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 * We dropped a reference on an object and discovered that it had a 561 * single remaining shadow. This is a sibling of the reference we 562 * dropped. Attempt to collapse the sibling and backing object. 563 */ 564 static vm_object_t 565 vm_object_deallocate_anon(vm_object_t backing_object) 566 { 567 vm_object_t object; 568 569 /* Fetch the final shadow. */ 570 object = LIST_FIRST(&backing_object->shadow_head); 571 KASSERT(object != NULL && backing_object->shadow_count == 1, 572 ("vm_object_anon_deallocate: ref_count: %d, shadow_count: %d", 573 backing_object->ref_count, backing_object->shadow_count)); 574 KASSERT((object->flags & (OBJ_TMPFS_NODE | OBJ_ANON)) == OBJ_ANON, 575 ("invalid shadow object %p", object)); 576 577 if (!VM_OBJECT_TRYWLOCK(object)) { 578 /* 579 * Prevent object from disappearing since we do not have a 580 * reference. 581 */ 582 vm_object_pip_add(object, 1); 583 VM_OBJECT_WUNLOCK(backing_object); 584 VM_OBJECT_WLOCK(object); 585 vm_object_pip_wakeup(object); 586 } else 587 VM_OBJECT_WUNLOCK(backing_object); 588 589 /* 590 * Check for a collapse/terminate race with the last reference holder. 591 */ 592 if ((object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) != 0 || 593 !refcount_acquire_if_not_zero(&object->ref_count)) { 594 VM_OBJECT_WUNLOCK(object); 595 return (NULL); 596 } 597 backing_object = object->backing_object; 598 if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0) 599 vm_object_collapse(object); 600 VM_OBJECT_WUNLOCK(object); 601 602 return (object); 603 } 604 605 /* 606 * vm_object_deallocate: 607 * 608 * Release a reference to the specified object, 609 * gained either through a vm_object_allocate 610 * or a vm_object_reference call. When all references 611 * are gone, storage associated with this object 612 * may be relinquished. 613 * 614 * No object may be locked. 615 */ 616 void 617 vm_object_deallocate(vm_object_t object) 618 { 619 vm_object_t temp; 620 bool released; 621 622 while (object != NULL) { 623 /* 624 * If the reference count goes to 0 we start calling 625 * vm_object_terminate() on the object chain. A ref count 626 * of 1 may be a special case depending on the shadow count 627 * being 0 or 1. These cases require a write lock on the 628 * object. 629 */ 630 if ((object->flags & OBJ_ANON) == 0) 631 released = refcount_release_if_gt(&object->ref_count, 1); 632 else 633 released = refcount_release_if_gt(&object->ref_count, 2); 634 if (released) 635 return; 636 637 if (object->type == OBJT_VNODE) { 638 VM_OBJECT_RLOCK(object); 639 if (object->type == OBJT_VNODE) { 640 vm_object_deallocate_vnode(object); 641 return; 642 } 643 VM_OBJECT_RUNLOCK(object); 644 } 645 646 VM_OBJECT_WLOCK(object); 647 KASSERT(object->ref_count > 0, 648 ("vm_object_deallocate: object deallocated too many times: %d", 649 object->type)); 650 651 /* 652 * If this is not the final reference to an anonymous 653 * object we may need to collapse the shadow chain. 654 */ 655 if (!refcount_release(&object->ref_count)) { 656 if (object->ref_count > 1 || 657 object->shadow_count == 0) { 658 if ((object->flags & OBJ_ANON) != 0 && 659 object->ref_count == 1) 660 vm_object_set_flag(object, 661 OBJ_ONEMAPPING); 662 VM_OBJECT_WUNLOCK(object); 663 return; 664 } 665 666 /* Handle collapsing last ref on anonymous objects. */ 667 object = vm_object_deallocate_anon(object); 668 continue; 669 } 670 671 /* 672 * Handle the final reference to an object. We restart 673 * the loop with the backing object to avoid recursion. 674 */ 675 umtx_shm_object_terminated(object); 676 temp = object->backing_object; 677 if (temp != NULL) { 678 KASSERT((object->flags & OBJ_TMPFS_NODE) == 0, 679 ("shadowed tmpfs v_object 2 %p", object)); 680 vm_object_backing_remove(object); 681 } 682 683 KASSERT((object->flags & OBJ_DEAD) == 0, 684 ("vm_object_deallocate: Terminating dead object.")); 685 vm_object_set_flag(object, OBJ_DEAD); 686 vm_object_terminate(object); 687 object = temp; 688 } 689 } 690 691 /* 692 * vm_object_destroy removes the object from the global object list 693 * and frees the space for the object. 694 */ 695 void 696 vm_object_destroy(vm_object_t object) 697 { 698 699 /* 700 * Release the allocation charge. 701 */ 702 if (object->cred != NULL) { 703 swap_release_by_cred(object->charge, object->cred); 704 object->charge = 0; 705 crfree(object->cred); 706 object->cred = NULL; 707 } 708 709 /* 710 * Free the space for the object. 711 */ 712 uma_zfree(obj_zone, object); 713 } 714 715 static void 716 vm_object_backing_remove_locked(vm_object_t object) 717 { 718 vm_object_t backing_object; 719 720 backing_object = object->backing_object; 721 VM_OBJECT_ASSERT_WLOCKED(object); 722 VM_OBJECT_ASSERT_WLOCKED(backing_object); 723 724 KASSERT((object->flags & OBJ_COLLAPSING) == 0, 725 ("vm_object_backing_remove: Removing collapsing object.")); 726 727 if ((object->flags & OBJ_SHADOWLIST) != 0) { 728 LIST_REMOVE(object, shadow_list); 729 backing_object->shadow_count--; 730 object->flags &= ~OBJ_SHADOWLIST; 731 } 732 object->backing_object = NULL; 733 } 734 735 static void 736 vm_object_backing_remove(vm_object_t object) 737 { 738 vm_object_t backing_object; 739 740 VM_OBJECT_ASSERT_WLOCKED(object); 741 742 if ((object->flags & OBJ_SHADOWLIST) != 0) { 743 backing_object = object->backing_object; 744 VM_OBJECT_WLOCK(backing_object); 745 vm_object_backing_remove_locked(object); 746 VM_OBJECT_WUNLOCK(backing_object); 747 } else 748 object->backing_object = NULL; 749 } 750 751 static void 752 vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object) 753 { 754 755 VM_OBJECT_ASSERT_WLOCKED(object); 756 757 if ((backing_object->flags & OBJ_ANON) != 0) { 758 VM_OBJECT_ASSERT_WLOCKED(backing_object); 759 LIST_INSERT_HEAD(&backing_object->shadow_head, object, 760 shadow_list); 761 backing_object->shadow_count++; 762 object->flags |= OBJ_SHADOWLIST; 763 } 764 object->backing_object = backing_object; 765 } 766 767 static void 768 vm_object_backing_insert(vm_object_t object, vm_object_t backing_object) 769 { 770 771 VM_OBJECT_ASSERT_WLOCKED(object); 772 773 if ((backing_object->flags & OBJ_ANON) != 0) { 774 VM_OBJECT_WLOCK(backing_object); 775 vm_object_backing_insert_locked(object, backing_object); 776 VM_OBJECT_WUNLOCK(backing_object); 777 } else 778 object->backing_object = backing_object; 779 } 780 781 /* 782 * Insert an object into a backing_object's shadow list with an additional 783 * reference to the backing_object added. 784 */ 785 static void 786 vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object) 787 { 788 789 VM_OBJECT_ASSERT_WLOCKED(object); 790 791 if ((backing_object->flags & OBJ_ANON) != 0) { 792 VM_OBJECT_WLOCK(backing_object); 793 KASSERT((backing_object->flags & OBJ_DEAD) == 0, 794 ("shadowing dead anonymous object")); 795 vm_object_reference_locked(backing_object); 796 vm_object_backing_insert_locked(object, backing_object); 797 vm_object_clear_flag(backing_object, OBJ_ONEMAPPING); 798 VM_OBJECT_WUNLOCK(backing_object); 799 } else { 800 vm_object_reference(backing_object); 801 object->backing_object = backing_object; 802 } 803 } 804 805 /* 806 * Transfer a backing reference from backing_object to object. 807 */ 808 static void 809 vm_object_backing_transfer(vm_object_t object, vm_object_t backing_object) 810 { 811 vm_object_t new_backing_object; 812 813 /* 814 * Note that the reference to backing_object->backing_object 815 * moves from within backing_object to within object. 816 */ 817 vm_object_backing_remove_locked(object); 818 new_backing_object = backing_object->backing_object; 819 if (new_backing_object == NULL) 820 return; 821 if ((new_backing_object->flags & OBJ_ANON) != 0) { 822 VM_OBJECT_WLOCK(new_backing_object); 823 vm_object_backing_remove_locked(backing_object); 824 vm_object_backing_insert_locked(object, new_backing_object); 825 VM_OBJECT_WUNLOCK(new_backing_object); 826 } else { 827 object->backing_object = new_backing_object; 828 backing_object->backing_object = NULL; 829 } 830 } 831 832 /* 833 * Wait for a concurrent collapse to settle. 834 */ 835 static void 836 vm_object_collapse_wait(vm_object_t object) 837 { 838 839 VM_OBJECT_ASSERT_WLOCKED(object); 840 841 while ((object->flags & OBJ_COLLAPSING) != 0) { 842 vm_object_pip_wait(object, "vmcolwait"); 843 counter_u64_add(object_collapse_waits, 1); 844 } 845 } 846 847 /* 848 * Waits for a backing object to clear a pending collapse and returns 849 * it locked if it is an ANON object. 850 */ 851 static vm_object_t 852 vm_object_backing_collapse_wait(vm_object_t object) 853 { 854 vm_object_t backing_object; 855 856 VM_OBJECT_ASSERT_WLOCKED(object); 857 858 for (;;) { 859 backing_object = object->backing_object; 860 if (backing_object == NULL || 861 (backing_object->flags & OBJ_ANON) == 0) 862 return (NULL); 863 VM_OBJECT_WLOCK(backing_object); 864 if ((backing_object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) == 0) 865 break; 866 VM_OBJECT_WUNLOCK(object); 867 vm_object_pip_sleep(backing_object, "vmbckwait"); 868 counter_u64_add(object_collapse_waits, 1); 869 VM_OBJECT_WLOCK(object); 870 } 871 return (backing_object); 872 } 873 874 /* 875 * vm_object_terminate_pages removes any remaining pageable pages 876 * from the object and resets the object to an empty state. 877 */ 878 static void 879 vm_object_terminate_pages(vm_object_t object) 880 { 881 vm_page_t p, p_next; 882 883 VM_OBJECT_ASSERT_WLOCKED(object); 884 885 /* 886 * Free any remaining pageable pages. This also removes them from the 887 * paging queues. However, don't free wired pages, just remove them 888 * from the object. Rather than incrementally removing each page from 889 * the object, the page and object are reset to any empty state. 890 */ 891 TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) { 892 vm_page_assert_unbusied(p); 893 KASSERT(p->object == object && 894 (p->ref_count & VPRC_OBJREF) != 0, 895 ("vm_object_terminate_pages: page %p is inconsistent", p)); 896 897 p->object = NULL; 898 if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) { 899 VM_CNT_INC(v_pfree); 900 vm_page_free(p); 901 } 902 } 903 904 /* 905 * If the object contained any pages, then reset it to an empty state. 906 * None of the object's fields, including "resident_page_count", were 907 * modified by the preceding loop. 908 */ 909 if (object->resident_page_count != 0) { 910 vm_radix_reclaim_allnodes(&object->rtree); 911 TAILQ_INIT(&object->memq); 912 object->resident_page_count = 0; 913 if (object->type == OBJT_VNODE) 914 vdrop(object->handle); 915 } 916 } 917 918 /* 919 * vm_object_terminate actually destroys the specified object, freeing 920 * up all previously used resources. 921 * 922 * The object must be locked. 923 * This routine may block. 924 */ 925 void 926 vm_object_terminate(vm_object_t object) 927 { 928 929 VM_OBJECT_ASSERT_WLOCKED(object); 930 KASSERT((object->flags & OBJ_DEAD) != 0, 931 ("terminating non-dead obj %p", object)); 932 KASSERT((object->flags & OBJ_COLLAPSING) == 0, 933 ("terminating collapsing obj %p", object)); 934 KASSERT(object->backing_object == NULL, 935 ("terminating shadow obj %p", object)); 936 937 /* 938 * Wait for the pageout daemon and other current users to be 939 * done with the object. Note that new paging_in_progress 940 * users can come after this wait, but they must check 941 * OBJ_DEAD flag set (without unlocking the object), and avoid 942 * the object being terminated. 943 */ 944 vm_object_pip_wait(object, "objtrm"); 945 946 KASSERT(object->ref_count == 0, 947 ("vm_object_terminate: object with references, ref_count=%d", 948 object->ref_count)); 949 950 if ((object->flags & OBJ_PG_DTOR) == 0) 951 vm_object_terminate_pages(object); 952 953 #if VM_NRESERVLEVEL > 0 954 if (__predict_false(!LIST_EMPTY(&object->rvq))) 955 vm_reserv_break_all(object); 956 #endif 957 958 KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT || 959 object->type == OBJT_SWAP, 960 ("%s: non-swap obj %p has cred", __func__, object)); 961 962 /* 963 * Let the pager know object is dead. 964 */ 965 vm_pager_deallocate(object); 966 VM_OBJECT_WUNLOCK(object); 967 968 vm_object_destroy(object); 969 } 970 971 /* 972 * Make the page read-only so that we can clear the object flags. However, if 973 * this is a nosync mmap then the object is likely to stay dirty so do not 974 * mess with the page and do not clear the object flags. Returns TRUE if the 975 * page should be flushed, and FALSE otherwise. 976 */ 977 static boolean_t 978 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean) 979 { 980 981 vm_page_assert_busied(p); 982 983 /* 984 * If we have been asked to skip nosync pages and this is a 985 * nosync page, skip it. Note that the object flags were not 986 * cleared in this case so we do not have to set them. 987 */ 988 if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) { 989 *allclean = FALSE; 990 return (FALSE); 991 } else { 992 pmap_remove_write(p); 993 return (p->dirty != 0); 994 } 995 } 996 997 /* 998 * vm_object_page_clean 999 * 1000 * Clean all dirty pages in the specified range of object. Leaves page 1001 * on whatever queue it is currently on. If NOSYNC is set then do not 1002 * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC), 1003 * leaving the object dirty. 1004 * 1005 * For swap objects backing tmpfs regular files, do not flush anything, 1006 * but remove write protection on the mapped pages to update mtime through 1007 * mmaped writes. 1008 * 1009 * When stuffing pages asynchronously, allow clustering. XXX we need a 1010 * synchronous clustering mode implementation. 1011 * 1012 * Odd semantics: if start == end, we clean everything. 1013 * 1014 * The object must be locked. 1015 * 1016 * Returns FALSE if some page from the range was not written, as 1017 * reported by the pager, and TRUE otherwise. 1018 */ 1019 boolean_t 1020 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end, 1021 int flags) 1022 { 1023 vm_page_t np, p; 1024 vm_pindex_t pi, tend, tstart; 1025 int curgeneration, n, pagerflags; 1026 boolean_t eio, res, allclean; 1027 1028 VM_OBJECT_ASSERT_WLOCKED(object); 1029 1030 if (!vm_object_mightbedirty(object) || object->resident_page_count == 0) 1031 return (TRUE); 1032 1033 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ? 1034 VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 1035 pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0; 1036 1037 tstart = OFF_TO_IDX(start); 1038 tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK); 1039 allclean = tstart == 0 && tend >= object->size; 1040 res = TRUE; 1041 1042 rescan: 1043 curgeneration = object->generation; 1044 1045 for (p = vm_page_find_least(object, tstart); p != NULL; p = np) { 1046 pi = p->pindex; 1047 if (pi >= tend) 1048 break; 1049 np = TAILQ_NEXT(p, listq); 1050 if (vm_page_none_valid(p)) 1051 continue; 1052 if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) { 1053 if (object->generation != curgeneration && 1054 (flags & OBJPC_SYNC) != 0) 1055 goto rescan; 1056 np = vm_page_find_least(object, pi); 1057 continue; 1058 } 1059 if (!vm_object_page_remove_write(p, flags, &allclean)) { 1060 vm_page_xunbusy(p); 1061 continue; 1062 } 1063 if (object->type == OBJT_VNODE) { 1064 n = vm_object_page_collect_flush(object, p, pagerflags, 1065 flags, &allclean, &eio); 1066 if (eio) { 1067 res = FALSE; 1068 allclean = FALSE; 1069 } 1070 if (object->generation != curgeneration && 1071 (flags & OBJPC_SYNC) != 0) 1072 goto rescan; 1073 1074 /* 1075 * If the VOP_PUTPAGES() did a truncated write, so 1076 * that even the first page of the run is not fully 1077 * written, vm_pageout_flush() returns 0 as the run 1078 * length. Since the condition that caused truncated 1079 * write may be permanent, e.g. exhausted free space, 1080 * accepting n == 0 would cause an infinite loop. 1081 * 1082 * Forwarding the iterator leaves the unwritten page 1083 * behind, but there is not much we can do there if 1084 * filesystem refuses to write it. 1085 */ 1086 if (n == 0) { 1087 n = 1; 1088 allclean = FALSE; 1089 } 1090 } else { 1091 n = 1; 1092 vm_page_xunbusy(p); 1093 } 1094 np = vm_page_find_least(object, pi + n); 1095 } 1096 #if 0 1097 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0); 1098 #endif 1099 1100 /* 1101 * Leave updating cleangeneration for tmpfs objects to tmpfs 1102 * scan. It needs to update mtime, which happens for other 1103 * filesystems during page writeouts. 1104 */ 1105 if (allclean && object->type == OBJT_VNODE) 1106 object->cleangeneration = curgeneration; 1107 return (res); 1108 } 1109 1110 static int 1111 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, 1112 int flags, boolean_t *allclean, boolean_t *eio) 1113 { 1114 vm_page_t ma[vm_pageout_page_count], p_first, tp; 1115 int count, i, mreq, runlen; 1116 1117 vm_page_lock_assert(p, MA_NOTOWNED); 1118 vm_page_assert_xbusied(p); 1119 VM_OBJECT_ASSERT_WLOCKED(object); 1120 1121 count = 1; 1122 mreq = 0; 1123 1124 for (tp = p; count < vm_pageout_page_count; count++) { 1125 tp = vm_page_next(tp); 1126 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1127 break; 1128 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1129 vm_page_xunbusy(tp); 1130 break; 1131 } 1132 } 1133 1134 for (p_first = p; count < vm_pageout_page_count; count++) { 1135 tp = vm_page_prev(p_first); 1136 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1137 break; 1138 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1139 vm_page_xunbusy(tp); 1140 break; 1141 } 1142 p_first = tp; 1143 mreq++; 1144 } 1145 1146 for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++) 1147 ma[i] = tp; 1148 1149 vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio); 1150 return (runlen); 1151 } 1152 1153 /* 1154 * Note that there is absolutely no sense in writing out 1155 * anonymous objects, so we track down the vnode object 1156 * to write out. 1157 * We invalidate (remove) all pages from the address space 1158 * for semantic correctness. 1159 * 1160 * If the backing object is a device object with unmanaged pages, then any 1161 * mappings to the specified range of pages must be removed before this 1162 * function is called. 1163 * 1164 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1165 * may start out with a NULL object. 1166 */ 1167 boolean_t 1168 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1169 boolean_t syncio, boolean_t invalidate) 1170 { 1171 vm_object_t backing_object; 1172 struct vnode *vp; 1173 struct mount *mp; 1174 int error, flags, fsync_after; 1175 boolean_t res; 1176 1177 if (object == NULL) 1178 return (TRUE); 1179 res = TRUE; 1180 error = 0; 1181 VM_OBJECT_WLOCK(object); 1182 while ((backing_object = object->backing_object) != NULL) { 1183 VM_OBJECT_WLOCK(backing_object); 1184 offset += object->backing_object_offset; 1185 VM_OBJECT_WUNLOCK(object); 1186 object = backing_object; 1187 if (object->size < OFF_TO_IDX(offset + size)) 1188 size = IDX_TO_OFF(object->size) - offset; 1189 } 1190 /* 1191 * Flush pages if writing is allowed, invalidate them 1192 * if invalidation requested. Pages undergoing I/O 1193 * will be ignored by vm_object_page_remove(). 1194 * 1195 * We cannot lock the vnode and then wait for paging 1196 * to complete without deadlocking against vm_fault. 1197 * Instead we simply call vm_object_page_remove() and 1198 * allow it to block internally on a page-by-page 1199 * basis when it encounters pages undergoing async 1200 * I/O. 1201 */ 1202 if (object->type == OBJT_VNODE && 1203 vm_object_mightbedirty(object) != 0 && 1204 ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) { 1205 VM_OBJECT_WUNLOCK(object); 1206 (void) vn_start_write(vp, &mp, V_WAIT); 1207 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1208 if (syncio && !invalidate && offset == 0 && 1209 atop(size) == object->size) { 1210 /* 1211 * If syncing the whole mapping of the file, 1212 * it is faster to schedule all the writes in 1213 * async mode, also allowing the clustering, 1214 * and then wait for i/o to complete. 1215 */ 1216 flags = 0; 1217 fsync_after = TRUE; 1218 } else { 1219 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1220 flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0; 1221 fsync_after = FALSE; 1222 } 1223 VM_OBJECT_WLOCK(object); 1224 res = vm_object_page_clean(object, offset, offset + size, 1225 flags); 1226 VM_OBJECT_WUNLOCK(object); 1227 if (fsync_after) 1228 error = VOP_FSYNC(vp, MNT_WAIT, curthread); 1229 VOP_UNLOCK(vp); 1230 vn_finished_write(mp); 1231 if (error != 0) 1232 res = FALSE; 1233 VM_OBJECT_WLOCK(object); 1234 } 1235 if ((object->type == OBJT_VNODE || 1236 object->type == OBJT_DEVICE) && invalidate) { 1237 if (object->type == OBJT_DEVICE) 1238 /* 1239 * The option OBJPR_NOTMAPPED must be passed here 1240 * because vm_object_page_remove() cannot remove 1241 * unmanaged mappings. 1242 */ 1243 flags = OBJPR_NOTMAPPED; 1244 else if (old_msync) 1245 flags = 0; 1246 else 1247 flags = OBJPR_CLEANONLY; 1248 vm_object_page_remove(object, OFF_TO_IDX(offset), 1249 OFF_TO_IDX(offset + size + PAGE_MASK), flags); 1250 } 1251 VM_OBJECT_WUNLOCK(object); 1252 return (res); 1253 } 1254 1255 /* 1256 * Determine whether the given advice can be applied to the object. Advice is 1257 * not applied to unmanaged pages since they never belong to page queues, and 1258 * since MADV_FREE is destructive, it can apply only to anonymous pages that 1259 * have been mapped at most once. 1260 */ 1261 static bool 1262 vm_object_advice_applies(vm_object_t object, int advice) 1263 { 1264 1265 if ((object->flags & OBJ_UNMANAGED) != 0) 1266 return (false); 1267 if (advice != MADV_FREE) 1268 return (true); 1269 return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) == 1270 (OBJ_ONEMAPPING | OBJ_ANON)); 1271 } 1272 1273 static void 1274 vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex, 1275 vm_size_t size) 1276 { 1277 1278 if (advice == MADV_FREE && object->type == OBJT_SWAP) 1279 swap_pager_freespace(object, pindex, size); 1280 } 1281 1282 /* 1283 * vm_object_madvise: 1284 * 1285 * Implements the madvise function at the object/page level. 1286 * 1287 * MADV_WILLNEED (any object) 1288 * 1289 * Activate the specified pages if they are resident. 1290 * 1291 * MADV_DONTNEED (any object) 1292 * 1293 * Deactivate the specified pages if they are resident. 1294 * 1295 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1296 * OBJ_ONEMAPPING only) 1297 * 1298 * Deactivate and clean the specified pages if they are 1299 * resident. This permits the process to reuse the pages 1300 * without faulting or the kernel to reclaim the pages 1301 * without I/O. 1302 */ 1303 void 1304 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end, 1305 int advice) 1306 { 1307 vm_pindex_t tpindex; 1308 vm_object_t backing_object, tobject; 1309 vm_page_t m, tm; 1310 1311 if (object == NULL) 1312 return; 1313 1314 relookup: 1315 VM_OBJECT_WLOCK(object); 1316 if (!vm_object_advice_applies(object, advice)) { 1317 VM_OBJECT_WUNLOCK(object); 1318 return; 1319 } 1320 for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) { 1321 tobject = object; 1322 1323 /* 1324 * If the next page isn't resident in the top-level object, we 1325 * need to search the shadow chain. When applying MADV_FREE, we 1326 * take care to release any swap space used to store 1327 * non-resident pages. 1328 */ 1329 if (m == NULL || pindex < m->pindex) { 1330 /* 1331 * Optimize a common case: if the top-level object has 1332 * no backing object, we can skip over the non-resident 1333 * range in constant time. 1334 */ 1335 if (object->backing_object == NULL) { 1336 tpindex = (m != NULL && m->pindex < end) ? 1337 m->pindex : end; 1338 vm_object_madvise_freespace(object, advice, 1339 pindex, tpindex - pindex); 1340 if ((pindex = tpindex) == end) 1341 break; 1342 goto next_page; 1343 } 1344 1345 tpindex = pindex; 1346 do { 1347 vm_object_madvise_freespace(tobject, advice, 1348 tpindex, 1); 1349 /* 1350 * Prepare to search the next object in the 1351 * chain. 1352 */ 1353 backing_object = tobject->backing_object; 1354 if (backing_object == NULL) 1355 goto next_pindex; 1356 VM_OBJECT_WLOCK(backing_object); 1357 tpindex += 1358 OFF_TO_IDX(tobject->backing_object_offset); 1359 if (tobject != object) 1360 VM_OBJECT_WUNLOCK(tobject); 1361 tobject = backing_object; 1362 if (!vm_object_advice_applies(tobject, advice)) 1363 goto next_pindex; 1364 } while ((tm = vm_page_lookup(tobject, tpindex)) == 1365 NULL); 1366 } else { 1367 next_page: 1368 tm = m; 1369 m = TAILQ_NEXT(m, listq); 1370 } 1371 1372 /* 1373 * If the page is not in a normal state, skip it. The page 1374 * can not be invalidated while the object lock is held. 1375 */ 1376 if (!vm_page_all_valid(tm) || vm_page_wired(tm)) 1377 goto next_pindex; 1378 KASSERT((tm->flags & PG_FICTITIOUS) == 0, 1379 ("vm_object_madvise: page %p is fictitious", tm)); 1380 KASSERT((tm->oflags & VPO_UNMANAGED) == 0, 1381 ("vm_object_madvise: page %p is not managed", tm)); 1382 if (vm_page_tryxbusy(tm) == 0) { 1383 if (object != tobject) 1384 VM_OBJECT_WUNLOCK(object); 1385 if (advice == MADV_WILLNEED) { 1386 /* 1387 * Reference the page before unlocking and 1388 * sleeping so that the page daemon is less 1389 * likely to reclaim it. 1390 */ 1391 vm_page_aflag_set(tm, PGA_REFERENCED); 1392 } 1393 vm_page_busy_sleep(tm, "madvpo", false); 1394 goto relookup; 1395 } 1396 vm_page_advise(tm, advice); 1397 vm_page_xunbusy(tm); 1398 vm_object_madvise_freespace(tobject, advice, tm->pindex, 1); 1399 next_pindex: 1400 if (tobject != object) 1401 VM_OBJECT_WUNLOCK(tobject); 1402 } 1403 VM_OBJECT_WUNLOCK(object); 1404 } 1405 1406 /* 1407 * vm_object_shadow: 1408 * 1409 * Create a new object which is backed by the 1410 * specified existing object range. The source 1411 * object reference is deallocated. 1412 * 1413 * The new object and offset into that object 1414 * are returned in the source parameters. 1415 */ 1416 void 1417 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length, 1418 struct ucred *cred, bool shared) 1419 { 1420 vm_object_t source; 1421 vm_object_t result; 1422 1423 source = *object; 1424 1425 /* 1426 * Don't create the new object if the old object isn't shared. 1427 * 1428 * If we hold the only reference we can guarantee that it won't 1429 * increase while we have the map locked. Otherwise the race is 1430 * harmless and we will end up with an extra shadow object that 1431 * will be collapsed later. 1432 */ 1433 if (source != NULL && source->ref_count == 1 && 1434 (source->flags & OBJ_ANON) != 0) 1435 return; 1436 1437 /* 1438 * Allocate a new object with the given length. 1439 */ 1440 result = vm_object_allocate_anon(atop(length), source, cred, length); 1441 1442 /* 1443 * Store the offset into the source object, and fix up the offset into 1444 * the new object. 1445 */ 1446 result->backing_object_offset = *offset; 1447 1448 if (shared || source != NULL) { 1449 VM_OBJECT_WLOCK(result); 1450 1451 /* 1452 * The new object shadows the source object, adding a 1453 * reference to it. Our caller changes his reference 1454 * to point to the new object, removing a reference to 1455 * the source object. Net result: no change of 1456 * reference count, unless the caller needs to add one 1457 * more reference due to forking a shared map entry. 1458 */ 1459 if (shared) { 1460 vm_object_reference_locked(result); 1461 vm_object_clear_flag(result, OBJ_ONEMAPPING); 1462 } 1463 1464 /* 1465 * Try to optimize the result object's page color when 1466 * shadowing in order to maintain page coloring 1467 * consistency in the combined shadowed object. 1468 */ 1469 if (source != NULL) { 1470 vm_object_backing_insert(result, source); 1471 result->domain = source->domain; 1472 #if VM_NRESERVLEVEL > 0 1473 result->flags |= source->flags & OBJ_COLORED; 1474 result->pg_color = (source->pg_color + 1475 OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER - 1476 1)) - 1); 1477 #endif 1478 } 1479 VM_OBJECT_WUNLOCK(result); 1480 } 1481 1482 /* 1483 * Return the new things 1484 */ 1485 *offset = 0; 1486 *object = result; 1487 } 1488 1489 /* 1490 * vm_object_split: 1491 * 1492 * Split the pages in a map entry into a new object. This affords 1493 * easier removal of unused pages, and keeps object inheritance from 1494 * being a negative impact on memory usage. 1495 */ 1496 void 1497 vm_object_split(vm_map_entry_t entry) 1498 { 1499 vm_page_t m, m_busy, m_next; 1500 vm_object_t orig_object, new_object, backing_object; 1501 vm_pindex_t idx, offidxstart; 1502 vm_size_t size; 1503 1504 orig_object = entry->object.vm_object; 1505 KASSERT((orig_object->flags & OBJ_ONEMAPPING) != 0, 1506 ("vm_object_split: Splitting object with multiple mappings.")); 1507 if ((orig_object->flags & OBJ_ANON) == 0) 1508 return; 1509 if (orig_object->ref_count <= 1) 1510 return; 1511 VM_OBJECT_WUNLOCK(orig_object); 1512 1513 offidxstart = OFF_TO_IDX(entry->offset); 1514 size = atop(entry->end - entry->start); 1515 1516 /* 1517 * If swap_pager_copy() is later called, it will convert new_object 1518 * into a swap object. 1519 */ 1520 new_object = vm_object_allocate_anon(size, orig_object, 1521 orig_object->cred, ptoa(size)); 1522 1523 /* 1524 * We must wait for the orig_object to complete any in-progress 1525 * collapse so that the swap blocks are stable below. The 1526 * additional reference on backing_object by new object will 1527 * prevent further collapse operations until split completes. 1528 */ 1529 VM_OBJECT_WLOCK(orig_object); 1530 vm_object_collapse_wait(orig_object); 1531 1532 /* 1533 * At this point, the new object is still private, so the order in 1534 * which the original and new objects are locked does not matter. 1535 */ 1536 VM_OBJECT_WLOCK(new_object); 1537 new_object->domain = orig_object->domain; 1538 backing_object = orig_object->backing_object; 1539 if (backing_object != NULL) { 1540 vm_object_backing_insert_ref(new_object, backing_object); 1541 new_object->backing_object_offset = 1542 orig_object->backing_object_offset + entry->offset; 1543 } 1544 if (orig_object->cred != NULL) { 1545 crhold(orig_object->cred); 1546 KASSERT(orig_object->charge >= ptoa(size), 1547 ("orig_object->charge < 0")); 1548 orig_object->charge -= ptoa(size); 1549 } 1550 1551 /* 1552 * Mark the split operation so that swap_pager_getpages() knows 1553 * that the object is in transition. 1554 */ 1555 vm_object_set_flag(orig_object, OBJ_SPLIT); 1556 m_busy = NULL; 1557 #ifdef INVARIANTS 1558 idx = 0; 1559 #endif 1560 retry: 1561 m = vm_page_find_least(orig_object, offidxstart); 1562 KASSERT(m == NULL || idx <= m->pindex - offidxstart, 1563 ("%s: object %p was repopulated", __func__, orig_object)); 1564 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1565 m = m_next) { 1566 m_next = TAILQ_NEXT(m, listq); 1567 1568 /* 1569 * We must wait for pending I/O to complete before we can 1570 * rename the page. 1571 * 1572 * We do not have to VM_PROT_NONE the page as mappings should 1573 * not be changed by this operation. 1574 */ 1575 if (vm_page_tryxbusy(m) == 0) { 1576 VM_OBJECT_WUNLOCK(new_object); 1577 vm_page_sleep_if_busy(m, "spltwt"); 1578 VM_OBJECT_WLOCK(new_object); 1579 goto retry; 1580 } 1581 1582 /* 1583 * The page was left invalid. Likely placed there by 1584 * an incomplete fault. Just remove and ignore. 1585 */ 1586 if (vm_page_none_valid(m)) { 1587 if (vm_page_remove(m)) 1588 vm_page_free(m); 1589 continue; 1590 } 1591 1592 /* vm_page_rename() will dirty the page. */ 1593 if (vm_page_rename(m, new_object, idx)) { 1594 vm_page_xunbusy(m); 1595 VM_OBJECT_WUNLOCK(new_object); 1596 VM_OBJECT_WUNLOCK(orig_object); 1597 vm_radix_wait(); 1598 VM_OBJECT_WLOCK(orig_object); 1599 VM_OBJECT_WLOCK(new_object); 1600 goto retry; 1601 } 1602 1603 #if VM_NRESERVLEVEL > 0 1604 /* 1605 * If some of the reservation's allocated pages remain with 1606 * the original object, then transferring the reservation to 1607 * the new object is neither particularly beneficial nor 1608 * particularly harmful as compared to leaving the reservation 1609 * with the original object. If, however, all of the 1610 * reservation's allocated pages are transferred to the new 1611 * object, then transferring the reservation is typically 1612 * beneficial. Determining which of these two cases applies 1613 * would be more costly than unconditionally renaming the 1614 * reservation. 1615 */ 1616 vm_reserv_rename(m, new_object, orig_object, offidxstart); 1617 #endif 1618 1619 /* 1620 * orig_object's type may change while sleeping, so keep track 1621 * of the beginning of the busied range. 1622 */ 1623 if (orig_object->type != OBJT_SWAP) 1624 vm_page_xunbusy(m); 1625 else if (m_busy == NULL) 1626 m_busy = m; 1627 } 1628 if (orig_object->type == OBJT_SWAP) { 1629 /* 1630 * swap_pager_copy() can sleep, in which case the orig_object's 1631 * and new_object's locks are released and reacquired. 1632 */ 1633 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1634 if (m_busy != NULL) 1635 TAILQ_FOREACH_FROM(m_busy, &new_object->memq, listq) 1636 vm_page_xunbusy(m_busy); 1637 } 1638 vm_object_clear_flag(orig_object, OBJ_SPLIT); 1639 VM_OBJECT_WUNLOCK(orig_object); 1640 VM_OBJECT_WUNLOCK(new_object); 1641 entry->object.vm_object = new_object; 1642 entry->offset = 0LL; 1643 vm_object_deallocate(orig_object); 1644 VM_OBJECT_WLOCK(new_object); 1645 } 1646 1647 static vm_page_t 1648 vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p) 1649 { 1650 vm_object_t backing_object; 1651 1652 VM_OBJECT_ASSERT_WLOCKED(object); 1653 backing_object = object->backing_object; 1654 VM_OBJECT_ASSERT_WLOCKED(backing_object); 1655 1656 KASSERT(p == NULL || p->object == object || p->object == backing_object, 1657 ("invalid ownership %p %p %p", p, object, backing_object)); 1658 /* The page is only NULL when rename fails. */ 1659 if (p == NULL) { 1660 VM_OBJECT_WUNLOCK(object); 1661 VM_OBJECT_WUNLOCK(backing_object); 1662 vm_radix_wait(); 1663 } else { 1664 if (p->object == object) 1665 VM_OBJECT_WUNLOCK(backing_object); 1666 else 1667 VM_OBJECT_WUNLOCK(object); 1668 vm_page_busy_sleep(p, "vmocol", false); 1669 } 1670 VM_OBJECT_WLOCK(object); 1671 VM_OBJECT_WLOCK(backing_object); 1672 return (TAILQ_FIRST(&backing_object->memq)); 1673 } 1674 1675 static bool 1676 vm_object_scan_all_shadowed(vm_object_t object) 1677 { 1678 vm_object_t backing_object; 1679 vm_page_t p, pp; 1680 vm_pindex_t backing_offset_index, new_pindex, pi, ps; 1681 1682 VM_OBJECT_ASSERT_WLOCKED(object); 1683 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1684 1685 backing_object = object->backing_object; 1686 1687 if ((backing_object->flags & OBJ_ANON) == 0) 1688 return (false); 1689 1690 pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1691 p = vm_page_find_least(backing_object, pi); 1692 ps = swap_pager_find_least(backing_object, pi); 1693 1694 /* 1695 * Only check pages inside the parent object's range and 1696 * inside the parent object's mapping of the backing object. 1697 */ 1698 for (;; pi++) { 1699 if (p != NULL && p->pindex < pi) 1700 p = TAILQ_NEXT(p, listq); 1701 if (ps < pi) 1702 ps = swap_pager_find_least(backing_object, pi); 1703 if (p == NULL && ps >= backing_object->size) 1704 break; 1705 else if (p == NULL) 1706 pi = ps; 1707 else 1708 pi = MIN(p->pindex, ps); 1709 1710 new_pindex = pi - backing_offset_index; 1711 if (new_pindex >= object->size) 1712 break; 1713 1714 if (p != NULL) { 1715 /* 1716 * If the backing object page is busy a 1717 * grandparent or older page may still be 1718 * undergoing CoW. It is not safe to collapse 1719 * the backing object until it is quiesced. 1720 */ 1721 if (vm_page_tryxbusy(p) == 0) 1722 return (false); 1723 1724 /* 1725 * We raced with the fault handler that left 1726 * newly allocated invalid page on the object 1727 * queue and retried. 1728 */ 1729 if (!vm_page_all_valid(p)) 1730 goto unbusy_ret; 1731 } 1732 1733 /* 1734 * See if the parent has the page or if the parent's object 1735 * pager has the page. If the parent has the page but the page 1736 * is not valid, the parent's object pager must have the page. 1737 * 1738 * If this fails, the parent does not completely shadow the 1739 * object and we might as well give up now. 1740 */ 1741 pp = vm_page_lookup(object, new_pindex); 1742 1743 /* 1744 * The valid check here is stable due to object lock 1745 * being required to clear valid and initiate paging. 1746 * Busy of p disallows fault handler to validate pp. 1747 */ 1748 if ((pp == NULL || vm_page_none_valid(pp)) && 1749 !vm_pager_has_page(object, new_pindex, NULL, NULL)) 1750 goto unbusy_ret; 1751 if (p != NULL) 1752 vm_page_xunbusy(p); 1753 } 1754 return (true); 1755 1756 unbusy_ret: 1757 if (p != NULL) 1758 vm_page_xunbusy(p); 1759 return (false); 1760 } 1761 1762 static void 1763 vm_object_collapse_scan(vm_object_t object) 1764 { 1765 vm_object_t backing_object; 1766 vm_page_t next, p, pp; 1767 vm_pindex_t backing_offset_index, new_pindex; 1768 1769 VM_OBJECT_ASSERT_WLOCKED(object); 1770 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1771 1772 backing_object = object->backing_object; 1773 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1774 1775 /* 1776 * Our scan 1777 */ 1778 for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) { 1779 next = TAILQ_NEXT(p, listq); 1780 new_pindex = p->pindex - backing_offset_index; 1781 1782 /* 1783 * Check for busy page 1784 */ 1785 if (vm_page_tryxbusy(p) == 0) { 1786 next = vm_object_collapse_scan_wait(object, p); 1787 continue; 1788 } 1789 1790 KASSERT(object->backing_object == backing_object, 1791 ("vm_object_collapse_scan: backing object mismatch %p != %p", 1792 object->backing_object, backing_object)); 1793 KASSERT(p->object == backing_object, 1794 ("vm_object_collapse_scan: object mismatch %p != %p", 1795 p->object, backing_object)); 1796 1797 if (p->pindex < backing_offset_index || 1798 new_pindex >= object->size) { 1799 if (backing_object->type == OBJT_SWAP) 1800 swap_pager_freespace(backing_object, p->pindex, 1801 1); 1802 1803 KASSERT(!pmap_page_is_mapped(p), 1804 ("freeing mapped page %p", p)); 1805 if (vm_page_remove(p)) 1806 vm_page_free(p); 1807 continue; 1808 } 1809 1810 if (!vm_page_all_valid(p)) { 1811 KASSERT(!pmap_page_is_mapped(p), 1812 ("freeing mapped page %p", p)); 1813 if (vm_page_remove(p)) 1814 vm_page_free(p); 1815 continue; 1816 } 1817 1818 pp = vm_page_lookup(object, new_pindex); 1819 if (pp != NULL && vm_page_tryxbusy(pp) == 0) { 1820 vm_page_xunbusy(p); 1821 /* 1822 * The page in the parent is busy and possibly not 1823 * (yet) valid. Until its state is finalized by the 1824 * busy bit owner, we can't tell whether it shadows the 1825 * original page. 1826 */ 1827 next = vm_object_collapse_scan_wait(object, pp); 1828 continue; 1829 } 1830 1831 if (pp != NULL && vm_page_none_valid(pp)) { 1832 /* 1833 * The page was invalid in the parent. Likely placed 1834 * there by an incomplete fault. Just remove and 1835 * ignore. p can replace it. 1836 */ 1837 if (vm_page_remove(pp)) 1838 vm_page_free(pp); 1839 pp = NULL; 1840 } 1841 1842 if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL, 1843 NULL)) { 1844 /* 1845 * The page already exists in the parent OR swap exists 1846 * for this location in the parent. Leave the parent's 1847 * page alone. Destroy the original page from the 1848 * backing object. 1849 */ 1850 if (backing_object->type == OBJT_SWAP) 1851 swap_pager_freespace(backing_object, p->pindex, 1852 1); 1853 KASSERT(!pmap_page_is_mapped(p), 1854 ("freeing mapped page %p", p)); 1855 if (vm_page_remove(p)) 1856 vm_page_free(p); 1857 if (pp != NULL) 1858 vm_page_xunbusy(pp); 1859 continue; 1860 } 1861 1862 /* 1863 * Page does not exist in parent, rename the page from the 1864 * backing object to the main object. 1865 * 1866 * If the page was mapped to a process, it can remain mapped 1867 * through the rename. vm_page_rename() will dirty the page. 1868 */ 1869 if (vm_page_rename(p, object, new_pindex)) { 1870 vm_page_xunbusy(p); 1871 next = vm_object_collapse_scan_wait(object, NULL); 1872 continue; 1873 } 1874 1875 /* Use the old pindex to free the right page. */ 1876 if (backing_object->type == OBJT_SWAP) 1877 swap_pager_freespace(backing_object, 1878 new_pindex + backing_offset_index, 1); 1879 1880 #if VM_NRESERVLEVEL > 0 1881 /* 1882 * Rename the reservation. 1883 */ 1884 vm_reserv_rename(p, object, backing_object, 1885 backing_offset_index); 1886 #endif 1887 vm_page_xunbusy(p); 1888 } 1889 return; 1890 } 1891 1892 /* 1893 * vm_object_collapse: 1894 * 1895 * Collapse an object with the object backing it. 1896 * Pages in the backing object are moved into the 1897 * parent, and the backing object is deallocated. 1898 */ 1899 void 1900 vm_object_collapse(vm_object_t object) 1901 { 1902 vm_object_t backing_object, new_backing_object; 1903 1904 VM_OBJECT_ASSERT_WLOCKED(object); 1905 1906 while (TRUE) { 1907 KASSERT((object->flags & (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON, 1908 ("collapsing invalid object")); 1909 1910 /* 1911 * Wait for the backing_object to finish any pending 1912 * collapse so that the caller sees the shortest possible 1913 * shadow chain. 1914 */ 1915 backing_object = vm_object_backing_collapse_wait(object); 1916 if (backing_object == NULL) 1917 return; 1918 1919 KASSERT(object->ref_count > 0 && 1920 object->ref_count > object->shadow_count, 1921 ("collapse with invalid ref %d or shadow %d count.", 1922 object->ref_count, object->shadow_count)); 1923 KASSERT((backing_object->flags & 1924 (OBJ_COLLAPSING | OBJ_DEAD)) == 0, 1925 ("vm_object_collapse: Backing object already collapsing.")); 1926 KASSERT((object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0, 1927 ("vm_object_collapse: object is already collapsing.")); 1928 1929 /* 1930 * We know that we can either collapse the backing object if 1931 * the parent is the only reference to it, or (perhaps) have 1932 * the parent bypass the object if the parent happens to shadow 1933 * all the resident pages in the entire backing object. 1934 */ 1935 if (backing_object->ref_count == 1) { 1936 KASSERT(backing_object->shadow_count == 1, 1937 ("vm_object_collapse: shadow_count: %d", 1938 backing_object->shadow_count)); 1939 vm_object_pip_add(object, 1); 1940 vm_object_set_flag(object, OBJ_COLLAPSING); 1941 vm_object_pip_add(backing_object, 1); 1942 vm_object_set_flag(backing_object, OBJ_DEAD); 1943 1944 /* 1945 * If there is exactly one reference to the backing 1946 * object, we can collapse it into the parent. 1947 */ 1948 vm_object_collapse_scan(object); 1949 1950 #if VM_NRESERVLEVEL > 0 1951 /* 1952 * Break any reservations from backing_object. 1953 */ 1954 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1955 vm_reserv_break_all(backing_object); 1956 #endif 1957 1958 /* 1959 * Move the pager from backing_object to object. 1960 */ 1961 if (backing_object->type == OBJT_SWAP) { 1962 /* 1963 * swap_pager_copy() can sleep, in which case 1964 * the backing_object's and object's locks are 1965 * released and reacquired. 1966 * Since swap_pager_copy() is being asked to 1967 * destroy backing_object, it will change the 1968 * type to OBJT_DEFAULT. 1969 */ 1970 swap_pager_copy( 1971 backing_object, 1972 object, 1973 OFF_TO_IDX(object->backing_object_offset), TRUE); 1974 } 1975 1976 /* 1977 * Object now shadows whatever backing_object did. 1978 */ 1979 vm_object_clear_flag(object, OBJ_COLLAPSING); 1980 vm_object_backing_transfer(object, backing_object); 1981 object->backing_object_offset += 1982 backing_object->backing_object_offset; 1983 VM_OBJECT_WUNLOCK(object); 1984 vm_object_pip_wakeup(object); 1985 1986 /* 1987 * Discard backing_object. 1988 * 1989 * Since the backing object has no pages, no pager left, 1990 * and no object references within it, all that is 1991 * necessary is to dispose of it. 1992 */ 1993 KASSERT(backing_object->ref_count == 1, ( 1994 "backing_object %p was somehow re-referenced during collapse!", 1995 backing_object)); 1996 vm_object_pip_wakeup(backing_object); 1997 (void)refcount_release(&backing_object->ref_count); 1998 vm_object_terminate(backing_object); 1999 counter_u64_add(object_collapses, 1); 2000 VM_OBJECT_WLOCK(object); 2001 } else { 2002 /* 2003 * If we do not entirely shadow the backing object, 2004 * there is nothing we can do so we give up. 2005 * 2006 * The object lock and backing_object lock must not 2007 * be dropped during this sequence. 2008 */ 2009 if (!vm_object_scan_all_shadowed(object)) { 2010 VM_OBJECT_WUNLOCK(backing_object); 2011 break; 2012 } 2013 2014 /* 2015 * Make the parent shadow the next object in the 2016 * chain. Deallocating backing_object will not remove 2017 * it, since its reference count is at least 2. 2018 */ 2019 vm_object_backing_remove_locked(object); 2020 new_backing_object = backing_object->backing_object; 2021 if (new_backing_object != NULL) { 2022 vm_object_backing_insert_ref(object, 2023 new_backing_object); 2024 object->backing_object_offset += 2025 backing_object->backing_object_offset; 2026 } 2027 2028 /* 2029 * Drop the reference count on backing_object. Since 2030 * its ref_count was at least 2, it will not vanish. 2031 */ 2032 (void)refcount_release(&backing_object->ref_count); 2033 KASSERT(backing_object->ref_count >= 1, ( 2034 "backing_object %p was somehow dereferenced during collapse!", 2035 backing_object)); 2036 VM_OBJECT_WUNLOCK(backing_object); 2037 counter_u64_add(object_bypasses, 1); 2038 } 2039 2040 /* 2041 * Try again with this object's new backing object. 2042 */ 2043 } 2044 } 2045 2046 /* 2047 * vm_object_page_remove: 2048 * 2049 * For the given object, either frees or invalidates each of the 2050 * specified pages. In general, a page is freed. However, if a page is 2051 * wired for any reason other than the existence of a managed, wired 2052 * mapping, then it may be invalidated but not removed from the object. 2053 * Pages are specified by the given range ["start", "end") and the option 2054 * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range 2055 * extends from "start" to the end of the object. If the option 2056 * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the 2057 * specified range are affected. If the option OBJPR_NOTMAPPED is 2058 * specified, then the pages within the specified range must have no 2059 * mappings. Otherwise, if this option is not specified, any mappings to 2060 * the specified pages are removed before the pages are freed or 2061 * invalidated. 2062 * 2063 * In general, this operation should only be performed on objects that 2064 * contain managed pages. There are, however, two exceptions. First, it 2065 * is performed on the kernel and kmem objects by vm_map_entry_delete(). 2066 * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device- 2067 * backed pages. In both of these cases, the option OBJPR_CLEANONLY must 2068 * not be specified and the option OBJPR_NOTMAPPED must be specified. 2069 * 2070 * The object must be locked. 2071 */ 2072 void 2073 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 2074 int options) 2075 { 2076 vm_page_t p, next; 2077 2078 VM_OBJECT_ASSERT_WLOCKED(object); 2079 KASSERT((object->flags & OBJ_UNMANAGED) == 0 || 2080 (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED, 2081 ("vm_object_page_remove: illegal options for object %p", object)); 2082 if (object->resident_page_count == 0) 2083 return; 2084 vm_object_pip_add(object, 1); 2085 again: 2086 p = vm_page_find_least(object, start); 2087 2088 /* 2089 * Here, the variable "p" is either (1) the page with the least pindex 2090 * greater than or equal to the parameter "start" or (2) NULL. 2091 */ 2092 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 2093 next = TAILQ_NEXT(p, listq); 2094 2095 /* 2096 * If the page is wired for any reason besides the existence 2097 * of managed, wired mappings, then it cannot be freed. For 2098 * example, fictitious pages, which represent device memory, 2099 * are inherently wired and cannot be freed. They can, 2100 * however, be invalidated if the option OBJPR_CLEANONLY is 2101 * not specified. 2102 */ 2103 if (vm_page_tryxbusy(p) == 0) { 2104 vm_page_sleep_if_busy(p, "vmopar"); 2105 goto again; 2106 } 2107 if (vm_page_wired(p)) { 2108 wired: 2109 if ((options & OBJPR_NOTMAPPED) == 0 && 2110 object->ref_count != 0) 2111 pmap_remove_all(p); 2112 if ((options & OBJPR_CLEANONLY) == 0) { 2113 vm_page_invalid(p); 2114 vm_page_undirty(p); 2115 } 2116 vm_page_xunbusy(p); 2117 continue; 2118 } 2119 KASSERT((p->flags & PG_FICTITIOUS) == 0, 2120 ("vm_object_page_remove: page %p is fictitious", p)); 2121 if ((options & OBJPR_CLEANONLY) != 0 && 2122 !vm_page_none_valid(p)) { 2123 if ((options & OBJPR_NOTMAPPED) == 0 && 2124 object->ref_count != 0 && 2125 !vm_page_try_remove_write(p)) 2126 goto wired; 2127 if (p->dirty != 0) { 2128 vm_page_xunbusy(p); 2129 continue; 2130 } 2131 } 2132 if ((options & OBJPR_NOTMAPPED) == 0 && 2133 object->ref_count != 0 && !vm_page_try_remove_all(p)) 2134 goto wired; 2135 vm_page_free(p); 2136 } 2137 vm_object_pip_wakeup(object); 2138 2139 if (object->type == OBJT_SWAP) { 2140 if (end == 0) 2141 end = object->size; 2142 swap_pager_freespace(object, start, end - start); 2143 } 2144 } 2145 2146 /* 2147 * vm_object_page_noreuse: 2148 * 2149 * For the given object, attempt to move the specified pages to 2150 * the head of the inactive queue. This bypasses regular LRU 2151 * operation and allows the pages to be reused quickly under memory 2152 * pressure. If a page is wired for any reason, then it will not 2153 * be queued. Pages are specified by the range ["start", "end"). 2154 * As a special case, if "end" is zero, then the range extends from 2155 * "start" to the end of the object. 2156 * 2157 * This operation should only be performed on objects that 2158 * contain non-fictitious, managed pages. 2159 * 2160 * The object must be locked. 2161 */ 2162 void 2163 vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2164 { 2165 vm_page_t p, next; 2166 2167 VM_OBJECT_ASSERT_LOCKED(object); 2168 KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0, 2169 ("vm_object_page_noreuse: illegal object %p", object)); 2170 if (object->resident_page_count == 0) 2171 return; 2172 p = vm_page_find_least(object, start); 2173 2174 /* 2175 * Here, the variable "p" is either (1) the page with the least pindex 2176 * greater than or equal to the parameter "start" or (2) NULL. 2177 */ 2178 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 2179 next = TAILQ_NEXT(p, listq); 2180 vm_page_deactivate_noreuse(p); 2181 } 2182 } 2183 2184 /* 2185 * Populate the specified range of the object with valid pages. Returns 2186 * TRUE if the range is successfully populated and FALSE otherwise. 2187 * 2188 * Note: This function should be optimized to pass a larger array of 2189 * pages to vm_pager_get_pages() before it is applied to a non- 2190 * OBJT_DEVICE object. 2191 * 2192 * The object must be locked. 2193 */ 2194 boolean_t 2195 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2196 { 2197 vm_page_t m; 2198 vm_pindex_t pindex; 2199 int rv; 2200 2201 VM_OBJECT_ASSERT_WLOCKED(object); 2202 for (pindex = start; pindex < end; pindex++) { 2203 rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL); 2204 if (rv != VM_PAGER_OK) 2205 break; 2206 2207 /* 2208 * Keep "m" busy because a subsequent iteration may unlock 2209 * the object. 2210 */ 2211 } 2212 if (pindex > start) { 2213 m = vm_page_lookup(object, start); 2214 while (m != NULL && m->pindex < pindex) { 2215 vm_page_xunbusy(m); 2216 m = TAILQ_NEXT(m, listq); 2217 } 2218 } 2219 return (pindex == end); 2220 } 2221 2222 /* 2223 * Routine: vm_object_coalesce 2224 * Function: Coalesces two objects backing up adjoining 2225 * regions of memory into a single object. 2226 * 2227 * returns TRUE if objects were combined. 2228 * 2229 * NOTE: Only works at the moment if the second object is NULL - 2230 * if it's not, which object do we lock first? 2231 * 2232 * Parameters: 2233 * prev_object First object to coalesce 2234 * prev_offset Offset into prev_object 2235 * prev_size Size of reference to prev_object 2236 * next_size Size of reference to the second object 2237 * reserved Indicator that extension region has 2238 * swap accounted for 2239 * 2240 * Conditions: 2241 * The object must *not* be locked. 2242 */ 2243 boolean_t 2244 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2245 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2246 { 2247 vm_pindex_t next_pindex; 2248 2249 if (prev_object == NULL) 2250 return (TRUE); 2251 if ((prev_object->flags & OBJ_ANON) == 0) 2252 return (FALSE); 2253 2254 VM_OBJECT_WLOCK(prev_object); 2255 /* 2256 * Try to collapse the object first. 2257 */ 2258 vm_object_collapse(prev_object); 2259 2260 /* 2261 * Can't coalesce if: . more than one reference . paged out . shadows 2262 * another object . has a copy elsewhere (any of which mean that the 2263 * pages not mapped to prev_entry may be in use anyway) 2264 */ 2265 if (prev_object->backing_object != NULL) { 2266 VM_OBJECT_WUNLOCK(prev_object); 2267 return (FALSE); 2268 } 2269 2270 prev_size >>= PAGE_SHIFT; 2271 next_size >>= PAGE_SHIFT; 2272 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2273 2274 if (prev_object->ref_count > 1 && 2275 prev_object->size != next_pindex && 2276 (prev_object->flags & OBJ_ONEMAPPING) == 0) { 2277 VM_OBJECT_WUNLOCK(prev_object); 2278 return (FALSE); 2279 } 2280 2281 /* 2282 * Account for the charge. 2283 */ 2284 if (prev_object->cred != NULL) { 2285 /* 2286 * If prev_object was charged, then this mapping, 2287 * although not charged now, may become writable 2288 * later. Non-NULL cred in the object would prevent 2289 * swap reservation during enabling of the write 2290 * access, so reserve swap now. Failed reservation 2291 * cause allocation of the separate object for the map 2292 * entry, and swap reservation for this entry is 2293 * managed in appropriate time. 2294 */ 2295 if (!reserved && !swap_reserve_by_cred(ptoa(next_size), 2296 prev_object->cred)) { 2297 VM_OBJECT_WUNLOCK(prev_object); 2298 return (FALSE); 2299 } 2300 prev_object->charge += ptoa(next_size); 2301 } 2302 2303 /* 2304 * Remove any pages that may still be in the object from a previous 2305 * deallocation. 2306 */ 2307 if (next_pindex < prev_object->size) { 2308 vm_object_page_remove(prev_object, next_pindex, next_pindex + 2309 next_size, 0); 2310 #if 0 2311 if (prev_object->cred != NULL) { 2312 KASSERT(prev_object->charge >= 2313 ptoa(prev_object->size - next_pindex), 2314 ("object %p overcharged 1 %jx %jx", prev_object, 2315 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2316 prev_object->charge -= ptoa(prev_object->size - 2317 next_pindex); 2318 } 2319 #endif 2320 } 2321 2322 /* 2323 * Extend the object if necessary. 2324 */ 2325 if (next_pindex + next_size > prev_object->size) 2326 prev_object->size = next_pindex + next_size; 2327 2328 VM_OBJECT_WUNLOCK(prev_object); 2329 return (TRUE); 2330 } 2331 2332 void 2333 vm_object_set_writeable_dirty(vm_object_t object) 2334 { 2335 2336 /* Only set for vnodes & tmpfs */ 2337 if (object->type != OBJT_VNODE && 2338 (object->flags & OBJ_TMPFS_NODE) == 0) 2339 return; 2340 atomic_add_int(&object->generation, 1); 2341 } 2342 2343 /* 2344 * vm_object_unwire: 2345 * 2346 * For each page offset within the specified range of the given object, 2347 * find the highest-level page in the shadow chain and unwire it. A page 2348 * must exist at every page offset, and the highest-level page must be 2349 * wired. 2350 */ 2351 void 2352 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length, 2353 uint8_t queue) 2354 { 2355 vm_object_t tobject, t1object; 2356 vm_page_t m, tm; 2357 vm_pindex_t end_pindex, pindex, tpindex; 2358 int depth, locked_depth; 2359 2360 KASSERT((offset & PAGE_MASK) == 0, 2361 ("vm_object_unwire: offset is not page aligned")); 2362 KASSERT((length & PAGE_MASK) == 0, 2363 ("vm_object_unwire: length is not a multiple of PAGE_SIZE")); 2364 /* The wired count of a fictitious page never changes. */ 2365 if ((object->flags & OBJ_FICTITIOUS) != 0) 2366 return; 2367 pindex = OFF_TO_IDX(offset); 2368 end_pindex = pindex + atop(length); 2369 again: 2370 locked_depth = 1; 2371 VM_OBJECT_RLOCK(object); 2372 m = vm_page_find_least(object, pindex); 2373 while (pindex < end_pindex) { 2374 if (m == NULL || pindex < m->pindex) { 2375 /* 2376 * The first object in the shadow chain doesn't 2377 * contain a page at the current index. Therefore, 2378 * the page must exist in a backing object. 2379 */ 2380 tobject = object; 2381 tpindex = pindex; 2382 depth = 0; 2383 do { 2384 tpindex += 2385 OFF_TO_IDX(tobject->backing_object_offset); 2386 tobject = tobject->backing_object; 2387 KASSERT(tobject != NULL, 2388 ("vm_object_unwire: missing page")); 2389 if ((tobject->flags & OBJ_FICTITIOUS) != 0) 2390 goto next_page; 2391 depth++; 2392 if (depth == locked_depth) { 2393 locked_depth++; 2394 VM_OBJECT_RLOCK(tobject); 2395 } 2396 } while ((tm = vm_page_lookup(tobject, tpindex)) == 2397 NULL); 2398 } else { 2399 tm = m; 2400 m = TAILQ_NEXT(m, listq); 2401 } 2402 if (vm_page_trysbusy(tm) == 0) { 2403 for (tobject = object; locked_depth >= 1; 2404 locked_depth--) { 2405 t1object = tobject->backing_object; 2406 if (tm->object != tobject) 2407 VM_OBJECT_RUNLOCK(tobject); 2408 tobject = t1object; 2409 } 2410 vm_page_busy_sleep(tm, "unwbo", true); 2411 goto again; 2412 } 2413 vm_page_unwire(tm, queue); 2414 vm_page_sunbusy(tm); 2415 next_page: 2416 pindex++; 2417 } 2418 /* Release the accumulated object locks. */ 2419 for (tobject = object; locked_depth >= 1; locked_depth--) { 2420 t1object = tobject->backing_object; 2421 VM_OBJECT_RUNLOCK(tobject); 2422 tobject = t1object; 2423 } 2424 } 2425 2426 /* 2427 * Return the vnode for the given object, or NULL if none exists. 2428 * For tmpfs objects, the function may return NULL if there is 2429 * no vnode allocated at the time of the call. 2430 */ 2431 struct vnode * 2432 vm_object_vnode(vm_object_t object) 2433 { 2434 struct vnode *vp; 2435 2436 VM_OBJECT_ASSERT_LOCKED(object); 2437 if (object->type == OBJT_VNODE) { 2438 vp = object->handle; 2439 KASSERT(vp != NULL, ("%s: OBJT_VNODE has no vnode", __func__)); 2440 } else if (object->type == OBJT_SWAP && 2441 (object->flags & OBJ_TMPFS) != 0) { 2442 vp = object->un_pager.swp.swp_tmpfs; 2443 KASSERT(vp != NULL, ("%s: OBJT_TMPFS has no vnode", __func__)); 2444 } else { 2445 vp = NULL; 2446 } 2447 return (vp); 2448 } 2449 2450 /* 2451 * Busy the vm object. This prevents new pages belonging to the object from 2452 * becoming busy. Existing pages persist as busy. Callers are responsible 2453 * for checking page state before proceeding. 2454 */ 2455 void 2456 vm_object_busy(vm_object_t obj) 2457 { 2458 2459 VM_OBJECT_ASSERT_LOCKED(obj); 2460 2461 blockcount_acquire(&obj->busy, 1); 2462 /* The fence is required to order loads of page busy. */ 2463 atomic_thread_fence_acq_rel(); 2464 } 2465 2466 void 2467 vm_object_unbusy(vm_object_t obj) 2468 { 2469 2470 blockcount_release(&obj->busy, 1); 2471 } 2472 2473 void 2474 vm_object_busy_wait(vm_object_t obj, const char *wmesg) 2475 { 2476 2477 VM_OBJECT_ASSERT_UNLOCKED(obj); 2478 2479 (void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM); 2480 } 2481 2482 /* 2483 * Return the kvme type of the given object. 2484 * If vpp is not NULL, set it to the object's vm_object_vnode() or NULL. 2485 */ 2486 int 2487 vm_object_kvme_type(vm_object_t object, struct vnode **vpp) 2488 { 2489 2490 VM_OBJECT_ASSERT_LOCKED(object); 2491 if (vpp != NULL) 2492 *vpp = vm_object_vnode(object); 2493 switch (object->type) { 2494 case OBJT_DEFAULT: 2495 return (KVME_TYPE_DEFAULT); 2496 case OBJT_VNODE: 2497 return (KVME_TYPE_VNODE); 2498 case OBJT_SWAP: 2499 if ((object->flags & OBJ_TMPFS_NODE) != 0) 2500 return (KVME_TYPE_VNODE); 2501 return (KVME_TYPE_SWAP); 2502 case OBJT_DEVICE: 2503 return (KVME_TYPE_DEVICE); 2504 case OBJT_PHYS: 2505 return (KVME_TYPE_PHYS); 2506 case OBJT_DEAD: 2507 return (KVME_TYPE_DEAD); 2508 case OBJT_SG: 2509 return (KVME_TYPE_SG); 2510 case OBJT_MGTDEVICE: 2511 return (KVME_TYPE_MGTDEVICE); 2512 default: 2513 return (KVME_TYPE_UNKNOWN); 2514 } 2515 } 2516 2517 static int 2518 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS) 2519 { 2520 struct kinfo_vmobject *kvo; 2521 char *fullpath, *freepath; 2522 struct vnode *vp; 2523 struct vattr va; 2524 vm_object_t obj; 2525 vm_page_t m; 2526 int count, error; 2527 2528 if (req->oldptr == NULL) { 2529 /* 2530 * If an old buffer has not been provided, generate an 2531 * estimate of the space needed for a subsequent call. 2532 */ 2533 mtx_lock(&vm_object_list_mtx); 2534 count = 0; 2535 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2536 if (obj->type == OBJT_DEAD) 2537 continue; 2538 count++; 2539 } 2540 mtx_unlock(&vm_object_list_mtx); 2541 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) * 2542 count * 11 / 10)); 2543 } 2544 2545 kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK); 2546 error = 0; 2547 2548 /* 2549 * VM objects are type stable and are never removed from the 2550 * list once added. This allows us to safely read obj->object_list 2551 * after reacquiring the VM object lock. 2552 */ 2553 mtx_lock(&vm_object_list_mtx); 2554 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2555 if (obj->type == OBJT_DEAD) 2556 continue; 2557 VM_OBJECT_RLOCK(obj); 2558 if (obj->type == OBJT_DEAD) { 2559 VM_OBJECT_RUNLOCK(obj); 2560 continue; 2561 } 2562 mtx_unlock(&vm_object_list_mtx); 2563 kvo->kvo_size = ptoa(obj->size); 2564 kvo->kvo_resident = obj->resident_page_count; 2565 kvo->kvo_ref_count = obj->ref_count; 2566 kvo->kvo_shadow_count = obj->shadow_count; 2567 kvo->kvo_memattr = obj->memattr; 2568 kvo->kvo_active = 0; 2569 kvo->kvo_inactive = 0; 2570 TAILQ_FOREACH(m, &obj->memq, listq) { 2571 /* 2572 * A page may belong to the object but be 2573 * dequeued and set to PQ_NONE while the 2574 * object lock is not held. This makes the 2575 * reads of m->queue below racy, and we do not 2576 * count pages set to PQ_NONE. However, this 2577 * sysctl is only meant to give an 2578 * approximation of the system anyway. 2579 */ 2580 if (m->a.queue == PQ_ACTIVE) 2581 kvo->kvo_active++; 2582 else if (m->a.queue == PQ_INACTIVE) 2583 kvo->kvo_inactive++; 2584 } 2585 2586 kvo->kvo_vn_fileid = 0; 2587 kvo->kvo_vn_fsid = 0; 2588 kvo->kvo_vn_fsid_freebsd11 = 0; 2589 freepath = NULL; 2590 fullpath = ""; 2591 kvo->kvo_type = vm_object_kvme_type(obj, &vp); 2592 if (vp != NULL) 2593 vref(vp); 2594 VM_OBJECT_RUNLOCK(obj); 2595 if (vp != NULL) { 2596 vn_fullpath(vp, &fullpath, &freepath); 2597 vn_lock(vp, LK_SHARED | LK_RETRY); 2598 if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) { 2599 kvo->kvo_vn_fileid = va.va_fileid; 2600 kvo->kvo_vn_fsid = va.va_fsid; 2601 kvo->kvo_vn_fsid_freebsd11 = va.va_fsid; 2602 /* truncate */ 2603 } 2604 vput(vp); 2605 } 2606 2607 strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path)); 2608 if (freepath != NULL) 2609 free(freepath, M_TEMP); 2610 2611 /* Pack record size down */ 2612 kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path) 2613 + strlen(kvo->kvo_path) + 1; 2614 kvo->kvo_structsize = roundup(kvo->kvo_structsize, 2615 sizeof(uint64_t)); 2616 error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize); 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 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | 2626 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject", 2627 "List of VM objects"); 2628 2629 #include "opt_ddb.h" 2630 #ifdef DDB 2631 #include <sys/kernel.h> 2632 2633 #include <sys/cons.h> 2634 2635 #include <ddb/ddb.h> 2636 2637 static int 2638 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2639 { 2640 vm_map_t tmpm; 2641 vm_map_entry_t tmpe; 2642 vm_object_t obj; 2643 2644 if (map == 0) 2645 return 0; 2646 2647 if (entry == 0) { 2648 VM_MAP_ENTRY_FOREACH(tmpe, map) { 2649 if (_vm_object_in_map(map, object, tmpe)) { 2650 return 1; 2651 } 2652 } 2653 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2654 tmpm = entry->object.sub_map; 2655 VM_MAP_ENTRY_FOREACH(tmpe, tmpm) { 2656 if (_vm_object_in_map(tmpm, object, tmpe)) { 2657 return 1; 2658 } 2659 } 2660 } else if ((obj = entry->object.vm_object) != NULL) { 2661 for (; obj; obj = obj->backing_object) 2662 if (obj == object) { 2663 return 1; 2664 } 2665 } 2666 return 0; 2667 } 2668 2669 static int 2670 vm_object_in_map(vm_object_t object) 2671 { 2672 struct proc *p; 2673 2674 /* sx_slock(&allproc_lock); */ 2675 FOREACH_PROC_IN_SYSTEM(p) { 2676 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2677 continue; 2678 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2679 /* sx_sunlock(&allproc_lock); */ 2680 return 1; 2681 } 2682 } 2683 /* sx_sunlock(&allproc_lock); */ 2684 if (_vm_object_in_map(kernel_map, object, 0)) 2685 return 1; 2686 return 0; 2687 } 2688 2689 DB_SHOW_COMMAND(vmochk, vm_object_check) 2690 { 2691 vm_object_t object; 2692 2693 /* 2694 * make sure that internal objs are in a map somewhere 2695 * and none have zero ref counts. 2696 */ 2697 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2698 if ((object->flags & OBJ_ANON) != 0) { 2699 if (object->ref_count == 0) { 2700 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2701 (long)object->size); 2702 } 2703 if (!vm_object_in_map(object)) { 2704 db_printf( 2705 "vmochk: internal obj is not in a map: " 2706 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2707 object->ref_count, (u_long)object->size, 2708 (u_long)object->size, 2709 (void *)object->backing_object); 2710 } 2711 } 2712 if (db_pager_quit) 2713 return; 2714 } 2715 } 2716 2717 /* 2718 * vm_object_print: [ debug ] 2719 */ 2720 DB_SHOW_COMMAND(object, vm_object_print_static) 2721 { 2722 /* XXX convert args. */ 2723 vm_object_t object = (vm_object_t)addr; 2724 boolean_t full = have_addr; 2725 2726 vm_page_t p; 2727 2728 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2729 #define count was_count 2730 2731 int count; 2732 2733 if (object == NULL) 2734 return; 2735 2736 db_iprintf( 2737 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n", 2738 object, (int)object->type, (uintmax_t)object->size, 2739 object->resident_page_count, object->ref_count, object->flags, 2740 object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge); 2741 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2742 object->shadow_count, 2743 object->backing_object ? object->backing_object->ref_count : 0, 2744 object->backing_object, (uintmax_t)object->backing_object_offset); 2745 2746 if (!full) 2747 return; 2748 2749 db_indent += 2; 2750 count = 0; 2751 TAILQ_FOREACH(p, &object->memq, listq) { 2752 if (count == 0) 2753 db_iprintf("memory:="); 2754 else if (count == 6) { 2755 db_printf("\n"); 2756 db_iprintf(" ..."); 2757 count = 0; 2758 } else 2759 db_printf(","); 2760 count++; 2761 2762 db_printf("(off=0x%jx,page=0x%jx)", 2763 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2764 2765 if (db_pager_quit) 2766 break; 2767 } 2768 if (count != 0) 2769 db_printf("\n"); 2770 db_indent -= 2; 2771 } 2772 2773 /* XXX. */ 2774 #undef count 2775 2776 /* XXX need this non-static entry for calling from vm_map_print. */ 2777 void 2778 vm_object_print( 2779 /* db_expr_t */ long addr, 2780 boolean_t have_addr, 2781 /* db_expr_t */ long count, 2782 char *modif) 2783 { 2784 vm_object_print_static(addr, have_addr, count, modif); 2785 } 2786 2787 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2788 { 2789 vm_object_t object; 2790 vm_pindex_t fidx; 2791 vm_paddr_t pa; 2792 vm_page_t m, prev_m; 2793 int rcount, nl, c; 2794 2795 nl = 0; 2796 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2797 db_printf("new object: %p\n", (void *)object); 2798 if (nl > 18) { 2799 c = cngetc(); 2800 if (c != ' ') 2801 return; 2802 nl = 0; 2803 } 2804 nl++; 2805 rcount = 0; 2806 fidx = 0; 2807 pa = -1; 2808 TAILQ_FOREACH(m, &object->memq, listq) { 2809 if (m->pindex > 128) 2810 break; 2811 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2812 prev_m->pindex + 1 != m->pindex) { 2813 if (rcount) { 2814 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2815 (long)fidx, rcount, (long)pa); 2816 if (nl > 18) { 2817 c = cngetc(); 2818 if (c != ' ') 2819 return; 2820 nl = 0; 2821 } 2822 nl++; 2823 rcount = 0; 2824 } 2825 } 2826 if (rcount && 2827 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2828 ++rcount; 2829 continue; 2830 } 2831 if (rcount) { 2832 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2833 (long)fidx, rcount, (long)pa); 2834 if (nl > 18) { 2835 c = cngetc(); 2836 if (c != ' ') 2837 return; 2838 nl = 0; 2839 } 2840 nl++; 2841 } 2842 fidx = m->pindex; 2843 pa = VM_PAGE_TO_PHYS(m); 2844 rcount = 1; 2845 } 2846 if (rcount) { 2847 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2848 (long)fidx, rcount, (long)pa); 2849 if (nl > 18) { 2850 c = cngetc(); 2851 if (c != ' ') 2852 return; 2853 nl = 0; 2854 } 2855 nl++; 2856 } 2857 } 2858 } 2859 #endif /* DDB */ 2860