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 1.14 2004/03/23 22:54:32 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(objtype_t type, vm_size_t size, vm_object_t object) 153 { 154 int incr; 155 TAILQ_INIT(&object->memq); 156 LIST_INIT(&object->shadow_head); 157 158 object->type = type; 159 object->size = size; 160 object->ref_count = 1; 161 object->flags = 0; 162 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 163 vm_object_set_flag(object, OBJ_ONEMAPPING); 164 object->paging_in_progress = 0; 165 object->resident_page_count = 0; 166 object->shadow_count = 0; 167 object->pg_color = next_index; 168 if ( size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 169 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 170 else 171 incr = size; 172 next_index = (next_index + incr) & PQ_L2_MASK; 173 object->handle = NULL; 174 object->backing_object = NULL; 175 object->backing_object_offset = (vm_ooffset_t) 0; 176 /* 177 * Try to generate a number that will spread objects out in the 178 * hash table. We 'wipe' new objects across the hash in 128 page 179 * increments plus 1 more to offset it a little more by the time 180 * it wraps around. 181 */ 182 object->hash_rand = object_hash_rand - 129; 183 184 object->generation++; 185 186 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 187 vm_object_count++; 188 object_hash_rand = object->hash_rand; 189 } 190 191 /* 192 * vm_object_init: 193 * 194 * Initialize the VM objects module. 195 */ 196 void 197 vm_object_init(void) 198 { 199 TAILQ_INIT(&vm_object_list); 200 lwkt_token_init(&vm_object_list_token); 201 vm_object_count = 0; 202 203 kernel_object = &kernel_object_store; 204 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 205 kernel_object); 206 207 kmem_object = &kmem_object_store; 208 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 209 kmem_object); 210 211 obj_zone = &obj_zone_store; 212 zbootinit(obj_zone, "VM OBJECT", sizeof (struct vm_object), 213 vm_objects_init, VM_OBJECTS_INIT); 214 } 215 216 void 217 vm_object_init2(void) 218 { 219 zinitna(obj_zone, NULL, NULL, 0, 0, ZONE_PANICFAIL, 1); 220 } 221 222 /* 223 * vm_object_allocate: 224 * 225 * Returns a new object with the given size. 226 */ 227 228 vm_object_t 229 vm_object_allocate(objtype_t type, vm_size_t size) 230 { 231 vm_object_t result; 232 233 result = (vm_object_t) zalloc(obj_zone); 234 235 _vm_object_allocate(type, size, result); 236 237 return (result); 238 } 239 240 241 /* 242 * vm_object_reference: 243 * 244 * Gets another reference to the given object. 245 */ 246 void 247 vm_object_reference(vm_object_t object) 248 { 249 if (object == NULL) 250 return; 251 252 #if 0 253 /* object can be re-referenced during final cleaning */ 254 KASSERT(!(object->flags & OBJ_DEAD), 255 ("vm_object_reference: attempting to reference dead obj")); 256 #endif 257 258 object->ref_count++; 259 if (object->type == OBJT_VNODE) { 260 while (vget((struct vnode *) object->handle, NULL, 261 LK_RETRY|LK_NOOBJ, curthread)) { 262 printf("vm_object_reference: delay in getting object\n"); 263 } 264 } 265 } 266 267 void 268 vm_object_vndeallocate(vm_object_t object) 269 { 270 struct vnode *vp = (struct vnode *) object->handle; 271 272 KASSERT(object->type == OBJT_VNODE, 273 ("vm_object_vndeallocate: not a vnode object")); 274 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 275 #ifdef INVARIANTS 276 if (object->ref_count == 0) { 277 vprint("vm_object_vndeallocate", vp); 278 panic("vm_object_vndeallocate: bad object reference count"); 279 } 280 #endif 281 282 object->ref_count--; 283 if (object->ref_count == 0) { 284 vp->v_flag &= ~VTEXT; 285 vm_object_clear_flag(object, OBJ_OPT); 286 } 287 vrele(vp); 288 } 289 290 /* 291 * vm_object_deallocate: 292 * 293 * Release a reference to the specified object, 294 * gained either through a vm_object_allocate 295 * or a vm_object_reference call. When all references 296 * are gone, storage associated with this object 297 * may be relinquished. 298 * 299 * No object may be locked. 300 */ 301 void 302 vm_object_deallocate(vm_object_t object) 303 { 304 vm_object_t temp; 305 306 while (object != NULL) { 307 308 if (object->type == OBJT_VNODE) { 309 vm_object_vndeallocate(object); 310 return; 311 } 312 313 if (object->ref_count == 0) { 314 panic("vm_object_deallocate: object deallocated too many times: %d", object->type); 315 } else if (object->ref_count > 2) { 316 object->ref_count--; 317 return; 318 } 319 320 /* 321 * Here on ref_count of one or two, which are special cases for 322 * objects. 323 */ 324 if ((object->ref_count == 2) && (object->shadow_count == 0)) { 325 vm_object_set_flag(object, OBJ_ONEMAPPING); 326 object->ref_count--; 327 return; 328 } else if ((object->ref_count == 2) && (object->shadow_count == 1)) { 329 object->ref_count--; 330 if ((object->handle == NULL) && 331 (object->type == OBJT_DEFAULT || 332 object->type == OBJT_SWAP)) { 333 vm_object_t robject; 334 335 robject = LIST_FIRST(&object->shadow_head); 336 KASSERT(robject != NULL, 337 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 338 object->ref_count, 339 object->shadow_count)); 340 if ((robject->handle == NULL) && 341 (robject->type == OBJT_DEFAULT || 342 robject->type == OBJT_SWAP)) { 343 344 robject->ref_count++; 345 346 while ( 347 robject->paging_in_progress || 348 object->paging_in_progress 349 ) { 350 vm_object_pip_sleep(robject, "objde1"); 351 vm_object_pip_sleep(object, "objde2"); 352 } 353 354 if (robject->ref_count == 1) { 355 robject->ref_count--; 356 object = robject; 357 goto doterm; 358 } 359 360 object = robject; 361 vm_object_collapse(object); 362 continue; 363 } 364 } 365 366 return; 367 368 } else { 369 object->ref_count--; 370 if (object->ref_count != 0) 371 return; 372 } 373 374 doterm: 375 376 temp = object->backing_object; 377 if (temp) { 378 LIST_REMOVE(object, shadow_list); 379 temp->shadow_count--; 380 if (temp->ref_count == 0) 381 vm_object_clear_flag(temp, OBJ_OPT); 382 temp->generation++; 383 object->backing_object = NULL; 384 } 385 386 /* 387 * Don't double-terminate, we could be in a termination 388 * recursion due to the terminate having to sync data 389 * to disk. 390 */ 391 if ((object->flags & OBJ_DEAD) == 0) 392 vm_object_terminate(object); 393 object = temp; 394 } 395 } 396 397 /* 398 * vm_object_terminate actually destroys the specified object, freeing 399 * up all previously used resources. 400 * 401 * The object must be locked. 402 * This routine may block. 403 */ 404 void 405 vm_object_terminate(vm_object_t object) 406 { 407 lwkt_tokref ilock; 408 vm_page_t p; 409 int s; 410 411 /* 412 * Make sure no one uses us. 413 */ 414 vm_object_set_flag(object, OBJ_DEAD); 415 416 /* 417 * wait for the pageout daemon to be done with the object 418 */ 419 vm_object_pip_wait(object, "objtrm"); 420 421 KASSERT(!object->paging_in_progress, 422 ("vm_object_terminate: pageout in progress")); 423 424 /* 425 * Clean and free the pages, as appropriate. All references to the 426 * object are gone, so we don't need to lock it. 427 */ 428 if (object->type == OBJT_VNODE) { 429 struct vnode *vp; 430 431 /* 432 * Freeze optimized copies. 433 */ 434 vm_freeze_copyopts(object, 0, object->size); 435 436 /* 437 * Clean pages and flush buffers. 438 */ 439 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 440 441 vp = (struct vnode *) object->handle; 442 vinvalbuf(vp, V_SAVE, NULL, 0, 0); 443 } 444 445 /* 446 * Wait for any I/O to complete, after which there had better not 447 * be any references left on the object. 448 */ 449 vm_object_pip_wait(object, "objtrm"); 450 451 if (object->ref_count != 0) 452 panic("vm_object_terminate: object with references, ref_count=%d", object->ref_count); 453 454 /* 455 * Now free any remaining pages. For internal objects, this also 456 * removes them from paging queues. Don't free wired pages, just 457 * remove them from the object. 458 */ 459 s = splvm(); 460 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 461 if (p->busy || (p->flags & PG_BUSY)) 462 panic("vm_object_terminate: freeing busy page %p\n", p); 463 if (p->wire_count == 0) { 464 vm_page_busy(p); 465 vm_page_free(p); 466 mycpu->gd_cnt.v_pfree++; 467 } else { 468 vm_page_busy(p); 469 vm_page_remove(p); 470 } 471 } 472 splx(s); 473 474 /* 475 * Let the pager know object is dead. 476 */ 477 vm_pager_deallocate(object); 478 479 /* 480 * Remove the object from the global object list. 481 */ 482 lwkt_gettoken(&ilock, &vm_object_list_token); 483 TAILQ_REMOVE(&vm_object_list, object, object_list); 484 lwkt_reltoken(&ilock); 485 486 wakeup(object); 487 488 /* 489 * Free the space for the object. 490 */ 491 zfree(obj_zone, object); 492 } 493 494 /* 495 * vm_object_page_clean 496 * 497 * Clean all dirty pages in the specified range of object. Leaves page 498 * on whatever queue it is currently on. If NOSYNC is set then do not 499 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 500 * leaving the object dirty. 501 * 502 * When stuffing pages asynchronously, allow clustering. XXX we need a 503 * synchronous clustering mode implementation. 504 * 505 * Odd semantics: if start == end, we clean everything. 506 * 507 * The object must be locked. 508 */ 509 510 void 511 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 512 int flags) 513 { 514 vm_page_t p, np; 515 vm_offset_t tstart, tend; 516 vm_pindex_t pi; 517 struct vnode *vp; 518 int clearobjflags; 519 int pagerflags; 520 int curgeneration; 521 lwkt_tokref vlock; 522 523 if (object->type != OBJT_VNODE || 524 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 525 return; 526 527 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 528 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 529 530 vp = object->handle; 531 532 vm_object_set_flag(object, OBJ_CLEANING); 533 534 /* 535 * Handle 'entire object' case 536 */ 537 tstart = start; 538 if (end == 0) { 539 tend = object->size; 540 } else { 541 tend = end; 542 } 543 544 /* 545 * If the caller is smart and only msync()s a range he knows is 546 * dirty, we may be able to avoid an object scan. This results in 547 * a phenominal improvement in performance. We cannot do this 548 * as a matter of course because the object may be huge - e.g. 549 * the size might be in the gigabytes or terrabytes. 550 */ 551 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 552 vm_offset_t tscan; 553 int scanlimit; 554 int scanreset; 555 556 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 557 if (scanreset < 16) 558 scanreset = 16; 559 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 560 561 scanlimit = scanreset; 562 tscan = tstart; 563 while (tscan < tend) { 564 curgeneration = object->generation; 565 p = vm_page_lookup(object, tscan); 566 if (p == NULL || p->valid == 0 || 567 (p->queue - p->pc) == PQ_CACHE) { 568 if (--scanlimit == 0) 569 break; 570 ++tscan; 571 continue; 572 } 573 vm_page_test_dirty(p); 574 if ((p->dirty & p->valid) == 0) { 575 if (--scanlimit == 0) 576 break; 577 ++tscan; 578 continue; 579 } 580 /* 581 * If we have been asked to skip nosync pages and 582 * this is a nosync page, we can't continue. 583 */ 584 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 585 if (--scanlimit == 0) 586 break; 587 ++tscan; 588 continue; 589 } 590 scanlimit = scanreset; 591 592 /* 593 * This returns 0 if it was unable to busy the first 594 * page (i.e. had to sleep). 595 */ 596 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 597 } 598 599 /* 600 * If everything was dirty and we flushed it successfully, 601 * and the requested range is not the entire object, we 602 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 603 * return immediately. 604 */ 605 if (tscan >= tend && (tstart || tend < object->size)) { 606 vm_object_clear_flag(object, OBJ_CLEANING); 607 return; 608 } 609 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 610 } 611 612 /* 613 * Generally set CLEANCHK interlock and make the page read-only so 614 * we can then clear the object flags. 615 * 616 * However, if this is a nosync mmap then the object is likely to 617 * stay dirty so do not mess with the page and do not clear the 618 * object flags. 619 */ 620 621 clearobjflags = 1; 622 623 for(p = TAILQ_FIRST(&object->memq); p; p = TAILQ_NEXT(p, listq)) { 624 vm_page_flag_set(p, PG_CLEANCHK); 625 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 626 clearobjflags = 0; 627 else 628 vm_page_protect(p, VM_PROT_READ); 629 } 630 631 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 632 struct vnode *vp; 633 634 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 635 if (object->type == OBJT_VNODE && 636 (vp = (struct vnode *)object->handle) != NULL) { 637 if (vp->v_flag & VOBJDIRTY) { 638 lwkt_gettoken(&vlock, vp->v_interlock); 639 vp->v_flag &= ~VOBJDIRTY; 640 lwkt_reltoken(&vlock); 641 } 642 } 643 } 644 645 rescan: 646 curgeneration = object->generation; 647 648 for(p = TAILQ_FIRST(&object->memq); p; p = np) { 649 int n; 650 651 np = TAILQ_NEXT(p, listq); 652 653 again: 654 pi = p->pindex; 655 if (((p->flags & PG_CLEANCHK) == 0) || 656 (pi < tstart) || (pi >= tend) || 657 (p->valid == 0) || 658 ((p->queue - p->pc) == PQ_CACHE)) { 659 vm_page_flag_clear(p, PG_CLEANCHK); 660 continue; 661 } 662 663 vm_page_test_dirty(p); 664 if ((p->dirty & p->valid) == 0) { 665 vm_page_flag_clear(p, PG_CLEANCHK); 666 continue; 667 } 668 669 /* 670 * If we have been asked to skip nosync pages and this is a 671 * nosync page, skip it. Note that the object flags were 672 * not cleared in this case so we do not have to set them. 673 */ 674 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 675 vm_page_flag_clear(p, PG_CLEANCHK); 676 continue; 677 } 678 679 n = vm_object_page_collect_flush(object, p, 680 curgeneration, pagerflags); 681 if (n == 0) 682 goto rescan; 683 if (object->generation != curgeneration) 684 goto rescan; 685 686 /* 687 * Try to optimize the next page. If we can't we pick up 688 * our (random) scan where we left off. 689 */ 690 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 691 if ((p = vm_page_lookup(object, pi + n)) != NULL) 692 goto again; 693 } 694 } 695 696 #if 0 697 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 698 #endif 699 700 vm_object_clear_flag(object, OBJ_CLEANING); 701 return; 702 } 703 704 static int 705 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 706 { 707 int runlen; 708 int s; 709 int maxf; 710 int chkb; 711 int maxb; 712 int i; 713 vm_pindex_t pi; 714 vm_page_t maf[vm_pageout_page_count]; 715 vm_page_t mab[vm_pageout_page_count]; 716 vm_page_t ma[vm_pageout_page_count]; 717 718 s = splvm(); 719 pi = p->pindex; 720 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) { 721 if (object->generation != curgeneration) { 722 splx(s); 723 return(0); 724 } 725 } 726 727 maxf = 0; 728 for(i = 1; i < vm_pageout_page_count; i++) { 729 vm_page_t tp; 730 731 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 732 if ((tp->flags & PG_BUSY) || 733 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 734 (tp->flags & PG_CLEANCHK) == 0) || 735 (tp->busy != 0)) 736 break; 737 if((tp->queue - tp->pc) == PQ_CACHE) { 738 vm_page_flag_clear(tp, PG_CLEANCHK); 739 break; 740 } 741 vm_page_test_dirty(tp); 742 if ((tp->dirty & tp->valid) == 0) { 743 vm_page_flag_clear(tp, PG_CLEANCHK); 744 break; 745 } 746 maf[ i - 1 ] = tp; 747 maxf++; 748 continue; 749 } 750 break; 751 } 752 753 maxb = 0; 754 chkb = vm_pageout_page_count - maxf; 755 if (chkb) { 756 for(i = 1; i < chkb;i++) { 757 vm_page_t tp; 758 759 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 760 if ((tp->flags & PG_BUSY) || 761 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 762 (tp->flags & PG_CLEANCHK) == 0) || 763 (tp->busy != 0)) 764 break; 765 if((tp->queue - tp->pc) == PQ_CACHE) { 766 vm_page_flag_clear(tp, PG_CLEANCHK); 767 break; 768 } 769 vm_page_test_dirty(tp); 770 if ((tp->dirty & tp->valid) == 0) { 771 vm_page_flag_clear(tp, PG_CLEANCHK); 772 break; 773 } 774 mab[ i - 1 ] = tp; 775 maxb++; 776 continue; 777 } 778 break; 779 } 780 } 781 782 for(i = 0; i < maxb; i++) { 783 int index = (maxb - i) - 1; 784 ma[index] = mab[i]; 785 vm_page_flag_clear(ma[index], PG_CLEANCHK); 786 } 787 vm_page_flag_clear(p, PG_CLEANCHK); 788 ma[maxb] = p; 789 for(i = 0; i < maxf; i++) { 790 int index = (maxb + i) + 1; 791 ma[index] = maf[i]; 792 vm_page_flag_clear(ma[index], PG_CLEANCHK); 793 } 794 runlen = maxb + maxf + 1; 795 796 splx(s); 797 vm_pageout_flush(ma, runlen, pagerflags); 798 for (i = 0; i < runlen; i++) { 799 if (ma[i]->valid & ma[i]->dirty) { 800 vm_page_protect(ma[i], VM_PROT_READ); 801 vm_page_flag_set(ma[i], PG_CLEANCHK); 802 803 /* 804 * maxf will end up being the actual number of pages 805 * we wrote out contiguously, non-inclusive of the 806 * first page. We do not count look-behind pages. 807 */ 808 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 809 maxf = i - maxb - 1; 810 } 811 } 812 return(maxf + 1); 813 } 814 815 #ifdef not_used 816 /* XXX I cannot tell if this should be an exported symbol */ 817 /* 818 * vm_object_deactivate_pages 819 * 820 * Deactivate all pages in the specified object. (Keep its pages 821 * in memory even though it is no longer referenced.) 822 * 823 * The object must be locked. 824 */ 825 static void 826 vm_object_deactivate_pages(vm_object_t object) 827 { 828 vm_page_t p, next; 829 830 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 831 next = TAILQ_NEXT(p, listq); 832 vm_page_deactivate(p); 833 } 834 } 835 #endif 836 837 /* 838 * Same as vm_object_pmap_copy, except range checking really 839 * works, and is meant for small sections of an object. 840 * 841 * This code protects resident pages by making them read-only 842 * and is typically called on a fork or split when a page 843 * is converted to copy-on-write. 844 * 845 * NOTE: If the page is already at VM_PROT_NONE, calling 846 * vm_page_protect will have no effect. 847 */ 848 849 void 850 vm_object_pmap_copy_1(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 851 { 852 vm_pindex_t idx; 853 vm_page_t p; 854 855 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0) 856 return; 857 858 for (idx = start; idx < end; idx++) { 859 p = vm_page_lookup(object, idx); 860 if (p == NULL) 861 continue; 862 vm_page_protect(p, VM_PROT_READ); 863 } 864 } 865 866 /* 867 * vm_object_pmap_remove: 868 * 869 * Removes all physical pages in the specified 870 * object range from all physical maps. 871 * 872 * The object must *not* be locked. 873 */ 874 void 875 vm_object_pmap_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 876 { 877 vm_page_t p; 878 879 if (object == NULL) 880 return; 881 for (p = TAILQ_FIRST(&object->memq); 882 p != NULL; 883 p = TAILQ_NEXT(p, listq)) { 884 if (p->pindex >= start && p->pindex < end) 885 vm_page_protect(p, VM_PROT_NONE); 886 } 887 if ((start == 0) && (object->size == end)) 888 vm_object_clear_flag(object, OBJ_WRITEABLE); 889 } 890 891 /* 892 * vm_object_madvise: 893 * 894 * Implements the madvise function at the object/page level. 895 * 896 * MADV_WILLNEED (any object) 897 * 898 * Activate the specified pages if they are resident. 899 * 900 * MADV_DONTNEED (any object) 901 * 902 * Deactivate the specified pages if they are resident. 903 * 904 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 905 * OBJ_ONEMAPPING only) 906 * 907 * Deactivate and clean the specified pages if they are 908 * resident. This permits the process to reuse the pages 909 * without faulting or the kernel to reclaim the pages 910 * without I/O. 911 */ 912 void 913 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 914 { 915 vm_pindex_t end, tpindex; 916 vm_object_t tobject; 917 vm_page_t m; 918 919 if (object == NULL) 920 return; 921 922 end = pindex + count; 923 924 /* 925 * Locate and adjust resident pages 926 */ 927 928 for (; pindex < end; pindex += 1) { 929 relookup: 930 tobject = object; 931 tpindex = pindex; 932 shadowlookup: 933 /* 934 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 935 * and those pages must be OBJ_ONEMAPPING. 936 */ 937 if (advise == MADV_FREE) { 938 if ((tobject->type != OBJT_DEFAULT && 939 tobject->type != OBJT_SWAP) || 940 (tobject->flags & OBJ_ONEMAPPING) == 0) { 941 continue; 942 } 943 } 944 945 m = vm_page_lookup(tobject, tpindex); 946 947 if (m == NULL) { 948 /* 949 * There may be swap even if there is no backing page 950 */ 951 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 952 swap_pager_freespace(tobject, tpindex, 1); 953 954 /* 955 * next object 956 */ 957 tobject = tobject->backing_object; 958 if (tobject == NULL) 959 continue; 960 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 961 goto shadowlookup; 962 } 963 964 /* 965 * If the page is busy or not in a normal active state, 966 * we skip it. If the page is not managed there are no 967 * page queues to mess with. Things can break if we mess 968 * with pages in any of the below states. 969 */ 970 if ( 971 m->hold_count || 972 m->wire_count || 973 (m->flags & PG_UNMANAGED) || 974 m->valid != VM_PAGE_BITS_ALL 975 ) { 976 continue; 977 } 978 979 if (vm_page_sleep_busy(m, TRUE, "madvpo")) 980 goto relookup; 981 982 if (advise == MADV_WILLNEED) { 983 vm_page_activate(m); 984 } else if (advise == MADV_DONTNEED) { 985 vm_page_dontneed(m); 986 } else if (advise == MADV_FREE) { 987 /* 988 * Mark the page clean. This will allow the page 989 * to be freed up by the system. However, such pages 990 * are often reused quickly by malloc()/free() 991 * so we do not do anything that would cause 992 * a page fault if we can help it. 993 * 994 * Specifically, we do not try to actually free 995 * the page now nor do we try to put it in the 996 * cache (which would cause a page fault on reuse). 997 * 998 * But we do make the page is freeable as we 999 * can without actually taking the step of unmapping 1000 * it. 1001 */ 1002 pmap_clear_modify(m); 1003 m->dirty = 0; 1004 m->act_count = 0; 1005 vm_page_dontneed(m); 1006 if (tobject->type == OBJT_SWAP) 1007 swap_pager_freespace(tobject, tpindex, 1); 1008 } 1009 } 1010 } 1011 1012 /* 1013 * vm_object_shadow: 1014 * 1015 * Create a new object which is backed by the 1016 * specified existing object range. The source 1017 * object reference is deallocated. 1018 * 1019 * The new object and offset into that object 1020 * are returned in the source parameters. 1021 */ 1022 1023 void 1024 vm_object_shadow(vm_object_t *object, /* IN/OUT */ 1025 vm_ooffset_t *offset, /* IN/OUT */ 1026 vm_size_t length) 1027 { 1028 vm_object_t source; 1029 vm_object_t result; 1030 1031 source = *object; 1032 1033 /* 1034 * Don't create the new object if the old object isn't shared. 1035 */ 1036 1037 if (source != NULL && 1038 source->ref_count == 1 && 1039 source->handle == NULL && 1040 (source->type == OBJT_DEFAULT || 1041 source->type == OBJT_SWAP)) 1042 return; 1043 1044 /* 1045 * Allocate a new object with the given length 1046 */ 1047 1048 if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL) 1049 panic("vm_object_shadow: no object for shadowing"); 1050 1051 /* 1052 * The new object shadows the source object, adding a reference to it. 1053 * Our caller changes his reference to point to the new object, 1054 * removing a reference to the source object. Net result: no change 1055 * of reference count. 1056 * 1057 * Try to optimize the result object's page color when shadowing 1058 * in order to maintain page coloring consistency in the combined 1059 * shadowed object. 1060 */ 1061 result->backing_object = source; 1062 if (source) { 1063 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1064 source->shadow_count++; 1065 source->generation++; 1066 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK; 1067 } 1068 1069 /* 1070 * Store the offset into the source object, and fix up the offset into 1071 * the new object. 1072 */ 1073 1074 result->backing_object_offset = *offset; 1075 1076 /* 1077 * Return the new things 1078 */ 1079 1080 *offset = 0; 1081 *object = result; 1082 } 1083 1084 #define OBSC_TEST_ALL_SHADOWED 0x0001 1085 #define OBSC_COLLAPSE_NOWAIT 0x0002 1086 #define OBSC_COLLAPSE_WAIT 0x0004 1087 1088 static __inline int 1089 vm_object_backing_scan(vm_object_t object, int op) 1090 { 1091 int s; 1092 int r = 1; 1093 vm_page_t p; 1094 vm_object_t backing_object; 1095 vm_pindex_t backing_offset_index; 1096 1097 s = splvm(); 1098 1099 backing_object = object->backing_object; 1100 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1101 1102 /* 1103 * Initial conditions 1104 */ 1105 1106 if (op & OBSC_TEST_ALL_SHADOWED) { 1107 /* 1108 * We do not want to have to test for the existence of 1109 * swap pages in the backing object. XXX but with the 1110 * new swapper this would be pretty easy to do. 1111 * 1112 * XXX what about anonymous MAP_SHARED memory that hasn't 1113 * been ZFOD faulted yet? If we do not test for this, the 1114 * shadow test may succeed! XXX 1115 */ 1116 if (backing_object->type != OBJT_DEFAULT) { 1117 splx(s); 1118 return(0); 1119 } 1120 } 1121 if (op & OBSC_COLLAPSE_WAIT) { 1122 vm_object_set_flag(backing_object, OBJ_DEAD); 1123 } 1124 1125 /* 1126 * Our scan 1127 */ 1128 1129 p = TAILQ_FIRST(&backing_object->memq); 1130 while (p) { 1131 vm_page_t next = TAILQ_NEXT(p, listq); 1132 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1133 1134 if (op & OBSC_TEST_ALL_SHADOWED) { 1135 vm_page_t pp; 1136 1137 /* 1138 * Ignore pages outside the parent object's range 1139 * and outside the parent object's mapping of the 1140 * backing object. 1141 * 1142 * note that we do not busy the backing object's 1143 * page. 1144 */ 1145 1146 if ( 1147 p->pindex < backing_offset_index || 1148 new_pindex >= object->size 1149 ) { 1150 p = next; 1151 continue; 1152 } 1153 1154 /* 1155 * See if the parent has the page or if the parent's 1156 * object pager has the page. If the parent has the 1157 * page but the page is not valid, the parent's 1158 * object pager must have the page. 1159 * 1160 * If this fails, the parent does not completely shadow 1161 * the object and we might as well give up now. 1162 */ 1163 1164 pp = vm_page_lookup(object, new_pindex); 1165 if ( 1166 (pp == NULL || pp->valid == 0) && 1167 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1168 ) { 1169 r = 0; 1170 break; 1171 } 1172 } 1173 1174 /* 1175 * Check for busy page 1176 */ 1177 1178 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1179 vm_page_t pp; 1180 1181 if (op & OBSC_COLLAPSE_NOWAIT) { 1182 if ( 1183 (p->flags & PG_BUSY) || 1184 !p->valid || 1185 p->hold_count || 1186 p->wire_count || 1187 p->busy 1188 ) { 1189 p = next; 1190 continue; 1191 } 1192 } else if (op & OBSC_COLLAPSE_WAIT) { 1193 if (vm_page_sleep_busy(p, TRUE, "vmocol")) { 1194 /* 1195 * If we slept, anything could have 1196 * happened. Since the object is 1197 * marked dead, the backing offset 1198 * should not have changed so we 1199 * just restart our scan. 1200 */ 1201 p = TAILQ_FIRST(&backing_object->memq); 1202 continue; 1203 } 1204 } 1205 1206 /* 1207 * Busy the page 1208 */ 1209 vm_page_busy(p); 1210 1211 KASSERT( 1212 p->object == backing_object, 1213 ("vm_object_qcollapse(): object mismatch") 1214 ); 1215 1216 /* 1217 * Destroy any associated swap 1218 */ 1219 if (backing_object->type == OBJT_SWAP) { 1220 swap_pager_freespace( 1221 backing_object, 1222 p->pindex, 1223 1 1224 ); 1225 } 1226 1227 if ( 1228 p->pindex < backing_offset_index || 1229 new_pindex >= object->size 1230 ) { 1231 /* 1232 * Page is out of the parent object's range, we 1233 * can simply destroy it. 1234 */ 1235 vm_page_protect(p, VM_PROT_NONE); 1236 vm_page_free(p); 1237 p = next; 1238 continue; 1239 } 1240 1241 pp = vm_page_lookup(object, new_pindex); 1242 if ( 1243 pp != NULL || 1244 vm_pager_has_page(object, new_pindex, NULL, NULL) 1245 ) { 1246 /* 1247 * page already exists in parent OR swap exists 1248 * for this location in the parent. Destroy 1249 * the original page from the backing object. 1250 * 1251 * Leave the parent's page alone 1252 */ 1253 vm_page_protect(p, VM_PROT_NONE); 1254 vm_page_free(p); 1255 p = next; 1256 continue; 1257 } 1258 1259 /* 1260 * Page does not exist in parent, rename the 1261 * page from the backing object to the main object. 1262 * 1263 * If the page was mapped to a process, it can remain 1264 * mapped through the rename. 1265 */ 1266 if ((p->queue - p->pc) == PQ_CACHE) 1267 vm_page_deactivate(p); 1268 1269 vm_page_rename(p, object, new_pindex); 1270 /* page automatically made dirty by rename */ 1271 } 1272 p = next; 1273 } 1274 splx(s); 1275 return(r); 1276 } 1277 1278 1279 /* 1280 * this version of collapse allows the operation to occur earlier and 1281 * when paging_in_progress is true for an object... This is not a complete 1282 * operation, but should plug 99.9% of the rest of the leaks. 1283 */ 1284 static void 1285 vm_object_qcollapse(vm_object_t object) 1286 { 1287 vm_object_t backing_object = object->backing_object; 1288 1289 if (backing_object->ref_count != 1) 1290 return; 1291 1292 backing_object->ref_count += 2; 1293 1294 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1295 1296 backing_object->ref_count -= 2; 1297 } 1298 1299 /* 1300 * vm_object_collapse: 1301 * 1302 * Collapse an object with the object backing it. 1303 * Pages in the backing object are moved into the 1304 * parent, and the backing object is deallocated. 1305 */ 1306 void 1307 vm_object_collapse(vm_object_t object) 1308 { 1309 while (TRUE) { 1310 vm_object_t backing_object; 1311 1312 /* 1313 * Verify that the conditions are right for collapse: 1314 * 1315 * The object exists and the backing object exists. 1316 */ 1317 if (object == NULL) 1318 break; 1319 1320 if ((backing_object = object->backing_object) == NULL) 1321 break; 1322 1323 /* 1324 * we check the backing object first, because it is most likely 1325 * not collapsable. 1326 */ 1327 if (backing_object->handle != NULL || 1328 (backing_object->type != OBJT_DEFAULT && 1329 backing_object->type != OBJT_SWAP) || 1330 (backing_object->flags & OBJ_DEAD) || 1331 object->handle != NULL || 1332 (object->type != OBJT_DEFAULT && 1333 object->type != OBJT_SWAP) || 1334 (object->flags & OBJ_DEAD)) { 1335 break; 1336 } 1337 1338 if ( 1339 object->paging_in_progress != 0 || 1340 backing_object->paging_in_progress != 0 1341 ) { 1342 vm_object_qcollapse(object); 1343 break; 1344 } 1345 1346 /* 1347 * We know that we can either collapse the backing object (if 1348 * the parent is the only reference to it) or (perhaps) have 1349 * the parent bypass the object if the parent happens to shadow 1350 * all the resident pages in the entire backing object. 1351 * 1352 * This is ignoring pager-backed pages such as swap pages. 1353 * vm_object_backing_scan fails the shadowing test in this 1354 * case. 1355 */ 1356 1357 if (backing_object->ref_count == 1) { 1358 /* 1359 * If there is exactly one reference to the backing 1360 * object, we can collapse it into the parent. 1361 */ 1362 1363 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1364 1365 /* 1366 * Move the pager from backing_object to object. 1367 */ 1368 1369 if (backing_object->type == OBJT_SWAP) { 1370 vm_object_pip_add(backing_object, 1); 1371 1372 /* 1373 * scrap the paging_offset junk and do a 1374 * discrete copy. This also removes major 1375 * assumptions about how the swap-pager 1376 * works from where it doesn't belong. The 1377 * new swapper is able to optimize the 1378 * destroy-source case. 1379 */ 1380 1381 vm_object_pip_add(object, 1); 1382 swap_pager_copy( 1383 backing_object, 1384 object, 1385 OFF_TO_IDX(object->backing_object_offset), TRUE); 1386 vm_object_pip_wakeup(object); 1387 1388 vm_object_pip_wakeup(backing_object); 1389 } 1390 /* 1391 * Object now shadows whatever backing_object did. 1392 * Note that the reference to 1393 * backing_object->backing_object moves from within 1394 * backing_object to within object. 1395 */ 1396 1397 LIST_REMOVE(object, shadow_list); 1398 object->backing_object->shadow_count--; 1399 object->backing_object->generation++; 1400 if (backing_object->backing_object) { 1401 LIST_REMOVE(backing_object, shadow_list); 1402 backing_object->backing_object->shadow_count--; 1403 backing_object->backing_object->generation++; 1404 } 1405 object->backing_object = backing_object->backing_object; 1406 if (object->backing_object) { 1407 LIST_INSERT_HEAD( 1408 &object->backing_object->shadow_head, 1409 object, 1410 shadow_list 1411 ); 1412 object->backing_object->shadow_count++; 1413 object->backing_object->generation++; 1414 } 1415 1416 object->backing_object_offset += 1417 backing_object->backing_object_offset; 1418 1419 /* 1420 * Discard backing_object. 1421 * 1422 * Since the backing object has no pages, no pager left, 1423 * and no object references within it, all that is 1424 * necessary is to dispose of it. 1425 */ 1426 1427 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1428 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object)); 1429 TAILQ_REMOVE( 1430 &vm_object_list, 1431 backing_object, 1432 object_list 1433 ); 1434 vm_object_count--; 1435 1436 zfree(obj_zone, backing_object); 1437 1438 object_collapses++; 1439 } else { 1440 vm_object_t new_backing_object; 1441 1442 /* 1443 * If we do not entirely shadow the backing object, 1444 * there is nothing we can do so we give up. 1445 */ 1446 1447 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1448 break; 1449 } 1450 1451 /* 1452 * Make the parent shadow the next object in the 1453 * chain. Deallocating backing_object will not remove 1454 * it, since its reference count is at least 2. 1455 */ 1456 1457 LIST_REMOVE(object, shadow_list); 1458 backing_object->shadow_count--; 1459 backing_object->generation++; 1460 1461 new_backing_object = backing_object->backing_object; 1462 if ((object->backing_object = new_backing_object) != NULL) { 1463 vm_object_reference(new_backing_object); 1464 LIST_INSERT_HEAD( 1465 &new_backing_object->shadow_head, 1466 object, 1467 shadow_list 1468 ); 1469 new_backing_object->shadow_count++; 1470 new_backing_object->generation++; 1471 object->backing_object_offset += 1472 backing_object->backing_object_offset; 1473 } 1474 1475 /* 1476 * Drop the reference count on backing_object. Since 1477 * its ref_count was at least 2, it will not vanish; 1478 * so we don't need to call vm_object_deallocate, but 1479 * we do anyway. 1480 */ 1481 vm_object_deallocate(backing_object); 1482 object_bypasses++; 1483 } 1484 1485 /* 1486 * Try again with this object's new backing object. 1487 */ 1488 } 1489 } 1490 1491 /* 1492 * vm_object_page_remove: [internal] 1493 * 1494 * Removes all physical pages in the specified 1495 * object range from the object's list of pages. 1496 * 1497 * The object must be locked. 1498 */ 1499 void 1500 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1501 boolean_t clean_only) 1502 { 1503 vm_page_t p, next; 1504 unsigned int size; 1505 int all; 1506 1507 if (object == NULL || 1508 object->resident_page_count == 0) 1509 return; 1510 1511 all = ((end == 0) && (start == 0)); 1512 1513 /* 1514 * Since physically-backed objects do not use managed pages, we can't 1515 * remove pages from the object (we must instead remove the page 1516 * references, and then destroy the object). 1517 */ 1518 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object")); 1519 1520 vm_object_pip_add(object, 1); 1521 again: 1522 size = end - start; 1523 if (all || size > object->resident_page_count / 4) { 1524 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 1525 next = TAILQ_NEXT(p, listq); 1526 if (all || ((start <= p->pindex) && (p->pindex < end))) { 1527 if (p->wire_count != 0) { 1528 vm_page_protect(p, VM_PROT_NONE); 1529 if (!clean_only) 1530 p->valid = 0; 1531 continue; 1532 } 1533 1534 /* 1535 * The busy flags are only cleared at 1536 * interrupt -- minimize the spl transitions 1537 */ 1538 1539 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1540 goto again; 1541 1542 if (clean_only && p->valid) { 1543 vm_page_test_dirty(p); 1544 if (p->valid & p->dirty) 1545 continue; 1546 } 1547 1548 vm_page_busy(p); 1549 vm_page_protect(p, VM_PROT_NONE); 1550 vm_page_free(p); 1551 } 1552 } 1553 } else { 1554 while (size > 0) { 1555 if ((p = vm_page_lookup(object, start)) != 0) { 1556 1557 if (p->wire_count != 0) { 1558 vm_page_protect(p, VM_PROT_NONE); 1559 if (!clean_only) 1560 p->valid = 0; 1561 start += 1; 1562 size -= 1; 1563 continue; 1564 } 1565 1566 /* 1567 * The busy flags are only cleared at 1568 * interrupt -- minimize the spl transitions 1569 */ 1570 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1571 goto again; 1572 1573 if (clean_only && p->valid) { 1574 vm_page_test_dirty(p); 1575 if (p->valid & p->dirty) { 1576 start += 1; 1577 size -= 1; 1578 continue; 1579 } 1580 } 1581 1582 vm_page_busy(p); 1583 vm_page_protect(p, VM_PROT_NONE); 1584 vm_page_free(p); 1585 } 1586 start += 1; 1587 size -= 1; 1588 } 1589 } 1590 vm_object_pip_wakeup(object); 1591 } 1592 1593 /* 1594 * Routine: vm_object_coalesce 1595 * Function: Coalesces two objects backing up adjoining 1596 * regions of memory into a single object. 1597 * 1598 * returns TRUE if objects were combined. 1599 * 1600 * NOTE: Only works at the moment if the second object is NULL - 1601 * if it's not, which object do we lock first? 1602 * 1603 * Parameters: 1604 * prev_object First object to coalesce 1605 * prev_offset Offset into prev_object 1606 * next_object Second object into coalesce 1607 * next_offset Offset into next_object 1608 * 1609 * prev_size Size of reference to prev_object 1610 * next_size Size of reference to next_object 1611 * 1612 * Conditions: 1613 * The object must *not* be locked. 1614 */ 1615 boolean_t 1616 vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, 1617 vm_size_t prev_size, vm_size_t next_size) 1618 { 1619 vm_pindex_t next_pindex; 1620 1621 if (prev_object == NULL) { 1622 return (TRUE); 1623 } 1624 1625 if (prev_object->type != OBJT_DEFAULT && 1626 prev_object->type != OBJT_SWAP) { 1627 return (FALSE); 1628 } 1629 1630 /* 1631 * Try to collapse the object first 1632 */ 1633 vm_object_collapse(prev_object); 1634 1635 /* 1636 * Can't coalesce if: . more than one reference . paged out . shadows 1637 * another object . has a copy elsewhere (any of which mean that the 1638 * pages not mapped to prev_entry may be in use anyway) 1639 */ 1640 1641 if (prev_object->backing_object != NULL) { 1642 return (FALSE); 1643 } 1644 1645 prev_size >>= PAGE_SHIFT; 1646 next_size >>= PAGE_SHIFT; 1647 next_pindex = prev_pindex + prev_size; 1648 1649 if ((prev_object->ref_count > 1) && 1650 (prev_object->size != next_pindex)) { 1651 return (FALSE); 1652 } 1653 1654 /* 1655 * Remove any pages that may still be in the object from a previous 1656 * deallocation. 1657 */ 1658 if (next_pindex < prev_object->size) { 1659 vm_object_page_remove(prev_object, 1660 next_pindex, 1661 next_pindex + next_size, FALSE); 1662 if (prev_object->type == OBJT_SWAP) 1663 swap_pager_freespace(prev_object, 1664 next_pindex, next_size); 1665 } 1666 1667 /* 1668 * Extend the object if necessary. 1669 */ 1670 if (next_pindex + next_size > prev_object->size) 1671 prev_object->size = next_pindex + next_size; 1672 1673 return (TRUE); 1674 } 1675 1676 void 1677 vm_object_set_writeable_dirty(vm_object_t object) 1678 { 1679 struct vnode *vp; 1680 lwkt_tokref vlock; 1681 1682 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1683 if (object->type == OBJT_VNODE && 1684 (vp = (struct vnode *)object->handle) != NULL) { 1685 if ((vp->v_flag & VOBJDIRTY) == 0) { 1686 lwkt_gettoken(&vlock, vp->v_interlock); 1687 vp->v_flag |= VOBJDIRTY; 1688 lwkt_reltoken(&vlock); 1689 } 1690 } 1691 } 1692 1693 1694 1695 #include "opt_ddb.h" 1696 #ifdef DDB 1697 #include <sys/kernel.h> 1698 1699 #include <sys/cons.h> 1700 1701 #include <ddb/ddb.h> 1702 1703 static int _vm_object_in_map (vm_map_t map, vm_object_t object, 1704 vm_map_entry_t entry); 1705 static int vm_object_in_map (vm_object_t object); 1706 1707 static int 1708 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1709 { 1710 vm_map_t tmpm; 1711 vm_map_entry_t tmpe; 1712 vm_object_t obj; 1713 int entcount; 1714 1715 if (map == 0) 1716 return 0; 1717 1718 if (entry == 0) { 1719 tmpe = map->header.next; 1720 entcount = map->nentries; 1721 while (entcount-- && (tmpe != &map->header)) { 1722 if( _vm_object_in_map(map, object, tmpe)) { 1723 return 1; 1724 } 1725 tmpe = tmpe->next; 1726 } 1727 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1728 tmpm = entry->object.sub_map; 1729 tmpe = tmpm->header.next; 1730 entcount = tmpm->nentries; 1731 while (entcount-- && tmpe != &tmpm->header) { 1732 if( _vm_object_in_map(tmpm, object, tmpe)) { 1733 return 1; 1734 } 1735 tmpe = tmpe->next; 1736 } 1737 } else if ((obj = entry->object.vm_object) != NULL) { 1738 for(; obj; obj=obj->backing_object) 1739 if( obj == object) { 1740 return 1; 1741 } 1742 } 1743 return 0; 1744 } 1745 1746 static int 1747 vm_object_in_map(vm_object_t object) 1748 { 1749 struct proc *p; 1750 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 1751 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1752 continue; 1753 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) 1754 return 1; 1755 } 1756 if( _vm_object_in_map( kernel_map, object, 0)) 1757 return 1; 1758 if( _vm_object_in_map( pager_map, object, 0)) 1759 return 1; 1760 if( _vm_object_in_map( buffer_map, object, 0)) 1761 return 1; 1762 if( _vm_object_in_map( mb_map, object, 0)) 1763 return 1; 1764 return 0; 1765 } 1766 1767 DB_SHOW_COMMAND(vmochk, vm_object_check) 1768 { 1769 vm_object_t object; 1770 1771 /* 1772 * make sure that internal objs are in a map somewhere 1773 * and none have zero ref counts. 1774 */ 1775 for (object = TAILQ_FIRST(&vm_object_list); 1776 object != NULL; 1777 object = TAILQ_NEXT(object, object_list)) { 1778 if (object->handle == NULL && 1779 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1780 if (object->ref_count == 0) { 1781 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1782 (long)object->size); 1783 } 1784 if (!vm_object_in_map(object)) { 1785 db_printf( 1786 "vmochk: internal obj is not in a map: " 1787 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1788 object->ref_count, (u_long)object->size, 1789 (u_long)object->size, 1790 (void *)object->backing_object); 1791 } 1792 } 1793 } 1794 } 1795 1796 /* 1797 * vm_object_print: [ debug ] 1798 */ 1799 DB_SHOW_COMMAND(object, vm_object_print_static) 1800 { 1801 /* XXX convert args. */ 1802 vm_object_t object = (vm_object_t)addr; 1803 boolean_t full = have_addr; 1804 1805 vm_page_t p; 1806 1807 /* XXX count is an (unused) arg. Avoid shadowing it. */ 1808 #define count was_count 1809 1810 int count; 1811 1812 if (object == NULL) 1813 return; 1814 1815 db_iprintf( 1816 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n", 1817 object, (int)object->type, (u_long)object->size, 1818 object->resident_page_count, object->ref_count, object->flags); 1819 /* 1820 * XXX no %qd in kernel. Truncate object->backing_object_offset. 1821 */ 1822 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n", 1823 object->shadow_count, 1824 object->backing_object ? object->backing_object->ref_count : 0, 1825 object->backing_object, (long)object->backing_object_offset); 1826 1827 if (!full) 1828 return; 1829 1830 db_indent += 2; 1831 count = 0; 1832 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = TAILQ_NEXT(p, listq)) { 1833 if (count == 0) 1834 db_iprintf("memory:="); 1835 else if (count == 6) { 1836 db_printf("\n"); 1837 db_iprintf(" ..."); 1838 count = 0; 1839 } else 1840 db_printf(","); 1841 count++; 1842 1843 db_printf("(off=0x%lx,page=0x%lx)", 1844 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p)); 1845 } 1846 if (count != 0) 1847 db_printf("\n"); 1848 db_indent -= 2; 1849 } 1850 1851 /* XXX. */ 1852 #undef count 1853 1854 /* XXX need this non-static entry for calling from vm_map_print. */ 1855 void 1856 vm_object_print(/* db_expr_t */ long addr, 1857 boolean_t have_addr, 1858 /* db_expr_t */ long count, 1859 char *modif) 1860 { 1861 vm_object_print_static(addr, have_addr, count, modif); 1862 } 1863 1864 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 1865 { 1866 vm_object_t object; 1867 int nl = 0; 1868 int c; 1869 for (object = TAILQ_FIRST(&vm_object_list); 1870 object != NULL; 1871 object = TAILQ_NEXT(object, object_list)) { 1872 vm_pindex_t idx, fidx; 1873 vm_pindex_t osize; 1874 vm_paddr_t pa = -1, padiff; 1875 int rcount; 1876 vm_page_t m; 1877 1878 db_printf("new object: %p\n", (void *)object); 1879 if ( nl > 18) { 1880 c = cngetc(); 1881 if (c != ' ') 1882 return; 1883 nl = 0; 1884 } 1885 nl++; 1886 rcount = 0; 1887 fidx = 0; 1888 osize = object->size; 1889 if (osize > 128) 1890 osize = 128; 1891 for(idx=0;idx<osize;idx++) { 1892 m = vm_page_lookup(object, idx); 1893 if (m == NULL) { 1894 if (rcount) { 1895 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1896 (long)fidx, rcount, (long)pa); 1897 if ( nl > 18) { 1898 c = cngetc(); 1899 if (c != ' ') 1900 return; 1901 nl = 0; 1902 } 1903 nl++; 1904 rcount = 0; 1905 } 1906 continue; 1907 } 1908 1909 1910 if (rcount && 1911 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 1912 ++rcount; 1913 continue; 1914 } 1915 if (rcount) { 1916 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 1917 padiff >>= PAGE_SHIFT; 1918 padiff &= PQ_L2_MASK; 1919 if (padiff == 0) { 1920 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 1921 ++rcount; 1922 continue; 1923 } 1924 db_printf(" index(%ld)run(%d)pa(0x%lx)", 1925 (long)fidx, rcount, (long)pa); 1926 db_printf("pd(%ld)\n", (long)padiff); 1927 if ( nl > 18) { 1928 c = cngetc(); 1929 if (c != ' ') 1930 return; 1931 nl = 0; 1932 } 1933 nl++; 1934 } 1935 fidx = idx; 1936 pa = VM_PAGE_TO_PHYS(m); 1937 rcount = 1; 1938 } 1939 if (rcount) { 1940 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1941 (long)fidx, rcount, (long)pa); 1942 if ( nl > 18) { 1943 c = cngetc(); 1944 if (c != ' ') 1945 return; 1946 nl = 0; 1947 } 1948 nl++; 1949 } 1950 } 1951 } 1952 #endif /* DDB */ 1953