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