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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Virtual memory object module. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include "opt_vm.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/lock.h> 73 #include <sys/mman.h> 74 #include <sys/mount.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 #include <sys/mutex.h> 78 #include <sys/proc.h> /* for curproc, pageproc */ 79 #include <sys/socket.h> 80 #include <sys/resourcevar.h> 81 #include <sys/vnode.h> 82 #include <sys/vmmeter.h> 83 #include <sys/sx.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_page.h> 91 #include <vm/vm_pageout.h> 92 #include <vm/vm_pager.h> 93 #include <vm/swap_pager.h> 94 #include <vm/vm_kern.h> 95 #include <vm/vm_extern.h> 96 #include <vm/vm_reserv.h> 97 #include <vm/uma.h> 98 99 #define EASY_SCAN_FACTOR 8 100 101 #define MSYNC_FLUSH_HARDSEQ 0x01 102 #define MSYNC_FLUSH_SOFTSEQ 0x02 103 104 /* 105 * msync / VM object flushing optimizations 106 */ 107 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 108 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, CTLFLAG_RW, &msync_flush_flags, 0, 109 "Enable sequential iteration optimization"); 110 111 static int old_msync; 112 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 113 "Use old (insecure) msync behavior"); 114 115 static void vm_object_qcollapse(vm_object_t object); 116 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 117 static void vm_object_vndeallocate(vm_object_t object); 118 119 /* 120 * Virtual memory objects maintain the actual data 121 * associated with allocated virtual memory. A given 122 * page of memory exists within exactly one object. 123 * 124 * An object is only deallocated when all "references" 125 * are given up. Only one "reference" to a given 126 * region of an object should be writeable. 127 * 128 * Associated with each object is a list of all resident 129 * memory pages belonging to that object; this list is 130 * maintained by the "vm_page" module, and locked by the object's 131 * lock. 132 * 133 * Each object also records a "pager" routine which is 134 * used to retrieve (and store) pages to the proper backing 135 * storage. In addition, objects may be backed by other 136 * objects from which they were virtual-copied. 137 * 138 * The only items within the object structure which are 139 * modified after time of creation are: 140 * reference count locked by object's lock 141 * pager routine locked by object's lock 142 * 143 */ 144 145 struct object_q vm_object_list; 146 struct mtx vm_object_list_mtx; /* lock for object list and count */ 147 148 struct vm_object kernel_object_store; 149 struct vm_object kmem_object_store; 150 151 SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0, "VM object stats"); 152 153 static long object_collapses; 154 SYSCTL_LONG(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, 155 &object_collapses, 0, "VM object collapses"); 156 157 static long object_bypasses; 158 SYSCTL_LONG(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, 159 &object_bypasses, 0, "VM object bypasses"); 160 161 static uma_zone_t obj_zone; 162 163 static int vm_object_zinit(void *mem, int size, int flags); 164 165 #ifdef INVARIANTS 166 static void vm_object_zdtor(void *mem, int size, void *arg); 167 168 static void 169 vm_object_zdtor(void *mem, int size, void *arg) 170 { 171 vm_object_t object; 172 173 object = (vm_object_t)mem; 174 KASSERT(TAILQ_EMPTY(&object->memq), 175 ("object %p has resident pages", 176 object)); 177 #if VM_NRESERVLEVEL > 0 178 KASSERT(LIST_EMPTY(&object->rvq), 179 ("object %p has reservations", 180 object)); 181 #endif 182 KASSERT(object->cache == NULL, 183 ("object %p has cached pages", 184 object)); 185 KASSERT(object->paging_in_progress == 0, 186 ("object %p paging_in_progress = %d", 187 object, object->paging_in_progress)); 188 KASSERT(object->resident_page_count == 0, 189 ("object %p resident_page_count = %d", 190 object, object->resident_page_count)); 191 KASSERT(object->shadow_count == 0, 192 ("object %p shadow_count = %d", 193 object, object->shadow_count)); 194 } 195 #endif 196 197 static int 198 vm_object_zinit(void *mem, int size, int flags) 199 { 200 vm_object_t object; 201 202 object = (vm_object_t)mem; 203 bzero(&object->mtx, sizeof(object->mtx)); 204 VM_OBJECT_LOCK_INIT(object, "standard object"); 205 206 /* These are true for any object that has been freed */ 207 object->paging_in_progress = 0; 208 object->resident_page_count = 0; 209 object->shadow_count = 0; 210 return (0); 211 } 212 213 void 214 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object) 215 { 216 217 TAILQ_INIT(&object->memq); 218 LIST_INIT(&object->shadow_head); 219 220 object->root = NULL; 221 object->type = type; 222 object->size = size; 223 object->generation = 1; 224 object->ref_count = 1; 225 object->memattr = VM_MEMATTR_DEFAULT; 226 object->flags = 0; 227 object->uip = NULL; 228 object->charge = 0; 229 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 230 object->flags = OBJ_ONEMAPPING; 231 object->pg_color = 0; 232 object->handle = NULL; 233 object->backing_object = NULL; 234 object->backing_object_offset = (vm_ooffset_t) 0; 235 #if VM_NRESERVLEVEL > 0 236 LIST_INIT(&object->rvq); 237 #endif 238 object->cache = NULL; 239 240 mtx_lock(&vm_object_list_mtx); 241 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 242 mtx_unlock(&vm_object_list_mtx); 243 } 244 245 /* 246 * vm_object_init: 247 * 248 * Initialize the VM objects module. 249 */ 250 void 251 vm_object_init(void) 252 { 253 TAILQ_INIT(&vm_object_list); 254 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 255 256 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object"); 257 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 258 kernel_object); 259 #if VM_NRESERVLEVEL > 0 260 kernel_object->flags |= OBJ_COLORED; 261 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 262 #endif 263 264 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object"); 265 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 266 kmem_object); 267 #if VM_NRESERVLEVEL > 0 268 kmem_object->flags |= OBJ_COLORED; 269 kmem_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 270 #endif 271 272 /* 273 * The lock portion of struct vm_object must be type stable due 274 * to vm_pageout_fallback_object_lock locking a vm object 275 * without holding any references to it. 276 */ 277 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 278 #ifdef INVARIANTS 279 vm_object_zdtor, 280 #else 281 NULL, 282 #endif 283 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 284 } 285 286 void 287 vm_object_clear_flag(vm_object_t object, u_short bits) 288 { 289 290 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 291 object->flags &= ~bits; 292 } 293 294 /* 295 * Sets the default memory attribute for the specified object. Pages 296 * that are allocated to this object are by default assigned this memory 297 * attribute. 298 * 299 * Presently, this function must be called before any pages are allocated 300 * to the object. In the future, this requirement may be relaxed for 301 * "default" and "swap" objects. 302 */ 303 int 304 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr) 305 { 306 307 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 308 switch (object->type) { 309 case OBJT_DEFAULT: 310 case OBJT_DEVICE: 311 case OBJT_PHYS: 312 case OBJT_SG: 313 case OBJT_SWAP: 314 case OBJT_VNODE: 315 if (!TAILQ_EMPTY(&object->memq)) 316 return (KERN_FAILURE); 317 break; 318 case OBJT_DEAD: 319 return (KERN_INVALID_ARGUMENT); 320 } 321 object->memattr = memattr; 322 return (KERN_SUCCESS); 323 } 324 325 void 326 vm_object_pip_add(vm_object_t object, short i) 327 { 328 329 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 330 object->paging_in_progress += i; 331 } 332 333 void 334 vm_object_pip_subtract(vm_object_t object, short i) 335 { 336 337 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 338 object->paging_in_progress -= i; 339 } 340 341 void 342 vm_object_pip_wakeup(vm_object_t object) 343 { 344 345 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 346 object->paging_in_progress--; 347 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 348 vm_object_clear_flag(object, OBJ_PIPWNT); 349 wakeup(object); 350 } 351 } 352 353 void 354 vm_object_pip_wakeupn(vm_object_t object, short i) 355 { 356 357 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 358 if (i) 359 object->paging_in_progress -= i; 360 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 361 vm_object_clear_flag(object, OBJ_PIPWNT); 362 wakeup(object); 363 } 364 } 365 366 void 367 vm_object_pip_wait(vm_object_t object, char *waitid) 368 { 369 370 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 371 while (object->paging_in_progress) { 372 object->flags |= OBJ_PIPWNT; 373 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 374 } 375 } 376 377 /* 378 * vm_object_allocate: 379 * 380 * Returns a new object with the given size. 381 */ 382 vm_object_t 383 vm_object_allocate(objtype_t type, vm_pindex_t size) 384 { 385 vm_object_t object; 386 387 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 388 _vm_object_allocate(type, size, object); 389 return (object); 390 } 391 392 393 /* 394 * vm_object_reference: 395 * 396 * Gets another reference to the given object. Note: OBJ_DEAD 397 * objects can be referenced during final cleaning. 398 */ 399 void 400 vm_object_reference(vm_object_t object) 401 { 402 if (object == NULL) 403 return; 404 VM_OBJECT_LOCK(object); 405 vm_object_reference_locked(object); 406 VM_OBJECT_UNLOCK(object); 407 } 408 409 /* 410 * vm_object_reference_locked: 411 * 412 * Gets another reference to the given object. 413 * 414 * The object must be locked. 415 */ 416 void 417 vm_object_reference_locked(vm_object_t object) 418 { 419 struct vnode *vp; 420 421 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 422 object->ref_count++; 423 if (object->type == OBJT_VNODE) { 424 vp = object->handle; 425 vref(vp); 426 } 427 } 428 429 /* 430 * Handle deallocating an object of type OBJT_VNODE. 431 */ 432 static void 433 vm_object_vndeallocate(vm_object_t object) 434 { 435 struct vnode *vp = (struct vnode *) object->handle; 436 437 VFS_ASSERT_GIANT(vp->v_mount); 438 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 439 KASSERT(object->type == OBJT_VNODE, 440 ("vm_object_vndeallocate: not a vnode object")); 441 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 442 #ifdef INVARIANTS 443 if (object->ref_count == 0) { 444 vprint("vm_object_vndeallocate", vp); 445 panic("vm_object_vndeallocate: bad object reference count"); 446 } 447 #endif 448 449 object->ref_count--; 450 if (object->ref_count == 0) { 451 mp_fixme("Unlocked vflag access."); 452 vp->v_vflag &= ~VV_TEXT; 453 } 454 VM_OBJECT_UNLOCK(object); 455 /* 456 * vrele may need a vop lock 457 */ 458 vrele(vp); 459 } 460 461 /* 462 * vm_object_deallocate: 463 * 464 * Release a reference to the specified object, 465 * gained either through a vm_object_allocate 466 * or a vm_object_reference call. When all references 467 * are gone, storage associated with this object 468 * may be relinquished. 469 * 470 * No object may be locked. 471 */ 472 void 473 vm_object_deallocate(vm_object_t object) 474 { 475 vm_object_t temp; 476 477 while (object != NULL) { 478 int vfslocked; 479 480 vfslocked = 0; 481 restart: 482 VM_OBJECT_LOCK(object); 483 if (object->type == OBJT_VNODE) { 484 struct vnode *vp = (struct vnode *) object->handle; 485 486 /* 487 * Conditionally acquire Giant for a vnode-backed 488 * object. We have to be careful since the type of 489 * a vnode object can change while the object is 490 * unlocked. 491 */ 492 if (VFS_NEEDSGIANT(vp->v_mount) && !vfslocked) { 493 vfslocked = 1; 494 if (!mtx_trylock(&Giant)) { 495 VM_OBJECT_UNLOCK(object); 496 mtx_lock(&Giant); 497 goto restart; 498 } 499 } 500 vm_object_vndeallocate(object); 501 VFS_UNLOCK_GIANT(vfslocked); 502 return; 503 } else 504 /* 505 * This is to handle the case that the object 506 * changed type while we dropped its lock to 507 * obtain Giant. 508 */ 509 VFS_UNLOCK_GIANT(vfslocked); 510 511 KASSERT(object->ref_count != 0, 512 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 513 514 /* 515 * If the reference count goes to 0 we start calling 516 * vm_object_terminate() on the object chain. 517 * A ref count of 1 may be a special case depending on the 518 * shadow count being 0 or 1. 519 */ 520 object->ref_count--; 521 if (object->ref_count > 1) { 522 VM_OBJECT_UNLOCK(object); 523 return; 524 } else if (object->ref_count == 1) { 525 if (object->shadow_count == 0 && 526 object->handle == NULL && 527 (object->type == OBJT_DEFAULT || 528 object->type == OBJT_SWAP)) { 529 vm_object_set_flag(object, OBJ_ONEMAPPING); 530 } else if ((object->shadow_count == 1) && 531 (object->handle == NULL) && 532 (object->type == OBJT_DEFAULT || 533 object->type == OBJT_SWAP)) { 534 vm_object_t robject; 535 536 robject = LIST_FIRST(&object->shadow_head); 537 KASSERT(robject != NULL, 538 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 539 object->ref_count, 540 object->shadow_count)); 541 if (!VM_OBJECT_TRYLOCK(robject)) { 542 /* 543 * Avoid a potential deadlock. 544 */ 545 object->ref_count++; 546 VM_OBJECT_UNLOCK(object); 547 /* 548 * More likely than not the thread 549 * holding robject's lock has lower 550 * priority than the current thread. 551 * Let the lower priority thread run. 552 */ 553 pause("vmo_de", 1); 554 continue; 555 } 556 /* 557 * Collapse object into its shadow unless its 558 * shadow is dead. In that case, object will 559 * be deallocated by the thread that is 560 * deallocating its shadow. 561 */ 562 if ((robject->flags & OBJ_DEAD) == 0 && 563 (robject->handle == NULL) && 564 (robject->type == OBJT_DEFAULT || 565 robject->type == OBJT_SWAP)) { 566 567 robject->ref_count++; 568 retry: 569 if (robject->paging_in_progress) { 570 VM_OBJECT_UNLOCK(object); 571 vm_object_pip_wait(robject, 572 "objde1"); 573 temp = robject->backing_object; 574 if (object == temp) { 575 VM_OBJECT_LOCK(object); 576 goto retry; 577 } 578 } else if (object->paging_in_progress) { 579 VM_OBJECT_UNLOCK(robject); 580 object->flags |= OBJ_PIPWNT; 581 msleep(object, 582 VM_OBJECT_MTX(object), 583 PDROP | PVM, "objde2", 0); 584 VM_OBJECT_LOCK(robject); 585 temp = robject->backing_object; 586 if (object == temp) { 587 VM_OBJECT_LOCK(object); 588 goto retry; 589 } 590 } else 591 VM_OBJECT_UNLOCK(object); 592 593 if (robject->ref_count == 1) { 594 robject->ref_count--; 595 object = robject; 596 goto doterm; 597 } 598 object = robject; 599 vm_object_collapse(object); 600 VM_OBJECT_UNLOCK(object); 601 continue; 602 } 603 VM_OBJECT_UNLOCK(robject); 604 } 605 VM_OBJECT_UNLOCK(object); 606 return; 607 } 608 doterm: 609 temp = object->backing_object; 610 if (temp != NULL) { 611 VM_OBJECT_LOCK(temp); 612 LIST_REMOVE(object, shadow_list); 613 temp->shadow_count--; 614 temp->generation++; 615 VM_OBJECT_UNLOCK(temp); 616 object->backing_object = NULL; 617 } 618 /* 619 * Don't double-terminate, we could be in a termination 620 * recursion due to the terminate having to sync data 621 * to disk. 622 */ 623 if ((object->flags & OBJ_DEAD) == 0) 624 vm_object_terminate(object); 625 else 626 VM_OBJECT_UNLOCK(object); 627 object = temp; 628 } 629 } 630 631 /* 632 * vm_object_destroy removes the object from the global object list 633 * and frees the space for the object. 634 */ 635 void 636 vm_object_destroy(vm_object_t object) 637 { 638 639 /* 640 * Remove the object from the global object list. 641 */ 642 mtx_lock(&vm_object_list_mtx); 643 TAILQ_REMOVE(&vm_object_list, object, object_list); 644 mtx_unlock(&vm_object_list_mtx); 645 646 /* 647 * Release the allocation charge. 648 */ 649 if (object->uip != NULL) { 650 KASSERT(object->type == OBJT_DEFAULT || 651 object->type == OBJT_SWAP, 652 ("vm_object_terminate: non-swap obj %p has uip", 653 object)); 654 swap_release_by_uid(object->charge, object->uip); 655 object->charge = 0; 656 uifree(object->uip); 657 object->uip = NULL; 658 } 659 660 /* 661 * Free the space for the object. 662 */ 663 uma_zfree(obj_zone, object); 664 } 665 666 /* 667 * vm_object_terminate actually destroys the specified object, freeing 668 * up all previously used resources. 669 * 670 * The object must be locked. 671 * This routine may block. 672 */ 673 void 674 vm_object_terminate(vm_object_t object) 675 { 676 vm_page_t p; 677 678 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 679 680 /* 681 * Make sure no one uses us. 682 */ 683 vm_object_set_flag(object, OBJ_DEAD); 684 685 /* 686 * wait for the pageout daemon to be done with the object 687 */ 688 vm_object_pip_wait(object, "objtrm"); 689 690 KASSERT(!object->paging_in_progress, 691 ("vm_object_terminate: pageout in progress")); 692 693 /* 694 * Clean and free the pages, as appropriate. All references to the 695 * object are gone, so we don't need to lock it. 696 */ 697 if (object->type == OBJT_VNODE) { 698 struct vnode *vp = (struct vnode *)object->handle; 699 700 /* 701 * Clean pages and flush buffers. 702 */ 703 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 704 VM_OBJECT_UNLOCK(object); 705 706 vinvalbuf(vp, V_SAVE, 0, 0); 707 708 VM_OBJECT_LOCK(object); 709 } 710 711 KASSERT(object->ref_count == 0, 712 ("vm_object_terminate: object with references, ref_count=%d", 713 object->ref_count)); 714 715 /* 716 * Now free any remaining pages. For internal objects, this also 717 * removes them from paging queues. Don't free wired pages, just 718 * remove them from the object. 719 */ 720 vm_page_lock_queues(); 721 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 722 KASSERT(!p->busy && (p->oflags & VPO_BUSY) == 0, 723 ("vm_object_terminate: freeing busy page %p " 724 "p->busy = %d, p->oflags %x\n", p, p->busy, p->oflags)); 725 if (p->wire_count == 0) { 726 vm_page_free(p); 727 cnt.v_pfree++; 728 } else { 729 vm_page_remove(p); 730 } 731 } 732 vm_page_unlock_queues(); 733 734 #if VM_NRESERVLEVEL > 0 735 if (__predict_false(!LIST_EMPTY(&object->rvq))) 736 vm_reserv_break_all(object); 737 #endif 738 if (__predict_false(object->cache != NULL)) 739 vm_page_cache_free(object, 0, 0); 740 741 /* 742 * Let the pager know object is dead. 743 */ 744 vm_pager_deallocate(object); 745 VM_OBJECT_UNLOCK(object); 746 747 vm_object_destroy(object); 748 } 749 750 /* 751 * vm_object_page_clean 752 * 753 * Clean all dirty pages in the specified range of object. Leaves page 754 * on whatever queue it is currently on. If NOSYNC is set then do not 755 * write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC), 756 * leaving the object dirty. 757 * 758 * When stuffing pages asynchronously, allow clustering. XXX we need a 759 * synchronous clustering mode implementation. 760 * 761 * Odd semantics: if start == end, we clean everything. 762 * 763 * The object must be locked. 764 */ 765 void 766 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 767 { 768 vm_page_t p, np; 769 vm_pindex_t tstart, tend; 770 vm_pindex_t pi; 771 int clearobjflags; 772 int pagerflags; 773 int curgeneration; 774 775 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 776 if ((object->flags & OBJ_MIGHTBEDIRTY) == 0) 777 return; 778 KASSERT(object->type == OBJT_VNODE, ("Not a vnode object")); 779 780 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 781 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 782 783 vm_object_set_flag(object, OBJ_CLEANING); 784 785 tstart = start; 786 if (end == 0) { 787 tend = object->size; 788 } else { 789 tend = end; 790 } 791 792 vm_page_lock_queues(); 793 /* 794 * If the caller is smart and only msync()s a range he knows is 795 * dirty, we may be able to avoid an object scan. This results in 796 * a phenominal improvement in performance. We cannot do this 797 * as a matter of course because the object may be huge - e.g. 798 * the size might be in the gigabytes or terrabytes. 799 */ 800 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 801 vm_pindex_t tscan; 802 int scanlimit; 803 int scanreset; 804 805 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 806 if (scanreset < 16) 807 scanreset = 16; 808 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 809 810 scanlimit = scanreset; 811 tscan = tstart; 812 while (tscan < tend) { 813 curgeneration = object->generation; 814 p = vm_page_lookup(object, tscan); 815 if (p == NULL || p->valid == 0) { 816 if (--scanlimit == 0) 817 break; 818 ++tscan; 819 continue; 820 } 821 vm_page_test_dirty(p); 822 if (p->dirty == 0) { 823 if (--scanlimit == 0) 824 break; 825 ++tscan; 826 continue; 827 } 828 /* 829 * If we have been asked to skip nosync pages and 830 * this is a nosync page, we can't continue. 831 */ 832 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 833 if (--scanlimit == 0) 834 break; 835 ++tscan; 836 continue; 837 } 838 scanlimit = scanreset; 839 840 /* 841 * This returns 0 if it was unable to busy the first 842 * page (i.e. had to sleep). 843 */ 844 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 845 } 846 847 /* 848 * If everything was dirty and we flushed it successfully, 849 * and the requested range is not the entire object, we 850 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 851 * return immediately. 852 */ 853 if (tscan >= tend && (tstart || tend < object->size)) { 854 vm_page_unlock_queues(); 855 vm_object_clear_flag(object, OBJ_CLEANING); 856 return; 857 } 858 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 859 } 860 861 /* 862 * Generally set CLEANCHK interlock and make the page read-only so 863 * we can then clear the object flags. 864 * 865 * However, if this is a nosync mmap then the object is likely to 866 * stay dirty so do not mess with the page and do not clear the 867 * object flags. 868 */ 869 clearobjflags = 1; 870 TAILQ_FOREACH(p, &object->memq, listq) { 871 p->oflags |= VPO_CLEANCHK; 872 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) 873 clearobjflags = 0; 874 else 875 pmap_remove_write(p); 876 } 877 878 if (clearobjflags && (tstart == 0) && (tend == object->size)) 879 vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY); 880 881 rescan: 882 curgeneration = object->generation; 883 884 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 885 int n; 886 887 np = TAILQ_NEXT(p, listq); 888 889 again: 890 pi = p->pindex; 891 if ((p->oflags & VPO_CLEANCHK) == 0 || 892 (pi < tstart) || (pi >= tend) || 893 p->valid == 0) { 894 p->oflags &= ~VPO_CLEANCHK; 895 continue; 896 } 897 898 vm_page_test_dirty(p); 899 if (p->dirty == 0) { 900 p->oflags &= ~VPO_CLEANCHK; 901 continue; 902 } 903 904 /* 905 * If we have been asked to skip nosync pages and this is a 906 * nosync page, skip it. Note that the object flags were 907 * not cleared in this case so we do not have to set them. 908 */ 909 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 910 p->oflags &= ~VPO_CLEANCHK; 911 continue; 912 } 913 914 n = vm_object_page_collect_flush(object, p, 915 curgeneration, pagerflags); 916 if (n == 0) 917 goto rescan; 918 919 if (object->generation != curgeneration) 920 goto rescan; 921 922 /* 923 * Try to optimize the next page. If we can't we pick up 924 * our (random) scan where we left off. 925 */ 926 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 927 if ((p = vm_page_lookup(object, pi + n)) != NULL) 928 goto again; 929 } 930 } 931 vm_page_unlock_queues(); 932 #if 0 933 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 934 #endif 935 936 vm_object_clear_flag(object, OBJ_CLEANING); 937 return; 938 } 939 940 static int 941 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 942 { 943 int runlen; 944 int maxf; 945 int chkb; 946 int maxb; 947 int i; 948 vm_pindex_t pi; 949 vm_page_t maf[vm_pageout_page_count]; 950 vm_page_t mab[vm_pageout_page_count]; 951 vm_page_t ma[vm_pageout_page_count]; 952 953 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 954 pi = p->pindex; 955 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 956 vm_page_lock_queues(); 957 if (object->generation != curgeneration) { 958 return(0); 959 } 960 } 961 maxf = 0; 962 for(i = 1; i < vm_pageout_page_count; i++) { 963 vm_page_t tp; 964 965 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 966 if ((tp->oflags & VPO_BUSY) || 967 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 968 (tp->oflags & VPO_CLEANCHK) == 0) || 969 (tp->busy != 0)) 970 break; 971 vm_page_test_dirty(tp); 972 if (tp->dirty == 0) { 973 tp->oflags &= ~VPO_CLEANCHK; 974 break; 975 } 976 maf[ i - 1 ] = tp; 977 maxf++; 978 continue; 979 } 980 break; 981 } 982 983 maxb = 0; 984 chkb = vm_pageout_page_count - maxf; 985 if (chkb) { 986 for(i = 1; i < chkb;i++) { 987 vm_page_t tp; 988 989 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 990 if ((tp->oflags & VPO_BUSY) || 991 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 992 (tp->oflags & VPO_CLEANCHK) == 0) || 993 (tp->busy != 0)) 994 break; 995 vm_page_test_dirty(tp); 996 if (tp->dirty == 0) { 997 tp->oflags &= ~VPO_CLEANCHK; 998 break; 999 } 1000 mab[ i - 1 ] = tp; 1001 maxb++; 1002 continue; 1003 } 1004 break; 1005 } 1006 } 1007 1008 for(i = 0; i < maxb; i++) { 1009 int index = (maxb - i) - 1; 1010 ma[index] = mab[i]; 1011 ma[index]->oflags &= ~VPO_CLEANCHK; 1012 } 1013 p->oflags &= ~VPO_CLEANCHK; 1014 ma[maxb] = p; 1015 for(i = 0; i < maxf; i++) { 1016 int index = (maxb + i) + 1; 1017 ma[index] = maf[i]; 1018 ma[index]->oflags &= ~VPO_CLEANCHK; 1019 } 1020 runlen = maxb + maxf + 1; 1021 1022 vm_pageout_flush(ma, runlen, pagerflags); 1023 for (i = 0; i < runlen; i++) { 1024 if (ma[i]->dirty) { 1025 pmap_remove_write(ma[i]); 1026 ma[i]->oflags |= VPO_CLEANCHK; 1027 1028 /* 1029 * maxf will end up being the actual number of pages 1030 * we wrote out contiguously, non-inclusive of the 1031 * first page. We do not count look-behind pages. 1032 */ 1033 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 1034 maxf = i - maxb - 1; 1035 } 1036 } 1037 return(maxf + 1); 1038 } 1039 1040 /* 1041 * Note that there is absolutely no sense in writing out 1042 * anonymous objects, so we track down the vnode object 1043 * to write out. 1044 * We invalidate (remove) all pages from the address space 1045 * for semantic correctness. 1046 * 1047 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1048 * may start out with a NULL object. 1049 */ 1050 void 1051 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1052 boolean_t syncio, boolean_t invalidate) 1053 { 1054 vm_object_t backing_object; 1055 struct vnode *vp; 1056 struct mount *mp; 1057 int flags; 1058 1059 if (object == NULL) 1060 return; 1061 VM_OBJECT_LOCK(object); 1062 while ((backing_object = object->backing_object) != NULL) { 1063 VM_OBJECT_LOCK(backing_object); 1064 offset += object->backing_object_offset; 1065 VM_OBJECT_UNLOCK(object); 1066 object = backing_object; 1067 if (object->size < OFF_TO_IDX(offset + size)) 1068 size = IDX_TO_OFF(object->size) - offset; 1069 } 1070 /* 1071 * Flush pages if writing is allowed, invalidate them 1072 * if invalidation requested. Pages undergoing I/O 1073 * will be ignored by vm_object_page_remove(). 1074 * 1075 * We cannot lock the vnode and then wait for paging 1076 * to complete without deadlocking against vm_fault. 1077 * Instead we simply call vm_object_page_remove() and 1078 * allow it to block internally on a page-by-page 1079 * basis when it encounters pages undergoing async 1080 * I/O. 1081 */ 1082 if (object->type == OBJT_VNODE && 1083 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1084 int vfslocked; 1085 vp = object->handle; 1086 VM_OBJECT_UNLOCK(object); 1087 (void) vn_start_write(vp, &mp, V_WAIT); 1088 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1089 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1090 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1091 flags |= invalidate ? OBJPC_INVAL : 0; 1092 VM_OBJECT_LOCK(object); 1093 vm_object_page_clean(object, 1094 OFF_TO_IDX(offset), 1095 OFF_TO_IDX(offset + size + PAGE_MASK), 1096 flags); 1097 VM_OBJECT_UNLOCK(object); 1098 VOP_UNLOCK(vp, 0); 1099 VFS_UNLOCK_GIANT(vfslocked); 1100 vn_finished_write(mp); 1101 VM_OBJECT_LOCK(object); 1102 } 1103 if ((object->type == OBJT_VNODE || 1104 object->type == OBJT_DEVICE) && invalidate) { 1105 boolean_t purge; 1106 purge = old_msync || (object->type == OBJT_DEVICE); 1107 vm_object_page_remove(object, 1108 OFF_TO_IDX(offset), 1109 OFF_TO_IDX(offset + size + PAGE_MASK), 1110 purge ? FALSE : TRUE); 1111 } 1112 VM_OBJECT_UNLOCK(object); 1113 } 1114 1115 /* 1116 * vm_object_madvise: 1117 * 1118 * Implements the madvise function at the object/page level. 1119 * 1120 * MADV_WILLNEED (any object) 1121 * 1122 * Activate the specified pages if they are resident. 1123 * 1124 * MADV_DONTNEED (any object) 1125 * 1126 * Deactivate the specified pages if they are resident. 1127 * 1128 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1129 * OBJ_ONEMAPPING only) 1130 * 1131 * Deactivate and clean the specified pages if they are 1132 * resident. This permits the process to reuse the pages 1133 * without faulting or the kernel to reclaim the pages 1134 * without I/O. 1135 */ 1136 void 1137 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1138 { 1139 vm_pindex_t end, tpindex; 1140 vm_object_t backing_object, tobject; 1141 vm_page_t m; 1142 1143 if (object == NULL) 1144 return; 1145 VM_OBJECT_LOCK(object); 1146 end = pindex + count; 1147 /* 1148 * Locate and adjust resident pages 1149 */ 1150 for (; pindex < end; pindex += 1) { 1151 relookup: 1152 tobject = object; 1153 tpindex = pindex; 1154 shadowlookup: 1155 /* 1156 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1157 * and those pages must be OBJ_ONEMAPPING. 1158 */ 1159 if (advise == MADV_FREE) { 1160 if ((tobject->type != OBJT_DEFAULT && 1161 tobject->type != OBJT_SWAP) || 1162 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1163 goto unlock_tobject; 1164 } 1165 } else if (tobject->type == OBJT_PHYS) 1166 goto unlock_tobject; 1167 m = vm_page_lookup(tobject, tpindex); 1168 if (m == NULL && advise == MADV_WILLNEED) { 1169 /* 1170 * If the page is cached, reactivate it. 1171 */ 1172 m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED | 1173 VM_ALLOC_NOBUSY); 1174 } 1175 if (m == NULL) { 1176 /* 1177 * There may be swap even if there is no backing page 1178 */ 1179 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1180 swap_pager_freespace(tobject, tpindex, 1); 1181 /* 1182 * next object 1183 */ 1184 backing_object = tobject->backing_object; 1185 if (backing_object == NULL) 1186 goto unlock_tobject; 1187 VM_OBJECT_LOCK(backing_object); 1188 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1189 if (tobject != object) 1190 VM_OBJECT_UNLOCK(tobject); 1191 tobject = backing_object; 1192 goto shadowlookup; 1193 } else if (m->valid != VM_PAGE_BITS_ALL) 1194 goto unlock_tobject; 1195 /* 1196 * If the page is not in a normal state, skip it. 1197 */ 1198 vm_page_lock_queues(); 1199 if (m->hold_count != 0 || m->wire_count != 0) { 1200 vm_page_unlock_queues(); 1201 goto unlock_tobject; 1202 } 1203 if ((m->oflags & VPO_BUSY) || m->busy) { 1204 if (advise == MADV_WILLNEED) 1205 /* 1206 * Reference the page before unlocking and 1207 * sleeping so that the page daemon is less 1208 * likely to reclaim it. 1209 */ 1210 vm_page_flag_set(m, PG_REFERENCED); 1211 vm_page_unlock_queues(); 1212 if (object != tobject) 1213 VM_OBJECT_UNLOCK(object); 1214 m->oflags |= VPO_WANTED; 1215 msleep(m, VM_OBJECT_MTX(tobject), PDROP | PVM, "madvpo", 1216 0); 1217 VM_OBJECT_LOCK(object); 1218 goto relookup; 1219 } 1220 if (advise == MADV_WILLNEED) { 1221 vm_page_activate(m); 1222 } else if (advise == MADV_DONTNEED) { 1223 vm_page_dontneed(m); 1224 } else if (advise == MADV_FREE) { 1225 /* 1226 * Mark the page clean. This will allow the page 1227 * to be freed up by the system. However, such pages 1228 * are often reused quickly by malloc()/free() 1229 * so we do not do anything that would cause 1230 * a page fault if we can help it. 1231 * 1232 * Specifically, we do not try to actually free 1233 * the page now nor do we try to put it in the 1234 * cache (which would cause a page fault on reuse). 1235 * 1236 * But we do make the page is freeable as we 1237 * can without actually taking the step of unmapping 1238 * it. 1239 */ 1240 pmap_clear_modify(m); 1241 m->dirty = 0; 1242 m->act_count = 0; 1243 vm_page_dontneed(m); 1244 } 1245 vm_page_unlock_queues(); 1246 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1247 swap_pager_freespace(tobject, tpindex, 1); 1248 unlock_tobject: 1249 if (tobject != object) 1250 VM_OBJECT_UNLOCK(tobject); 1251 } 1252 VM_OBJECT_UNLOCK(object); 1253 } 1254 1255 /* 1256 * vm_object_shadow: 1257 * 1258 * Create a new object which is backed by the 1259 * specified existing object range. The source 1260 * object reference is deallocated. 1261 * 1262 * The new object and offset into that object 1263 * are returned in the source parameters. 1264 */ 1265 void 1266 vm_object_shadow( 1267 vm_object_t *object, /* IN/OUT */ 1268 vm_ooffset_t *offset, /* IN/OUT */ 1269 vm_size_t length) 1270 { 1271 vm_object_t source; 1272 vm_object_t result; 1273 1274 source = *object; 1275 1276 /* 1277 * Don't create the new object if the old object isn't shared. 1278 */ 1279 if (source != NULL) { 1280 VM_OBJECT_LOCK(source); 1281 if (source->ref_count == 1 && 1282 source->handle == NULL && 1283 (source->type == OBJT_DEFAULT || 1284 source->type == OBJT_SWAP)) { 1285 VM_OBJECT_UNLOCK(source); 1286 return; 1287 } 1288 VM_OBJECT_UNLOCK(source); 1289 } 1290 1291 /* 1292 * Allocate a new object with the given length. 1293 */ 1294 result = vm_object_allocate(OBJT_DEFAULT, length); 1295 1296 /* 1297 * The new object shadows the source object, adding a reference to it. 1298 * Our caller changes his reference to point to the new object, 1299 * removing a reference to the source object. Net result: no change 1300 * of reference count. 1301 * 1302 * Try to optimize the result object's page color when shadowing 1303 * in order to maintain page coloring consistency in the combined 1304 * shadowed object. 1305 */ 1306 result->backing_object = source; 1307 /* 1308 * Store the offset into the source object, and fix up the offset into 1309 * the new object. 1310 */ 1311 result->backing_object_offset = *offset; 1312 if (source != NULL) { 1313 VM_OBJECT_LOCK(source); 1314 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1315 source->shadow_count++; 1316 source->generation++; 1317 #if VM_NRESERVLEVEL > 0 1318 result->flags |= source->flags & OBJ_COLORED; 1319 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & 1320 ((1 << (VM_NFREEORDER - 1)) - 1); 1321 #endif 1322 VM_OBJECT_UNLOCK(source); 1323 } 1324 1325 1326 /* 1327 * Return the new things 1328 */ 1329 *offset = 0; 1330 *object = result; 1331 } 1332 1333 /* 1334 * vm_object_split: 1335 * 1336 * Split the pages in a map entry into a new object. This affords 1337 * easier removal of unused pages, and keeps object inheritance from 1338 * being a negative impact on memory usage. 1339 */ 1340 void 1341 vm_object_split(vm_map_entry_t entry) 1342 { 1343 vm_page_t m, m_next; 1344 vm_object_t orig_object, new_object, source; 1345 vm_pindex_t idx, offidxstart; 1346 vm_size_t size; 1347 1348 orig_object = entry->object.vm_object; 1349 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1350 return; 1351 if (orig_object->ref_count <= 1) 1352 return; 1353 VM_OBJECT_UNLOCK(orig_object); 1354 1355 offidxstart = OFF_TO_IDX(entry->offset); 1356 size = atop(entry->end - entry->start); 1357 1358 /* 1359 * If swap_pager_copy() is later called, it will convert new_object 1360 * into a swap object. 1361 */ 1362 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1363 1364 /* 1365 * At this point, the new object is still private, so the order in 1366 * which the original and new objects are locked does not matter. 1367 */ 1368 VM_OBJECT_LOCK(new_object); 1369 VM_OBJECT_LOCK(orig_object); 1370 source = orig_object->backing_object; 1371 if (source != NULL) { 1372 VM_OBJECT_LOCK(source); 1373 if ((source->flags & OBJ_DEAD) != 0) { 1374 VM_OBJECT_UNLOCK(source); 1375 VM_OBJECT_UNLOCK(orig_object); 1376 VM_OBJECT_UNLOCK(new_object); 1377 vm_object_deallocate(new_object); 1378 VM_OBJECT_LOCK(orig_object); 1379 return; 1380 } 1381 LIST_INSERT_HEAD(&source->shadow_head, 1382 new_object, shadow_list); 1383 source->shadow_count++; 1384 source->generation++; 1385 vm_object_reference_locked(source); /* for new_object */ 1386 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1387 VM_OBJECT_UNLOCK(source); 1388 new_object->backing_object_offset = 1389 orig_object->backing_object_offset + entry->offset; 1390 new_object->backing_object = source; 1391 } 1392 if (orig_object->uip != NULL) { 1393 new_object->uip = orig_object->uip; 1394 uihold(orig_object->uip); 1395 new_object->charge = ptoa(size); 1396 KASSERT(orig_object->charge >= ptoa(size), 1397 ("orig_object->charge < 0")); 1398 orig_object->charge -= ptoa(size); 1399 } 1400 retry: 1401 if ((m = TAILQ_FIRST(&orig_object->memq)) != NULL) { 1402 if (m->pindex < offidxstart) { 1403 m = vm_page_splay(offidxstart, orig_object->root); 1404 if ((orig_object->root = m)->pindex < offidxstart) 1405 m = TAILQ_NEXT(m, listq); 1406 } 1407 } 1408 vm_page_lock_queues(); 1409 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1410 m = m_next) { 1411 m_next = TAILQ_NEXT(m, listq); 1412 1413 /* 1414 * We must wait for pending I/O to complete before we can 1415 * rename the page. 1416 * 1417 * We do not have to VM_PROT_NONE the page as mappings should 1418 * not be changed by this operation. 1419 */ 1420 if ((m->oflags & VPO_BUSY) || m->busy) { 1421 vm_page_unlock_queues(); 1422 VM_OBJECT_UNLOCK(new_object); 1423 m->oflags |= VPO_WANTED; 1424 msleep(m, VM_OBJECT_MTX(orig_object), PVM, "spltwt", 0); 1425 VM_OBJECT_LOCK(new_object); 1426 goto retry; 1427 } 1428 vm_page_rename(m, new_object, idx); 1429 /* page automatically made dirty by rename and cache handled */ 1430 vm_page_busy(m); 1431 } 1432 vm_page_unlock_queues(); 1433 if (orig_object->type == OBJT_SWAP) { 1434 /* 1435 * swap_pager_copy() can sleep, in which case the orig_object's 1436 * and new_object's locks are released and reacquired. 1437 */ 1438 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1439 1440 /* 1441 * Transfer any cached pages from orig_object to new_object. 1442 */ 1443 if (__predict_false(orig_object->cache != NULL)) 1444 vm_page_cache_transfer(orig_object, offidxstart, 1445 new_object); 1446 } 1447 VM_OBJECT_UNLOCK(orig_object); 1448 TAILQ_FOREACH(m, &new_object->memq, listq) 1449 vm_page_wakeup(m); 1450 VM_OBJECT_UNLOCK(new_object); 1451 entry->object.vm_object = new_object; 1452 entry->offset = 0LL; 1453 vm_object_deallocate(orig_object); 1454 VM_OBJECT_LOCK(new_object); 1455 } 1456 1457 #define OBSC_TEST_ALL_SHADOWED 0x0001 1458 #define OBSC_COLLAPSE_NOWAIT 0x0002 1459 #define OBSC_COLLAPSE_WAIT 0x0004 1460 1461 static int 1462 vm_object_backing_scan(vm_object_t object, int op) 1463 { 1464 int r = 1; 1465 vm_page_t p; 1466 vm_object_t backing_object; 1467 vm_pindex_t backing_offset_index; 1468 1469 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1470 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1471 1472 backing_object = object->backing_object; 1473 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1474 1475 /* 1476 * Initial conditions 1477 */ 1478 if (op & OBSC_TEST_ALL_SHADOWED) { 1479 /* 1480 * We do not want to have to test for the existence of cache 1481 * or swap pages in the backing object. XXX but with the 1482 * new swapper this would be pretty easy to do. 1483 * 1484 * XXX what about anonymous MAP_SHARED memory that hasn't 1485 * been ZFOD faulted yet? If we do not test for this, the 1486 * shadow test may succeed! XXX 1487 */ 1488 if (backing_object->type != OBJT_DEFAULT) { 1489 return (0); 1490 } 1491 } 1492 if (op & OBSC_COLLAPSE_WAIT) { 1493 vm_object_set_flag(backing_object, OBJ_DEAD); 1494 } 1495 1496 /* 1497 * Our scan 1498 */ 1499 p = TAILQ_FIRST(&backing_object->memq); 1500 while (p) { 1501 vm_page_t next = TAILQ_NEXT(p, listq); 1502 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1503 1504 if (op & OBSC_TEST_ALL_SHADOWED) { 1505 vm_page_t pp; 1506 1507 /* 1508 * Ignore pages outside the parent object's range 1509 * and outside the parent object's mapping of the 1510 * backing object. 1511 * 1512 * note that we do not busy the backing object's 1513 * page. 1514 */ 1515 if ( 1516 p->pindex < backing_offset_index || 1517 new_pindex >= object->size 1518 ) { 1519 p = next; 1520 continue; 1521 } 1522 1523 /* 1524 * See if the parent has the page or if the parent's 1525 * object pager has the page. If the parent has the 1526 * page but the page is not valid, the parent's 1527 * object pager must have the page. 1528 * 1529 * If this fails, the parent does not completely shadow 1530 * the object and we might as well give up now. 1531 */ 1532 1533 pp = vm_page_lookup(object, new_pindex); 1534 if ( 1535 (pp == NULL || pp->valid == 0) && 1536 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1537 ) { 1538 r = 0; 1539 break; 1540 } 1541 } 1542 1543 /* 1544 * Check for busy page 1545 */ 1546 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1547 vm_page_t pp; 1548 1549 if (op & OBSC_COLLAPSE_NOWAIT) { 1550 if ((p->oflags & VPO_BUSY) || 1551 !p->valid || 1552 p->busy) { 1553 p = next; 1554 continue; 1555 } 1556 } else if (op & OBSC_COLLAPSE_WAIT) { 1557 if ((p->oflags & VPO_BUSY) || p->busy) { 1558 VM_OBJECT_UNLOCK(object); 1559 p->oflags |= VPO_WANTED; 1560 msleep(p, VM_OBJECT_MTX(backing_object), 1561 PDROP | PVM, "vmocol", 0); 1562 VM_OBJECT_LOCK(object); 1563 VM_OBJECT_LOCK(backing_object); 1564 /* 1565 * If we slept, anything could have 1566 * happened. Since the object is 1567 * marked dead, the backing offset 1568 * should not have changed so we 1569 * just restart our scan. 1570 */ 1571 p = TAILQ_FIRST(&backing_object->memq); 1572 continue; 1573 } 1574 } 1575 1576 KASSERT( 1577 p->object == backing_object, 1578 ("vm_object_backing_scan: object mismatch") 1579 ); 1580 1581 /* 1582 * Destroy any associated swap 1583 */ 1584 if (backing_object->type == OBJT_SWAP) { 1585 swap_pager_freespace( 1586 backing_object, 1587 p->pindex, 1588 1 1589 ); 1590 } 1591 1592 if ( 1593 p->pindex < backing_offset_index || 1594 new_pindex >= object->size 1595 ) { 1596 /* 1597 * Page is out of the parent object's range, we 1598 * can simply destroy it. 1599 */ 1600 vm_page_lock_queues(); 1601 KASSERT(!pmap_page_is_mapped(p), 1602 ("freeing mapped page %p", p)); 1603 if (p->wire_count == 0) 1604 vm_page_free(p); 1605 else 1606 vm_page_remove(p); 1607 vm_page_unlock_queues(); 1608 p = next; 1609 continue; 1610 } 1611 1612 pp = vm_page_lookup(object, new_pindex); 1613 if ( 1614 pp != NULL || 1615 vm_pager_has_page(object, new_pindex, NULL, NULL) 1616 ) { 1617 /* 1618 * page already exists in parent OR swap exists 1619 * for this location in the parent. Destroy 1620 * the original page from the backing object. 1621 * 1622 * Leave the parent's page alone 1623 */ 1624 vm_page_lock_queues(); 1625 KASSERT(!pmap_page_is_mapped(p), 1626 ("freeing mapped page %p", p)); 1627 if (p->wire_count == 0) 1628 vm_page_free(p); 1629 else 1630 vm_page_remove(p); 1631 vm_page_unlock_queues(); 1632 p = next; 1633 continue; 1634 } 1635 1636 #if VM_NRESERVLEVEL > 0 1637 /* 1638 * Rename the reservation. 1639 */ 1640 vm_reserv_rename(p, object, backing_object, 1641 backing_offset_index); 1642 #endif 1643 1644 /* 1645 * Page does not exist in parent, rename the 1646 * page from the backing object to the main object. 1647 * 1648 * If the page was mapped to a process, it can remain 1649 * mapped through the rename. 1650 */ 1651 vm_page_lock_queues(); 1652 vm_page_rename(p, object, new_pindex); 1653 vm_page_unlock_queues(); 1654 /* page automatically made dirty by rename */ 1655 } 1656 p = next; 1657 } 1658 return (r); 1659 } 1660 1661 1662 /* 1663 * this version of collapse allows the operation to occur earlier and 1664 * when paging_in_progress is true for an object... This is not a complete 1665 * operation, but should plug 99.9% of the rest of the leaks. 1666 */ 1667 static void 1668 vm_object_qcollapse(vm_object_t object) 1669 { 1670 vm_object_t backing_object = object->backing_object; 1671 1672 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1673 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1674 1675 if (backing_object->ref_count != 1) 1676 return; 1677 1678 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1679 } 1680 1681 /* 1682 * vm_object_collapse: 1683 * 1684 * Collapse an object with the object backing it. 1685 * Pages in the backing object are moved into the 1686 * parent, and the backing object is deallocated. 1687 */ 1688 void 1689 vm_object_collapse(vm_object_t object) 1690 { 1691 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1692 1693 while (TRUE) { 1694 vm_object_t backing_object; 1695 1696 /* 1697 * Verify that the conditions are right for collapse: 1698 * 1699 * The object exists and the backing object exists. 1700 */ 1701 if ((backing_object = object->backing_object) == NULL) 1702 break; 1703 1704 /* 1705 * we check the backing object first, because it is most likely 1706 * not collapsable. 1707 */ 1708 VM_OBJECT_LOCK(backing_object); 1709 if (backing_object->handle != NULL || 1710 (backing_object->type != OBJT_DEFAULT && 1711 backing_object->type != OBJT_SWAP) || 1712 (backing_object->flags & OBJ_DEAD) || 1713 object->handle != NULL || 1714 (object->type != OBJT_DEFAULT && 1715 object->type != OBJT_SWAP) || 1716 (object->flags & OBJ_DEAD)) { 1717 VM_OBJECT_UNLOCK(backing_object); 1718 break; 1719 } 1720 1721 if ( 1722 object->paging_in_progress != 0 || 1723 backing_object->paging_in_progress != 0 1724 ) { 1725 vm_object_qcollapse(object); 1726 VM_OBJECT_UNLOCK(backing_object); 1727 break; 1728 } 1729 /* 1730 * We know that we can either collapse the backing object (if 1731 * the parent is the only reference to it) or (perhaps) have 1732 * the parent bypass the object if the parent happens to shadow 1733 * all the resident pages in the entire backing object. 1734 * 1735 * This is ignoring pager-backed pages such as swap pages. 1736 * vm_object_backing_scan fails the shadowing test in this 1737 * case. 1738 */ 1739 if (backing_object->ref_count == 1) { 1740 /* 1741 * If there is exactly one reference to the backing 1742 * object, we can collapse it into the parent. 1743 */ 1744 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1745 1746 #if VM_NRESERVLEVEL > 0 1747 /* 1748 * Break any reservations from backing_object. 1749 */ 1750 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1751 vm_reserv_break_all(backing_object); 1752 #endif 1753 1754 /* 1755 * Move the pager from backing_object to object. 1756 */ 1757 if (backing_object->type == OBJT_SWAP) { 1758 /* 1759 * swap_pager_copy() can sleep, in which case 1760 * the backing_object's and object's locks are 1761 * released and reacquired. 1762 */ 1763 swap_pager_copy( 1764 backing_object, 1765 object, 1766 OFF_TO_IDX(object->backing_object_offset), TRUE); 1767 1768 /* 1769 * Free any cached pages from backing_object. 1770 */ 1771 if (__predict_false(backing_object->cache != NULL)) 1772 vm_page_cache_free(backing_object, 0, 0); 1773 } 1774 /* 1775 * Object now shadows whatever backing_object did. 1776 * Note that the reference to 1777 * backing_object->backing_object moves from within 1778 * backing_object to within object. 1779 */ 1780 LIST_REMOVE(object, shadow_list); 1781 backing_object->shadow_count--; 1782 backing_object->generation++; 1783 if (backing_object->backing_object) { 1784 VM_OBJECT_LOCK(backing_object->backing_object); 1785 LIST_REMOVE(backing_object, shadow_list); 1786 LIST_INSERT_HEAD( 1787 &backing_object->backing_object->shadow_head, 1788 object, shadow_list); 1789 /* 1790 * The shadow_count has not changed. 1791 */ 1792 backing_object->backing_object->generation++; 1793 VM_OBJECT_UNLOCK(backing_object->backing_object); 1794 } 1795 object->backing_object = backing_object->backing_object; 1796 object->backing_object_offset += 1797 backing_object->backing_object_offset; 1798 1799 /* 1800 * Discard backing_object. 1801 * 1802 * Since the backing object has no pages, no pager left, 1803 * and no object references within it, all that is 1804 * necessary is to dispose of it. 1805 */ 1806 KASSERT(backing_object->ref_count == 1, ( 1807 "backing_object %p was somehow re-referenced during collapse!", 1808 backing_object)); 1809 VM_OBJECT_UNLOCK(backing_object); 1810 vm_object_destroy(backing_object); 1811 1812 object_collapses++; 1813 } else { 1814 vm_object_t new_backing_object; 1815 1816 /* 1817 * If we do not entirely shadow the backing object, 1818 * there is nothing we can do so we give up. 1819 */ 1820 if (object->resident_page_count != object->size && 1821 vm_object_backing_scan(object, 1822 OBSC_TEST_ALL_SHADOWED) == 0) { 1823 VM_OBJECT_UNLOCK(backing_object); 1824 break; 1825 } 1826 1827 /* 1828 * Make the parent shadow the next object in the 1829 * chain. Deallocating backing_object will not remove 1830 * it, since its reference count is at least 2. 1831 */ 1832 LIST_REMOVE(object, shadow_list); 1833 backing_object->shadow_count--; 1834 backing_object->generation++; 1835 1836 new_backing_object = backing_object->backing_object; 1837 if ((object->backing_object = new_backing_object) != NULL) { 1838 VM_OBJECT_LOCK(new_backing_object); 1839 LIST_INSERT_HEAD( 1840 &new_backing_object->shadow_head, 1841 object, 1842 shadow_list 1843 ); 1844 new_backing_object->shadow_count++; 1845 new_backing_object->generation++; 1846 vm_object_reference_locked(new_backing_object); 1847 VM_OBJECT_UNLOCK(new_backing_object); 1848 object->backing_object_offset += 1849 backing_object->backing_object_offset; 1850 } 1851 1852 /* 1853 * Drop the reference count on backing_object. Since 1854 * its ref_count was at least 2, it will not vanish. 1855 */ 1856 backing_object->ref_count--; 1857 VM_OBJECT_UNLOCK(backing_object); 1858 object_bypasses++; 1859 } 1860 1861 /* 1862 * Try again with this object's new backing object. 1863 */ 1864 } 1865 } 1866 1867 /* 1868 * vm_object_page_remove: 1869 * 1870 * For the given object, either frees or invalidates each of the 1871 * specified pages. In general, a page is freed. However, if a 1872 * page is wired for any reason other than the existence of a 1873 * managed, wired mapping, then it may be invalidated but not 1874 * removed from the object. Pages are specified by the given 1875 * range ["start", "end") and Boolean "clean_only". As a 1876 * special case, if "end" is zero, then the range extends from 1877 * "start" to the end of the object. If "clean_only" is TRUE, 1878 * then only the non-dirty pages within the specified range are 1879 * affected. 1880 * 1881 * In general, this operation should only be performed on objects 1882 * that contain managed pages. There are two exceptions. First, 1883 * it may be performed on the kernel and kmem objects. Second, 1884 * it may be used by msync(..., MS_INVALIDATE) to invalidate 1885 * device-backed pages. 1886 * 1887 * The object must be locked. 1888 */ 1889 void 1890 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1891 boolean_t clean_only) 1892 { 1893 vm_page_t p, next; 1894 int wirings; 1895 1896 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1897 if (object->resident_page_count == 0) 1898 goto skipmemq; 1899 1900 /* 1901 * Since physically-backed objects do not use managed pages, we can't 1902 * remove pages from the object (we must instead remove the page 1903 * references, and then destroy the object). 1904 */ 1905 KASSERT(object->type != OBJT_PHYS || object == kernel_object || 1906 object == kmem_object, 1907 ("attempt to remove pages from a physical object")); 1908 1909 vm_object_pip_add(object, 1); 1910 again: 1911 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1912 if (p->pindex < start) { 1913 p = vm_page_splay(start, object->root); 1914 if ((object->root = p)->pindex < start) 1915 p = TAILQ_NEXT(p, listq); 1916 } 1917 } 1918 vm_page_lock_queues(); 1919 /* 1920 * Assert: the variable p is either (1) the page with the 1921 * least pindex greater than or equal to the parameter pindex 1922 * or (2) NULL. 1923 */ 1924 for (; 1925 p != NULL && (p->pindex < end || end == 0); 1926 p = next) { 1927 next = TAILQ_NEXT(p, listq); 1928 1929 /* 1930 * If the page is wired for any reason besides the 1931 * existence of managed, wired mappings, then it cannot 1932 * be freed. For example, fictitious pages, which 1933 * represent device memory, are inherently wired and 1934 * cannot be freed. They can, however, be invalidated 1935 * if "clean_only" is FALSE. 1936 */ 1937 if ((wirings = p->wire_count) != 0 && 1938 (wirings = pmap_page_wired_mappings(p)) != p->wire_count) { 1939 /* Fictitious pages do not have managed mappings. */ 1940 if ((p->flags & PG_FICTITIOUS) == 0) 1941 pmap_remove_all(p); 1942 /* Account for removal of managed, wired mappings. */ 1943 p->wire_count -= wirings; 1944 if (!clean_only) { 1945 p->valid = 0; 1946 vm_page_undirty(p); 1947 } 1948 continue; 1949 } 1950 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1951 goto again; 1952 KASSERT((p->flags & PG_FICTITIOUS) == 0, 1953 ("vm_object_page_remove: page %p is fictitious", p)); 1954 if (clean_only && p->valid) { 1955 pmap_remove_write(p); 1956 if (p->dirty) 1957 continue; 1958 } 1959 pmap_remove_all(p); 1960 /* Account for removal of managed, wired mappings. */ 1961 if (wirings != 0) 1962 p->wire_count -= wirings; 1963 vm_page_free(p); 1964 } 1965 vm_page_unlock_queues(); 1966 vm_object_pip_wakeup(object); 1967 skipmemq: 1968 if (__predict_false(object->cache != NULL)) 1969 vm_page_cache_free(object, start, end); 1970 } 1971 1972 /* 1973 * Populate the specified range of the object with valid pages. Returns 1974 * TRUE if the range is successfully populated and FALSE otherwise. 1975 * 1976 * Note: This function should be optimized to pass a larger array of 1977 * pages to vm_pager_get_pages() before it is applied to a non- 1978 * OBJT_DEVICE object. 1979 * 1980 * The object must be locked. 1981 */ 1982 boolean_t 1983 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1984 { 1985 vm_page_t m, ma[1]; 1986 vm_pindex_t pindex; 1987 int rv; 1988 1989 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1990 for (pindex = start; pindex < end; pindex++) { 1991 m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL | 1992 VM_ALLOC_RETRY); 1993 if (m->valid != VM_PAGE_BITS_ALL) { 1994 ma[0] = m; 1995 rv = vm_pager_get_pages(object, ma, 1, 0); 1996 m = vm_page_lookup(object, pindex); 1997 if (m == NULL) 1998 break; 1999 if (rv != VM_PAGER_OK) { 2000 vm_page_lock_queues(); 2001 vm_page_free(m); 2002 vm_page_unlock_queues(); 2003 break; 2004 } 2005 } 2006 /* 2007 * Keep "m" busy because a subsequent iteration may unlock 2008 * the object. 2009 */ 2010 } 2011 if (pindex > start) { 2012 m = vm_page_lookup(object, start); 2013 while (m != NULL && m->pindex < pindex) { 2014 vm_page_wakeup(m); 2015 m = TAILQ_NEXT(m, listq); 2016 } 2017 } 2018 return (pindex == end); 2019 } 2020 2021 /* 2022 * Routine: vm_object_coalesce 2023 * Function: Coalesces two objects backing up adjoining 2024 * regions of memory into a single object. 2025 * 2026 * returns TRUE if objects were combined. 2027 * 2028 * NOTE: Only works at the moment if the second object is NULL - 2029 * if it's not, which object do we lock first? 2030 * 2031 * Parameters: 2032 * prev_object First object to coalesce 2033 * prev_offset Offset into prev_object 2034 * prev_size Size of reference to prev_object 2035 * next_size Size of reference to the second object 2036 * reserved Indicator that extension region has 2037 * swap accounted for 2038 * 2039 * Conditions: 2040 * The object must *not* be locked. 2041 */ 2042 boolean_t 2043 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2044 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2045 { 2046 vm_pindex_t next_pindex; 2047 2048 if (prev_object == NULL) 2049 return (TRUE); 2050 VM_OBJECT_LOCK(prev_object); 2051 if (prev_object->type != OBJT_DEFAULT && 2052 prev_object->type != OBJT_SWAP) { 2053 VM_OBJECT_UNLOCK(prev_object); 2054 return (FALSE); 2055 } 2056 2057 /* 2058 * Try to collapse the object first 2059 */ 2060 vm_object_collapse(prev_object); 2061 2062 /* 2063 * Can't coalesce if: . more than one reference . paged out . shadows 2064 * another object . has a copy elsewhere (any of which mean that the 2065 * pages not mapped to prev_entry may be in use anyway) 2066 */ 2067 if (prev_object->backing_object != NULL) { 2068 VM_OBJECT_UNLOCK(prev_object); 2069 return (FALSE); 2070 } 2071 2072 prev_size >>= PAGE_SHIFT; 2073 next_size >>= PAGE_SHIFT; 2074 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2075 2076 if ((prev_object->ref_count > 1) && 2077 (prev_object->size != next_pindex)) { 2078 VM_OBJECT_UNLOCK(prev_object); 2079 return (FALSE); 2080 } 2081 2082 /* 2083 * Account for the charge. 2084 */ 2085 if (prev_object->uip != NULL) { 2086 2087 /* 2088 * If prev_object was charged, then this mapping, 2089 * althought not charged now, may become writable 2090 * later. Non-NULL uip in the object would prevent 2091 * swap reservation during enabling of the write 2092 * access, so reserve swap now. Failed reservation 2093 * cause allocation of the separate object for the map 2094 * entry, and swap reservation for this entry is 2095 * managed in appropriate time. 2096 */ 2097 if (!reserved && !swap_reserve_by_uid(ptoa(next_size), 2098 prev_object->uip)) { 2099 return (FALSE); 2100 } 2101 prev_object->charge += ptoa(next_size); 2102 } 2103 2104 /* 2105 * Remove any pages that may still be in the object from a previous 2106 * deallocation. 2107 */ 2108 if (next_pindex < prev_object->size) { 2109 vm_object_page_remove(prev_object, 2110 next_pindex, 2111 next_pindex + next_size, FALSE); 2112 if (prev_object->type == OBJT_SWAP) 2113 swap_pager_freespace(prev_object, 2114 next_pindex, next_size); 2115 #if 0 2116 if (prev_object->uip != NULL) { 2117 KASSERT(prev_object->charge >= 2118 ptoa(prev_object->size - next_pindex), 2119 ("object %p overcharged 1 %jx %jx", prev_object, 2120 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2121 prev_object->charge -= ptoa(prev_object->size - 2122 next_pindex); 2123 } 2124 #endif 2125 } 2126 2127 /* 2128 * Extend the object if necessary. 2129 */ 2130 if (next_pindex + next_size > prev_object->size) 2131 prev_object->size = next_pindex + next_size; 2132 2133 VM_OBJECT_UNLOCK(prev_object); 2134 return (TRUE); 2135 } 2136 2137 void 2138 vm_object_set_writeable_dirty(vm_object_t object) 2139 { 2140 2141 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2142 if (object->type != OBJT_VNODE || 2143 (object->flags & OBJ_MIGHTBEDIRTY) != 0) 2144 return; 2145 vm_object_set_flag(object, OBJ_MIGHTBEDIRTY); 2146 } 2147 2148 #include "opt_ddb.h" 2149 #ifdef DDB 2150 #include <sys/kernel.h> 2151 2152 #include <sys/cons.h> 2153 2154 #include <ddb/ddb.h> 2155 2156 static int 2157 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2158 { 2159 vm_map_t tmpm; 2160 vm_map_entry_t tmpe; 2161 vm_object_t obj; 2162 int entcount; 2163 2164 if (map == 0) 2165 return 0; 2166 2167 if (entry == 0) { 2168 tmpe = map->header.next; 2169 entcount = map->nentries; 2170 while (entcount-- && (tmpe != &map->header)) { 2171 if (_vm_object_in_map(map, object, tmpe)) { 2172 return 1; 2173 } 2174 tmpe = tmpe->next; 2175 } 2176 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2177 tmpm = entry->object.sub_map; 2178 tmpe = tmpm->header.next; 2179 entcount = tmpm->nentries; 2180 while (entcount-- && tmpe != &tmpm->header) { 2181 if (_vm_object_in_map(tmpm, object, tmpe)) { 2182 return 1; 2183 } 2184 tmpe = tmpe->next; 2185 } 2186 } else if ((obj = entry->object.vm_object) != NULL) { 2187 for (; obj; obj = obj->backing_object) 2188 if (obj == object) { 2189 return 1; 2190 } 2191 } 2192 return 0; 2193 } 2194 2195 static int 2196 vm_object_in_map(vm_object_t object) 2197 { 2198 struct proc *p; 2199 2200 /* sx_slock(&allproc_lock); */ 2201 FOREACH_PROC_IN_SYSTEM(p) { 2202 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2203 continue; 2204 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2205 /* sx_sunlock(&allproc_lock); */ 2206 return 1; 2207 } 2208 } 2209 /* sx_sunlock(&allproc_lock); */ 2210 if (_vm_object_in_map(kernel_map, object, 0)) 2211 return 1; 2212 if (_vm_object_in_map(kmem_map, object, 0)) 2213 return 1; 2214 if (_vm_object_in_map(pager_map, object, 0)) 2215 return 1; 2216 if (_vm_object_in_map(buffer_map, object, 0)) 2217 return 1; 2218 return 0; 2219 } 2220 2221 DB_SHOW_COMMAND(vmochk, vm_object_check) 2222 { 2223 vm_object_t object; 2224 2225 /* 2226 * make sure that internal objs are in a map somewhere 2227 * and none have zero ref counts. 2228 */ 2229 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2230 if (object->handle == NULL && 2231 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2232 if (object->ref_count == 0) { 2233 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2234 (long)object->size); 2235 } 2236 if (!vm_object_in_map(object)) { 2237 db_printf( 2238 "vmochk: internal obj is not in a map: " 2239 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2240 object->ref_count, (u_long)object->size, 2241 (u_long)object->size, 2242 (void *)object->backing_object); 2243 } 2244 } 2245 } 2246 } 2247 2248 /* 2249 * vm_object_print: [ debug ] 2250 */ 2251 DB_SHOW_COMMAND(object, vm_object_print_static) 2252 { 2253 /* XXX convert args. */ 2254 vm_object_t object = (vm_object_t)addr; 2255 boolean_t full = have_addr; 2256 2257 vm_page_t p; 2258 2259 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2260 #define count was_count 2261 2262 int count; 2263 2264 if (object == NULL) 2265 return; 2266 2267 db_iprintf( 2268 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x uip %d charge %jx\n", 2269 object, (int)object->type, (uintmax_t)object->size, 2270 object->resident_page_count, object->ref_count, object->flags, 2271 object->uip ? object->uip->ui_uid : -1, (uintmax_t)object->charge); 2272 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2273 object->shadow_count, 2274 object->backing_object ? object->backing_object->ref_count : 0, 2275 object->backing_object, (uintmax_t)object->backing_object_offset); 2276 2277 if (!full) 2278 return; 2279 2280 db_indent += 2; 2281 count = 0; 2282 TAILQ_FOREACH(p, &object->memq, listq) { 2283 if (count == 0) 2284 db_iprintf("memory:="); 2285 else if (count == 6) { 2286 db_printf("\n"); 2287 db_iprintf(" ..."); 2288 count = 0; 2289 } else 2290 db_printf(","); 2291 count++; 2292 2293 db_printf("(off=0x%jx,page=0x%jx)", 2294 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2295 } 2296 if (count != 0) 2297 db_printf("\n"); 2298 db_indent -= 2; 2299 } 2300 2301 /* XXX. */ 2302 #undef count 2303 2304 /* XXX need this non-static entry for calling from vm_map_print. */ 2305 void 2306 vm_object_print( 2307 /* db_expr_t */ long addr, 2308 boolean_t have_addr, 2309 /* db_expr_t */ long count, 2310 char *modif) 2311 { 2312 vm_object_print_static(addr, have_addr, count, modif); 2313 } 2314 2315 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2316 { 2317 vm_object_t object; 2318 vm_pindex_t fidx; 2319 vm_paddr_t pa; 2320 vm_page_t m, prev_m; 2321 int rcount, nl, c; 2322 2323 nl = 0; 2324 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2325 db_printf("new object: %p\n", (void *)object); 2326 if (nl > 18) { 2327 c = cngetc(); 2328 if (c != ' ') 2329 return; 2330 nl = 0; 2331 } 2332 nl++; 2333 rcount = 0; 2334 fidx = 0; 2335 pa = -1; 2336 TAILQ_FOREACH(m, &object->memq, listq) { 2337 if (m->pindex > 128) 2338 break; 2339 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2340 prev_m->pindex + 1 != m->pindex) { 2341 if (rcount) { 2342 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2343 (long)fidx, rcount, (long)pa); 2344 if (nl > 18) { 2345 c = cngetc(); 2346 if (c != ' ') 2347 return; 2348 nl = 0; 2349 } 2350 nl++; 2351 rcount = 0; 2352 } 2353 } 2354 if (rcount && 2355 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2356 ++rcount; 2357 continue; 2358 } 2359 if (rcount) { 2360 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2361 (long)fidx, rcount, (long)pa); 2362 if (nl > 18) { 2363 c = cngetc(); 2364 if (c != ' ') 2365 return; 2366 nl = 0; 2367 } 2368 nl++; 2369 } 2370 fidx = m->pindex; 2371 pa = VM_PAGE_TO_PHYS(m); 2372 rcount = 1; 2373 } 2374 if (rcount) { 2375 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2376 (long)fidx, rcount, (long)pa); 2377 if (nl > 18) { 2378 c = cngetc(); 2379 if (c != ' ') 2380 return; 2381 nl = 0; 2382 } 2383 nl++; 2384 } 2385 } 2386 } 2387 #endif /* DDB */ 2388