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 } 617 618 619 620 /* 621 * vm_object_terminate actually destroys the specified object, freeing 622 * up all previously used resources. 623 * 624 * The object must be locked. 625 * This routine may block. 626 */ 627 void 628 vm_object_terminate(vm_object_t object) 629 { 630 vm_page_t p; 631 632 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 633 634 /* 635 * Make sure no one uses us. 636 */ 637 vm_object_set_flag(object, OBJ_DEAD); 638 639 /* 640 * wait for the pageout daemon to be done with the object 641 */ 642 vm_object_pip_wait(object, "objtrm"); 643 644 KASSERT(!object->paging_in_progress, 645 ("vm_object_terminate: pageout in progress")); 646 647 /* 648 * Clean and free the pages, as appropriate. All references to the 649 * object are gone, so we don't need to lock it. 650 */ 651 if (object->type == OBJT_VNODE) { 652 struct vnode *vp = (struct vnode *)object->handle; 653 654 /* 655 * Clean pages and flush buffers. 656 */ 657 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 658 VM_OBJECT_UNLOCK(object); 659 660 vinvalbuf(vp, V_SAVE, NULL, 0, 0); 661 662 VM_OBJECT_LOCK(object); 663 } 664 665 KASSERT(object->ref_count == 0, 666 ("vm_object_terminate: object with references, ref_count=%d", 667 object->ref_count)); 668 669 /* 670 * Now free any remaining pages. For internal objects, this also 671 * removes them from paging queues. Don't free wired pages, just 672 * remove them from the object. 673 */ 674 vm_page_lock_queues(); 675 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 676 KASSERT(!p->busy && (p->oflags & VPO_BUSY) == 0, 677 ("vm_object_terminate: freeing busy page %p " 678 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags)); 679 if (p->wire_count == 0) { 680 vm_page_free(p); 681 cnt.v_pfree++; 682 } else { 683 vm_page_remove(p); 684 } 685 } 686 vm_page_unlock_queues(); 687 688 #if VM_NRESERVLEVEL > 0 689 if (__predict_false(!LIST_EMPTY(&object->rvq))) 690 vm_reserv_break_all(object); 691 #endif 692 if (__predict_false(object->cache != NULL)) 693 vm_page_cache_free(object, 0, 0); 694 695 /* 696 * Let the pager know object is dead. 697 */ 698 vm_pager_deallocate(object); 699 VM_OBJECT_UNLOCK(object); 700 701 vm_object_destroy(object); 702 } 703 704 /* 705 * vm_object_page_clean 706 * 707 * Clean all dirty pages in the specified range of object. Leaves page 708 * on whatever queue it is currently on. If NOSYNC is set then do not 709 * write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC), 710 * leaving the object dirty. 711 * 712 * When stuffing pages asynchronously, allow clustering. XXX we need a 713 * synchronous clustering mode implementation. 714 * 715 * Odd semantics: if start == end, we clean everything. 716 * 717 * The object must be locked. 718 */ 719 void 720 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 721 { 722 vm_page_t p, np; 723 vm_pindex_t tstart, tend; 724 vm_pindex_t pi; 725 int clearobjflags; 726 int pagerflags; 727 int curgeneration; 728 729 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 730 if (object->type != OBJT_VNODE || 731 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 732 return; 733 734 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 735 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 736 737 vm_object_set_flag(object, OBJ_CLEANING); 738 739 tstart = start; 740 if (end == 0) { 741 tend = object->size; 742 } else { 743 tend = end; 744 } 745 746 vm_page_lock_queues(); 747 /* 748 * If the caller is smart and only msync()s a range he knows is 749 * dirty, we may be able to avoid an object scan. This results in 750 * a phenominal improvement in performance. We cannot do this 751 * as a matter of course because the object may be huge - e.g. 752 * the size might be in the gigabytes or terrabytes. 753 */ 754 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 755 vm_pindex_t tscan; 756 int scanlimit; 757 int scanreset; 758 759 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 760 if (scanreset < 16) 761 scanreset = 16; 762 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 763 764 scanlimit = scanreset; 765 tscan = tstart; 766 while (tscan < tend) { 767 curgeneration = object->generation; 768 p = vm_page_lookup(object, tscan); 769 if (p == NULL || p->valid == 0) { 770 if (--scanlimit == 0) 771 break; 772 ++tscan; 773 continue; 774 } 775 vm_page_test_dirty(p); 776 if ((p->dirty & p->valid) == 0) { 777 if (--scanlimit == 0) 778 break; 779 ++tscan; 780 continue; 781 } 782 /* 783 * If we have been asked to skip nosync pages and 784 * this is a nosync page, we can't continue. 785 */ 786 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 787 if (--scanlimit == 0) 788 break; 789 ++tscan; 790 continue; 791 } 792 scanlimit = scanreset; 793 794 /* 795 * This returns 0 if it was unable to busy the first 796 * page (i.e. had to sleep). 797 */ 798 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 799 } 800 801 /* 802 * If everything was dirty and we flushed it successfully, 803 * and the requested range is not the entire object, we 804 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 805 * return immediately. 806 */ 807 if (tscan >= tend && (tstart || tend < object->size)) { 808 vm_page_unlock_queues(); 809 vm_object_clear_flag(object, OBJ_CLEANING); 810 return; 811 } 812 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 813 } 814 815 /* 816 * Generally set CLEANCHK interlock and make the page read-only so 817 * we can then clear the object flags. 818 * 819 * However, if this is a nosync mmap then the object is likely to 820 * stay dirty so do not mess with the page and do not clear the 821 * object flags. 822 */ 823 clearobjflags = 1; 824 TAILQ_FOREACH(p, &object->memq, listq) { 825 p->oflags |= VPO_CLEANCHK; 826 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) 827 clearobjflags = 0; 828 else 829 pmap_remove_write(p); 830 } 831 832 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 833 struct vnode *vp; 834 835 vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY); 836 if (object->type == OBJT_VNODE && 837 (vp = (struct vnode *)object->handle) != NULL) { 838 VI_LOCK(vp); 839 if (vp->v_iflag & VI_OBJDIRTY) 840 vp->v_iflag &= ~VI_OBJDIRTY; 841 VI_UNLOCK(vp); 842 } 843 } 844 845 rescan: 846 curgeneration = object->generation; 847 848 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 849 int n; 850 851 np = TAILQ_NEXT(p, listq); 852 853 again: 854 pi = p->pindex; 855 if ((p->oflags & VPO_CLEANCHK) == 0 || 856 (pi < tstart) || (pi >= tend) || 857 p->valid == 0) { 858 p->oflags &= ~VPO_CLEANCHK; 859 continue; 860 } 861 862 vm_page_test_dirty(p); 863 if ((p->dirty & p->valid) == 0) { 864 p->oflags &= ~VPO_CLEANCHK; 865 continue; 866 } 867 868 /* 869 * If we have been asked to skip nosync pages and this is a 870 * nosync page, skip it. Note that the object flags were 871 * not cleared in this case so we do not have to set them. 872 */ 873 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 874 p->oflags &= ~VPO_CLEANCHK; 875 continue; 876 } 877 878 n = vm_object_page_collect_flush(object, p, 879 curgeneration, pagerflags); 880 if (n == 0) 881 goto rescan; 882 883 if (object->generation != curgeneration) 884 goto rescan; 885 886 /* 887 * Try to optimize the next page. If we can't we pick up 888 * our (random) scan where we left off. 889 */ 890 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 891 if ((p = vm_page_lookup(object, pi + n)) != NULL) 892 goto again; 893 } 894 } 895 vm_page_unlock_queues(); 896 #if 0 897 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 898 #endif 899 900 vm_object_clear_flag(object, OBJ_CLEANING); 901 return; 902 } 903 904 static int 905 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 906 { 907 int runlen; 908 int maxf; 909 int chkb; 910 int maxb; 911 int i; 912 vm_pindex_t pi; 913 vm_page_t maf[vm_pageout_page_count]; 914 vm_page_t mab[vm_pageout_page_count]; 915 vm_page_t ma[vm_pageout_page_count]; 916 917 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 918 pi = p->pindex; 919 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 920 vm_page_lock_queues(); 921 if (object->generation != curgeneration) { 922 return(0); 923 } 924 } 925 maxf = 0; 926 for(i = 1; i < vm_pageout_page_count; i++) { 927 vm_page_t tp; 928 929 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 930 if ((tp->oflags & VPO_BUSY) || 931 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 932 (tp->oflags & VPO_CLEANCHK) == 0) || 933 (tp->busy != 0)) 934 break; 935 vm_page_test_dirty(tp); 936 if ((tp->dirty & tp->valid) == 0) { 937 tp->oflags &= ~VPO_CLEANCHK; 938 break; 939 } 940 maf[ i - 1 ] = tp; 941 maxf++; 942 continue; 943 } 944 break; 945 } 946 947 maxb = 0; 948 chkb = vm_pageout_page_count - maxf; 949 if (chkb) { 950 for(i = 1; i < chkb;i++) { 951 vm_page_t tp; 952 953 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 954 if ((tp->oflags & VPO_BUSY) || 955 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 956 (tp->oflags & VPO_CLEANCHK) == 0) || 957 (tp->busy != 0)) 958 break; 959 vm_page_test_dirty(tp); 960 if ((tp->dirty & tp->valid) == 0) { 961 tp->oflags &= ~VPO_CLEANCHK; 962 break; 963 } 964 mab[ i - 1 ] = tp; 965 maxb++; 966 continue; 967 } 968 break; 969 } 970 } 971 972 for(i = 0; i < maxb; i++) { 973 int index = (maxb - i) - 1; 974 ma[index] = mab[i]; 975 ma[index]->oflags &= ~VPO_CLEANCHK; 976 } 977 p->oflags &= ~VPO_CLEANCHK; 978 ma[maxb] = p; 979 for(i = 0; i < maxf; i++) { 980 int index = (maxb + i) + 1; 981 ma[index] = maf[i]; 982 ma[index]->oflags &= ~VPO_CLEANCHK; 983 } 984 runlen = maxb + maxf + 1; 985 986 vm_pageout_flush(ma, runlen, pagerflags); 987 for (i = 0; i < runlen; i++) { 988 if (ma[i]->valid & ma[i]->dirty) { 989 pmap_remove_write(ma[i]); 990 ma[i]->oflags |= VPO_CLEANCHK; 991 992 /* 993 * maxf will end up being the actual number of pages 994 * we wrote out contiguously, non-inclusive of the 995 * first page. We do not count look-behind pages. 996 */ 997 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 998 maxf = i - maxb - 1; 999 } 1000 } 1001 return(maxf + 1); 1002 } 1003 1004 /* 1005 * Note that there is absolutely no sense in writing out 1006 * anonymous objects, so we track down the vnode object 1007 * to write out. 1008 * We invalidate (remove) all pages from the address space 1009 * for semantic correctness. 1010 * 1011 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1012 * may start out with a NULL object. 1013 */ 1014 void 1015 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1016 boolean_t syncio, boolean_t invalidate) 1017 { 1018 vm_object_t backing_object; 1019 struct vnode *vp; 1020 struct mount *mp; 1021 int flags; 1022 1023 if (object == NULL) 1024 return; 1025 VM_OBJECT_LOCK(object); 1026 while ((backing_object = object->backing_object) != NULL) { 1027 VM_OBJECT_LOCK(backing_object); 1028 offset += object->backing_object_offset; 1029 VM_OBJECT_UNLOCK(object); 1030 object = backing_object; 1031 if (object->size < OFF_TO_IDX(offset + size)) 1032 size = IDX_TO_OFF(object->size) - offset; 1033 } 1034 /* 1035 * Flush pages if writing is allowed, invalidate them 1036 * if invalidation requested. Pages undergoing I/O 1037 * will be ignored by vm_object_page_remove(). 1038 * 1039 * We cannot lock the vnode and then wait for paging 1040 * to complete without deadlocking against vm_fault. 1041 * Instead we simply call vm_object_page_remove() and 1042 * allow it to block internally on a page-by-page 1043 * basis when it encounters pages undergoing async 1044 * I/O. 1045 */ 1046 if (object->type == OBJT_VNODE && 1047 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1048 int vfslocked; 1049 vp = object->handle; 1050 VM_OBJECT_UNLOCK(object); 1051 (void) vn_start_write(vp, &mp, V_WAIT); 1052 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1053 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1054 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1055 flags |= invalidate ? OBJPC_INVAL : 0; 1056 VM_OBJECT_LOCK(object); 1057 vm_object_page_clean(object, 1058 OFF_TO_IDX(offset), 1059 OFF_TO_IDX(offset + size + PAGE_MASK), 1060 flags); 1061 VM_OBJECT_UNLOCK(object); 1062 VOP_UNLOCK(vp, 0); 1063 VFS_UNLOCK_GIANT(vfslocked); 1064 vn_finished_write(mp); 1065 VM_OBJECT_LOCK(object); 1066 } 1067 if ((object->type == OBJT_VNODE || 1068 object->type == OBJT_DEVICE) && invalidate) { 1069 boolean_t purge; 1070 purge = old_msync || (object->type == OBJT_DEVICE); 1071 vm_object_page_remove(object, 1072 OFF_TO_IDX(offset), 1073 OFF_TO_IDX(offset + size + PAGE_MASK), 1074 purge ? FALSE : TRUE); 1075 } 1076 VM_OBJECT_UNLOCK(object); 1077 } 1078 1079 /* 1080 * vm_object_madvise: 1081 * 1082 * Implements the madvise function at the object/page level. 1083 * 1084 * MADV_WILLNEED (any object) 1085 * 1086 * Activate the specified pages if they are resident. 1087 * 1088 * MADV_DONTNEED (any object) 1089 * 1090 * Deactivate the specified pages if they are resident. 1091 * 1092 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1093 * OBJ_ONEMAPPING only) 1094 * 1095 * Deactivate and clean the specified pages if they are 1096 * resident. This permits the process to reuse the pages 1097 * without faulting or the kernel to reclaim the pages 1098 * without I/O. 1099 */ 1100 void 1101 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1102 { 1103 vm_pindex_t end, tpindex; 1104 vm_object_t backing_object, tobject; 1105 vm_page_t m; 1106 1107 if (object == NULL) 1108 return; 1109 VM_OBJECT_LOCK(object); 1110 end = pindex + count; 1111 /* 1112 * Locate and adjust resident pages 1113 */ 1114 for (; pindex < end; pindex += 1) { 1115 relookup: 1116 tobject = object; 1117 tpindex = pindex; 1118 shadowlookup: 1119 /* 1120 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1121 * and those pages must be OBJ_ONEMAPPING. 1122 */ 1123 if (advise == MADV_FREE) { 1124 if ((tobject->type != OBJT_DEFAULT && 1125 tobject->type != OBJT_SWAP) || 1126 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1127 goto unlock_tobject; 1128 } 1129 } 1130 m = vm_page_lookup(tobject, tpindex); 1131 if (m == NULL && advise == MADV_WILLNEED) { 1132 /* 1133 * If the page is cached, reactivate it. 1134 */ 1135 m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED | 1136 VM_ALLOC_NOBUSY); 1137 } 1138 if (m == NULL) { 1139 /* 1140 * There may be swap even if there is no backing page 1141 */ 1142 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1143 swap_pager_freespace(tobject, tpindex, 1); 1144 /* 1145 * next object 1146 */ 1147 backing_object = tobject->backing_object; 1148 if (backing_object == NULL) 1149 goto unlock_tobject; 1150 VM_OBJECT_LOCK(backing_object); 1151 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1152 if (tobject != object) 1153 VM_OBJECT_UNLOCK(tobject); 1154 tobject = backing_object; 1155 goto shadowlookup; 1156 } 1157 /* 1158 * If the page is busy or not in a normal active state, 1159 * we skip it. If the page is not managed there are no 1160 * page queues to mess with. Things can break if we mess 1161 * with pages in any of the below states. 1162 */ 1163 vm_page_lock_queues(); 1164 if (m->hold_count || 1165 m->wire_count || 1166 (m->flags & PG_UNMANAGED) || 1167 m->valid != VM_PAGE_BITS_ALL) { 1168 vm_page_unlock_queues(); 1169 goto unlock_tobject; 1170 } 1171 if ((m->oflags & VPO_BUSY) || m->busy) { 1172 vm_page_flag_set(m, PG_REFERENCED); 1173 vm_page_unlock_queues(); 1174 if (object != tobject) 1175 VM_OBJECT_UNLOCK(object); 1176 m->oflags |= VPO_WANTED; 1177 msleep(m, VM_OBJECT_MTX(tobject), PDROP | PVM, "madvpo", 0); 1178 VM_OBJECT_LOCK(object); 1179 goto relookup; 1180 } 1181 if (advise == MADV_WILLNEED) { 1182 vm_page_activate(m); 1183 } else if (advise == MADV_DONTNEED) { 1184 vm_page_dontneed(m); 1185 } else if (advise == MADV_FREE) { 1186 /* 1187 * Mark the page clean. This will allow the page 1188 * to be freed up by the system. However, such pages 1189 * are often reused quickly by malloc()/free() 1190 * so we do not do anything that would cause 1191 * a page fault if we can help it. 1192 * 1193 * Specifically, we do not try to actually free 1194 * the page now nor do we try to put it in the 1195 * cache (which would cause a page fault on reuse). 1196 * 1197 * But we do make the page is freeable as we 1198 * can without actually taking the step of unmapping 1199 * it. 1200 */ 1201 pmap_clear_modify(m); 1202 m->dirty = 0; 1203 m->act_count = 0; 1204 vm_page_dontneed(m); 1205 } 1206 vm_page_unlock_queues(); 1207 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1208 swap_pager_freespace(tobject, tpindex, 1); 1209 unlock_tobject: 1210 if (tobject != object) 1211 VM_OBJECT_UNLOCK(tobject); 1212 } 1213 VM_OBJECT_UNLOCK(object); 1214 } 1215 1216 /* 1217 * vm_object_shadow: 1218 * 1219 * Create a new object which is backed by the 1220 * specified existing object range. The source 1221 * object reference is deallocated. 1222 * 1223 * The new object and offset into that object 1224 * are returned in the source parameters. 1225 */ 1226 void 1227 vm_object_shadow( 1228 vm_object_t *object, /* IN/OUT */ 1229 vm_ooffset_t *offset, /* IN/OUT */ 1230 vm_size_t length) 1231 { 1232 vm_object_t source; 1233 vm_object_t result; 1234 1235 source = *object; 1236 1237 /* 1238 * Don't create the new object if the old object isn't shared. 1239 */ 1240 if (source != NULL) { 1241 VM_OBJECT_LOCK(source); 1242 if (source->ref_count == 1 && 1243 source->handle == NULL && 1244 (source->type == OBJT_DEFAULT || 1245 source->type == OBJT_SWAP)) { 1246 VM_OBJECT_UNLOCK(source); 1247 return; 1248 } 1249 VM_OBJECT_UNLOCK(source); 1250 } 1251 1252 /* 1253 * Allocate a new object with the given length. 1254 */ 1255 result = vm_object_allocate(OBJT_DEFAULT, length); 1256 1257 /* 1258 * The new object shadows the source object, adding a reference to it. 1259 * Our caller changes his reference to point to the new object, 1260 * removing a reference to the source object. Net result: no change 1261 * of reference count. 1262 * 1263 * Try to optimize the result object's page color when shadowing 1264 * in order to maintain page coloring consistency in the combined 1265 * shadowed object. 1266 */ 1267 result->backing_object = source; 1268 /* 1269 * Store the offset into the source object, and fix up the offset into 1270 * the new object. 1271 */ 1272 result->backing_object_offset = *offset; 1273 if (source != NULL) { 1274 VM_OBJECT_LOCK(source); 1275 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1276 source->shadow_count++; 1277 source->generation++; 1278 #if VM_NRESERVLEVEL > 0 1279 result->flags |= source->flags & (OBJ_NEEDGIANT | OBJ_COLORED); 1280 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & 1281 ((1 << (VM_NFREEORDER - 1)) - 1); 1282 #else 1283 result->flags |= source->flags & OBJ_NEEDGIANT; 1284 #endif 1285 VM_OBJECT_UNLOCK(source); 1286 } 1287 1288 1289 /* 1290 * Return the new things 1291 */ 1292 *offset = 0; 1293 *object = result; 1294 } 1295 1296 /* 1297 * vm_object_split: 1298 * 1299 * Split the pages in a map entry into a new object. This affords 1300 * easier removal of unused pages, and keeps object inheritance from 1301 * being a negative impact on memory usage. 1302 */ 1303 void 1304 vm_object_split(vm_map_entry_t entry) 1305 { 1306 vm_page_t m, m_next; 1307 vm_object_t orig_object, new_object, source; 1308 vm_pindex_t idx, offidxstart; 1309 vm_size_t size; 1310 1311 orig_object = entry->object.vm_object; 1312 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1313 return; 1314 if (orig_object->ref_count <= 1) 1315 return; 1316 VM_OBJECT_UNLOCK(orig_object); 1317 1318 offidxstart = OFF_TO_IDX(entry->offset); 1319 size = atop(entry->end - entry->start); 1320 1321 /* 1322 * If swap_pager_copy() is later called, it will convert new_object 1323 * into a swap object. 1324 */ 1325 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1326 1327 /* 1328 * At this point, the new object is still private, so the order in 1329 * which the original and new objects are locked does not matter. 1330 */ 1331 VM_OBJECT_LOCK(new_object); 1332 VM_OBJECT_LOCK(orig_object); 1333 source = orig_object->backing_object; 1334 if (source != NULL) { 1335 VM_OBJECT_LOCK(source); 1336 if ((source->flags & OBJ_DEAD) != 0) { 1337 VM_OBJECT_UNLOCK(source); 1338 VM_OBJECT_UNLOCK(orig_object); 1339 VM_OBJECT_UNLOCK(new_object); 1340 vm_object_deallocate(new_object); 1341 VM_OBJECT_LOCK(orig_object); 1342 return; 1343 } 1344 LIST_INSERT_HEAD(&source->shadow_head, 1345 new_object, shadow_list); 1346 source->shadow_count++; 1347 source->generation++; 1348 vm_object_reference_locked(source); /* for new_object */ 1349 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1350 VM_OBJECT_UNLOCK(source); 1351 new_object->backing_object_offset = 1352 orig_object->backing_object_offset + entry->offset; 1353 new_object->backing_object = source; 1354 } 1355 new_object->flags |= orig_object->flags & OBJ_NEEDGIANT; 1356 retry: 1357 if ((m = TAILQ_FIRST(&orig_object->memq)) != NULL) { 1358 if (m->pindex < offidxstart) { 1359 m = vm_page_splay(offidxstart, orig_object->root); 1360 if ((orig_object->root = m)->pindex < offidxstart) 1361 m = TAILQ_NEXT(m, listq); 1362 } 1363 } 1364 vm_page_lock_queues(); 1365 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1366 m = m_next) { 1367 m_next = TAILQ_NEXT(m, listq); 1368 1369 /* 1370 * We must wait for pending I/O to complete before we can 1371 * rename the page. 1372 * 1373 * We do not have to VM_PROT_NONE the page as mappings should 1374 * not be changed by this operation. 1375 */ 1376 if ((m->oflags & VPO_BUSY) || m->busy) { 1377 vm_page_flag_set(m, PG_REFERENCED); 1378 vm_page_unlock_queues(); 1379 VM_OBJECT_UNLOCK(new_object); 1380 m->oflags |= VPO_WANTED; 1381 msleep(m, VM_OBJECT_MTX(orig_object), PVM, "spltwt", 0); 1382 VM_OBJECT_LOCK(new_object); 1383 goto retry; 1384 } 1385 vm_page_rename(m, new_object, idx); 1386 /* page automatically made dirty by rename and cache handled */ 1387 vm_page_busy(m); 1388 } 1389 vm_page_unlock_queues(); 1390 if (orig_object->type == OBJT_SWAP) { 1391 /* 1392 * swap_pager_copy() can sleep, in which case the orig_object's 1393 * and new_object's locks are released and reacquired. 1394 */ 1395 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1396 1397 /* 1398 * Transfer any cached pages from orig_object to new_object. 1399 */ 1400 if (__predict_false(orig_object->cache != NULL)) 1401 vm_page_cache_transfer(orig_object, offidxstart, 1402 new_object); 1403 } 1404 VM_OBJECT_UNLOCK(orig_object); 1405 TAILQ_FOREACH(m, &new_object->memq, listq) 1406 vm_page_wakeup(m); 1407 VM_OBJECT_UNLOCK(new_object); 1408 entry->object.vm_object = new_object; 1409 entry->offset = 0LL; 1410 vm_object_deallocate(orig_object); 1411 VM_OBJECT_LOCK(new_object); 1412 } 1413 1414 #define OBSC_TEST_ALL_SHADOWED 0x0001 1415 #define OBSC_COLLAPSE_NOWAIT 0x0002 1416 #define OBSC_COLLAPSE_WAIT 0x0004 1417 1418 static int 1419 vm_object_backing_scan(vm_object_t object, int op) 1420 { 1421 int r = 1; 1422 vm_page_t p; 1423 vm_object_t backing_object; 1424 vm_pindex_t backing_offset_index; 1425 1426 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1427 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1428 1429 backing_object = object->backing_object; 1430 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1431 1432 /* 1433 * Initial conditions 1434 */ 1435 if (op & OBSC_TEST_ALL_SHADOWED) { 1436 /* 1437 * We do not want to have to test for the existence of cache 1438 * or swap pages in the backing object. XXX but with the 1439 * new swapper this would be pretty easy to do. 1440 * 1441 * XXX what about anonymous MAP_SHARED memory that hasn't 1442 * been ZFOD faulted yet? If we do not test for this, the 1443 * shadow test may succeed! XXX 1444 */ 1445 if (backing_object->type != OBJT_DEFAULT) { 1446 return (0); 1447 } 1448 } 1449 if (op & OBSC_COLLAPSE_WAIT) { 1450 vm_object_set_flag(backing_object, OBJ_DEAD); 1451 } 1452 1453 /* 1454 * Our scan 1455 */ 1456 p = TAILQ_FIRST(&backing_object->memq); 1457 while (p) { 1458 vm_page_t next = TAILQ_NEXT(p, listq); 1459 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1460 1461 if (op & OBSC_TEST_ALL_SHADOWED) { 1462 vm_page_t pp; 1463 1464 /* 1465 * Ignore pages outside the parent object's range 1466 * and outside the parent object's mapping of the 1467 * backing object. 1468 * 1469 * note that we do not busy the backing object's 1470 * page. 1471 */ 1472 if ( 1473 p->pindex < backing_offset_index || 1474 new_pindex >= object->size 1475 ) { 1476 p = next; 1477 continue; 1478 } 1479 1480 /* 1481 * See if the parent has the page or if the parent's 1482 * object pager has the page. If the parent has the 1483 * page but the page is not valid, the parent's 1484 * object pager must have the page. 1485 * 1486 * If this fails, the parent does not completely shadow 1487 * the object and we might as well give up now. 1488 */ 1489 1490 pp = vm_page_lookup(object, new_pindex); 1491 if ( 1492 (pp == NULL || pp->valid == 0) && 1493 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1494 ) { 1495 r = 0; 1496 break; 1497 } 1498 } 1499 1500 /* 1501 * Check for busy page 1502 */ 1503 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1504 vm_page_t pp; 1505 1506 if (op & OBSC_COLLAPSE_NOWAIT) { 1507 if ((p->oflags & VPO_BUSY) || 1508 !p->valid || 1509 p->busy) { 1510 p = next; 1511 continue; 1512 } 1513 } else if (op & OBSC_COLLAPSE_WAIT) { 1514 if ((p->oflags & VPO_BUSY) || p->busy) { 1515 vm_page_lock_queues(); 1516 vm_page_flag_set(p, PG_REFERENCED); 1517 vm_page_unlock_queues(); 1518 VM_OBJECT_UNLOCK(object); 1519 p->oflags |= VPO_WANTED; 1520 msleep(p, VM_OBJECT_MTX(backing_object), 1521 PDROP | PVM, "vmocol", 0); 1522 VM_OBJECT_LOCK(object); 1523 VM_OBJECT_LOCK(backing_object); 1524 /* 1525 * If we slept, anything could have 1526 * happened. Since the object is 1527 * marked dead, the backing offset 1528 * should not have changed so we 1529 * just restart our scan. 1530 */ 1531 p = TAILQ_FIRST(&backing_object->memq); 1532 continue; 1533 } 1534 } 1535 1536 KASSERT( 1537 p->object == backing_object, 1538 ("vm_object_backing_scan: object mismatch") 1539 ); 1540 1541 /* 1542 * Destroy any associated swap 1543 */ 1544 if (backing_object->type == OBJT_SWAP) { 1545 swap_pager_freespace( 1546 backing_object, 1547 p->pindex, 1548 1 1549 ); 1550 } 1551 1552 if ( 1553 p->pindex < backing_offset_index || 1554 new_pindex >= object->size 1555 ) { 1556 /* 1557 * Page is out of the parent object's range, we 1558 * can simply destroy it. 1559 */ 1560 vm_page_lock_queues(); 1561 KASSERT(!pmap_page_is_mapped(p), 1562 ("freeing mapped page %p", p)); 1563 if (p->wire_count == 0) 1564 vm_page_free(p); 1565 else 1566 vm_page_remove(p); 1567 vm_page_unlock_queues(); 1568 p = next; 1569 continue; 1570 } 1571 1572 pp = vm_page_lookup(object, new_pindex); 1573 if ( 1574 pp != NULL || 1575 vm_pager_has_page(object, new_pindex, NULL, NULL) 1576 ) { 1577 /* 1578 * page already exists in parent OR swap exists 1579 * for this location in the parent. Destroy 1580 * the original page from the backing object. 1581 * 1582 * Leave the parent's page alone 1583 */ 1584 vm_page_lock_queues(); 1585 KASSERT(!pmap_page_is_mapped(p), 1586 ("freeing mapped page %p", p)); 1587 if (p->wire_count == 0) 1588 vm_page_free(p); 1589 else 1590 vm_page_remove(p); 1591 vm_page_unlock_queues(); 1592 p = next; 1593 continue; 1594 } 1595 1596 #if VM_NRESERVLEVEL > 0 1597 /* 1598 * Rename the reservation. 1599 */ 1600 vm_reserv_rename(p, object, backing_object, 1601 backing_offset_index); 1602 #endif 1603 1604 /* 1605 * Page does not exist in parent, rename the 1606 * page from the backing object to the main object. 1607 * 1608 * If the page was mapped to a process, it can remain 1609 * mapped through the rename. 1610 */ 1611 vm_page_lock_queues(); 1612 vm_page_rename(p, object, new_pindex); 1613 vm_page_unlock_queues(); 1614 /* page automatically made dirty by rename */ 1615 } 1616 p = next; 1617 } 1618 return (r); 1619 } 1620 1621 1622 /* 1623 * this version of collapse allows the operation to occur earlier and 1624 * when paging_in_progress is true for an object... This is not a complete 1625 * operation, but should plug 99.9% of the rest of the leaks. 1626 */ 1627 static void 1628 vm_object_qcollapse(vm_object_t object) 1629 { 1630 vm_object_t backing_object = object->backing_object; 1631 1632 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1633 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1634 1635 if (backing_object->ref_count != 1) 1636 return; 1637 1638 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1639 } 1640 1641 /* 1642 * vm_object_collapse: 1643 * 1644 * Collapse an object with the object backing it. 1645 * Pages in the backing object are moved into the 1646 * parent, and the backing object is deallocated. 1647 */ 1648 void 1649 vm_object_collapse(vm_object_t object) 1650 { 1651 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1652 1653 while (TRUE) { 1654 vm_object_t backing_object; 1655 1656 /* 1657 * Verify that the conditions are right for collapse: 1658 * 1659 * The object exists and the backing object exists. 1660 */ 1661 if ((backing_object = object->backing_object) == NULL) 1662 break; 1663 1664 /* 1665 * we check the backing object first, because it is most likely 1666 * not collapsable. 1667 */ 1668 VM_OBJECT_LOCK(backing_object); 1669 if (backing_object->handle != NULL || 1670 (backing_object->type != OBJT_DEFAULT && 1671 backing_object->type != OBJT_SWAP) || 1672 (backing_object->flags & OBJ_DEAD) || 1673 object->handle != NULL || 1674 (object->type != OBJT_DEFAULT && 1675 object->type != OBJT_SWAP) || 1676 (object->flags & OBJ_DEAD)) { 1677 VM_OBJECT_UNLOCK(backing_object); 1678 break; 1679 } 1680 1681 if ( 1682 object->paging_in_progress != 0 || 1683 backing_object->paging_in_progress != 0 1684 ) { 1685 vm_object_qcollapse(object); 1686 VM_OBJECT_UNLOCK(backing_object); 1687 break; 1688 } 1689 /* 1690 * We know that we can either collapse the backing object (if 1691 * the parent is the only reference to it) or (perhaps) have 1692 * the parent bypass the object if the parent happens to shadow 1693 * all the resident pages in the entire backing object. 1694 * 1695 * This is ignoring pager-backed pages such as swap pages. 1696 * vm_object_backing_scan fails the shadowing test in this 1697 * case. 1698 */ 1699 if (backing_object->ref_count == 1) { 1700 /* 1701 * If there is exactly one reference to the backing 1702 * object, we can collapse it into the parent. 1703 */ 1704 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1705 1706 #if VM_NRESERVLEVEL > 0 1707 /* 1708 * Break any reservations from backing_object. 1709 */ 1710 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1711 vm_reserv_break_all(backing_object); 1712 #endif 1713 1714 /* 1715 * Move the pager from backing_object to object. 1716 */ 1717 if (backing_object->type == OBJT_SWAP) { 1718 /* 1719 * swap_pager_copy() can sleep, in which case 1720 * the backing_object's and object's locks are 1721 * released and reacquired. 1722 */ 1723 swap_pager_copy( 1724 backing_object, 1725 object, 1726 OFF_TO_IDX(object->backing_object_offset), TRUE); 1727 1728 /* 1729 * Free any cached pages from backing_object. 1730 */ 1731 if (__predict_false(backing_object->cache != NULL)) 1732 vm_page_cache_free(backing_object, 0, 0); 1733 } 1734 /* 1735 * Object now shadows whatever backing_object did. 1736 * Note that the reference to 1737 * backing_object->backing_object moves from within 1738 * backing_object to within object. 1739 */ 1740 LIST_REMOVE(object, shadow_list); 1741 backing_object->shadow_count--; 1742 backing_object->generation++; 1743 if (backing_object->backing_object) { 1744 VM_OBJECT_LOCK(backing_object->backing_object); 1745 LIST_REMOVE(backing_object, shadow_list); 1746 LIST_INSERT_HEAD( 1747 &backing_object->backing_object->shadow_head, 1748 object, shadow_list); 1749 /* 1750 * The shadow_count has not changed. 1751 */ 1752 backing_object->backing_object->generation++; 1753 VM_OBJECT_UNLOCK(backing_object->backing_object); 1754 } 1755 object->backing_object = backing_object->backing_object; 1756 object->backing_object_offset += 1757 backing_object->backing_object_offset; 1758 1759 /* 1760 * Discard backing_object. 1761 * 1762 * Since the backing object has no pages, no pager left, 1763 * and no object references within it, all that is 1764 * necessary is to dispose of it. 1765 */ 1766 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1767 VM_OBJECT_UNLOCK(backing_object); 1768 1769 mtx_lock(&vm_object_list_mtx); 1770 TAILQ_REMOVE( 1771 &vm_object_list, 1772 backing_object, 1773 object_list 1774 ); 1775 mtx_unlock(&vm_object_list_mtx); 1776 1777 uma_zfree(obj_zone, backing_object); 1778 1779 object_collapses++; 1780 } else { 1781 vm_object_t new_backing_object; 1782 1783 /* 1784 * If we do not entirely shadow the backing object, 1785 * there is nothing we can do so we give up. 1786 */ 1787 if (object->resident_page_count != object->size && 1788 vm_object_backing_scan(object, 1789 OBSC_TEST_ALL_SHADOWED) == 0) { 1790 VM_OBJECT_UNLOCK(backing_object); 1791 break; 1792 } 1793 1794 /* 1795 * Make the parent shadow the next object in the 1796 * chain. Deallocating backing_object will not remove 1797 * it, since its reference count is at least 2. 1798 */ 1799 LIST_REMOVE(object, shadow_list); 1800 backing_object->shadow_count--; 1801 backing_object->generation++; 1802 1803 new_backing_object = backing_object->backing_object; 1804 if ((object->backing_object = new_backing_object) != NULL) { 1805 VM_OBJECT_LOCK(new_backing_object); 1806 LIST_INSERT_HEAD( 1807 &new_backing_object->shadow_head, 1808 object, 1809 shadow_list 1810 ); 1811 new_backing_object->shadow_count++; 1812 new_backing_object->generation++; 1813 vm_object_reference_locked(new_backing_object); 1814 VM_OBJECT_UNLOCK(new_backing_object); 1815 object->backing_object_offset += 1816 backing_object->backing_object_offset; 1817 } 1818 1819 /* 1820 * Drop the reference count on backing_object. Since 1821 * its ref_count was at least 2, it will not vanish. 1822 */ 1823 backing_object->ref_count--; 1824 VM_OBJECT_UNLOCK(backing_object); 1825 object_bypasses++; 1826 } 1827 1828 /* 1829 * Try again with this object's new backing object. 1830 */ 1831 } 1832 } 1833 1834 /* 1835 * vm_object_page_remove: 1836 * 1837 * For the given object, either frees or invalidates each of the 1838 * specified pages. In general, a page is freed. However, if a 1839 * page is wired for any reason other than the existence of a 1840 * managed, wired mapping, then it may be invalidated but not 1841 * removed from the object. Pages are specified by the given 1842 * range ["start", "end") and Boolean "clean_only". As a 1843 * special case, if "end" is zero, then the range extends from 1844 * "start" to the end of the object. If "clean_only" is TRUE, 1845 * then only the non-dirty pages within the specified range are 1846 * affected. 1847 * 1848 * In general, this operation should only be performed on objects 1849 * that contain managed pages. There are two exceptions. First, 1850 * it may be performed on the kernel and kmem objects. Second, 1851 * it may be used by msync(..., MS_INVALIDATE) to invalidate 1852 * device-backed pages. 1853 * 1854 * The object must be locked. 1855 */ 1856 void 1857 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1858 boolean_t clean_only) 1859 { 1860 vm_page_t p, next; 1861 int wirings; 1862 1863 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1864 if (object->resident_page_count == 0) 1865 goto skipmemq; 1866 1867 /* 1868 * Since physically-backed objects do not use managed pages, we can't 1869 * remove pages from the object (we must instead remove the page 1870 * references, and then destroy the object). 1871 */ 1872 KASSERT(object->type != OBJT_PHYS || object == kernel_object || 1873 object == kmem_object, 1874 ("attempt to remove pages from a physical object")); 1875 1876 vm_object_pip_add(object, 1); 1877 again: 1878 vm_page_lock_queues(); 1879 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1880 if (p->pindex < start) { 1881 p = vm_page_splay(start, object->root); 1882 if ((object->root = p)->pindex < start) 1883 p = TAILQ_NEXT(p, listq); 1884 } 1885 } 1886 /* 1887 * Assert: the variable p is either (1) the page with the 1888 * least pindex greater than or equal to the parameter pindex 1889 * or (2) NULL. 1890 */ 1891 for (; 1892 p != NULL && (p->pindex < end || end == 0); 1893 p = next) { 1894 next = TAILQ_NEXT(p, listq); 1895 1896 /* 1897 * If the page is wired for any reason besides the 1898 * existence of managed, wired mappings, then it cannot 1899 * be freed. For example, fictitious pages, which 1900 * represent device memory, are inherently wired and 1901 * cannot be freed. They can, however, be invalidated 1902 * if "clean_only" is FALSE. 1903 */ 1904 if ((wirings = p->wire_count) != 0 && 1905 (wirings = pmap_page_wired_mappings(p)) != p->wire_count) { 1906 /* Fictitious pages do not have managed mappings. */ 1907 if ((p->flags & PG_FICTITIOUS) == 0) 1908 pmap_remove_all(p); 1909 /* Account for removal of managed, wired mappings. */ 1910 p->wire_count -= wirings; 1911 if (!clean_only) 1912 p->valid = 0; 1913 continue; 1914 } 1915 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1916 goto again; 1917 KASSERT((p->flags & PG_FICTITIOUS) == 0, 1918 ("vm_object_page_remove: page %p is fictitious", p)); 1919 if (clean_only && p->valid) { 1920 pmap_remove_write(p); 1921 if (p->valid & p->dirty) 1922 continue; 1923 } 1924 pmap_remove_all(p); 1925 /* Account for removal of managed, wired mappings. */ 1926 if (wirings != 0) 1927 p->wire_count -= wirings; 1928 vm_page_free(p); 1929 } 1930 vm_page_unlock_queues(); 1931 vm_object_pip_wakeup(object); 1932 skipmemq: 1933 if (__predict_false(object->cache != NULL)) 1934 vm_page_cache_free(object, start, end); 1935 } 1936 1937 /* 1938 * Routine: vm_object_coalesce 1939 * Function: Coalesces two objects backing up adjoining 1940 * regions of memory into a single object. 1941 * 1942 * returns TRUE if objects were combined. 1943 * 1944 * NOTE: Only works at the moment if the second object is NULL - 1945 * if it's not, which object do we lock first? 1946 * 1947 * Parameters: 1948 * prev_object First object to coalesce 1949 * prev_offset Offset into prev_object 1950 * prev_size Size of reference to prev_object 1951 * next_size Size of reference to the second object 1952 * 1953 * Conditions: 1954 * The object must *not* be locked. 1955 */ 1956 boolean_t 1957 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 1958 vm_size_t prev_size, vm_size_t next_size) 1959 { 1960 vm_pindex_t next_pindex; 1961 1962 if (prev_object == NULL) 1963 return (TRUE); 1964 VM_OBJECT_LOCK(prev_object); 1965 if (prev_object->type != OBJT_DEFAULT && 1966 prev_object->type != OBJT_SWAP) { 1967 VM_OBJECT_UNLOCK(prev_object); 1968 return (FALSE); 1969 } 1970 1971 /* 1972 * Try to collapse the object first 1973 */ 1974 vm_object_collapse(prev_object); 1975 1976 /* 1977 * Can't coalesce if: . more than one reference . paged out . shadows 1978 * another object . has a copy elsewhere (any of which mean that the 1979 * pages not mapped to prev_entry may be in use anyway) 1980 */ 1981 if (prev_object->backing_object != NULL) { 1982 VM_OBJECT_UNLOCK(prev_object); 1983 return (FALSE); 1984 } 1985 1986 prev_size >>= PAGE_SHIFT; 1987 next_size >>= PAGE_SHIFT; 1988 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 1989 1990 if ((prev_object->ref_count > 1) && 1991 (prev_object->size != next_pindex)) { 1992 VM_OBJECT_UNLOCK(prev_object); 1993 return (FALSE); 1994 } 1995 1996 /* 1997 * Remove any pages that may still be in the object from a previous 1998 * deallocation. 1999 */ 2000 if (next_pindex < prev_object->size) { 2001 vm_object_page_remove(prev_object, 2002 next_pindex, 2003 next_pindex + next_size, FALSE); 2004 if (prev_object->type == OBJT_SWAP) 2005 swap_pager_freespace(prev_object, 2006 next_pindex, next_size); 2007 } 2008 2009 /* 2010 * Extend the object if necessary. 2011 */ 2012 if (next_pindex + next_size > prev_object->size) 2013 prev_object->size = next_pindex + next_size; 2014 2015 VM_OBJECT_UNLOCK(prev_object); 2016 return (TRUE); 2017 } 2018 2019 void 2020 vm_object_set_writeable_dirty(vm_object_t object) 2021 { 2022 struct vnode *vp; 2023 2024 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2025 if ((object->flags & OBJ_MIGHTBEDIRTY) != 0) 2026 return; 2027 vm_object_set_flag(object, OBJ_MIGHTBEDIRTY); 2028 if (object->type == OBJT_VNODE && 2029 (vp = (struct vnode *)object->handle) != NULL) { 2030 VI_LOCK(vp); 2031 vp->v_iflag |= VI_OBJDIRTY; 2032 VI_UNLOCK(vp); 2033 } 2034 } 2035 2036 #include "opt_ddb.h" 2037 #ifdef DDB 2038 #include <sys/kernel.h> 2039 2040 #include <sys/cons.h> 2041 2042 #include <ddb/ddb.h> 2043 2044 static int 2045 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2046 { 2047 vm_map_t tmpm; 2048 vm_map_entry_t tmpe; 2049 vm_object_t obj; 2050 int entcount; 2051 2052 if (map == 0) 2053 return 0; 2054 2055 if (entry == 0) { 2056 tmpe = map->header.next; 2057 entcount = map->nentries; 2058 while (entcount-- && (tmpe != &map->header)) { 2059 if (_vm_object_in_map(map, object, tmpe)) { 2060 return 1; 2061 } 2062 tmpe = tmpe->next; 2063 } 2064 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2065 tmpm = entry->object.sub_map; 2066 tmpe = tmpm->header.next; 2067 entcount = tmpm->nentries; 2068 while (entcount-- && tmpe != &tmpm->header) { 2069 if (_vm_object_in_map(tmpm, object, tmpe)) { 2070 return 1; 2071 } 2072 tmpe = tmpe->next; 2073 } 2074 } else if ((obj = entry->object.vm_object) != NULL) { 2075 for (; obj; obj = obj->backing_object) 2076 if (obj == object) { 2077 return 1; 2078 } 2079 } 2080 return 0; 2081 } 2082 2083 static int 2084 vm_object_in_map(vm_object_t object) 2085 { 2086 struct proc *p; 2087 2088 /* sx_slock(&allproc_lock); */ 2089 FOREACH_PROC_IN_SYSTEM(p) { 2090 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2091 continue; 2092 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2093 /* sx_sunlock(&allproc_lock); */ 2094 return 1; 2095 } 2096 } 2097 /* sx_sunlock(&allproc_lock); */ 2098 if (_vm_object_in_map(kernel_map, object, 0)) 2099 return 1; 2100 if (_vm_object_in_map(kmem_map, object, 0)) 2101 return 1; 2102 if (_vm_object_in_map(pager_map, object, 0)) 2103 return 1; 2104 if (_vm_object_in_map(buffer_map, object, 0)) 2105 return 1; 2106 return 0; 2107 } 2108 2109 DB_SHOW_COMMAND(vmochk, vm_object_check) 2110 { 2111 vm_object_t object; 2112 2113 /* 2114 * make sure that internal objs are in a map somewhere 2115 * and none have zero ref counts. 2116 */ 2117 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2118 if (object->handle == NULL && 2119 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2120 if (object->ref_count == 0) { 2121 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2122 (long)object->size); 2123 } 2124 if (!vm_object_in_map(object)) { 2125 db_printf( 2126 "vmochk: internal obj is not in a map: " 2127 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2128 object->ref_count, (u_long)object->size, 2129 (u_long)object->size, 2130 (void *)object->backing_object); 2131 } 2132 } 2133 } 2134 } 2135 2136 /* 2137 * vm_object_print: [ debug ] 2138 */ 2139 DB_SHOW_COMMAND(object, vm_object_print_static) 2140 { 2141 /* XXX convert args. */ 2142 vm_object_t object = (vm_object_t)addr; 2143 boolean_t full = have_addr; 2144 2145 vm_page_t p; 2146 2147 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2148 #define count was_count 2149 2150 int count; 2151 2152 if (object == NULL) 2153 return; 2154 2155 db_iprintf( 2156 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n", 2157 object, (int)object->type, (uintmax_t)object->size, 2158 object->resident_page_count, object->ref_count, object->flags); 2159 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2160 object->shadow_count, 2161 object->backing_object ? object->backing_object->ref_count : 0, 2162 object->backing_object, (uintmax_t)object->backing_object_offset); 2163 2164 if (!full) 2165 return; 2166 2167 db_indent += 2; 2168 count = 0; 2169 TAILQ_FOREACH(p, &object->memq, listq) { 2170 if (count == 0) 2171 db_iprintf("memory:="); 2172 else if (count == 6) { 2173 db_printf("\n"); 2174 db_iprintf(" ..."); 2175 count = 0; 2176 } else 2177 db_printf(","); 2178 count++; 2179 2180 db_printf("(off=0x%jx,page=0x%jx)", 2181 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2182 } 2183 if (count != 0) 2184 db_printf("\n"); 2185 db_indent -= 2; 2186 } 2187 2188 /* XXX. */ 2189 #undef count 2190 2191 /* XXX need this non-static entry for calling from vm_map_print. */ 2192 void 2193 vm_object_print( 2194 /* db_expr_t */ long addr, 2195 boolean_t have_addr, 2196 /* db_expr_t */ long count, 2197 char *modif) 2198 { 2199 vm_object_print_static(addr, have_addr, count, modif); 2200 } 2201 2202 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2203 { 2204 vm_object_t object; 2205 int nl = 0; 2206 int c; 2207 2208 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2209 vm_pindex_t idx, fidx; 2210 vm_pindex_t osize; 2211 vm_paddr_t pa = -1; 2212 int rcount; 2213 vm_page_t m; 2214 2215 db_printf("new object: %p\n", (void *)object); 2216 if (nl > 18) { 2217 c = cngetc(); 2218 if (c != ' ') 2219 return; 2220 nl = 0; 2221 } 2222 nl++; 2223 rcount = 0; 2224 fidx = 0; 2225 osize = object->size; 2226 if (osize > 128) 2227 osize = 128; 2228 for (idx = 0; idx < osize; idx++) { 2229 m = vm_page_lookup(object, idx); 2230 if (m == NULL) { 2231 if (rcount) { 2232 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2233 (long)fidx, rcount, (long)pa); 2234 if (nl > 18) { 2235 c = cngetc(); 2236 if (c != ' ') 2237 return; 2238 nl = 0; 2239 } 2240 nl++; 2241 rcount = 0; 2242 } 2243 continue; 2244 } 2245 2246 2247 if (rcount && 2248 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2249 ++rcount; 2250 continue; 2251 } 2252 if (rcount) { 2253 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2254 (long)fidx, rcount, (long)pa); 2255 if (nl > 18) { 2256 c = cngetc(); 2257 if (c != ' ') 2258 return; 2259 nl = 0; 2260 } 2261 nl++; 2262 } 2263 fidx = idx; 2264 pa = VM_PAGE_TO_PHYS(m); 2265 rcount = 1; 2266 } 2267 if (rcount) { 2268 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2269 (long)fidx, rcount, (long)pa); 2270 if (nl > 18) { 2271 c = cngetc(); 2272 if (c != ' ') 2273 return; 2274 nl = 0; 2275 } 2276 nl++; 2277 } 2278 } 2279 } 2280 #endif /* DDB */ 2281