676 1677 if ((prev_object->ref_count > 1) && 1678 (prev_object->size != next_pindex)) { 1679 return (FALSE); 1680 } 1681 1682 /* 1683 * Remove any pages that may still be in the object from a previous 1684 * deallocation. 1685 */ 1686 if (next_pindex < prev_object->size) { 1687 vm_object_page_remove(prev_object, 1688 next_pindex, 1689 next_pindex + next_size, FALSE); 1690 if (prev_object->type == OBJT_SWAP) 1691 swap_pager_freespace(prev_object, 1692 next_pindex, next_size); 1693 } 1694 1695 /* 1696 * Extend the object if necessary. 1697 */ 1698 if (next_pindex + next_size > prev_object->size) 1699 prev_object->size = next_pindex + next_size; 1700 1701 return (TRUE); 1702 } 1703 1704 void 1705 vm_object_set_writeable_dirty(vm_object_t object) 1706 { 1707 struct vnode *vp; 1708 1709 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1710 if (object->type == OBJT_VNODE && 1711 (vp = (struct vnode *)object->handle) != NULL) { 1712 if ((vp->v_flag & VOBJDIRTY) == 0) { 1713 simple_lock(&vp->v_interlock); 1714 vp->v_flag |= VOBJDIRTY; 1715 simple_unlock(&vp->v_interlock); 1716 } 1717 } 1718 } 1719 1720 1721 1722 #include "opt_ddb.h" 1723 #ifdef DDB 1724 #include <sys/kernel.h> 1725 1726 #include <sys/cons.h> 1727 1728 #include <ddb/ddb.h> 1729 1730 static int _vm_object_in_map __P((vm_map_t map, vm_object_t object, 1731 vm_map_entry_t entry)); 1732 static int vm_object_in_map __P((vm_object_t object)); 1733 1734 static int 1735 _vm_object_in_map(map, object, entry) 1736 vm_map_t map; 1737 vm_object_t object; 1738 vm_map_entry_t entry; 1739 { 1740 vm_map_t tmpm; 1741 vm_map_entry_t tmpe; 1742 vm_object_t obj; 1743 int entcount; 1744 1745 if (map == 0) 1746 return 0; 1747 1748 if (entry == 0) { 1749 tmpe = map->header.next; 1750 entcount = map->nentries; 1751 while (entcount-- && (tmpe != &map->header)) { 1752 if( _vm_object_in_map(map, object, tmpe)) { 1753 return 1; 1754 } 1755 tmpe = tmpe->next; 1756 } 1757 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1758 tmpm = entry->object.sub_map; 1759 tmpe = tmpm->header.next; 1760 entcount = tmpm->nentries; 1761 while (entcount-- && tmpe != &tmpm->header) { 1762 if( _vm_object_in_map(tmpm, object, tmpe)) { 1763 return 1; 1764 } 1765 tmpe = tmpe->next; 1766 } 1767 } else if ((obj = entry->object.vm_object) != NULL) { 1768 for(; obj; obj=obj->backing_object) 1769 if( obj == object) { 1770 return 1; 1771 } 1772 } 1773 return 0; 1774 } 1775 1776 static int 1777 vm_object_in_map( object) 1778 vm_object_t object; 1779 { 1780 struct proc *p; 1781 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 1782 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1783 continue; 1784 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) 1785 return 1; 1786 } 1787 if( _vm_object_in_map( kernel_map, object, 0)) 1788 return 1; 1789 if( _vm_object_in_map( kmem_map, object, 0)) 1790 return 1; 1791 if( _vm_object_in_map( pager_map, object, 0)) 1792 return 1; 1793 if( _vm_object_in_map( buffer_map, object, 0)) 1794 return 1; 1795 if( _vm_object_in_map( mb_map, object, 0)) 1796 return 1; 1797 return 0; 1798 } 1799 1800 DB_SHOW_COMMAND(vmochk, vm_object_check) 1801 { 1802 vm_object_t object; 1803 1804 /* 1805 * make sure that internal objs are in a map somewhere 1806 * and none have zero ref counts. 1807 */ 1808 for (object = TAILQ_FIRST(&vm_object_list); 1809 object != NULL; 1810 object = TAILQ_NEXT(object, object_list)) { 1811 if (object->handle == NULL && 1812 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1813 if (object->ref_count == 0) { 1814 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1815 (long)object->size); 1816 } 1817 if (!vm_object_in_map(object)) { 1818 db_printf( 1819 "vmochk: internal obj is not in a map: " 1820 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1821 object->ref_count, (u_long)object->size, 1822 (u_long)object->size, 1823 (void *)object->backing_object); 1824 } 1825 } 1826 } 1827 } 1828 1829 /* 1830 * vm_object_print: [ debug ] 1831 */ 1832 DB_SHOW_COMMAND(object, vm_object_print_static) 1833 { 1834 /* XXX convert args. */ 1835 vm_object_t object = (vm_object_t)addr; 1836 boolean_t full = have_addr; 1837 1838 vm_page_t p; 1839 1840 /* XXX count is an (unused) arg. Avoid shadowing it. */ 1841 #define count was_count 1842 1843 int count; 1844 1845 if (object == NULL) 1846 return; 1847 1848 db_iprintf( 1849 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n", 1850 object, (int)object->type, (u_long)object->size, 1851 object->resident_page_count, object->ref_count, object->flags); 1852 /* 1853 * XXX no %qd in kernel. Truncate object->backing_object_offset. 1854 */ 1855 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n", 1856 object->shadow_count, 1857 object->backing_object ? object->backing_object->ref_count : 0, 1858 object->backing_object, (long)object->backing_object_offset); 1859 1860 if (!full) 1861 return; 1862 1863 db_indent += 2; 1864 count = 0; 1865 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = TAILQ_NEXT(p, listq)) { 1866 if (count == 0) 1867 db_iprintf("memory:="); 1868 else if (count == 6) { 1869 db_printf("\n"); 1870 db_iprintf(" ..."); 1871 count = 0; 1872 } else 1873 db_printf(","); 1874 count++; 1875 1876 db_printf("(off=0x%lx,page=0x%lx)", 1877 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p)); 1878 } 1879 if (count != 0) 1880 db_printf("\n"); 1881 db_indent -= 2; 1882 } 1883 1884 /* XXX. */ 1885 #undef count 1886 1887 /* XXX need this non-static entry for calling from vm_map_print. */ 1888 void 1889 vm_object_print(addr, have_addr, count, modif) 1890 /* db_expr_t */ long addr; 1891 boolean_t have_addr; 1892 /* db_expr_t */ long count; 1893 char *modif; 1894 { 1895 vm_object_print_static(addr, have_addr, count, modif); 1896 } 1897 1898 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 1899 { 1900 vm_object_t object; 1901 int nl = 0; 1902 int c; 1903 for (object = TAILQ_FIRST(&vm_object_list); 1904 object != NULL; 1905 object = TAILQ_NEXT(object, object_list)) { 1906 vm_pindex_t idx, fidx; 1907 vm_pindex_t osize; 1908 vm_offset_t pa = -1, padiff; 1909 int rcount; 1910 vm_page_t m; 1911 1912 db_printf("new object: %p\n", (void *)object); 1913 if ( nl > 18) { 1914 c = cngetc(); 1915 if (c != ' ') 1916 return; 1917 nl = 0; 1918 } 1919 nl++; 1920 rcount = 0; 1921 fidx = 0; 1922 osize = object->size; 1923 if (osize > 128) 1924 osize = 128; 1925 for(idx=0;idx<osize;idx++) { 1926 m = vm_page_lookup(object, idx); 1927 if (m == NULL) { 1928 if (rcount) { 1929 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1930 (long)fidx, rcount, (long)pa); 1931 if ( nl > 18) { 1932 c = cngetc(); 1933 if (c != ' ') 1934 return; 1935 nl = 0; 1936 } 1937 nl++; 1938 rcount = 0; 1939 } 1940 continue; 1941 } 1942 1943 1944 if (rcount && 1945 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 1946 ++rcount; 1947 continue; 1948 } 1949 if (rcount) { 1950 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 1951 padiff >>= PAGE_SHIFT; 1952 padiff &= PQ_L2_MASK; 1953 if (padiff == 0) { 1954 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 1955 ++rcount; 1956 continue; 1957 } 1958 db_printf(" index(%ld)run(%d)pa(0x%lx)", 1959 (long)fidx, rcount, (long)pa); 1960 db_printf("pd(%ld)\n", (long)padiff); 1961 if ( nl > 18) { 1962 c = cngetc(); 1963 if (c != ' ') 1964 return; 1965 nl = 0; 1966 } 1967 nl++; 1968 } 1969 fidx = idx; 1970 pa = VM_PAGE_TO_PHYS(m); 1971 rcount = 1; 1972 } 1973 if (rcount) { 1974 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1975 (long)fidx, rcount, (long)pa); 1976 if ( nl > 18) { 1977 c = cngetc(); 1978 if (c != ' ') 1979 return; 1980 nl = 0; 1981 } 1982 nl++; 1983 } 1984 } 1985 } 1986 #endif /* DDB */ 1987