1 /*- 2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * The Mach Operating System project at Carnegie-Mellon University. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 35 * 36 * 37 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 38 * All rights reserved. 39 * 40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 41 * 42 * Permission to use, copy, modify and distribute this software and 43 * its documentation is hereby granted, provided that both the copyright 44 * notice and this permission notice appear in all copies of the 45 * software, derivative works or modified versions, and any portions 46 * thereof, and that both notices appear in supporting documentation. 47 * 48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 51 * 52 * Carnegie Mellon requests users of this software to return to 53 * 54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 55 * School of Computer Science 56 * Carnegie Mellon University 57 * Pittsburgh PA 15213-3890 58 * 59 * any improvements or extensions that they make and grant Carnegie the 60 * rights to redistribute these changes. 61 */ 62 63 /* 64 * Virtual memory object module. 65 */ 66 67 #include <sys/cdefs.h> 68 __FBSDID("$FreeBSD$"); 69 70 #include "opt_vm.h" 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/blockcount.h> 75 #include <sys/cpuset.h> 76 #include <sys/limits.h> 77 #include <sys/lock.h> 78 #include <sys/mman.h> 79 #include <sys/mount.h> 80 #include <sys/kernel.h> 81 #include <sys/pctrie.h> 82 #include <sys/sysctl.h> 83 #include <sys/mutex.h> 84 #include <sys/proc.h> /* for curproc, pageproc */ 85 #include <sys/refcount.h> 86 #include <sys/socket.h> 87 #include <sys/resourcevar.h> 88 #include <sys/refcount.h> 89 #include <sys/rwlock.h> 90 #include <sys/user.h> 91 #include <sys/vnode.h> 92 #include <sys/vmmeter.h> 93 #include <sys/sx.h> 94 95 #include <vm/vm.h> 96 #include <vm/vm_param.h> 97 #include <vm/pmap.h> 98 #include <vm/vm_map.h> 99 #include <vm/vm_object.h> 100 #include <vm/vm_page.h> 101 #include <vm/vm_pageout.h> 102 #include <vm/vm_pager.h> 103 #include <vm/vm_phys.h> 104 #include <vm/vm_pagequeue.h> 105 #include <vm/swap_pager.h> 106 #include <vm/vm_kern.h> 107 #include <vm/vm_extern.h> 108 #include <vm/vm_radix.h> 109 #include <vm/vm_reserv.h> 110 #include <vm/uma.h> 111 112 static int old_msync; 113 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 114 "Use old (insecure) msync behavior"); 115 116 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, 117 int pagerflags, int flags, boolean_t *allclean, 118 boolean_t *eio); 119 static boolean_t vm_object_page_remove_write(vm_page_t p, int flags, 120 boolean_t *allclean); 121 static void vm_object_backing_remove(vm_object_t object); 122 123 /* 124 * Virtual memory objects maintain the actual data 125 * associated with allocated virtual memory. A given 126 * page of memory exists within exactly one object. 127 * 128 * An object is only deallocated when all "references" 129 * are given up. Only one "reference" to a given 130 * region of an object should be writeable. 131 * 132 * Associated with each object is a list of all resident 133 * memory pages belonging to that object; this list is 134 * maintained by the "vm_page" module, and locked by the object's 135 * lock. 136 * 137 * Each object also records a "pager" routine which is 138 * used to retrieve (and store) pages to the proper backing 139 * storage. In addition, objects may be backed by other 140 * objects from which they were virtual-copied. 141 * 142 * The only items within the object structure which are 143 * modified after time of creation are: 144 * reference count locked by object's lock 145 * pager routine locked by object's lock 146 * 147 */ 148 149 struct object_q vm_object_list; 150 struct mtx vm_object_list_mtx; /* lock for object list and count */ 151 152 struct vm_object kernel_object_store; 153 154 static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 155 "VM object stats"); 156 157 static COUNTER_U64_DEFINE_EARLY(object_collapses); 158 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, 159 &object_collapses, 160 "VM object collapses"); 161 162 static COUNTER_U64_DEFINE_EARLY(object_bypasses); 163 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, 164 &object_bypasses, 165 "VM object bypasses"); 166 167 static COUNTER_U64_DEFINE_EARLY(object_collapse_waits); 168 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapse_waits, CTLFLAG_RD, 169 &object_collapse_waits, 170 "Number of sleeps for collapse"); 171 172 static uma_zone_t obj_zone; 173 174 static int vm_object_zinit(void *mem, int size, int flags); 175 176 #ifdef INVARIANTS 177 static void vm_object_zdtor(void *mem, int size, void *arg); 178 179 static void 180 vm_object_zdtor(void *mem, int size, void *arg) 181 { 182 vm_object_t object; 183 184 object = (vm_object_t)mem; 185 KASSERT(object->ref_count == 0, 186 ("object %p ref_count = %d", object, object->ref_count)); 187 KASSERT(TAILQ_EMPTY(&object->memq), 188 ("object %p has resident pages in its memq", object)); 189 KASSERT(vm_radix_is_empty(&object->rtree), 190 ("object %p has resident pages in its trie", object)); 191 #if VM_NRESERVLEVEL > 0 192 KASSERT(LIST_EMPTY(&object->rvq), 193 ("object %p has reservations", 194 object)); 195 #endif 196 KASSERT(!vm_object_busied(object), 197 ("object %p busy = %d", object, blockcount_read(&object->busy))); 198 KASSERT(object->resident_page_count == 0, 199 ("object %p resident_page_count = %d", 200 object, object->resident_page_count)); 201 KASSERT(object->shadow_count == 0, 202 ("object %p shadow_count = %d", 203 object, object->shadow_count)); 204 KASSERT(object->type == OBJT_DEAD, 205 ("object %p has non-dead type %d", 206 object, object->type)); 207 } 208 #endif 209 210 static int 211 vm_object_zinit(void *mem, int size, int flags) 212 { 213 vm_object_t object; 214 215 object = (vm_object_t)mem; 216 rw_init_flags(&object->lock, "vm object", RW_DUPOK | RW_NEW); 217 218 /* These are true for any object that has been freed */ 219 object->type = OBJT_DEAD; 220 vm_radix_init(&object->rtree); 221 refcount_init(&object->ref_count, 0); 222 blockcount_init(&object->paging_in_progress); 223 blockcount_init(&object->busy); 224 object->resident_page_count = 0; 225 object->shadow_count = 0; 226 object->flags = OBJ_DEAD; 227 228 mtx_lock(&vm_object_list_mtx); 229 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 230 mtx_unlock(&vm_object_list_mtx); 231 return (0); 232 } 233 234 static void 235 _vm_object_allocate(objtype_t type, vm_pindex_t size, u_short flags, 236 vm_object_t object, void *handle) 237 { 238 239 TAILQ_INIT(&object->memq); 240 LIST_INIT(&object->shadow_head); 241 242 object->type = type; 243 object->flags = flags; 244 if ((flags & OBJ_SWAP) != 0) 245 pctrie_init(&object->un_pager.swp.swp_blks); 246 247 /* 248 * Ensure that swap_pager_swapoff() iteration over object_list 249 * sees up to date type and pctrie head if it observed 250 * non-dead object. 251 */ 252 atomic_thread_fence_rel(); 253 254 object->pg_color = 0; 255 object->size = size; 256 object->domain.dr_policy = NULL; 257 object->generation = 1; 258 object->cleangeneration = 1; 259 refcount_init(&object->ref_count, 1); 260 object->memattr = VM_MEMATTR_DEFAULT; 261 object->cred = NULL; 262 object->charge = 0; 263 object->handle = handle; 264 object->backing_object = NULL; 265 object->backing_object_offset = (vm_ooffset_t) 0; 266 #if VM_NRESERVLEVEL > 0 267 LIST_INIT(&object->rvq); 268 #endif 269 umtx_shm_object_init(object); 270 } 271 272 /* 273 * vm_object_init: 274 * 275 * Initialize the VM objects module. 276 */ 277 void 278 vm_object_init(void) 279 { 280 TAILQ_INIT(&vm_object_list); 281 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 282 283 rw_init(&kernel_object->lock, "kernel vm object"); 284 _vm_object_allocate(OBJT_PHYS, atop(VM_MAX_KERNEL_ADDRESS - 285 VM_MIN_KERNEL_ADDRESS), OBJ_UNMANAGED, kernel_object, NULL); 286 #if VM_NRESERVLEVEL > 0 287 kernel_object->flags |= OBJ_COLORED; 288 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 289 #endif 290 kernel_object->un_pager.phys.ops = &default_phys_pg_ops; 291 292 /* 293 * The lock portion of struct vm_object must be type stable due 294 * to vm_pageout_fallback_object_lock locking a vm object 295 * without holding any references to it. 296 * 297 * paging_in_progress is valid always. Lockless references to 298 * the objects may acquire pip and then check OBJ_DEAD. 299 */ 300 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 301 #ifdef INVARIANTS 302 vm_object_zdtor, 303 #else 304 NULL, 305 #endif 306 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 307 308 vm_radix_zinit(); 309 } 310 311 void 312 vm_object_clear_flag(vm_object_t object, u_short bits) 313 { 314 315 VM_OBJECT_ASSERT_WLOCKED(object); 316 object->flags &= ~bits; 317 } 318 319 /* 320 * Sets the default memory attribute for the specified object. Pages 321 * that are allocated to this object are by default assigned this memory 322 * attribute. 323 * 324 * Presently, this function must be called before any pages are allocated 325 * to the object. In the future, this requirement may be relaxed for 326 * "default" and "swap" objects. 327 */ 328 int 329 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr) 330 { 331 332 VM_OBJECT_ASSERT_WLOCKED(object); 333 334 if (object->type == OBJT_DEAD) 335 return (KERN_INVALID_ARGUMENT); 336 if (!TAILQ_EMPTY(&object->memq)) 337 return (KERN_FAILURE); 338 339 object->memattr = memattr; 340 return (KERN_SUCCESS); 341 } 342 343 void 344 vm_object_pip_add(vm_object_t object, short i) 345 { 346 347 if (i > 0) 348 blockcount_acquire(&object->paging_in_progress, i); 349 } 350 351 void 352 vm_object_pip_wakeup(vm_object_t object) 353 { 354 355 vm_object_pip_wakeupn(object, 1); 356 } 357 358 void 359 vm_object_pip_wakeupn(vm_object_t object, short i) 360 { 361 362 if (i > 0) 363 blockcount_release(&object->paging_in_progress, i); 364 } 365 366 /* 367 * Atomically drop the object lock and wait for pip to drain. This protects 368 * from sleep/wakeup races due to identity changes. The lock is not re-acquired 369 * on return. 370 */ 371 static void 372 vm_object_pip_sleep(vm_object_t object, const char *waitid) 373 { 374 375 (void)blockcount_sleep(&object->paging_in_progress, &object->lock, 376 waitid, PVM | PDROP); 377 } 378 379 void 380 vm_object_pip_wait(vm_object_t object, const char *waitid) 381 { 382 383 VM_OBJECT_ASSERT_WLOCKED(object); 384 385 blockcount_wait(&object->paging_in_progress, &object->lock, waitid, 386 PVM); 387 } 388 389 void 390 vm_object_pip_wait_unlocked(vm_object_t object, const char *waitid) 391 { 392 393 VM_OBJECT_ASSERT_UNLOCKED(object); 394 395 blockcount_wait(&object->paging_in_progress, NULL, waitid, PVM); 396 } 397 398 /* 399 * vm_object_allocate: 400 * 401 * Returns a new object with the given size. 402 */ 403 vm_object_t 404 vm_object_allocate(objtype_t type, vm_pindex_t size) 405 { 406 vm_object_t object; 407 u_short flags; 408 409 switch (type) { 410 case OBJT_DEAD: 411 panic("vm_object_allocate: can't create OBJT_DEAD"); 412 case OBJT_DEFAULT: 413 flags = OBJ_COLORED; 414 break; 415 case OBJT_SWAP: 416 flags = OBJ_COLORED | OBJ_SWAP; 417 break; 418 case OBJT_DEVICE: 419 case OBJT_SG: 420 flags = OBJ_FICTITIOUS | OBJ_UNMANAGED; 421 break; 422 case OBJT_MGTDEVICE: 423 flags = OBJ_FICTITIOUS; 424 break; 425 case OBJT_PHYS: 426 flags = OBJ_UNMANAGED; 427 break; 428 case OBJT_VNODE: 429 flags = 0; 430 break; 431 default: 432 panic("vm_object_allocate: type %d is undefined or dynamic", 433 type); 434 } 435 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 436 _vm_object_allocate(type, size, flags, object, NULL); 437 438 return (object); 439 } 440 441 vm_object_t 442 vm_object_allocate_dyn(objtype_t dyntype, vm_pindex_t size, u_short flags) 443 { 444 vm_object_t object; 445 446 MPASS(dyntype >= OBJT_FIRST_DYN /* && dyntype < nitems(pagertab) */); 447 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 448 _vm_object_allocate(dyntype, size, flags, object, NULL); 449 450 return (object); 451 } 452 453 /* 454 * vm_object_allocate_anon: 455 * 456 * Returns a new default object of the given size and marked as 457 * anonymous memory for special split/collapse handling. Color 458 * to be initialized by the caller. 459 */ 460 vm_object_t 461 vm_object_allocate_anon(vm_pindex_t size, vm_object_t backing_object, 462 struct ucred *cred, vm_size_t charge) 463 { 464 vm_object_t handle, object; 465 466 if (backing_object == NULL) 467 handle = NULL; 468 else if ((backing_object->flags & OBJ_ANON) != 0) 469 handle = backing_object->handle; 470 else 471 handle = backing_object; 472 object = uma_zalloc(obj_zone, M_WAITOK); 473 _vm_object_allocate(OBJT_DEFAULT, size, OBJ_ANON | OBJ_ONEMAPPING, 474 object, handle); 475 object->cred = cred; 476 object->charge = cred != NULL ? charge : 0; 477 return (object); 478 } 479 480 static void 481 vm_object_reference_vnode(vm_object_t object) 482 { 483 u_int old; 484 485 /* 486 * vnode objects need the lock for the first reference 487 * to serialize with vnode_object_deallocate(). 488 */ 489 if (!refcount_acquire_if_gt(&object->ref_count, 0)) { 490 VM_OBJECT_RLOCK(object); 491 old = refcount_acquire(&object->ref_count); 492 if (object->type == OBJT_VNODE && old == 0) 493 vref(object->handle); 494 VM_OBJECT_RUNLOCK(object); 495 } 496 } 497 498 /* 499 * vm_object_reference: 500 * 501 * Acquires a reference to the given object. 502 */ 503 void 504 vm_object_reference(vm_object_t object) 505 { 506 507 if (object == NULL) 508 return; 509 510 if (object->type == OBJT_VNODE) 511 vm_object_reference_vnode(object); 512 else 513 refcount_acquire(&object->ref_count); 514 KASSERT((object->flags & OBJ_DEAD) == 0, 515 ("vm_object_reference: Referenced dead object.")); 516 } 517 518 /* 519 * vm_object_reference_locked: 520 * 521 * Gets another reference to the given object. 522 * 523 * The object must be locked. 524 */ 525 void 526 vm_object_reference_locked(vm_object_t object) 527 { 528 u_int old; 529 530 VM_OBJECT_ASSERT_LOCKED(object); 531 old = refcount_acquire(&object->ref_count); 532 if (object->type == OBJT_VNODE && old == 0) 533 vref(object->handle); 534 KASSERT((object->flags & OBJ_DEAD) == 0, 535 ("vm_object_reference: Referenced dead object.")); 536 } 537 538 /* 539 * Handle deallocating an object of type OBJT_VNODE. 540 */ 541 static void 542 vm_object_deallocate_vnode(vm_object_t object) 543 { 544 struct vnode *vp = (struct vnode *) object->handle; 545 bool last; 546 547 KASSERT(object->type == OBJT_VNODE, 548 ("vm_object_deallocate_vnode: not a vnode object")); 549 KASSERT(vp != NULL, ("vm_object_deallocate_vnode: missing vp")); 550 551 /* Object lock to protect handle lookup. */ 552 last = refcount_release(&object->ref_count); 553 VM_OBJECT_RUNLOCK(object); 554 555 if (!last) 556 return; 557 558 if (!umtx_shm_vnobj_persistent) 559 umtx_shm_object_terminated(object); 560 561 /* vrele may need the vnode lock. */ 562 vrele(vp); 563 } 564 565 /* 566 * We dropped a reference on an object and discovered that it had a 567 * single remaining shadow. This is a sibling of the reference we 568 * dropped. Attempt to collapse the sibling and backing object. 569 */ 570 static vm_object_t 571 vm_object_deallocate_anon(vm_object_t backing_object) 572 { 573 vm_object_t object; 574 575 /* Fetch the final shadow. */ 576 object = LIST_FIRST(&backing_object->shadow_head); 577 KASSERT(object != NULL && backing_object->shadow_count == 1, 578 ("vm_object_anon_deallocate: ref_count: %d, shadow_count: %d", 579 backing_object->ref_count, backing_object->shadow_count)); 580 KASSERT((object->flags & OBJ_ANON) != 0, 581 ("invalid shadow object %p", object)); 582 583 if (!VM_OBJECT_TRYWLOCK(object)) { 584 /* 585 * Prevent object from disappearing since we do not have a 586 * reference. 587 */ 588 vm_object_pip_add(object, 1); 589 VM_OBJECT_WUNLOCK(backing_object); 590 VM_OBJECT_WLOCK(object); 591 vm_object_pip_wakeup(object); 592 } else 593 VM_OBJECT_WUNLOCK(backing_object); 594 595 /* 596 * Check for a collapse/terminate race with the last reference holder. 597 */ 598 if ((object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) != 0 || 599 !refcount_acquire_if_not_zero(&object->ref_count)) { 600 VM_OBJECT_WUNLOCK(object); 601 return (NULL); 602 } 603 backing_object = object->backing_object; 604 if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0) 605 vm_object_collapse(object); 606 VM_OBJECT_WUNLOCK(object); 607 608 return (object); 609 } 610 611 /* 612 * vm_object_deallocate: 613 * 614 * Release a reference to the specified object, 615 * gained either through a vm_object_allocate 616 * or a vm_object_reference call. When all references 617 * are gone, storage associated with this object 618 * may be relinquished. 619 * 620 * No object may be locked. 621 */ 622 void 623 vm_object_deallocate(vm_object_t object) 624 { 625 vm_object_t temp; 626 bool released; 627 628 while (object != NULL) { 629 /* 630 * If the reference count goes to 0 we start calling 631 * vm_object_terminate() on the object chain. A ref count 632 * of 1 may be a special case depending on the shadow count 633 * being 0 or 1. These cases require a write lock on the 634 * object. 635 */ 636 if ((object->flags & OBJ_ANON) == 0) 637 released = refcount_release_if_gt(&object->ref_count, 1); 638 else 639 released = refcount_release_if_gt(&object->ref_count, 2); 640 if (released) 641 return; 642 643 if (object->type == OBJT_VNODE) { 644 VM_OBJECT_RLOCK(object); 645 if (object->type == OBJT_VNODE) { 646 vm_object_deallocate_vnode(object); 647 return; 648 } 649 VM_OBJECT_RUNLOCK(object); 650 } 651 652 VM_OBJECT_WLOCK(object); 653 KASSERT(object->ref_count > 0, 654 ("vm_object_deallocate: object deallocated too many times: %d", 655 object->type)); 656 657 /* 658 * If this is not the final reference to an anonymous 659 * object we may need to collapse the shadow chain. 660 */ 661 if (!refcount_release(&object->ref_count)) { 662 if (object->ref_count > 1 || 663 object->shadow_count == 0) { 664 if ((object->flags & OBJ_ANON) != 0 && 665 object->ref_count == 1) 666 vm_object_set_flag(object, 667 OBJ_ONEMAPPING); 668 VM_OBJECT_WUNLOCK(object); 669 return; 670 } 671 672 /* Handle collapsing last ref on anonymous objects. */ 673 object = vm_object_deallocate_anon(object); 674 continue; 675 } 676 677 /* 678 * Handle the final reference to an object. We restart 679 * the loop with the backing object to avoid recursion. 680 */ 681 umtx_shm_object_terminated(object); 682 temp = object->backing_object; 683 if (temp != NULL) { 684 KASSERT(object->type == OBJT_DEFAULT || 685 object->type == OBJT_SWAP, 686 ("shadowed tmpfs v_object 2 %p", object)); 687 vm_object_backing_remove(object); 688 } 689 690 KASSERT((object->flags & OBJ_DEAD) == 0, 691 ("vm_object_deallocate: Terminating dead object.")); 692 vm_object_set_flag(object, OBJ_DEAD); 693 vm_object_terminate(object); 694 object = temp; 695 } 696 } 697 698 /* 699 * vm_object_destroy removes the object from the global object list 700 * and frees the space for the object. 701 */ 702 void 703 vm_object_destroy(vm_object_t object) 704 { 705 706 /* 707 * Release the allocation charge. 708 */ 709 if (object->cred != NULL) { 710 swap_release_by_cred(object->charge, object->cred); 711 object->charge = 0; 712 crfree(object->cred); 713 object->cred = NULL; 714 } 715 716 /* 717 * Free the space for the object. 718 */ 719 uma_zfree(obj_zone, object); 720 } 721 722 static void 723 vm_object_backing_remove_locked(vm_object_t object) 724 { 725 vm_object_t backing_object; 726 727 backing_object = object->backing_object; 728 VM_OBJECT_ASSERT_WLOCKED(object); 729 VM_OBJECT_ASSERT_WLOCKED(backing_object); 730 731 KASSERT((object->flags & OBJ_COLLAPSING) == 0, 732 ("vm_object_backing_remove: Removing collapsing object.")); 733 734 if ((object->flags & OBJ_SHADOWLIST) != 0) { 735 LIST_REMOVE(object, shadow_list); 736 backing_object->shadow_count--; 737 object->flags &= ~OBJ_SHADOWLIST; 738 } 739 object->backing_object = NULL; 740 } 741 742 static void 743 vm_object_backing_remove(vm_object_t object) 744 { 745 vm_object_t backing_object; 746 747 VM_OBJECT_ASSERT_WLOCKED(object); 748 749 if ((object->flags & OBJ_SHADOWLIST) != 0) { 750 backing_object = object->backing_object; 751 VM_OBJECT_WLOCK(backing_object); 752 vm_object_backing_remove_locked(object); 753 VM_OBJECT_WUNLOCK(backing_object); 754 } else 755 object->backing_object = NULL; 756 } 757 758 static void 759 vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object) 760 { 761 762 VM_OBJECT_ASSERT_WLOCKED(object); 763 764 if ((backing_object->flags & OBJ_ANON) != 0) { 765 VM_OBJECT_ASSERT_WLOCKED(backing_object); 766 LIST_INSERT_HEAD(&backing_object->shadow_head, object, 767 shadow_list); 768 backing_object->shadow_count++; 769 object->flags |= OBJ_SHADOWLIST; 770 } 771 object->backing_object = backing_object; 772 } 773 774 static void 775 vm_object_backing_insert(vm_object_t object, vm_object_t backing_object) 776 { 777 778 VM_OBJECT_ASSERT_WLOCKED(object); 779 780 if ((backing_object->flags & OBJ_ANON) != 0) { 781 VM_OBJECT_WLOCK(backing_object); 782 vm_object_backing_insert_locked(object, backing_object); 783 VM_OBJECT_WUNLOCK(backing_object); 784 } else 785 object->backing_object = backing_object; 786 } 787 788 /* 789 * Insert an object into a backing_object's shadow list with an additional 790 * reference to the backing_object added. 791 */ 792 static void 793 vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object) 794 { 795 796 VM_OBJECT_ASSERT_WLOCKED(object); 797 798 if ((backing_object->flags & OBJ_ANON) != 0) { 799 VM_OBJECT_WLOCK(backing_object); 800 KASSERT((backing_object->flags & OBJ_DEAD) == 0, 801 ("shadowing dead anonymous object")); 802 vm_object_reference_locked(backing_object); 803 vm_object_backing_insert_locked(object, backing_object); 804 vm_object_clear_flag(backing_object, OBJ_ONEMAPPING); 805 VM_OBJECT_WUNLOCK(backing_object); 806 } else { 807 vm_object_reference(backing_object); 808 object->backing_object = backing_object; 809 } 810 } 811 812 /* 813 * Transfer a backing reference from backing_object to object. 814 */ 815 static void 816 vm_object_backing_transfer(vm_object_t object, vm_object_t backing_object) 817 { 818 vm_object_t new_backing_object; 819 820 /* 821 * Note that the reference to backing_object->backing_object 822 * moves from within backing_object to within object. 823 */ 824 vm_object_backing_remove_locked(object); 825 new_backing_object = backing_object->backing_object; 826 if (new_backing_object == NULL) 827 return; 828 if ((new_backing_object->flags & OBJ_ANON) != 0) { 829 VM_OBJECT_WLOCK(new_backing_object); 830 vm_object_backing_remove_locked(backing_object); 831 vm_object_backing_insert_locked(object, new_backing_object); 832 VM_OBJECT_WUNLOCK(new_backing_object); 833 } else { 834 object->backing_object = new_backing_object; 835 backing_object->backing_object = NULL; 836 } 837 } 838 839 /* 840 * Wait for a concurrent collapse to settle. 841 */ 842 static void 843 vm_object_collapse_wait(vm_object_t object) 844 { 845 846 VM_OBJECT_ASSERT_WLOCKED(object); 847 848 while ((object->flags & OBJ_COLLAPSING) != 0) { 849 vm_object_pip_wait(object, "vmcolwait"); 850 counter_u64_add(object_collapse_waits, 1); 851 } 852 } 853 854 /* 855 * Waits for a backing object to clear a pending collapse and returns 856 * it locked if it is an ANON object. 857 */ 858 static vm_object_t 859 vm_object_backing_collapse_wait(vm_object_t object) 860 { 861 vm_object_t backing_object; 862 863 VM_OBJECT_ASSERT_WLOCKED(object); 864 865 for (;;) { 866 backing_object = object->backing_object; 867 if (backing_object == NULL || 868 (backing_object->flags & OBJ_ANON) == 0) 869 return (NULL); 870 VM_OBJECT_WLOCK(backing_object); 871 if ((backing_object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) == 0) 872 break; 873 VM_OBJECT_WUNLOCK(object); 874 vm_object_pip_sleep(backing_object, "vmbckwait"); 875 counter_u64_add(object_collapse_waits, 1); 876 VM_OBJECT_WLOCK(object); 877 } 878 return (backing_object); 879 } 880 881 /* 882 * vm_object_terminate_pages removes any remaining pageable pages 883 * from the object and resets the object to an empty state. 884 */ 885 static void 886 vm_object_terminate_pages(vm_object_t object) 887 { 888 vm_page_t p, p_next; 889 890 VM_OBJECT_ASSERT_WLOCKED(object); 891 892 /* 893 * Free any remaining pageable pages. This also removes them from the 894 * paging queues. However, don't free wired pages, just remove them 895 * from the object. Rather than incrementally removing each page from 896 * the object, the page and object are reset to any empty state. 897 */ 898 TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) { 899 vm_page_assert_unbusied(p); 900 KASSERT(p->object == object && 901 (p->ref_count & VPRC_OBJREF) != 0, 902 ("vm_object_terminate_pages: page %p is inconsistent", p)); 903 904 p->object = NULL; 905 if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) { 906 VM_CNT_INC(v_pfree); 907 vm_page_free(p); 908 } 909 } 910 911 /* 912 * If the object contained any pages, then reset it to an empty state. 913 * None of the object's fields, including "resident_page_count", were 914 * modified by the preceding loop. 915 */ 916 if (object->resident_page_count != 0) { 917 vm_radix_reclaim_allnodes(&object->rtree); 918 TAILQ_INIT(&object->memq); 919 object->resident_page_count = 0; 920 if (object->type == OBJT_VNODE) 921 vdrop(object->handle); 922 } 923 } 924 925 /* 926 * vm_object_terminate actually destroys the specified object, freeing 927 * up all previously used resources. 928 * 929 * The object must be locked. 930 * This routine may block. 931 */ 932 void 933 vm_object_terminate(vm_object_t object) 934 { 935 936 VM_OBJECT_ASSERT_WLOCKED(object); 937 KASSERT((object->flags & OBJ_DEAD) != 0, 938 ("terminating non-dead obj %p", object)); 939 KASSERT((object->flags & OBJ_COLLAPSING) == 0, 940 ("terminating collapsing obj %p", object)); 941 KASSERT(object->backing_object == NULL, 942 ("terminating shadow obj %p", object)); 943 944 /* 945 * Wait for the pageout daemon and other current users to be 946 * done with the object. Note that new paging_in_progress 947 * users can come after this wait, but they must check 948 * OBJ_DEAD flag set (without unlocking the object), and avoid 949 * the object being terminated. 950 */ 951 vm_object_pip_wait(object, "objtrm"); 952 953 KASSERT(object->ref_count == 0, 954 ("vm_object_terminate: object with references, ref_count=%d", 955 object->ref_count)); 956 957 if ((object->flags & OBJ_PG_DTOR) == 0) 958 vm_object_terminate_pages(object); 959 960 #if VM_NRESERVLEVEL > 0 961 if (__predict_false(!LIST_EMPTY(&object->rvq))) 962 vm_reserv_break_all(object); 963 #endif 964 965 KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT || 966 (object->flags & OBJ_SWAP) != 0, 967 ("%s: non-swap obj %p has cred", __func__, object)); 968 969 /* 970 * Let the pager know object is dead. 971 */ 972 vm_pager_deallocate(object); 973 VM_OBJECT_WUNLOCK(object); 974 975 vm_object_destroy(object); 976 } 977 978 /* 979 * Make the page read-only so that we can clear the object flags. However, if 980 * this is a nosync mmap then the object is likely to stay dirty so do not 981 * mess with the page and do not clear the object flags. Returns TRUE if the 982 * page should be flushed, and FALSE otherwise. 983 */ 984 static boolean_t 985 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean) 986 { 987 988 vm_page_assert_busied(p); 989 990 /* 991 * If we have been asked to skip nosync pages and this is a 992 * nosync page, skip it. Note that the object flags were not 993 * cleared in this case so we do not have to set them. 994 */ 995 if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) { 996 *allclean = FALSE; 997 return (FALSE); 998 } else { 999 pmap_remove_write(p); 1000 return (p->dirty != 0); 1001 } 1002 } 1003 1004 /* 1005 * vm_object_page_clean 1006 * 1007 * Clean all dirty pages in the specified range of object. Leaves page 1008 * on whatever queue it is currently on. If NOSYNC is set then do not 1009 * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC), 1010 * leaving the object dirty. 1011 * 1012 * For swap objects backing tmpfs regular files, do not flush anything, 1013 * but remove write protection on the mapped pages to update mtime through 1014 * mmaped writes. 1015 * 1016 * When stuffing pages asynchronously, allow clustering. XXX we need a 1017 * synchronous clustering mode implementation. 1018 * 1019 * Odd semantics: if start == end, we clean everything. 1020 * 1021 * The object must be locked. 1022 * 1023 * Returns FALSE if some page from the range was not written, as 1024 * reported by the pager, and TRUE otherwise. 1025 */ 1026 boolean_t 1027 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end, 1028 int flags) 1029 { 1030 vm_page_t np, p; 1031 vm_pindex_t pi, tend, tstart; 1032 int curgeneration, n, pagerflags; 1033 boolean_t eio, res, allclean; 1034 1035 VM_OBJECT_ASSERT_WLOCKED(object); 1036 1037 if (!vm_object_mightbedirty(object) || object->resident_page_count == 0) 1038 return (TRUE); 1039 1040 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ? 1041 VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 1042 pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0; 1043 1044 tstart = OFF_TO_IDX(start); 1045 tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK); 1046 allclean = tstart == 0 && tend >= object->size; 1047 res = TRUE; 1048 1049 rescan: 1050 curgeneration = object->generation; 1051 1052 for (p = vm_page_find_least(object, tstart); p != NULL; p = np) { 1053 pi = p->pindex; 1054 if (pi >= tend) 1055 break; 1056 np = TAILQ_NEXT(p, listq); 1057 if (vm_page_none_valid(p)) 1058 continue; 1059 if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) { 1060 if (object->generation != curgeneration && 1061 (flags & OBJPC_SYNC) != 0) 1062 goto rescan; 1063 np = vm_page_find_least(object, pi); 1064 continue; 1065 } 1066 if (!vm_object_page_remove_write(p, flags, &allclean)) { 1067 vm_page_xunbusy(p); 1068 continue; 1069 } 1070 if (object->type == OBJT_VNODE) { 1071 n = vm_object_page_collect_flush(object, p, pagerflags, 1072 flags, &allclean, &eio); 1073 if (eio) { 1074 res = FALSE; 1075 allclean = FALSE; 1076 } 1077 if (object->generation != curgeneration && 1078 (flags & OBJPC_SYNC) != 0) 1079 goto rescan; 1080 1081 /* 1082 * If the VOP_PUTPAGES() did a truncated write, so 1083 * that even the first page of the run is not fully 1084 * written, vm_pageout_flush() returns 0 as the run 1085 * length. Since the condition that caused truncated 1086 * write may be permanent, e.g. exhausted free space, 1087 * accepting n == 0 would cause an infinite loop. 1088 * 1089 * Forwarding the iterator leaves the unwritten page 1090 * behind, but there is not much we can do there if 1091 * filesystem refuses to write it. 1092 */ 1093 if (n == 0) { 1094 n = 1; 1095 allclean = FALSE; 1096 } 1097 } else { 1098 n = 1; 1099 vm_page_xunbusy(p); 1100 } 1101 np = vm_page_find_least(object, pi + n); 1102 } 1103 #if 0 1104 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0); 1105 #endif 1106 1107 /* 1108 * Leave updating cleangeneration for tmpfs objects to tmpfs 1109 * scan. It needs to update mtime, which happens for other 1110 * filesystems during page writeouts. 1111 */ 1112 if (allclean && object->type == OBJT_VNODE) 1113 object->cleangeneration = curgeneration; 1114 return (res); 1115 } 1116 1117 static int 1118 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, 1119 int flags, boolean_t *allclean, boolean_t *eio) 1120 { 1121 vm_page_t ma[vm_pageout_page_count], p_first, tp; 1122 int count, i, mreq, runlen; 1123 1124 vm_page_lock_assert(p, MA_NOTOWNED); 1125 vm_page_assert_xbusied(p); 1126 VM_OBJECT_ASSERT_WLOCKED(object); 1127 1128 count = 1; 1129 mreq = 0; 1130 1131 for (tp = p; count < vm_pageout_page_count; count++) { 1132 tp = vm_page_next(tp); 1133 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1134 break; 1135 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1136 vm_page_xunbusy(tp); 1137 break; 1138 } 1139 } 1140 1141 for (p_first = p; count < vm_pageout_page_count; count++) { 1142 tp = vm_page_prev(p_first); 1143 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1144 break; 1145 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1146 vm_page_xunbusy(tp); 1147 break; 1148 } 1149 p_first = tp; 1150 mreq++; 1151 } 1152 1153 for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++) 1154 ma[i] = tp; 1155 1156 vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio); 1157 return (runlen); 1158 } 1159 1160 /* 1161 * Note that there is absolutely no sense in writing out 1162 * anonymous objects, so we track down the vnode object 1163 * to write out. 1164 * We invalidate (remove) all pages from the address space 1165 * for semantic correctness. 1166 * 1167 * If the backing object is a device object with unmanaged pages, then any 1168 * mappings to the specified range of pages must be removed before this 1169 * function is called. 1170 * 1171 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1172 * may start out with a NULL object. 1173 */ 1174 boolean_t 1175 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1176 boolean_t syncio, boolean_t invalidate) 1177 { 1178 vm_object_t backing_object; 1179 struct vnode *vp; 1180 struct mount *mp; 1181 int error, flags, fsync_after; 1182 boolean_t res; 1183 1184 if (object == NULL) 1185 return (TRUE); 1186 res = TRUE; 1187 error = 0; 1188 VM_OBJECT_WLOCK(object); 1189 while ((backing_object = object->backing_object) != NULL) { 1190 VM_OBJECT_WLOCK(backing_object); 1191 offset += object->backing_object_offset; 1192 VM_OBJECT_WUNLOCK(object); 1193 object = backing_object; 1194 if (object->size < OFF_TO_IDX(offset + size)) 1195 size = IDX_TO_OFF(object->size) - offset; 1196 } 1197 /* 1198 * Flush pages if writing is allowed, invalidate them 1199 * if invalidation requested. Pages undergoing I/O 1200 * will be ignored by vm_object_page_remove(). 1201 * 1202 * We cannot lock the vnode and then wait for paging 1203 * to complete without deadlocking against vm_fault. 1204 * Instead we simply call vm_object_page_remove() and 1205 * allow it to block internally on a page-by-page 1206 * basis when it encounters pages undergoing async 1207 * I/O. 1208 */ 1209 if (object->type == OBJT_VNODE && 1210 vm_object_mightbedirty(object) != 0 && 1211 ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) { 1212 VM_OBJECT_WUNLOCK(object); 1213 (void) vn_start_write(vp, &mp, V_WAIT); 1214 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1215 if (syncio && !invalidate && offset == 0 && 1216 atop(size) == object->size) { 1217 /* 1218 * If syncing the whole mapping of the file, 1219 * it is faster to schedule all the writes in 1220 * async mode, also allowing the clustering, 1221 * and then wait for i/o to complete. 1222 */ 1223 flags = 0; 1224 fsync_after = TRUE; 1225 } else { 1226 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1227 flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0; 1228 fsync_after = FALSE; 1229 } 1230 VM_OBJECT_WLOCK(object); 1231 res = vm_object_page_clean(object, offset, offset + size, 1232 flags); 1233 VM_OBJECT_WUNLOCK(object); 1234 if (fsync_after) 1235 error = VOP_FSYNC(vp, MNT_WAIT, curthread); 1236 VOP_UNLOCK(vp); 1237 vn_finished_write(mp); 1238 if (error != 0) 1239 res = FALSE; 1240 VM_OBJECT_WLOCK(object); 1241 } 1242 if ((object->type == OBJT_VNODE || 1243 object->type == OBJT_DEVICE) && invalidate) { 1244 if (object->type == OBJT_DEVICE) 1245 /* 1246 * The option OBJPR_NOTMAPPED must be passed here 1247 * because vm_object_page_remove() cannot remove 1248 * unmanaged mappings. 1249 */ 1250 flags = OBJPR_NOTMAPPED; 1251 else if (old_msync) 1252 flags = 0; 1253 else 1254 flags = OBJPR_CLEANONLY; 1255 vm_object_page_remove(object, OFF_TO_IDX(offset), 1256 OFF_TO_IDX(offset + size + PAGE_MASK), flags); 1257 } 1258 VM_OBJECT_WUNLOCK(object); 1259 return (res); 1260 } 1261 1262 /* 1263 * Determine whether the given advice can be applied to the object. Advice is 1264 * not applied to unmanaged pages since they never belong to page queues, and 1265 * since MADV_FREE is destructive, it can apply only to anonymous pages that 1266 * have been mapped at most once. 1267 */ 1268 static bool 1269 vm_object_advice_applies(vm_object_t object, int advice) 1270 { 1271 1272 if ((object->flags & OBJ_UNMANAGED) != 0) 1273 return (false); 1274 if (advice != MADV_FREE) 1275 return (true); 1276 return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) == 1277 (OBJ_ONEMAPPING | OBJ_ANON)); 1278 } 1279 1280 static void 1281 vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex, 1282 vm_size_t size) 1283 { 1284 1285 if (advice == MADV_FREE) 1286 vm_pager_freespace(object, pindex, size); 1287 } 1288 1289 /* 1290 * vm_object_madvise: 1291 * 1292 * Implements the madvise function at the object/page level. 1293 * 1294 * MADV_WILLNEED (any object) 1295 * 1296 * Activate the specified pages if they are resident. 1297 * 1298 * MADV_DONTNEED (any object) 1299 * 1300 * Deactivate the specified pages if they are resident. 1301 * 1302 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1303 * OBJ_ONEMAPPING only) 1304 * 1305 * Deactivate and clean the specified pages if they are 1306 * resident. This permits the process to reuse the pages 1307 * without faulting or the kernel to reclaim the pages 1308 * without I/O. 1309 */ 1310 void 1311 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end, 1312 int advice) 1313 { 1314 vm_pindex_t tpindex; 1315 vm_object_t backing_object, tobject; 1316 vm_page_t m, tm; 1317 1318 if (object == NULL) 1319 return; 1320 1321 relookup: 1322 VM_OBJECT_WLOCK(object); 1323 if (!vm_object_advice_applies(object, advice)) { 1324 VM_OBJECT_WUNLOCK(object); 1325 return; 1326 } 1327 for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) { 1328 tobject = object; 1329 1330 /* 1331 * If the next page isn't resident in the top-level object, we 1332 * need to search the shadow chain. When applying MADV_FREE, we 1333 * take care to release any swap space used to store 1334 * non-resident pages. 1335 */ 1336 if (m == NULL || pindex < m->pindex) { 1337 /* 1338 * Optimize a common case: if the top-level object has 1339 * no backing object, we can skip over the non-resident 1340 * range in constant time. 1341 */ 1342 if (object->backing_object == NULL) { 1343 tpindex = (m != NULL && m->pindex < end) ? 1344 m->pindex : end; 1345 vm_object_madvise_freespace(object, advice, 1346 pindex, tpindex - pindex); 1347 if ((pindex = tpindex) == end) 1348 break; 1349 goto next_page; 1350 } 1351 1352 tpindex = pindex; 1353 do { 1354 vm_object_madvise_freespace(tobject, advice, 1355 tpindex, 1); 1356 /* 1357 * Prepare to search the next object in the 1358 * chain. 1359 */ 1360 backing_object = tobject->backing_object; 1361 if (backing_object == NULL) 1362 goto next_pindex; 1363 VM_OBJECT_WLOCK(backing_object); 1364 tpindex += 1365 OFF_TO_IDX(tobject->backing_object_offset); 1366 if (tobject != object) 1367 VM_OBJECT_WUNLOCK(tobject); 1368 tobject = backing_object; 1369 if (!vm_object_advice_applies(tobject, advice)) 1370 goto next_pindex; 1371 } while ((tm = vm_page_lookup(tobject, tpindex)) == 1372 NULL); 1373 } else { 1374 next_page: 1375 tm = m; 1376 m = TAILQ_NEXT(m, listq); 1377 } 1378 1379 /* 1380 * If the page is not in a normal state, skip it. The page 1381 * can not be invalidated while the object lock is held. 1382 */ 1383 if (!vm_page_all_valid(tm) || vm_page_wired(tm)) 1384 goto next_pindex; 1385 KASSERT((tm->flags & PG_FICTITIOUS) == 0, 1386 ("vm_object_madvise: page %p is fictitious", tm)); 1387 KASSERT((tm->oflags & VPO_UNMANAGED) == 0, 1388 ("vm_object_madvise: page %p is not managed", tm)); 1389 if (vm_page_tryxbusy(tm) == 0) { 1390 if (object != tobject) 1391 VM_OBJECT_WUNLOCK(object); 1392 if (advice == MADV_WILLNEED) { 1393 /* 1394 * Reference the page before unlocking and 1395 * sleeping so that the page daemon is less 1396 * likely to reclaim it. 1397 */ 1398 vm_page_aflag_set(tm, PGA_REFERENCED); 1399 } 1400 if (!vm_page_busy_sleep(tm, "madvpo", 0)) 1401 VM_OBJECT_WUNLOCK(tobject); 1402 goto relookup; 1403 } 1404 vm_page_advise(tm, advice); 1405 vm_page_xunbusy(tm); 1406 vm_object_madvise_freespace(tobject, advice, tm->pindex, 1); 1407 next_pindex: 1408 if (tobject != object) 1409 VM_OBJECT_WUNLOCK(tobject); 1410 } 1411 VM_OBJECT_WUNLOCK(object); 1412 } 1413 1414 /* 1415 * vm_object_shadow: 1416 * 1417 * Create a new object which is backed by the 1418 * specified existing object range. The source 1419 * object reference is deallocated. 1420 * 1421 * The new object and offset into that object 1422 * are returned in the source parameters. 1423 */ 1424 void 1425 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length, 1426 struct ucred *cred, bool shared) 1427 { 1428 vm_object_t source; 1429 vm_object_t result; 1430 1431 source = *object; 1432 1433 /* 1434 * Don't create the new object if the old object isn't shared. 1435 * 1436 * If we hold the only reference we can guarantee that it won't 1437 * increase while we have the map locked. Otherwise the race is 1438 * harmless and we will end up with an extra shadow object that 1439 * will be collapsed later. 1440 */ 1441 if (source != NULL && source->ref_count == 1 && 1442 (source->flags & OBJ_ANON) != 0) 1443 return; 1444 1445 /* 1446 * Allocate a new object with the given length. 1447 */ 1448 result = vm_object_allocate_anon(atop(length), source, cred, length); 1449 1450 /* 1451 * Store the offset into the source object, and fix up the offset into 1452 * the new object. 1453 */ 1454 result->backing_object_offset = *offset; 1455 1456 if (shared || source != NULL) { 1457 VM_OBJECT_WLOCK(result); 1458 1459 /* 1460 * The new object shadows the source object, adding a 1461 * reference to it. Our caller changes his reference 1462 * to point to the new object, removing a reference to 1463 * the source object. Net result: no change of 1464 * reference count, unless the caller needs to add one 1465 * more reference due to forking a shared map entry. 1466 */ 1467 if (shared) { 1468 vm_object_reference_locked(result); 1469 vm_object_clear_flag(result, OBJ_ONEMAPPING); 1470 } 1471 1472 /* 1473 * Try to optimize the result object's page color when 1474 * shadowing in order to maintain page coloring 1475 * consistency in the combined shadowed object. 1476 */ 1477 if (source != NULL) { 1478 vm_object_backing_insert(result, source); 1479 result->domain = source->domain; 1480 #if VM_NRESERVLEVEL > 0 1481 result->flags |= source->flags & OBJ_COLORED; 1482 result->pg_color = (source->pg_color + 1483 OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER - 1484 1)) - 1); 1485 #endif 1486 } 1487 VM_OBJECT_WUNLOCK(result); 1488 } 1489 1490 /* 1491 * Return the new things 1492 */ 1493 *offset = 0; 1494 *object = result; 1495 } 1496 1497 /* 1498 * vm_object_split: 1499 * 1500 * Split the pages in a map entry into a new object. This affords 1501 * easier removal of unused pages, and keeps object inheritance from 1502 * being a negative impact on memory usage. 1503 */ 1504 void 1505 vm_object_split(vm_map_entry_t entry) 1506 { 1507 vm_page_t m, m_busy, m_next; 1508 vm_object_t orig_object, new_object, backing_object; 1509 vm_pindex_t idx, offidxstart; 1510 vm_size_t size; 1511 1512 orig_object = entry->object.vm_object; 1513 KASSERT((orig_object->flags & OBJ_ONEMAPPING) != 0, 1514 ("vm_object_split: Splitting object with multiple mappings.")); 1515 if ((orig_object->flags & OBJ_ANON) == 0) 1516 return; 1517 if (orig_object->ref_count <= 1) 1518 return; 1519 VM_OBJECT_WUNLOCK(orig_object); 1520 1521 offidxstart = OFF_TO_IDX(entry->offset); 1522 size = atop(entry->end - entry->start); 1523 1524 /* 1525 * If swap_pager_copy() is later called, it will convert new_object 1526 * into a swap object. 1527 */ 1528 new_object = vm_object_allocate_anon(size, orig_object, 1529 orig_object->cred, ptoa(size)); 1530 1531 /* 1532 * We must wait for the orig_object to complete any in-progress 1533 * collapse so that the swap blocks are stable below. The 1534 * additional reference on backing_object by new object will 1535 * prevent further collapse operations until split completes. 1536 */ 1537 VM_OBJECT_WLOCK(orig_object); 1538 vm_object_collapse_wait(orig_object); 1539 1540 /* 1541 * At this point, the new object is still private, so the order in 1542 * which the original and new objects are locked does not matter. 1543 */ 1544 VM_OBJECT_WLOCK(new_object); 1545 new_object->domain = orig_object->domain; 1546 backing_object = orig_object->backing_object; 1547 if (backing_object != NULL) { 1548 vm_object_backing_insert_ref(new_object, backing_object); 1549 new_object->backing_object_offset = 1550 orig_object->backing_object_offset + entry->offset; 1551 } 1552 if (orig_object->cred != NULL) { 1553 crhold(orig_object->cred); 1554 KASSERT(orig_object->charge >= ptoa(size), 1555 ("orig_object->charge < 0")); 1556 orig_object->charge -= ptoa(size); 1557 } 1558 1559 /* 1560 * Mark the split operation so that swap_pager_getpages() knows 1561 * that the object is in transition. 1562 */ 1563 vm_object_set_flag(orig_object, OBJ_SPLIT); 1564 m_busy = NULL; 1565 #ifdef INVARIANTS 1566 idx = 0; 1567 #endif 1568 retry: 1569 m = vm_page_find_least(orig_object, offidxstart); 1570 KASSERT(m == NULL || idx <= m->pindex - offidxstart, 1571 ("%s: object %p was repopulated", __func__, orig_object)); 1572 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1573 m = m_next) { 1574 m_next = TAILQ_NEXT(m, listq); 1575 1576 /* 1577 * We must wait for pending I/O to complete before we can 1578 * rename the page. 1579 * 1580 * We do not have to VM_PROT_NONE the page as mappings should 1581 * not be changed by this operation. 1582 */ 1583 if (vm_page_tryxbusy(m) == 0) { 1584 VM_OBJECT_WUNLOCK(new_object); 1585 if (vm_page_busy_sleep(m, "spltwt", 0)) 1586 VM_OBJECT_WLOCK(orig_object); 1587 VM_OBJECT_WLOCK(new_object); 1588 goto retry; 1589 } 1590 1591 /* 1592 * The page was left invalid. Likely placed there by 1593 * an incomplete fault. Just remove and ignore. 1594 */ 1595 if (vm_page_none_valid(m)) { 1596 if (vm_page_remove(m)) 1597 vm_page_free(m); 1598 continue; 1599 } 1600 1601 /* vm_page_rename() will dirty the page. */ 1602 if (vm_page_rename(m, new_object, idx)) { 1603 vm_page_xunbusy(m); 1604 VM_OBJECT_WUNLOCK(new_object); 1605 VM_OBJECT_WUNLOCK(orig_object); 1606 vm_radix_wait(); 1607 VM_OBJECT_WLOCK(orig_object); 1608 VM_OBJECT_WLOCK(new_object); 1609 goto retry; 1610 } 1611 1612 #if VM_NRESERVLEVEL > 0 1613 /* 1614 * If some of the reservation's allocated pages remain with 1615 * the original object, then transferring the reservation to 1616 * the new object is neither particularly beneficial nor 1617 * particularly harmful as compared to leaving the reservation 1618 * with the original object. If, however, all of the 1619 * reservation's allocated pages are transferred to the new 1620 * object, then transferring the reservation is typically 1621 * beneficial. Determining which of these two cases applies 1622 * would be more costly than unconditionally renaming the 1623 * reservation. 1624 */ 1625 vm_reserv_rename(m, new_object, orig_object, offidxstart); 1626 #endif 1627 1628 /* 1629 * orig_object's type may change while sleeping, so keep track 1630 * of the beginning of the busied range. 1631 */ 1632 if (orig_object->type != OBJT_SWAP) 1633 vm_page_xunbusy(m); 1634 else if (m_busy == NULL) 1635 m_busy = m; 1636 } 1637 if ((orig_object->flags & OBJ_SWAP) != 0) { 1638 /* 1639 * swap_pager_copy() can sleep, in which case the orig_object's 1640 * and new_object's locks are released and reacquired. 1641 */ 1642 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1643 if (m_busy != NULL) 1644 TAILQ_FOREACH_FROM(m_busy, &new_object->memq, listq) 1645 vm_page_xunbusy(m_busy); 1646 } 1647 vm_object_clear_flag(orig_object, OBJ_SPLIT); 1648 VM_OBJECT_WUNLOCK(orig_object); 1649 VM_OBJECT_WUNLOCK(new_object); 1650 entry->object.vm_object = new_object; 1651 entry->offset = 0LL; 1652 vm_object_deallocate(orig_object); 1653 VM_OBJECT_WLOCK(new_object); 1654 } 1655 1656 static vm_page_t 1657 vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p) 1658 { 1659 vm_object_t backing_object; 1660 1661 VM_OBJECT_ASSERT_WLOCKED(object); 1662 backing_object = object->backing_object; 1663 VM_OBJECT_ASSERT_WLOCKED(backing_object); 1664 1665 KASSERT(p == NULL || p->object == object || p->object == backing_object, 1666 ("invalid ownership %p %p %p", p, object, backing_object)); 1667 /* The page is only NULL when rename fails. */ 1668 if (p == NULL) { 1669 VM_OBJECT_WUNLOCK(object); 1670 VM_OBJECT_WUNLOCK(backing_object); 1671 vm_radix_wait(); 1672 VM_OBJECT_WLOCK(object); 1673 } else if (p->object == object) { 1674 VM_OBJECT_WUNLOCK(backing_object); 1675 if (vm_page_busy_sleep(p, "vmocol", 0)) 1676 VM_OBJECT_WLOCK(object); 1677 } else { 1678 VM_OBJECT_WUNLOCK(object); 1679 if (!vm_page_busy_sleep(p, "vmocol", 0)) 1680 VM_OBJECT_WUNLOCK(backing_object); 1681 VM_OBJECT_WLOCK(object); 1682 } 1683 VM_OBJECT_WLOCK(backing_object); 1684 return (TAILQ_FIRST(&backing_object->memq)); 1685 } 1686 1687 static bool 1688 vm_object_scan_all_shadowed(vm_object_t object) 1689 { 1690 vm_object_t backing_object; 1691 vm_page_t p, pp; 1692 vm_pindex_t backing_offset_index, new_pindex, pi, ps; 1693 1694 VM_OBJECT_ASSERT_WLOCKED(object); 1695 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1696 1697 backing_object = object->backing_object; 1698 1699 if ((backing_object->flags & OBJ_ANON) == 0) 1700 return (false); 1701 1702 pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1703 p = vm_page_find_least(backing_object, pi); 1704 ps = swap_pager_find_least(backing_object, pi); 1705 1706 /* 1707 * Only check pages inside the parent object's range and 1708 * inside the parent object's mapping of the backing object. 1709 */ 1710 for (;; pi++) { 1711 if (p != NULL && p->pindex < pi) 1712 p = TAILQ_NEXT(p, listq); 1713 if (ps < pi) 1714 ps = swap_pager_find_least(backing_object, pi); 1715 if (p == NULL && ps >= backing_object->size) 1716 break; 1717 else if (p == NULL) 1718 pi = ps; 1719 else 1720 pi = MIN(p->pindex, ps); 1721 1722 new_pindex = pi - backing_offset_index; 1723 if (new_pindex >= object->size) 1724 break; 1725 1726 if (p != NULL) { 1727 /* 1728 * If the backing object page is busy a 1729 * grandparent or older page may still be 1730 * undergoing CoW. It is not safe to collapse 1731 * the backing object until it is quiesced. 1732 */ 1733 if (vm_page_tryxbusy(p) == 0) 1734 return (false); 1735 1736 /* 1737 * We raced with the fault handler that left 1738 * newly allocated invalid page on the object 1739 * queue and retried. 1740 */ 1741 if (!vm_page_all_valid(p)) 1742 goto unbusy_ret; 1743 } 1744 1745 /* 1746 * See if the parent has the page or if the parent's object 1747 * pager has the page. If the parent has the page but the page 1748 * is not valid, the parent's object pager must have the page. 1749 * 1750 * If this fails, the parent does not completely shadow the 1751 * object and we might as well give up now. 1752 */ 1753 pp = vm_page_lookup(object, new_pindex); 1754 1755 /* 1756 * The valid check here is stable due to object lock 1757 * being required to clear valid and initiate paging. 1758 * Busy of p disallows fault handler to validate pp. 1759 */ 1760 if ((pp == NULL || vm_page_none_valid(pp)) && 1761 !vm_pager_has_page(object, new_pindex, NULL, NULL)) 1762 goto unbusy_ret; 1763 if (p != NULL) 1764 vm_page_xunbusy(p); 1765 } 1766 return (true); 1767 1768 unbusy_ret: 1769 if (p != NULL) 1770 vm_page_xunbusy(p); 1771 return (false); 1772 } 1773 1774 static void 1775 vm_object_collapse_scan(vm_object_t object) 1776 { 1777 vm_object_t backing_object; 1778 vm_page_t next, p, pp; 1779 vm_pindex_t backing_offset_index, new_pindex; 1780 1781 VM_OBJECT_ASSERT_WLOCKED(object); 1782 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1783 1784 backing_object = object->backing_object; 1785 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1786 1787 /* 1788 * Our scan 1789 */ 1790 for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) { 1791 next = TAILQ_NEXT(p, listq); 1792 new_pindex = p->pindex - backing_offset_index; 1793 1794 /* 1795 * Check for busy page 1796 */ 1797 if (vm_page_tryxbusy(p) == 0) { 1798 next = vm_object_collapse_scan_wait(object, p); 1799 continue; 1800 } 1801 1802 KASSERT(object->backing_object == backing_object, 1803 ("vm_object_collapse_scan: backing object mismatch %p != %p", 1804 object->backing_object, backing_object)); 1805 KASSERT(p->object == backing_object, 1806 ("vm_object_collapse_scan: object mismatch %p != %p", 1807 p->object, backing_object)); 1808 1809 if (p->pindex < backing_offset_index || 1810 new_pindex >= object->size) { 1811 vm_pager_freespace(backing_object, p->pindex, 1); 1812 1813 KASSERT(!pmap_page_is_mapped(p), 1814 ("freeing mapped page %p", p)); 1815 if (vm_page_remove(p)) 1816 vm_page_free(p); 1817 continue; 1818 } 1819 1820 if (!vm_page_all_valid(p)) { 1821 KASSERT(!pmap_page_is_mapped(p), 1822 ("freeing mapped page %p", p)); 1823 if (vm_page_remove(p)) 1824 vm_page_free(p); 1825 continue; 1826 } 1827 1828 pp = vm_page_lookup(object, new_pindex); 1829 if (pp != NULL && vm_page_tryxbusy(pp) == 0) { 1830 vm_page_xunbusy(p); 1831 /* 1832 * The page in the parent is busy and possibly not 1833 * (yet) valid. Until its state is finalized by the 1834 * busy bit owner, we can't tell whether it shadows the 1835 * original page. 1836 */ 1837 next = vm_object_collapse_scan_wait(object, pp); 1838 continue; 1839 } 1840 1841 if (pp != NULL && vm_page_none_valid(pp)) { 1842 /* 1843 * The page was invalid in the parent. Likely placed 1844 * there by an incomplete fault. Just remove and 1845 * ignore. p can replace it. 1846 */ 1847 if (vm_page_remove(pp)) 1848 vm_page_free(pp); 1849 pp = NULL; 1850 } 1851 1852 if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL, 1853 NULL)) { 1854 /* 1855 * The page already exists in the parent OR swap exists 1856 * for this location in the parent. Leave the parent's 1857 * page alone. Destroy the original page from the 1858 * backing object. 1859 */ 1860 vm_pager_freespace(backing_object, p->pindex, 1); 1861 KASSERT(!pmap_page_is_mapped(p), 1862 ("freeing mapped page %p", p)); 1863 if (vm_page_remove(p)) 1864 vm_page_free(p); 1865 if (pp != NULL) 1866 vm_page_xunbusy(pp); 1867 continue; 1868 } 1869 1870 /* 1871 * Page does not exist in parent, rename the page from the 1872 * backing object to the main object. 1873 * 1874 * If the page was mapped to a process, it can remain mapped 1875 * through the rename. vm_page_rename() will dirty the page. 1876 */ 1877 if (vm_page_rename(p, object, new_pindex)) { 1878 vm_page_xunbusy(p); 1879 next = vm_object_collapse_scan_wait(object, NULL); 1880 continue; 1881 } 1882 1883 /* Use the old pindex to free the right page. */ 1884 vm_pager_freespace(backing_object, new_pindex + 1885 backing_offset_index, 1); 1886 1887 #if VM_NRESERVLEVEL > 0 1888 /* 1889 * Rename the reservation. 1890 */ 1891 vm_reserv_rename(p, object, backing_object, 1892 backing_offset_index); 1893 #endif 1894 vm_page_xunbusy(p); 1895 } 1896 return; 1897 } 1898 1899 /* 1900 * vm_object_collapse: 1901 * 1902 * Collapse an object with the object backing it. 1903 * Pages in the backing object are moved into the 1904 * parent, and the backing object is deallocated. 1905 */ 1906 void 1907 vm_object_collapse(vm_object_t object) 1908 { 1909 vm_object_t backing_object, new_backing_object; 1910 1911 VM_OBJECT_ASSERT_WLOCKED(object); 1912 1913 while (TRUE) { 1914 KASSERT((object->flags & (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON, 1915 ("collapsing invalid object")); 1916 1917 /* 1918 * Wait for the backing_object to finish any pending 1919 * collapse so that the caller sees the shortest possible 1920 * shadow chain. 1921 */ 1922 backing_object = vm_object_backing_collapse_wait(object); 1923 if (backing_object == NULL) 1924 return; 1925 1926 KASSERT(object->ref_count > 0 && 1927 object->ref_count > object->shadow_count, 1928 ("collapse with invalid ref %d or shadow %d count.", 1929 object->ref_count, object->shadow_count)); 1930 KASSERT((backing_object->flags & 1931 (OBJ_COLLAPSING | OBJ_DEAD)) == 0, 1932 ("vm_object_collapse: Backing object already collapsing.")); 1933 KASSERT((object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0, 1934 ("vm_object_collapse: object is already collapsing.")); 1935 1936 /* 1937 * We know that we can either collapse the backing object if 1938 * the parent is the only reference to it, or (perhaps) have 1939 * the parent bypass the object if the parent happens to shadow 1940 * all the resident pages in the entire backing object. 1941 */ 1942 if (backing_object->ref_count == 1) { 1943 KASSERT(backing_object->shadow_count == 1, 1944 ("vm_object_collapse: shadow_count: %d", 1945 backing_object->shadow_count)); 1946 vm_object_pip_add(object, 1); 1947 vm_object_set_flag(object, OBJ_COLLAPSING); 1948 vm_object_pip_add(backing_object, 1); 1949 vm_object_set_flag(backing_object, OBJ_DEAD); 1950 1951 /* 1952 * If there is exactly one reference to the backing 1953 * object, we can collapse it into the parent. 1954 */ 1955 vm_object_collapse_scan(object); 1956 1957 #if VM_NRESERVLEVEL > 0 1958 /* 1959 * Break any reservations from backing_object. 1960 */ 1961 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1962 vm_reserv_break_all(backing_object); 1963 #endif 1964 1965 /* 1966 * Move the pager from backing_object to object. 1967 */ 1968 if ((backing_object->flags & OBJ_SWAP) != 0) { 1969 /* 1970 * swap_pager_copy() can sleep, in which case 1971 * the backing_object's and object's locks are 1972 * released and reacquired. 1973 * Since swap_pager_copy() is being asked to 1974 * destroy backing_object, it will change the 1975 * type to OBJT_DEFAULT. 1976 */ 1977 swap_pager_copy( 1978 backing_object, 1979 object, 1980 OFF_TO_IDX(object->backing_object_offset), TRUE); 1981 } 1982 1983 /* 1984 * Object now shadows whatever backing_object did. 1985 */ 1986 vm_object_clear_flag(object, OBJ_COLLAPSING); 1987 vm_object_backing_transfer(object, backing_object); 1988 object->backing_object_offset += 1989 backing_object->backing_object_offset; 1990 VM_OBJECT_WUNLOCK(object); 1991 vm_object_pip_wakeup(object); 1992 1993 /* 1994 * Discard backing_object. 1995 * 1996 * Since the backing object has no pages, no pager left, 1997 * and no object references within it, all that is 1998 * necessary is to dispose of it. 1999 */ 2000 KASSERT(backing_object->ref_count == 1, ( 2001 "backing_object %p was somehow re-referenced during collapse!", 2002 backing_object)); 2003 vm_object_pip_wakeup(backing_object); 2004 (void)refcount_release(&backing_object->ref_count); 2005 vm_object_terminate(backing_object); 2006 counter_u64_add(object_collapses, 1); 2007 VM_OBJECT_WLOCK(object); 2008 } else { 2009 /* 2010 * If we do not entirely shadow the backing object, 2011 * there is nothing we can do so we give up. 2012 * 2013 * The object lock and backing_object lock must not 2014 * be dropped during this sequence. 2015 */ 2016 if (!vm_object_scan_all_shadowed(object)) { 2017 VM_OBJECT_WUNLOCK(backing_object); 2018 break; 2019 } 2020 2021 /* 2022 * Make the parent shadow the next object in the 2023 * chain. Deallocating backing_object will not remove 2024 * it, since its reference count is at least 2. 2025 */ 2026 vm_object_backing_remove_locked(object); 2027 new_backing_object = backing_object->backing_object; 2028 if (new_backing_object != NULL) { 2029 vm_object_backing_insert_ref(object, 2030 new_backing_object); 2031 object->backing_object_offset += 2032 backing_object->backing_object_offset; 2033 } 2034 2035 /* 2036 * Drop the reference count on backing_object. Since 2037 * its ref_count was at least 2, it will not vanish. 2038 */ 2039 (void)refcount_release(&backing_object->ref_count); 2040 KASSERT(backing_object->ref_count >= 1, ( 2041 "backing_object %p was somehow dereferenced during collapse!", 2042 backing_object)); 2043 VM_OBJECT_WUNLOCK(backing_object); 2044 counter_u64_add(object_bypasses, 1); 2045 } 2046 2047 /* 2048 * Try again with this object's new backing object. 2049 */ 2050 } 2051 } 2052 2053 /* 2054 * vm_object_page_remove: 2055 * 2056 * For the given object, either frees or invalidates each of the 2057 * specified pages. In general, a page is freed. However, if a page is 2058 * wired for any reason other than the existence of a managed, wired 2059 * mapping, then it may be invalidated but not removed from the object. 2060 * Pages are specified by the given range ["start", "end") and the option 2061 * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range 2062 * extends from "start" to the end of the object. If the option 2063 * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the 2064 * specified range are affected. If the option OBJPR_NOTMAPPED is 2065 * specified, then the pages within the specified range must have no 2066 * mappings. Otherwise, if this option is not specified, any mappings to 2067 * the specified pages are removed before the pages are freed or 2068 * invalidated. 2069 * 2070 * In general, this operation should only be performed on objects that 2071 * contain managed pages. There are, however, two exceptions. First, it 2072 * is performed on the kernel and kmem objects by vm_map_entry_delete(). 2073 * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device- 2074 * backed pages. In both of these cases, the option OBJPR_CLEANONLY must 2075 * not be specified and the option OBJPR_NOTMAPPED must be specified. 2076 * 2077 * The object must be locked. 2078 */ 2079 void 2080 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 2081 int options) 2082 { 2083 vm_page_t p, next; 2084 2085 VM_OBJECT_ASSERT_WLOCKED(object); 2086 KASSERT((object->flags & OBJ_UNMANAGED) == 0 || 2087 (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED, 2088 ("vm_object_page_remove: illegal options for object %p", object)); 2089 if (object->resident_page_count == 0) 2090 return; 2091 vm_object_pip_add(object, 1); 2092 again: 2093 p = vm_page_find_least(object, start); 2094 2095 /* 2096 * Here, the variable "p" is either (1) the page with the least pindex 2097 * greater than or equal to the parameter "start" or (2) NULL. 2098 */ 2099 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 2100 next = TAILQ_NEXT(p, listq); 2101 2102 /* 2103 * Skip invalid pages if asked to do so. Try to avoid acquiring 2104 * the busy lock, as some consumers rely on this to avoid 2105 * deadlocks. 2106 * 2107 * A thread may concurrently transition the page from invalid to 2108 * valid using only the busy lock, so the result of this check 2109 * is immediately stale. It is up to consumers to handle this, 2110 * for instance by ensuring that all invalid->valid transitions 2111 * happen with a mutex held, as may be possible for a 2112 * filesystem. 2113 */ 2114 if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) 2115 continue; 2116 2117 /* 2118 * If the page is wired for any reason besides the existence 2119 * of managed, wired mappings, then it cannot be freed. For 2120 * example, fictitious pages, which represent device memory, 2121 * are inherently wired and cannot be freed. They can, 2122 * however, be invalidated if the option OBJPR_CLEANONLY is 2123 * not specified. 2124 */ 2125 if (vm_page_tryxbusy(p) == 0) { 2126 if (vm_page_busy_sleep(p, "vmopar", 0)) 2127 VM_OBJECT_WLOCK(object); 2128 goto again; 2129 } 2130 if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) { 2131 vm_page_xunbusy(p); 2132 continue; 2133 } 2134 if (vm_page_wired(p)) { 2135 wired: 2136 if ((options & OBJPR_NOTMAPPED) == 0 && 2137 object->ref_count != 0) 2138 pmap_remove_all(p); 2139 if ((options & OBJPR_CLEANONLY) == 0) { 2140 vm_page_invalid(p); 2141 vm_page_undirty(p); 2142 } 2143 vm_page_xunbusy(p); 2144 continue; 2145 } 2146 KASSERT((p->flags & PG_FICTITIOUS) == 0, 2147 ("vm_object_page_remove: page %p is fictitious", p)); 2148 if ((options & OBJPR_CLEANONLY) != 0 && 2149 !vm_page_none_valid(p)) { 2150 if ((options & OBJPR_NOTMAPPED) == 0 && 2151 object->ref_count != 0 && 2152 !vm_page_try_remove_write(p)) 2153 goto wired; 2154 if (p->dirty != 0) { 2155 vm_page_xunbusy(p); 2156 continue; 2157 } 2158 } 2159 if ((options & OBJPR_NOTMAPPED) == 0 && 2160 object->ref_count != 0 && !vm_page_try_remove_all(p)) 2161 goto wired; 2162 vm_page_free(p); 2163 } 2164 vm_object_pip_wakeup(object); 2165 2166 vm_pager_freespace(object, start, (end == 0 ? object->size : end) - 2167 start); 2168 } 2169 2170 /* 2171 * vm_object_page_noreuse: 2172 * 2173 * For the given object, attempt to move the specified pages to 2174 * the head of the inactive queue. This bypasses regular LRU 2175 * operation and allows the pages to be reused quickly under memory 2176 * pressure. If a page is wired for any reason, then it will not 2177 * be queued. Pages are specified by the range ["start", "end"). 2178 * As a special case, if "end" is zero, then the range extends from 2179 * "start" to the end of the object. 2180 * 2181 * This operation should only be performed on objects that 2182 * contain non-fictitious, managed pages. 2183 * 2184 * The object must be locked. 2185 */ 2186 void 2187 vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2188 { 2189 vm_page_t p, next; 2190 2191 VM_OBJECT_ASSERT_LOCKED(object); 2192 KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0, 2193 ("vm_object_page_noreuse: illegal object %p", object)); 2194 if (object->resident_page_count == 0) 2195 return; 2196 p = vm_page_find_least(object, start); 2197 2198 /* 2199 * Here, the variable "p" is either (1) the page with the least pindex 2200 * greater than or equal to the parameter "start" or (2) NULL. 2201 */ 2202 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 2203 next = TAILQ_NEXT(p, listq); 2204 vm_page_deactivate_noreuse(p); 2205 } 2206 } 2207 2208 /* 2209 * Populate the specified range of the object with valid pages. Returns 2210 * TRUE if the range is successfully populated and FALSE otherwise. 2211 * 2212 * Note: This function should be optimized to pass a larger array of 2213 * pages to vm_pager_get_pages() before it is applied to a non- 2214 * OBJT_DEVICE object. 2215 * 2216 * The object must be locked. 2217 */ 2218 boolean_t 2219 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2220 { 2221 vm_page_t m; 2222 vm_pindex_t pindex; 2223 int rv; 2224 2225 VM_OBJECT_ASSERT_WLOCKED(object); 2226 for (pindex = start; pindex < end; pindex++) { 2227 rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL); 2228 if (rv != VM_PAGER_OK) 2229 break; 2230 2231 /* 2232 * Keep "m" busy because a subsequent iteration may unlock 2233 * the object. 2234 */ 2235 } 2236 if (pindex > start) { 2237 m = vm_page_lookup(object, start); 2238 while (m != NULL && m->pindex < pindex) { 2239 vm_page_xunbusy(m); 2240 m = TAILQ_NEXT(m, listq); 2241 } 2242 } 2243 return (pindex == end); 2244 } 2245 2246 /* 2247 * Routine: vm_object_coalesce 2248 * Function: Coalesces two objects backing up adjoining 2249 * regions of memory into a single object. 2250 * 2251 * returns TRUE if objects were combined. 2252 * 2253 * NOTE: Only works at the moment if the second object is NULL - 2254 * if it's not, which object do we lock first? 2255 * 2256 * Parameters: 2257 * prev_object First object to coalesce 2258 * prev_offset Offset into prev_object 2259 * prev_size Size of reference to prev_object 2260 * next_size Size of reference to the second object 2261 * reserved Indicator that extension region has 2262 * swap accounted for 2263 * 2264 * Conditions: 2265 * The object must *not* be locked. 2266 */ 2267 boolean_t 2268 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2269 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2270 { 2271 vm_pindex_t next_pindex; 2272 2273 if (prev_object == NULL) 2274 return (TRUE); 2275 if ((prev_object->flags & OBJ_ANON) == 0) 2276 return (FALSE); 2277 2278 VM_OBJECT_WLOCK(prev_object); 2279 /* 2280 * Try to collapse the object first. 2281 */ 2282 vm_object_collapse(prev_object); 2283 2284 /* 2285 * Can't coalesce if: . more than one reference . paged out . shadows 2286 * another object . has a copy elsewhere (any of which mean that the 2287 * pages not mapped to prev_entry may be in use anyway) 2288 */ 2289 if (prev_object->backing_object != NULL) { 2290 VM_OBJECT_WUNLOCK(prev_object); 2291 return (FALSE); 2292 } 2293 2294 prev_size >>= PAGE_SHIFT; 2295 next_size >>= PAGE_SHIFT; 2296 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2297 2298 if (prev_object->ref_count > 1 && 2299 prev_object->size != next_pindex && 2300 (prev_object->flags & OBJ_ONEMAPPING) == 0) { 2301 VM_OBJECT_WUNLOCK(prev_object); 2302 return (FALSE); 2303 } 2304 2305 /* 2306 * Account for the charge. 2307 */ 2308 if (prev_object->cred != NULL) { 2309 /* 2310 * If prev_object was charged, then this mapping, 2311 * although not charged now, may become writable 2312 * later. Non-NULL cred in the object would prevent 2313 * swap reservation during enabling of the write 2314 * access, so reserve swap now. Failed reservation 2315 * cause allocation of the separate object for the map 2316 * entry, and swap reservation for this entry is 2317 * managed in appropriate time. 2318 */ 2319 if (!reserved && !swap_reserve_by_cred(ptoa(next_size), 2320 prev_object->cred)) { 2321 VM_OBJECT_WUNLOCK(prev_object); 2322 return (FALSE); 2323 } 2324 prev_object->charge += ptoa(next_size); 2325 } 2326 2327 /* 2328 * Remove any pages that may still be in the object from a previous 2329 * deallocation. 2330 */ 2331 if (next_pindex < prev_object->size) { 2332 vm_object_page_remove(prev_object, next_pindex, next_pindex + 2333 next_size, 0); 2334 #if 0 2335 if (prev_object->cred != NULL) { 2336 KASSERT(prev_object->charge >= 2337 ptoa(prev_object->size - next_pindex), 2338 ("object %p overcharged 1 %jx %jx", prev_object, 2339 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2340 prev_object->charge -= ptoa(prev_object->size - 2341 next_pindex); 2342 } 2343 #endif 2344 } 2345 2346 /* 2347 * Extend the object if necessary. 2348 */ 2349 if (next_pindex + next_size > prev_object->size) 2350 prev_object->size = next_pindex + next_size; 2351 2352 VM_OBJECT_WUNLOCK(prev_object); 2353 return (TRUE); 2354 } 2355 2356 void 2357 vm_object_set_writeable_dirty_(vm_object_t object) 2358 { 2359 atomic_add_int(&object->generation, 1); 2360 } 2361 2362 bool 2363 vm_object_mightbedirty_(vm_object_t object) 2364 { 2365 return (object->generation != object->cleangeneration); 2366 } 2367 2368 /* 2369 * vm_object_unwire: 2370 * 2371 * For each page offset within the specified range of the given object, 2372 * find the highest-level page in the shadow chain and unwire it. A page 2373 * must exist at every page offset, and the highest-level page must be 2374 * wired. 2375 */ 2376 void 2377 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length, 2378 uint8_t queue) 2379 { 2380 vm_object_t tobject, t1object; 2381 vm_page_t m, tm; 2382 vm_pindex_t end_pindex, pindex, tpindex; 2383 int depth, locked_depth; 2384 2385 KASSERT((offset & PAGE_MASK) == 0, 2386 ("vm_object_unwire: offset is not page aligned")); 2387 KASSERT((length & PAGE_MASK) == 0, 2388 ("vm_object_unwire: length is not a multiple of PAGE_SIZE")); 2389 /* The wired count of a fictitious page never changes. */ 2390 if ((object->flags & OBJ_FICTITIOUS) != 0) 2391 return; 2392 pindex = OFF_TO_IDX(offset); 2393 end_pindex = pindex + atop(length); 2394 again: 2395 locked_depth = 1; 2396 VM_OBJECT_RLOCK(object); 2397 m = vm_page_find_least(object, pindex); 2398 while (pindex < end_pindex) { 2399 if (m == NULL || pindex < m->pindex) { 2400 /* 2401 * The first object in the shadow chain doesn't 2402 * contain a page at the current index. Therefore, 2403 * the page must exist in a backing object. 2404 */ 2405 tobject = object; 2406 tpindex = pindex; 2407 depth = 0; 2408 do { 2409 tpindex += 2410 OFF_TO_IDX(tobject->backing_object_offset); 2411 tobject = tobject->backing_object; 2412 KASSERT(tobject != NULL, 2413 ("vm_object_unwire: missing page")); 2414 if ((tobject->flags & OBJ_FICTITIOUS) != 0) 2415 goto next_page; 2416 depth++; 2417 if (depth == locked_depth) { 2418 locked_depth++; 2419 VM_OBJECT_RLOCK(tobject); 2420 } 2421 } while ((tm = vm_page_lookup(tobject, tpindex)) == 2422 NULL); 2423 } else { 2424 tm = m; 2425 m = TAILQ_NEXT(m, listq); 2426 } 2427 if (vm_page_trysbusy(tm) == 0) { 2428 for (tobject = object; locked_depth >= 1; 2429 locked_depth--) { 2430 t1object = tobject->backing_object; 2431 if (tm->object != tobject) 2432 VM_OBJECT_RUNLOCK(tobject); 2433 tobject = t1object; 2434 } 2435 tobject = tm->object; 2436 if (!vm_page_busy_sleep(tm, "unwbo", 2437 VM_ALLOC_IGN_SBUSY)) 2438 VM_OBJECT_RUNLOCK(tobject); 2439 goto again; 2440 } 2441 vm_page_unwire(tm, queue); 2442 vm_page_sunbusy(tm); 2443 next_page: 2444 pindex++; 2445 } 2446 /* Release the accumulated object locks. */ 2447 for (tobject = object; locked_depth >= 1; locked_depth--) { 2448 t1object = tobject->backing_object; 2449 VM_OBJECT_RUNLOCK(tobject); 2450 tobject = t1object; 2451 } 2452 } 2453 2454 /* 2455 * Return the vnode for the given object, or NULL if none exists. 2456 * For tmpfs objects, the function may return NULL if there is 2457 * no vnode allocated at the time of the call. 2458 */ 2459 struct vnode * 2460 vm_object_vnode(vm_object_t object) 2461 { 2462 struct vnode *vp; 2463 2464 VM_OBJECT_ASSERT_LOCKED(object); 2465 vm_pager_getvp(object, &vp, NULL); 2466 return (vp); 2467 } 2468 2469 /* 2470 * Busy the vm object. This prevents new pages belonging to the object from 2471 * becoming busy. Existing pages persist as busy. Callers are responsible 2472 * for checking page state before proceeding. 2473 */ 2474 void 2475 vm_object_busy(vm_object_t obj) 2476 { 2477 2478 VM_OBJECT_ASSERT_LOCKED(obj); 2479 2480 blockcount_acquire(&obj->busy, 1); 2481 /* The fence is required to order loads of page busy. */ 2482 atomic_thread_fence_acq_rel(); 2483 } 2484 2485 void 2486 vm_object_unbusy(vm_object_t obj) 2487 { 2488 2489 blockcount_release(&obj->busy, 1); 2490 } 2491 2492 void 2493 vm_object_busy_wait(vm_object_t obj, const char *wmesg) 2494 { 2495 2496 VM_OBJECT_ASSERT_UNLOCKED(obj); 2497 2498 (void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM); 2499 } 2500 2501 static int 2502 vm_object_list_handler(struct sysctl_req *req, bool swap_only) 2503 { 2504 struct kinfo_vmobject *kvo; 2505 char *fullpath, *freepath; 2506 struct vnode *vp; 2507 struct vattr va; 2508 vm_object_t obj; 2509 vm_page_t m; 2510 u_long sp; 2511 int count, error; 2512 2513 if (req->oldptr == NULL) { 2514 /* 2515 * If an old buffer has not been provided, generate an 2516 * estimate of the space needed for a subsequent call. 2517 */ 2518 mtx_lock(&vm_object_list_mtx); 2519 count = 0; 2520 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2521 if (obj->type == OBJT_DEAD) 2522 continue; 2523 count++; 2524 } 2525 mtx_unlock(&vm_object_list_mtx); 2526 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) * 2527 count * 11 / 10)); 2528 } 2529 2530 kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK); 2531 error = 0; 2532 2533 /* 2534 * VM objects are type stable and are never removed from the 2535 * list once added. This allows us to safely read obj->object_list 2536 * after reacquiring the VM object lock. 2537 */ 2538 mtx_lock(&vm_object_list_mtx); 2539 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2540 if (obj->type == OBJT_DEAD || 2541 (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) 2542 continue; 2543 VM_OBJECT_RLOCK(obj); 2544 if (obj->type == OBJT_DEAD || 2545 (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) { 2546 VM_OBJECT_RUNLOCK(obj); 2547 continue; 2548 } 2549 mtx_unlock(&vm_object_list_mtx); 2550 kvo->kvo_size = ptoa(obj->size); 2551 kvo->kvo_resident = obj->resident_page_count; 2552 kvo->kvo_ref_count = obj->ref_count; 2553 kvo->kvo_shadow_count = obj->shadow_count; 2554 kvo->kvo_memattr = obj->memattr; 2555 kvo->kvo_active = 0; 2556 kvo->kvo_inactive = 0; 2557 if (!swap_only) { 2558 TAILQ_FOREACH(m, &obj->memq, listq) { 2559 /* 2560 * A page may belong to the object but be 2561 * dequeued and set to PQ_NONE while the 2562 * object lock is not held. This makes the 2563 * reads of m->queue below racy, and we do not 2564 * count pages set to PQ_NONE. However, this 2565 * sysctl is only meant to give an 2566 * approximation of the system anyway. 2567 */ 2568 if (m->a.queue == PQ_ACTIVE) 2569 kvo->kvo_active++; 2570 else if (m->a.queue == PQ_INACTIVE) 2571 kvo->kvo_inactive++; 2572 } 2573 } 2574 2575 kvo->kvo_vn_fileid = 0; 2576 kvo->kvo_vn_fsid = 0; 2577 kvo->kvo_vn_fsid_freebsd11 = 0; 2578 freepath = NULL; 2579 fullpath = ""; 2580 vp = NULL; 2581 kvo->kvo_type = vm_object_kvme_type(obj, swap_only ? NULL : &vp); 2582 if (vp != NULL) { 2583 vref(vp); 2584 } else if ((obj->flags & OBJ_ANON) != 0) { 2585 MPASS(kvo->kvo_type == KVME_TYPE_DEFAULT || 2586 kvo->kvo_type == KVME_TYPE_SWAP); 2587 kvo->kvo_me = (uintptr_t)obj; 2588 /* tmpfs objs are reported as vnodes */ 2589 kvo->kvo_backing_obj = (uintptr_t)obj->backing_object; 2590 sp = swap_pager_swapped_pages(obj); 2591 kvo->kvo_swapped = sp > UINT32_MAX ? UINT32_MAX : sp; 2592 } 2593 VM_OBJECT_RUNLOCK(obj); 2594 if (vp != NULL) { 2595 vn_fullpath(vp, &fullpath, &freepath); 2596 vn_lock(vp, LK_SHARED | LK_RETRY); 2597 if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) { 2598 kvo->kvo_vn_fileid = va.va_fileid; 2599 kvo->kvo_vn_fsid = va.va_fsid; 2600 kvo->kvo_vn_fsid_freebsd11 = va.va_fsid; 2601 /* truncate */ 2602 } 2603 vput(vp); 2604 } 2605 2606 strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path)); 2607 if (freepath != NULL) 2608 free(freepath, M_TEMP); 2609 2610 /* Pack record size down */ 2611 kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path) 2612 + strlen(kvo->kvo_path) + 1; 2613 kvo->kvo_structsize = roundup(kvo->kvo_structsize, 2614 sizeof(uint64_t)); 2615 error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize); 2616 maybe_yield(); 2617 mtx_lock(&vm_object_list_mtx); 2618 if (error) 2619 break; 2620 } 2621 mtx_unlock(&vm_object_list_mtx); 2622 free(kvo, M_TEMP); 2623 return (error); 2624 } 2625 2626 static int 2627 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS) 2628 { 2629 return (vm_object_list_handler(req, false)); 2630 } 2631 2632 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | 2633 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject", 2634 "List of VM objects"); 2635 2636 static int 2637 sysctl_vm_object_list_swap(SYSCTL_HANDLER_ARGS) 2638 { 2639 return (vm_object_list_handler(req, true)); 2640 } 2641 2642 /* 2643 * This sysctl returns list of the anonymous or swap objects. Intent 2644 * is to provide stripped optimized list useful to analyze swap use. 2645 * Since technically non-swap (default) objects participate in the 2646 * shadow chains, and are converted to swap type as needed by swap 2647 * pager, we must report them. 2648 */ 2649 SYSCTL_PROC(_vm, OID_AUTO, swap_objects, 2650 CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, NULL, 0, 2651 sysctl_vm_object_list_swap, "S,kinfo_vmobject", 2652 "List of swap VM objects"); 2653 2654 #include "opt_ddb.h" 2655 #ifdef DDB 2656 #include <sys/kernel.h> 2657 2658 #include <sys/cons.h> 2659 2660 #include <ddb/ddb.h> 2661 2662 static int 2663 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2664 { 2665 vm_map_t tmpm; 2666 vm_map_entry_t tmpe; 2667 vm_object_t obj; 2668 2669 if (map == 0) 2670 return 0; 2671 2672 if (entry == 0) { 2673 VM_MAP_ENTRY_FOREACH(tmpe, map) { 2674 if (_vm_object_in_map(map, object, tmpe)) { 2675 return 1; 2676 } 2677 } 2678 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2679 tmpm = entry->object.sub_map; 2680 VM_MAP_ENTRY_FOREACH(tmpe, tmpm) { 2681 if (_vm_object_in_map(tmpm, object, tmpe)) { 2682 return 1; 2683 } 2684 } 2685 } else if ((obj = entry->object.vm_object) != NULL) { 2686 for (; obj; obj = obj->backing_object) 2687 if (obj == object) { 2688 return 1; 2689 } 2690 } 2691 return 0; 2692 } 2693 2694 static int 2695 vm_object_in_map(vm_object_t object) 2696 { 2697 struct proc *p; 2698 2699 /* sx_slock(&allproc_lock); */ 2700 FOREACH_PROC_IN_SYSTEM(p) { 2701 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2702 continue; 2703 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2704 /* sx_sunlock(&allproc_lock); */ 2705 return 1; 2706 } 2707 } 2708 /* sx_sunlock(&allproc_lock); */ 2709 if (_vm_object_in_map(kernel_map, object, 0)) 2710 return 1; 2711 return 0; 2712 } 2713 2714 DB_SHOW_COMMAND(vmochk, vm_object_check) 2715 { 2716 vm_object_t object; 2717 2718 /* 2719 * make sure that internal objs are in a map somewhere 2720 * and none have zero ref counts. 2721 */ 2722 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2723 if ((object->flags & OBJ_ANON) != 0) { 2724 if (object->ref_count == 0) { 2725 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2726 (long)object->size); 2727 } 2728 if (!vm_object_in_map(object)) { 2729 db_printf( 2730 "vmochk: internal obj is not in a map: " 2731 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2732 object->ref_count, (u_long)object->size, 2733 (u_long)object->size, 2734 (void *)object->backing_object); 2735 } 2736 } 2737 if (db_pager_quit) 2738 return; 2739 } 2740 } 2741 2742 /* 2743 * vm_object_print: [ debug ] 2744 */ 2745 DB_SHOW_COMMAND(object, vm_object_print_static) 2746 { 2747 /* XXX convert args. */ 2748 vm_object_t object = (vm_object_t)addr; 2749 boolean_t full = have_addr; 2750 2751 vm_page_t p; 2752 2753 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2754 #define count was_count 2755 2756 int count; 2757 2758 if (object == NULL) 2759 return; 2760 2761 db_iprintf( 2762 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n", 2763 object, (int)object->type, (uintmax_t)object->size, 2764 object->resident_page_count, object->ref_count, object->flags, 2765 object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge); 2766 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2767 object->shadow_count, 2768 object->backing_object ? object->backing_object->ref_count : 0, 2769 object->backing_object, (uintmax_t)object->backing_object_offset); 2770 2771 if (!full) 2772 return; 2773 2774 db_indent += 2; 2775 count = 0; 2776 TAILQ_FOREACH(p, &object->memq, listq) { 2777 if (count == 0) 2778 db_iprintf("memory:="); 2779 else if (count == 6) { 2780 db_printf("\n"); 2781 db_iprintf(" ..."); 2782 count = 0; 2783 } else 2784 db_printf(","); 2785 count++; 2786 2787 db_printf("(off=0x%jx,page=0x%jx)", 2788 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2789 2790 if (db_pager_quit) 2791 break; 2792 } 2793 if (count != 0) 2794 db_printf("\n"); 2795 db_indent -= 2; 2796 } 2797 2798 /* XXX. */ 2799 #undef count 2800 2801 /* XXX need this non-static entry for calling from vm_map_print. */ 2802 void 2803 vm_object_print( 2804 /* db_expr_t */ long addr, 2805 boolean_t have_addr, 2806 /* db_expr_t */ long count, 2807 char *modif) 2808 { 2809 vm_object_print_static(addr, have_addr, count, modif); 2810 } 2811 2812 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2813 { 2814 vm_object_t object; 2815 vm_pindex_t fidx; 2816 vm_paddr_t pa; 2817 vm_page_t m, prev_m; 2818 int rcount, nl, c; 2819 2820 nl = 0; 2821 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2822 db_printf("new object: %p\n", (void *)object); 2823 if (nl > 18) { 2824 c = cngetc(); 2825 if (c != ' ') 2826 return; 2827 nl = 0; 2828 } 2829 nl++; 2830 rcount = 0; 2831 fidx = 0; 2832 pa = -1; 2833 TAILQ_FOREACH(m, &object->memq, listq) { 2834 if (m->pindex > 128) 2835 break; 2836 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2837 prev_m->pindex + 1 != m->pindex) { 2838 if (rcount) { 2839 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2840 (long)fidx, rcount, (long)pa); 2841 if (nl > 18) { 2842 c = cngetc(); 2843 if (c != ' ') 2844 return; 2845 nl = 0; 2846 } 2847 nl++; 2848 rcount = 0; 2849 } 2850 } 2851 if (rcount && 2852 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2853 ++rcount; 2854 continue; 2855 } 2856 if (rcount) { 2857 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2858 (long)fidx, rcount, (long)pa); 2859 if (nl > 18) { 2860 c = cngetc(); 2861 if (c != ' ') 2862 return; 2863 nl = 0; 2864 } 2865 nl++; 2866 } 2867 fidx = m->pindex; 2868 pa = VM_PAGE_TO_PHYS(m); 2869 rcount = 1; 2870 } 2871 if (rcount) { 2872 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2873 (long)fidx, rcount, (long)pa); 2874 if (nl > 18) { 2875 c = cngetc(); 2876 if (c != ' ') 2877 return; 2878 nl = 0; 2879 } 2880 nl++; 2881 } 2882 } 2883 } 2884 #endif /* DDB */ 2885