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 * $DragonFly: src/sys/vm/vm_object.c,v 1.13 2004/03/01 06:33:24 dillon Exp $ 66 */ 67 68 /* 69 * Virtual memory object module. 70 */ 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/proc.h> /* for curproc, pageproc */ 75 #include <sys/vnode.h> 76 #include <sys/vmmeter.h> 77 #include <sys/mman.h> 78 #include <sys/mount.h> 79 #include <sys/kernel.h> 80 #include <sys/sysctl.h> 81 82 #include <vm/vm.h> 83 #include <vm/vm_param.h> 84 #include <vm/pmap.h> 85 #include <vm/vm_map.h> 86 #include <vm/vm_object.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_pageout.h> 89 #include <vm/vm_pager.h> 90 #include <vm/swap_pager.h> 91 #include <vm/vm_kern.h> 92 #include <vm/vm_extern.h> 93 #include <vm/vm_zone.h> 94 95 #define EASY_SCAN_FACTOR 8 96 97 #define MSYNC_FLUSH_HARDSEQ 0x01 98 #define MSYNC_FLUSH_SOFTSEQ 0x02 99 100 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 101 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, 102 CTLFLAG_RW, &msync_flush_flags, 0, ""); 103 104 static void vm_object_qcollapse (vm_object_t object); 105 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 106 107 /* 108 * Virtual memory objects maintain the actual data 109 * associated with allocated virtual memory. A given 110 * page of memory exists within exactly one object. 111 * 112 * An object is only deallocated when all "references" 113 * are given up. Only one "reference" to a given 114 * region of an object should be writeable. 115 * 116 * Associated with each object is a list of all resident 117 * memory pages belonging to that object; this list is 118 * maintained by the "vm_page" module, and locked by the object's 119 * lock. 120 * 121 * Each object also records a "pager" routine which is 122 * used to retrieve (and store) pages to the proper backing 123 * storage. In addition, objects may be backed by other 124 * objects from which they were virtual-copied. 125 * 126 * The only items within the object structure which are 127 * modified after time of creation are: 128 * reference count locked by object's lock 129 * pager routine locked by object's lock 130 * 131 */ 132 133 struct object_q vm_object_list; 134 static struct lwkt_token vm_object_list_token; 135 static long vm_object_count; /* count of all objects */ 136 vm_object_t kernel_object; 137 vm_object_t kmem_object; 138 static struct vm_object kernel_object_store; 139 static struct vm_object kmem_object_store; 140 extern int vm_pageout_page_count; 141 142 static long object_collapses; 143 static long object_bypasses; 144 static int next_index; 145 static vm_zone_t obj_zone; 146 static struct vm_zone obj_zone_store; 147 static int object_hash_rand; 148 #define VM_OBJECTS_INIT 256 149 static struct vm_object vm_objects_init[VM_OBJECTS_INIT]; 150 151 void 152 _vm_object_allocate(type, size, object) 153 objtype_t type; 154 vm_size_t size; 155 vm_object_t object; 156 { 157 int incr; 158 TAILQ_INIT(&object->memq); 159 LIST_INIT(&object->shadow_head); 160 161 object->type = type; 162 object->size = size; 163 object->ref_count = 1; 164 object->flags = 0; 165 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 166 vm_object_set_flag(object, OBJ_ONEMAPPING); 167 object->paging_in_progress = 0; 168 object->resident_page_count = 0; 169 object->shadow_count = 0; 170 object->pg_color = next_index; 171 if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 172 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 173 else 174 incr = size; 175 next_index = (next_index + incr) & PQ_L2_MASK; 176 object->handle = NULL; 177 object->backing_object = NULL; 178 object->backing_object_offset = (vm_ooffset_t) 0; 179 /* 180 * Try to generate a number that will spread objects out in the 181 * hash table. We 'wipe' new objects across the hash in 128 page 182 * increments plus 1 more to offset it a little more by the time 183 * it wraps around. 184 */ 185 object->hash_rand = object_hash_rand - 129; 186 187 object->generation++; 188 189 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 190 vm_object_count++; 191 object_hash_rand = object->hash_rand; 192 } 193 194 /* 195 * vm_object_init: 196 * 197 * Initialize the VM objects module. 198 */ 199 void 200 vm_object_init() 201 { 202 TAILQ_INIT(&vm_object_list); 203 lwkt_token_init(&vm_object_list_token); 204 vm_object_count = 0; 205 206 kernel_object = &kernel_object_store; 207 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 208 kernel_object); 209 210 kmem_object = &kmem_object_store; 211 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 212 kmem_object); 213 214 obj_zone = &obj_zone_store; 215 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object), 216 vm_objects_init, VM_OBJECTS_INIT); 217 } 218 219 void 220 vm_object_init2() 221 { 222 zinitna(obj_zone, NULL, NULL, 0, 0, ZONE_PANICFAIL, 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, NULL, 267 LK_RETRY|LK_NOOBJ, curthread)) { 268 printf("vm_object_reference: delay in getting object\n"); 269 } 270 } 271 } 272 273 void 274 vm_object_vndeallocate(object) 275 vm_object_t object; 276 { 277 struct vnode *vp = (struct vnode *) object->handle; 278 279 KASSERT(object->type == OBJT_VNODE, 280 ("vm_object_vndeallocate: not a vnode object")); 281 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 282 #ifdef INVARIANTS 283 if (object->ref_count == 0) { 284 vprint("vm_object_vndeallocate", vp); 285 panic("vm_object_vndeallocate: bad object reference count"); 286 } 287 #endif 288 289 object->ref_count--; 290 if (object->ref_count == 0) { 291 vp->v_flag &= ~VTEXT; 292 vm_object_clear_flag(object, OBJ_OPT); 293 } 294 vrele(vp); 295 } 296 297 /* 298 * vm_object_deallocate: 299 * 300 * Release a reference to the specified object, 301 * gained either through a vm_object_allocate 302 * or a vm_object_reference call. When all references 303 * are gone, storage associated with this object 304 * may be relinquished. 305 * 306 * No object may be locked. 307 */ 308 void 309 vm_object_deallocate(object) 310 vm_object_t object; 311 { 312 vm_object_t temp; 313 314 while (object != NULL) { 315 316 if (object->type == OBJT_VNODE) { 317 vm_object_vndeallocate(object); 318 return; 319 } 320 321 if (object->ref_count == 0) { 322 panic("vm_object_deallocate: object deallocated too many times: %d", object->type); 323 } else if (object->ref_count > 2) { 324 object->ref_count--; 325 return; 326 } 327 328 /* 329 * Here on ref_count of one or two, which are special cases for 330 * objects. 331 */ 332 if ((object->ref_count == 2) && (object->shadow_count == 0)) { 333 vm_object_set_flag(object, OBJ_ONEMAPPING); 334 object->ref_count--; 335 return; 336 } else if ((object->ref_count == 2) && (object->shadow_count == 1)) { 337 object->ref_count--; 338 if ((object->handle == NULL) && 339 (object->type == OBJT_DEFAULT || 340 object->type == OBJT_SWAP)) { 341 vm_object_t robject; 342 343 robject = LIST_FIRST(&object->shadow_head); 344 KASSERT(robject != NULL, 345 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 346 object->ref_count, 347 object->shadow_count)); 348 if ((robject->handle == NULL) && 349 (robject->type == OBJT_DEFAULT || 350 robject->type == OBJT_SWAP)) { 351 352 robject->ref_count++; 353 354 while ( 355 robject->paging_in_progress || 356 object->paging_in_progress 357 ) { 358 vm_object_pip_sleep(robject, "objde1"); 359 vm_object_pip_sleep(object, "objde2"); 360 } 361 362 if (robject->ref_count == 1) { 363 robject->ref_count--; 364 object = robject; 365 goto doterm; 366 } 367 368 object = robject; 369 vm_object_collapse(object); 370 continue; 371 } 372 } 373 374 return; 375 376 } else { 377 object->ref_count--; 378 if (object->ref_count != 0) 379 return; 380 } 381 382 doterm: 383 384 temp = object->backing_object; 385 if (temp) { 386 LIST_REMOVE(object, shadow_list); 387 temp->shadow_count--; 388 if (temp->ref_count == 0) 389 vm_object_clear_flag(temp, OBJ_OPT); 390 temp->generation++; 391 object->backing_object = NULL; 392 } 393 394 /* 395 * Don't double-terminate, we could be in a termination 396 * recursion due to the terminate having to sync data 397 * to disk. 398 */ 399 if ((object->flags & OBJ_DEAD) == 0) 400 vm_object_terminate(object); 401 object = temp; 402 } 403 } 404 405 /* 406 * vm_object_terminate actually destroys the specified object, freeing 407 * up all previously used resources. 408 * 409 * The object must be locked. 410 * This routine may block. 411 */ 412 void 413 vm_object_terminate(object) 414 vm_object_t object; 415 { 416 lwkt_tokref ilock; 417 vm_page_t p; 418 int s; 419 420 /* 421 * Make sure no one uses us. 422 */ 423 vm_object_set_flag(object, OBJ_DEAD); 424 425 /* 426 * wait for the pageout daemon to be done with the object 427 */ 428 vm_object_pip_wait(object, "objtrm"); 429 430 KASSERT(!object->paging_in_progress, 431 ("vm_object_terminate: pageout in progress")); 432 433 /* 434 * Clean and free the pages, as appropriate. All references to the 435 * object are gone, so we don't need to lock it. 436 */ 437 if (object->type == OBJT_VNODE) { 438 struct vnode *vp; 439 440 /* 441 * Freeze optimized copies. 442 */ 443 vm_freeze_copyopts(object, 0, object->size); 444 445 /* 446 * Clean pages and flush buffers. 447 */ 448 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 449 450 vp = (struct vnode *) object->handle; 451 vinvalbuf(vp, V_SAVE, NULL, 0, 0); 452 } 453 454 /* 455 * Wait for any I/O to complete, after which there had better not 456 * be any references left on the object. 457 */ 458 vm_object_pip_wait(object, "objtrm"); 459 460 if (object->ref_count != 0) 461 panic("vm_object_terminate: object with references, ref_count=%d", object->ref_count); 462 463 /* 464 * Now free any remaining pages. For internal objects, this also 465 * removes them from paging queues. Don't free wired pages, just 466 * remove them from the object. 467 */ 468 s = splvm(); 469 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 470 if (p->busy || (p->flags & PG_BUSY)) 471 panic("vm_object_terminate: freeing busy page %p\n", p); 472 if (p->wire_count == 0) { 473 vm_page_busy(p); 474 vm_page_free(p); 475 mycpu->gd_cnt.v_pfree++; 476 } else { 477 vm_page_busy(p); 478 vm_page_remove(p); 479 } 480 } 481 splx(s); 482 483 /* 484 * Let the pager know object is dead. 485 */ 486 vm_pager_deallocate(object); 487 488 /* 489 * Remove the object from the global object list. 490 */ 491 lwkt_gettoken(&ilock, &vm_object_list_token); 492 TAILQ_REMOVE(&vm_object_list, object, object_list); 493 lwkt_reltoken(&ilock); 494 495 wakeup(object); 496 497 /* 498 * Free the space for the object. 499 */ 500 zfree(obj_zone, object); 501 } 502 503 /* 504 * vm_object_page_clean 505 * 506 * Clean all dirty pages in the specified range of object. Leaves page 507 * on whatever queue it is currently on. If NOSYNC is set then do not 508 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 509 * leaving the object dirty. 510 * 511 * When stuffing pages asynchronously, allow clustering. XXX we need a 512 * synchronous clustering mode implementation. 513 * 514 * Odd semantics: if start == end, we clean everything. 515 * 516 * The object must be locked. 517 */ 518 519 void 520 vm_object_page_clean(object, start, end, flags) 521 vm_object_t object; 522 vm_pindex_t start; 523 vm_pindex_t end; 524 int flags; 525 { 526 vm_page_t p, np; 527 vm_offset_t tstart, tend; 528 vm_pindex_t pi; 529 struct vnode *vp; 530 int clearobjflags; 531 int pagerflags; 532 int curgeneration; 533 lwkt_tokref vlock; 534 535 if (object->type != OBJT_VNODE || 536 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 537 return; 538 539 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 540 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 541 542 vp = object->handle; 543 544 vm_object_set_flag(object, OBJ_CLEANING); 545 546 /* 547 * Handle 'entire object' case 548 */ 549 tstart = start; 550 if (end == 0) { 551 tend = object->size; 552 } else { 553 tend = end; 554 } 555 556 /* 557 * If the caller is smart and only msync()s a range he knows is 558 * dirty, we may be able to avoid an object scan. This results in 559 * a phenominal improvement in performance. We cannot do this 560 * as a matter of course because the object may be huge - e.g. 561 * the size might be in the gigabytes or terrabytes. 562 */ 563 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 564 vm_offset_t tscan; 565 int scanlimit; 566 int scanreset; 567 568 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 569 if (scanreset < 16) 570 scanreset = 16; 571 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 572 573 scanlimit = scanreset; 574 tscan = tstart; 575 while (tscan < tend) { 576 curgeneration = object->generation; 577 p = vm_page_lookup(object, tscan); 578 if (p == NULL || p->valid == 0 || 579 (p->queue - p->pc) == PQ_CACHE) { 580 if (--scanlimit == 0) 581 break; 582 ++tscan; 583 continue; 584 } 585 vm_page_test_dirty(p); 586 if ((p->dirty & p->valid) == 0) { 587 if (--scanlimit == 0) 588 break; 589 ++tscan; 590 continue; 591 } 592 /* 593 * If we have been asked to skip nosync pages and 594 * this is a nosync page, we can't continue. 595 */ 596 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 597 if (--scanlimit == 0) 598 break; 599 ++tscan; 600 continue; 601 } 602 scanlimit = scanreset; 603 604 /* 605 * This returns 0 if it was unable to busy the first 606 * page (i.e. had to sleep). 607 */ 608 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 609 } 610 611 /* 612 * If everything was dirty and we flushed it successfully, 613 * and the requested range is not the entire object, we 614 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 615 * return immediately. 616 */ 617 if (tscan >= tend && (tstart || tend < object->size)) { 618 vm_object_clear_flag(object, OBJ_CLEANING); 619 return; 620 } 621 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 622 } 623 624 /* 625 * Generally set CLEANCHK interlock and make the page read-only so 626 * we can then clear the object flags. 627 * 628 * However, if this is a nosync mmap then the object is likely to 629 * stay dirty so do not mess with the page and do not clear the 630 * object flags. 631 */ 632 633 clearobjflags = 1; 634 635 for(p = TAILQ_FIRST(&object->memq); p; p = TAILQ_NEXT(p, listq)) { 636 vm_page_flag_set(p, PG_CLEANCHK); 637 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 638 clearobjflags = 0; 639 else 640 vm_page_protect(p, VM_PROT_READ); 641 } 642 643 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 644 struct vnode *vp; 645 646 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 647 if (object->type == OBJT_VNODE && 648 (vp = (struct vnode *)object->handle) != NULL) { 649 if (vp->v_flag & VOBJDIRTY) { 650 lwkt_gettoken(&vlock, vp->v_interlock); 651 vp->v_flag &= ~VOBJDIRTY; 652 lwkt_reltoken(&vlock); 653 } 654 } 655 } 656 657 rescan: 658 curgeneration = object->generation; 659 660 for(p = TAILQ_FIRST(&object->memq); p; p = np) { 661 int n; 662 663 np = TAILQ_NEXT(p, listq); 664 665 again: 666 pi = p->pindex; 667 if (((p->flags & PG_CLEANCHK) == 0) || 668 (pi < tstart) || (pi >= tend) || 669 (p->valid == 0) || 670 ((p->queue - p->pc) == PQ_CACHE)) { 671 vm_page_flag_clear(p, PG_CLEANCHK); 672 continue; 673 } 674 675 vm_page_test_dirty(p); 676 if ((p->dirty & p->valid) == 0) { 677 vm_page_flag_clear(p, PG_CLEANCHK); 678 continue; 679 } 680 681 /* 682 * If we have been asked to skip nosync pages and this is a 683 * nosync page, skip it. Note that the object flags were 684 * not cleared in this case so we do not have to set them. 685 */ 686 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 687 vm_page_flag_clear(p, PG_CLEANCHK); 688 continue; 689 } 690 691 n = vm_object_page_collect_flush(object, p, 692 curgeneration, pagerflags); 693 if (n == 0) 694 goto rescan; 695 if (object->generation != curgeneration) 696 goto rescan; 697 698 /* 699 * Try to optimize the next page. If we can't we pick up 700 * our (random) scan where we left off. 701 */ 702 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 703 if ((p = vm_page_lookup(object, pi + n)) != NULL) 704 goto again; 705 } 706 } 707 708 #if 0 709 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 710 #endif 711 712 vm_object_clear_flag(object, OBJ_CLEANING); 713 return; 714 } 715 716 static int 717 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 718 { 719 int runlen; 720 int s; 721 int maxf; 722 int chkb; 723 int maxb; 724 int i; 725 vm_pindex_t pi; 726 vm_page_t maf[vm_pageout_page_count]; 727 vm_page_t mab[vm_pageout_page_count]; 728 vm_page_t ma[vm_pageout_page_count]; 729 730 s = splvm(); 731 pi = p->pindex; 732 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) { 733 if (object->generation != curgeneration) { 734 splx(s); 735 return(0); 736 } 737 } 738 739 maxf = 0; 740 for(i = 1; i < vm_pageout_page_count; i++) { 741 vm_page_t tp; 742 743 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 744 if ((tp->flags & PG_BUSY) || 745 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 746 (tp->flags & PG_CLEANCHK) == 0) || 747 (tp->busy != 0)) 748 break; 749 if((tp->queue - tp->pc) == PQ_CACHE) { 750 vm_page_flag_clear(tp, PG_CLEANCHK); 751 break; 752 } 753 vm_page_test_dirty(tp); 754 if ((tp->dirty & tp->valid) == 0) { 755 vm_page_flag_clear(tp, PG_CLEANCHK); 756 break; 757 } 758 maf[ i - 1 ] = tp; 759 maxf++; 760 continue; 761 } 762 break; 763 } 764 765 maxb = 0; 766 chkb = vm_pageout_page_count - maxf; 767 if (chkb) { 768 for(i = 1; i < chkb;i++) { 769 vm_page_t tp; 770 771 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 772 if ((tp->flags & PG_BUSY) || 773 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 774 (tp->flags & PG_CLEANCHK) == 0) || 775 (tp->busy != 0)) 776 break; 777 if((tp->queue - tp->pc) == PQ_CACHE) { 778 vm_page_flag_clear(tp, PG_CLEANCHK); 779 break; 780 } 781 vm_page_test_dirty(tp); 782 if ((tp->dirty & tp->valid) == 0) { 783 vm_page_flag_clear(tp, PG_CLEANCHK); 784 break; 785 } 786 mab[ i - 1 ] = tp; 787 maxb++; 788 continue; 789 } 790 break; 791 } 792 } 793 794 for(i = 0; i < maxb; i++) { 795 int index = (maxb - i) - 1; 796 ma[index] = mab[i]; 797 vm_page_flag_clear(ma[index], PG_CLEANCHK); 798 } 799 vm_page_flag_clear(p, PG_CLEANCHK); 800 ma[maxb] = p; 801 for(i = 0; i < maxf; i++) { 802 int index = (maxb + i) + 1; 803 ma[index] = maf[i]; 804 vm_page_flag_clear(ma[index], PG_CLEANCHK); 805 } 806 runlen = maxb + maxf + 1; 807 808 splx(s); 809 vm_pageout_flush(ma, runlen, pagerflags); 810 for (i = 0; i < runlen; i++) { 811 if (ma[i]->valid & ma[i]->dirty) { 812 vm_page_protect(ma[i], VM_PROT_READ); 813 vm_page_flag_set(ma[i], PG_CLEANCHK); 814 815 /* 816 * maxf will end up being the actual number of pages 817 * we wrote out contiguously, non-inclusive of the 818 * first page. We do not count look-behind pages. 819 */ 820 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 821 maxf = i - maxb - 1; 822 } 823 } 824 return(maxf + 1); 825 } 826 827 #ifdef not_used 828 /* XXX I cannot tell if this should be an exported symbol */ 829 /* 830 * vm_object_deactivate_pages 831 * 832 * Deactivate all pages in the specified object. (Keep its pages 833 * in memory even though it is no longer referenced.) 834 * 835 * The object must be locked. 836 */ 837 static void 838 vm_object_deactivate_pages(object) 839 vm_object_t object; 840 { 841 vm_page_t p, next; 842 843 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 844 next = TAILQ_NEXT(p, listq); 845 vm_page_deactivate(p); 846 } 847 } 848 #endif 849 850 /* 851 * Same as vm_object_pmap_copy, except range checking really 852 * works, and is meant for small sections of an object. 853 * 854 * This code protects resident pages by making them read-only 855 * and is typically called on a fork or split when a page 856 * is converted to copy-on-write. 857 * 858 * NOTE: If the page is already at VM_PROT_NONE, calling 859 * vm_page_protect will have no effect. 860 */ 861 862 void 863 vm_object_pmap_copy_1(object, start, end) 864 vm_object_t object; 865 vm_pindex_t start; 866 vm_pindex_t end; 867 { 868 vm_pindex_t idx; 869 vm_page_t p; 870 871 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0) 872 return; 873 874 for (idx = start; idx < end; idx++) { 875 p = vm_page_lookup(object, idx); 876 if (p == NULL) 877 continue; 878 vm_page_protect(p, VM_PROT_READ); 879 } 880 } 881 882 /* 883 * vm_object_pmap_remove: 884 * 885 * Removes all physical pages in the specified 886 * object range from all physical maps. 887 * 888 * The object must *not* be locked. 889 */ 890 void 891 vm_object_pmap_remove(object, start, end) 892 vm_object_t object; 893 vm_pindex_t start; 894 vm_pindex_t end; 895 { 896 vm_page_t p; 897 898 if (object == NULL) 899 return; 900 for (p = TAILQ_FIRST(&object->memq); 901 p != NULL; 902 p = TAILQ_NEXT(p, listq)) { 903 if (p->pindex >= start && p->pindex < end) 904 vm_page_protect(p, VM_PROT_NONE); 905 } 906 if ((start == 0) && (object->size == end)) 907 vm_object_clear_flag(object, OBJ_WRITEABLE); 908 } 909 910 /* 911 * vm_object_madvise: 912 * 913 * Implements the madvise function at the object/page level. 914 * 915 * MADV_WILLNEED (any object) 916 * 917 * Activate the specified pages if they are resident. 918 * 919 * MADV_DONTNEED (any object) 920 * 921 * Deactivate the specified pages if they are resident. 922 * 923 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 924 * OBJ_ONEMAPPING only) 925 * 926 * Deactivate and clean the specified pages if they are 927 * resident. This permits the process to reuse the pages 928 * without faulting or the kernel to reclaim the pages 929 * without I/O. 930 */ 931 void 932 vm_object_madvise(object, pindex, count, advise) 933 vm_object_t object; 934 vm_pindex_t pindex; 935 int count; 936 int advise; 937 { 938 vm_pindex_t end, tpindex; 939 vm_object_t tobject; 940 vm_page_t m; 941 942 if (object == NULL) 943 return; 944 945 end = pindex + count; 946 947 /* 948 * Locate and adjust resident pages 949 */ 950 951 for (; pindex < end; pindex += 1) { 952 relookup: 953 tobject = object; 954 tpindex = pindex; 955 shadowlookup: 956 /* 957 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 958 * and those pages must be OBJ_ONEMAPPING. 959 */ 960 if (advise == MADV_FREE) { 961 if ((tobject->type != OBJT_DEFAULT && 962 tobject->type != OBJT_SWAP) || 963 (tobject->flags & OBJ_ONEMAPPING) == 0) { 964 continue; 965 } 966 } 967 968 m = vm_page_lookup(tobject, tpindex); 969 970 if (m == NULL) { 971 /* 972 * There may be swap even if there is no backing page 973 */ 974 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 975 swap_pager_freespace(tobject, tpindex, 1); 976 977 /* 978 * next object 979 */ 980 tobject = tobject->backing_object; 981 if (tobject == NULL) 982 continue; 983 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 984 goto shadowlookup; 985 } 986 987 /* 988 * If the page is busy or not in a normal active state, 989 * we skip it. If the page is not managed there are no 990 * page queues to mess with. Things can break if we mess 991 * with pages in any of the below states. 992 */ 993 if ( 994 m->hold_count || 995 m->wire_count || 996 (m->flags & PG_UNMANAGED) || 997 m->valid != VM_PAGE_BITS_ALL 998 ) { 999 continue; 1000 } 1001 1002 if (vm_page_sleep_busy(m, TRUE, "madvpo")) 1003 goto relookup; 1004 1005 if (advise == MADV_WILLNEED) { 1006 vm_page_activate(m); 1007 } else if (advise == MADV_DONTNEED) { 1008 vm_page_dontneed(m); 1009 } else if (advise == MADV_FREE) { 1010 /* 1011 * Mark the page clean. This will allow the page 1012 * to be freed up by the system. However, such pages 1013 * are often reused quickly by malloc()/free() 1014 * so we do not do anything that would cause 1015 * a page fault if we can help it. 1016 * 1017 * Specifically, we do not try to actually free 1018 * the page now nor do we try to put it in the 1019 * cache (which would cause a page fault on reuse). 1020 * 1021 * But we do make the page is freeable as we 1022 * can without actually taking the step of unmapping 1023 * it. 1024 */ 1025 pmap_clear_modify(m); 1026 m->dirty = 0; 1027 m->act_count = 0; 1028 vm_page_dontneed(m); 1029 if (tobject->type == OBJT_SWAP) 1030 swap_pager_freespace(tobject, tpindex, 1); 1031 } 1032 } 1033 } 1034 1035 /* 1036 * vm_object_shadow: 1037 * 1038 * Create a new object which is backed by the 1039 * specified existing object range. The source 1040 * object reference is deallocated. 1041 * 1042 * The new object and offset into that object 1043 * are returned in the source parameters. 1044 */ 1045 1046 void 1047 vm_object_shadow(object, offset, length) 1048 vm_object_t *object; /* IN/OUT */ 1049 vm_ooffset_t *offset; /* IN/OUT */ 1050 vm_size_t length; 1051 { 1052 vm_object_t source; 1053 vm_object_t result; 1054 1055 source = *object; 1056 1057 /* 1058 * Don't create the new object if the old object isn't shared. 1059 */ 1060 1061 if (source != NULL && 1062 source->ref_count == 1 && 1063 source->handle == NULL && 1064 (source->type == OBJT_DEFAULT || 1065 source->type == OBJT_SWAP)) 1066 return; 1067 1068 /* 1069 * Allocate a new object with the given length 1070 */ 1071 1072 if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL) 1073 panic("vm_object_shadow: no object for shadowing"); 1074 1075 /* 1076 * The new object shadows the source object, adding a reference to it. 1077 * Our caller changes his reference to point to the new object, 1078 * removing a reference to the source object. Net result: no change 1079 * of reference count. 1080 * 1081 * Try to optimize the result object's page color when shadowing 1082 * in order to maintain page coloring consistency in the combined 1083 * shadowed object. 1084 */ 1085 result->backing_object = source; 1086 if (source) { 1087 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1088 source->shadow_count++; 1089 source->generation++; 1090 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK; 1091 } 1092 1093 /* 1094 * Store the offset into the source object, and fix up the offset into 1095 * the new object. 1096 */ 1097 1098 result->backing_object_offset = *offset; 1099 1100 /* 1101 * Return the new things 1102 */ 1103 1104 *offset = 0; 1105 *object = result; 1106 } 1107 1108 #define OBSC_TEST_ALL_SHADOWED 0x0001 1109 #define OBSC_COLLAPSE_NOWAIT 0x0002 1110 #define OBSC_COLLAPSE_WAIT 0x0004 1111 1112 static __inline int 1113 vm_object_backing_scan(vm_object_t object, int op) 1114 { 1115 int s; 1116 int r = 1; 1117 vm_page_t p; 1118 vm_object_t backing_object; 1119 vm_pindex_t backing_offset_index; 1120 1121 s = splvm(); 1122 1123 backing_object = object->backing_object; 1124 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1125 1126 /* 1127 * Initial conditions 1128 */ 1129 1130 if (op & OBSC_TEST_ALL_SHADOWED) { 1131 /* 1132 * We do not want to have to test for the existence of 1133 * swap pages in the backing object. XXX but with the 1134 * new swapper this would be pretty easy to do. 1135 * 1136 * XXX what about anonymous MAP_SHARED memory that hasn't 1137 * been ZFOD faulted yet? If we do not test for this, the 1138 * shadow test may succeed! XXX 1139 */ 1140 if (backing_object->type != OBJT_DEFAULT) { 1141 splx(s); 1142 return(0); 1143 } 1144 } 1145 if (op & OBSC_COLLAPSE_WAIT) { 1146 vm_object_set_flag(backing_object, OBJ_DEAD); 1147 } 1148 1149 /* 1150 * Our scan 1151 */ 1152 1153 p = TAILQ_FIRST(&backing_object->memq); 1154 while (p) { 1155 vm_page_t next = TAILQ_NEXT(p, listq); 1156 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1157 1158 if (op & OBSC_TEST_ALL_SHADOWED) { 1159 vm_page_t pp; 1160 1161 /* 1162 * Ignore pages outside the parent object's range 1163 * and outside the parent object's mapping of the 1164 * backing object. 1165 * 1166 * note that we do not busy the backing object's 1167 * page. 1168 */ 1169 1170 if ( 1171 p->pindex < backing_offset_index || 1172 new_pindex >= object->size 1173 ) { 1174 p = next; 1175 continue; 1176 } 1177 1178 /* 1179 * See if the parent has the page or if the parent's 1180 * object pager has the page. If the parent has the 1181 * page but the page is not valid, the parent's 1182 * object pager must have the page. 1183 * 1184 * If this fails, the parent does not completely shadow 1185 * the object and we might as well give up now. 1186 */ 1187 1188 pp = vm_page_lookup(object, new_pindex); 1189 if ( 1190 (pp == NULL || pp->valid == 0) && 1191 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1192 ) { 1193 r = 0; 1194 break; 1195 } 1196 } 1197 1198 /* 1199 * Check for busy page 1200 */ 1201 1202 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1203 vm_page_t pp; 1204 1205 if (op & OBSC_COLLAPSE_NOWAIT) { 1206 if ( 1207 (p->flags & PG_BUSY) || 1208 !p->valid || 1209 p->hold_count || 1210 p->wire_count || 1211 p->busy 1212 ) { 1213 p = next; 1214 continue; 1215 } 1216 } else if (op & OBSC_COLLAPSE_WAIT) { 1217 if (vm_page_sleep_busy(p, TRUE, "vmocol")) { 1218 /* 1219 * If we slept, anything could have 1220 * happened. Since the object is 1221 * marked dead, the backing offset 1222 * should not have changed so we 1223 * just restart our scan. 1224 */ 1225 p = TAILQ_FIRST(&backing_object->memq); 1226 continue; 1227 } 1228 } 1229 1230 /* 1231 * Busy the page 1232 */ 1233 vm_page_busy(p); 1234 1235 KASSERT( 1236 p->object == backing_object, 1237 ("vm_object_qcollapse(): object mismatch") 1238 ); 1239 1240 /* 1241 * Destroy any associated swap 1242 */ 1243 if (backing_object->type == OBJT_SWAP) { 1244 swap_pager_freespace( 1245 backing_object, 1246 p->pindex, 1247 1 1248 ); 1249 } 1250 1251 if ( 1252 p->pindex < backing_offset_index || 1253 new_pindex >= object->size 1254 ) { 1255 /* 1256 * Page is out of the parent object's range, we 1257 * can simply destroy it. 1258 */ 1259 vm_page_protect(p, VM_PROT_NONE); 1260 vm_page_free(p); 1261 p = next; 1262 continue; 1263 } 1264 1265 pp = vm_page_lookup(object, new_pindex); 1266 if ( 1267 pp != NULL || 1268 vm_pager_has_page(object, new_pindex, NULL, NULL) 1269 ) { 1270 /* 1271 * page already exists in parent OR swap exists 1272 * for this location in the parent. Destroy 1273 * the original page from the backing object. 1274 * 1275 * Leave the parent's page alone 1276 */ 1277 vm_page_protect(p, VM_PROT_NONE); 1278 vm_page_free(p); 1279 p = next; 1280 continue; 1281 } 1282 1283 /* 1284 * Page does not exist in parent, rename the 1285 * page from the backing object to the main object. 1286 * 1287 * If the page was mapped to a process, it can remain 1288 * mapped through the rename. 1289 */ 1290 if ((p->queue - p->pc) == PQ_CACHE) 1291 vm_page_deactivate(p); 1292 1293 vm_page_rename(p, object, new_pindex); 1294 /* page automatically made dirty by rename */ 1295 } 1296 p = next; 1297 } 1298 splx(s); 1299 return(r); 1300 } 1301 1302 1303 /* 1304 * this version of collapse allows the operation to occur earlier and 1305 * when paging_in_progress is true for an object... This is not a complete 1306 * operation, but should plug 99.9% of the rest of the leaks. 1307 */ 1308 static void 1309 vm_object_qcollapse(object) 1310 vm_object_t object; 1311 { 1312 vm_object_t backing_object = object->backing_object; 1313 1314 if (backing_object->ref_count != 1) 1315 return; 1316 1317 backing_object->ref_count += 2; 1318 1319 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1320 1321 backing_object->ref_count -= 2; 1322 } 1323 1324 /* 1325 * vm_object_collapse: 1326 * 1327 * Collapse an object with the object backing it. 1328 * Pages in the backing object are moved into the 1329 * parent, and the backing object is deallocated. 1330 */ 1331 void 1332 vm_object_collapse(object) 1333 vm_object_t object; 1334 { 1335 while (TRUE) { 1336 vm_object_t backing_object; 1337 1338 /* 1339 * Verify that the conditions are right for collapse: 1340 * 1341 * The object exists and the backing object exists. 1342 */ 1343 if (object == NULL) 1344 break; 1345 1346 if ((backing_object = object->backing_object) == NULL) 1347 break; 1348 1349 /* 1350 * we check the backing object first, because it is most likely 1351 * not collapsable. 1352 */ 1353 if (backing_object->handle != NULL || 1354 (backing_object->type != OBJT_DEFAULT && 1355 backing_object->type != OBJT_SWAP) || 1356 (backing_object->flags & OBJ_DEAD) || 1357 object->handle != NULL || 1358 (object->type != OBJT_DEFAULT && 1359 object->type != OBJT_SWAP) || 1360 (object->flags & OBJ_DEAD)) { 1361 break; 1362 } 1363 1364 if ( 1365 object->paging_in_progress != 0 || 1366 backing_object->paging_in_progress != 0 1367 ) { 1368 vm_object_qcollapse(object); 1369 break; 1370 } 1371 1372 /* 1373 * We know that we can either collapse the backing object (if 1374 * the parent is the only reference to it) or (perhaps) have 1375 * the parent bypass the object if the parent happens to shadow 1376 * all the resident pages in the entire backing object. 1377 * 1378 * This is ignoring pager-backed pages such as swap pages. 1379 * vm_object_backing_scan fails the shadowing test in this 1380 * case. 1381 */ 1382 1383 if (backing_object->ref_count == 1) { 1384 /* 1385 * If there is exactly one reference to the backing 1386 * object, we can collapse it into the parent. 1387 */ 1388 1389 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1390 1391 /* 1392 * Move the pager from backing_object to object. 1393 */ 1394 1395 if (backing_object->type == OBJT_SWAP) { 1396 vm_object_pip_add(backing_object, 1); 1397 1398 /* 1399 * scrap the paging_offset junk and do a 1400 * discrete copy. This also removes major 1401 * assumptions about how the swap-pager 1402 * works from where it doesn't belong. The 1403 * new swapper is able to optimize the 1404 * destroy-source case. 1405 */ 1406 1407 vm_object_pip_add(object, 1); 1408 swap_pager_copy( 1409 backing_object, 1410 object, 1411 OFF_TO_IDX(object->backing_object_offset), TRUE); 1412 vm_object_pip_wakeup(object); 1413 1414 vm_object_pip_wakeup(backing_object); 1415 } 1416 /* 1417 * Object now shadows whatever backing_object did. 1418 * Note that the reference to 1419 * backing_object->backing_object moves from within 1420 * backing_object to within object. 1421 */ 1422 1423 LIST_REMOVE(object, shadow_list); 1424 object->backing_object->shadow_count--; 1425 object->backing_object->generation++; 1426 if (backing_object->backing_object) { 1427 LIST_REMOVE(backing_object, shadow_list); 1428 backing_object->backing_object->shadow_count--; 1429 backing_object->backing_object->generation++; 1430 } 1431 object->backing_object = backing_object->backing_object; 1432 if (object->backing_object) { 1433 LIST_INSERT_HEAD( 1434 &object->backing_object->shadow_head, 1435 object, 1436 shadow_list 1437 ); 1438 object->backing_object->shadow_count++; 1439 object->backing_object->generation++; 1440 } 1441 1442 object->backing_object_offset += 1443 backing_object->backing_object_offset; 1444 1445 /* 1446 * Discard backing_object. 1447 * 1448 * Since the backing object has no pages, no pager left, 1449 * and no object references within it, all that is 1450 * necessary is to dispose of it. 1451 */ 1452 1453 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1454 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object)); 1455 TAILQ_REMOVE( 1456 &vm_object_list, 1457 backing_object, 1458 object_list 1459 ); 1460 vm_object_count--; 1461 1462 zfree(obj_zone, backing_object); 1463 1464 object_collapses++; 1465 } else { 1466 vm_object_t new_backing_object; 1467 1468 /* 1469 * If we do not entirely shadow the backing object, 1470 * there is nothing we can do so we give up. 1471 */ 1472 1473 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1474 break; 1475 } 1476 1477 /* 1478 * Make the parent shadow the next object in the 1479 * chain. Deallocating backing_object will not remove 1480 * it, since its reference count is at least 2. 1481 */ 1482 1483 LIST_REMOVE(object, shadow_list); 1484 backing_object->shadow_count--; 1485 backing_object->generation++; 1486 1487 new_backing_object = backing_object->backing_object; 1488 if ((object->backing_object = new_backing_object) != NULL) { 1489 vm_object_reference(new_backing_object); 1490 LIST_INSERT_HEAD( 1491 &new_backing_object->shadow_head, 1492 object, 1493 shadow_list 1494 ); 1495 new_backing_object->shadow_count++; 1496 new_backing_object->generation++; 1497 object->backing_object_offset += 1498 backing_object->backing_object_offset; 1499 } 1500 1501 /* 1502 * Drop the reference count on backing_object. Since 1503 * its ref_count was at least 2, it will not vanish; 1504 * so we don't need to call vm_object_deallocate, but 1505 * we do anyway. 1506 */ 1507 vm_object_deallocate(backing_object); 1508 object_bypasses++; 1509 } 1510 1511 /* 1512 * Try again with this object's new backing object. 1513 */ 1514 } 1515 } 1516 1517 /* 1518 * vm_object_page_remove: [internal] 1519 * 1520 * Removes all physical pages in the specified 1521 * object range from the object's list of pages. 1522 * 1523 * The object must be locked. 1524 */ 1525 void 1526 vm_object_page_remove(object, start, end, clean_only) 1527 vm_object_t object; 1528 vm_pindex_t start; 1529 vm_pindex_t end; 1530 boolean_t clean_only; 1531 { 1532 vm_page_t p, next; 1533 unsigned int size; 1534 int all; 1535 1536 if (object == NULL || 1537 object->resident_page_count == 0) 1538 return; 1539 1540 all = ((end == 0) && (start == 0)); 1541 1542 /* 1543 * Since physically-backed objects do not use managed pages, we can't 1544 * remove pages from the object (we must instead remove the page 1545 * references, and then destroy the object). 1546 */ 1547 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object")); 1548 1549 vm_object_pip_add(object, 1); 1550 again: 1551 size = end - start; 1552 if (all || size > object->resident_page_count / 4) { 1553 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 1554 next = TAILQ_NEXT(p, listq); 1555 if (all || ((start <= p->pindex) && (p->pindex < end))) { 1556 if (p->wire_count != 0) { 1557 vm_page_protect(p, VM_PROT_NONE); 1558 if (!clean_only) 1559 p->valid = 0; 1560 continue; 1561 } 1562 1563 /* 1564 * The busy flags are only cleared at 1565 * interrupt -- minimize the spl transitions 1566 */ 1567 1568 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1569 goto again; 1570 1571 if (clean_only && p->valid) { 1572 vm_page_test_dirty(p); 1573 if (p->valid & p->dirty) 1574 continue; 1575 } 1576 1577 vm_page_busy(p); 1578 vm_page_protect(p, VM_PROT_NONE); 1579 vm_page_free(p); 1580 } 1581 } 1582 } else { 1583 while (size > 0) { 1584 if ((p = vm_page_lookup(object, start)) != 0) { 1585 1586 if (p->wire_count != 0) { 1587 vm_page_protect(p, VM_PROT_NONE); 1588 if (!clean_only) 1589 p->valid = 0; 1590 start += 1; 1591 size -= 1; 1592 continue; 1593 } 1594 1595 /* 1596 * The busy flags are only cleared at 1597 * interrupt -- minimize the spl transitions 1598 */ 1599 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1600 goto again; 1601 1602 if (clean_only && p->valid) { 1603 vm_page_test_dirty(p); 1604 if (p->valid & p->dirty) { 1605 start += 1; 1606 size -= 1; 1607 continue; 1608 } 1609 } 1610 1611 vm_page_busy(p); 1612 vm_page_protect(p, VM_PROT_NONE); 1613 vm_page_free(p); 1614 } 1615 start += 1; 1616 size -= 1; 1617 } 1618 } 1619 vm_object_pip_wakeup(object); 1620 } 1621 1622 /* 1623 * Routine: vm_object_coalesce 1624 * Function: Coalesces two objects backing up adjoining 1625 * regions of memory into a single object. 1626 * 1627 * returns TRUE if objects were combined. 1628 * 1629 * NOTE: Only works at the moment if the second object is NULL - 1630 * if it's not, which object do we lock first? 1631 * 1632 * Parameters: 1633 * prev_object First object to coalesce 1634 * prev_offset Offset into prev_object 1635 * next_object Second object into coalesce 1636 * next_offset Offset into next_object 1637 * 1638 * prev_size Size of reference to prev_object 1639 * next_size Size of reference to next_object 1640 * 1641 * Conditions: 1642 * The object must *not* be locked. 1643 */ 1644 boolean_t 1645 vm_object_coalesce(prev_object, prev_pindex, prev_size, next_size) 1646 vm_object_t prev_object; 1647 vm_pindex_t prev_pindex; 1648 vm_size_t prev_size, next_size; 1649 { 1650 vm_pindex_t next_pindex; 1651 1652 if (prev_object == NULL) { 1653 return (TRUE); 1654 } 1655 1656 if (prev_object->type != OBJT_DEFAULT && 1657 prev_object->type != OBJT_SWAP) { 1658 return (FALSE); 1659 } 1660 1661 /* 1662 * Try to collapse the object first 1663 */ 1664 vm_object_collapse(prev_object); 1665 1666 /* 1667 * Can't coalesce if: . more than one reference . paged out . shadows 1668 * another object . has a copy elsewhere (any of which mean that the 1669 * pages not mapped to prev_entry may be in use anyway) 1670 */ 1671 1672 if (prev_object->backing_object != NULL) { 1673 return (FALSE); 1674 } 1675 1676 prev_size >>= PAGE_SHIFT; 1677 next_size >>= PAGE_SHIFT; 1678 next_pindex = prev_pindex + prev_size; 1679 1680 if ((prev_object->ref_count > 1) && 1681 (prev_object->size != next_pindex)) { 1682 return (FALSE); 1683 } 1684 1685 /* 1686 * Remove any pages that may still be in the object from a previous 1687 * deallocation. 1688 */ 1689 if (next_pindex < prev_object->size) { 1690 vm_object_page_remove(prev_object, 1691 next_pindex, 1692 next_pindex + next_size, FALSE); 1693 if (prev_object->type == OBJT_SWAP) 1694 swap_pager_freespace(prev_object, 1695 next_pindex, next_size); 1696 } 1697 1698 /* 1699 * Extend the object if necessary. 1700 */ 1701 if (next_pindex + next_size > prev_object->size) 1702 prev_object->size = next_pindex + next_size; 1703 1704 return (TRUE); 1705 } 1706 1707 void 1708 vm_object_set_writeable_dirty(vm_object_t object) 1709 { 1710 struct vnode *vp; 1711 lwkt_tokref vlock; 1712 1713 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1714 if (object->type == OBJT_VNODE && 1715 (vp = (struct vnode *)object->handle) != NULL) { 1716 if ((vp->v_flag & VOBJDIRTY) == 0) { 1717 lwkt_gettoken(&vlock, vp->v_interlock); 1718 vp->v_flag |= VOBJDIRTY; 1719 lwkt_reltoken(&vlock); 1720 } 1721 } 1722 } 1723 1724 1725 1726 #include "opt_ddb.h" 1727 #ifdef DDB 1728 #include <sys/kernel.h> 1729 1730 #include <sys/cons.h> 1731 1732 #include <ddb/ddb.h> 1733 1734 static int _vm_object_in_map (vm_map_t map, vm_object_t object, 1735 vm_map_entry_t entry); 1736 static int vm_object_in_map (vm_object_t object); 1737 1738 static int 1739 _vm_object_in_map(map, object, entry) 1740 vm_map_t map; 1741 vm_object_t object; 1742 vm_map_entry_t entry; 1743 { 1744 vm_map_t tmpm; 1745 vm_map_entry_t tmpe; 1746 vm_object_t obj; 1747 int entcount; 1748 1749 if (map == 0) 1750 return 0; 1751 1752 if (entry == 0) { 1753 tmpe = map->header.next; 1754 entcount = map->nentries; 1755 while (entcount-- && (tmpe != &map->header)) { 1756 if( _vm_object_in_map(map, object, tmpe)) { 1757 return 1; 1758 } 1759 tmpe = tmpe->next; 1760 } 1761 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1762 tmpm = entry->object.sub_map; 1763 tmpe = tmpm->header.next; 1764 entcount = tmpm->nentries; 1765 while (entcount-- && tmpe != &tmpm->header) { 1766 if( _vm_object_in_map(tmpm, object, tmpe)) { 1767 return 1; 1768 } 1769 tmpe = tmpe->next; 1770 } 1771 } else if ((obj = entry->object.vm_object) != NULL) { 1772 for(; obj; obj=obj->backing_object) 1773 if( obj == object) { 1774 return 1; 1775 } 1776 } 1777 return 0; 1778 } 1779 1780 static int 1781 vm_object_in_map( object) 1782 vm_object_t object; 1783 { 1784 struct proc *p; 1785 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 1786 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1787 continue; 1788 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) 1789 return 1; 1790 } 1791 if( _vm_object_in_map( kernel_map, object, 0)) 1792 return 1; 1793 if( _vm_object_in_map( pager_map, object, 0)) 1794 return 1; 1795 if( _vm_object_in_map( buffer_map, object, 0)) 1796 return 1; 1797 if( _vm_object_in_map( mb_map, object, 0)) 1798 return 1; 1799 return 0; 1800 } 1801 1802 DB_SHOW_COMMAND(vmochk, vm_object_check) 1803 { 1804 vm_object_t object; 1805 1806 /* 1807 * make sure that internal objs are in a map somewhere 1808 * and none have zero ref counts. 1809 */ 1810 for (object = TAILQ_FIRST(&vm_object_list); 1811 object != NULL; 1812 object = TAILQ_NEXT(object, object_list)) { 1813 if (object->handle == NULL && 1814 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1815 if (object->ref_count == 0) { 1816 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1817 (long)object->size); 1818 } 1819 if (!vm_object_in_map(object)) { 1820 db_printf( 1821 "vmochk: internal obj is not in a map: " 1822 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1823 object->ref_count, (u_long)object->size, 1824 (u_long)object->size, 1825 (void *)object->backing_object); 1826 } 1827 } 1828 } 1829 } 1830 1831 /* 1832 * vm_object_print: [ debug ] 1833 */ 1834 DB_SHOW_COMMAND(object, vm_object_print_static) 1835 { 1836 /* XXX convert args. */ 1837 vm_object_t object = (vm_object_t)addr; 1838 boolean_t full = have_addr; 1839 1840 vm_page_t p; 1841 1842 /* XXX count is an (unused) arg. Avoid shadowing it. */ 1843 #define count was_count 1844 1845 int count; 1846 1847 if (object == NULL) 1848 return; 1849 1850 db_iprintf( 1851 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n", 1852 object, (int)object->type, (u_long)object->size, 1853 object->resident_page_count, object->ref_count, object->flags); 1854 /* 1855 * XXX no %qd in kernel. Truncate object->backing_object_offset. 1856 */ 1857 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n", 1858 object->shadow_count, 1859 object->backing_object ? object->backing_object->ref_count : 0, 1860 object->backing_object, (long)object->backing_object_offset); 1861 1862 if (!full) 1863 return; 1864 1865 db_indent += 2; 1866 count = 0; 1867 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = TAILQ_NEXT(p, listq)) { 1868 if (count == 0) 1869 db_iprintf("memory:="); 1870 else if (count == 6) { 1871 db_printf("\n"); 1872 db_iprintf(" ..."); 1873 count = 0; 1874 } else 1875 db_printf(","); 1876 count++; 1877 1878 db_printf("(off=0x%lx,page=0x%lx)", 1879 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p)); 1880 } 1881 if (count != 0) 1882 db_printf("\n"); 1883 db_indent -= 2; 1884 } 1885 1886 /* XXX. */ 1887 #undef count 1888 1889 /* XXX need this non-static entry for calling from vm_map_print. */ 1890 void 1891 vm_object_print(addr, have_addr, count, modif) 1892 /* db_expr_t */ long addr; 1893 boolean_t have_addr; 1894 /* db_expr_t */ long count; 1895 char *modif; 1896 { 1897 vm_object_print_static(addr, have_addr, count, modif); 1898 } 1899 1900 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 1901 { 1902 vm_object_t object; 1903 int nl = 0; 1904 int c; 1905 for (object = TAILQ_FIRST(&vm_object_list); 1906 object != NULL; 1907 object = TAILQ_NEXT(object, object_list)) { 1908 vm_pindex_t idx, fidx; 1909 vm_pindex_t osize; 1910 vm_paddr_t pa = -1, padiff; 1911 int rcount; 1912 vm_page_t m; 1913 1914 db_printf("new object: %p\n", (void *)object); 1915 if ( nl > 18) { 1916 c = cngetc(); 1917 if (c != ' ') 1918 return; 1919 nl = 0; 1920 } 1921 nl++; 1922 rcount = 0; 1923 fidx = 0; 1924 osize = object->size; 1925 if (osize > 128) 1926 osize = 128; 1927 for(idx=0;idx<osize;idx++) { 1928 m = vm_page_lookup(object, idx); 1929 if (m == NULL) { 1930 if (rcount) { 1931 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1932 (long)fidx, rcount, (long)pa); 1933 if ( nl > 18) { 1934 c = cngetc(); 1935 if (c != ' ') 1936 return; 1937 nl = 0; 1938 } 1939 nl++; 1940 rcount = 0; 1941 } 1942 continue; 1943 } 1944 1945 1946 if (rcount && 1947 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 1948 ++rcount; 1949 continue; 1950 } 1951 if (rcount) { 1952 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 1953 padiff >>= PAGE_SHIFT; 1954 padiff &= PQ_L2_MASK; 1955 if (padiff == 0) { 1956 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 1957 ++rcount; 1958 continue; 1959 } 1960 db_printf(" index(%ld)run(%d)pa(0x%lx)", 1961 (long)fidx, rcount, (long)pa); 1962 db_printf("pd(%ld)\n", (long)padiff); 1963 if ( nl > 18) { 1964 c = cngetc(); 1965 if (c != ' ') 1966 return; 1967 nl = 0; 1968 } 1969 nl++; 1970 } 1971 fidx = idx; 1972 pa = VM_PAGE_TO_PHYS(m); 1973 rcount = 1; 1974 } 1975 if (rcount) { 1976 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1977 (long)fidx, rcount, (long)pa); 1978 if ( nl > 18) { 1979 c = cngetc(); 1980 if (c != ' ') 1981 return; 1982 nl = 0; 1983 } 1984 nl++; 1985 } 1986 } 1987 } 1988 #endif /* DDB */ 1989