1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Virtual memory object module. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include "opt_vm.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/lock.h> 73 #include <sys/mman.h> 74 #include <sys/mount.h> 75 #include <sys/kernel.h> 76 #include <sys/sysctl.h> 77 #include <sys/mutex.h> 78 #include <sys/proc.h> /* for curproc, pageproc */ 79 #include <sys/socket.h> 80 #include <sys/resourcevar.h> 81 #include <sys/vnode.h> 82 #include <sys/vmmeter.h> 83 #include <sys/sx.h> 84 85 #include <vm/vm.h> 86 #include <vm/vm_param.h> 87 #include <vm/pmap.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_object.h> 90 #include <vm/vm_page.h> 91 #include <vm/vm_pageout.h> 92 #include <vm/vm_pager.h> 93 #include <vm/swap_pager.h> 94 #include <vm/vm_kern.h> 95 #include <vm/vm_extern.h> 96 #include <vm/vm_reserv.h> 97 #include <vm/uma.h> 98 99 #define EASY_SCAN_FACTOR 8 100 101 #define MSYNC_FLUSH_HARDSEQ 0x01 102 #define MSYNC_FLUSH_SOFTSEQ 0x02 103 104 /* 105 * msync / VM object flushing optimizations 106 */ 107 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 108 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, CTLFLAG_RW, &msync_flush_flags, 0, 109 "Enable sequential iteration optimization"); 110 111 static int old_msync; 112 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 113 "Use old (insecure) msync behavior"); 114 115 static void vm_object_qcollapse(vm_object_t object); 116 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 117 static void vm_object_vndeallocate(vm_object_t object); 118 119 /* 120 * Virtual memory objects maintain the actual data 121 * associated with allocated virtual memory. A given 122 * page of memory exists within exactly one object. 123 * 124 * An object is only deallocated when all "references" 125 * are given up. Only one "reference" to a given 126 * region of an object should be writeable. 127 * 128 * Associated with each object is a list of all resident 129 * memory pages belonging to that object; this list is 130 * maintained by the "vm_page" module, and locked by the object's 131 * lock. 132 * 133 * Each object also records a "pager" routine which is 134 * used to retrieve (and store) pages to the proper backing 135 * storage. In addition, objects may be backed by other 136 * objects from which they were virtual-copied. 137 * 138 * The only items within the object structure which are 139 * modified after time of creation are: 140 * reference count locked by object's lock 141 * pager routine locked by object's lock 142 * 143 */ 144 145 struct object_q vm_object_list; 146 struct mtx vm_object_list_mtx; /* lock for object list and count */ 147 148 struct vm_object kernel_object_store; 149 struct vm_object kmem_object_store; 150 151 SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0, "VM object stats"); 152 153 static long object_collapses; 154 SYSCTL_LONG(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, 155 &object_collapses, 0, "VM object collapses"); 156 157 static long object_bypasses; 158 SYSCTL_LONG(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, 159 &object_bypasses, 0, "VM object bypasses"); 160 161 static uma_zone_t obj_zone; 162 163 static int vm_object_zinit(void *mem, int size, int flags); 164 165 #ifdef INVARIANTS 166 static void vm_object_zdtor(void *mem, int size, void *arg); 167 168 static void 169 vm_object_zdtor(void *mem, int size, void *arg) 170 { 171 vm_object_t object; 172 173 object = (vm_object_t)mem; 174 KASSERT(TAILQ_EMPTY(&object->memq), 175 ("object %p has resident pages", 176 object)); 177 #if VM_NRESERVLEVEL > 0 178 KASSERT(LIST_EMPTY(&object->rvq), 179 ("object %p has reservations", 180 object)); 181 #endif 182 KASSERT(object->cache == NULL, 183 ("object %p has cached pages", 184 object)); 185 KASSERT(object->paging_in_progress == 0, 186 ("object %p paging_in_progress = %d", 187 object, object->paging_in_progress)); 188 KASSERT(object->resident_page_count == 0, 189 ("object %p resident_page_count = %d", 190 object, object->resident_page_count)); 191 KASSERT(object->shadow_count == 0, 192 ("object %p shadow_count = %d", 193 object, object->shadow_count)); 194 } 195 #endif 196 197 static int 198 vm_object_zinit(void *mem, int size, int flags) 199 { 200 vm_object_t object; 201 202 object = (vm_object_t)mem; 203 bzero(&object->mtx, sizeof(object->mtx)); 204 VM_OBJECT_LOCK_INIT(object, "standard object"); 205 206 /* These are true for any object that has been freed */ 207 object->paging_in_progress = 0; 208 object->resident_page_count = 0; 209 object->shadow_count = 0; 210 return (0); 211 } 212 213 void 214 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object) 215 { 216 217 TAILQ_INIT(&object->memq); 218 LIST_INIT(&object->shadow_head); 219 220 object->root = NULL; 221 object->type = type; 222 object->size = size; 223 object->generation = 1; 224 object->ref_count = 1; 225 object->flags = 0; 226 object->uip = NULL; 227 object->charge = 0; 228 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 229 object->flags = OBJ_ONEMAPPING; 230 object->pg_color = 0; 231 object->handle = NULL; 232 object->backing_object = NULL; 233 object->backing_object_offset = (vm_ooffset_t) 0; 234 #if VM_NRESERVLEVEL > 0 235 LIST_INIT(&object->rvq); 236 #endif 237 object->cache = NULL; 238 239 mtx_lock(&vm_object_list_mtx); 240 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 241 mtx_unlock(&vm_object_list_mtx); 242 } 243 244 /* 245 * vm_object_init: 246 * 247 * Initialize the VM objects module. 248 */ 249 void 250 vm_object_init(void) 251 { 252 TAILQ_INIT(&vm_object_list); 253 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 254 255 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object"); 256 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 257 kernel_object); 258 #if VM_NRESERVLEVEL > 0 259 kernel_object->flags |= OBJ_COLORED; 260 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 261 #endif 262 263 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object"); 264 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 265 kmem_object); 266 #if VM_NRESERVLEVEL > 0 267 kmem_object->flags |= OBJ_COLORED; 268 kmem_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 269 #endif 270 271 /* 272 * The lock portion of struct vm_object must be type stable due 273 * to vm_pageout_fallback_object_lock locking a vm object 274 * without holding any references to it. 275 */ 276 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 277 #ifdef INVARIANTS 278 vm_object_zdtor, 279 #else 280 NULL, 281 #endif 282 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 283 } 284 285 void 286 vm_object_clear_flag(vm_object_t object, u_short bits) 287 { 288 289 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 290 object->flags &= ~bits; 291 } 292 293 void 294 vm_object_pip_add(vm_object_t object, short i) 295 { 296 297 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 298 object->paging_in_progress += i; 299 } 300 301 void 302 vm_object_pip_subtract(vm_object_t object, short i) 303 { 304 305 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 306 object->paging_in_progress -= i; 307 } 308 309 void 310 vm_object_pip_wakeup(vm_object_t object) 311 { 312 313 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 314 object->paging_in_progress--; 315 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 316 vm_object_clear_flag(object, OBJ_PIPWNT); 317 wakeup(object); 318 } 319 } 320 321 void 322 vm_object_pip_wakeupn(vm_object_t object, short i) 323 { 324 325 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 326 if (i) 327 object->paging_in_progress -= i; 328 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 329 vm_object_clear_flag(object, OBJ_PIPWNT); 330 wakeup(object); 331 } 332 } 333 334 void 335 vm_object_pip_wait(vm_object_t object, char *waitid) 336 { 337 338 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 339 while (object->paging_in_progress) { 340 object->flags |= OBJ_PIPWNT; 341 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 342 } 343 } 344 345 /* 346 * vm_object_allocate: 347 * 348 * Returns a new object with the given size. 349 */ 350 vm_object_t 351 vm_object_allocate(objtype_t type, vm_pindex_t size) 352 { 353 vm_object_t object; 354 355 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 356 _vm_object_allocate(type, size, object); 357 return (object); 358 } 359 360 361 /* 362 * vm_object_reference: 363 * 364 * Gets another reference to the given object. Note: OBJ_DEAD 365 * objects can be referenced during final cleaning. 366 */ 367 void 368 vm_object_reference(vm_object_t object) 369 { 370 if (object == NULL) 371 return; 372 VM_OBJECT_LOCK(object); 373 vm_object_reference_locked(object); 374 VM_OBJECT_UNLOCK(object); 375 } 376 377 /* 378 * vm_object_reference_locked: 379 * 380 * Gets another reference to the given object. 381 * 382 * The object must be locked. 383 */ 384 void 385 vm_object_reference_locked(vm_object_t object) 386 { 387 struct vnode *vp; 388 389 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 390 object->ref_count++; 391 if (object->type == OBJT_VNODE) { 392 vp = object->handle; 393 vref(vp); 394 } 395 } 396 397 /* 398 * Handle deallocating an object of type OBJT_VNODE. 399 */ 400 static void 401 vm_object_vndeallocate(vm_object_t object) 402 { 403 struct vnode *vp = (struct vnode *) object->handle; 404 405 VFS_ASSERT_GIANT(vp->v_mount); 406 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 407 KASSERT(object->type == OBJT_VNODE, 408 ("vm_object_vndeallocate: not a vnode object")); 409 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 410 #ifdef INVARIANTS 411 if (object->ref_count == 0) { 412 vprint("vm_object_vndeallocate", vp); 413 panic("vm_object_vndeallocate: bad object reference count"); 414 } 415 #endif 416 417 object->ref_count--; 418 if (object->ref_count == 0) { 419 mp_fixme("Unlocked vflag access."); 420 vp->v_vflag &= ~VV_TEXT; 421 } 422 VM_OBJECT_UNLOCK(object); 423 /* 424 * vrele may need a vop lock 425 */ 426 vrele(vp); 427 } 428 429 /* 430 * vm_object_deallocate: 431 * 432 * Release a reference to the specified object, 433 * gained either through a vm_object_allocate 434 * or a vm_object_reference call. When all references 435 * are gone, storage associated with this object 436 * may be relinquished. 437 * 438 * No object may be locked. 439 */ 440 void 441 vm_object_deallocate(vm_object_t object) 442 { 443 vm_object_t temp; 444 445 while (object != NULL) { 446 int vfslocked; 447 448 vfslocked = 0; 449 restart: 450 VM_OBJECT_LOCK(object); 451 if (object->type == OBJT_VNODE) { 452 struct vnode *vp = (struct vnode *) object->handle; 453 454 /* 455 * Conditionally acquire Giant for a vnode-backed 456 * object. We have to be careful since the type of 457 * a vnode object can change while the object is 458 * unlocked. 459 */ 460 if (VFS_NEEDSGIANT(vp->v_mount) && !vfslocked) { 461 vfslocked = 1; 462 if (!mtx_trylock(&Giant)) { 463 VM_OBJECT_UNLOCK(object); 464 mtx_lock(&Giant); 465 goto restart; 466 } 467 } 468 vm_object_vndeallocate(object); 469 VFS_UNLOCK_GIANT(vfslocked); 470 return; 471 } else 472 /* 473 * This is to handle the case that the object 474 * changed type while we dropped its lock to 475 * obtain Giant. 476 */ 477 VFS_UNLOCK_GIANT(vfslocked); 478 479 KASSERT(object->ref_count != 0, 480 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 481 482 /* 483 * If the reference count goes to 0 we start calling 484 * vm_object_terminate() on the object chain. 485 * A ref count of 1 may be a special case depending on the 486 * shadow count being 0 or 1. 487 */ 488 object->ref_count--; 489 if (object->ref_count > 1) { 490 VM_OBJECT_UNLOCK(object); 491 return; 492 } else if (object->ref_count == 1) { 493 if (object->shadow_count == 0 && 494 object->handle == NULL && 495 (object->type == OBJT_DEFAULT || 496 object->type == OBJT_SWAP)) { 497 vm_object_set_flag(object, OBJ_ONEMAPPING); 498 } else if ((object->shadow_count == 1) && 499 (object->handle == NULL) && 500 (object->type == OBJT_DEFAULT || 501 object->type == OBJT_SWAP)) { 502 vm_object_t robject; 503 504 robject = LIST_FIRST(&object->shadow_head); 505 KASSERT(robject != NULL, 506 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 507 object->ref_count, 508 object->shadow_count)); 509 if (!VM_OBJECT_TRYLOCK(robject)) { 510 /* 511 * Avoid a potential deadlock. 512 */ 513 object->ref_count++; 514 VM_OBJECT_UNLOCK(object); 515 /* 516 * More likely than not the thread 517 * holding robject's lock has lower 518 * priority than the current thread. 519 * Let the lower priority thread run. 520 */ 521 pause("vmo_de", 1); 522 continue; 523 } 524 /* 525 * Collapse object into its shadow unless its 526 * shadow is dead. In that case, object will 527 * be deallocated by the thread that is 528 * deallocating its shadow. 529 */ 530 if ((robject->flags & OBJ_DEAD) == 0 && 531 (robject->handle == NULL) && 532 (robject->type == OBJT_DEFAULT || 533 robject->type == OBJT_SWAP)) { 534 535 robject->ref_count++; 536 retry: 537 if (robject->paging_in_progress) { 538 VM_OBJECT_UNLOCK(object); 539 vm_object_pip_wait(robject, 540 "objde1"); 541 temp = robject->backing_object; 542 if (object == temp) { 543 VM_OBJECT_LOCK(object); 544 goto retry; 545 } 546 } else if (object->paging_in_progress) { 547 VM_OBJECT_UNLOCK(robject); 548 object->flags |= OBJ_PIPWNT; 549 msleep(object, 550 VM_OBJECT_MTX(object), 551 PDROP | PVM, "objde2", 0); 552 VM_OBJECT_LOCK(robject); 553 temp = robject->backing_object; 554 if (object == temp) { 555 VM_OBJECT_LOCK(object); 556 goto retry; 557 } 558 } else 559 VM_OBJECT_UNLOCK(object); 560 561 if (robject->ref_count == 1) { 562 robject->ref_count--; 563 object = robject; 564 goto doterm; 565 } 566 object = robject; 567 vm_object_collapse(object); 568 VM_OBJECT_UNLOCK(object); 569 continue; 570 } 571 VM_OBJECT_UNLOCK(robject); 572 } 573 VM_OBJECT_UNLOCK(object); 574 return; 575 } 576 doterm: 577 temp = object->backing_object; 578 if (temp != NULL) { 579 VM_OBJECT_LOCK(temp); 580 LIST_REMOVE(object, shadow_list); 581 temp->shadow_count--; 582 temp->generation++; 583 VM_OBJECT_UNLOCK(temp); 584 object->backing_object = NULL; 585 } 586 /* 587 * Don't double-terminate, we could be in a termination 588 * recursion due to the terminate having to sync data 589 * to disk. 590 */ 591 if ((object->flags & OBJ_DEAD) == 0) 592 vm_object_terminate(object); 593 else 594 VM_OBJECT_UNLOCK(object); 595 object = temp; 596 } 597 } 598 599 /* 600 * vm_object_destroy removes the object from the global object list 601 * and frees the space for the object. 602 */ 603 void 604 vm_object_destroy(vm_object_t object) 605 { 606 607 /* 608 * Remove the object from the global object list. 609 */ 610 mtx_lock(&vm_object_list_mtx); 611 TAILQ_REMOVE(&vm_object_list, object, object_list); 612 mtx_unlock(&vm_object_list_mtx); 613 614 /* 615 * Release the allocation charge. 616 */ 617 if (object->uip != NULL) { 618 KASSERT(object->type == OBJT_DEFAULT || 619 object->type == OBJT_SWAP, 620 ("vm_object_terminate: non-swap obj %p has uip", 621 object)); 622 swap_release_by_uid(object->charge, object->uip); 623 object->charge = 0; 624 uifree(object->uip); 625 object->uip = NULL; 626 } 627 628 /* 629 * Free the space for the object. 630 */ 631 uma_zfree(obj_zone, object); 632 } 633 634 /* 635 * vm_object_terminate actually destroys the specified object, freeing 636 * up all previously used resources. 637 * 638 * The object must be locked. 639 * This routine may block. 640 */ 641 void 642 vm_object_terminate(vm_object_t object) 643 { 644 vm_page_t p; 645 646 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 647 648 /* 649 * Make sure no one uses us. 650 */ 651 vm_object_set_flag(object, OBJ_DEAD); 652 653 /* 654 * wait for the pageout daemon to be done with the object 655 */ 656 vm_object_pip_wait(object, "objtrm"); 657 658 KASSERT(!object->paging_in_progress, 659 ("vm_object_terminate: pageout in progress")); 660 661 /* 662 * Clean and free the pages, as appropriate. All references to the 663 * object are gone, so we don't need to lock it. 664 */ 665 if (object->type == OBJT_VNODE) { 666 struct vnode *vp = (struct vnode *)object->handle; 667 668 /* 669 * Clean pages and flush buffers. 670 */ 671 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 672 VM_OBJECT_UNLOCK(object); 673 674 vinvalbuf(vp, V_SAVE, 0, 0); 675 676 VM_OBJECT_LOCK(object); 677 } 678 679 KASSERT(object->ref_count == 0, 680 ("vm_object_terminate: object with references, ref_count=%d", 681 object->ref_count)); 682 683 /* 684 * Now free any remaining pages. For internal objects, this also 685 * removes them from paging queues. Don't free wired pages, just 686 * remove them from the object. 687 */ 688 vm_page_lock_queues(); 689 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 690 KASSERT(!p->busy && (p->oflags & VPO_BUSY) == 0, 691 ("vm_object_terminate: freeing busy page %p " 692 "p->busy = %d, p->oflags %x\n", p, p->busy, p->oflags)); 693 if (p->wire_count == 0) { 694 vm_page_free(p); 695 cnt.v_pfree++; 696 } else { 697 vm_page_remove(p); 698 } 699 } 700 vm_page_unlock_queues(); 701 702 #if VM_NRESERVLEVEL > 0 703 if (__predict_false(!LIST_EMPTY(&object->rvq))) 704 vm_reserv_break_all(object); 705 #endif 706 if (__predict_false(object->cache != NULL)) 707 vm_page_cache_free(object, 0, 0); 708 709 /* 710 * Let the pager know object is dead. 711 */ 712 vm_pager_deallocate(object); 713 VM_OBJECT_UNLOCK(object); 714 715 vm_object_destroy(object); 716 } 717 718 /* 719 * vm_object_page_clean 720 * 721 * Clean all dirty pages in the specified range of object. Leaves page 722 * on whatever queue it is currently on. If NOSYNC is set then do not 723 * write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC), 724 * leaving the object dirty. 725 * 726 * When stuffing pages asynchronously, allow clustering. XXX we need a 727 * synchronous clustering mode implementation. 728 * 729 * Odd semantics: if start == end, we clean everything. 730 * 731 * The object must be locked. 732 */ 733 void 734 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 735 { 736 vm_page_t p, np; 737 vm_pindex_t tstart, tend; 738 vm_pindex_t pi; 739 int clearobjflags; 740 int pagerflags; 741 int curgeneration; 742 743 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 744 if (object->type != OBJT_VNODE || 745 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 746 return; 747 748 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 749 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 750 751 vm_object_set_flag(object, OBJ_CLEANING); 752 753 tstart = start; 754 if (end == 0) { 755 tend = object->size; 756 } else { 757 tend = end; 758 } 759 760 vm_page_lock_queues(); 761 /* 762 * If the caller is smart and only msync()s a range he knows is 763 * dirty, we may be able to avoid an object scan. This results in 764 * a phenominal improvement in performance. We cannot do this 765 * as a matter of course because the object may be huge - e.g. 766 * the size might be in the gigabytes or terrabytes. 767 */ 768 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 769 vm_pindex_t tscan; 770 int scanlimit; 771 int scanreset; 772 773 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 774 if (scanreset < 16) 775 scanreset = 16; 776 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 777 778 scanlimit = scanreset; 779 tscan = tstart; 780 while (tscan < tend) { 781 curgeneration = object->generation; 782 p = vm_page_lookup(object, tscan); 783 if (p == NULL || p->valid == 0) { 784 if (--scanlimit == 0) 785 break; 786 ++tscan; 787 continue; 788 } 789 vm_page_test_dirty(p); 790 if (p->dirty == 0) { 791 if (--scanlimit == 0) 792 break; 793 ++tscan; 794 continue; 795 } 796 /* 797 * If we have been asked to skip nosync pages and 798 * this is a nosync page, we can't continue. 799 */ 800 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 801 if (--scanlimit == 0) 802 break; 803 ++tscan; 804 continue; 805 } 806 scanlimit = scanreset; 807 808 /* 809 * This returns 0 if it was unable to busy the first 810 * page (i.e. had to sleep). 811 */ 812 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 813 } 814 815 /* 816 * If everything was dirty and we flushed it successfully, 817 * and the requested range is not the entire object, we 818 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 819 * return immediately. 820 */ 821 if (tscan >= tend && (tstart || tend < object->size)) { 822 vm_page_unlock_queues(); 823 vm_object_clear_flag(object, OBJ_CLEANING); 824 return; 825 } 826 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 827 } 828 829 /* 830 * Generally set CLEANCHK interlock and make the page read-only so 831 * we can then clear the object flags. 832 * 833 * However, if this is a nosync mmap then the object is likely to 834 * stay dirty so do not mess with the page and do not clear the 835 * object flags. 836 */ 837 clearobjflags = 1; 838 TAILQ_FOREACH(p, &object->memq, listq) { 839 p->oflags |= VPO_CLEANCHK; 840 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) 841 clearobjflags = 0; 842 else 843 pmap_remove_write(p); 844 } 845 846 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 847 struct vnode *vp; 848 849 vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY); 850 if (object->type == OBJT_VNODE && 851 (vp = (struct vnode *)object->handle) != NULL) { 852 VI_LOCK(vp); 853 if (vp->v_iflag & VI_OBJDIRTY) 854 vp->v_iflag &= ~VI_OBJDIRTY; 855 VI_UNLOCK(vp); 856 } 857 } 858 859 rescan: 860 curgeneration = object->generation; 861 862 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 863 int n; 864 865 np = TAILQ_NEXT(p, listq); 866 867 again: 868 pi = p->pindex; 869 if ((p->oflags & VPO_CLEANCHK) == 0 || 870 (pi < tstart) || (pi >= tend) || 871 p->valid == 0) { 872 p->oflags &= ~VPO_CLEANCHK; 873 continue; 874 } 875 876 vm_page_test_dirty(p); 877 if (p->dirty == 0) { 878 p->oflags &= ~VPO_CLEANCHK; 879 continue; 880 } 881 882 /* 883 * If we have been asked to skip nosync pages and this is a 884 * nosync page, skip it. Note that the object flags were 885 * not cleared in this case so we do not have to set them. 886 */ 887 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 888 p->oflags &= ~VPO_CLEANCHK; 889 continue; 890 } 891 892 n = vm_object_page_collect_flush(object, p, 893 curgeneration, pagerflags); 894 if (n == 0) 895 goto rescan; 896 897 if (object->generation != curgeneration) 898 goto rescan; 899 900 /* 901 * Try to optimize the next page. If we can't we pick up 902 * our (random) scan where we left off. 903 */ 904 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 905 if ((p = vm_page_lookup(object, pi + n)) != NULL) 906 goto again; 907 } 908 } 909 vm_page_unlock_queues(); 910 #if 0 911 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 912 #endif 913 914 vm_object_clear_flag(object, OBJ_CLEANING); 915 return; 916 } 917 918 static int 919 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 920 { 921 int runlen; 922 int maxf; 923 int chkb; 924 int maxb; 925 int i; 926 vm_pindex_t pi; 927 vm_page_t maf[vm_pageout_page_count]; 928 vm_page_t mab[vm_pageout_page_count]; 929 vm_page_t ma[vm_pageout_page_count]; 930 931 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 932 pi = p->pindex; 933 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 934 vm_page_lock_queues(); 935 if (object->generation != curgeneration) { 936 return(0); 937 } 938 } 939 maxf = 0; 940 for(i = 1; i < vm_pageout_page_count; i++) { 941 vm_page_t tp; 942 943 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 944 if ((tp->oflags & VPO_BUSY) || 945 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 946 (tp->oflags & VPO_CLEANCHK) == 0) || 947 (tp->busy != 0)) 948 break; 949 vm_page_test_dirty(tp); 950 if (tp->dirty == 0) { 951 tp->oflags &= ~VPO_CLEANCHK; 952 break; 953 } 954 maf[ i - 1 ] = tp; 955 maxf++; 956 continue; 957 } 958 break; 959 } 960 961 maxb = 0; 962 chkb = vm_pageout_page_count - maxf; 963 if (chkb) { 964 for(i = 1; i < chkb;i++) { 965 vm_page_t tp; 966 967 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 968 if ((tp->oflags & VPO_BUSY) || 969 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 970 (tp->oflags & VPO_CLEANCHK) == 0) || 971 (tp->busy != 0)) 972 break; 973 vm_page_test_dirty(tp); 974 if (tp->dirty == 0) { 975 tp->oflags &= ~VPO_CLEANCHK; 976 break; 977 } 978 mab[ i - 1 ] = tp; 979 maxb++; 980 continue; 981 } 982 break; 983 } 984 } 985 986 for(i = 0; i < maxb; i++) { 987 int index = (maxb - i) - 1; 988 ma[index] = mab[i]; 989 ma[index]->oflags &= ~VPO_CLEANCHK; 990 } 991 p->oflags &= ~VPO_CLEANCHK; 992 ma[maxb] = p; 993 for(i = 0; i < maxf; i++) { 994 int index = (maxb + i) + 1; 995 ma[index] = maf[i]; 996 ma[index]->oflags &= ~VPO_CLEANCHK; 997 } 998 runlen = maxb + maxf + 1; 999 1000 vm_pageout_flush(ma, runlen, pagerflags); 1001 for (i = 0; i < runlen; i++) { 1002 if (ma[i]->dirty) { 1003 pmap_remove_write(ma[i]); 1004 ma[i]->oflags |= VPO_CLEANCHK; 1005 1006 /* 1007 * maxf will end up being the actual number of pages 1008 * we wrote out contiguously, non-inclusive of the 1009 * first page. We do not count look-behind pages. 1010 */ 1011 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 1012 maxf = i - maxb - 1; 1013 } 1014 } 1015 return(maxf + 1); 1016 } 1017 1018 /* 1019 * Note that there is absolutely no sense in writing out 1020 * anonymous objects, so we track down the vnode object 1021 * to write out. 1022 * We invalidate (remove) all pages from the address space 1023 * for semantic correctness. 1024 * 1025 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1026 * may start out with a NULL object. 1027 */ 1028 void 1029 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1030 boolean_t syncio, boolean_t invalidate) 1031 { 1032 vm_object_t backing_object; 1033 struct vnode *vp; 1034 struct mount *mp; 1035 int flags; 1036 1037 if (object == NULL) 1038 return; 1039 VM_OBJECT_LOCK(object); 1040 while ((backing_object = object->backing_object) != NULL) { 1041 VM_OBJECT_LOCK(backing_object); 1042 offset += object->backing_object_offset; 1043 VM_OBJECT_UNLOCK(object); 1044 object = backing_object; 1045 if (object->size < OFF_TO_IDX(offset + size)) 1046 size = IDX_TO_OFF(object->size) - offset; 1047 } 1048 /* 1049 * Flush pages if writing is allowed, invalidate them 1050 * if invalidation requested. Pages undergoing I/O 1051 * will be ignored by vm_object_page_remove(). 1052 * 1053 * We cannot lock the vnode and then wait for paging 1054 * to complete without deadlocking against vm_fault. 1055 * Instead we simply call vm_object_page_remove() and 1056 * allow it to block internally on a page-by-page 1057 * basis when it encounters pages undergoing async 1058 * I/O. 1059 */ 1060 if (object->type == OBJT_VNODE && 1061 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1062 int vfslocked; 1063 vp = object->handle; 1064 VM_OBJECT_UNLOCK(object); 1065 (void) vn_start_write(vp, &mp, V_WAIT); 1066 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1067 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1068 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1069 flags |= invalidate ? OBJPC_INVAL : 0; 1070 VM_OBJECT_LOCK(object); 1071 vm_object_page_clean(object, 1072 OFF_TO_IDX(offset), 1073 OFF_TO_IDX(offset + size + PAGE_MASK), 1074 flags); 1075 VM_OBJECT_UNLOCK(object); 1076 VOP_UNLOCK(vp, 0); 1077 VFS_UNLOCK_GIANT(vfslocked); 1078 vn_finished_write(mp); 1079 VM_OBJECT_LOCK(object); 1080 } 1081 if ((object->type == OBJT_VNODE || 1082 object->type == OBJT_DEVICE) && invalidate) { 1083 boolean_t purge; 1084 purge = old_msync || (object->type == OBJT_DEVICE); 1085 vm_object_page_remove(object, 1086 OFF_TO_IDX(offset), 1087 OFF_TO_IDX(offset + size + PAGE_MASK), 1088 purge ? FALSE : TRUE); 1089 } 1090 VM_OBJECT_UNLOCK(object); 1091 } 1092 1093 /* 1094 * vm_object_madvise: 1095 * 1096 * Implements the madvise function at the object/page level. 1097 * 1098 * MADV_WILLNEED (any object) 1099 * 1100 * Activate the specified pages if they are resident. 1101 * 1102 * MADV_DONTNEED (any object) 1103 * 1104 * Deactivate the specified pages if they are resident. 1105 * 1106 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1107 * OBJ_ONEMAPPING only) 1108 * 1109 * Deactivate and clean the specified pages if they are 1110 * resident. This permits the process to reuse the pages 1111 * without faulting or the kernel to reclaim the pages 1112 * without I/O. 1113 */ 1114 void 1115 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1116 { 1117 vm_pindex_t end, tpindex; 1118 vm_object_t backing_object, tobject; 1119 vm_page_t m; 1120 1121 if (object == NULL) 1122 return; 1123 VM_OBJECT_LOCK(object); 1124 end = pindex + count; 1125 /* 1126 * Locate and adjust resident pages 1127 */ 1128 for (; pindex < end; pindex += 1) { 1129 relookup: 1130 tobject = object; 1131 tpindex = pindex; 1132 shadowlookup: 1133 /* 1134 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1135 * and those pages must be OBJ_ONEMAPPING. 1136 */ 1137 if (advise == MADV_FREE) { 1138 if ((tobject->type != OBJT_DEFAULT && 1139 tobject->type != OBJT_SWAP) || 1140 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1141 goto unlock_tobject; 1142 } 1143 } 1144 m = vm_page_lookup(tobject, tpindex); 1145 if (m == NULL && advise == MADV_WILLNEED) { 1146 /* 1147 * If the page is cached, reactivate it. 1148 */ 1149 m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED | 1150 VM_ALLOC_NOBUSY); 1151 } 1152 if (m == NULL) { 1153 /* 1154 * There may be swap even if there is no backing page 1155 */ 1156 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1157 swap_pager_freespace(tobject, tpindex, 1); 1158 /* 1159 * next object 1160 */ 1161 backing_object = tobject->backing_object; 1162 if (backing_object == NULL) 1163 goto unlock_tobject; 1164 VM_OBJECT_LOCK(backing_object); 1165 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1166 if (tobject != object) 1167 VM_OBJECT_UNLOCK(tobject); 1168 tobject = backing_object; 1169 goto shadowlookup; 1170 } 1171 /* 1172 * If the page is busy or not in a normal active state, 1173 * we skip it. If the page is not managed there are no 1174 * page queues to mess with. Things can break if we mess 1175 * with pages in any of the below states. 1176 */ 1177 vm_page_lock_queues(); 1178 if (m->hold_count || 1179 m->wire_count || 1180 (m->flags & PG_UNMANAGED) || 1181 m->valid != VM_PAGE_BITS_ALL) { 1182 vm_page_unlock_queues(); 1183 goto unlock_tobject; 1184 } 1185 if ((m->oflags & VPO_BUSY) || m->busy) { 1186 vm_page_flag_set(m, PG_REFERENCED); 1187 vm_page_unlock_queues(); 1188 if (object != tobject) 1189 VM_OBJECT_UNLOCK(object); 1190 m->oflags |= VPO_WANTED; 1191 msleep(m, VM_OBJECT_MTX(tobject), PDROP | PVM, "madvpo", 0); 1192 VM_OBJECT_LOCK(object); 1193 goto relookup; 1194 } 1195 if (advise == MADV_WILLNEED) { 1196 vm_page_activate(m); 1197 } else if (advise == MADV_DONTNEED) { 1198 vm_page_dontneed(m); 1199 } else if (advise == MADV_FREE) { 1200 /* 1201 * Mark the page clean. This will allow the page 1202 * to be freed up by the system. However, such pages 1203 * are often reused quickly by malloc()/free() 1204 * so we do not do anything that would cause 1205 * a page fault if we can help it. 1206 * 1207 * Specifically, we do not try to actually free 1208 * the page now nor do we try to put it in the 1209 * cache (which would cause a page fault on reuse). 1210 * 1211 * But we do make the page is freeable as we 1212 * can without actually taking the step of unmapping 1213 * it. 1214 */ 1215 pmap_clear_modify(m); 1216 m->dirty = 0; 1217 m->act_count = 0; 1218 vm_page_dontneed(m); 1219 } 1220 vm_page_unlock_queues(); 1221 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1222 swap_pager_freespace(tobject, tpindex, 1); 1223 unlock_tobject: 1224 if (tobject != object) 1225 VM_OBJECT_UNLOCK(tobject); 1226 } 1227 VM_OBJECT_UNLOCK(object); 1228 } 1229 1230 /* 1231 * vm_object_shadow: 1232 * 1233 * Create a new object which is backed by the 1234 * specified existing object range. The source 1235 * object reference is deallocated. 1236 * 1237 * The new object and offset into that object 1238 * are returned in the source parameters. 1239 */ 1240 void 1241 vm_object_shadow( 1242 vm_object_t *object, /* IN/OUT */ 1243 vm_ooffset_t *offset, /* IN/OUT */ 1244 vm_size_t length) 1245 { 1246 vm_object_t source; 1247 vm_object_t result; 1248 1249 source = *object; 1250 1251 /* 1252 * Don't create the new object if the old object isn't shared. 1253 */ 1254 if (source != NULL) { 1255 VM_OBJECT_LOCK(source); 1256 if (source->ref_count == 1 && 1257 source->handle == NULL && 1258 (source->type == OBJT_DEFAULT || 1259 source->type == OBJT_SWAP)) { 1260 VM_OBJECT_UNLOCK(source); 1261 return; 1262 } 1263 VM_OBJECT_UNLOCK(source); 1264 } 1265 1266 /* 1267 * Allocate a new object with the given length. 1268 */ 1269 result = vm_object_allocate(OBJT_DEFAULT, length); 1270 1271 /* 1272 * The new object shadows the source object, adding a reference to it. 1273 * Our caller changes his reference to point to the new object, 1274 * removing a reference to the source object. Net result: no change 1275 * of reference count. 1276 * 1277 * Try to optimize the result object's page color when shadowing 1278 * in order to maintain page coloring consistency in the combined 1279 * shadowed object. 1280 */ 1281 result->backing_object = source; 1282 /* 1283 * Store the offset into the source object, and fix up the offset into 1284 * the new object. 1285 */ 1286 result->backing_object_offset = *offset; 1287 if (source != NULL) { 1288 VM_OBJECT_LOCK(source); 1289 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1290 source->shadow_count++; 1291 source->generation++; 1292 #if VM_NRESERVLEVEL > 0 1293 result->flags |= source->flags & OBJ_COLORED; 1294 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & 1295 ((1 << (VM_NFREEORDER - 1)) - 1); 1296 #endif 1297 VM_OBJECT_UNLOCK(source); 1298 } 1299 1300 1301 /* 1302 * Return the new things 1303 */ 1304 *offset = 0; 1305 *object = result; 1306 } 1307 1308 /* 1309 * vm_object_split: 1310 * 1311 * Split the pages in a map entry into a new object. This affords 1312 * easier removal of unused pages, and keeps object inheritance from 1313 * being a negative impact on memory usage. 1314 */ 1315 void 1316 vm_object_split(vm_map_entry_t entry) 1317 { 1318 vm_page_t m, m_next; 1319 vm_object_t orig_object, new_object, source; 1320 vm_pindex_t idx, offidxstart; 1321 vm_size_t size; 1322 1323 orig_object = entry->object.vm_object; 1324 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1325 return; 1326 if (orig_object->ref_count <= 1) 1327 return; 1328 VM_OBJECT_UNLOCK(orig_object); 1329 1330 offidxstart = OFF_TO_IDX(entry->offset); 1331 size = atop(entry->end - entry->start); 1332 1333 /* 1334 * If swap_pager_copy() is later called, it will convert new_object 1335 * into a swap object. 1336 */ 1337 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1338 1339 /* 1340 * At this point, the new object is still private, so the order in 1341 * which the original and new objects are locked does not matter. 1342 */ 1343 VM_OBJECT_LOCK(new_object); 1344 VM_OBJECT_LOCK(orig_object); 1345 source = orig_object->backing_object; 1346 if (source != NULL) { 1347 VM_OBJECT_LOCK(source); 1348 if ((source->flags & OBJ_DEAD) != 0) { 1349 VM_OBJECT_UNLOCK(source); 1350 VM_OBJECT_UNLOCK(orig_object); 1351 VM_OBJECT_UNLOCK(new_object); 1352 vm_object_deallocate(new_object); 1353 VM_OBJECT_LOCK(orig_object); 1354 return; 1355 } 1356 LIST_INSERT_HEAD(&source->shadow_head, 1357 new_object, shadow_list); 1358 source->shadow_count++; 1359 source->generation++; 1360 vm_object_reference_locked(source); /* for new_object */ 1361 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1362 VM_OBJECT_UNLOCK(source); 1363 new_object->backing_object_offset = 1364 orig_object->backing_object_offset + entry->offset; 1365 new_object->backing_object = source; 1366 } 1367 if (orig_object->uip != NULL) { 1368 new_object->uip = orig_object->uip; 1369 uihold(orig_object->uip); 1370 new_object->charge = ptoa(size); 1371 KASSERT(orig_object->charge >= ptoa(size), 1372 ("orig_object->charge < 0")); 1373 orig_object->charge -= ptoa(size); 1374 } 1375 retry: 1376 if ((m = TAILQ_FIRST(&orig_object->memq)) != NULL) { 1377 if (m->pindex < offidxstart) { 1378 m = vm_page_splay(offidxstart, orig_object->root); 1379 if ((orig_object->root = m)->pindex < offidxstart) 1380 m = TAILQ_NEXT(m, listq); 1381 } 1382 } 1383 vm_page_lock_queues(); 1384 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1385 m = m_next) { 1386 m_next = TAILQ_NEXT(m, listq); 1387 1388 /* 1389 * We must wait for pending I/O to complete before we can 1390 * rename the page. 1391 * 1392 * We do not have to VM_PROT_NONE the page as mappings should 1393 * not be changed by this operation. 1394 */ 1395 if ((m->oflags & VPO_BUSY) || m->busy) { 1396 vm_page_flag_set(m, PG_REFERENCED); 1397 vm_page_unlock_queues(); 1398 VM_OBJECT_UNLOCK(new_object); 1399 m->oflags |= VPO_WANTED; 1400 msleep(m, VM_OBJECT_MTX(orig_object), PVM, "spltwt", 0); 1401 VM_OBJECT_LOCK(new_object); 1402 goto retry; 1403 } 1404 vm_page_rename(m, new_object, idx); 1405 /* page automatically made dirty by rename and cache handled */ 1406 vm_page_busy(m); 1407 } 1408 vm_page_unlock_queues(); 1409 if (orig_object->type == OBJT_SWAP) { 1410 /* 1411 * swap_pager_copy() can sleep, in which case the orig_object's 1412 * and new_object's locks are released and reacquired. 1413 */ 1414 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1415 1416 /* 1417 * Transfer any cached pages from orig_object to new_object. 1418 */ 1419 if (__predict_false(orig_object->cache != NULL)) 1420 vm_page_cache_transfer(orig_object, offidxstart, 1421 new_object); 1422 } 1423 VM_OBJECT_UNLOCK(orig_object); 1424 TAILQ_FOREACH(m, &new_object->memq, listq) 1425 vm_page_wakeup(m); 1426 VM_OBJECT_UNLOCK(new_object); 1427 entry->object.vm_object = new_object; 1428 entry->offset = 0LL; 1429 vm_object_deallocate(orig_object); 1430 VM_OBJECT_LOCK(new_object); 1431 } 1432 1433 #define OBSC_TEST_ALL_SHADOWED 0x0001 1434 #define OBSC_COLLAPSE_NOWAIT 0x0002 1435 #define OBSC_COLLAPSE_WAIT 0x0004 1436 1437 static int 1438 vm_object_backing_scan(vm_object_t object, int op) 1439 { 1440 int r = 1; 1441 vm_page_t p; 1442 vm_object_t backing_object; 1443 vm_pindex_t backing_offset_index; 1444 1445 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1446 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1447 1448 backing_object = object->backing_object; 1449 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1450 1451 /* 1452 * Initial conditions 1453 */ 1454 if (op & OBSC_TEST_ALL_SHADOWED) { 1455 /* 1456 * We do not want to have to test for the existence of cache 1457 * or swap pages in the backing object. XXX but with the 1458 * new swapper this would be pretty easy to do. 1459 * 1460 * XXX what about anonymous MAP_SHARED memory that hasn't 1461 * been ZFOD faulted yet? If we do not test for this, the 1462 * shadow test may succeed! XXX 1463 */ 1464 if (backing_object->type != OBJT_DEFAULT) { 1465 return (0); 1466 } 1467 } 1468 if (op & OBSC_COLLAPSE_WAIT) { 1469 vm_object_set_flag(backing_object, OBJ_DEAD); 1470 } 1471 1472 /* 1473 * Our scan 1474 */ 1475 p = TAILQ_FIRST(&backing_object->memq); 1476 while (p) { 1477 vm_page_t next = TAILQ_NEXT(p, listq); 1478 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1479 1480 if (op & OBSC_TEST_ALL_SHADOWED) { 1481 vm_page_t pp; 1482 1483 /* 1484 * Ignore pages outside the parent object's range 1485 * and outside the parent object's mapping of the 1486 * backing object. 1487 * 1488 * note that we do not busy the backing object's 1489 * page. 1490 */ 1491 if ( 1492 p->pindex < backing_offset_index || 1493 new_pindex >= object->size 1494 ) { 1495 p = next; 1496 continue; 1497 } 1498 1499 /* 1500 * See if the parent has the page or if the parent's 1501 * object pager has the page. If the parent has the 1502 * page but the page is not valid, the parent's 1503 * object pager must have the page. 1504 * 1505 * If this fails, the parent does not completely shadow 1506 * the object and we might as well give up now. 1507 */ 1508 1509 pp = vm_page_lookup(object, new_pindex); 1510 if ( 1511 (pp == NULL || pp->valid == 0) && 1512 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1513 ) { 1514 r = 0; 1515 break; 1516 } 1517 } 1518 1519 /* 1520 * Check for busy page 1521 */ 1522 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1523 vm_page_t pp; 1524 1525 if (op & OBSC_COLLAPSE_NOWAIT) { 1526 if ((p->oflags & VPO_BUSY) || 1527 !p->valid || 1528 p->busy) { 1529 p = next; 1530 continue; 1531 } 1532 } else if (op & OBSC_COLLAPSE_WAIT) { 1533 if ((p->oflags & VPO_BUSY) || p->busy) { 1534 vm_page_lock_queues(); 1535 vm_page_flag_set(p, PG_REFERENCED); 1536 vm_page_unlock_queues(); 1537 VM_OBJECT_UNLOCK(object); 1538 p->oflags |= VPO_WANTED; 1539 msleep(p, VM_OBJECT_MTX(backing_object), 1540 PDROP | PVM, "vmocol", 0); 1541 VM_OBJECT_LOCK(object); 1542 VM_OBJECT_LOCK(backing_object); 1543 /* 1544 * If we slept, anything could have 1545 * happened. Since the object is 1546 * marked dead, the backing offset 1547 * should not have changed so we 1548 * just restart our scan. 1549 */ 1550 p = TAILQ_FIRST(&backing_object->memq); 1551 continue; 1552 } 1553 } 1554 1555 KASSERT( 1556 p->object == backing_object, 1557 ("vm_object_backing_scan: object mismatch") 1558 ); 1559 1560 /* 1561 * Destroy any associated swap 1562 */ 1563 if (backing_object->type == OBJT_SWAP) { 1564 swap_pager_freespace( 1565 backing_object, 1566 p->pindex, 1567 1 1568 ); 1569 } 1570 1571 if ( 1572 p->pindex < backing_offset_index || 1573 new_pindex >= object->size 1574 ) { 1575 /* 1576 * Page is out of the parent object's range, we 1577 * can simply destroy it. 1578 */ 1579 vm_page_lock_queues(); 1580 KASSERT(!pmap_page_is_mapped(p), 1581 ("freeing mapped page %p", p)); 1582 if (p->wire_count == 0) 1583 vm_page_free(p); 1584 else 1585 vm_page_remove(p); 1586 vm_page_unlock_queues(); 1587 p = next; 1588 continue; 1589 } 1590 1591 pp = vm_page_lookup(object, new_pindex); 1592 if ( 1593 pp != NULL || 1594 vm_pager_has_page(object, new_pindex, NULL, NULL) 1595 ) { 1596 /* 1597 * page already exists in parent OR swap exists 1598 * for this location in the parent. Destroy 1599 * the original page from the backing object. 1600 * 1601 * Leave the parent's page alone 1602 */ 1603 vm_page_lock_queues(); 1604 KASSERT(!pmap_page_is_mapped(p), 1605 ("freeing mapped page %p", p)); 1606 if (p->wire_count == 0) 1607 vm_page_free(p); 1608 else 1609 vm_page_remove(p); 1610 vm_page_unlock_queues(); 1611 p = next; 1612 continue; 1613 } 1614 1615 #if VM_NRESERVLEVEL > 0 1616 /* 1617 * Rename the reservation. 1618 */ 1619 vm_reserv_rename(p, object, backing_object, 1620 backing_offset_index); 1621 #endif 1622 1623 /* 1624 * Page does not exist in parent, rename the 1625 * page from the backing object to the main object. 1626 * 1627 * If the page was mapped to a process, it can remain 1628 * mapped through the rename. 1629 */ 1630 vm_page_lock_queues(); 1631 vm_page_rename(p, object, new_pindex); 1632 vm_page_unlock_queues(); 1633 /* page automatically made dirty by rename */ 1634 } 1635 p = next; 1636 } 1637 return (r); 1638 } 1639 1640 1641 /* 1642 * this version of collapse allows the operation to occur earlier and 1643 * when paging_in_progress is true for an object... This is not a complete 1644 * operation, but should plug 99.9% of the rest of the leaks. 1645 */ 1646 static void 1647 vm_object_qcollapse(vm_object_t object) 1648 { 1649 vm_object_t backing_object = object->backing_object; 1650 1651 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1652 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1653 1654 if (backing_object->ref_count != 1) 1655 return; 1656 1657 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1658 } 1659 1660 /* 1661 * vm_object_collapse: 1662 * 1663 * Collapse an object with the object backing it. 1664 * Pages in the backing object are moved into the 1665 * parent, and the backing object is deallocated. 1666 */ 1667 void 1668 vm_object_collapse(vm_object_t object) 1669 { 1670 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1671 1672 while (TRUE) { 1673 vm_object_t backing_object; 1674 1675 /* 1676 * Verify that the conditions are right for collapse: 1677 * 1678 * The object exists and the backing object exists. 1679 */ 1680 if ((backing_object = object->backing_object) == NULL) 1681 break; 1682 1683 /* 1684 * we check the backing object first, because it is most likely 1685 * not collapsable. 1686 */ 1687 VM_OBJECT_LOCK(backing_object); 1688 if (backing_object->handle != NULL || 1689 (backing_object->type != OBJT_DEFAULT && 1690 backing_object->type != OBJT_SWAP) || 1691 (backing_object->flags & OBJ_DEAD) || 1692 object->handle != NULL || 1693 (object->type != OBJT_DEFAULT && 1694 object->type != OBJT_SWAP) || 1695 (object->flags & OBJ_DEAD)) { 1696 VM_OBJECT_UNLOCK(backing_object); 1697 break; 1698 } 1699 1700 if ( 1701 object->paging_in_progress != 0 || 1702 backing_object->paging_in_progress != 0 1703 ) { 1704 vm_object_qcollapse(object); 1705 VM_OBJECT_UNLOCK(backing_object); 1706 break; 1707 } 1708 /* 1709 * We know that we can either collapse the backing object (if 1710 * the parent is the only reference to it) or (perhaps) have 1711 * the parent bypass the object if the parent happens to shadow 1712 * all the resident pages in the entire backing object. 1713 * 1714 * This is ignoring pager-backed pages such as swap pages. 1715 * vm_object_backing_scan fails the shadowing test in this 1716 * case. 1717 */ 1718 if (backing_object->ref_count == 1) { 1719 /* 1720 * If there is exactly one reference to the backing 1721 * object, we can collapse it into the parent. 1722 */ 1723 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1724 1725 #if VM_NRESERVLEVEL > 0 1726 /* 1727 * Break any reservations from backing_object. 1728 */ 1729 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1730 vm_reserv_break_all(backing_object); 1731 #endif 1732 1733 /* 1734 * Move the pager from backing_object to object. 1735 */ 1736 if (backing_object->type == OBJT_SWAP) { 1737 /* 1738 * swap_pager_copy() can sleep, in which case 1739 * the backing_object's and object's locks are 1740 * released and reacquired. 1741 */ 1742 swap_pager_copy( 1743 backing_object, 1744 object, 1745 OFF_TO_IDX(object->backing_object_offset), TRUE); 1746 1747 /* 1748 * Free any cached pages from backing_object. 1749 */ 1750 if (__predict_false(backing_object->cache != NULL)) 1751 vm_page_cache_free(backing_object, 0, 0); 1752 } 1753 /* 1754 * Object now shadows whatever backing_object did. 1755 * Note that the reference to 1756 * backing_object->backing_object moves from within 1757 * backing_object to within object. 1758 */ 1759 LIST_REMOVE(object, shadow_list); 1760 backing_object->shadow_count--; 1761 backing_object->generation++; 1762 if (backing_object->backing_object) { 1763 VM_OBJECT_LOCK(backing_object->backing_object); 1764 LIST_REMOVE(backing_object, shadow_list); 1765 LIST_INSERT_HEAD( 1766 &backing_object->backing_object->shadow_head, 1767 object, shadow_list); 1768 /* 1769 * The shadow_count has not changed. 1770 */ 1771 backing_object->backing_object->generation++; 1772 VM_OBJECT_UNLOCK(backing_object->backing_object); 1773 } 1774 object->backing_object = backing_object->backing_object; 1775 object->backing_object_offset += 1776 backing_object->backing_object_offset; 1777 1778 /* 1779 * Discard backing_object. 1780 * 1781 * Since the backing object has no pages, no pager left, 1782 * and no object references within it, all that is 1783 * necessary is to dispose of it. 1784 */ 1785 KASSERT(backing_object->ref_count == 1, ( 1786 "backing_object %p was somehow re-referenced during collapse!", 1787 backing_object)); 1788 VM_OBJECT_UNLOCK(backing_object); 1789 vm_object_destroy(backing_object); 1790 1791 object_collapses++; 1792 } else { 1793 vm_object_t new_backing_object; 1794 1795 /* 1796 * If we do not entirely shadow the backing object, 1797 * there is nothing we can do so we give up. 1798 */ 1799 if (object->resident_page_count != object->size && 1800 vm_object_backing_scan(object, 1801 OBSC_TEST_ALL_SHADOWED) == 0) { 1802 VM_OBJECT_UNLOCK(backing_object); 1803 break; 1804 } 1805 1806 /* 1807 * Make the parent shadow the next object in the 1808 * chain. Deallocating backing_object will not remove 1809 * it, since its reference count is at least 2. 1810 */ 1811 LIST_REMOVE(object, shadow_list); 1812 backing_object->shadow_count--; 1813 backing_object->generation++; 1814 1815 new_backing_object = backing_object->backing_object; 1816 if ((object->backing_object = new_backing_object) != NULL) { 1817 VM_OBJECT_LOCK(new_backing_object); 1818 LIST_INSERT_HEAD( 1819 &new_backing_object->shadow_head, 1820 object, 1821 shadow_list 1822 ); 1823 new_backing_object->shadow_count++; 1824 new_backing_object->generation++; 1825 vm_object_reference_locked(new_backing_object); 1826 VM_OBJECT_UNLOCK(new_backing_object); 1827 object->backing_object_offset += 1828 backing_object->backing_object_offset; 1829 } 1830 1831 /* 1832 * Drop the reference count on backing_object. Since 1833 * its ref_count was at least 2, it will not vanish. 1834 */ 1835 backing_object->ref_count--; 1836 VM_OBJECT_UNLOCK(backing_object); 1837 object_bypasses++; 1838 } 1839 1840 /* 1841 * Try again with this object's new backing object. 1842 */ 1843 } 1844 } 1845 1846 /* 1847 * vm_object_page_remove: 1848 * 1849 * For the given object, either frees or invalidates each of the 1850 * specified pages. In general, a page is freed. However, if a 1851 * page is wired for any reason other than the existence of a 1852 * managed, wired mapping, then it may be invalidated but not 1853 * removed from the object. Pages are specified by the given 1854 * range ["start", "end") and Boolean "clean_only". As a 1855 * special case, if "end" is zero, then the range extends from 1856 * "start" to the end of the object. If "clean_only" is TRUE, 1857 * then only the non-dirty pages within the specified range are 1858 * affected. 1859 * 1860 * In general, this operation should only be performed on objects 1861 * that contain managed pages. There are two exceptions. First, 1862 * it may be performed on the kernel and kmem objects. Second, 1863 * it may be used by msync(..., MS_INVALIDATE) to invalidate 1864 * device-backed pages. 1865 * 1866 * The object must be locked. 1867 */ 1868 void 1869 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1870 boolean_t clean_only) 1871 { 1872 vm_page_t p, next; 1873 int wirings; 1874 1875 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1876 if (object->resident_page_count == 0) 1877 goto skipmemq; 1878 1879 /* 1880 * Since physically-backed objects do not use managed pages, we can't 1881 * remove pages from the object (we must instead remove the page 1882 * references, and then destroy the object). 1883 */ 1884 KASSERT(object->type != OBJT_PHYS || object == kernel_object || 1885 object == kmem_object, 1886 ("attempt to remove pages from a physical object")); 1887 1888 vm_object_pip_add(object, 1); 1889 again: 1890 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1891 if (p->pindex < start) { 1892 p = vm_page_splay(start, object->root); 1893 if ((object->root = p)->pindex < start) 1894 p = TAILQ_NEXT(p, listq); 1895 } 1896 } 1897 vm_page_lock_queues(); 1898 /* 1899 * Assert: the variable p is either (1) the page with the 1900 * least pindex greater than or equal to the parameter pindex 1901 * or (2) NULL. 1902 */ 1903 for (; 1904 p != NULL && (p->pindex < end || end == 0); 1905 p = next) { 1906 next = TAILQ_NEXT(p, listq); 1907 1908 /* 1909 * If the page is wired for any reason besides the 1910 * existence of managed, wired mappings, then it cannot 1911 * be freed. For example, fictitious pages, which 1912 * represent device memory, are inherently wired and 1913 * cannot be freed. They can, however, be invalidated 1914 * if "clean_only" is FALSE. 1915 */ 1916 if ((wirings = p->wire_count) != 0 && 1917 (wirings = pmap_page_wired_mappings(p)) != p->wire_count) { 1918 /* Fictitious pages do not have managed mappings. */ 1919 if ((p->flags & PG_FICTITIOUS) == 0) 1920 pmap_remove_all(p); 1921 /* Account for removal of managed, wired mappings. */ 1922 p->wire_count -= wirings; 1923 if (!clean_only) { 1924 p->valid = 0; 1925 vm_page_undirty(p); 1926 } 1927 continue; 1928 } 1929 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1930 goto again; 1931 KASSERT((p->flags & PG_FICTITIOUS) == 0, 1932 ("vm_object_page_remove: page %p is fictitious", p)); 1933 if (clean_only && p->valid) { 1934 pmap_remove_write(p); 1935 if (p->dirty) 1936 continue; 1937 } 1938 pmap_remove_all(p); 1939 /* Account for removal of managed, wired mappings. */ 1940 if (wirings != 0) 1941 p->wire_count -= wirings; 1942 vm_page_free(p); 1943 } 1944 vm_page_unlock_queues(); 1945 vm_object_pip_wakeup(object); 1946 skipmemq: 1947 if (__predict_false(object->cache != NULL)) 1948 vm_page_cache_free(object, start, end); 1949 } 1950 1951 /* 1952 * Populate the specified range of the object with valid pages. Returns 1953 * TRUE if the range is successfully populated and FALSE otherwise. 1954 * 1955 * Note: This function should be optimized to pass a larger array of 1956 * pages to vm_pager_get_pages() before it is applied to a non- 1957 * OBJT_DEVICE object. 1958 * 1959 * The object must be locked. 1960 */ 1961 boolean_t 1962 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1963 { 1964 vm_page_t m, ma[1]; 1965 vm_pindex_t pindex; 1966 int rv; 1967 1968 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1969 for (pindex = start; pindex < end; pindex++) { 1970 m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL | 1971 VM_ALLOC_RETRY); 1972 if (m->valid != VM_PAGE_BITS_ALL) { 1973 ma[0] = m; 1974 rv = vm_pager_get_pages(object, ma, 1, 0); 1975 m = vm_page_lookup(object, pindex); 1976 if (m == NULL) 1977 break; 1978 if (rv != VM_PAGER_OK) { 1979 vm_page_lock_queues(); 1980 vm_page_free(m); 1981 vm_page_unlock_queues(); 1982 break; 1983 } 1984 } 1985 /* 1986 * Keep "m" busy because a subsequent iteration may unlock 1987 * the object. 1988 */ 1989 } 1990 if (pindex > start) { 1991 m = vm_page_lookup(object, start); 1992 while (m != NULL && m->pindex < pindex) { 1993 vm_page_wakeup(m); 1994 m = TAILQ_NEXT(m, listq); 1995 } 1996 } 1997 return (pindex == end); 1998 } 1999 2000 /* 2001 * Routine: vm_object_coalesce 2002 * Function: Coalesces two objects backing up adjoining 2003 * regions of memory into a single object. 2004 * 2005 * returns TRUE if objects were combined. 2006 * 2007 * NOTE: Only works at the moment if the second object is NULL - 2008 * if it's not, which object do we lock first? 2009 * 2010 * Parameters: 2011 * prev_object First object to coalesce 2012 * prev_offset Offset into prev_object 2013 * prev_size Size of reference to prev_object 2014 * next_size Size of reference to the second object 2015 * reserved Indicator that extension region has 2016 * swap accounted for 2017 * 2018 * Conditions: 2019 * The object must *not* be locked. 2020 */ 2021 boolean_t 2022 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2023 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2024 { 2025 vm_pindex_t next_pindex; 2026 2027 if (prev_object == NULL) 2028 return (TRUE); 2029 VM_OBJECT_LOCK(prev_object); 2030 if (prev_object->type != OBJT_DEFAULT && 2031 prev_object->type != OBJT_SWAP) { 2032 VM_OBJECT_UNLOCK(prev_object); 2033 return (FALSE); 2034 } 2035 2036 /* 2037 * Try to collapse the object first 2038 */ 2039 vm_object_collapse(prev_object); 2040 2041 /* 2042 * Can't coalesce if: . more than one reference . paged out . shadows 2043 * another object . has a copy elsewhere (any of which mean that the 2044 * pages not mapped to prev_entry may be in use anyway) 2045 */ 2046 if (prev_object->backing_object != NULL) { 2047 VM_OBJECT_UNLOCK(prev_object); 2048 return (FALSE); 2049 } 2050 2051 prev_size >>= PAGE_SHIFT; 2052 next_size >>= PAGE_SHIFT; 2053 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2054 2055 if ((prev_object->ref_count > 1) && 2056 (prev_object->size != next_pindex)) { 2057 VM_OBJECT_UNLOCK(prev_object); 2058 return (FALSE); 2059 } 2060 2061 /* 2062 * Account for the charge. 2063 */ 2064 if (prev_object->uip != NULL) { 2065 2066 /* 2067 * If prev_object was charged, then this mapping, 2068 * althought not charged now, may become writable 2069 * later. Non-NULL uip in the object would prevent 2070 * swap reservation during enabling of the write 2071 * access, so reserve swap now. Failed reservation 2072 * cause allocation of the separate object for the map 2073 * entry, and swap reservation for this entry is 2074 * managed in appropriate time. 2075 */ 2076 if (!reserved && !swap_reserve_by_uid(ptoa(next_size), 2077 prev_object->uip)) { 2078 return (FALSE); 2079 } 2080 prev_object->charge += ptoa(next_size); 2081 } 2082 2083 /* 2084 * Remove any pages that may still be in the object from a previous 2085 * deallocation. 2086 */ 2087 if (next_pindex < prev_object->size) { 2088 vm_object_page_remove(prev_object, 2089 next_pindex, 2090 next_pindex + next_size, FALSE); 2091 if (prev_object->type == OBJT_SWAP) 2092 swap_pager_freespace(prev_object, 2093 next_pindex, next_size); 2094 #if 0 2095 if (prev_object->uip != NULL) { 2096 KASSERT(prev_object->charge >= 2097 ptoa(prev_object->size - next_pindex), 2098 ("object %p overcharged 1 %jx %jx", prev_object, 2099 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2100 prev_object->charge -= ptoa(prev_object->size - 2101 next_pindex); 2102 } 2103 #endif 2104 } 2105 2106 /* 2107 * Extend the object if necessary. 2108 */ 2109 if (next_pindex + next_size > prev_object->size) 2110 prev_object->size = next_pindex + next_size; 2111 2112 VM_OBJECT_UNLOCK(prev_object); 2113 return (TRUE); 2114 } 2115 2116 void 2117 vm_object_set_writeable_dirty(vm_object_t object) 2118 { 2119 struct vnode *vp; 2120 2121 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2122 if ((object->flags & OBJ_MIGHTBEDIRTY) != 0) 2123 return; 2124 vm_object_set_flag(object, OBJ_MIGHTBEDIRTY); 2125 if (object->type == OBJT_VNODE && 2126 (vp = (struct vnode *)object->handle) != NULL) { 2127 VI_LOCK(vp); 2128 vp->v_iflag |= VI_OBJDIRTY; 2129 VI_UNLOCK(vp); 2130 } 2131 } 2132 2133 #include "opt_ddb.h" 2134 #ifdef DDB 2135 #include <sys/kernel.h> 2136 2137 #include <sys/cons.h> 2138 2139 #include <ddb/ddb.h> 2140 2141 static int 2142 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2143 { 2144 vm_map_t tmpm; 2145 vm_map_entry_t tmpe; 2146 vm_object_t obj; 2147 int entcount; 2148 2149 if (map == 0) 2150 return 0; 2151 2152 if (entry == 0) { 2153 tmpe = map->header.next; 2154 entcount = map->nentries; 2155 while (entcount-- && (tmpe != &map->header)) { 2156 if (_vm_object_in_map(map, object, tmpe)) { 2157 return 1; 2158 } 2159 tmpe = tmpe->next; 2160 } 2161 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2162 tmpm = entry->object.sub_map; 2163 tmpe = tmpm->header.next; 2164 entcount = tmpm->nentries; 2165 while (entcount-- && tmpe != &tmpm->header) { 2166 if (_vm_object_in_map(tmpm, object, tmpe)) { 2167 return 1; 2168 } 2169 tmpe = tmpe->next; 2170 } 2171 } else if ((obj = entry->object.vm_object) != NULL) { 2172 for (; obj; obj = obj->backing_object) 2173 if (obj == object) { 2174 return 1; 2175 } 2176 } 2177 return 0; 2178 } 2179 2180 static int 2181 vm_object_in_map(vm_object_t object) 2182 { 2183 struct proc *p; 2184 2185 /* sx_slock(&allproc_lock); */ 2186 FOREACH_PROC_IN_SYSTEM(p) { 2187 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2188 continue; 2189 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2190 /* sx_sunlock(&allproc_lock); */ 2191 return 1; 2192 } 2193 } 2194 /* sx_sunlock(&allproc_lock); */ 2195 if (_vm_object_in_map(kernel_map, object, 0)) 2196 return 1; 2197 if (_vm_object_in_map(kmem_map, object, 0)) 2198 return 1; 2199 if (_vm_object_in_map(pager_map, object, 0)) 2200 return 1; 2201 if (_vm_object_in_map(buffer_map, object, 0)) 2202 return 1; 2203 return 0; 2204 } 2205 2206 DB_SHOW_COMMAND(vmochk, vm_object_check) 2207 { 2208 vm_object_t object; 2209 2210 /* 2211 * make sure that internal objs are in a map somewhere 2212 * and none have zero ref counts. 2213 */ 2214 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2215 if (object->handle == NULL && 2216 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2217 if (object->ref_count == 0) { 2218 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2219 (long)object->size); 2220 } 2221 if (!vm_object_in_map(object)) { 2222 db_printf( 2223 "vmochk: internal obj is not in a map: " 2224 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2225 object->ref_count, (u_long)object->size, 2226 (u_long)object->size, 2227 (void *)object->backing_object); 2228 } 2229 } 2230 } 2231 } 2232 2233 /* 2234 * vm_object_print: [ debug ] 2235 */ 2236 DB_SHOW_COMMAND(object, vm_object_print_static) 2237 { 2238 /* XXX convert args. */ 2239 vm_object_t object = (vm_object_t)addr; 2240 boolean_t full = have_addr; 2241 2242 vm_page_t p; 2243 2244 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2245 #define count was_count 2246 2247 int count; 2248 2249 if (object == NULL) 2250 return; 2251 2252 db_iprintf( 2253 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x uip %d charge %jx\n", 2254 object, (int)object->type, (uintmax_t)object->size, 2255 object->resident_page_count, object->ref_count, object->flags, 2256 object->uip ? object->uip->ui_uid : -1, (uintmax_t)object->charge); 2257 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2258 object->shadow_count, 2259 object->backing_object ? object->backing_object->ref_count : 0, 2260 object->backing_object, (uintmax_t)object->backing_object_offset); 2261 2262 if (!full) 2263 return; 2264 2265 db_indent += 2; 2266 count = 0; 2267 TAILQ_FOREACH(p, &object->memq, listq) { 2268 if (count == 0) 2269 db_iprintf("memory:="); 2270 else if (count == 6) { 2271 db_printf("\n"); 2272 db_iprintf(" ..."); 2273 count = 0; 2274 } else 2275 db_printf(","); 2276 count++; 2277 2278 db_printf("(off=0x%jx,page=0x%jx)", 2279 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2280 } 2281 if (count != 0) 2282 db_printf("\n"); 2283 db_indent -= 2; 2284 } 2285 2286 /* XXX. */ 2287 #undef count 2288 2289 /* XXX need this non-static entry for calling from vm_map_print. */ 2290 void 2291 vm_object_print( 2292 /* db_expr_t */ long addr, 2293 boolean_t have_addr, 2294 /* db_expr_t */ long count, 2295 char *modif) 2296 { 2297 vm_object_print_static(addr, have_addr, count, modif); 2298 } 2299 2300 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2301 { 2302 vm_object_t object; 2303 vm_pindex_t fidx; 2304 vm_paddr_t pa; 2305 vm_page_t m, prev_m; 2306 int rcount, nl, c; 2307 2308 nl = 0; 2309 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2310 db_printf("new object: %p\n", (void *)object); 2311 if (nl > 18) { 2312 c = cngetc(); 2313 if (c != ' ') 2314 return; 2315 nl = 0; 2316 } 2317 nl++; 2318 rcount = 0; 2319 fidx = 0; 2320 pa = -1; 2321 TAILQ_FOREACH(m, &object->memq, listq) { 2322 if (m->pindex > 128) 2323 break; 2324 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2325 prev_m->pindex + 1 != m->pindex) { 2326 if (rcount) { 2327 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2328 (long)fidx, rcount, (long)pa); 2329 if (nl > 18) { 2330 c = cngetc(); 2331 if (c != ' ') 2332 return; 2333 nl = 0; 2334 } 2335 nl++; 2336 rcount = 0; 2337 } 2338 } 2339 if (rcount && 2340 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2341 ++rcount; 2342 continue; 2343 } 2344 if (rcount) { 2345 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2346 (long)fidx, rcount, (long)pa); 2347 if (nl > 18) { 2348 c = cngetc(); 2349 if (c != ' ') 2350 return; 2351 nl = 0; 2352 } 2353 nl++; 2354 } 2355 fidx = m->pindex; 2356 pa = VM_PAGE_TO_PHYS(m); 2357 rcount = 1; 2358 } 2359 if (rcount) { 2360 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2361 (long)fidx, rcount, (long)pa); 2362 if (nl > 18) { 2363 c = cngetc(); 2364 if (c != ' ') 2365 return; 2366 nl = 0; 2367 } 2368 nl++; 2369 } 2370 } 2371 } 2372 #endif /* DDB */ 2373