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