vm_object.c revision 209685
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: head/sys/vm/vm_object.c 209685 2010-07-04 11:13:33Z kib $"); 67 68#include "opt_vm.h" 69 70#include <sys/param.h> 71#include <sys/systm.h> 72#include <sys/lock.h> 73#include <sys/mman.h> 74#include <sys/mount.h> 75#include <sys/kernel.h> 76#include <sys/sysctl.h> 77#include <sys/mutex.h> 78#include <sys/proc.h> /* for curproc, pageproc */ 79#include <sys/socket.h> 80#include <sys/resourcevar.h> 81#include <sys/vnode.h> 82#include <sys/vmmeter.h> 83#include <sys/sx.h> 84 85#include <vm/vm.h> 86#include <vm/vm_param.h> 87#include <vm/pmap.h> 88#include <vm/vm_map.h> 89#include <vm/vm_object.h> 90#include <vm/vm_page.h> 91#include <vm/vm_pageout.h> 92#include <vm/vm_pager.h> 93#include <vm/swap_pager.h> 94#include <vm/vm_kern.h> 95#include <vm/vm_extern.h> 96#include <vm/vm_reserv.h> 97#include <vm/uma.h> 98 99#define EASY_SCAN_FACTOR 8 100 101#define MSYNC_FLUSH_HARDSEQ 0x01 102#define MSYNC_FLUSH_SOFTSEQ 0x02 103 104/* 105 * msync / VM object flushing optimizations 106 */ 107static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 108SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, CTLFLAG_RW, &msync_flush_flags, 0, 109 "Enable sequential iteration optimization"); 110 111static int old_msync; 112SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 113 "Use old (insecure) msync behavior"); 114 115static void vm_object_qcollapse(vm_object_t object); 116static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 117static void vm_object_vndeallocate(vm_object_t object); 118 119/* 120 * Virtual memory objects maintain the actual data 121 * associated with allocated virtual memory. A given 122 * page of memory exists within exactly one object. 123 * 124 * An object is only deallocated when all "references" 125 * are given up. Only one "reference" to a given 126 * region of an object should be writeable. 127 * 128 * Associated with each object is a list of all resident 129 * memory pages belonging to that object; this list is 130 * maintained by the "vm_page" module, and locked by the object's 131 * lock. 132 * 133 * Each object also records a "pager" routine which is 134 * used to retrieve (and store) pages to the proper backing 135 * storage. In addition, objects may be backed by other 136 * objects from which they were virtual-copied. 137 * 138 * The only items within the object structure which are 139 * modified after time of creation are: 140 * reference count locked by object's lock 141 * pager routine locked by object's lock 142 * 143 */ 144 145struct object_q vm_object_list; 146struct mtx vm_object_list_mtx; /* lock for object list and count */ 147 148struct vm_object kernel_object_store; 149struct vm_object kmem_object_store; 150 151SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0, "VM object stats"); 152 153static long object_collapses; 154SYSCTL_LONG(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD, 155 &object_collapses, 0, "VM object collapses"); 156 157static long object_bypasses; 158SYSCTL_LONG(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD, 159 &object_bypasses, 0, "VM object bypasses"); 160 161static uma_zone_t obj_zone; 162 163static int vm_object_zinit(void *mem, int size, int flags); 164 165#ifdef INVARIANTS 166static void vm_object_zdtor(void *mem, int size, void *arg); 167 168static void 169vm_object_zdtor(void *mem, int size, void *arg) 170{ 171 vm_object_t object; 172 173 object = (vm_object_t)mem; 174 KASSERT(TAILQ_EMPTY(&object->memq), 175 ("object %p has resident pages", 176 object)); 177#if VM_NRESERVLEVEL > 0 178 KASSERT(LIST_EMPTY(&object->rvq), 179 ("object %p has reservations", 180 object)); 181#endif 182 KASSERT(object->cache == NULL, 183 ("object %p has cached pages", 184 object)); 185 KASSERT(object->paging_in_progress == 0, 186 ("object %p paging_in_progress = %d", 187 object, object->paging_in_progress)); 188 KASSERT(object->resident_page_count == 0, 189 ("object %p resident_page_count = %d", 190 object, object->resident_page_count)); 191 KASSERT(object->shadow_count == 0, 192 ("object %p shadow_count = %d", 193 object, object->shadow_count)); 194} 195#endif 196 197static int 198vm_object_zinit(void *mem, int size, int flags) 199{ 200 vm_object_t object; 201 202 object = (vm_object_t)mem; 203 bzero(&object->mtx, sizeof(object->mtx)); 204 VM_OBJECT_LOCK_INIT(object, "standard object"); 205 206 /* These are true for any object that has been freed */ 207 object->paging_in_progress = 0; 208 object->resident_page_count = 0; 209 object->shadow_count = 0; 210 return (0); 211} 212 213void 214_vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object) 215{ 216 217 TAILQ_INIT(&object->memq); 218 LIST_INIT(&object->shadow_head); 219 220 object->root = NULL; 221 object->type = type; 222 object->size = size; 223 object->generation = 1; 224 object->ref_count = 1; 225 object->memattr = VM_MEMATTR_DEFAULT; 226 object->flags = 0; 227 object->uip = NULL; 228 object->charge = 0; 229 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 230 object->flags = OBJ_ONEMAPPING; 231 object->pg_color = 0; 232 object->handle = NULL; 233 object->backing_object = NULL; 234 object->backing_object_offset = (vm_ooffset_t) 0; 235#if VM_NRESERVLEVEL > 0 236 LIST_INIT(&object->rvq); 237#endif 238 object->cache = NULL; 239 240 mtx_lock(&vm_object_list_mtx); 241 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 242 mtx_unlock(&vm_object_list_mtx); 243} 244 245/* 246 * vm_object_init: 247 * 248 * Initialize the VM objects module. 249 */ 250void 251vm_object_init(void) 252{ 253 TAILQ_INIT(&vm_object_list); 254 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 255 256 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object"); 257 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 258 kernel_object); 259#if VM_NRESERVLEVEL > 0 260 kernel_object->flags |= OBJ_COLORED; 261 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 262#endif 263 264 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object"); 265 _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 266 kmem_object); 267#if VM_NRESERVLEVEL > 0 268 kmem_object->flags |= OBJ_COLORED; 269 kmem_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS); 270#endif 271 272 /* 273 * The lock portion of struct vm_object must be type stable due 274 * to vm_pageout_fallback_object_lock locking a vm object 275 * without holding any references to it. 276 */ 277 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 278#ifdef INVARIANTS 279 vm_object_zdtor, 280#else 281 NULL, 282#endif 283 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 284} 285 286void 287vm_object_clear_flag(vm_object_t object, u_short bits) 288{ 289 290 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 291 object->flags &= ~bits; 292} 293 294/* 295 * Sets the default memory attribute for the specified object. Pages 296 * that are allocated to this object are by default assigned this memory 297 * attribute. 298 * 299 * Presently, this function must be called before any pages are allocated 300 * to the object. In the future, this requirement may be relaxed for 301 * "default" and "swap" objects. 302 */ 303int 304vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr) 305{ 306 307 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 308 switch (object->type) { 309 case OBJT_DEFAULT: 310 case OBJT_DEVICE: 311 case OBJT_PHYS: 312 case OBJT_SG: 313 case OBJT_SWAP: 314 case OBJT_VNODE: 315 if (!TAILQ_EMPTY(&object->memq)) 316 return (KERN_FAILURE); 317 break; 318 case OBJT_DEAD: 319 return (KERN_INVALID_ARGUMENT); 320 } 321 object->memattr = memattr; 322 return (KERN_SUCCESS); 323} 324 325void 326vm_object_pip_add(vm_object_t object, short i) 327{ 328 329 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 330 object->paging_in_progress += i; 331} 332 333void 334vm_object_pip_subtract(vm_object_t object, short i) 335{ 336 337 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 338 object->paging_in_progress -= i; 339} 340 341void 342vm_object_pip_wakeup(vm_object_t object) 343{ 344 345 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 346 object->paging_in_progress--; 347 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 348 vm_object_clear_flag(object, OBJ_PIPWNT); 349 wakeup(object); 350 } 351} 352 353void 354vm_object_pip_wakeupn(vm_object_t object, short i) 355{ 356 357 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 358 if (i) 359 object->paging_in_progress -= i; 360 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 361 vm_object_clear_flag(object, OBJ_PIPWNT); 362 wakeup(object); 363 } 364} 365 366void 367vm_object_pip_wait(vm_object_t object, char *waitid) 368{ 369 370 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 371 while (object->paging_in_progress) { 372 object->flags |= OBJ_PIPWNT; 373 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 374 } 375} 376 377/* 378 * vm_object_allocate: 379 * 380 * Returns a new object with the given size. 381 */ 382vm_object_t 383vm_object_allocate(objtype_t type, vm_pindex_t size) 384{ 385 vm_object_t object; 386 387 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 388 _vm_object_allocate(type, size, object); 389 return (object); 390} 391 392 393/* 394 * vm_object_reference: 395 * 396 * Gets another reference to the given object. Note: OBJ_DEAD 397 * objects can be referenced during final cleaning. 398 */ 399void 400vm_object_reference(vm_object_t object) 401{ 402 if (object == NULL) 403 return; 404 VM_OBJECT_LOCK(object); 405 vm_object_reference_locked(object); 406 VM_OBJECT_UNLOCK(object); 407} 408 409/* 410 * vm_object_reference_locked: 411 * 412 * Gets another reference to the given object. 413 * 414 * The object must be locked. 415 */ 416void 417vm_object_reference_locked(vm_object_t object) 418{ 419 struct vnode *vp; 420 421 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 422 object->ref_count++; 423 if (object->type == OBJT_VNODE) { 424 vp = object->handle; 425 vref(vp); 426 } 427} 428 429/* 430 * Handle deallocating an object of type OBJT_VNODE. 431 */ 432static void 433vm_object_vndeallocate(vm_object_t object) 434{ 435 struct vnode *vp = (struct vnode *) object->handle; 436 437 VFS_ASSERT_GIANT(vp->v_mount); 438 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 439 KASSERT(object->type == OBJT_VNODE, 440 ("vm_object_vndeallocate: not a vnode object")); 441 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 442#ifdef INVARIANTS 443 if (object->ref_count == 0) { 444 vprint("vm_object_vndeallocate", vp); 445 panic("vm_object_vndeallocate: bad object reference count"); 446 } 447#endif 448 449 object->ref_count--; 450 if (object->ref_count == 0) { 451 mp_fixme("Unlocked vflag access."); 452 vp->v_vflag &= ~VV_TEXT; 453 } 454 VM_OBJECT_UNLOCK(object); 455 /* 456 * vrele may need a vop lock 457 */ 458 vrele(vp); 459} 460 461/* 462 * vm_object_deallocate: 463 * 464 * Release a reference to the specified object, 465 * gained either through a vm_object_allocate 466 * or a vm_object_reference call. When all references 467 * are gone, storage associated with this object 468 * may be relinquished. 469 * 470 * No object may be locked. 471 */ 472void 473vm_object_deallocate(vm_object_t object) 474{ 475 vm_object_t temp; 476 477 while (object != NULL) { 478 int vfslocked; 479 480 vfslocked = 0; 481 restart: 482 VM_OBJECT_LOCK(object); 483 if (object->type == OBJT_VNODE) { 484 struct vnode *vp = (struct vnode *) object->handle; 485 486 /* 487 * Conditionally acquire Giant for a vnode-backed 488 * object. We have to be careful since the type of 489 * a vnode object can change while the object is 490 * unlocked. 491 */ 492 if (VFS_NEEDSGIANT(vp->v_mount) && !vfslocked) { 493 vfslocked = 1; 494 if (!mtx_trylock(&Giant)) { 495 VM_OBJECT_UNLOCK(object); 496 mtx_lock(&Giant); 497 goto restart; 498 } 499 } 500 vm_object_vndeallocate(object); 501 VFS_UNLOCK_GIANT(vfslocked); 502 return; 503 } else 504 /* 505 * This is to handle the case that the object 506 * changed type while we dropped its lock to 507 * obtain Giant. 508 */ 509 VFS_UNLOCK_GIANT(vfslocked); 510 511 KASSERT(object->ref_count != 0, 512 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 513 514 /* 515 * If the reference count goes to 0 we start calling 516 * vm_object_terminate() on the object chain. 517 * A ref count of 1 may be a special case depending on the 518 * shadow count being 0 or 1. 519 */ 520 object->ref_count--; 521 if (object->ref_count > 1) { 522 VM_OBJECT_UNLOCK(object); 523 return; 524 } else if (object->ref_count == 1) { 525 if (object->shadow_count == 0 && 526 object->handle == NULL && 527 (object->type == OBJT_DEFAULT || 528 object->type == OBJT_SWAP)) { 529 vm_object_set_flag(object, OBJ_ONEMAPPING); 530 } else if ((object->shadow_count == 1) && 531 (object->handle == NULL) && 532 (object->type == OBJT_DEFAULT || 533 object->type == OBJT_SWAP)) { 534 vm_object_t robject; 535 536 robject = LIST_FIRST(&object->shadow_head); 537 KASSERT(robject != NULL, 538 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 539 object->ref_count, 540 object->shadow_count)); 541 if (!VM_OBJECT_TRYLOCK(robject)) { 542 /* 543 * Avoid a potential deadlock. 544 */ 545 object->ref_count++; 546 VM_OBJECT_UNLOCK(object); 547 /* 548 * More likely than not the thread 549 * holding robject's lock has lower 550 * priority than the current thread. 551 * Let the lower priority thread run. 552 */ 553 pause("vmo_de", 1); 554 continue; 555 } 556 /* 557 * Collapse object into its shadow unless its 558 * shadow is dead. In that case, object will 559 * be deallocated by the thread that is 560 * deallocating its shadow. 561 */ 562 if ((robject->flags & OBJ_DEAD) == 0 && 563 (robject->handle == NULL) && 564 (robject->type == OBJT_DEFAULT || 565 robject->type == OBJT_SWAP)) { 566 567 robject->ref_count++; 568retry: 569 if (robject->paging_in_progress) { 570 VM_OBJECT_UNLOCK(object); 571 vm_object_pip_wait(robject, 572 "objde1"); 573 temp = robject->backing_object; 574 if (object == temp) { 575 VM_OBJECT_LOCK(object); 576 goto retry; 577 } 578 } else if (object->paging_in_progress) { 579 VM_OBJECT_UNLOCK(robject); 580 object->flags |= OBJ_PIPWNT; 581 msleep(object, 582 VM_OBJECT_MTX(object), 583 PDROP | PVM, "objde2", 0); 584 VM_OBJECT_LOCK(robject); 585 temp = robject->backing_object; 586 if (object == temp) { 587 VM_OBJECT_LOCK(object); 588 goto retry; 589 } 590 } else 591 VM_OBJECT_UNLOCK(object); 592 593 if (robject->ref_count == 1) { 594 robject->ref_count--; 595 object = robject; 596 goto doterm; 597 } 598 object = robject; 599 vm_object_collapse(object); 600 VM_OBJECT_UNLOCK(object); 601 continue; 602 } 603 VM_OBJECT_UNLOCK(robject); 604 } 605 VM_OBJECT_UNLOCK(object); 606 return; 607 } 608doterm: 609 temp = object->backing_object; 610 if (temp != NULL) { 611 VM_OBJECT_LOCK(temp); 612 LIST_REMOVE(object, shadow_list); 613 temp->shadow_count--; 614 temp->generation++; 615 VM_OBJECT_UNLOCK(temp); 616 object->backing_object = NULL; 617 } 618 /* 619 * Don't double-terminate, we could be in a termination 620 * recursion due to the terminate having to sync data 621 * to disk. 622 */ 623 if ((object->flags & OBJ_DEAD) == 0) 624 vm_object_terminate(object); 625 else 626 VM_OBJECT_UNLOCK(object); 627 object = temp; 628 } 629} 630 631/* 632 * vm_object_destroy removes the object from the global object list 633 * and frees the space for the object. 634 */ 635void 636vm_object_destroy(vm_object_t object) 637{ 638 639 /* 640 * Remove the object from the global object list. 641 */ 642 mtx_lock(&vm_object_list_mtx); 643 TAILQ_REMOVE(&vm_object_list, object, object_list); 644 mtx_unlock(&vm_object_list_mtx); 645 646 /* 647 * Release the allocation charge. 648 */ 649 if (object->uip != NULL) { 650 KASSERT(object->type == OBJT_DEFAULT || 651 object->type == OBJT_SWAP, 652 ("vm_object_terminate: non-swap obj %p has uip", 653 object)); 654 swap_release_by_uid(object->charge, object->uip); 655 object->charge = 0; 656 uifree(object->uip); 657 object->uip = NULL; 658 } 659 660 /* 661 * Free the space for the object. 662 */ 663 uma_zfree(obj_zone, object); 664} 665 666/* 667 * vm_object_terminate actually destroys the specified object, freeing 668 * up all previously used resources. 669 * 670 * The object must be locked. 671 * This routine may block. 672 */ 673void 674vm_object_terminate(vm_object_t object) 675{ 676 vm_page_t p; 677 678 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 679 680 /* 681 * Make sure no one uses us. 682 */ 683 vm_object_set_flag(object, OBJ_DEAD); 684 685 /* 686 * wait for the pageout daemon to be done with the object 687 */ 688 vm_object_pip_wait(object, "objtrm"); 689 690 KASSERT(!object->paging_in_progress, 691 ("vm_object_terminate: pageout in progress")); 692 693 /* 694 * Clean and free the pages, as appropriate. All references to the 695 * object are gone, so we don't need to lock it. 696 */ 697 if (object->type == OBJT_VNODE) { 698 struct vnode *vp = (struct vnode *)object->handle; 699 700 /* 701 * Clean pages and flush buffers. 702 */ 703 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 704 VM_OBJECT_UNLOCK(object); 705 706 vinvalbuf(vp, V_SAVE, 0, 0); 707 708 VM_OBJECT_LOCK(object); 709 } 710 711 KASSERT(object->ref_count == 0, 712 ("vm_object_terminate: object with references, ref_count=%d", 713 object->ref_count)); 714 715 /* 716 * Now free any remaining pages. For internal objects, this also 717 * removes them from paging queues. Don't free wired pages, just 718 * remove them from the object. 719 */ 720 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 721 KASSERT(!p->busy && (p->oflags & VPO_BUSY) == 0, 722 ("vm_object_terminate: freeing busy page %p " 723 "p->busy = %d, p->oflags %x\n", p, p->busy, p->oflags)); 724 vm_page_lock(p); 725 if (p->wire_count == 0) { 726 vm_page_free(p); 727 PCPU_INC(cnt.v_pfree); 728 } else 729 vm_page_remove(p); 730 vm_page_unlock(p); 731 } 732 733#if VM_NRESERVLEVEL > 0 734 if (__predict_false(!LIST_EMPTY(&object->rvq))) 735 vm_reserv_break_all(object); 736#endif 737 if (__predict_false(object->cache != NULL)) 738 vm_page_cache_free(object, 0, 0); 739 740 /* 741 * Let the pager know object is dead. 742 */ 743 vm_pager_deallocate(object); 744 VM_OBJECT_UNLOCK(object); 745 746 vm_object_destroy(object); 747} 748 749/* 750 * vm_object_page_clean 751 * 752 * Clean all dirty pages in the specified range of object. Leaves page 753 * on whatever queue it is currently on. If NOSYNC is set then do not 754 * write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC), 755 * leaving the object dirty. 756 * 757 * When stuffing pages asynchronously, allow clustering. XXX we need a 758 * synchronous clustering mode implementation. 759 * 760 * Odd semantics: if start == end, we clean everything. 761 * 762 * The object must be locked. 763 */ 764void 765vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 766{ 767 vm_page_t p, np; 768 vm_pindex_t tstart, tend; 769 vm_pindex_t pi; 770 int clearobjflags; 771 int pagerflags; 772 int curgeneration; 773 774 mtx_assert(&vm_page_queue_mtx, MA_NOTOWNED); 775 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 776 if ((object->flags & OBJ_MIGHTBEDIRTY) == 0) 777 return; 778 KASSERT(object->type == OBJT_VNODE, ("Not a vnode object")); 779 780 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 781 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 782 783 vm_object_set_flag(object, OBJ_CLEANING); 784 785 tstart = start; 786 if (end == 0) { 787 tend = object->size; 788 } else { 789 tend = end; 790 } 791 792 /* 793 * If the caller is smart and only msync()s a range he knows is 794 * dirty, we may be able to avoid an object scan. This results in 795 * a phenominal improvement in performance. We cannot do this 796 * as a matter of course because the object may be huge - e.g. 797 * the size might be in the gigabytes or terrabytes. 798 */ 799 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 800 vm_pindex_t tscan; 801 int scanlimit; 802 int scanreset; 803 804 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 805 if (scanreset < 16) 806 scanreset = 16; 807 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 808 809 scanlimit = scanreset; 810 tscan = tstart; 811 while (tscan < tend) { 812 curgeneration = object->generation; 813 p = vm_page_lookup(object, tscan); 814 if (p == NULL || p->valid == 0) { 815 if (--scanlimit == 0) 816 break; 817 ++tscan; 818 continue; 819 } 820 vm_page_test_dirty(p); 821 if (p->dirty == 0) { 822 if (--scanlimit == 0) 823 break; 824 ++tscan; 825 continue; 826 } 827 /* 828 * If we have been asked to skip nosync pages and 829 * this is a nosync page, we can't continue. 830 */ 831 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 832 if (--scanlimit == 0) 833 break; 834 ++tscan; 835 continue; 836 } 837 scanlimit = scanreset; 838 839 /* 840 * This returns 0 if it was unable to busy the first 841 * page (i.e. had to sleep). 842 */ 843 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 844 845 } 846 847 /* 848 * If everything was dirty and we flushed it successfully, 849 * and the requested range is not the entire object, we 850 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 851 * return immediately. 852 */ 853 if (tscan >= tend && (tstart || tend < object->size)) { 854 vm_object_clear_flag(object, OBJ_CLEANING); 855 return; 856 } 857 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 858 } 859 860 /* 861 * Generally set CLEANCHK interlock and make the page read-only so 862 * we can then clear the object flags. 863 * 864 * However, if this is a nosync mmap then the object is likely to 865 * stay dirty so do not mess with the page and do not clear the 866 * object flags. 867 */ 868 clearobjflags = 1; 869 TAILQ_FOREACH(p, &object->memq, listq) { 870 p->oflags |= VPO_CLEANCHK; 871 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) 872 clearobjflags = 0; 873 else 874 pmap_remove_write(p); 875 } 876 877 if (clearobjflags && (tstart == 0) && (tend == object->size)) 878 vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY); 879 880rescan: 881 curgeneration = object->generation; 882 883 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 884 int n; 885 886 np = TAILQ_NEXT(p, listq); 887 888again: 889 pi = p->pindex; 890 if ((p->oflags & VPO_CLEANCHK) == 0 || 891 (pi < tstart) || (pi >= tend) || 892 p->valid == 0) { 893 p->oflags &= ~VPO_CLEANCHK; 894 continue; 895 } 896 897 vm_page_test_dirty(p); 898 if (p->dirty == 0) { 899 p->oflags &= ~VPO_CLEANCHK; 900 continue; 901 } 902 /* 903 * If we have been asked to skip nosync pages and this is a 904 * nosync page, skip it. Note that the object flags were 905 * not cleared in this case so we do not have to set them. 906 */ 907 if ((flags & OBJPC_NOSYNC) && (p->oflags & VPO_NOSYNC)) { 908 p->oflags &= ~VPO_CLEANCHK; 909 continue; 910 } 911 912 n = vm_object_page_collect_flush(object, p, 913 curgeneration, pagerflags); 914 if (n == 0) 915 goto rescan; 916 917 if (object->generation != curgeneration) 918 goto rescan; 919 920 /* 921 * Try to optimize the next page. If we can't we pick up 922 * our (random) scan where we left off. 923 */ 924 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) 925 if ((p = vm_page_lookup(object, pi + n)) != NULL) 926 goto again; 927 } 928#if 0 929 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 930#endif 931 932 vm_object_clear_flag(object, OBJ_CLEANING); 933 return; 934} 935 936static int 937vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 938{ 939 int runlen; 940 int maxf; 941 int chkb; 942 int maxb; 943 int i; 944 vm_pindex_t pi; 945 vm_page_t maf[vm_pageout_page_count]; 946 vm_page_t mab[vm_pageout_page_count]; 947 vm_page_t ma[vm_pageout_page_count]; 948 949 mtx_assert(&vm_page_queue_mtx, MA_NOTOWNED); 950 vm_page_lock_assert(p, MA_NOTOWNED); 951 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 952 pi = p->pindex; 953 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 954 if (object->generation != curgeneration) { 955 return(0); 956 } 957 } 958 maxf = 0; 959 for(i = 1; i < vm_pageout_page_count; i++) { 960 vm_page_t tp; 961 962 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 963 if ((tp->oflags & VPO_BUSY) || 964 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 965 (tp->oflags & VPO_CLEANCHK) == 0) || 966 (tp->busy != 0)) 967 break; 968 vm_page_test_dirty(tp); 969 if (tp->dirty == 0) { 970 tp->oflags &= ~VPO_CLEANCHK; 971 break; 972 } 973 maf[ i - 1 ] = tp; 974 maxf++; 975 continue; 976 } 977 break; 978 } 979 980 maxb = 0; 981 chkb = vm_pageout_page_count - maxf; 982 if (chkb) { 983 for(i = 1; i < chkb;i++) { 984 vm_page_t tp; 985 986 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 987 if ((tp->oflags & VPO_BUSY) || 988 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 989 (tp->oflags & VPO_CLEANCHK) == 0) || 990 (tp->busy != 0)) 991 break; 992 vm_page_test_dirty(tp); 993 if (tp->dirty == 0) { 994 tp->oflags &= ~VPO_CLEANCHK; 995 break; 996 } 997 mab[ i - 1 ] = tp; 998 maxb++; 999 continue; 1000 } 1001 break; 1002 } 1003 } 1004 1005 for(i = 0; i < maxb; i++) { 1006 int index = (maxb - i) - 1; 1007 ma[index] = mab[i]; 1008 ma[index]->oflags &= ~VPO_CLEANCHK; 1009 } 1010 p->oflags &= ~VPO_CLEANCHK; 1011 ma[maxb] = p; 1012 for(i = 0; i < maxf; i++) { 1013 int index = (maxb + i) + 1; 1014 ma[index] = maf[i]; 1015 ma[index]->oflags &= ~VPO_CLEANCHK; 1016 } 1017 runlen = maxb + maxf + 1; 1018 1019 vm_pageout_flush(ma, runlen, pagerflags); 1020 for (i = 0; i < runlen; i++) { 1021 if (ma[i]->dirty) { 1022 pmap_remove_write(ma[i]); 1023 ma[i]->oflags |= VPO_CLEANCHK; 1024 1025 /* 1026 * maxf will end up being the actual number of pages 1027 * we wrote out contiguously, non-inclusive of the 1028 * first page. We do not count look-behind pages. 1029 */ 1030 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 1031 maxf = i - maxb - 1; 1032 } 1033 } 1034 return(maxf + 1); 1035} 1036 1037/* 1038 * Note that there is absolutely no sense in writing out 1039 * anonymous objects, so we track down the vnode object 1040 * to write out. 1041 * We invalidate (remove) all pages from the address space 1042 * for semantic correctness. 1043 * 1044 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 1045 * may start out with a NULL object. 1046 */ 1047void 1048vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 1049 boolean_t syncio, boolean_t invalidate) 1050{ 1051 vm_object_t backing_object; 1052 struct vnode *vp; 1053 struct mount *mp; 1054 int flags; 1055 1056 if (object == NULL) 1057 return; 1058 VM_OBJECT_LOCK(object); 1059 while ((backing_object = object->backing_object) != NULL) { 1060 VM_OBJECT_LOCK(backing_object); 1061 offset += object->backing_object_offset; 1062 VM_OBJECT_UNLOCK(object); 1063 object = backing_object; 1064 if (object->size < OFF_TO_IDX(offset + size)) 1065 size = IDX_TO_OFF(object->size) - offset; 1066 } 1067 /* 1068 * Flush pages if writing is allowed, invalidate them 1069 * if invalidation requested. Pages undergoing I/O 1070 * will be ignored by vm_object_page_remove(). 1071 * 1072 * We cannot lock the vnode and then wait for paging 1073 * to complete without deadlocking against vm_fault. 1074 * Instead we simply call vm_object_page_remove() and 1075 * allow it to block internally on a page-by-page 1076 * basis when it encounters pages undergoing async 1077 * I/O. 1078 */ 1079 if (object->type == OBJT_VNODE && 1080 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1081 int vfslocked; 1082 vp = object->handle; 1083 VM_OBJECT_UNLOCK(object); 1084 (void) vn_start_write(vp, &mp, V_WAIT); 1085 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1086 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 1087 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1088 flags |= invalidate ? OBJPC_INVAL : 0; 1089 VM_OBJECT_LOCK(object); 1090 vm_object_page_clean(object, 1091 OFF_TO_IDX(offset), 1092 OFF_TO_IDX(offset + size + PAGE_MASK), 1093 flags); 1094 VM_OBJECT_UNLOCK(object); 1095 VOP_UNLOCK(vp, 0); 1096 VFS_UNLOCK_GIANT(vfslocked); 1097 vn_finished_write(mp); 1098 VM_OBJECT_LOCK(object); 1099 } 1100 if ((object->type == OBJT_VNODE || 1101 object->type == OBJT_DEVICE) && invalidate) { 1102 boolean_t purge; 1103 purge = old_msync || (object->type == OBJT_DEVICE); 1104 vm_object_page_remove(object, 1105 OFF_TO_IDX(offset), 1106 OFF_TO_IDX(offset + size + PAGE_MASK), 1107 purge ? FALSE : TRUE); 1108 } 1109 VM_OBJECT_UNLOCK(object); 1110} 1111 1112/* 1113 * vm_object_madvise: 1114 * 1115 * Implements the madvise function at the object/page level. 1116 * 1117 * MADV_WILLNEED (any object) 1118 * 1119 * Activate the specified pages if they are resident. 1120 * 1121 * MADV_DONTNEED (any object) 1122 * 1123 * Deactivate the specified pages if they are resident. 1124 * 1125 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1126 * OBJ_ONEMAPPING only) 1127 * 1128 * Deactivate and clean the specified pages if they are 1129 * resident. This permits the process to reuse the pages 1130 * without faulting or the kernel to reclaim the pages 1131 * without I/O. 1132 */ 1133void 1134vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1135{ 1136 vm_pindex_t end, tpindex; 1137 vm_object_t backing_object, tobject; 1138 vm_page_t m; 1139 1140 if (object == NULL) 1141 return; 1142 VM_OBJECT_LOCK(object); 1143 end = pindex + count; 1144 /* 1145 * Locate and adjust resident pages 1146 */ 1147 for (; pindex < end; pindex += 1) { 1148relookup: 1149 tobject = object; 1150 tpindex = pindex; 1151shadowlookup: 1152 /* 1153 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1154 * and those pages must be OBJ_ONEMAPPING. 1155 */ 1156 if (advise == MADV_FREE) { 1157 if ((tobject->type != OBJT_DEFAULT && 1158 tobject->type != OBJT_SWAP) || 1159 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1160 goto unlock_tobject; 1161 } 1162 } else if (tobject->type == OBJT_PHYS) 1163 goto unlock_tobject; 1164 m = vm_page_lookup(tobject, tpindex); 1165 if (m == NULL && advise == MADV_WILLNEED) { 1166 /* 1167 * If the page is cached, reactivate it. 1168 */ 1169 m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED | 1170 VM_ALLOC_NOBUSY); 1171 } 1172 if (m == NULL) { 1173 /* 1174 * There may be swap even if there is no backing page 1175 */ 1176 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1177 swap_pager_freespace(tobject, tpindex, 1); 1178 /* 1179 * next object 1180 */ 1181 backing_object = tobject->backing_object; 1182 if (backing_object == NULL) 1183 goto unlock_tobject; 1184 VM_OBJECT_LOCK(backing_object); 1185 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1186 if (tobject != object) 1187 VM_OBJECT_UNLOCK(tobject); 1188 tobject = backing_object; 1189 goto shadowlookup; 1190 } else if (m->valid != VM_PAGE_BITS_ALL) 1191 goto unlock_tobject; 1192 /* 1193 * If the page is not in a normal state, skip it. 1194 */ 1195 vm_page_lock(m); 1196 if (m->hold_count != 0 || m->wire_count != 0) { 1197 vm_page_unlock(m); 1198 goto unlock_tobject; 1199 } 1200 KASSERT((m->flags & (PG_FICTITIOUS | PG_UNMANAGED)) == 0, 1201 ("vm_object_madvise: page %p is not managed", m)); 1202 if ((m->oflags & VPO_BUSY) || m->busy) { 1203 if (advise == MADV_WILLNEED) { 1204 /* 1205 * Reference the page before unlocking and 1206 * sleeping so that the page daemon is less 1207 * likely to reclaim it. 1208 */ 1209 vm_page_lock_queues(); 1210 vm_page_flag_set(m, PG_REFERENCED); 1211 vm_page_unlock_queues(); 1212 } 1213 vm_page_unlock(m); 1214 if (object != tobject) 1215 VM_OBJECT_UNLOCK(object); 1216 m->oflags |= VPO_WANTED; 1217 msleep(m, VM_OBJECT_MTX(tobject), PDROP | PVM, "madvpo", 1218 0); 1219 VM_OBJECT_LOCK(object); 1220 goto relookup; 1221 } 1222 if (advise == MADV_WILLNEED) { 1223 vm_page_activate(m); 1224 } else if (advise == MADV_DONTNEED) { 1225 vm_page_dontneed(m); 1226 } else if (advise == MADV_FREE) { 1227 /* 1228 * Mark the page clean. This will allow the page 1229 * to be freed up by the system. However, such pages 1230 * are often reused quickly by malloc()/free() 1231 * so we do not do anything that would cause 1232 * a page fault if we can help it. 1233 * 1234 * Specifically, we do not try to actually free 1235 * the page now nor do we try to put it in the 1236 * cache (which would cause a page fault on reuse). 1237 * 1238 * But we do make the page is freeable as we 1239 * can without actually taking the step of unmapping 1240 * it. 1241 */ 1242 pmap_clear_modify(m); 1243 m->dirty = 0; 1244 m->act_count = 0; 1245 vm_page_dontneed(m); 1246 } 1247 vm_page_unlock(m); 1248 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1249 swap_pager_freespace(tobject, tpindex, 1); 1250unlock_tobject: 1251 if (tobject != object) 1252 VM_OBJECT_UNLOCK(tobject); 1253 } 1254 VM_OBJECT_UNLOCK(object); 1255} 1256 1257/* 1258 * vm_object_shadow: 1259 * 1260 * Create a new object which is backed by the 1261 * specified existing object range. The source 1262 * object reference is deallocated. 1263 * 1264 * The new object and offset into that object 1265 * are returned in the source parameters. 1266 */ 1267void 1268vm_object_shadow( 1269 vm_object_t *object, /* IN/OUT */ 1270 vm_ooffset_t *offset, /* IN/OUT */ 1271 vm_size_t length) 1272{ 1273 vm_object_t source; 1274 vm_object_t result; 1275 1276 source = *object; 1277 1278 /* 1279 * Don't create the new object if the old object isn't shared. 1280 */ 1281 if (source != NULL) { 1282 VM_OBJECT_LOCK(source); 1283 if (source->ref_count == 1 && 1284 source->handle == NULL && 1285 (source->type == OBJT_DEFAULT || 1286 source->type == OBJT_SWAP)) { 1287 VM_OBJECT_UNLOCK(source); 1288 return; 1289 } 1290 VM_OBJECT_UNLOCK(source); 1291 } 1292 1293 /* 1294 * Allocate a new object with the given length. 1295 */ 1296 result = vm_object_allocate(OBJT_DEFAULT, length); 1297 1298 /* 1299 * The new object shadows the source object, adding a reference to it. 1300 * Our caller changes his reference to point to the new object, 1301 * removing a reference to the source object. Net result: no change 1302 * of reference count. 1303 * 1304 * Try to optimize the result object's page color when shadowing 1305 * in order to maintain page coloring consistency in the combined 1306 * shadowed object. 1307 */ 1308 result->backing_object = source; 1309 /* 1310 * Store the offset into the source object, and fix up the offset into 1311 * the new object. 1312 */ 1313 result->backing_object_offset = *offset; 1314 if (source != NULL) { 1315 VM_OBJECT_LOCK(source); 1316 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1317 source->shadow_count++; 1318 source->generation++; 1319#if VM_NRESERVLEVEL > 0 1320 result->flags |= source->flags & OBJ_COLORED; 1321 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) & 1322 ((1 << (VM_NFREEORDER - 1)) - 1); 1323#endif 1324 VM_OBJECT_UNLOCK(source); 1325 } 1326 1327 1328 /* 1329 * Return the new things 1330 */ 1331 *offset = 0; 1332 *object = result; 1333} 1334 1335/* 1336 * vm_object_split: 1337 * 1338 * Split the pages in a map entry into a new object. This affords 1339 * easier removal of unused pages, and keeps object inheritance from 1340 * being a negative impact on memory usage. 1341 */ 1342void 1343vm_object_split(vm_map_entry_t entry) 1344{ 1345 vm_page_t m, m_next; 1346 vm_object_t orig_object, new_object, source; 1347 vm_pindex_t idx, offidxstart; 1348 vm_size_t size; 1349 1350 orig_object = entry->object.vm_object; 1351 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1352 return; 1353 if (orig_object->ref_count <= 1) 1354 return; 1355 VM_OBJECT_UNLOCK(orig_object); 1356 1357 offidxstart = OFF_TO_IDX(entry->offset); 1358 size = atop(entry->end - entry->start); 1359 1360 /* 1361 * If swap_pager_copy() is later called, it will convert new_object 1362 * into a swap object. 1363 */ 1364 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1365 1366 /* 1367 * At this point, the new object is still private, so the order in 1368 * which the original and new objects are locked does not matter. 1369 */ 1370 VM_OBJECT_LOCK(new_object); 1371 VM_OBJECT_LOCK(orig_object); 1372 source = orig_object->backing_object; 1373 if (source != NULL) { 1374 VM_OBJECT_LOCK(source); 1375 if ((source->flags & OBJ_DEAD) != 0) { 1376 VM_OBJECT_UNLOCK(source); 1377 VM_OBJECT_UNLOCK(orig_object); 1378 VM_OBJECT_UNLOCK(new_object); 1379 vm_object_deallocate(new_object); 1380 VM_OBJECT_LOCK(orig_object); 1381 return; 1382 } 1383 LIST_INSERT_HEAD(&source->shadow_head, 1384 new_object, shadow_list); 1385 source->shadow_count++; 1386 source->generation++; 1387 vm_object_reference_locked(source); /* for new_object */ 1388 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1389 VM_OBJECT_UNLOCK(source); 1390 new_object->backing_object_offset = 1391 orig_object->backing_object_offset + entry->offset; 1392 new_object->backing_object = source; 1393 } 1394 if (orig_object->uip != NULL) { 1395 new_object->uip = orig_object->uip; 1396 uihold(orig_object->uip); 1397 new_object->charge = ptoa(size); 1398 KASSERT(orig_object->charge >= ptoa(size), 1399 ("orig_object->charge < 0")); 1400 orig_object->charge -= ptoa(size); 1401 } 1402retry: 1403 m = vm_page_find_least(orig_object, offidxstart); 1404 for (; m != NULL && (idx = m->pindex - offidxstart) < size; 1405 m = m_next) { 1406 m_next = TAILQ_NEXT(m, listq); 1407 1408 /* 1409 * We must wait for pending I/O to complete before we can 1410 * rename the page. 1411 * 1412 * We do not have to VM_PROT_NONE the page as mappings should 1413 * not be changed by this operation. 1414 */ 1415 if ((m->oflags & VPO_BUSY) || m->busy) { 1416 VM_OBJECT_UNLOCK(new_object); 1417 m->oflags |= VPO_WANTED; 1418 msleep(m, VM_OBJECT_MTX(orig_object), PVM, "spltwt", 0); 1419 VM_OBJECT_LOCK(new_object); 1420 goto retry; 1421 } 1422 vm_page_lock(m); 1423 vm_page_rename(m, new_object, idx); 1424 vm_page_unlock(m); 1425 /* page automatically made dirty by rename and cache handled */ 1426 vm_page_busy(m); 1427 } 1428 if (orig_object->type == OBJT_SWAP) { 1429 /* 1430 * swap_pager_copy() can sleep, in which case the orig_object's 1431 * and new_object's locks are released and reacquired. 1432 */ 1433 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1434 1435 /* 1436 * Transfer any cached pages from orig_object to new_object. 1437 */ 1438 if (__predict_false(orig_object->cache != NULL)) 1439 vm_page_cache_transfer(orig_object, offidxstart, 1440 new_object); 1441 } 1442 VM_OBJECT_UNLOCK(orig_object); 1443 TAILQ_FOREACH(m, &new_object->memq, listq) 1444 vm_page_wakeup(m); 1445 VM_OBJECT_UNLOCK(new_object); 1446 entry->object.vm_object = new_object; 1447 entry->offset = 0LL; 1448 vm_object_deallocate(orig_object); 1449 VM_OBJECT_LOCK(new_object); 1450} 1451 1452#define OBSC_TEST_ALL_SHADOWED 0x0001 1453#define OBSC_COLLAPSE_NOWAIT 0x0002 1454#define OBSC_COLLAPSE_WAIT 0x0004 1455 1456static int 1457vm_object_backing_scan(vm_object_t object, int op) 1458{ 1459 int r = 1; 1460 vm_page_t p; 1461 vm_object_t backing_object; 1462 vm_pindex_t backing_offset_index; 1463 1464 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1465 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1466 1467 backing_object = object->backing_object; 1468 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1469 1470 /* 1471 * Initial conditions 1472 */ 1473 if (op & OBSC_TEST_ALL_SHADOWED) { 1474 /* 1475 * We do not want to have to test for the existence of cache 1476 * or swap pages in the backing object. XXX but with the 1477 * new swapper this would be pretty easy to do. 1478 * 1479 * XXX what about anonymous MAP_SHARED memory that hasn't 1480 * been ZFOD faulted yet? If we do not test for this, the 1481 * shadow test may succeed! XXX 1482 */ 1483 if (backing_object->type != OBJT_DEFAULT) { 1484 return (0); 1485 } 1486 } 1487 if (op & OBSC_COLLAPSE_WAIT) { 1488 vm_object_set_flag(backing_object, OBJ_DEAD); 1489 } 1490 1491 /* 1492 * Our scan 1493 */ 1494 p = TAILQ_FIRST(&backing_object->memq); 1495 while (p) { 1496 vm_page_t next = TAILQ_NEXT(p, listq); 1497 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1498 1499 if (op & OBSC_TEST_ALL_SHADOWED) { 1500 vm_page_t pp; 1501 1502 /* 1503 * Ignore pages outside the parent object's range 1504 * and outside the parent object's mapping of the 1505 * backing object. 1506 * 1507 * note that we do not busy the backing object's 1508 * page. 1509 */ 1510 if ( 1511 p->pindex < backing_offset_index || 1512 new_pindex >= object->size 1513 ) { 1514 p = next; 1515 continue; 1516 } 1517 1518 /* 1519 * See if the parent has the page or if the parent's 1520 * object pager has the page. If the parent has the 1521 * page but the page is not valid, the parent's 1522 * object pager must have the page. 1523 * 1524 * If this fails, the parent does not completely shadow 1525 * the object and we might as well give up now. 1526 */ 1527 1528 pp = vm_page_lookup(object, new_pindex); 1529 if ( 1530 (pp == NULL || pp->valid == 0) && 1531 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1532 ) { 1533 r = 0; 1534 break; 1535 } 1536 } 1537 1538 /* 1539 * Check for busy page 1540 */ 1541 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1542 vm_page_t pp; 1543 1544 if (op & OBSC_COLLAPSE_NOWAIT) { 1545 if ((p->oflags & VPO_BUSY) || 1546 !p->valid || 1547 p->busy) { 1548 p = next; 1549 continue; 1550 } 1551 } else if (op & OBSC_COLLAPSE_WAIT) { 1552 if ((p->oflags & VPO_BUSY) || p->busy) { 1553 VM_OBJECT_UNLOCK(object); 1554 p->oflags |= VPO_WANTED; 1555 msleep(p, VM_OBJECT_MTX(backing_object), 1556 PDROP | PVM, "vmocol", 0); 1557 VM_OBJECT_LOCK(object); 1558 VM_OBJECT_LOCK(backing_object); 1559 /* 1560 * If we slept, anything could have 1561 * happened. Since the object is 1562 * marked dead, the backing offset 1563 * should not have changed so we 1564 * just restart our scan. 1565 */ 1566 p = TAILQ_FIRST(&backing_object->memq); 1567 continue; 1568 } 1569 } 1570 1571 KASSERT( 1572 p->object == backing_object, 1573 ("vm_object_backing_scan: object mismatch") 1574 ); 1575 1576 /* 1577 * Destroy any associated swap 1578 */ 1579 if (backing_object->type == OBJT_SWAP) { 1580 swap_pager_freespace( 1581 backing_object, 1582 p->pindex, 1583 1 1584 ); 1585 } 1586 1587 if ( 1588 p->pindex < backing_offset_index || 1589 new_pindex >= object->size 1590 ) { 1591 /* 1592 * Page is out of the parent object's range, we 1593 * can simply destroy it. 1594 */ 1595 vm_page_lock(p); 1596 KASSERT(!pmap_page_is_mapped(p), 1597 ("freeing mapped page %p", p)); 1598 if (p->wire_count == 0) 1599 vm_page_free(p); 1600 else 1601 vm_page_remove(p); 1602 vm_page_unlock(p); 1603 p = next; 1604 continue; 1605 } 1606 1607 pp = vm_page_lookup(object, new_pindex); 1608 if ( 1609 pp != NULL || 1610 vm_pager_has_page(object, new_pindex, NULL, NULL) 1611 ) { 1612 /* 1613 * page already exists in parent OR swap exists 1614 * for this location in the parent. Destroy 1615 * the original page from the backing object. 1616 * 1617 * Leave the parent's page alone 1618 */ 1619 vm_page_lock(p); 1620 KASSERT(!pmap_page_is_mapped(p), 1621 ("freeing mapped page %p", p)); 1622 if (p->wire_count == 0) 1623 vm_page_free(p); 1624 else 1625 vm_page_remove(p); 1626 vm_page_unlock(p); 1627 p = next; 1628 continue; 1629 } 1630 1631#if VM_NRESERVLEVEL > 0 1632 /* 1633 * Rename the reservation. 1634 */ 1635 vm_reserv_rename(p, object, backing_object, 1636 backing_offset_index); 1637#endif 1638 1639 /* 1640 * Page does not exist in parent, rename the 1641 * page from the backing object to the main object. 1642 * 1643 * If the page was mapped to a process, it can remain 1644 * mapped through the rename. 1645 */ 1646 vm_page_lock(p); 1647 vm_page_rename(p, object, new_pindex); 1648 vm_page_unlock(p); 1649 /* page automatically made dirty by rename */ 1650 } 1651 p = next; 1652 } 1653 return (r); 1654} 1655 1656 1657/* 1658 * this version of collapse allows the operation to occur earlier and 1659 * when paging_in_progress is true for an object... This is not a complete 1660 * operation, but should plug 99.9% of the rest of the leaks. 1661 */ 1662static void 1663vm_object_qcollapse(vm_object_t object) 1664{ 1665 vm_object_t backing_object = object->backing_object; 1666 1667 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1668 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1669 1670 if (backing_object->ref_count != 1) 1671 return; 1672 1673 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1674} 1675 1676/* 1677 * vm_object_collapse: 1678 * 1679 * Collapse an object with the object backing it. 1680 * Pages in the backing object are moved into the 1681 * parent, and the backing object is deallocated. 1682 */ 1683void 1684vm_object_collapse(vm_object_t object) 1685{ 1686 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1687 1688 while (TRUE) { 1689 vm_object_t backing_object; 1690 1691 /* 1692 * Verify that the conditions are right for collapse: 1693 * 1694 * The object exists and the backing object exists. 1695 */ 1696 if ((backing_object = object->backing_object) == NULL) 1697 break; 1698 1699 /* 1700 * we check the backing object first, because it is most likely 1701 * not collapsable. 1702 */ 1703 VM_OBJECT_LOCK(backing_object); 1704 if (backing_object->handle != NULL || 1705 (backing_object->type != OBJT_DEFAULT && 1706 backing_object->type != OBJT_SWAP) || 1707 (backing_object->flags & OBJ_DEAD) || 1708 object->handle != NULL || 1709 (object->type != OBJT_DEFAULT && 1710 object->type != OBJT_SWAP) || 1711 (object->flags & OBJ_DEAD)) { 1712 VM_OBJECT_UNLOCK(backing_object); 1713 break; 1714 } 1715 1716 if ( 1717 object->paging_in_progress != 0 || 1718 backing_object->paging_in_progress != 0 1719 ) { 1720 vm_object_qcollapse(object); 1721 VM_OBJECT_UNLOCK(backing_object); 1722 break; 1723 } 1724 /* 1725 * We know that we can either collapse the backing object (if 1726 * the parent is the only reference to it) or (perhaps) have 1727 * the parent bypass the object if the parent happens to shadow 1728 * all the resident pages in the entire backing object. 1729 * 1730 * This is ignoring pager-backed pages such as swap pages. 1731 * vm_object_backing_scan fails the shadowing test in this 1732 * case. 1733 */ 1734 if (backing_object->ref_count == 1) { 1735 /* 1736 * If there is exactly one reference to the backing 1737 * object, we can collapse it into the parent. 1738 */ 1739 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1740 1741#if VM_NRESERVLEVEL > 0 1742 /* 1743 * Break any reservations from backing_object. 1744 */ 1745 if (__predict_false(!LIST_EMPTY(&backing_object->rvq))) 1746 vm_reserv_break_all(backing_object); 1747#endif 1748 1749 /* 1750 * Move the pager from backing_object to object. 1751 */ 1752 if (backing_object->type == OBJT_SWAP) { 1753 /* 1754 * swap_pager_copy() can sleep, in which case 1755 * the backing_object's and object's locks are 1756 * released and reacquired. 1757 */ 1758 swap_pager_copy( 1759 backing_object, 1760 object, 1761 OFF_TO_IDX(object->backing_object_offset), TRUE); 1762 1763 /* 1764 * Free any cached pages from backing_object. 1765 */ 1766 if (__predict_false(backing_object->cache != NULL)) 1767 vm_page_cache_free(backing_object, 0, 0); 1768 } 1769 /* 1770 * Object now shadows whatever backing_object did. 1771 * Note that the reference to 1772 * backing_object->backing_object moves from within 1773 * backing_object to within object. 1774 */ 1775 LIST_REMOVE(object, shadow_list); 1776 backing_object->shadow_count--; 1777 backing_object->generation++; 1778 if (backing_object->backing_object) { 1779 VM_OBJECT_LOCK(backing_object->backing_object); 1780 LIST_REMOVE(backing_object, shadow_list); 1781 LIST_INSERT_HEAD( 1782 &backing_object->backing_object->shadow_head, 1783 object, shadow_list); 1784 /* 1785 * The shadow_count has not changed. 1786 */ 1787 backing_object->backing_object->generation++; 1788 VM_OBJECT_UNLOCK(backing_object->backing_object); 1789 } 1790 object->backing_object = backing_object->backing_object; 1791 object->backing_object_offset += 1792 backing_object->backing_object_offset; 1793 1794 /* 1795 * Discard backing_object. 1796 * 1797 * Since the backing object has no pages, no pager left, 1798 * and no object references within it, all that is 1799 * necessary is to dispose of it. 1800 */ 1801 KASSERT(backing_object->ref_count == 1, ( 1802"backing_object %p was somehow re-referenced during collapse!", 1803 backing_object)); 1804 VM_OBJECT_UNLOCK(backing_object); 1805 vm_object_destroy(backing_object); 1806 1807 object_collapses++; 1808 } else { 1809 vm_object_t new_backing_object; 1810 1811 /* 1812 * If we do not entirely shadow the backing object, 1813 * there is nothing we can do so we give up. 1814 */ 1815 if (object->resident_page_count != object->size && 1816 vm_object_backing_scan(object, 1817 OBSC_TEST_ALL_SHADOWED) == 0) { 1818 VM_OBJECT_UNLOCK(backing_object); 1819 break; 1820 } 1821 1822 /* 1823 * Make the parent shadow the next object in the 1824 * chain. Deallocating backing_object will not remove 1825 * it, since its reference count is at least 2. 1826 */ 1827 LIST_REMOVE(object, shadow_list); 1828 backing_object->shadow_count--; 1829 backing_object->generation++; 1830 1831 new_backing_object = backing_object->backing_object; 1832 if ((object->backing_object = new_backing_object) != NULL) { 1833 VM_OBJECT_LOCK(new_backing_object); 1834 LIST_INSERT_HEAD( 1835 &new_backing_object->shadow_head, 1836 object, 1837 shadow_list 1838 ); 1839 new_backing_object->shadow_count++; 1840 new_backing_object->generation++; 1841 vm_object_reference_locked(new_backing_object); 1842 VM_OBJECT_UNLOCK(new_backing_object); 1843 object->backing_object_offset += 1844 backing_object->backing_object_offset; 1845 } 1846 1847 /* 1848 * Drop the reference count on backing_object. Since 1849 * its ref_count was at least 2, it will not vanish. 1850 */ 1851 backing_object->ref_count--; 1852 VM_OBJECT_UNLOCK(backing_object); 1853 object_bypasses++; 1854 } 1855 1856 /* 1857 * Try again with this object's new backing object. 1858 */ 1859 } 1860} 1861 1862/* 1863 * vm_object_page_remove: 1864 * 1865 * For the given object, either frees or invalidates each of the 1866 * specified pages. In general, a page is freed. However, if a 1867 * page is wired for any reason other than the existence of a 1868 * managed, wired mapping, then it may be invalidated but not 1869 * removed from the object. Pages are specified by the given 1870 * range ["start", "end") and Boolean "clean_only". As a 1871 * special case, if "end" is zero, then the range extends from 1872 * "start" to the end of the object. If "clean_only" is TRUE, 1873 * then only the non-dirty pages within the specified range are 1874 * affected. 1875 * 1876 * In general, this operation should only be performed on objects 1877 * that contain managed pages. There are two exceptions. First, 1878 * it may be performed on the kernel and kmem objects. Second, 1879 * it may be used by msync(..., MS_INVALIDATE) to invalidate 1880 * device-backed pages. In both of these cases, "clean_only" 1881 * must be FALSE. 1882 * 1883 * The object must be locked. 1884 */ 1885void 1886vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1887 boolean_t clean_only) 1888{ 1889 vm_page_t p, next; 1890 int wirings; 1891 1892 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1893 if (object->resident_page_count == 0) 1894 goto skipmemq; 1895 1896 /* 1897 * Since physically-backed objects do not use managed pages, we can't 1898 * remove pages from the object (we must instead remove the page 1899 * references, and then destroy the object). 1900 */ 1901 KASSERT(object->type != OBJT_PHYS || object == kernel_object || 1902 object == kmem_object, 1903 ("attempt to remove pages from a physical object")); 1904 1905 vm_object_pip_add(object, 1); 1906again: 1907 p = vm_page_find_least(object, start); 1908 1909 /* 1910 * Assert: the variable p is either (1) the page with the 1911 * least pindex greater than or equal to the parameter pindex 1912 * or (2) NULL. 1913 */ 1914 for (; 1915 p != NULL && (p->pindex < end || end == 0); 1916 p = next) { 1917 next = TAILQ_NEXT(p, listq); 1918 1919 /* 1920 * If the page is wired for any reason besides the 1921 * existence of managed, wired mappings, then it cannot 1922 * be freed. For example, fictitious pages, which 1923 * represent device memory, are inherently wired and 1924 * cannot be freed. They can, however, be invalidated 1925 * if "clean_only" is FALSE. 1926 */ 1927 vm_page_lock(p); 1928 if ((wirings = p->wire_count) != 0 && 1929 (wirings = pmap_page_wired_mappings(p)) != p->wire_count) { 1930 /* Fictitious pages do not have managed mappings. */ 1931 if ((p->flags & PG_FICTITIOUS) == 0) 1932 pmap_remove_all(p); 1933 /* Account for removal of managed, wired mappings. */ 1934 p->wire_count -= wirings; 1935 if (!clean_only) { 1936 p->valid = 0; 1937 vm_page_undirty(p); 1938 } 1939 vm_page_unlock(p); 1940 continue; 1941 } 1942 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1943 goto again; 1944 KASSERT((p->flags & PG_FICTITIOUS) == 0, 1945 ("vm_object_page_remove: page %p is fictitious", p)); 1946 if (clean_only && p->valid) { 1947 pmap_remove_write(p); 1948 if (p->dirty) { 1949 vm_page_unlock(p); 1950 continue; 1951 } 1952 } 1953 pmap_remove_all(p); 1954 /* Account for removal of managed, wired mappings. */ 1955 if (wirings != 0) 1956 p->wire_count -= wirings; 1957 vm_page_free(p); 1958 vm_page_unlock(p); 1959 } 1960 vm_object_pip_wakeup(object); 1961skipmemq: 1962 if (__predict_false(object->cache != NULL)) 1963 vm_page_cache_free(object, start, end); 1964} 1965 1966/* 1967 * Populate the specified range of the object with valid pages. Returns 1968 * TRUE if the range is successfully populated and FALSE otherwise. 1969 * 1970 * Note: This function should be optimized to pass a larger array of 1971 * pages to vm_pager_get_pages() before it is applied to a non- 1972 * OBJT_DEVICE object. 1973 * 1974 * The object must be locked. 1975 */ 1976boolean_t 1977vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end) 1978{ 1979 vm_page_t m, ma[1]; 1980 vm_pindex_t pindex; 1981 int rv; 1982 1983 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1984 for (pindex = start; pindex < end; pindex++) { 1985 m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL | 1986 VM_ALLOC_RETRY); 1987 if (m->valid != VM_PAGE_BITS_ALL) { 1988 ma[0] = m; 1989 rv = vm_pager_get_pages(object, ma, 1, 0); 1990 m = vm_page_lookup(object, pindex); 1991 if (m == NULL) 1992 break; 1993 if (rv != VM_PAGER_OK) { 1994 vm_page_lock(m); 1995 vm_page_free(m); 1996 vm_page_unlock(m); 1997 break; 1998 } 1999 } 2000 /* 2001 * Keep "m" busy because a subsequent iteration may unlock 2002 * the object. 2003 */ 2004 } 2005 if (pindex > start) { 2006 m = vm_page_lookup(object, start); 2007 while (m != NULL && m->pindex < pindex) { 2008 vm_page_wakeup(m); 2009 m = TAILQ_NEXT(m, listq); 2010 } 2011 } 2012 return (pindex == end); 2013} 2014 2015/* 2016 * Routine: vm_object_coalesce 2017 * Function: Coalesces two objects backing up adjoining 2018 * regions of memory into a single object. 2019 * 2020 * returns TRUE if objects were combined. 2021 * 2022 * NOTE: Only works at the moment if the second object is NULL - 2023 * if it's not, which object do we lock first? 2024 * 2025 * Parameters: 2026 * prev_object First object to coalesce 2027 * prev_offset Offset into prev_object 2028 * prev_size Size of reference to prev_object 2029 * next_size Size of reference to the second object 2030 * reserved Indicator that extension region has 2031 * swap accounted for 2032 * 2033 * Conditions: 2034 * The object must *not* be locked. 2035 */ 2036boolean_t 2037vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 2038 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved) 2039{ 2040 vm_pindex_t next_pindex; 2041 2042 if (prev_object == NULL) 2043 return (TRUE); 2044 VM_OBJECT_LOCK(prev_object); 2045 if (prev_object->type != OBJT_DEFAULT && 2046 prev_object->type != OBJT_SWAP) { 2047 VM_OBJECT_UNLOCK(prev_object); 2048 return (FALSE); 2049 } 2050 2051 /* 2052 * Try to collapse the object first 2053 */ 2054 vm_object_collapse(prev_object); 2055 2056 /* 2057 * Can't coalesce if: . more than one reference . paged out . shadows 2058 * another object . has a copy elsewhere (any of which mean that the 2059 * pages not mapped to prev_entry may be in use anyway) 2060 */ 2061 if (prev_object->backing_object != NULL) { 2062 VM_OBJECT_UNLOCK(prev_object); 2063 return (FALSE); 2064 } 2065 2066 prev_size >>= PAGE_SHIFT; 2067 next_size >>= PAGE_SHIFT; 2068 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 2069 2070 if ((prev_object->ref_count > 1) && 2071 (prev_object->size != next_pindex)) { 2072 VM_OBJECT_UNLOCK(prev_object); 2073 return (FALSE); 2074 } 2075 2076 /* 2077 * Account for the charge. 2078 */ 2079 if (prev_object->uip != NULL) { 2080 2081 /* 2082 * If prev_object was charged, then this mapping, 2083 * althought not charged now, may become writable 2084 * later. Non-NULL uip in the object would prevent 2085 * swap reservation during enabling of the write 2086 * access, so reserve swap now. Failed reservation 2087 * cause allocation of the separate object for the map 2088 * entry, and swap reservation for this entry is 2089 * managed in appropriate time. 2090 */ 2091 if (!reserved && !swap_reserve_by_uid(ptoa(next_size), 2092 prev_object->uip)) { 2093 return (FALSE); 2094 } 2095 prev_object->charge += ptoa(next_size); 2096 } 2097 2098 /* 2099 * Remove any pages that may still be in the object from a previous 2100 * deallocation. 2101 */ 2102 if (next_pindex < prev_object->size) { 2103 vm_object_page_remove(prev_object, 2104 next_pindex, 2105 next_pindex + next_size, FALSE); 2106 if (prev_object->type == OBJT_SWAP) 2107 swap_pager_freespace(prev_object, 2108 next_pindex, next_size); 2109#if 0 2110 if (prev_object->uip != NULL) { 2111 KASSERT(prev_object->charge >= 2112 ptoa(prev_object->size - next_pindex), 2113 ("object %p overcharged 1 %jx %jx", prev_object, 2114 (uintmax_t)next_pindex, (uintmax_t)next_size)); 2115 prev_object->charge -= ptoa(prev_object->size - 2116 next_pindex); 2117 } 2118#endif 2119 } 2120 2121 /* 2122 * Extend the object if necessary. 2123 */ 2124 if (next_pindex + next_size > prev_object->size) 2125 prev_object->size = next_pindex + next_size; 2126 2127 VM_OBJECT_UNLOCK(prev_object); 2128 return (TRUE); 2129} 2130 2131void 2132vm_object_set_writeable_dirty(vm_object_t object) 2133{ 2134 2135 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 2136 if (object->type != OBJT_VNODE || 2137 (object->flags & OBJ_MIGHTBEDIRTY) != 0) 2138 return; 2139 vm_object_set_flag(object, OBJ_MIGHTBEDIRTY); 2140} 2141 2142#include "opt_ddb.h" 2143#ifdef DDB 2144#include <sys/kernel.h> 2145 2146#include <sys/cons.h> 2147 2148#include <ddb/ddb.h> 2149 2150static int 2151_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 2152{ 2153 vm_map_t tmpm; 2154 vm_map_entry_t tmpe; 2155 vm_object_t obj; 2156 int entcount; 2157 2158 if (map == 0) 2159 return 0; 2160 2161 if (entry == 0) { 2162 tmpe = map->header.next; 2163 entcount = map->nentries; 2164 while (entcount-- && (tmpe != &map->header)) { 2165 if (_vm_object_in_map(map, object, tmpe)) { 2166 return 1; 2167 } 2168 tmpe = tmpe->next; 2169 } 2170 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 2171 tmpm = entry->object.sub_map; 2172 tmpe = tmpm->header.next; 2173 entcount = tmpm->nentries; 2174 while (entcount-- && tmpe != &tmpm->header) { 2175 if (_vm_object_in_map(tmpm, object, tmpe)) { 2176 return 1; 2177 } 2178 tmpe = tmpe->next; 2179 } 2180 } else if ((obj = entry->object.vm_object) != NULL) { 2181 for (; obj; obj = obj->backing_object) 2182 if (obj == object) { 2183 return 1; 2184 } 2185 } 2186 return 0; 2187} 2188 2189static int 2190vm_object_in_map(vm_object_t object) 2191{ 2192 struct proc *p; 2193 2194 /* sx_slock(&allproc_lock); */ 2195 FOREACH_PROC_IN_SYSTEM(p) { 2196 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 2197 continue; 2198 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 2199 /* sx_sunlock(&allproc_lock); */ 2200 return 1; 2201 } 2202 } 2203 /* sx_sunlock(&allproc_lock); */ 2204 if (_vm_object_in_map(kernel_map, object, 0)) 2205 return 1; 2206 if (_vm_object_in_map(kmem_map, object, 0)) 2207 return 1; 2208 if (_vm_object_in_map(pager_map, object, 0)) 2209 return 1; 2210 if (_vm_object_in_map(buffer_map, object, 0)) 2211 return 1; 2212 return 0; 2213} 2214 2215DB_SHOW_COMMAND(vmochk, vm_object_check) 2216{ 2217 vm_object_t object; 2218 2219 /* 2220 * make sure that internal objs are in a map somewhere 2221 * and none have zero ref counts. 2222 */ 2223 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2224 if (object->handle == NULL && 2225 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 2226 if (object->ref_count == 0) { 2227 db_printf("vmochk: internal obj has zero ref count: %ld\n", 2228 (long)object->size); 2229 } 2230 if (!vm_object_in_map(object)) { 2231 db_printf( 2232 "vmochk: internal obj is not in a map: " 2233 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2234 object->ref_count, (u_long)object->size, 2235 (u_long)object->size, 2236 (void *)object->backing_object); 2237 } 2238 } 2239 } 2240} 2241 2242/* 2243 * vm_object_print: [ debug ] 2244 */ 2245DB_SHOW_COMMAND(object, vm_object_print_static) 2246{ 2247 /* XXX convert args. */ 2248 vm_object_t object = (vm_object_t)addr; 2249 boolean_t full = have_addr; 2250 2251 vm_page_t p; 2252 2253 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2254#define count was_count 2255 2256 int count; 2257 2258 if (object == NULL) 2259 return; 2260 2261 db_iprintf( 2262 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x uip %d charge %jx\n", 2263 object, (int)object->type, (uintmax_t)object->size, 2264 object->resident_page_count, object->ref_count, object->flags, 2265 object->uip ? object->uip->ui_uid : -1, (uintmax_t)object->charge); 2266 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2267 object->shadow_count, 2268 object->backing_object ? object->backing_object->ref_count : 0, 2269 object->backing_object, (uintmax_t)object->backing_object_offset); 2270 2271 if (!full) 2272 return; 2273 2274 db_indent += 2; 2275 count = 0; 2276 TAILQ_FOREACH(p, &object->memq, listq) { 2277 if (count == 0) 2278 db_iprintf("memory:="); 2279 else if (count == 6) { 2280 db_printf("\n"); 2281 db_iprintf(" ..."); 2282 count = 0; 2283 } else 2284 db_printf(","); 2285 count++; 2286 2287 db_printf("(off=0x%jx,page=0x%jx)", 2288 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2289 } 2290 if (count != 0) 2291 db_printf("\n"); 2292 db_indent -= 2; 2293} 2294 2295/* XXX. */ 2296#undef count 2297 2298/* XXX need this non-static entry for calling from vm_map_print. */ 2299void 2300vm_object_print( 2301 /* db_expr_t */ long addr, 2302 boolean_t have_addr, 2303 /* db_expr_t */ long count, 2304 char *modif) 2305{ 2306 vm_object_print_static(addr, have_addr, count, modif); 2307} 2308 2309DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2310{ 2311 vm_object_t object; 2312 vm_pindex_t fidx; 2313 vm_paddr_t pa; 2314 vm_page_t m, prev_m; 2315 int rcount, nl, c; 2316 2317 nl = 0; 2318 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2319 db_printf("new object: %p\n", (void *)object); 2320 if (nl > 18) { 2321 c = cngetc(); 2322 if (c != ' ') 2323 return; 2324 nl = 0; 2325 } 2326 nl++; 2327 rcount = 0; 2328 fidx = 0; 2329 pa = -1; 2330 TAILQ_FOREACH(m, &object->memq, listq) { 2331 if (m->pindex > 128) 2332 break; 2333 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL && 2334 prev_m->pindex + 1 != m->pindex) { 2335 if (rcount) { 2336 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2337 (long)fidx, rcount, (long)pa); 2338 if (nl > 18) { 2339 c = cngetc(); 2340 if (c != ' ') 2341 return; 2342 nl = 0; 2343 } 2344 nl++; 2345 rcount = 0; 2346 } 2347 } 2348 if (rcount && 2349 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2350 ++rcount; 2351 continue; 2352 } 2353 if (rcount) { 2354 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2355 (long)fidx, rcount, (long)pa); 2356 if (nl > 18) { 2357 c = cngetc(); 2358 if (c != ' ') 2359 return; 2360 nl = 0; 2361 } 2362 nl++; 2363 } 2364 fidx = m->pindex; 2365 pa = VM_PAGE_TO_PHYS(m); 2366 rcount = 1; 2367 } 2368 if (rcount) { 2369 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2370 (long)fidx, rcount, (long)pa); 2371 if (nl > 18) { 2372 c = cngetc(); 2373 if (c != ' ') 2374 return; 2375 nl = 0; 2376 } 2377 nl++; 2378 } 2379 } 2380} 2381#endif /* DDB */ 2382