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/cpuset.h> 75 #include <sys/lock.h> 76 #include <sys/mman.h> 77 #include <sys/mount.h> 78 #include <sys/kernel.h> 79 #include <sys/pctrie.h> 80 #include <sys/sysctl.h> 81 #include <sys/mutex.h> 82 #include <sys/proc.h> /* for curproc, pageproc */ 83 #include <sys/refcount.h> 84 #include <sys/socket.h> 85 #include <sys/resourcevar.h> 86 #include <sys/refcount.h> 87 #include <sys/rwlock.h> 88 #include <sys/user.h> 89 #include <sys/vnode.h> 90 #include <sys/vmmeter.h> 91 #include <sys/sx.h> 92 93 #include <vm/vm.h> 94 #include <vm/vm_param.h> 95 #include <vm/pmap.h> 96 #include <vm/vm_map.h> 97 #include <vm/vm_object.h> 98 #include <vm/vm_page.h> 99 #include <vm/vm_pageout.h> 100 #include <vm/vm_pager.h> 101 #include <vm/vm_phys.h> 102 #include <vm/vm_pagequeue.h> 103 #include <vm/swap_pager.h> 104 #include <vm/vm_kern.h> 105 #include <vm/vm_extern.h> 106 #include <vm/vm_radix.h> 107 #include <vm/vm_reserv.h> 108 #include <vm/uma.h> 109 110 static int old_msync; 111 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 112 "Use old (insecure) msync behavior"); 113 114 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, 115 int pagerflags, int flags, boolean_t *allclean, 116 boolean_t *eio); 117 static boolean_t vm_object_page_remove_write(vm_page_t p, int flags, 118 boolean_t *allclean); 119 static void vm_object_qcollapse(vm_object_t object); 120 static void vm_object_vndeallocate(vm_object_t object); 121 static void vm_object_backing_remove(vm_object_t object); 122 123 /* 124 * Virtual memory objects maintain the actual data 125 * associated with allocated virtual memory. A given 126 * page of memory exists within exactly one object. 127 * 128 * An object is only deallocated when all "references" 129 * are given up. Only one "reference" to a given 130 * region of an object should be writeable. 131 * 132 * Associated with each object is a list of all resident 133 * memory pages belonging to that object; this list is 134 * maintained by the "vm_page" module, and locked by the object's 135 * lock. 136 * 137 * Each object also records a "pager" routine which is 138 * used to retrieve (and store) pages to the proper backing 139 * storage. In addition, objects may be backed by other 140 * objects from which they were virtual-copied. 141 * 142 * The only items within the object structure which are 143 * modified after time of creation are: 144 * reference count locked by object's lock 145 * pager routine locked by object's lock 146 * 147 */ 148 149 struct object_q vm_object_list; 150 struct mtx vm_object_list_mtx; /* lock for object list and count */ 151 152 struct vm_object kernel_object_store; 153 154 static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0, 155 "VM object stats"); 156 157 static counter_u64_t object_collapses = EARLY_COUNTER; 158 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, 159 &object_collapses, 160 "VM object collapses"); 161 162 static counter_u64_t object_bypasses = EARLY_COUNTER; 163 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, 164 &object_bypasses, 165 "VM object bypasses"); 166 167 static void 168 counter_startup(void) 169 { 170 171 object_collapses = counter_u64_alloc(M_WAITOK); 172 object_bypasses = counter_u64_alloc(M_WAITOK); 173 } 174 SYSINIT(object_counters, SI_SUB_CPU, SI_ORDER_ANY, counter_startup, NULL); 175 176 static uma_zone_t obj_zone; 177 178 static int vm_object_zinit(void *mem, int size, int flags); 179 180 #ifdef INVARIANTS 181 static void vm_object_zdtor(void *mem, int size, void *arg); 182 183 static void 184 vm_object_zdtor(void *mem, int size, void *arg) 185 { 186 vm_object_t object; 187 188 object = (vm_object_t)mem; 189 KASSERT(object->ref_count == 0, 190 ("object %p ref_count = %d", object, object->ref_count)); 191 KASSERT(TAILQ_EMPTY(&object->memq), 192 ("object %p has resident pages in its memq", object)); 193 KASSERT(vm_radix_is_empty(&object->rtree), 194 ("object %p has resident pages in its trie", object)); 195 #if VM_NRESERVLEVEL > 0 196 KASSERT(LIST_EMPTY(&object->rvq), 197 ("object %p has reservations", 198 object)); 199 #endif 200 KASSERT(REFCOUNT_COUNT(object->paging_in_progress) == 0, 201 ("object %p paging_in_progress = %d", 202 object, REFCOUNT_COUNT(object->paging_in_progress))); 203 KASSERT(object->busy == 0, 204 ("object %p busy = %d", 205 object, object->busy)); 206 KASSERT(object->resident_page_count == 0, 207 ("object %p resident_page_count = %d", 208 object, object->resident_page_count)); 209 KASSERT(object->shadow_count == 0, 210 ("object %p shadow_count = %d", 211 object, object->shadow_count)); 212 KASSERT(object->type == OBJT_DEAD, 213 ("object %p has non-dead type %d", 214 object, object->type)); 215 } 216 #endif 217 218 static int 219 vm_object_zinit(void *mem, int size, int flags) 220 { 221 vm_object_t object; 222 223 object = (vm_object_t)mem; 224 rw_init_flags(&object->lock, "vm object", RW_DUPOK | RW_NEW); 225 226 /* These are true for any object that has been freed */ 227 object->type = OBJT_DEAD; 228 vm_radix_init(&object->rtree); 229 refcount_init(&object->ref_count, 0); 230 refcount_init(&object->paging_in_progress, 0); 231 refcount_init(&object->busy, 0); 232 object->resident_page_count = 0; 233 object->shadow_count = 0; 234 object->flags = OBJ_DEAD; 235 236 mtx_lock(&vm_object_list_mtx); 237 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 238 mtx_unlock(&vm_object_list_mtx); 239 return (0); 240 } 241 242 static void 243 _vm_object_allocate(objtype_t type, vm_pindex_t size, u_short flags, 244 vm_object_t object, void *handle) 245 { 246 247 TAILQ_INIT(&object->memq); 248 LIST_INIT(&object->shadow_head); 249 250 object->type = type; 251 if (type == OBJT_SWAP) 252 pctrie_init(&object->un_pager.swp.swp_blks); 253 254 /* 255 * Ensure that swap_pager_swapoff() iteration over object_list 256 * sees up to date type and pctrie head if it observed 257 * non-dead object. 258 */ 259 atomic_thread_fence_rel(); 260 261 object->pg_color = 0; 262 object->flags = flags; 263 object->size = size; 264 object->domain.dr_policy = NULL; 265 object->generation = 1; 266 object->cleangeneration = 1; 267 refcount_init(&object->ref_count, 1); 268 object->memattr = VM_MEMATTR_DEFAULT; 269 object->cred = NULL; 270 object->charge = 0; 271 object->handle = handle; 272 object->backing_object = NULL; 273 object->backing_object_offset = (vm_ooffset_t) 0; 274 #if VM_NRESERVLEVEL > 0 275 LIST_INIT(&object->rvq); 276 #endif 277 umtx_shm_object_init(object); 278 } 279 280 /* 281 * vm_object_init: 282 * 283 * Initialize the VM objects module. 284 */ 285 void 286 vm_object_init(void) 287 { 288 TAILQ_INIT(&vm_object_list); 289 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 290 291 rw_init(&kernel_object->lock, "kernel vm object"); 292 _vm_object_allocate(OBJT_PHYS, atop(VM_MAX_KERNEL_ADDRESS - 293 VM_MIN_KERNEL_ADDRESS), OBJ_UNMANAGED, kernel_object, NULL); 294 #if VM_NRESERVLEVEL > 0 295 kernel_object->flags |= OBJ_COLORED; 296 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 297 #endif 298 299 /* 300 * The lock portion of struct vm_object must be type stable due 301 * to vm_pageout_fallback_object_lock locking a vm object 302 * without holding any references to it. 303 */ 304 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 305 #ifdef INVARIANTS 306 vm_object_zdtor, 307 #else 308 NULL, 309 #endif 310 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 311 312 vm_radix_zinit(); 313 } 314 315 void 316 vm_object_clear_flag(vm_object_t object, u_short bits) 317 { 318 319 VM_OBJECT_ASSERT_WLOCKED(object); 320 object->flags &= ~bits; 321 } 322 323 /* 324 * Sets the default memory attribute for the specified object. Pages 325 * that are allocated to this object are by default assigned this memory 326 * attribute. 327 * 328 * Presently, this function must be called before any pages are allocated 329 * to the object. In the future, this requirement may be relaxed for 330 * "default" and "swap" objects. 331 */ 332 int 333 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr) 334 { 335 336 VM_OBJECT_ASSERT_WLOCKED(object); 337 switch (object->type) { 338 case OBJT_DEFAULT: 339 case OBJT_DEVICE: 340 case OBJT_MGTDEVICE: 341 case OBJT_PHYS: 342 case OBJT_SG: 343 case OBJT_SWAP: 344 case OBJT_VNODE: 345 if (!TAILQ_EMPTY(&object->memq)) 346 return (KERN_FAILURE); 347 break; 348 case OBJT_DEAD: 349 return (KERN_INVALID_ARGUMENT); 350 default: 351 panic("vm_object_set_memattr: object %p is of undefined type", 352 object); 353 } 354 object->memattr = memattr; 355 return (KERN_SUCCESS); 356 } 357 358 void 359 vm_object_pip_add(vm_object_t object, short i) 360 { 361 362 refcount_acquiren(&object->paging_in_progress, i); 363 } 364 365 void 366 vm_object_pip_wakeup(vm_object_t object) 367 { 368 369 refcount_release(&object->paging_in_progress); 370 } 371 372 void 373 vm_object_pip_wakeupn(vm_object_t object, short i) 374 { 375 376 refcount_releasen(&object->paging_in_progress, i); 377 } 378 379 void 380 vm_object_pip_wait(vm_object_t object, char *waitid) 381 { 382 383 VM_OBJECT_ASSERT_WLOCKED(object); 384 385 while (REFCOUNT_COUNT(object->paging_in_progress) > 0) { 386 VM_OBJECT_WUNLOCK(object); 387 refcount_wait(&object->paging_in_progress, waitid, PVM); 388 VM_OBJECT_WLOCK(object); 389 } 390 } 391 392 void 393 vm_object_pip_wait_unlocked(vm_object_t object, char *waitid) 394 { 395 396 VM_OBJECT_ASSERT_UNLOCKED(object); 397 398 while (REFCOUNT_COUNT(object->paging_in_progress) > 0) 399 refcount_wait(&object->paging_in_progress, waitid, PVM); 400 } 401 402 /* 403 * vm_object_allocate: 404 * 405 * Returns a new object with the given size. 406 */ 407 vm_object_t 408 vm_object_allocate(objtype_t type, vm_pindex_t size) 409 { 410 vm_object_t object; 411 u_short flags; 412 413 switch (type) { 414 case OBJT_DEAD: 415 panic("vm_object_allocate: can't create OBJT_DEAD"); 416 case OBJT_DEFAULT: 417 case OBJT_SWAP: 418 flags = OBJ_COLORED; 419 break; 420 case OBJT_DEVICE: 421 case OBJT_SG: 422 flags = OBJ_FICTITIOUS | OBJ_UNMANAGED; 423 break; 424 case OBJT_MGTDEVICE: 425 flags = OBJ_FICTITIOUS; 426 break; 427 case OBJT_PHYS: 428 flags = OBJ_UNMANAGED; 429 break; 430 case OBJT_VNODE: 431 flags = 0; 432 break; 433 default: 434 panic("vm_object_allocate: type %d is undefined", type); 435 } 436 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 437 _vm_object_allocate(type, size, flags, object, NULL); 438 439 return (object); 440 } 441 442 /* 443 * vm_object_allocate_anon: 444 * 445 * Returns a new default object of the given size and marked as 446 * anonymous memory for special split/collapse handling. Color 447 * to be initialized by the caller. 448 */ 449 vm_object_t 450 vm_object_allocate_anon(vm_pindex_t size, vm_object_t backing_object, 451 struct ucred *cred, vm_size_t charge) 452 { 453 vm_object_t handle, object; 454 455 if (backing_object == NULL) 456 handle = NULL; 457 else if ((backing_object->flags & OBJ_ANON) != 0) 458 handle = backing_object->handle; 459 else 460 handle = backing_object; 461 object = uma_zalloc(obj_zone, M_WAITOK); 462 _vm_object_allocate(OBJT_DEFAULT, size, OBJ_ANON | OBJ_ONEMAPPING, 463 object, handle); 464 object->cred = cred; 465 object->charge = cred != NULL ? charge : 0; 466 return (object); 467 } 468 469 470 /* 471 * vm_object_reference: 472 * 473 * Gets another reference to the given object. Note: OBJ_DEAD 474 * objects can be referenced during final cleaning. 475 */ 476 void 477 vm_object_reference(vm_object_t object) 478 { 479 struct vnode *vp; 480 u_int old; 481 482 if (object == NULL) 483 return; 484 485 /* 486 * Many places assume exclusive access to objects with a single 487 * ref. vm_object_collapse() in particular will directly mainpulate 488 * references for objects in this state. vnode objects only need 489 * the lock for the first ref to reference the vnode. 490 */ 491 if (!refcount_acquire_if_gt(&object->ref_count, 492 object->type == OBJT_VNODE ? 0 : 1)) { 493 VM_OBJECT_RLOCK(object); 494 old = refcount_acquire(&object->ref_count); 495 if (object->type == OBJT_VNODE && old == 0) { 496 vp = object->handle; 497 vref(vp); 498 } 499 VM_OBJECT_RUNLOCK(object); 500 } 501 } 502 503 /* 504 * vm_object_reference_locked: 505 * 506 * Gets another reference to the given object. 507 * 508 * The object must be locked. 509 */ 510 void 511 vm_object_reference_locked(vm_object_t object) 512 { 513 struct vnode *vp; 514 u_int old; 515 516 VM_OBJECT_ASSERT_LOCKED(object); 517 old = refcount_acquire(&object->ref_count); 518 if (object->type == OBJT_VNODE && old == 0) { 519 vp = object->handle; 520 vref(vp); 521 } 522 } 523 524 /* 525 * Handle deallocating an object of type OBJT_VNODE. 526 */ 527 static void 528 vm_object_vndeallocate(vm_object_t object) 529 { 530 struct vnode *vp = (struct vnode *) object->handle; 531 bool last; 532 533 KASSERT(object->type == OBJT_VNODE, 534 ("vm_object_vndeallocate: not a vnode object")); 535 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 536 537 /* Object lock to protect handle lookup. */ 538 last = refcount_release(&object->ref_count); 539 VM_OBJECT_RUNLOCK(object); 540 541 if (!last) 542 return; 543 544 if (!umtx_shm_vnobj_persistent) 545 umtx_shm_object_terminated(object); 546 547 /* vrele may need the vnode lock. */ 548 vrele(vp); 549 } 550 551 /* 552 * vm_object_deallocate: 553 * 554 * Release a reference to the specified object, 555 * gained either through a vm_object_allocate 556 * or a vm_object_reference call. When all references 557 * are gone, storage associated with this object 558 * may be relinquished. 559 * 560 * No object may be locked. 561 */ 562 void 563 vm_object_deallocate(vm_object_t object) 564 { 565 vm_object_t robject, temp; 566 bool released; 567 568 while (object != NULL) { 569 /* 570 * If the reference count goes to 0 we start calling 571 * vm_object_terminate() on the object chain. A ref count 572 * of 1 may be a special case depending on the shadow count 573 * being 0 or 1. These cases require a write lock on the 574 * object. 575 */ 576 if ((object->flags & OBJ_ANON) == 0) 577 released = refcount_release_if_gt(&object->ref_count, 1); 578 else 579 released = refcount_release_if_gt(&object->ref_count, 2); 580 if (released) 581 return; 582 583 if (object->type == OBJT_VNODE) { 584 VM_OBJECT_RLOCK(object); 585 if (object->type == OBJT_VNODE) { 586 vm_object_vndeallocate(object); 587 return; 588 } 589 VM_OBJECT_RUNLOCK(object); 590 } 591 592 VM_OBJECT_WLOCK(object); 593 KASSERT(object->ref_count > 0, 594 ("vm_object_deallocate: object deallocated too many times: %d", 595 object->type)); 596 597 if (refcount_release(&object->ref_count)) 598 goto doterm; 599 if (object->ref_count > 1) { 600 VM_OBJECT_WUNLOCK(object); 601 return; 602 } else if (object->ref_count == 1) { 603 if (object->shadow_count == 0 && 604 (object->flags & OBJ_ANON) != 0) { 605 vm_object_set_flag(object, OBJ_ONEMAPPING); 606 } else if (object->shadow_count == 1) { 607 KASSERT((object->flags & OBJ_ANON) != 0, 608 ("obj %p with shadow_count > 0 is not anon", 609 object)); 610 robject = LIST_FIRST(&object->shadow_head); 611 KASSERT(robject != NULL, 612 ("vm_object_deallocate: ref_count: %d, " 613 "shadow_count: %d", object->ref_count, 614 object->shadow_count)); 615 KASSERT((robject->flags & OBJ_TMPFS_NODE) == 0, 616 ("shadowed tmpfs v_object %p", object)); 617 if (!VM_OBJECT_TRYWLOCK(robject)) { 618 /* 619 * Avoid a potential deadlock. 620 */ 621 refcount_acquire(&object->ref_count); 622 VM_OBJECT_WUNLOCK(object); 623 /* 624 * More likely than not the thread 625 * holding robject's lock has lower 626 * priority than the current thread. 627 * Let the lower priority thread run. 628 */ 629 pause("vmo_de", 1); 630 continue; 631 } 632 /* 633 * Collapse object into its shadow unless its 634 * shadow is dead. In that case, object will 635 * be deallocated by the thread that is 636 * deallocating its shadow. 637 */ 638 if ((robject->flags & 639 (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON) { 640 641 refcount_acquire(&robject->ref_count); 642 retry: 643 if (REFCOUNT_COUNT(robject->paging_in_progress) > 0) { 644 VM_OBJECT_WUNLOCK(object); 645 vm_object_pip_wait(robject, 646 "objde1"); 647 temp = robject->backing_object; 648 if (object == temp) { 649 VM_OBJECT_WLOCK(object); 650 goto retry; 651 } 652 } else if (REFCOUNT_COUNT(object->paging_in_progress) > 0) { 653 VM_OBJECT_WUNLOCK(robject); 654 VM_OBJECT_WUNLOCK(object); 655 refcount_wait( 656 &object->paging_in_progress, 657 "objde2", PVM); 658 VM_OBJECT_WLOCK(robject); 659 temp = robject->backing_object; 660 if (object == temp) { 661 VM_OBJECT_WLOCK(object); 662 goto retry; 663 } 664 } else 665 VM_OBJECT_WUNLOCK(object); 666 667 if (robject->ref_count == 1) { 668 refcount_release(&robject->ref_count); 669 object = robject; 670 goto doterm; 671 } 672 object = robject; 673 vm_object_collapse(object); 674 VM_OBJECT_WUNLOCK(object); 675 continue; 676 } 677 VM_OBJECT_WUNLOCK(robject); 678 } 679 VM_OBJECT_WUNLOCK(object); 680 return; 681 } 682 doterm: 683 umtx_shm_object_terminated(object); 684 temp = object->backing_object; 685 if (temp != NULL) { 686 KASSERT((object->flags & OBJ_TMPFS_NODE) == 0, 687 ("shadowed tmpfs v_object 2 %p", object)); 688 vm_object_backing_remove(object); 689 } 690 /* 691 * Don't double-terminate, we could be in a termination 692 * recursion due to the terminate having to sync data 693 * to disk. 694 */ 695 if ((object->flags & OBJ_DEAD) == 0) { 696 vm_object_set_flag(object, OBJ_DEAD); 697 vm_object_terminate(object); 698 } else 699 VM_OBJECT_WUNLOCK(object); 700 object = temp; 701 } 702 } 703 704 /* 705 * vm_object_destroy removes the object from the global object list 706 * and frees the space for the object. 707 */ 708 void 709 vm_object_destroy(vm_object_t object) 710 { 711 712 /* 713 * Release the allocation charge. 714 */ 715 if (object->cred != NULL) { 716 swap_release_by_cred(object->charge, object->cred); 717 object->charge = 0; 718 crfree(object->cred); 719 object->cred = NULL; 720 } 721 722 /* 723 * Free the space for the object. 724 */ 725 uma_zfree(obj_zone, object); 726 } 727 728 static void 729 vm_object_backing_remove_locked(vm_object_t object) 730 { 731 vm_object_t backing_object; 732 733 backing_object = object->backing_object; 734 VM_OBJECT_ASSERT_WLOCKED(object); 735 VM_OBJECT_ASSERT_WLOCKED(backing_object); 736 737 if ((object->flags & OBJ_SHADOWLIST) != 0) { 738 LIST_REMOVE(object, shadow_list); 739 backing_object->shadow_count--; 740 object->flags &= ~OBJ_SHADOWLIST; 741 } 742 object->backing_object = NULL; 743 } 744 745 static void 746 vm_object_backing_remove(vm_object_t object) 747 { 748 vm_object_t backing_object; 749 750 VM_OBJECT_ASSERT_WLOCKED(object); 751 752 if ((object->flags & OBJ_SHADOWLIST) != 0) { 753 backing_object = object->backing_object; 754 VM_OBJECT_WLOCK(backing_object); 755 vm_object_backing_remove_locked(object); 756 VM_OBJECT_WUNLOCK(backing_object); 757 } else 758 object->backing_object = NULL; 759 } 760 761 static void 762 vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object) 763 { 764 765 VM_OBJECT_ASSERT_WLOCKED(object); 766 767 if ((backing_object->flags & OBJ_ANON) != 0) { 768 VM_OBJECT_ASSERT_WLOCKED(backing_object); 769 LIST_INSERT_HEAD(&backing_object->shadow_head, object, 770 shadow_list); 771 backing_object->shadow_count++; 772 object->flags |= OBJ_SHADOWLIST; 773 } 774 object->backing_object = backing_object; 775 } 776 777 static void 778 vm_object_backing_insert(vm_object_t object, vm_object_t backing_object) 779 { 780 781 VM_OBJECT_ASSERT_WLOCKED(object); 782 783 if ((backing_object->flags & OBJ_ANON) != 0) { 784 VM_OBJECT_WLOCK(backing_object); 785 vm_object_backing_insert_locked(object, backing_object); 786 VM_OBJECT_WUNLOCK(backing_object); 787 } else 788 object->backing_object = backing_object; 789 } 790 791 792 /* 793 * vm_object_terminate_pages removes any remaining pageable pages 794 * from the object and resets the object to an empty state. 795 */ 796 static void 797 vm_object_terminate_pages(vm_object_t object) 798 { 799 vm_page_t p, p_next; 800 801 VM_OBJECT_ASSERT_WLOCKED(object); 802 803 /* 804 * Free any remaining pageable pages. This also removes them from the 805 * paging queues. However, don't free wired pages, just remove them 806 * from the object. Rather than incrementally removing each page from 807 * the object, the page and object are reset to any empty state. 808 */ 809 TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) { 810 vm_page_assert_unbusied(p); 811 KASSERT(p->object == object && 812 (p->ref_count & VPRC_OBJREF) != 0, 813 ("vm_object_terminate_pages: page %p is inconsistent", p)); 814 815 p->object = NULL; 816 if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) { 817 VM_CNT_INC(v_pfree); 818 vm_page_free(p); 819 } 820 } 821 822 /* 823 * If the object contained any pages, then reset it to an empty state. 824 * None of the object's fields, including "resident_page_count", were 825 * modified by the preceding loop. 826 */ 827 if (object->resident_page_count != 0) { 828 vm_radix_reclaim_allnodes(&object->rtree); 829 TAILQ_INIT(&object->memq); 830 object->resident_page_count = 0; 831 if (object->type == OBJT_VNODE) 832 vdrop(object->handle); 833 } 834 } 835 836 /* 837 * vm_object_terminate actually destroys the specified object, freeing 838 * up all previously used resources. 839 * 840 * The object must be locked. 841 * This routine may block. 842 */ 843 void 844 vm_object_terminate(vm_object_t object) 845 { 846 VM_OBJECT_ASSERT_WLOCKED(object); 847 KASSERT((object->flags & OBJ_DEAD) != 0, 848 ("terminating non-dead obj %p", object)); 849 850 /* 851 * wait for the pageout daemon to be done with the object 852 */ 853 vm_object_pip_wait(object, "objtrm"); 854 855 KASSERT(!REFCOUNT_COUNT(object->paging_in_progress), 856 ("vm_object_terminate: pageout in progress")); 857 858 KASSERT(object->ref_count == 0, 859 ("vm_object_terminate: object with references, ref_count=%d", 860 object->ref_count)); 861 862 if ((object->flags & OBJ_PG_DTOR) == 0) 863 vm_object_terminate_pages(object); 864 865 #if VM_NRESERVLEVEL > 0 866 if (__predict_false(!LIST_EMPTY(&object->rvq))) 867 vm_reserv_break_all(object); 868 #endif 869 870 KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT || 871 object->type == OBJT_SWAP, 872 ("%s: non-swap obj %p has cred", __func__, object)); 873 874 /* 875 * Let the pager know object is dead. 876 */ 877 vm_pager_deallocate(object); 878 VM_OBJECT_WUNLOCK(object); 879 880 vm_object_destroy(object); 881 } 882 883 /* 884 * Make the page read-only so that we can clear the object flags. However, if 885 * this is a nosync mmap then the object is likely to stay dirty so do not 886 * mess with the page and do not clear the object flags. Returns TRUE if the 887 * page should be flushed, and FALSE otherwise. 888 */ 889 static boolean_t 890 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean) 891 { 892 893 vm_page_assert_busied(p); 894 895 /* 896 * If we have been asked to skip nosync pages and this is a 897 * nosync page, skip it. Note that the object flags were not 898 * cleared in this case so we do not have to set them. 899 */ 900 if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) { 901 *allclean = FALSE; 902 return (FALSE); 903 } else { 904 pmap_remove_write(p); 905 return (p->dirty != 0); 906 } 907 } 908 909 /* 910 * vm_object_page_clean 911 * 912 * Clean all dirty pages in the specified range of object. Leaves page 913 * on whatever queue it is currently on. If NOSYNC is set then do not 914 * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC), 915 * leaving the object dirty. 916 * 917 * When stuffing pages asynchronously, allow clustering. XXX we need a 918 * synchronous clustering mode implementation. 919 * 920 * Odd semantics: if start == end, we clean everything. 921 * 922 * The object must be locked. 923 * 924 * Returns FALSE if some page from the range was not written, as 925 * reported by the pager, and TRUE otherwise. 926 */ 927 boolean_t 928 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end, 929 int flags) 930 { 931 vm_page_t np, p; 932 vm_pindex_t pi, tend, tstart; 933 int curgeneration, n, pagerflags; 934 boolean_t eio, res, allclean; 935 936 VM_OBJECT_ASSERT_WLOCKED(object); 937 938 if (object->type != OBJT_VNODE || !vm_object_mightbedirty(object) || 939 object->resident_page_count == 0) 940 return (TRUE); 941 942 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ? 943 VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 944 pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0; 945 946 tstart = OFF_TO_IDX(start); 947 tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK); 948 allclean = tstart == 0 && tend >= object->size; 949 res = TRUE; 950 951 rescan: 952 curgeneration = object->generation; 953 954 for (p = vm_page_find_least(object, tstart); p != NULL; p = np) { 955 pi = p->pindex; 956 if (pi >= tend) 957 break; 958 np = TAILQ_NEXT(p, listq); 959 if (vm_page_none_valid(p)) 960 continue; 961 if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) { 962 if (object->generation != curgeneration && 963 (flags & OBJPC_SYNC) != 0) 964 goto rescan; 965 np = vm_page_find_least(object, pi); 966 continue; 967 } 968 if (!vm_object_page_remove_write(p, flags, &allclean)) { 969 vm_page_xunbusy(p); 970 continue; 971 } 972 973 n = vm_object_page_collect_flush(object, p, pagerflags, 974 flags, &allclean, &eio); 975 if (eio) { 976 res = FALSE; 977 allclean = FALSE; 978 } 979 if (object->generation != curgeneration && 980 (flags & OBJPC_SYNC) != 0) 981 goto rescan; 982 983 /* 984 * If the VOP_PUTPAGES() did a truncated write, so 985 * that even the first page of the run is not fully 986 * written, vm_pageout_flush() returns 0 as the run 987 * length. Since the condition that caused truncated 988 * write may be permanent, e.g. exhausted free space, 989 * accepting n == 0 would cause an infinite loop. 990 * 991 * Forwarding the iterator leaves the unwritten page 992 * behind, but there is not much we can do there if 993 * filesystem refuses to write it. 994 */ 995 if (n == 0) { 996 n = 1; 997 allclean = FALSE; 998 } 999 np = vm_page_find_least(object, pi + n); 1000 } 1001 #if 0 1002 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0); 1003 #endif 1004 1005 if (allclean) 1006 object->cleangeneration = curgeneration; 1007 return (res); 1008 } 1009 1010 static int 1011 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags, 1012 int flags, boolean_t *allclean, boolean_t *eio) 1013 { 1014 vm_page_t ma[vm_pageout_page_count], p_first, tp; 1015 int count, i, mreq, runlen; 1016 1017 vm_page_lock_assert(p, MA_NOTOWNED); 1018 vm_page_assert_xbusied(p); 1019 VM_OBJECT_ASSERT_WLOCKED(object); 1020 1021 count = 1; 1022 mreq = 0; 1023 1024 for (tp = p; count < vm_pageout_page_count; count++) { 1025 tp = vm_page_next(tp); 1026 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1027 break; 1028 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1029 vm_page_xunbusy(tp); 1030 break; 1031 } 1032 } 1033 1034 for (p_first = p; count < vm_pageout_page_count; count++) { 1035 tp = vm_page_prev(p_first); 1036 if (tp == NULL || vm_page_tryxbusy(tp) == 0) 1037 break; 1038 if (!vm_object_page_remove_write(tp, flags, allclean)) { 1039 vm_page_xunbusy(tp); 1040 break; 1041 } 1042 p_first = tp; 1043 mreq++; 1044 } 1045 1046 for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++) 1047 ma[i] = tp; 1048 1049 vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio); 1050 return (runlen); 1051 } 1052 1053 /* 1054 * Note that there is absolutely no sense in writing out 1055 * anonymous objects, so we track down the vnode object 1056 * to write out. 1057 * We invalidate (remove) all pages from the address space 1058 * for semantic correctness. 1059 * 1060 * If the backing object is a device object with unmanaged pages, then any 1061 * mappings to the specified range of pages must be removed before this 1062 * function is called. 1063 * 1064 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1065 * may start out with a NULL object. 1066 */ 1067 boolean_t 1068 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1069 boolean_t syncio, boolean_t invalidate) 1070 { 1071 vm_object_t backing_object; 1072 struct vnode *vp; 1073 struct mount *mp; 1074 int error, flags, fsync_after; 1075 boolean_t res; 1076 1077 if (object == NULL) 1078 return (TRUE); 1079 res = TRUE; 1080 error = 0; 1081 VM_OBJECT_WLOCK(object); 1082 while ((backing_object = object->backing_object) != NULL) { 1083 VM_OBJECT_WLOCK(backing_object); 1084 offset += object->backing_object_offset; 1085 VM_OBJECT_WUNLOCK(object); 1086 object = backing_object; 1087 if (object->size < OFF_TO_IDX(offset + size)) 1088 size = IDX_TO_OFF(object->size) - offset; 1089 } 1090 /* 1091 * Flush pages if writing is allowed, invalidate them 1092 * if invalidation requested. Pages undergoing I/O 1093 * will be ignored by vm_object_page_remove(). 1094 * 1095 * We cannot lock the vnode and then wait for paging 1096 * to complete without deadlocking against vm_fault. 1097 * Instead we simply call vm_object_page_remove() and 1098 * allow it to block internally on a page-by-page 1099 * basis when it encounters pages undergoing async 1100 * I/O. 1101 */ 1102 if (object->type == OBJT_VNODE && 1103 vm_object_mightbedirty(object) != 0 && 1104 ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) { 1105 VM_OBJECT_WUNLOCK(object); 1106 (void) vn_start_write(vp, &mp, V_WAIT); 1107 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1108 if (syncio && !invalidate && offset == 0 && 1109 atop(size) == object->size) { 1110 /* 1111 * If syncing the whole mapping of the file, 1112 * it is faster to schedule all the writes in 1113 * async mode, also allowing the clustering, 1114 * and then wait for i/o to complete. 1115 */ 1116 flags = 0; 1117 fsync_after = TRUE; 1118 } else { 1119 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1120 flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0; 1121 fsync_after = FALSE; 1122 } 1123 VM_OBJECT_WLOCK(object); 1124 res = vm_object_page_clean(object, offset, offset + size, 1125 flags); 1126 VM_OBJECT_WUNLOCK(object); 1127 if (fsync_after) 1128 error = VOP_FSYNC(vp, MNT_WAIT, curthread); 1129 VOP_UNLOCK(vp); 1130 vn_finished_write(mp); 1131 if (error != 0) 1132 res = FALSE; 1133 VM_OBJECT_WLOCK(object); 1134 } 1135 if ((object->type == OBJT_VNODE || 1136 object->type == OBJT_DEVICE) && invalidate) { 1137 if (object->type == OBJT_DEVICE) 1138 /* 1139 * The option OBJPR_NOTMAPPED must be passed here 1140 * because vm_object_page_remove() cannot remove 1141 * unmanaged mappings. 1142 */ 1143 flags = OBJPR_NOTMAPPED; 1144 else if (old_msync) 1145 flags = 0; 1146 else 1147 flags = OBJPR_CLEANONLY; 1148 vm_object_page_remove(object, OFF_TO_IDX(offset), 1149 OFF_TO_IDX(offset + size + PAGE_MASK), flags); 1150 } 1151 VM_OBJECT_WUNLOCK(object); 1152 return (res); 1153 } 1154 1155 /* 1156 * Determine whether the given advice can be applied to the object. Advice is 1157 * not applied to unmanaged pages since they never belong to page queues, and 1158 * since MADV_FREE is destructive, it can apply only to anonymous pages that 1159 * have been mapped at most once. 1160 */ 1161 static bool 1162 vm_object_advice_applies(vm_object_t object, int advice) 1163 { 1164 1165 if ((object->flags & OBJ_UNMANAGED) != 0) 1166 return (false); 1167 if (advice != MADV_FREE) 1168 return (true); 1169 return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) == 1170 (OBJ_ONEMAPPING | OBJ_ANON)); 1171 } 1172 1173 static void 1174 vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex, 1175 vm_size_t size) 1176 { 1177 1178 if (advice == MADV_FREE && object->type == OBJT_SWAP) 1179 swap_pager_freespace(object, pindex, size); 1180 } 1181 1182 /* 1183 * vm_object_madvise: 1184 * 1185 * Implements the madvise function at the object/page level. 1186 * 1187 * MADV_WILLNEED (any object) 1188 * 1189 * Activate the specified pages if they are resident. 1190 * 1191 * MADV_DONTNEED (any object) 1192 * 1193 * Deactivate the specified pages if they are resident. 1194 * 1195 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1196 * OBJ_ONEMAPPING only) 1197 * 1198 * Deactivate and clean the specified pages if they are 1199 * resident. This permits the process to reuse the pages 1200 * without faulting or the kernel to reclaim the pages 1201 * without I/O. 1202 */ 1203 void 1204 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end, 1205 int advice) 1206 { 1207 vm_pindex_t tpindex; 1208 vm_object_t backing_object, tobject; 1209 vm_page_t m, tm; 1210 1211 if (object == NULL) 1212 return; 1213 1214 relookup: 1215 VM_OBJECT_WLOCK(object); 1216 if (!vm_object_advice_applies(object, advice)) { 1217 VM_OBJECT_WUNLOCK(object); 1218 return; 1219 } 1220 for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) { 1221 tobject = object; 1222 1223 /* 1224 * If the next page isn't resident in the top-level object, we 1225 * need to search the shadow chain. When applying MADV_FREE, we 1226 * take care to release any swap space used to store 1227 * non-resident pages. 1228 */ 1229 if (m == NULL || pindex < m->pindex) { 1230 /* 1231 * Optimize a common case: if the top-level object has 1232 * no backing object, we can skip over the non-resident 1233 * range in constant time. 1234 */ 1235 if (object->backing_object == NULL) { 1236 tpindex = (m != NULL && m->pindex < end) ? 1237 m->pindex : end; 1238 vm_object_madvise_freespace(object, advice, 1239 pindex, tpindex - pindex); 1240 if ((pindex = tpindex) == end) 1241 break; 1242 goto next_page; 1243 } 1244 1245 tpindex = pindex; 1246 do { 1247 vm_object_madvise_freespace(tobject, advice, 1248 tpindex, 1); 1249 /* 1250 * Prepare to search the next object in the 1251 * chain. 1252 */ 1253 backing_object = tobject->backing_object; 1254 if (backing_object == NULL) 1255 goto next_pindex; 1256 VM_OBJECT_WLOCK(backing_object); 1257 tpindex += 1258 OFF_TO_IDX(tobject->backing_object_offset); 1259 if (tobject != object) 1260 VM_OBJECT_WUNLOCK(tobject); 1261 tobject = backing_object; 1262 if (!vm_object_advice_applies(tobject, advice)) 1263 goto next_pindex; 1264 } while ((tm = vm_page_lookup(tobject, tpindex)) == 1265 NULL); 1266 } else { 1267 next_page: 1268 tm = m; 1269 m = TAILQ_NEXT(m, listq); 1270 } 1271 1272 /* 1273 * If the page is not in a normal state, skip it. The page 1274 * can not be invalidated while the object lock is held. 1275 */ 1276 if (!vm_page_all_valid(tm) || vm_page_wired(tm)) 1277 goto next_pindex; 1278 KASSERT((tm->flags & PG_FICTITIOUS) == 0, 1279 ("vm_object_madvise: page %p is fictitious", tm)); 1280 KASSERT((tm->oflags & VPO_UNMANAGED) == 0, 1281 ("vm_object_madvise: page %p is not managed", tm)); 1282 if (vm_page_tryxbusy(tm) == 0) { 1283 if (object != tobject) 1284 VM_OBJECT_WUNLOCK(object); 1285 if (advice == MADV_WILLNEED) { 1286 /* 1287 * Reference the page before unlocking and 1288 * sleeping so that the page daemon is less 1289 * likely to reclaim it. 1290 */ 1291 vm_page_aflag_set(tm, PGA_REFERENCED); 1292 } 1293 vm_page_busy_sleep(tm, "madvpo", false); 1294 goto relookup; 1295 } 1296 vm_page_advise(tm, advice); 1297 vm_page_xunbusy(tm); 1298 vm_object_madvise_freespace(tobject, advice, tm->pindex, 1); 1299 next_pindex: 1300 if (tobject != object) 1301 VM_OBJECT_WUNLOCK(tobject); 1302 } 1303 VM_OBJECT_WUNLOCK(object); 1304 } 1305 1306 /* 1307 * vm_object_shadow: 1308 * 1309 * Create a new object which is backed by the 1310 * specified existing object range. The source 1311 * object reference is deallocated. 1312 * 1313 * The new object and offset into that object 1314 * are returned in the source parameters. 1315 */ 1316 void 1317 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length, 1318 struct ucred *cred, bool shared) 1319 { 1320 vm_object_t source; 1321 vm_object_t result; 1322 1323 source = *object; 1324 1325 /* 1326 * Don't create the new object if the old object isn't shared. 1327 * 1328 * If we hold the only reference we can guarantee that it won't 1329 * increase while we have the map locked. Otherwise the race is 1330 * harmless and we will end up with an extra shadow object that 1331 * will be collapsed later. 1332 */ 1333 if (source != NULL && source->ref_count == 1 && 1334 (source->flags & OBJ_ANON) != 0) 1335 return; 1336 1337 /* 1338 * Allocate a new object with the given length. 1339 */ 1340 result = vm_object_allocate_anon(atop(length), source, cred, length); 1341 1342 /* 1343 * Store the offset into the source object, and fix up the offset into 1344 * the new object. 1345 */ 1346 result->backing_object_offset = *offset; 1347 1348 if (shared || source != NULL) { 1349 VM_OBJECT_WLOCK(result); 1350 1351 /* 1352 * The new object shadows the source object, adding a 1353 * reference to it. Our caller changes his reference 1354 * to point to the new object, removing a reference to 1355 * the source object. Net result: no change of 1356 * reference count, unless the caller needs to add one 1357 * more reference due to forking a shared map entry. 1358 */ 1359 if (shared) { 1360 vm_object_reference_locked(result); 1361 vm_object_clear_flag(result, OBJ_ONEMAPPING); 1362 } 1363 1364 /* 1365 * Try to optimize the result object's page color when 1366 * shadowing in order to maintain page coloring 1367 * consistency in the combined shadowed object. 1368 */ 1369 if (source != NULL) { 1370 vm_object_backing_insert(result, source); 1371 result->domain = source->domain; 1372 #if VM_NRESERVLEVEL > 0 1373 result->flags |= source->flags & OBJ_COLORED; 1374 result->pg_color = (source->pg_color + 1375 OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER - 1376 1)) - 1); 1377 #endif 1378 } 1379 VM_OBJECT_WUNLOCK(result); 1380 } 1381 1382 /* 1383 * Return the new things 1384 */ 1385 *offset = 0; 1386 *object = result; 1387 } 1388 1389 /* 1390 * vm_object_split: 1391 * 1392 * Split the pages in a map entry into a new object. This affords 1393 * easier removal of unused pages, and keeps object inheritance from 1394 * being a negative impact on memory usage. 1395 */ 1396 void 1397 vm_object_split(vm_map_entry_t entry) 1398 { 1399 vm_page_t m, m_next; 1400 vm_object_t orig_object, new_object, source; 1401 vm_pindex_t idx, offidxstart; 1402 vm_size_t size; 1403 1404 orig_object = entry->object.vm_object; 1405 if ((orig_object->flags & OBJ_ANON) == 0) 1406 return; 1407 if (orig_object->ref_count <= 1) 1408 return; 1409 VM_OBJECT_WUNLOCK(orig_object); 1410 1411 offidxstart = OFF_TO_IDX(entry->offset); 1412 size = atop(entry->end - entry->start); 1413 1414 /* 1415 * If swap_pager_copy() is later called, it will convert new_object 1416 * into a swap object. 1417 */ 1418 new_object = vm_object_allocate_anon(size, orig_object, 1419 orig_object->cred, ptoa(size)); 1420 1421 /* 1422 * At this point, the new object is still private, so the order in 1423 * which the original and new objects are locked does not matter. 1424 */ 1425 VM_OBJECT_WLOCK(new_object); 1426 VM_OBJECT_WLOCK(orig_object); 1427 new_object->domain = orig_object->domain; 1428 source = orig_object->backing_object; 1429 if (source != NULL) { 1430 if ((source->flags & (OBJ_ANON | OBJ_DEAD)) != 0) { 1431 VM_OBJECT_WLOCK(source); 1432 if ((source->flags & OBJ_DEAD) != 0) { 1433 VM_OBJECT_WUNLOCK(source); 1434 VM_OBJECT_WUNLOCK(orig_object); 1435 VM_OBJECT_WUNLOCK(new_object); 1436 new_object->cred = NULL; 1437 vm_object_deallocate(new_object); 1438 VM_OBJECT_WLOCK(orig_object); 1439 return; 1440 } 1441 vm_object_backing_insert_locked(new_object, source); 1442 vm_object_reference_locked(source); /* for new_object */ 1443 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1444 VM_OBJECT_WUNLOCK(source); 1445 } else { 1446 vm_object_backing_insert(new_object, source); 1447 vm_object_reference(source); 1448 } 1449 new_object->backing_object_offset = 1450 orig_object->backing_object_offset + entry->offset; 1451 } 1452 if (orig_object->cred != NULL) { 1453 crhold(orig_object->cred); 1454 KASSERT(orig_object->charge >= ptoa(size), 1455 ("orig_object->charge < 0")); 1456 orig_object->charge -= ptoa(size); 1457 } 1458 retry: 1459 m = vm_page_find_least(orig_object, offidxstart); 1460 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1461 m = m_next) { 1462 m_next = TAILQ_NEXT(m, listq); 1463 1464 /* 1465 * We must wait for pending I/O to complete before we can 1466 * rename the page. 1467 * 1468 * We do not have to VM_PROT_NONE the page as mappings should 1469 * not be changed by this operation. 1470 */ 1471 if (vm_page_tryxbusy(m) == 0) { 1472 VM_OBJECT_WUNLOCK(new_object); 1473 vm_page_sleep_if_busy(m, "spltwt"); 1474 VM_OBJECT_WLOCK(new_object); 1475 goto retry; 1476 } 1477 1478 /* 1479 * The page was left invalid. Likely placed there by 1480 * an incomplete fault. Just remove and ignore. 1481 */ 1482 if (vm_page_none_valid(m)) { 1483 if (vm_page_remove(m)) 1484 vm_page_free(m); 1485 continue; 1486 } 1487 1488 /* vm_page_rename() will dirty the page. */ 1489 if (vm_page_rename(m, new_object, idx)) { 1490 vm_page_xunbusy(m); 1491 VM_OBJECT_WUNLOCK(new_object); 1492 VM_OBJECT_WUNLOCK(orig_object); 1493 vm_radix_wait(); 1494 VM_OBJECT_WLOCK(orig_object); 1495 VM_OBJECT_WLOCK(new_object); 1496 goto retry; 1497 } 1498 1499 #if VM_NRESERVLEVEL > 0 1500 /* 1501 * If some of the reservation's allocated pages remain with 1502 * the original object, then transferring the reservation to 1503 * the new object is neither particularly beneficial nor 1504 * particularly harmful as compared to leaving the reservation 1505 * with the original object. If, however, all of the 1506 * reservation's allocated pages are transferred to the new 1507 * object, then transferring the reservation is typically 1508 * beneficial. Determining which of these two cases applies 1509 * would be more costly than unconditionally renaming the 1510 * reservation. 1511 */ 1512 vm_reserv_rename(m, new_object, orig_object, offidxstart); 1513 #endif 1514 if (orig_object->type != OBJT_SWAP) 1515 vm_page_xunbusy(m); 1516 } 1517 if (orig_object->type == OBJT_SWAP) { 1518 /* 1519 * swap_pager_copy() can sleep, in which case the orig_object's 1520 * and new_object's locks are released and reacquired. 1521 */ 1522 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1523 TAILQ_FOREACH(m, &new_object->memq, listq) 1524 vm_page_xunbusy(m); 1525 } 1526 VM_OBJECT_WUNLOCK(orig_object); 1527 VM_OBJECT_WUNLOCK(new_object); 1528 entry->object.vm_object = new_object; 1529 entry->offset = 0LL; 1530 vm_object_deallocate(orig_object); 1531 VM_OBJECT_WLOCK(new_object); 1532 } 1533 1534 #define OBSC_COLLAPSE_NOWAIT 0x0002 1535 #define OBSC_COLLAPSE_WAIT 0x0004 1536 1537 static vm_page_t 1538 vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p, vm_page_t next, 1539 int op) 1540 { 1541 vm_object_t backing_object; 1542 1543 VM_OBJECT_ASSERT_WLOCKED(object); 1544 backing_object = object->backing_object; 1545 VM_OBJECT_ASSERT_WLOCKED(backing_object); 1546 1547 KASSERT(p == NULL || p->object == object || p->object == backing_object, 1548 ("invalid ownership %p %p %p", p, object, backing_object)); 1549 if ((op & OBSC_COLLAPSE_NOWAIT) != 0) 1550 return (next); 1551 /* The page is only NULL when rename fails. */ 1552 if (p == NULL) { 1553 VM_OBJECT_WUNLOCK(object); 1554 VM_OBJECT_WUNLOCK(backing_object); 1555 vm_radix_wait(); 1556 } else { 1557 if (p->object == object) 1558 VM_OBJECT_WUNLOCK(backing_object); 1559 else 1560 VM_OBJECT_WUNLOCK(object); 1561 vm_page_busy_sleep(p, "vmocol", false); 1562 } 1563 VM_OBJECT_WLOCK(object); 1564 VM_OBJECT_WLOCK(backing_object); 1565 return (TAILQ_FIRST(&backing_object->memq)); 1566 } 1567 1568 static bool 1569 vm_object_scan_all_shadowed(vm_object_t object) 1570 { 1571 vm_object_t backing_object; 1572 vm_page_t p, pp; 1573 vm_pindex_t backing_offset_index, new_pindex, pi, ps; 1574 1575 VM_OBJECT_ASSERT_WLOCKED(object); 1576 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1577 1578 backing_object = object->backing_object; 1579 1580 if ((backing_object->flags & OBJ_ANON) == 0) 1581 return (false); 1582 1583 pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1584 p = vm_page_find_least(backing_object, pi); 1585 ps = swap_pager_find_least(backing_object, pi); 1586 1587 /* 1588 * Only check pages inside the parent object's range and 1589 * inside the parent object's mapping of the backing object. 1590 */ 1591 for (;; pi++) { 1592 if (p != NULL && p->pindex < pi) 1593 p = TAILQ_NEXT(p, listq); 1594 if (ps < pi) 1595 ps = swap_pager_find_least(backing_object, pi); 1596 if (p == NULL && ps >= backing_object->size) 1597 break; 1598 else if (p == NULL) 1599 pi = ps; 1600 else 1601 pi = MIN(p->pindex, ps); 1602 1603 new_pindex = pi - backing_offset_index; 1604 if (new_pindex >= object->size) 1605 break; 1606 1607 /* 1608 * See if the parent has the page or if the parent's object 1609 * pager has the page. If the parent has the page but the page 1610 * is not valid, the parent's object pager must have the page. 1611 * 1612 * If this fails, the parent does not completely shadow the 1613 * object and we might as well give up now. 1614 */ 1615 pp = vm_page_lookup(object, new_pindex); 1616 /* 1617 * The valid check here is stable due to object lock being 1618 * required to clear valid and initiate paging. 1619 */ 1620 if ((pp == NULL || vm_page_none_valid(pp)) && 1621 !vm_pager_has_page(object, new_pindex, NULL, NULL)) 1622 return (false); 1623 } 1624 return (true); 1625 } 1626 1627 static bool 1628 vm_object_collapse_scan(vm_object_t object, int op) 1629 { 1630 vm_object_t backing_object; 1631 vm_page_t next, p, pp; 1632 vm_pindex_t backing_offset_index, new_pindex; 1633 1634 VM_OBJECT_ASSERT_WLOCKED(object); 1635 VM_OBJECT_ASSERT_WLOCKED(object->backing_object); 1636 1637 backing_object = object->backing_object; 1638 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1639 1640 /* 1641 * Initial conditions 1642 */ 1643 if ((op & OBSC_COLLAPSE_WAIT) != 0) 1644 vm_object_set_flag(backing_object, OBJ_DEAD); 1645 1646 /* 1647 * Our scan 1648 */ 1649 for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) { 1650 next = TAILQ_NEXT(p, listq); 1651 new_pindex = p->pindex - backing_offset_index; 1652 1653 /* 1654 * Check for busy page 1655 */ 1656 if (vm_page_tryxbusy(p) == 0) { 1657 next = vm_object_collapse_scan_wait(object, p, next, op); 1658 continue; 1659 } 1660 1661 KASSERT(p->object == backing_object, 1662 ("vm_object_collapse_scan: object mismatch")); 1663 1664 if (p->pindex < backing_offset_index || 1665 new_pindex >= object->size) { 1666 if (backing_object->type == OBJT_SWAP) 1667 swap_pager_freespace(backing_object, p->pindex, 1668 1); 1669 1670 KASSERT(!pmap_page_is_mapped(p), 1671 ("freeing mapped page %p", p)); 1672 if (vm_page_remove(p)) 1673 vm_page_free(p); 1674 continue; 1675 } 1676 1677 pp = vm_page_lookup(object, new_pindex); 1678 if (pp != NULL && vm_page_tryxbusy(pp) == 0) { 1679 vm_page_xunbusy(p); 1680 /* 1681 * The page in the parent is busy and possibly not 1682 * (yet) valid. Until its state is finalized by the 1683 * busy bit owner, we can't tell whether it shadows the 1684 * original page. Therefore, we must either skip it 1685 * and the original (backing_object) page or wait for 1686 * its state to be finalized. 1687 * 1688 * This is due to a race with vm_fault() where we must 1689 * unbusy the original (backing_obj) page before we can 1690 * (re)lock the parent. Hence we can get here. 1691 */ 1692 next = vm_object_collapse_scan_wait(object, pp, next, 1693 op); 1694 continue; 1695 } 1696 1697 if (pp != NULL && vm_page_none_valid(pp)) { 1698 /* 1699 * The page was invalid in the parent. Likely placed 1700 * there by an incomplete fault. Just remove and 1701 * ignore. p can replace it. 1702 */ 1703 if (vm_page_remove(pp)) 1704 vm_page_free(pp); 1705 pp = NULL; 1706 } 1707 1708 if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL, 1709 NULL)) { 1710 /* 1711 * The page already exists in the parent OR swap exists 1712 * for this location in the parent. Leave the parent's 1713 * page alone. Destroy the original page from the 1714 * backing object. 1715 */ 1716 if (backing_object->type == OBJT_SWAP) 1717 swap_pager_freespace(backing_object, p->pindex, 1718 1); 1719 KASSERT(!pmap_page_is_mapped(p), 1720 ("freeing mapped page %p", p)); 1721 if (vm_page_remove(p)) 1722 vm_page_free(p); 1723 if (pp != NULL) 1724 vm_page_xunbusy(pp); 1725 continue; 1726 } 1727 1728 /* 1729 * Page does not exist in parent, rename the page from the 1730 * backing object to the main object. 1731 * 1732 * If the page was mapped to a process, it can remain mapped 1733 * through the rename. vm_page_rename() will dirty the page. 1734 */ 1735 if (vm_page_rename(p, object, new_pindex)) { 1736 vm_page_xunbusy(p); 1737 if (pp != NULL) 1738 vm_page_xunbusy(pp); 1739 next = vm_object_collapse_scan_wait(object, NULL, next, 1740 op); 1741 continue; 1742 } 1743 1744 /* Use the old pindex to free the right page. */ 1745 if (backing_object->type == OBJT_SWAP) 1746 swap_pager_freespace(backing_object, 1747 new_pindex + backing_offset_index, 1); 1748 1749 #if VM_NRESERVLEVEL > 0 1750 /* 1751 * Rename the reservation. 1752 */ 1753 vm_reserv_rename(p, object, backing_object, 1754 backing_offset_index); 1755 #endif 1756 vm_page_xunbusy(p); 1757 } 1758 return (true); 1759 } 1760 1761 1762 /* 1763 * this version of collapse allows the operation to occur earlier and 1764 * when paging_in_progress is true for an object... This is not a complete 1765 * operation, but should plug 99.9% of the rest of the leaks. 1766 */ 1767 static void 1768 vm_object_qcollapse(vm_object_t object) 1769 { 1770 vm_object_t backing_object = object->backing_object; 1771 1772 VM_OBJECT_ASSERT_WLOCKED(object); 1773 VM_OBJECT_ASSERT_WLOCKED(backing_object); 1774 1775 if (backing_object->ref_count != 1) 1776 return; 1777 1778 vm_object_collapse_scan(object, OBSC_COLLAPSE_NOWAIT); 1779 } 1780 1781 /* 1782 * vm_object_collapse: 1783 * 1784 * Collapse an object with the object backing it. 1785 * Pages in the backing object are moved into the 1786 * parent, and the backing object is deallocated. 1787 */ 1788 void 1789 vm_object_collapse(vm_object_t object) 1790 { 1791 vm_object_t backing_object, new_backing_object; 1792 1793 VM_OBJECT_ASSERT_WLOCKED(object); 1794 1795 while (TRUE) { 1796 /* 1797 * Verify that the conditions are right for collapse: 1798 * 1799 * The object exists and the backing object exists. 1800 */ 1801 if ((backing_object = object->backing_object) == NULL) 1802 break; 1803 1804 /* 1805 * we check the backing object first, because it is most likely 1806 * not collapsable. 1807 */ 1808 if ((backing_object->flags & OBJ_ANON) == 0) 1809 break; 1810 VM_OBJECT_WLOCK(backing_object); 1811 if ((backing_object->flags & OBJ_DEAD) != 0 || 1812 (object->flags & (OBJ_DEAD | OBJ_ANON)) != OBJ_ANON) { 1813 VM_OBJECT_WUNLOCK(backing_object); 1814 break; 1815 } 1816 1817 if (REFCOUNT_COUNT(object->paging_in_progress) > 0 || 1818 REFCOUNT_COUNT(backing_object->paging_in_progress) > 0) { 1819 vm_object_qcollapse(object); 1820 VM_OBJECT_WUNLOCK(backing_object); 1821 break; 1822 } 1823 1824 /* 1825 * We know that we can either collapse the backing object (if 1826 * the parent is the only reference to it) or (perhaps) have 1827 * the parent bypass the object if the parent happens to shadow 1828 * all the resident pages in the entire backing object. 1829 * 1830 * This is ignoring pager-backed pages such as swap pages. 1831 * vm_object_collapse_scan fails the shadowing test in this 1832 * case. 1833 */ 1834 if (backing_object->ref_count == 1) { 1835 vm_object_pip_add(object, 1); 1836 vm_object_pip_add(backing_object, 1); 1837 1838 /* 1839 * If there is exactly one reference to the backing 1840 * object, we can collapse it into the parent. 1841 */ 1842 vm_object_collapse_scan(object, OBSC_COLLAPSE_WAIT); 1843 1844 #if VM_NRESERVLEVEL > 0 1845 /* 1846 * Break any reservations from backing_object. 1847 */ 1848 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1849 vm_reserv_break_all(backing_object); 1850 #endif 1851 1852 /* 1853 * Move the pager from backing_object to object. 1854 */ 1855 if (backing_object->type == OBJT_SWAP) { 1856 /* 1857 * swap_pager_copy() can sleep, in which case 1858 * the backing_object's and object's locks are 1859 * released and reacquired. 1860 * Since swap_pager_copy() is being asked to 1861 * destroy the source, it will change the 1862 * backing_object's type to OBJT_DEFAULT. 1863 */ 1864 swap_pager_copy( 1865 backing_object, 1866 object, 1867 OFF_TO_IDX(object->backing_object_offset), TRUE); 1868 } 1869 /* 1870 * Object now shadows whatever backing_object did. 1871 * Note that the reference to 1872 * backing_object->backing_object moves from within 1873 * backing_object to within object. 1874 */ 1875 vm_object_backing_remove_locked(object); 1876 new_backing_object = backing_object->backing_object; 1877 if (new_backing_object != NULL) { 1878 VM_OBJECT_WLOCK(new_backing_object); 1879 vm_object_backing_remove_locked(backing_object); 1880 vm_object_backing_insert_locked(object, 1881 new_backing_object); 1882 VM_OBJECT_WUNLOCK(new_backing_object); 1883 } 1884 object->backing_object_offset += 1885 backing_object->backing_object_offset; 1886 1887 /* 1888 * Discard backing_object. 1889 * 1890 * Since the backing object has no pages, no pager left, 1891 * and no object references within it, all that is 1892 * necessary is to dispose of it. 1893 */ 1894 KASSERT(backing_object->ref_count == 1, ( 1895 "backing_object %p was somehow re-referenced during collapse!", 1896 backing_object)); 1897 vm_object_pip_wakeup(backing_object); 1898 backing_object->type = OBJT_DEAD; 1899 refcount_release(&backing_object->ref_count); 1900 VM_OBJECT_WUNLOCK(backing_object); 1901 vm_object_destroy(backing_object); 1902 1903 vm_object_pip_wakeup(object); 1904 counter_u64_add(object_collapses, 1); 1905 } else { 1906 /* 1907 * If we do not entirely shadow the backing object, 1908 * there is nothing we can do so we give up. 1909 */ 1910 if (object->resident_page_count != object->size && 1911 !vm_object_scan_all_shadowed(object)) { 1912 VM_OBJECT_WUNLOCK(backing_object); 1913 break; 1914 } 1915 1916 /* 1917 * Make the parent shadow the next object in the 1918 * chain. Deallocating backing_object will not remove 1919 * it, since its reference count is at least 2. 1920 */ 1921 vm_object_backing_remove_locked(object); 1922 1923 new_backing_object = backing_object->backing_object; 1924 if (new_backing_object != NULL) { 1925 vm_object_backing_insert(object, 1926 new_backing_object); 1927 vm_object_reference(new_backing_object); 1928 object->backing_object_offset += 1929 backing_object->backing_object_offset; 1930 } 1931 1932 /* 1933 * Drop the reference count on backing_object. Since 1934 * its ref_count was at least 2, it will not vanish. 1935 */ 1936 refcount_release(&backing_object->ref_count); 1937 VM_OBJECT_WUNLOCK(backing_object); 1938 counter_u64_add(object_bypasses, 1); 1939 } 1940 1941 /* 1942 * Try again with this object's new backing object. 1943 */ 1944 } 1945 } 1946 1947 /* 1948 * vm_object_page_remove: 1949 * 1950 * For the given object, either frees or invalidates each of the 1951 * specified pages. In general, a page is freed. However, if a page is 1952 * wired for any reason other than the existence of a managed, wired 1953 * mapping, then it may be invalidated but not removed from the object. 1954 * Pages are specified by the given range ["start", "end") and the option 1955 * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range 1956 * extends from "start" to the end of the object. If the option 1957 * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the 1958 * specified range are affected. If the option OBJPR_NOTMAPPED is 1959 * specified, then the pages within the specified range must have no 1960 * mappings. Otherwise, if this option is not specified, any mappings to 1961 * the specified pages are removed before the pages are freed or 1962 * invalidated. 1963 * 1964 * In general, this operation should only be performed on objects that 1965 * contain managed pages. There are, however, two exceptions. First, it 1966 * is performed on the kernel and kmem objects by vm_map_entry_delete(). 1967 * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device- 1968 * backed pages. In both of these cases, the option OBJPR_CLEANONLY must 1969 * not be specified and the option OBJPR_NOTMAPPED must be specified. 1970 * 1971 * The object must be locked. 1972 */ 1973 void 1974 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1975 int options) 1976 { 1977 vm_page_t p, next; 1978 1979 VM_OBJECT_ASSERT_WLOCKED(object); 1980 KASSERT((object->flags & OBJ_UNMANAGED) == 0 || 1981 (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED, 1982 ("vm_object_page_remove: illegal options for object %p", object)); 1983 if (object->resident_page_count == 0) 1984 return; 1985 vm_object_pip_add(object, 1); 1986 again: 1987 p = vm_page_find_least(object, start); 1988 1989 /* 1990 * Here, the variable "p" is either (1) the page with the least pindex 1991 * greater than or equal to the parameter "start" or (2) NULL. 1992 */ 1993 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 1994 next = TAILQ_NEXT(p, listq); 1995 1996 /* 1997 * If the page is wired for any reason besides the existence 1998 * of managed, wired mappings, then it cannot be freed. For 1999 * example, fictitious pages, which represent device memory, 2000 * are inherently wired and cannot be freed. They can, 2001 * however, be invalidated if the option OBJPR_CLEANONLY is 2002 * not specified. 2003 */ 2004 if (vm_page_tryxbusy(p) == 0) { 2005 vm_page_sleep_if_busy(p, "vmopar"); 2006 goto again; 2007 } 2008 if (vm_page_wired(p)) { 2009 wired: 2010 if ((options & OBJPR_NOTMAPPED) == 0 && 2011 object->ref_count != 0) 2012 pmap_remove_all(p); 2013 if ((options & OBJPR_CLEANONLY) == 0) { 2014 vm_page_invalid(p); 2015 vm_page_undirty(p); 2016 } 2017 vm_page_xunbusy(p); 2018 continue; 2019 } 2020 KASSERT((p->flags & PG_FICTITIOUS) == 0, 2021 ("vm_object_page_remove: page %p is fictitious", p)); 2022 if ((options & OBJPR_CLEANONLY) != 0 && 2023 !vm_page_none_valid(p)) { 2024 if ((options & OBJPR_NOTMAPPED) == 0 && 2025 object->ref_count != 0 && 2026 !vm_page_try_remove_write(p)) 2027 goto wired; 2028 if (p->dirty != 0) { 2029 vm_page_xunbusy(p); 2030 continue; 2031 } 2032 } 2033 if ((options & OBJPR_NOTMAPPED) == 0 && 2034 object->ref_count != 0 && !vm_page_try_remove_all(p)) 2035 goto wired; 2036 vm_page_free(p); 2037 } 2038 vm_object_pip_wakeup(object); 2039 } 2040 2041 /* 2042 * vm_object_page_noreuse: 2043 * 2044 * For the given object, attempt to move the specified pages to 2045 * the head of the inactive queue. This bypasses regular LRU 2046 * operation and allows the pages to be reused quickly under memory 2047 * pressure. If a page is wired for any reason, then it will not 2048 * be queued. Pages are specified by the range ["start", "end"). 2049 * As a special case, if "end" is zero, then the range extends from 2050 * "start" to the end of the object. 2051 * 2052 * This operation should only be performed on objects that 2053 * contain non-fictitious, managed pages. 2054 * 2055 * The object must be locked. 2056 */ 2057 void 2058 vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2059 { 2060 vm_page_t p, next; 2061 2062 VM_OBJECT_ASSERT_LOCKED(object); 2063 KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0, 2064 ("vm_object_page_noreuse: illegal object %p", object)); 2065 if (object->resident_page_count == 0) 2066 return; 2067 p = vm_page_find_least(object, start); 2068 2069 /* 2070 * Here, the variable "p" is either (1) the page with the least pindex 2071 * greater than or equal to the parameter "start" or (2) NULL. 2072 */ 2073 for (; p != NULL && (p->pindex < end || end == 0); p = next) { 2074 next = TAILQ_NEXT(p, listq); 2075 vm_page_deactivate_noreuse(p); 2076 } 2077 } 2078 2079 /* 2080 * Populate the specified range of the object with valid pages. Returns 2081 * TRUE if the range is successfully populated and FALSE otherwise. 2082 * 2083 * Note: This function should be optimized to pass a larger array of 2084 * pages to vm_pager_get_pages() before it is applied to a non- 2085 * OBJT_DEVICE object. 2086 * 2087 * The object must be locked. 2088 */ 2089 boolean_t 2090 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 2091 { 2092 vm_page_t m; 2093 vm_pindex_t pindex; 2094 int rv; 2095 2096 VM_OBJECT_ASSERT_WLOCKED(object); 2097 for (pindex = start; pindex < end; pindex++) { 2098 rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL); 2099 if (rv != VM_PAGER_OK) 2100 break; 2101 2102 /* 2103 * Keep "m" busy because a subsequent iteration may unlock 2104 * the object. 2105 */ 2106 } 2107 if (pindex > start) { 2108 m = vm_page_lookup(object, start); 2109 while (m != NULL && m->pindex < pindex) { 2110 vm_page_xunbusy(m); 2111 m = TAILQ_NEXT(m, listq); 2112 } 2113 } 2114 return (pindex == end); 2115 } 2116 2117 /* 2118 * Routine: vm_object_coalesce 2119 * Function: Coalesces two objects backing up adjoining 2120 * regions of memory into a single object. 2121 * 2122 * returns TRUE if objects were combined. 2123 * 2124 * NOTE: Only works at the moment if the second object is NULL - 2125 * if it's not, which object do we lock first? 2126 * 2127 * Parameters: 2128 * prev_object First object to coalesce 2129 * prev_offset Offset into prev_object 2130 * prev_size Size of reference to prev_object 2131 * next_size Size of reference to the second object 2132 * reserved Indicator that extension region has 2133 * swap accounted for 2134 * 2135 * Conditions: 2136 * The object must *not* be locked. 2137 */ 2138 boolean_t 2139 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2140 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2141 { 2142 vm_pindex_t next_pindex; 2143 2144 if (prev_object == NULL) 2145 return (TRUE); 2146 if ((prev_object->flags & OBJ_ANON) == 0) 2147 return (FALSE); 2148 2149 VM_OBJECT_WLOCK(prev_object); 2150 /* 2151 * Try to collapse the object first 2152 */ 2153 vm_object_collapse(prev_object); 2154 2155 /* 2156 * Can't coalesce if: . more than one reference . paged out . shadows 2157 * another object . has a copy elsewhere (any of which mean that the 2158 * pages not mapped to prev_entry may be in use anyway) 2159 */ 2160 if (prev_object->backing_object != NULL) { 2161 VM_OBJECT_WUNLOCK(prev_object); 2162 return (FALSE); 2163 } 2164 2165 prev_size >>= PAGE_SHIFT; 2166 next_size >>= PAGE_SHIFT; 2167 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2168 2169 if (prev_object->ref_count > 1 && 2170 prev_object->size != next_pindex && 2171 (prev_object->flags & OBJ_ONEMAPPING) == 0) { 2172 VM_OBJECT_WUNLOCK(prev_object); 2173 return (FALSE); 2174 } 2175 2176 /* 2177 * Account for the charge. 2178 */ 2179 if (prev_object->cred != NULL) { 2180 2181 /* 2182 * If prev_object was charged, then this mapping, 2183 * although not charged now, may become writable 2184 * later. Non-NULL cred in the object would prevent 2185 * swap reservation during enabling of the write 2186 * access, so reserve swap now. Failed reservation 2187 * cause allocation of the separate object for the map 2188 * entry, and swap reservation for this entry is 2189 * managed in appropriate time. 2190 */ 2191 if (!reserved && !swap_reserve_by_cred(ptoa(next_size), 2192 prev_object->cred)) { 2193 VM_OBJECT_WUNLOCK(prev_object); 2194 return (FALSE); 2195 } 2196 prev_object->charge += ptoa(next_size); 2197 } 2198 2199 /* 2200 * Remove any pages that may still be in the object from a previous 2201 * deallocation. 2202 */ 2203 if (next_pindex < prev_object->size) { 2204 vm_object_page_remove(prev_object, next_pindex, next_pindex + 2205 next_size, 0); 2206 if (prev_object->type == OBJT_SWAP) 2207 swap_pager_freespace(prev_object, 2208 next_pindex, next_size); 2209 #if 0 2210 if (prev_object->cred != NULL) { 2211 KASSERT(prev_object->charge >= 2212 ptoa(prev_object->size - next_pindex), 2213 ("object %p overcharged 1 %jx %jx", prev_object, 2214 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2215 prev_object->charge -= ptoa(prev_object->size - 2216 next_pindex); 2217 } 2218 #endif 2219 } 2220 2221 /* 2222 * Extend the object if necessary. 2223 */ 2224 if (next_pindex + next_size > prev_object->size) 2225 prev_object->size = next_pindex + next_size; 2226 2227 VM_OBJECT_WUNLOCK(prev_object); 2228 return (TRUE); 2229 } 2230 2231 void 2232 vm_object_set_writeable_dirty(vm_object_t object) 2233 { 2234 2235 /* Only set for vnodes & tmpfs */ 2236 if (object->type != OBJT_VNODE && 2237 (object->flags & OBJ_TMPFS_NODE) == 0) 2238 return; 2239 atomic_add_int(&object->generation, 1); 2240 } 2241 2242 /* 2243 * vm_object_unwire: 2244 * 2245 * For each page offset within the specified range of the given object, 2246 * find the highest-level page in the shadow chain and unwire it. A page 2247 * must exist at every page offset, and the highest-level page must be 2248 * wired. 2249 */ 2250 void 2251 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length, 2252 uint8_t queue) 2253 { 2254 vm_object_t tobject, t1object; 2255 vm_page_t m, tm; 2256 vm_pindex_t end_pindex, pindex, tpindex; 2257 int depth, locked_depth; 2258 2259 KASSERT((offset & PAGE_MASK) == 0, 2260 ("vm_object_unwire: offset is not page aligned")); 2261 KASSERT((length & PAGE_MASK) == 0, 2262 ("vm_object_unwire: length is not a multiple of PAGE_SIZE")); 2263 /* The wired count of a fictitious page never changes. */ 2264 if ((object->flags & OBJ_FICTITIOUS) != 0) 2265 return; 2266 pindex = OFF_TO_IDX(offset); 2267 end_pindex = pindex + atop(length); 2268 again: 2269 locked_depth = 1; 2270 VM_OBJECT_RLOCK(object); 2271 m = vm_page_find_least(object, pindex); 2272 while (pindex < end_pindex) { 2273 if (m == NULL || pindex < m->pindex) { 2274 /* 2275 * The first object in the shadow chain doesn't 2276 * contain a page at the current index. Therefore, 2277 * the page must exist in a backing object. 2278 */ 2279 tobject = object; 2280 tpindex = pindex; 2281 depth = 0; 2282 do { 2283 tpindex += 2284 OFF_TO_IDX(tobject->backing_object_offset); 2285 tobject = tobject->backing_object; 2286 KASSERT(tobject != NULL, 2287 ("vm_object_unwire: missing page")); 2288 if ((tobject->flags & OBJ_FICTITIOUS) != 0) 2289 goto next_page; 2290 depth++; 2291 if (depth == locked_depth) { 2292 locked_depth++; 2293 VM_OBJECT_RLOCK(tobject); 2294 } 2295 } while ((tm = vm_page_lookup(tobject, tpindex)) == 2296 NULL); 2297 } else { 2298 tm = m; 2299 m = TAILQ_NEXT(m, listq); 2300 } 2301 if (vm_page_trysbusy(tm) == 0) { 2302 for (tobject = object; locked_depth >= 1; 2303 locked_depth--) { 2304 t1object = tobject->backing_object; 2305 if (tm->object != tobject) 2306 VM_OBJECT_RUNLOCK(tobject); 2307 tobject = t1object; 2308 } 2309 vm_page_busy_sleep(tm, "unwbo", true); 2310 goto again; 2311 } 2312 vm_page_unwire(tm, queue); 2313 vm_page_sunbusy(tm); 2314 next_page: 2315 pindex++; 2316 } 2317 /* Release the accumulated object locks. */ 2318 for (tobject = object; locked_depth >= 1; locked_depth--) { 2319 t1object = tobject->backing_object; 2320 VM_OBJECT_RUNLOCK(tobject); 2321 tobject = t1object; 2322 } 2323 } 2324 2325 /* 2326 * Return the vnode for the given object, or NULL if none exists. 2327 * For tmpfs objects, the function may return NULL if there is 2328 * no vnode allocated at the time of the call. 2329 */ 2330 struct vnode * 2331 vm_object_vnode(vm_object_t object) 2332 { 2333 struct vnode *vp; 2334 2335 VM_OBJECT_ASSERT_LOCKED(object); 2336 if (object->type == OBJT_VNODE) { 2337 vp = object->handle; 2338 KASSERT(vp != NULL, ("%s: OBJT_VNODE has no vnode", __func__)); 2339 } else if (object->type == OBJT_SWAP && 2340 (object->flags & OBJ_TMPFS) != 0) { 2341 vp = object->un_pager.swp.swp_tmpfs; 2342 KASSERT(vp != NULL, ("%s: OBJT_TMPFS has no vnode", __func__)); 2343 } else { 2344 vp = NULL; 2345 } 2346 return (vp); 2347 } 2348 2349 2350 /* 2351 * Busy the vm object. This prevents new pages belonging to the object from 2352 * becoming busy. Existing pages persist as busy. Callers are responsible 2353 * for checking page state before proceeding. 2354 */ 2355 void 2356 vm_object_busy(vm_object_t obj) 2357 { 2358 2359 VM_OBJECT_ASSERT_LOCKED(obj); 2360 2361 refcount_acquire(&obj->busy); 2362 /* The fence is required to order loads of page busy. */ 2363 atomic_thread_fence_acq_rel(); 2364 } 2365 2366 void 2367 vm_object_unbusy(vm_object_t obj) 2368 { 2369 2370 2371 refcount_release(&obj->busy); 2372 } 2373 2374 void 2375 vm_object_busy_wait(vm_object_t obj, const char *wmesg) 2376 { 2377 2378 VM_OBJECT_ASSERT_UNLOCKED(obj); 2379 2380 if (obj->busy) 2381 refcount_sleep(&obj->busy, wmesg, PVM); 2382 } 2383 2384 /* 2385 * Return the kvme type of the given object. 2386 * If vpp is not NULL, set it to the object's vm_object_vnode() or NULL. 2387 */ 2388 int 2389 vm_object_kvme_type(vm_object_t object, struct vnode **vpp) 2390 { 2391 2392 VM_OBJECT_ASSERT_LOCKED(object); 2393 if (vpp != NULL) 2394 *vpp = vm_object_vnode(object); 2395 switch (object->type) { 2396 case OBJT_DEFAULT: 2397 return (KVME_TYPE_DEFAULT); 2398 case OBJT_VNODE: 2399 return (KVME_TYPE_VNODE); 2400 case OBJT_SWAP: 2401 if ((object->flags & OBJ_TMPFS_NODE) != 0) 2402 return (KVME_TYPE_VNODE); 2403 return (KVME_TYPE_SWAP); 2404 case OBJT_DEVICE: 2405 return (KVME_TYPE_DEVICE); 2406 case OBJT_PHYS: 2407 return (KVME_TYPE_PHYS); 2408 case OBJT_DEAD: 2409 return (KVME_TYPE_DEAD); 2410 case OBJT_SG: 2411 return (KVME_TYPE_SG); 2412 case OBJT_MGTDEVICE: 2413 return (KVME_TYPE_MGTDEVICE); 2414 default: 2415 return (KVME_TYPE_UNKNOWN); 2416 } 2417 } 2418 2419 static int 2420 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS) 2421 { 2422 struct kinfo_vmobject *kvo; 2423 char *fullpath, *freepath; 2424 struct vnode *vp; 2425 struct vattr va; 2426 vm_object_t obj; 2427 vm_page_t m; 2428 int count, error; 2429 2430 if (req->oldptr == NULL) { 2431 /* 2432 * If an old buffer has not been provided, generate an 2433 * estimate of the space needed for a subsequent call. 2434 */ 2435 mtx_lock(&vm_object_list_mtx); 2436 count = 0; 2437 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2438 if (obj->type == OBJT_DEAD) 2439 continue; 2440 count++; 2441 } 2442 mtx_unlock(&vm_object_list_mtx); 2443 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) * 2444 count * 11 / 10)); 2445 } 2446 2447 kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK); 2448 error = 0; 2449 2450 /* 2451 * VM objects are type stable and are never removed from the 2452 * list once added. This allows us to safely read obj->object_list 2453 * after reacquiring the VM object lock. 2454 */ 2455 mtx_lock(&vm_object_list_mtx); 2456 TAILQ_FOREACH(obj, &vm_object_list, object_list) { 2457 if (obj->type == OBJT_DEAD) 2458 continue; 2459 VM_OBJECT_RLOCK(obj); 2460 if (obj->type == OBJT_DEAD) { 2461 VM_OBJECT_RUNLOCK(obj); 2462 continue; 2463 } 2464 mtx_unlock(&vm_object_list_mtx); 2465 kvo->kvo_size = ptoa(obj->size); 2466 kvo->kvo_resident = obj->resident_page_count; 2467 kvo->kvo_ref_count = obj->ref_count; 2468 kvo->kvo_shadow_count = obj->shadow_count; 2469 kvo->kvo_memattr = obj->memattr; 2470 kvo->kvo_active = 0; 2471 kvo->kvo_inactive = 0; 2472 TAILQ_FOREACH(m, &obj->memq, listq) { 2473 /* 2474 * A page may belong to the object but be 2475 * dequeued and set to PQ_NONE while the 2476 * object lock is not held. This makes the 2477 * reads of m->queue below racy, and we do not 2478 * count pages set to PQ_NONE. However, this 2479 * sysctl is only meant to give an 2480 * approximation of the system anyway. 2481 */ 2482 if (m->a.queue == PQ_ACTIVE) 2483 kvo->kvo_active++; 2484 else if (m->a.queue == PQ_INACTIVE) 2485 kvo->kvo_inactive++; 2486 } 2487 2488 kvo->kvo_vn_fileid = 0; 2489 kvo->kvo_vn_fsid = 0; 2490 kvo->kvo_vn_fsid_freebsd11 = 0; 2491 freepath = NULL; 2492 fullpath = ""; 2493 kvo->kvo_type = vm_object_kvme_type(obj, &vp); 2494 if (vp != NULL) 2495 vref(vp); 2496 VM_OBJECT_RUNLOCK(obj); 2497 if (vp != NULL) { 2498 vn_fullpath(curthread, vp, &fullpath, &freepath); 2499 vn_lock(vp, LK_SHARED | LK_RETRY); 2500 if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) { 2501 kvo->kvo_vn_fileid = va.va_fileid; 2502 kvo->kvo_vn_fsid = va.va_fsid; 2503 kvo->kvo_vn_fsid_freebsd11 = va.va_fsid; 2504 /* truncate */ 2505 } 2506 vput(vp); 2507 } 2508 2509 strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path)); 2510 if (freepath != NULL) 2511 free(freepath, M_TEMP); 2512 2513 /* Pack record size down */ 2514 kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path) 2515 + strlen(kvo->kvo_path) + 1; 2516 kvo->kvo_structsize = roundup(kvo->kvo_structsize, 2517 sizeof(uint64_t)); 2518 error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize); 2519 mtx_lock(&vm_object_list_mtx); 2520 if (error) 2521 break; 2522 } 2523 mtx_unlock(&vm_object_list_mtx); 2524 free(kvo, M_TEMP); 2525 return (error); 2526 } 2527 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | 2528 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject", 2529 "List of VM objects"); 2530 2531 #include "opt_ddb.h" 2532 #ifdef DDB 2533 #include <sys/kernel.h> 2534 2535 #include <sys/cons.h> 2536 2537 #include <ddb/ddb.h> 2538 2539 static int 2540 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2541 { 2542 vm_map_t tmpm; 2543 vm_map_entry_t tmpe; 2544 vm_object_t obj; 2545 2546 if (map == 0) 2547 return 0; 2548 2549 if (entry == 0) { 2550 VM_MAP_ENTRY_FOREACH(tmpe, map) { 2551 if (_vm_object_in_map(map, object, tmpe)) { 2552 return 1; 2553 } 2554 } 2555 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2556 tmpm = entry->object.sub_map; 2557 VM_MAP_ENTRY_FOREACH(tmpe, tmpm) { 2558 if (_vm_object_in_map(tmpm, object, tmpe)) { 2559 return 1; 2560 } 2561 } 2562 } else if ((obj = entry->object.vm_object) != NULL) { 2563 for (; obj; obj = obj->backing_object) 2564 if (obj == object) { 2565 return 1; 2566 } 2567 } 2568 return 0; 2569 } 2570 2571 static int 2572 vm_object_in_map(vm_object_t object) 2573 { 2574 struct proc *p; 2575 2576 /* sx_slock(&allproc_lock); */ 2577 FOREACH_PROC_IN_SYSTEM(p) { 2578 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2579 continue; 2580 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2581 /* sx_sunlock(&allproc_lock); */ 2582 return 1; 2583 } 2584 } 2585 /* sx_sunlock(&allproc_lock); */ 2586 if (_vm_object_in_map(kernel_map, object, 0)) 2587 return 1; 2588 return 0; 2589 } 2590 2591 DB_SHOW_COMMAND(vmochk, vm_object_check) 2592 { 2593 vm_object_t object; 2594 2595 /* 2596 * make sure that internal objs are in a map somewhere 2597 * and none have zero ref counts. 2598 */ 2599 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2600 if ((object->flags & OBJ_ANON) != 0) { 2601 if (object->ref_count == 0) { 2602 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2603 (long)object->size); 2604 } 2605 if (!vm_object_in_map(object)) { 2606 db_printf( 2607 "vmochk: internal obj is not in a map: " 2608 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2609 object->ref_count, (u_long)object->size, 2610 (u_long)object->size, 2611 (void *)object->backing_object); 2612 } 2613 } 2614 } 2615 } 2616 2617 /* 2618 * vm_object_print: [ debug ] 2619 */ 2620 DB_SHOW_COMMAND(object, vm_object_print_static) 2621 { 2622 /* XXX convert args. */ 2623 vm_object_t object = (vm_object_t)addr; 2624 boolean_t full = have_addr; 2625 2626 vm_page_t p; 2627 2628 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2629 #define count was_count 2630 2631 int count; 2632 2633 if (object == NULL) 2634 return; 2635 2636 db_iprintf( 2637 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n", 2638 object, (int)object->type, (uintmax_t)object->size, 2639 object->resident_page_count, object->ref_count, object->flags, 2640 object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge); 2641 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2642 object->shadow_count, 2643 object->backing_object ? object->backing_object->ref_count : 0, 2644 object->backing_object, (uintmax_t)object->backing_object_offset); 2645 2646 if (!full) 2647 return; 2648 2649 db_indent += 2; 2650 count = 0; 2651 TAILQ_FOREACH(p, &object->memq, listq) { 2652 if (count == 0) 2653 db_iprintf("memory:="); 2654 else if (count == 6) { 2655 db_printf("\n"); 2656 db_iprintf(" ..."); 2657 count = 0; 2658 } else 2659 db_printf(","); 2660 count++; 2661 2662 db_printf("(off=0x%jx,page=0x%jx)", 2663 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2664 } 2665 if (count != 0) 2666 db_printf("\n"); 2667 db_indent -= 2; 2668 } 2669 2670 /* XXX. */ 2671 #undef count 2672 2673 /* XXX need this non-static entry for calling from vm_map_print. */ 2674 void 2675 vm_object_print( 2676 /* db_expr_t */ long addr, 2677 boolean_t have_addr, 2678 /* db_expr_t */ long count, 2679 char *modif) 2680 { 2681 vm_object_print_static(addr, have_addr, count, modif); 2682 } 2683 2684 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2685 { 2686 vm_object_t object; 2687 vm_pindex_t fidx; 2688 vm_paddr_t pa; 2689 vm_page_t m, prev_m; 2690 int rcount, nl, c; 2691 2692 nl = 0; 2693 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2694 db_printf("new object: %p\n", (void *)object); 2695 if (nl > 18) { 2696 c = cngetc(); 2697 if (c != ' ') 2698 return; 2699 nl = 0; 2700 } 2701 nl++; 2702 rcount = 0; 2703 fidx = 0; 2704 pa = -1; 2705 TAILQ_FOREACH(m, &object->memq, listq) { 2706 if (m->pindex > 128) 2707 break; 2708 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2709 prev_m->pindex + 1 != m->pindex) { 2710 if (rcount) { 2711 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2712 (long)fidx, rcount, (long)pa); 2713 if (nl > 18) { 2714 c = cngetc(); 2715 if (c != ' ') 2716 return; 2717 nl = 0; 2718 } 2719 nl++; 2720 rcount = 0; 2721 } 2722 } 2723 if (rcount && 2724 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2725 ++rcount; 2726 continue; 2727 } 2728 if (rcount) { 2729 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2730 (long)fidx, rcount, (long)pa); 2731 if (nl > 18) { 2732 c = cngetc(); 2733 if (c != ' ') 2734 return; 2735 nl = 0; 2736 } 2737 nl++; 2738 } 2739 fidx = m->pindex; 2740 pa = VM_PAGE_TO_PHYS(m); 2741 rcount = 1; 2742 } 2743 if (rcount) { 2744 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2745 (long)fidx, rcount, (long)pa); 2746 if (nl > 18) { 2747 c = cngetc(); 2748 if (c != ' ') 2749 return; 2750 nl = 0; 2751 } 2752 nl++; 2753 } 2754 } 2755 } 2756 #endif /* DDB */ 2757