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 1.6 2003/07/06 21:23:56 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_inittoken(&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 zinitna(obj_zone, NULL, NULL, 0, 0, 0, 1); 222 } 223 224 /* 225 * vm_object_allocate: 226 * 227 * Returns a new object with the given size. 228 */ 229 230 vm_object_t 231 vm_object_allocate(type, size) 232 objtype_t type; 233 vm_size_t size; 234 { 235 vm_object_t result; 236 237 result = (vm_object_t) zalloc(obj_zone); 238 239 _vm_object_allocate(type, size, result); 240 241 return (result); 242 } 243 244 245 /* 246 * vm_object_reference: 247 * 248 * Gets another reference to the given object. 249 */ 250 void 251 vm_object_reference(object) 252 vm_object_t object; 253 { 254 if (object == NULL) 255 return; 256 257 #if 0 258 /* object can be re-referenced during final cleaning */ 259 KASSERT(!(object->flags & OBJ_DEAD), 260 ("vm_object_reference: attempting to reference dead obj")); 261 #endif 262 263 object->ref_count++; 264 if (object->type == OBJT_VNODE) { 265 while (vget((struct vnode *) object->handle, LK_RETRY|LK_NOOBJ, curthread)) { 266 printf("vm_object_reference: delay in getting object\n"); 267 } 268 } 269 } 270 271 void 272 vm_object_vndeallocate(object) 273 vm_object_t object; 274 { 275 struct vnode *vp = (struct vnode *) object->handle; 276 277 KASSERT(object->type == OBJT_VNODE, 278 ("vm_object_vndeallocate: not a vnode object")); 279 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 280 #ifdef INVARIANTS 281 if (object->ref_count == 0) { 282 vprint("vm_object_vndeallocate", vp); 283 panic("vm_object_vndeallocate: bad object reference count"); 284 } 285 #endif 286 287 object->ref_count--; 288 if (object->ref_count == 0) { 289 vp->v_flag &= ~VTEXT; 290 vm_object_clear_flag(object, OBJ_OPT); 291 } 292 vrele(vp); 293 } 294 295 /* 296 * vm_object_deallocate: 297 * 298 * Release a reference to the specified object, 299 * gained either through a vm_object_allocate 300 * or a vm_object_reference call. When all references 301 * are gone, storage associated with this object 302 * may be relinquished. 303 * 304 * No object may be locked. 305 */ 306 void 307 vm_object_deallocate(object) 308 vm_object_t object; 309 { 310 vm_object_t temp; 311 312 while (object != NULL) { 313 314 if (object->type == OBJT_VNODE) { 315 vm_object_vndeallocate(object); 316 return; 317 } 318 319 if (object->ref_count == 0) { 320 panic("vm_object_deallocate: object deallocated too many times: %d", object->type); 321 } else if (object->ref_count > 2) { 322 object->ref_count--; 323 return; 324 } 325 326 /* 327 * Here on ref_count of one or two, which are special cases for 328 * objects. 329 */ 330 if ((object->ref_count == 2) && (object->shadow_count == 0)) { 331 vm_object_set_flag(object, OBJ_ONEMAPPING); 332 object->ref_count--; 333 return; 334 } else if ((object->ref_count == 2) && (object->shadow_count == 1)) { 335 object->ref_count--; 336 if ((object->handle == NULL) && 337 (object->type == OBJT_DEFAULT || 338 object->type == OBJT_SWAP)) { 339 vm_object_t robject; 340 341 robject = LIST_FIRST(&object->shadow_head); 342 KASSERT(robject != NULL, 343 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 344 object->ref_count, 345 object->shadow_count)); 346 if ((robject->handle == NULL) && 347 (robject->type == OBJT_DEFAULT || 348 robject->type == OBJT_SWAP)) { 349 350 robject->ref_count++; 351 352 while ( 353 robject->paging_in_progress || 354 object->paging_in_progress 355 ) { 356 vm_object_pip_sleep(robject, "objde1"); 357 vm_object_pip_sleep(object, "objde2"); 358 } 359 360 if (robject->ref_count == 1) { 361 robject->ref_count--; 362 object = robject; 363 goto doterm; 364 } 365 366 object = robject; 367 vm_object_collapse(object); 368 continue; 369 } 370 } 371 372 return; 373 374 } else { 375 object->ref_count--; 376 if (object->ref_count != 0) 377 return; 378 } 379 380 doterm: 381 382 temp = object->backing_object; 383 if (temp) { 384 LIST_REMOVE(object, shadow_list); 385 temp->shadow_count--; 386 if (temp->ref_count == 0) 387 vm_object_clear_flag(temp, OBJ_OPT); 388 temp->generation++; 389 object->backing_object = NULL; 390 } 391 392 /* 393 * Don't double-terminate, we could be in a termination 394 * recursion due to the terminate having to sync data 395 * to disk. 396 */ 397 if ((object->flags & OBJ_DEAD) == 0) 398 vm_object_terminate(object); 399 object = temp; 400 } 401 } 402 403 /* 404 * vm_object_terminate actually destroys the specified object, freeing 405 * up all previously used resources. 406 * 407 * The object must be locked. 408 * This routine may block. 409 */ 410 void 411 vm_object_terminate(object) 412 vm_object_t object; 413 { 414 vm_page_t p; 415 int s; 416 417 /* 418 * Make sure no one uses us. 419 */ 420 vm_object_set_flag(object, OBJ_DEAD); 421 422 /* 423 * wait for the pageout daemon to be done with the object 424 */ 425 vm_object_pip_wait(object, "objtrm"); 426 427 KASSERT(!object->paging_in_progress, 428 ("vm_object_terminate: pageout in progress")); 429 430 /* 431 * Clean and free the pages, as appropriate. All references to the 432 * object are gone, so we don't need to lock it. 433 */ 434 if (object->type == OBJT_VNODE) { 435 struct vnode *vp; 436 437 /* 438 * Freeze optimized copies. 439 */ 440 vm_freeze_copyopts(object, 0, object->size); 441 442 /* 443 * Clean pages and flush buffers. 444 */ 445 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 446 447 vp = (struct vnode *) object->handle; 448 vinvalbuf(vp, V_SAVE, NULL, 0, 0); 449 } 450 451 /* 452 * Wait for any I/O to complete, after which there had better not 453 * be any references left on the object. 454 */ 455 vm_object_pip_wait(object, "objtrm"); 456 457 if (object->ref_count != 0) 458 panic("vm_object_terminate: object with references, ref_count=%d", object->ref_count); 459 460 /* 461 * Now free any remaining pages. For internal objects, this also 462 * removes them from paging queues. Don't free wired pages, just 463 * remove them from the object. 464 */ 465 s = splvm(); 466 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 467 if (p->busy || (p->flags & PG_BUSY)) 468 panic("vm_object_terminate: freeing busy page %p\n", p); 469 if (p->wire_count == 0) { 470 vm_page_busy(p); 471 vm_page_free(p); 472 mycpu->gd_cnt.v_pfree++; 473 } else { 474 vm_page_busy(p); 475 vm_page_remove(p); 476 } 477 } 478 splx(s); 479 480 /* 481 * Let the pager know object is dead. 482 */ 483 vm_pager_deallocate(object); 484 485 /* 486 * Remove the object from the global object list. 487 */ 488 lwkt_gettoken(&vm_object_list_token); 489 TAILQ_REMOVE(&vm_object_list, object, object_list); 490 lwkt_reltoken(&vm_object_list_token); 491 492 wakeup(object); 493 494 /* 495 * Free the space for the object. 496 */ 497 zfree(obj_zone, object); 498 } 499 500 /* 501 * vm_object_page_clean 502 * 503 * Clean all dirty pages in the specified range of object. Leaves page 504 * on whatever queue it is currently on. If NOSYNC is set then do not 505 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 506 * leaving the object dirty. 507 * 508 * When stuffing pages asynchronously, allow clustering. XXX we need a 509 * synchronous clustering mode implementation. 510 * 511 * Odd semantics: if start == end, we clean everything. 512 * 513 * The object must be locked. 514 */ 515 516 void 517 vm_object_page_clean(object, start, end, flags) 518 vm_object_t object; 519 vm_pindex_t start; 520 vm_pindex_t end; 521 int flags; 522 { 523 vm_page_t p, np; 524 vm_offset_t tstart, tend; 525 vm_pindex_t pi; 526 struct vnode *vp; 527 int clearobjflags; 528 int pagerflags; 529 int curgeneration; 530 531 if (object->type != OBJT_VNODE || 532 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 533 return; 534 535 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 536 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 537 538 vp = object->handle; 539 540 vm_object_set_flag(object, OBJ_CLEANING); 541 542 /* 543 * Handle 'entire object' case 544 */ 545 tstart = start; 546 if (end == 0) { 547 tend = object->size; 548 } else { 549 tend = end; 550 } 551 552 /* 553 * If the caller is smart and only msync()s a range he knows is 554 * dirty, we may be able to avoid an object scan. This results in 555 * a phenominal improvement in performance. We cannot do this 556 * as a matter of course because the object may be huge - e.g. 557 * the size might be in the gigabytes or terrabytes. 558 */ 559 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 560 vm_offset_t tscan; 561 int scanlimit; 562 int scanreset; 563 564 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 565 if (scanreset < 16) 566 scanreset = 16; 567 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 568 569 scanlimit = scanreset; 570 tscan = tstart; 571 while (tscan < tend) { 572 curgeneration = object->generation; 573 p = vm_page_lookup(object, tscan); 574 if (p == NULL || p->valid == 0 || 575 (p->queue - p->pc) == PQ_CACHE) { 576 if (--scanlimit == 0) 577 break; 578 ++tscan; 579 continue; 580 } 581 vm_page_test_dirty(p); 582 if ((p->dirty & p->valid) == 0) { 583 if (--scanlimit == 0) 584 break; 585 ++tscan; 586 continue; 587 } 588 /* 589 * If we have been asked to skip nosync pages and 590 * this is a nosync page, we can't continue. 591 */ 592 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 593 if (--scanlimit == 0) 594 break; 595 ++tscan; 596 continue; 597 } 598 scanlimit = scanreset; 599 600 /* 601 * This returns 0 if it was unable to busy the first 602 * page (i.e. had to sleep). 603 */ 604 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 605 } 606 607 /* 608 * If everything was dirty and we flushed it successfully, 609 * and the requested range is not the entire object, we 610 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 611 * return immediately. 612 */ 613 if (tscan >= tend && (tstart || tend < object->size)) { 614 vm_object_clear_flag(object, OBJ_CLEANING); 615 return; 616 } 617 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 618 } 619 620 /* 621 * Generally set CLEANCHK interlock and make the page read-only so 622 * we can then clear the object flags. 623 * 624 * However, if this is a nosync mmap then the object is likely to 625 * stay dirty so do not mess with the page and do not clear the 626 * object flags. 627 */ 628 629 clearobjflags = 1; 630 631 for(p = TAILQ_FIRST(&object->memq); p; p = TAILQ_NEXT(p, listq)) { 632 vm_page_flag_set(p, PG_CLEANCHK); 633 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 634 clearobjflags = 0; 635 else 636 vm_page_protect(p, VM_PROT_READ); 637 } 638 639 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 640 struct vnode *vp; 641 642 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 643 if (object->type == OBJT_VNODE && 644 (vp = (struct vnode *)object->handle) != NULL) { 645 if (vp->v_flag & VOBJDIRTY) { 646 lwkt_gettoken(&vp->v_interlock); 647 vp->v_flag &= ~VOBJDIRTY; 648 lwkt_reltoken(&vp->v_interlock); 649 } 650 } 651 } 652 653 rescan: 654 curgeneration = object->generation; 655 656 for(p = TAILQ_FIRST(&object->memq); p; p = np) { 657 int n; 658 659 np = TAILQ_NEXT(p, listq); 660 661 again: 662 pi = p->pindex; 663 if (((p->flags & PG_CLEANCHK) == 0) || 664 (pi < tstart) || (pi >= tend) || 665 (p->valid == 0) || 666 ((p->queue - p->pc) == PQ_CACHE)) { 667 vm_page_flag_clear(p, PG_CLEANCHK); 668 continue; 669 } 670 671 vm_page_test_dirty(p); 672 if ((p->dirty & p->valid) == 0) { 673 vm_page_flag_clear(p, PG_CLEANCHK); 674 continue; 675 } 676 677 /* 678 * If we have been asked to skip nosync pages and this is a 679 * nosync page, skip it. Note that the object flags were 680 * not cleared in this case so we do not have to set them. 681 */ 682 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 683 vm_page_flag_clear(p, PG_CLEANCHK); 684 continue; 685 } 686 687 n = vm_object_page_collect_flush(object, p, 688 curgeneration, pagerflags); 689 if (n == 0) 690 goto rescan; 691 if (object->generation != curgeneration) 692 goto rescan; 693 694 /* 695 * Try to optimize the next page. If we can't we pick up 696 * our (random) scan where we left off. 697 */ 698 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 699 if ((p = vm_page_lookup(object, pi + n)) != NULL) 700 goto again; 701 } 702 } 703 704 #if 0 705 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 706 #endif 707 708 vm_object_clear_flag(object, OBJ_CLEANING); 709 return; 710 } 711 712 static int 713 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 714 { 715 int runlen; 716 int s; 717 int maxf; 718 int chkb; 719 int maxb; 720 int i; 721 vm_pindex_t pi; 722 vm_page_t maf[vm_pageout_page_count]; 723 vm_page_t mab[vm_pageout_page_count]; 724 vm_page_t ma[vm_pageout_page_count]; 725 726 s = splvm(); 727 pi = p->pindex; 728 while (vm_page_sleep_busy(p, TRUE, "vpcwai")) { 729 if (object->generation != curgeneration) { 730 splx(s); 731 return(0); 732 } 733 } 734 735 maxf = 0; 736 for(i = 1; i < vm_pageout_page_count; i++) { 737 vm_page_t tp; 738 739 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 740 if ((tp->flags & PG_BUSY) || 741 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 742 (tp->flags & PG_CLEANCHK) == 0) || 743 (tp->busy != 0)) 744 break; 745 if((tp->queue - tp->pc) == PQ_CACHE) { 746 vm_page_flag_clear(tp, PG_CLEANCHK); 747 break; 748 } 749 vm_page_test_dirty(tp); 750 if ((tp->dirty & tp->valid) == 0) { 751 vm_page_flag_clear(tp, PG_CLEANCHK); 752 break; 753 } 754 maf[ i - 1 ] = tp; 755 maxf++; 756 continue; 757 } 758 break; 759 } 760 761 maxb = 0; 762 chkb = vm_pageout_page_count - maxf; 763 if (chkb) { 764 for(i = 1; i < chkb;i++) { 765 vm_page_t tp; 766 767 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 768 if ((tp->flags & PG_BUSY) || 769 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 770 (tp->flags & PG_CLEANCHK) == 0) || 771 (tp->busy != 0)) 772 break; 773 if((tp->queue - tp->pc) == PQ_CACHE) { 774 vm_page_flag_clear(tp, PG_CLEANCHK); 775 break; 776 } 777 vm_page_test_dirty(tp); 778 if ((tp->dirty & tp->valid) == 0) { 779 vm_page_flag_clear(tp, PG_CLEANCHK); 780 break; 781 } 782 mab[ i - 1 ] = tp; 783 maxb++; 784 continue; 785 } 786 break; 787 } 788 } 789 790 for(i = 0; i < maxb; i++) { 791 int index = (maxb - i) - 1; 792 ma[index] = mab[i]; 793 vm_page_flag_clear(ma[index], PG_CLEANCHK); 794 } 795 vm_page_flag_clear(p, PG_CLEANCHK); 796 ma[maxb] = p; 797 for(i = 0; i < maxf; i++) { 798 int index = (maxb + i) + 1; 799 ma[index] = maf[i]; 800 vm_page_flag_clear(ma[index], PG_CLEANCHK); 801 } 802 runlen = maxb + maxf + 1; 803 804 splx(s); 805 vm_pageout_flush(ma, runlen, pagerflags); 806 for (i = 0; i < runlen; i++) { 807 if (ma[i]->valid & ma[i]->dirty) { 808 vm_page_protect(ma[i], VM_PROT_READ); 809 vm_page_flag_set(ma[i], PG_CLEANCHK); 810 811 /* 812 * maxf will end up being the actual number of pages 813 * we wrote out contiguously, non-inclusive of the 814 * first page. We do not count look-behind pages. 815 */ 816 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 817 maxf = i - maxb - 1; 818 } 819 } 820 return(maxf + 1); 821 } 822 823 #ifdef not_used 824 /* XXX I cannot tell if this should be an exported symbol */ 825 /* 826 * vm_object_deactivate_pages 827 * 828 * Deactivate all pages in the specified object. (Keep its pages 829 * in memory even though it is no longer referenced.) 830 * 831 * The object must be locked. 832 */ 833 static void 834 vm_object_deactivate_pages(object) 835 vm_object_t object; 836 { 837 vm_page_t p, next; 838 839 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 840 next = TAILQ_NEXT(p, listq); 841 vm_page_deactivate(p); 842 } 843 } 844 #endif 845 846 /* 847 * Same as vm_object_pmap_copy, except range checking really 848 * works, and is meant for small sections of an object. 849 * 850 * This code protects resident pages by making them read-only 851 * and is typically called on a fork or split when a page 852 * is converted to copy-on-write. 853 * 854 * NOTE: If the page is already at VM_PROT_NONE, calling 855 * vm_page_protect will have no effect. 856 */ 857 858 void 859 vm_object_pmap_copy_1(object, start, end) 860 vm_object_t object; 861 vm_pindex_t start; 862 vm_pindex_t end; 863 { 864 vm_pindex_t idx; 865 vm_page_t p; 866 867 if (object == NULL || (object->flags & OBJ_WRITEABLE) == 0) 868 return; 869 870 for (idx = start; idx < end; idx++) { 871 p = vm_page_lookup(object, idx); 872 if (p == NULL) 873 continue; 874 vm_page_protect(p, VM_PROT_READ); 875 } 876 } 877 878 /* 879 * vm_object_pmap_remove: 880 * 881 * Removes all physical pages in the specified 882 * object range from all physical maps. 883 * 884 * The object must *not* be locked. 885 */ 886 void 887 vm_object_pmap_remove(object, start, end) 888 vm_object_t object; 889 vm_pindex_t start; 890 vm_pindex_t end; 891 { 892 vm_page_t p; 893 894 if (object == NULL) 895 return; 896 for (p = TAILQ_FIRST(&object->memq); 897 p != NULL; 898 p = TAILQ_NEXT(p, listq)) { 899 if (p->pindex >= start && p->pindex < end) 900 vm_page_protect(p, VM_PROT_NONE); 901 } 902 if ((start == 0) && (object->size == end)) 903 vm_object_clear_flag(object, OBJ_WRITEABLE); 904 } 905 906 /* 907 * vm_object_madvise: 908 * 909 * Implements the madvise function at the object/page level. 910 * 911 * MADV_WILLNEED (any object) 912 * 913 * Activate the specified pages if they are resident. 914 * 915 * MADV_DONTNEED (any object) 916 * 917 * Deactivate the specified pages if they are resident. 918 * 919 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 920 * OBJ_ONEMAPPING only) 921 * 922 * Deactivate and clean the specified pages if they are 923 * resident. This permits the process to reuse the pages 924 * without faulting or the kernel to reclaim the pages 925 * without I/O. 926 */ 927 void 928 vm_object_madvise(object, pindex, count, advise) 929 vm_object_t object; 930 vm_pindex_t pindex; 931 int count; 932 int advise; 933 { 934 vm_pindex_t end, tpindex; 935 vm_object_t tobject; 936 vm_page_t m; 937 938 if (object == NULL) 939 return; 940 941 end = pindex + count; 942 943 /* 944 * Locate and adjust resident pages 945 */ 946 947 for (; pindex < end; pindex += 1) { 948 relookup: 949 tobject = object; 950 tpindex = pindex; 951 shadowlookup: 952 /* 953 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 954 * and those pages must be OBJ_ONEMAPPING. 955 */ 956 if (advise == MADV_FREE) { 957 if ((tobject->type != OBJT_DEFAULT && 958 tobject->type != OBJT_SWAP) || 959 (tobject->flags & OBJ_ONEMAPPING) == 0) { 960 continue; 961 } 962 } 963 964 m = vm_page_lookup(tobject, tpindex); 965 966 if (m == NULL) { 967 /* 968 * There may be swap even if there is no backing page 969 */ 970 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 971 swap_pager_freespace(tobject, tpindex, 1); 972 973 /* 974 * next object 975 */ 976 tobject = tobject->backing_object; 977 if (tobject == NULL) 978 continue; 979 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 980 goto shadowlookup; 981 } 982 983 /* 984 * If the page is busy or not in a normal active state, 985 * we skip it. If the page is not managed there are no 986 * page queues to mess with. Things can break if we mess 987 * with pages in any of the below states. 988 */ 989 if ( 990 m->hold_count || 991 m->wire_count || 992 (m->flags & PG_UNMANAGED) || 993 m->valid != VM_PAGE_BITS_ALL 994 ) { 995 continue; 996 } 997 998 if (vm_page_sleep_busy(m, TRUE, "madvpo")) 999 goto relookup; 1000 1001 if (advise == MADV_WILLNEED) { 1002 vm_page_activate(m); 1003 } else if (advise == MADV_DONTNEED) { 1004 vm_page_dontneed(m); 1005 } else if (advise == MADV_FREE) { 1006 /* 1007 * Mark the page clean. This will allow the page 1008 * to be freed up by the system. However, such pages 1009 * are often reused quickly by malloc()/free() 1010 * so we do not do anything that would cause 1011 * a page fault if we can help it. 1012 * 1013 * Specifically, we do not try to actually free 1014 * the page now nor do we try to put it in the 1015 * cache (which would cause a page fault on reuse). 1016 * 1017 * But we do make the page is freeable as we 1018 * can without actually taking the step of unmapping 1019 * it. 1020 */ 1021 pmap_clear_modify(m); 1022 m->dirty = 0; 1023 m->act_count = 0; 1024 vm_page_dontneed(m); 1025 if (tobject->type == OBJT_SWAP) 1026 swap_pager_freespace(tobject, tpindex, 1); 1027 } 1028 } 1029 } 1030 1031 /* 1032 * vm_object_shadow: 1033 * 1034 * Create a new object which is backed by the 1035 * specified existing object range. The source 1036 * object reference is deallocated. 1037 * 1038 * The new object and offset into that object 1039 * are returned in the source parameters. 1040 */ 1041 1042 void 1043 vm_object_shadow(object, offset, length) 1044 vm_object_t *object; /* IN/OUT */ 1045 vm_ooffset_t *offset; /* IN/OUT */ 1046 vm_size_t length; 1047 { 1048 vm_object_t source; 1049 vm_object_t result; 1050 1051 source = *object; 1052 1053 /* 1054 * Don't create the new object if the old object isn't shared. 1055 */ 1056 1057 if (source != NULL && 1058 source->ref_count == 1 && 1059 source->handle == NULL && 1060 (source->type == OBJT_DEFAULT || 1061 source->type == OBJT_SWAP)) 1062 return; 1063 1064 /* 1065 * Allocate a new object with the given length 1066 */ 1067 1068 if ((result = vm_object_allocate(OBJT_DEFAULT, length)) == NULL) 1069 panic("vm_object_shadow: no object for shadowing"); 1070 1071 /* 1072 * The new object shadows the source object, adding a reference to it. 1073 * Our caller changes his reference to point to the new object, 1074 * removing a reference to the source object. Net result: no change 1075 * of reference count. 1076 * 1077 * Try to optimize the result object's page color when shadowing 1078 * in order to maintain page coloring consistency in the combined 1079 * shadowed object. 1080 */ 1081 result->backing_object = source; 1082 if (source) { 1083 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1084 source->shadow_count++; 1085 source->generation++; 1086 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & PQ_L2_MASK; 1087 } 1088 1089 /* 1090 * Store the offset into the source object, and fix up the offset into 1091 * the new object. 1092 */ 1093 1094 result->backing_object_offset = *offset; 1095 1096 /* 1097 * Return the new things 1098 */ 1099 1100 *offset = 0; 1101 *object = result; 1102 } 1103 1104 #define OBSC_TEST_ALL_SHADOWED 0x0001 1105 #define OBSC_COLLAPSE_NOWAIT 0x0002 1106 #define OBSC_COLLAPSE_WAIT 0x0004 1107 1108 static __inline int 1109 vm_object_backing_scan(vm_object_t object, int op) 1110 { 1111 int s; 1112 int r = 1; 1113 vm_page_t p; 1114 vm_object_t backing_object; 1115 vm_pindex_t backing_offset_index; 1116 1117 s = splvm(); 1118 1119 backing_object = object->backing_object; 1120 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1121 1122 /* 1123 * Initial conditions 1124 */ 1125 1126 if (op & OBSC_TEST_ALL_SHADOWED) { 1127 /* 1128 * We do not want to have to test for the existence of 1129 * swap pages in the backing object. XXX but with the 1130 * new swapper this would be pretty easy to do. 1131 * 1132 * XXX what about anonymous MAP_SHARED memory that hasn't 1133 * been ZFOD faulted yet? If we do not test for this, the 1134 * shadow test may succeed! XXX 1135 */ 1136 if (backing_object->type != OBJT_DEFAULT) { 1137 splx(s); 1138 return(0); 1139 } 1140 } 1141 if (op & OBSC_COLLAPSE_WAIT) { 1142 vm_object_set_flag(backing_object, OBJ_DEAD); 1143 } 1144 1145 /* 1146 * Our scan 1147 */ 1148 1149 p = TAILQ_FIRST(&backing_object->memq); 1150 while (p) { 1151 vm_page_t next = TAILQ_NEXT(p, listq); 1152 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1153 1154 if (op & OBSC_TEST_ALL_SHADOWED) { 1155 vm_page_t pp; 1156 1157 /* 1158 * Ignore pages outside the parent object's range 1159 * and outside the parent object's mapping of the 1160 * backing object. 1161 * 1162 * note that we do not busy the backing object's 1163 * page. 1164 */ 1165 1166 if ( 1167 p->pindex < backing_offset_index || 1168 new_pindex >= object->size 1169 ) { 1170 p = next; 1171 continue; 1172 } 1173 1174 /* 1175 * See if the parent has the page or if the parent's 1176 * object pager has the page. If the parent has the 1177 * page but the page is not valid, the parent's 1178 * object pager must have the page. 1179 * 1180 * If this fails, the parent does not completely shadow 1181 * the object and we might as well give up now. 1182 */ 1183 1184 pp = vm_page_lookup(object, new_pindex); 1185 if ( 1186 (pp == NULL || pp->valid == 0) && 1187 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1188 ) { 1189 r = 0; 1190 break; 1191 } 1192 } 1193 1194 /* 1195 * Check for busy page 1196 */ 1197 1198 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1199 vm_page_t pp; 1200 1201 if (op & OBSC_COLLAPSE_NOWAIT) { 1202 if ( 1203 (p->flags & PG_BUSY) || 1204 !p->valid || 1205 p->hold_count || 1206 p->wire_count || 1207 p->busy 1208 ) { 1209 p = next; 1210 continue; 1211 } 1212 } else if (op & OBSC_COLLAPSE_WAIT) { 1213 if (vm_page_sleep_busy(p, TRUE, "vmocol")) { 1214 /* 1215 * If we slept, anything could have 1216 * happened. Since the object is 1217 * marked dead, the backing offset 1218 * should not have changed so we 1219 * just restart our scan. 1220 */ 1221 p = TAILQ_FIRST(&backing_object->memq); 1222 continue; 1223 } 1224 } 1225 1226 /* 1227 * Busy the page 1228 */ 1229 vm_page_busy(p); 1230 1231 KASSERT( 1232 p->object == backing_object, 1233 ("vm_object_qcollapse(): object mismatch") 1234 ); 1235 1236 /* 1237 * Destroy any associated swap 1238 */ 1239 if (backing_object->type == OBJT_SWAP) { 1240 swap_pager_freespace( 1241 backing_object, 1242 p->pindex, 1243 1 1244 ); 1245 } 1246 1247 if ( 1248 p->pindex < backing_offset_index || 1249 new_pindex >= object->size 1250 ) { 1251 /* 1252 * Page is out of the parent object's range, we 1253 * can simply destroy it. 1254 */ 1255 vm_page_protect(p, VM_PROT_NONE); 1256 vm_page_free(p); 1257 p = next; 1258 continue; 1259 } 1260 1261 pp = vm_page_lookup(object, new_pindex); 1262 if ( 1263 pp != NULL || 1264 vm_pager_has_page(object, new_pindex, NULL, NULL) 1265 ) { 1266 /* 1267 * page already exists in parent OR swap exists 1268 * for this location in the parent. Destroy 1269 * the original page from the backing object. 1270 * 1271 * Leave the parent's page alone 1272 */ 1273 vm_page_protect(p, VM_PROT_NONE); 1274 vm_page_free(p); 1275 p = next; 1276 continue; 1277 } 1278 1279 /* 1280 * Page does not exist in parent, rename the 1281 * page from the backing object to the main object. 1282 * 1283 * If the page was mapped to a process, it can remain 1284 * mapped through the rename. 1285 */ 1286 if ((p->queue - p->pc) == PQ_CACHE) 1287 vm_page_deactivate(p); 1288 1289 vm_page_rename(p, object, new_pindex); 1290 /* page automatically made dirty by rename */ 1291 } 1292 p = next; 1293 } 1294 splx(s); 1295 return(r); 1296 } 1297 1298 1299 /* 1300 * this version of collapse allows the operation to occur earlier and 1301 * when paging_in_progress is true for an object... This is not a complete 1302 * operation, but should plug 99.9% of the rest of the leaks. 1303 */ 1304 static void 1305 vm_object_qcollapse(object) 1306 vm_object_t object; 1307 { 1308 vm_object_t backing_object = object->backing_object; 1309 1310 if (backing_object->ref_count != 1) 1311 return; 1312 1313 backing_object->ref_count += 2; 1314 1315 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1316 1317 backing_object->ref_count -= 2; 1318 } 1319 1320 /* 1321 * vm_object_collapse: 1322 * 1323 * Collapse an object with the object backing it. 1324 * Pages in the backing object are moved into the 1325 * parent, and the backing object is deallocated. 1326 */ 1327 void 1328 vm_object_collapse(object) 1329 vm_object_t object; 1330 { 1331 while (TRUE) { 1332 vm_object_t backing_object; 1333 1334 /* 1335 * Verify that the conditions are right for collapse: 1336 * 1337 * The object exists and the backing object exists. 1338 */ 1339 if (object == NULL) 1340 break; 1341 1342 if ((backing_object = object->backing_object) == NULL) 1343 break; 1344 1345 /* 1346 * we check the backing object first, because it is most likely 1347 * not collapsable. 1348 */ 1349 if (backing_object->handle != NULL || 1350 (backing_object->type != OBJT_DEFAULT && 1351 backing_object->type != OBJT_SWAP) || 1352 (backing_object->flags & OBJ_DEAD) || 1353 object->handle != NULL || 1354 (object->type != OBJT_DEFAULT && 1355 object->type != OBJT_SWAP) || 1356 (object->flags & OBJ_DEAD)) { 1357 break; 1358 } 1359 1360 if ( 1361 object->paging_in_progress != 0 || 1362 backing_object->paging_in_progress != 0 1363 ) { 1364 vm_object_qcollapse(object); 1365 break; 1366 } 1367 1368 /* 1369 * We know that we can either collapse the backing object (if 1370 * the parent is the only reference to it) or (perhaps) have 1371 * the parent bypass the object if the parent happens to shadow 1372 * all the resident pages in the entire backing object. 1373 * 1374 * This is ignoring pager-backed pages such as swap pages. 1375 * vm_object_backing_scan fails the shadowing test in this 1376 * case. 1377 */ 1378 1379 if (backing_object->ref_count == 1) { 1380 /* 1381 * If there is exactly one reference to the backing 1382 * object, we can collapse it into the parent. 1383 */ 1384 1385 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1386 1387 /* 1388 * Move the pager from backing_object to object. 1389 */ 1390 1391 if (backing_object->type == OBJT_SWAP) { 1392 vm_object_pip_add(backing_object, 1); 1393 1394 /* 1395 * scrap the paging_offset junk and do a 1396 * discrete copy. This also removes major 1397 * assumptions about how the swap-pager 1398 * works from where it doesn't belong. The 1399 * new swapper is able to optimize the 1400 * destroy-source case. 1401 */ 1402 1403 vm_object_pip_add(object, 1); 1404 swap_pager_copy( 1405 backing_object, 1406 object, 1407 OFF_TO_IDX(object->backing_object_offset), TRUE); 1408 vm_object_pip_wakeup(object); 1409 1410 vm_object_pip_wakeup(backing_object); 1411 } 1412 /* 1413 * Object now shadows whatever backing_object did. 1414 * Note that the reference to 1415 * backing_object->backing_object moves from within 1416 * backing_object to within object. 1417 */ 1418 1419 LIST_REMOVE(object, shadow_list); 1420 object->backing_object->shadow_count--; 1421 object->backing_object->generation++; 1422 if (backing_object->backing_object) { 1423 LIST_REMOVE(backing_object, shadow_list); 1424 backing_object->backing_object->shadow_count--; 1425 backing_object->backing_object->generation++; 1426 } 1427 object->backing_object = backing_object->backing_object; 1428 if (object->backing_object) { 1429 LIST_INSERT_HEAD( 1430 &object->backing_object->shadow_head, 1431 object, 1432 shadow_list 1433 ); 1434 object->backing_object->shadow_count++; 1435 object->backing_object->generation++; 1436 } 1437 1438 object->backing_object_offset += 1439 backing_object->backing_object_offset; 1440 1441 /* 1442 * Discard backing_object. 1443 * 1444 * Since the backing object has no pages, no pager left, 1445 * and no object references within it, all that is 1446 * necessary is to dispose of it. 1447 */ 1448 1449 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1450 KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object)); 1451 TAILQ_REMOVE( 1452 &vm_object_list, 1453 backing_object, 1454 object_list 1455 ); 1456 vm_object_count--; 1457 1458 zfree(obj_zone, backing_object); 1459 1460 object_collapses++; 1461 } else { 1462 vm_object_t new_backing_object; 1463 1464 /* 1465 * If we do not entirely shadow the backing object, 1466 * there is nothing we can do so we give up. 1467 */ 1468 1469 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1470 break; 1471 } 1472 1473 /* 1474 * Make the parent shadow the next object in the 1475 * chain. Deallocating backing_object will not remove 1476 * it, since its reference count is at least 2. 1477 */ 1478 1479 LIST_REMOVE(object, shadow_list); 1480 backing_object->shadow_count--; 1481 backing_object->generation++; 1482 1483 new_backing_object = backing_object->backing_object; 1484 if ((object->backing_object = new_backing_object) != NULL) { 1485 vm_object_reference(new_backing_object); 1486 LIST_INSERT_HEAD( 1487 &new_backing_object->shadow_head, 1488 object, 1489 shadow_list 1490 ); 1491 new_backing_object->shadow_count++; 1492 new_backing_object->generation++; 1493 object->backing_object_offset += 1494 backing_object->backing_object_offset; 1495 } 1496 1497 /* 1498 * Drop the reference count on backing_object. Since 1499 * its ref_count was at least 2, it will not vanish; 1500 * so we don't need to call vm_object_deallocate, but 1501 * we do anyway. 1502 */ 1503 vm_object_deallocate(backing_object); 1504 object_bypasses++; 1505 } 1506 1507 /* 1508 * Try again with this object's new backing object. 1509 */ 1510 } 1511 } 1512 1513 /* 1514 * vm_object_page_remove: [internal] 1515 * 1516 * Removes all physical pages in the specified 1517 * object range from the object's list of pages. 1518 * 1519 * The object must be locked. 1520 */ 1521 void 1522 vm_object_page_remove(object, start, end, clean_only) 1523 vm_object_t object; 1524 vm_pindex_t start; 1525 vm_pindex_t end; 1526 boolean_t clean_only; 1527 { 1528 vm_page_t p, next; 1529 unsigned int size; 1530 int all; 1531 1532 if (object == NULL || 1533 object->resident_page_count == 0) 1534 return; 1535 1536 all = ((end == 0) && (start == 0)); 1537 1538 /* 1539 * Since physically-backed objects do not use managed pages, we can't 1540 * remove pages from the object (we must instead remove the page 1541 * references, and then destroy the object). 1542 */ 1543 KASSERT(object->type != OBJT_PHYS, ("attempt to remove pages from a physical object")); 1544 1545 vm_object_pip_add(object, 1); 1546 again: 1547 size = end - start; 1548 if (all || size > object->resident_page_count / 4) { 1549 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = next) { 1550 next = TAILQ_NEXT(p, listq); 1551 if (all || ((start <= p->pindex) && (p->pindex < end))) { 1552 if (p->wire_count != 0) { 1553 vm_page_protect(p, VM_PROT_NONE); 1554 if (!clean_only) 1555 p->valid = 0; 1556 continue; 1557 } 1558 1559 /* 1560 * The busy flags are only cleared at 1561 * interrupt -- minimize the spl transitions 1562 */ 1563 1564 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1565 goto again; 1566 1567 if (clean_only && p->valid) { 1568 vm_page_test_dirty(p); 1569 if (p->valid & p->dirty) 1570 continue; 1571 } 1572 1573 vm_page_busy(p); 1574 vm_page_protect(p, VM_PROT_NONE); 1575 vm_page_free(p); 1576 } 1577 } 1578 } else { 1579 while (size > 0) { 1580 if ((p = vm_page_lookup(object, start)) != 0) { 1581 1582 if (p->wire_count != 0) { 1583 vm_page_protect(p, VM_PROT_NONE); 1584 if (!clean_only) 1585 p->valid = 0; 1586 start += 1; 1587 size -= 1; 1588 continue; 1589 } 1590 1591 /* 1592 * The busy flags are only cleared at 1593 * interrupt -- minimize the spl transitions 1594 */ 1595 if (vm_page_sleep_busy(p, TRUE, "vmopar")) 1596 goto again; 1597 1598 if (clean_only && p->valid) { 1599 vm_page_test_dirty(p); 1600 if (p->valid & p->dirty) { 1601 start += 1; 1602 size -= 1; 1603 continue; 1604 } 1605 } 1606 1607 vm_page_busy(p); 1608 vm_page_protect(p, VM_PROT_NONE); 1609 vm_page_free(p); 1610 } 1611 start += 1; 1612 size -= 1; 1613 } 1614 } 1615 vm_object_pip_wakeup(object); 1616 } 1617 1618 /* 1619 * Routine: vm_object_coalesce 1620 * Function: Coalesces two objects backing up adjoining 1621 * regions of memory into a single object. 1622 * 1623 * returns TRUE if objects were combined. 1624 * 1625 * NOTE: Only works at the moment if the second object is NULL - 1626 * if it's not, which object do we lock first? 1627 * 1628 * Parameters: 1629 * prev_object First object to coalesce 1630 * prev_offset Offset into prev_object 1631 * next_object Second object into coalesce 1632 * next_offset Offset into next_object 1633 * 1634 * prev_size Size of reference to prev_object 1635 * next_size Size of reference to next_object 1636 * 1637 * Conditions: 1638 * The object must *not* be locked. 1639 */ 1640 boolean_t 1641 vm_object_coalesce(prev_object, prev_pindex, prev_size, next_size) 1642 vm_object_t prev_object; 1643 vm_pindex_t prev_pindex; 1644 vm_size_t prev_size, next_size; 1645 { 1646 vm_pindex_t next_pindex; 1647 1648 if (prev_object == NULL) { 1649 return (TRUE); 1650 } 1651 1652 if (prev_object->type != OBJT_DEFAULT && 1653 prev_object->type != OBJT_SWAP) { 1654 return (FALSE); 1655 } 1656 1657 /* 1658 * Try to collapse the object first 1659 */ 1660 vm_object_collapse(prev_object); 1661 1662 /* 1663 * Can't coalesce if: . more than one reference . paged out . shadows 1664 * another object . has a copy elsewhere (any of which mean that the 1665 * pages not mapped to prev_entry may be in use anyway) 1666 */ 1667 1668 if (prev_object->backing_object != NULL) { 1669 return (FALSE); 1670 } 1671 1672 prev_size >>= PAGE_SHIFT; 1673 next_size >>= PAGE_SHIFT; 1674 next_pindex = prev_pindex + prev_size; 1675 1676 if ((prev_object->ref_count > 1) && 1677 (prev_object->size != next_pindex)) { 1678 return (FALSE); 1679 } 1680 1681 /* 1682 * Remove any pages that may still be in the object from a previous 1683 * deallocation. 1684 */ 1685 if (next_pindex < prev_object->size) { 1686 vm_object_page_remove(prev_object, 1687 next_pindex, 1688 next_pindex + next_size, FALSE); 1689 if (prev_object->type == OBJT_SWAP) 1690 swap_pager_freespace(prev_object, 1691 next_pindex, next_size); 1692 } 1693 1694 /* 1695 * Extend the object if necessary. 1696 */ 1697 if (next_pindex + next_size > prev_object->size) 1698 prev_object->size = next_pindex + next_size; 1699 1700 return (TRUE); 1701 } 1702 1703 void 1704 vm_object_set_writeable_dirty(vm_object_t object) 1705 { 1706 struct vnode *vp; 1707 1708 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1709 if (object->type == OBJT_VNODE && 1710 (vp = (struct vnode *)object->handle) != NULL) { 1711 if ((vp->v_flag & VOBJDIRTY) == 0) { 1712 lwkt_gettoken(&vp->v_interlock); 1713 vp->v_flag |= VOBJDIRTY; 1714 lwkt_reltoken(&vp->v_interlock); 1715 } 1716 } 1717 } 1718 1719 1720 1721 #include "opt_ddb.h" 1722 #ifdef DDB 1723 #include <sys/kernel.h> 1724 1725 #include <sys/cons.h> 1726 1727 #include <ddb/ddb.h> 1728 1729 static int _vm_object_in_map __P((vm_map_t map, vm_object_t object, 1730 vm_map_entry_t entry)); 1731 static int vm_object_in_map __P((vm_object_t object)); 1732 1733 static int 1734 _vm_object_in_map(map, object, entry) 1735 vm_map_t map; 1736 vm_object_t object; 1737 vm_map_entry_t entry; 1738 { 1739 vm_map_t tmpm; 1740 vm_map_entry_t tmpe; 1741 vm_object_t obj; 1742 int entcount; 1743 1744 if (map == 0) 1745 return 0; 1746 1747 if (entry == 0) { 1748 tmpe = map->header.next; 1749 entcount = map->nentries; 1750 while (entcount-- && (tmpe != &map->header)) { 1751 if( _vm_object_in_map(map, object, tmpe)) { 1752 return 1; 1753 } 1754 tmpe = tmpe->next; 1755 } 1756 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1757 tmpm = entry->object.sub_map; 1758 tmpe = tmpm->header.next; 1759 entcount = tmpm->nentries; 1760 while (entcount-- && tmpe != &tmpm->header) { 1761 if( _vm_object_in_map(tmpm, object, tmpe)) { 1762 return 1; 1763 } 1764 tmpe = tmpe->next; 1765 } 1766 } else if ((obj = entry->object.vm_object) != NULL) { 1767 for(; obj; obj=obj->backing_object) 1768 if( obj == object) { 1769 return 1; 1770 } 1771 } 1772 return 0; 1773 } 1774 1775 static int 1776 vm_object_in_map( object) 1777 vm_object_t object; 1778 { 1779 struct proc *p; 1780 for (p = allproc.lh_first; p != 0; p = p->p_list.le_next) { 1781 if( !p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1782 continue; 1783 if( _vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) 1784 return 1; 1785 } 1786 if( _vm_object_in_map( kernel_map, object, 0)) 1787 return 1; 1788 if( _vm_object_in_map( kmem_map, object, 0)) 1789 return 1; 1790 if( _vm_object_in_map( pager_map, object, 0)) 1791 return 1; 1792 if( _vm_object_in_map( buffer_map, object, 0)) 1793 return 1; 1794 if( _vm_object_in_map( mb_map, object, 0)) 1795 return 1; 1796 return 0; 1797 } 1798 1799 DB_SHOW_COMMAND(vmochk, vm_object_check) 1800 { 1801 vm_object_t object; 1802 1803 /* 1804 * make sure that internal objs are in a map somewhere 1805 * and none have zero ref counts. 1806 */ 1807 for (object = TAILQ_FIRST(&vm_object_list); 1808 object != NULL; 1809 object = TAILQ_NEXT(object, object_list)) { 1810 if (object->handle == NULL && 1811 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1812 if (object->ref_count == 0) { 1813 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1814 (long)object->size); 1815 } 1816 if (!vm_object_in_map(object)) { 1817 db_printf( 1818 "vmochk: internal obj is not in a map: " 1819 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1820 object->ref_count, (u_long)object->size, 1821 (u_long)object->size, 1822 (void *)object->backing_object); 1823 } 1824 } 1825 } 1826 } 1827 1828 /* 1829 * vm_object_print: [ debug ] 1830 */ 1831 DB_SHOW_COMMAND(object, vm_object_print_static) 1832 { 1833 /* XXX convert args. */ 1834 vm_object_t object = (vm_object_t)addr; 1835 boolean_t full = have_addr; 1836 1837 vm_page_t p; 1838 1839 /* XXX count is an (unused) arg. Avoid shadowing it. */ 1840 #define count was_count 1841 1842 int count; 1843 1844 if (object == NULL) 1845 return; 1846 1847 db_iprintf( 1848 "Object %p: type=%d, size=0x%lx, res=%d, ref=%d, flags=0x%x\n", 1849 object, (int)object->type, (u_long)object->size, 1850 object->resident_page_count, object->ref_count, object->flags); 1851 /* 1852 * XXX no %qd in kernel. Truncate object->backing_object_offset. 1853 */ 1854 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%lx\n", 1855 object->shadow_count, 1856 object->backing_object ? object->backing_object->ref_count : 0, 1857 object->backing_object, (long)object->backing_object_offset); 1858 1859 if (!full) 1860 return; 1861 1862 db_indent += 2; 1863 count = 0; 1864 for (p = TAILQ_FIRST(&object->memq); p != NULL; p = TAILQ_NEXT(p, listq)) { 1865 if (count == 0) 1866 db_iprintf("memory:="); 1867 else if (count == 6) { 1868 db_printf("\n"); 1869 db_iprintf(" ..."); 1870 count = 0; 1871 } else 1872 db_printf(","); 1873 count++; 1874 1875 db_printf("(off=0x%lx,page=0x%lx)", 1876 (u_long) p->pindex, (u_long) VM_PAGE_TO_PHYS(p)); 1877 } 1878 if (count != 0) 1879 db_printf("\n"); 1880 db_indent -= 2; 1881 } 1882 1883 /* XXX. */ 1884 #undef count 1885 1886 /* XXX need this non-static entry for calling from vm_map_print. */ 1887 void 1888 vm_object_print(addr, have_addr, count, modif) 1889 /* db_expr_t */ long addr; 1890 boolean_t have_addr; 1891 /* db_expr_t */ long count; 1892 char *modif; 1893 { 1894 vm_object_print_static(addr, have_addr, count, modif); 1895 } 1896 1897 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 1898 { 1899 vm_object_t object; 1900 int nl = 0; 1901 int c; 1902 for (object = TAILQ_FIRST(&vm_object_list); 1903 object != NULL; 1904 object = TAILQ_NEXT(object, object_list)) { 1905 vm_pindex_t idx, fidx; 1906 vm_pindex_t osize; 1907 vm_offset_t pa = -1, padiff; 1908 int rcount; 1909 vm_page_t m; 1910 1911 db_printf("new object: %p\n", (void *)object); 1912 if ( nl > 18) { 1913 c = cngetc(); 1914 if (c != ' ') 1915 return; 1916 nl = 0; 1917 } 1918 nl++; 1919 rcount = 0; 1920 fidx = 0; 1921 osize = object->size; 1922 if (osize > 128) 1923 osize = 128; 1924 for(idx=0;idx<osize;idx++) { 1925 m = vm_page_lookup(object, idx); 1926 if (m == NULL) { 1927 if (rcount) { 1928 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1929 (long)fidx, rcount, (long)pa); 1930 if ( nl > 18) { 1931 c = cngetc(); 1932 if (c != ' ') 1933 return; 1934 nl = 0; 1935 } 1936 nl++; 1937 rcount = 0; 1938 } 1939 continue; 1940 } 1941 1942 1943 if (rcount && 1944 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 1945 ++rcount; 1946 continue; 1947 } 1948 if (rcount) { 1949 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 1950 padiff >>= PAGE_SHIFT; 1951 padiff &= PQ_L2_MASK; 1952 if (padiff == 0) { 1953 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 1954 ++rcount; 1955 continue; 1956 } 1957 db_printf(" index(%ld)run(%d)pa(0x%lx)", 1958 (long)fidx, rcount, (long)pa); 1959 db_printf("pd(%ld)\n", (long)padiff); 1960 if ( nl > 18) { 1961 c = cngetc(); 1962 if (c != ' ') 1963 return; 1964 nl = 0; 1965 } 1966 nl++; 1967 } 1968 fidx = idx; 1969 pa = VM_PAGE_TO_PHYS(m); 1970 rcount = 1; 1971 } 1972 if (rcount) { 1973 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 1974 (long)fidx, rcount, (long)pa); 1975 if ( nl > 18) { 1976 c = cngetc(); 1977 if (c != ' ') 1978 return; 1979 nl = 0; 1980 } 1981 nl++; 1982 } 1983 } 1984 } 1985 #endif /* DDB */ 1986