vm_object.c revision 137242
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 137242 2004-11-05 05:40:45Z alc $"); 67 68#include <sys/param.h> 69#include <sys/systm.h> 70#include <sys/lock.h> 71#include <sys/mman.h> 72#include <sys/mount.h> 73#include <sys/kernel.h> 74#include <sys/sysctl.h> 75#include <sys/mutex.h> 76#include <sys/proc.h> /* for curproc, pageproc */ 77#include <sys/socket.h> 78#include <sys/vnode.h> 79#include <sys/vmmeter.h> 80#include <sys/sx.h> 81 82#include <vm/vm.h> 83#include <vm/vm_param.h> 84#include <vm/pmap.h> 85#include <vm/vm_map.h> 86#include <vm/vm_object.h> 87#include <vm/vm_page.h> 88#include <vm/vm_pageout.h> 89#include <vm/vm_pager.h> 90#include <vm/swap_pager.h> 91#include <vm/vm_kern.h> 92#include <vm/vm_extern.h> 93#include <vm/uma.h> 94 95#define EASY_SCAN_FACTOR 8 96 97#define MSYNC_FLUSH_HARDSEQ 0x01 98#define MSYNC_FLUSH_SOFTSEQ 0x02 99 100/* 101 * msync / VM object flushing optimizations 102 */ 103static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 104SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, 105 CTLFLAG_RW, &msync_flush_flags, 0, ""); 106 107static int old_msync; 108SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 109 "Use old (insecure) msync behavior"); 110 111static void vm_object_qcollapse(vm_object_t object); 112static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags); 113 114/* 115 * Virtual memory objects maintain the actual data 116 * associated with allocated virtual memory. A given 117 * page of memory exists within exactly one object. 118 * 119 * An object is only deallocated when all "references" 120 * are given up. Only one "reference" to a given 121 * region of an object should be writeable. 122 * 123 * Associated with each object is a list of all resident 124 * memory pages belonging to that object; this list is 125 * maintained by the "vm_page" module, and locked by the object's 126 * lock. 127 * 128 * Each object also records a "pager" routine which is 129 * used to retrieve (and store) pages to the proper backing 130 * storage. In addition, objects may be backed by other 131 * objects from which they were virtual-copied. 132 * 133 * The only items within the object structure which are 134 * modified after time of creation are: 135 * reference count locked by object's lock 136 * pager routine locked by object's lock 137 * 138 */ 139 140struct object_q vm_object_list; 141struct mtx vm_object_list_mtx; /* lock for object list and count */ 142 143struct vm_object kernel_object_store; 144struct vm_object kmem_object_store; 145 146static long object_collapses; 147static long object_bypasses; 148static int next_index; 149static uma_zone_t obj_zone; 150#define VM_OBJECTS_INIT 256 151 152static int vm_object_zinit(void *mem, int size, int flags); 153 154#ifdef INVARIANTS 155static void vm_object_zdtor(void *mem, int size, void *arg); 156 157static void 158vm_object_zdtor(void *mem, int size, void *arg) 159{ 160 vm_object_t object; 161 162 object = (vm_object_t)mem; 163 KASSERT(TAILQ_EMPTY(&object->memq), 164 ("object %p has resident pages", 165 object)); 166 KASSERT(object->paging_in_progress == 0, 167 ("object %p paging_in_progress = %d", 168 object, object->paging_in_progress)); 169 KASSERT(object->resident_page_count == 0, 170 ("object %p resident_page_count = %d", 171 object, object->resident_page_count)); 172 KASSERT(object->shadow_count == 0, 173 ("object %p shadow_count = %d", 174 object, object->shadow_count)); 175} 176#endif 177 178static int 179vm_object_zinit(void *mem, int size, int flags) 180{ 181 vm_object_t object; 182 183 object = (vm_object_t)mem; 184 bzero(&object->mtx, sizeof(object->mtx)); 185 VM_OBJECT_LOCK_INIT(object, "standard object"); 186 187 /* These are true for any object that has been freed */ 188 object->paging_in_progress = 0; 189 object->resident_page_count = 0; 190 object->shadow_count = 0; 191 return (0); 192} 193 194void 195_vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object) 196{ 197 int incr; 198 199 TAILQ_INIT(&object->memq); 200 LIST_INIT(&object->shadow_head); 201 202 object->root = NULL; 203 object->type = type; 204 object->size = size; 205 object->generation = 1; 206 object->ref_count = 1; 207 object->flags = 0; 208 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 209 object->flags = OBJ_ONEMAPPING; 210 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 211 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 212 else 213 incr = size; 214 do 215 object->pg_color = next_index; 216 while (!atomic_cmpset_int(&next_index, object->pg_color, 217 (object->pg_color + incr) & PQ_L2_MASK)); 218 object->handle = NULL; 219 object->backing_object = NULL; 220 object->backing_object_offset = (vm_ooffset_t) 0; 221 222 mtx_lock(&vm_object_list_mtx); 223 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 224 mtx_unlock(&vm_object_list_mtx); 225} 226 227/* 228 * vm_object_init: 229 * 230 * Initialize the VM objects module. 231 */ 232void 233vm_object_init(void) 234{ 235 TAILQ_INIT(&vm_object_list); 236 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 237 238 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object"); 239 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 240 kernel_object); 241 242 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object"); 243 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 244 kmem_object); 245 246 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 247#ifdef INVARIANTS 248 vm_object_zdtor, 249#else 250 NULL, 251#endif 252 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 253 uma_prealloc(obj_zone, VM_OBJECTS_INIT); 254} 255 256void 257vm_object_clear_flag(vm_object_t object, u_short bits) 258{ 259 260 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 261 object->flags &= ~bits; 262} 263 264void 265vm_object_pip_add(vm_object_t object, short i) 266{ 267 268 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 269 object->paging_in_progress += i; 270} 271 272void 273vm_object_pip_subtract(vm_object_t object, short i) 274{ 275 276 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 277 object->paging_in_progress -= i; 278} 279 280void 281vm_object_pip_wakeup(vm_object_t object) 282{ 283 284 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 285 object->paging_in_progress--; 286 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 287 vm_object_clear_flag(object, OBJ_PIPWNT); 288 wakeup(object); 289 } 290} 291 292void 293vm_object_pip_wakeupn(vm_object_t object, short i) 294{ 295 296 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 297 if (i) 298 object->paging_in_progress -= i; 299 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 300 vm_object_clear_flag(object, OBJ_PIPWNT); 301 wakeup(object); 302 } 303} 304 305void 306vm_object_pip_wait(vm_object_t object, char *waitid) 307{ 308 309 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 310 while (object->paging_in_progress) { 311 object->flags |= OBJ_PIPWNT; 312 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 313 } 314} 315 316/* 317 * vm_object_allocate_wait 318 * 319 * Return a new object with the given size, and give the user the 320 * option of waiting for it to complete or failing if the needed 321 * memory isn't available. 322 */ 323vm_object_t 324vm_object_allocate_wait(objtype_t type, vm_pindex_t size, int flags) 325{ 326 vm_object_t result; 327 328 result = (vm_object_t) uma_zalloc(obj_zone, flags); 329 330 if (result != NULL) 331 _vm_object_allocate(type, size, result); 332 333 return (result); 334} 335 336/* 337 * vm_object_allocate: 338 * 339 * Returns a new object with the given size. 340 */ 341vm_object_t 342vm_object_allocate(objtype_t type, vm_pindex_t size) 343{ 344 return(vm_object_allocate_wait(type, size, M_WAITOK)); 345} 346 347 348/* 349 * vm_object_reference: 350 * 351 * Gets another reference to the given object. Note: OBJ_DEAD 352 * objects can be referenced during final cleaning. 353 */ 354void 355vm_object_reference(vm_object_t object) 356{ 357 struct vnode *vp; 358 int flags; 359 360 if (object == NULL) 361 return; 362 VM_OBJECT_LOCK(object); 363 object->ref_count++; 364 if (object->type == OBJT_VNODE) { 365 vp = object->handle; 366 VI_LOCK(vp); 367 VM_OBJECT_UNLOCK(object); 368 for (flags = LK_INTERLOCK; vget(vp, flags, curthread); 369 flags = 0) 370 printf("vm_object_reference: delay in vget\n"); 371 } else 372 VM_OBJECT_UNLOCK(object); 373} 374 375/* 376 * vm_object_reference_locked: 377 * 378 * Gets another reference to the given object. 379 * 380 * The object must be locked. 381 */ 382void 383vm_object_reference_locked(vm_object_t object) 384{ 385 struct vnode *vp; 386 387 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 388 KASSERT((object->flags & OBJ_DEAD) == 0, 389 ("vm_object_reference_locked: dead object referenced")); 390 object->ref_count++; 391 if (object->type == OBJT_VNODE) { 392 vp = object->handle; 393 vref(vp); 394 } 395} 396 397/* 398 * Handle deallocating an object of type OBJT_VNODE. 399 */ 400void 401vm_object_vndeallocate(vm_object_t object) 402{ 403 struct vnode *vp = (struct vnode *) object->handle; 404 405 GIANT_REQUIRED; 406 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 407 KASSERT(object->type == OBJT_VNODE, 408 ("vm_object_vndeallocate: not a vnode object")); 409 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 410#ifdef INVARIANTS 411 if (object->ref_count == 0) { 412 vprint("vm_object_vndeallocate", vp); 413 panic("vm_object_vndeallocate: bad object reference count"); 414 } 415#endif 416 417 object->ref_count--; 418 if (object->ref_count == 0) { 419 mp_fixme("Unlocked vflag access."); 420 vp->v_vflag &= ~VV_TEXT; 421 } 422 VM_OBJECT_UNLOCK(object); 423 /* 424 * vrele may need a vop lock 425 */ 426 vrele(vp); 427} 428 429/* 430 * vm_object_deallocate: 431 * 432 * Release a reference to the specified object, 433 * gained either through a vm_object_allocate 434 * or a vm_object_reference call. When all references 435 * are gone, storage associated with this object 436 * may be relinquished. 437 * 438 * No object may be locked. 439 */ 440void 441vm_object_deallocate(vm_object_t object) 442{ 443 vm_object_t temp; 444 445 while (object != NULL) { 446 /* 447 * In general, the object should be locked when working with 448 * its type. In this case, in order to maintain proper lock 449 * ordering, an exception is possible because a vnode-backed 450 * object never changes its type. 451 */ 452 if (object->type == OBJT_VNODE) 453 mtx_lock(&Giant); 454 VM_OBJECT_LOCK(object); 455 if (object->type == OBJT_VNODE) { 456 vm_object_vndeallocate(object); 457 mtx_unlock(&Giant); 458 return; 459 } 460 461 KASSERT(object->ref_count != 0, 462 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 463 464 /* 465 * If the reference count goes to 0 we start calling 466 * vm_object_terminate() on the object chain. 467 * A ref count of 1 may be a special case depending on the 468 * shadow count being 0 or 1. 469 */ 470 object->ref_count--; 471 if (object->ref_count > 1) { 472 VM_OBJECT_UNLOCK(object); 473 return; 474 } else if (object->ref_count == 1) { 475 if (object->shadow_count == 0) { 476 vm_object_set_flag(object, OBJ_ONEMAPPING); 477 } else if ((object->shadow_count == 1) && 478 (object->handle == NULL) && 479 (object->type == OBJT_DEFAULT || 480 object->type == OBJT_SWAP)) { 481 vm_object_t robject; 482 483 robject = LIST_FIRST(&object->shadow_head); 484 KASSERT(robject != NULL, 485 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 486 object->ref_count, 487 object->shadow_count)); 488 if (!VM_OBJECT_TRYLOCK(robject)) { 489 /* 490 * Avoid a potential deadlock. 491 */ 492 object->ref_count++; 493 VM_OBJECT_UNLOCK(object); 494 /* 495 * More likely than not the thread 496 * holding robject's lock has lower 497 * priority than the current thread. 498 * Let the lower priority thread run. 499 */ 500 tsleep(&proc0, PVM, "vmo_de", 1); 501 continue; 502 } 503 if ((robject->handle == NULL) && 504 (robject->type == OBJT_DEFAULT || 505 robject->type == OBJT_SWAP)) { 506 507 robject->ref_count++; 508retry: 509 if (robject->paging_in_progress) { 510 VM_OBJECT_UNLOCK(object); 511 vm_object_pip_wait(robject, 512 "objde1"); 513 VM_OBJECT_LOCK(object); 514 goto retry; 515 } else if (object->paging_in_progress) { 516 VM_OBJECT_UNLOCK(robject); 517 object->flags |= OBJ_PIPWNT; 518 msleep(object, 519 VM_OBJECT_MTX(object), 520 PDROP | PVM, "objde2", 0); 521 VM_OBJECT_LOCK(robject); 522 VM_OBJECT_LOCK(object); 523 goto retry; 524 } 525 VM_OBJECT_UNLOCK(object); 526 if (robject->ref_count == 1) { 527 robject->ref_count--; 528 object = robject; 529 goto doterm; 530 } 531 object = robject; 532 vm_object_collapse(object); 533 VM_OBJECT_UNLOCK(object); 534 continue; 535 } 536 VM_OBJECT_UNLOCK(robject); 537 } 538 VM_OBJECT_UNLOCK(object); 539 return; 540 } 541doterm: 542 temp = object->backing_object; 543 if (temp != NULL) { 544 VM_OBJECT_LOCK(temp); 545 LIST_REMOVE(object, shadow_list); 546 temp->shadow_count--; 547 temp->generation++; 548 VM_OBJECT_UNLOCK(temp); 549 object->backing_object = NULL; 550 } 551 /* 552 * Don't double-terminate, we could be in a termination 553 * recursion due to the terminate having to sync data 554 * to disk. 555 */ 556 if ((object->flags & OBJ_DEAD) == 0) 557 vm_object_terminate(object); 558 else 559 VM_OBJECT_UNLOCK(object); 560 object = temp; 561 } 562} 563 564/* 565 * vm_object_terminate actually destroys the specified object, freeing 566 * up all previously used resources. 567 * 568 * The object must be locked. 569 * This routine may block. 570 */ 571void 572vm_object_terminate(vm_object_t object) 573{ 574 vm_page_t p; 575 576 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 577 578 /* 579 * Make sure no one uses us. 580 */ 581 vm_object_set_flag(object, OBJ_DEAD); 582 583 /* 584 * wait for the pageout daemon to be done with the object 585 */ 586 vm_object_pip_wait(object, "objtrm"); 587 588 KASSERT(!object->paging_in_progress, 589 ("vm_object_terminate: pageout in progress")); 590 591 /* 592 * Clean and free the pages, as appropriate. All references to the 593 * object are gone, so we don't need to lock it. 594 */ 595 if (object->type == OBJT_VNODE) { 596 struct vnode *vp = (struct vnode *)object->handle; 597 598 /* 599 * Clean pages and flush buffers. 600 */ 601 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 602 VM_OBJECT_UNLOCK(object); 603 604 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 605 606 VM_OBJECT_LOCK(object); 607 } 608 609 KASSERT(object->ref_count == 0, 610 ("vm_object_terminate: object with references, ref_count=%d", 611 object->ref_count)); 612 613 /* 614 * Now free any remaining pages. For internal objects, this also 615 * removes them from paging queues. Don't free wired pages, just 616 * remove them from the object. 617 */ 618 vm_page_lock_queues(); 619 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 620 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0, 621 ("vm_object_terminate: freeing busy page %p " 622 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags)); 623 if (p->wire_count == 0) { 624 vm_page_free(p); 625 cnt.v_pfree++; 626 } else { 627 vm_page_remove(p); 628 } 629 } 630 vm_page_unlock_queues(); 631 632 /* 633 * Let the pager know object is dead. 634 */ 635 vm_pager_deallocate(object); 636 VM_OBJECT_UNLOCK(object); 637 638 /* 639 * Remove the object from the global object list. 640 */ 641 mtx_lock(&vm_object_list_mtx); 642 TAILQ_REMOVE(&vm_object_list, object, object_list); 643 mtx_unlock(&vm_object_list_mtx); 644 645 wakeup(object); 646 647 /* 648 * Free the space for the object. 649 */ 650 uma_zfree(obj_zone, object); 651} 652 653/* 654 * vm_object_page_clean 655 * 656 * Clean all dirty pages in the specified range of object. Leaves page 657 * on whatever queue it is currently on. If NOSYNC is set then do not 658 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 659 * leaving the object dirty. 660 * 661 * When stuffing pages asynchronously, allow clustering. XXX we need a 662 * synchronous clustering mode implementation. 663 * 664 * Odd semantics: if start == end, we clean everything. 665 * 666 * The object must be locked. 667 */ 668void 669vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 670{ 671 vm_page_t p, np; 672 vm_pindex_t tstart, tend; 673 vm_pindex_t pi; 674 int clearobjflags; 675 int pagerflags; 676 int curgeneration; 677 678 GIANT_REQUIRED; 679 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 680 if (object->type != OBJT_VNODE || 681 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 682 return; 683 684 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 685 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 686 687 vm_object_set_flag(object, OBJ_CLEANING); 688 689 tstart = start; 690 if (end == 0) { 691 tend = object->size; 692 } else { 693 tend = end; 694 } 695 696 vm_page_lock_queues(); 697 /* 698 * If the caller is smart and only msync()s a range he knows is 699 * dirty, we may be able to avoid an object scan. This results in 700 * a phenominal improvement in performance. We cannot do this 701 * as a matter of course because the object may be huge - e.g. 702 * the size might be in the gigabytes or terrabytes. 703 */ 704 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 705 vm_pindex_t tscan; 706 int scanlimit; 707 int scanreset; 708 709 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 710 if (scanreset < 16) 711 scanreset = 16; 712 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 713 714 scanlimit = scanreset; 715 tscan = tstart; 716 while (tscan < tend) { 717 curgeneration = object->generation; 718 p = vm_page_lookup(object, tscan); 719 if (p == NULL || p->valid == 0 || 720 (p->queue - p->pc) == PQ_CACHE) { 721 if (--scanlimit == 0) 722 break; 723 ++tscan; 724 continue; 725 } 726 vm_page_test_dirty(p); 727 if ((p->dirty & p->valid) == 0) { 728 if (--scanlimit == 0) 729 break; 730 ++tscan; 731 continue; 732 } 733 /* 734 * If we have been asked to skip nosync pages and 735 * this is a nosync page, we can't continue. 736 */ 737 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 738 if (--scanlimit == 0) 739 break; 740 ++tscan; 741 continue; 742 } 743 scanlimit = scanreset; 744 745 /* 746 * This returns 0 if it was unable to busy the first 747 * page (i.e. had to sleep). 748 */ 749 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 750 } 751 752 /* 753 * If everything was dirty and we flushed it successfully, 754 * and the requested range is not the entire object, we 755 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 756 * return immediately. 757 */ 758 if (tscan >= tend && (tstart || tend < object->size)) { 759 vm_page_unlock_queues(); 760 vm_object_clear_flag(object, OBJ_CLEANING); 761 return; 762 } 763 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 764 } 765 766 /* 767 * Generally set CLEANCHK interlock and make the page read-only so 768 * we can then clear the object flags. 769 * 770 * However, if this is a nosync mmap then the object is likely to 771 * stay dirty so do not mess with the page and do not clear the 772 * object flags. 773 */ 774 clearobjflags = 1; 775 TAILQ_FOREACH(p, &object->memq, listq) { 776 vm_page_flag_set(p, PG_CLEANCHK); 777 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 778 clearobjflags = 0; 779 else 780 pmap_page_protect(p, VM_PROT_READ); 781 } 782 783 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 784 struct vnode *vp; 785 786 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 787 if (object->type == OBJT_VNODE && 788 (vp = (struct vnode *)object->handle) != NULL) { 789 VI_LOCK(vp); 790 if (vp->v_iflag & VI_OBJDIRTY) 791 vp->v_iflag &= ~VI_OBJDIRTY; 792 VI_UNLOCK(vp); 793 } 794 } 795 796rescan: 797 curgeneration = object->generation; 798 799 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 800 int n; 801 802 np = TAILQ_NEXT(p, listq); 803 804again: 805 pi = p->pindex; 806 if (((p->flags & PG_CLEANCHK) == 0) || 807 (pi < tstart) || (pi >= tend) || 808 (p->valid == 0) || 809 ((p->queue - p->pc) == PQ_CACHE)) { 810 vm_page_flag_clear(p, PG_CLEANCHK); 811 continue; 812 } 813 814 vm_page_test_dirty(p); 815 if ((p->dirty & p->valid) == 0) { 816 vm_page_flag_clear(p, PG_CLEANCHK); 817 continue; 818 } 819 820 /* 821 * If we have been asked to skip nosync pages and this is a 822 * nosync page, skip it. Note that the object flags were 823 * not cleared in this case so we do not have to set them. 824 */ 825 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 826 vm_page_flag_clear(p, PG_CLEANCHK); 827 continue; 828 } 829 830 n = vm_object_page_collect_flush(object, p, 831 curgeneration, pagerflags); 832 if (n == 0) 833 goto rescan; 834 835 if (object->generation != curgeneration) 836 goto rescan; 837 838 /* 839 * Try to optimize the next page. If we can't we pick up 840 * our (random) scan where we left off. 841 */ 842 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 843 if ((p = vm_page_lookup(object, pi + n)) != NULL) 844 goto again; 845 } 846 } 847 vm_page_unlock_queues(); 848#if 0 849 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 850#endif 851 852 vm_object_clear_flag(object, OBJ_CLEANING); 853 return; 854} 855 856static int 857vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 858{ 859 int runlen; 860 int maxf; 861 int chkb; 862 int maxb; 863 int i; 864 vm_pindex_t pi; 865 vm_page_t maf[vm_pageout_page_count]; 866 vm_page_t mab[vm_pageout_page_count]; 867 vm_page_t ma[vm_pageout_page_count]; 868 869 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 870 pi = p->pindex; 871 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 872 vm_page_lock_queues(); 873 if (object->generation != curgeneration) { 874 return(0); 875 } 876 } 877 maxf = 0; 878 for(i = 1; i < vm_pageout_page_count; i++) { 879 vm_page_t tp; 880 881 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 882 if ((tp->flags & PG_BUSY) || 883 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 884 (tp->flags & PG_CLEANCHK) == 0) || 885 (tp->busy != 0)) 886 break; 887 if((tp->queue - tp->pc) == PQ_CACHE) { 888 vm_page_flag_clear(tp, PG_CLEANCHK); 889 break; 890 } 891 vm_page_test_dirty(tp); 892 if ((tp->dirty & tp->valid) == 0) { 893 vm_page_flag_clear(tp, PG_CLEANCHK); 894 break; 895 } 896 maf[ i - 1 ] = tp; 897 maxf++; 898 continue; 899 } 900 break; 901 } 902 903 maxb = 0; 904 chkb = vm_pageout_page_count - maxf; 905 if (chkb) { 906 for(i = 1; i < chkb;i++) { 907 vm_page_t tp; 908 909 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 910 if ((tp->flags & PG_BUSY) || 911 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 912 (tp->flags & PG_CLEANCHK) == 0) || 913 (tp->busy != 0)) 914 break; 915 if ((tp->queue - tp->pc) == PQ_CACHE) { 916 vm_page_flag_clear(tp, PG_CLEANCHK); 917 break; 918 } 919 vm_page_test_dirty(tp); 920 if ((tp->dirty & tp->valid) == 0) { 921 vm_page_flag_clear(tp, PG_CLEANCHK); 922 break; 923 } 924 mab[ i - 1 ] = tp; 925 maxb++; 926 continue; 927 } 928 break; 929 } 930 } 931 932 for(i = 0; i < maxb; i++) { 933 int index = (maxb - i) - 1; 934 ma[index] = mab[i]; 935 vm_page_flag_clear(ma[index], PG_CLEANCHK); 936 } 937 vm_page_flag_clear(p, PG_CLEANCHK); 938 ma[maxb] = p; 939 for(i = 0; i < maxf; i++) { 940 int index = (maxb + i) + 1; 941 ma[index] = maf[i]; 942 vm_page_flag_clear(ma[index], PG_CLEANCHK); 943 } 944 runlen = maxb + maxf + 1; 945 946 vm_pageout_flush(ma, runlen, pagerflags); 947 for (i = 0; i < runlen; i++) { 948 if (ma[i]->valid & ma[i]->dirty) { 949 pmap_page_protect(ma[i], VM_PROT_READ); 950 vm_page_flag_set(ma[i], PG_CLEANCHK); 951 952 /* 953 * maxf will end up being the actual number of pages 954 * we wrote out contiguously, non-inclusive of the 955 * first page. We do not count look-behind pages. 956 */ 957 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 958 maxf = i - maxb - 1; 959 } 960 } 961 return(maxf + 1); 962} 963 964/* 965 * Note that there is absolutely no sense in writing out 966 * anonymous objects, so we track down the vnode object 967 * to write out. 968 * We invalidate (remove) all pages from the address space 969 * for semantic correctness. 970 * 971 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 972 * may start out with a NULL object. 973 */ 974void 975vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 976 boolean_t syncio, boolean_t invalidate) 977{ 978 vm_object_t backing_object; 979 struct vnode *vp; 980 int flags; 981 982 if (object == NULL) 983 return; 984 VM_OBJECT_LOCK(object); 985 while ((backing_object = object->backing_object) != NULL) { 986 VM_OBJECT_LOCK(backing_object); 987 offset += object->backing_object_offset; 988 VM_OBJECT_UNLOCK(object); 989 object = backing_object; 990 if (object->size < OFF_TO_IDX(offset + size)) 991 size = IDX_TO_OFF(object->size) - offset; 992 } 993 /* 994 * Flush pages if writing is allowed, invalidate them 995 * if invalidation requested. Pages undergoing I/O 996 * will be ignored by vm_object_page_remove(). 997 * 998 * We cannot lock the vnode and then wait for paging 999 * to complete without deadlocking against vm_fault. 1000 * Instead we simply call vm_object_page_remove() and 1001 * allow it to block internally on a page-by-page 1002 * basis when it encounters pages undergoing async 1003 * I/O. 1004 */ 1005 if (object->type == OBJT_VNODE && 1006 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1007 vp = object->handle; 1008 VM_OBJECT_UNLOCK(object); 1009 mtx_lock(&Giant); 1010 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 1011 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1012 flags |= invalidate ? OBJPC_INVAL : 0; 1013 VM_OBJECT_LOCK(object); 1014 vm_object_page_clean(object, 1015 OFF_TO_IDX(offset), 1016 OFF_TO_IDX(offset + size + PAGE_MASK), 1017 flags); 1018 VM_OBJECT_UNLOCK(object); 1019 VOP_UNLOCK(vp, 0, curthread); 1020 mtx_unlock(&Giant); 1021 VM_OBJECT_LOCK(object); 1022 } 1023 if ((object->type == OBJT_VNODE || 1024 object->type == OBJT_DEVICE) && invalidate) { 1025 boolean_t purge; 1026 purge = old_msync || (object->type == OBJT_DEVICE); 1027 vm_object_page_remove(object, 1028 OFF_TO_IDX(offset), 1029 OFF_TO_IDX(offset + size + PAGE_MASK), 1030 purge ? FALSE : TRUE); 1031 } 1032 VM_OBJECT_UNLOCK(object); 1033} 1034 1035/* 1036 * vm_object_madvise: 1037 * 1038 * Implements the madvise function at the object/page level. 1039 * 1040 * MADV_WILLNEED (any object) 1041 * 1042 * Activate the specified pages if they are resident. 1043 * 1044 * MADV_DONTNEED (any object) 1045 * 1046 * Deactivate the specified pages if they are resident. 1047 * 1048 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1049 * OBJ_ONEMAPPING only) 1050 * 1051 * Deactivate and clean the specified pages if they are 1052 * resident. This permits the process to reuse the pages 1053 * without faulting or the kernel to reclaim the pages 1054 * without I/O. 1055 */ 1056void 1057vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1058{ 1059 vm_pindex_t end, tpindex; 1060 vm_object_t backing_object, tobject; 1061 vm_page_t m; 1062 1063 if (object == NULL) 1064 return; 1065 VM_OBJECT_LOCK(object); 1066 end = pindex + count; 1067 /* 1068 * Locate and adjust resident pages 1069 */ 1070 for (; pindex < end; pindex += 1) { 1071relookup: 1072 tobject = object; 1073 tpindex = pindex; 1074shadowlookup: 1075 /* 1076 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1077 * and those pages must be OBJ_ONEMAPPING. 1078 */ 1079 if (advise == MADV_FREE) { 1080 if ((tobject->type != OBJT_DEFAULT && 1081 tobject->type != OBJT_SWAP) || 1082 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1083 goto unlock_tobject; 1084 } 1085 } 1086 m = vm_page_lookup(tobject, tpindex); 1087 if (m == NULL) { 1088 /* 1089 * There may be swap even if there is no backing page 1090 */ 1091 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1092 swap_pager_freespace(tobject, tpindex, 1); 1093 /* 1094 * next object 1095 */ 1096 backing_object = tobject->backing_object; 1097 if (backing_object == NULL) 1098 goto unlock_tobject; 1099 VM_OBJECT_LOCK(backing_object); 1100 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1101 if (tobject != object) 1102 VM_OBJECT_UNLOCK(tobject); 1103 tobject = backing_object; 1104 goto shadowlookup; 1105 } 1106 /* 1107 * If the page is busy or not in a normal active state, 1108 * we skip it. If the page is not managed there are no 1109 * page queues to mess with. Things can break if we mess 1110 * with pages in any of the below states. 1111 */ 1112 vm_page_lock_queues(); 1113 if (m->hold_count || 1114 m->wire_count || 1115 (m->flags & PG_UNMANAGED) || 1116 m->valid != VM_PAGE_BITS_ALL) { 1117 vm_page_unlock_queues(); 1118 goto unlock_tobject; 1119 } 1120 if ((m->flags & PG_BUSY) || m->busy) { 1121 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1122 if (object != tobject) 1123 VM_OBJECT_UNLOCK(object); 1124 VM_OBJECT_UNLOCK(tobject); 1125 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "madvpo", 0); 1126 VM_OBJECT_LOCK(object); 1127 goto relookup; 1128 } 1129 if (advise == MADV_WILLNEED) { 1130 vm_page_activate(m); 1131 } else if (advise == MADV_DONTNEED) { 1132 vm_page_dontneed(m); 1133 } else if (advise == MADV_FREE) { 1134 /* 1135 * Mark the page clean. This will allow the page 1136 * to be freed up by the system. However, such pages 1137 * are often reused quickly by malloc()/free() 1138 * so we do not do anything that would cause 1139 * a page fault if we can help it. 1140 * 1141 * Specifically, we do not try to actually free 1142 * the page now nor do we try to put it in the 1143 * cache (which would cause a page fault on reuse). 1144 * 1145 * But we do make the page is freeable as we 1146 * can without actually taking the step of unmapping 1147 * it. 1148 */ 1149 pmap_clear_modify(m); 1150 m->dirty = 0; 1151 m->act_count = 0; 1152 vm_page_dontneed(m); 1153 } 1154 vm_page_unlock_queues(); 1155 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1156 swap_pager_freespace(tobject, tpindex, 1); 1157unlock_tobject: 1158 if (tobject != object) 1159 VM_OBJECT_UNLOCK(tobject); 1160 } 1161 VM_OBJECT_UNLOCK(object); 1162} 1163 1164/* 1165 * vm_object_shadow: 1166 * 1167 * Create a new object which is backed by the 1168 * specified existing object range. The source 1169 * object reference is deallocated. 1170 * 1171 * The new object and offset into that object 1172 * are returned in the source parameters. 1173 */ 1174void 1175vm_object_shadow( 1176 vm_object_t *object, /* IN/OUT */ 1177 vm_ooffset_t *offset, /* IN/OUT */ 1178 vm_size_t length) 1179{ 1180 vm_object_t source; 1181 vm_object_t result; 1182 1183 source = *object; 1184 1185 /* 1186 * Don't create the new object if the old object isn't shared. 1187 */ 1188 if (source != NULL) { 1189 VM_OBJECT_LOCK(source); 1190 if (source->ref_count == 1 && 1191 source->handle == NULL && 1192 (source->type == OBJT_DEFAULT || 1193 source->type == OBJT_SWAP)) { 1194 VM_OBJECT_UNLOCK(source); 1195 return; 1196 } 1197 VM_OBJECT_UNLOCK(source); 1198 } 1199 1200 /* 1201 * Allocate a new object with the given length. 1202 */ 1203 result = vm_object_allocate(OBJT_DEFAULT, length); 1204 1205 /* 1206 * The new object shadows the source object, adding a reference to it. 1207 * Our caller changes his reference to point to the new object, 1208 * removing a reference to the source object. Net result: no change 1209 * of reference count. 1210 * 1211 * Try to optimize the result object's page color when shadowing 1212 * in order to maintain page coloring consistency in the combined 1213 * shadowed object. 1214 */ 1215 result->backing_object = source; 1216 /* 1217 * Store the offset into the source object, and fix up the offset into 1218 * the new object. 1219 */ 1220 result->backing_object_offset = *offset; 1221 if (source != NULL) { 1222 VM_OBJECT_LOCK(source); 1223 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1224 source->shadow_count++; 1225 source->generation++; 1226 if (length < source->size) 1227 length = source->size; 1228 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 || 1229 source->generation > 1) 1230 length = PQ_L2_SIZE / 3 + PQ_PRIME1; 1231 result->pg_color = (source->pg_color + 1232 length * source->generation) & PQ_L2_MASK; 1233 VM_OBJECT_UNLOCK(source); 1234 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & 1235 PQ_L2_MASK; 1236 } 1237 1238 1239 /* 1240 * Return the new things 1241 */ 1242 *offset = 0; 1243 *object = result; 1244} 1245 1246/* 1247 * vm_object_split: 1248 * 1249 * Split the pages in a map entry into a new object. This affords 1250 * easier removal of unused pages, and keeps object inheritance from 1251 * being a negative impact on memory usage. 1252 */ 1253void 1254vm_object_split(vm_map_entry_t entry) 1255{ 1256 vm_page_t m; 1257 vm_object_t orig_object, new_object, source; 1258 vm_pindex_t offidxstart, offidxend; 1259 vm_size_t idx, size; 1260 1261 orig_object = entry->object.vm_object; 1262 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1263 return; 1264 if (orig_object->ref_count <= 1) 1265 return; 1266 VM_OBJECT_UNLOCK(orig_object); 1267 1268 offidxstart = OFF_TO_IDX(entry->offset); 1269 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); 1270 size = offidxend - offidxstart; 1271 1272 /* 1273 * If swap_pager_copy() is later called, it will convert new_object 1274 * into a swap object. 1275 */ 1276 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1277 1278 VM_OBJECT_LOCK(new_object); 1279 VM_OBJECT_LOCK(orig_object); 1280 source = orig_object->backing_object; 1281 if (source != NULL) { 1282 VM_OBJECT_LOCK(source); 1283 LIST_INSERT_HEAD(&source->shadow_head, 1284 new_object, shadow_list); 1285 source->shadow_count++; 1286 source->generation++; 1287 vm_object_reference_locked(source); /* for new_object */ 1288 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1289 VM_OBJECT_UNLOCK(source); 1290 new_object->backing_object_offset = 1291 orig_object->backing_object_offset + entry->offset; 1292 new_object->backing_object = source; 1293 } 1294 for (idx = 0; idx < size; idx++) { 1295 retry: 1296 m = vm_page_lookup(orig_object, offidxstart + idx); 1297 if (m == NULL) 1298 continue; 1299 1300 /* 1301 * We must wait for pending I/O to complete before we can 1302 * rename the page. 1303 * 1304 * We do not have to VM_PROT_NONE the page as mappings should 1305 * not be changed by this operation. 1306 */ 1307 vm_page_lock_queues(); 1308 if ((m->flags & PG_BUSY) || m->busy) { 1309 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1310 VM_OBJECT_UNLOCK(orig_object); 1311 VM_OBJECT_UNLOCK(new_object); 1312 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0); 1313 VM_OBJECT_LOCK(new_object); 1314 VM_OBJECT_LOCK(orig_object); 1315 goto retry; 1316 } 1317 vm_page_rename(m, new_object, idx); 1318 /* page automatically made dirty by rename and cache handled */ 1319 vm_page_busy(m); 1320 vm_page_unlock_queues(); 1321 } 1322 if (orig_object->type == OBJT_SWAP) { 1323 /* 1324 * swap_pager_copy() can sleep, in which case the orig_object's 1325 * and new_object's locks are released and reacquired. 1326 */ 1327 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1328 } 1329 VM_OBJECT_UNLOCK(orig_object); 1330 vm_page_lock_queues(); 1331 TAILQ_FOREACH(m, &new_object->memq, listq) 1332 vm_page_wakeup(m); 1333 vm_page_unlock_queues(); 1334 VM_OBJECT_UNLOCK(new_object); 1335 entry->object.vm_object = new_object; 1336 entry->offset = 0LL; 1337 vm_object_deallocate(orig_object); 1338 VM_OBJECT_LOCK(new_object); 1339} 1340 1341#define OBSC_TEST_ALL_SHADOWED 0x0001 1342#define OBSC_COLLAPSE_NOWAIT 0x0002 1343#define OBSC_COLLAPSE_WAIT 0x0004 1344 1345static int 1346vm_object_backing_scan(vm_object_t object, int op) 1347{ 1348 int r = 1; 1349 vm_page_t p; 1350 vm_object_t backing_object; 1351 vm_pindex_t backing_offset_index; 1352 1353 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1354 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1355 1356 backing_object = object->backing_object; 1357 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1358 1359 /* 1360 * Initial conditions 1361 */ 1362 if (op & OBSC_TEST_ALL_SHADOWED) { 1363 /* 1364 * We do not want to have to test for the existence of 1365 * swap pages in the backing object. XXX but with the 1366 * new swapper this would be pretty easy to do. 1367 * 1368 * XXX what about anonymous MAP_SHARED memory that hasn't 1369 * been ZFOD faulted yet? If we do not test for this, the 1370 * shadow test may succeed! XXX 1371 */ 1372 if (backing_object->type != OBJT_DEFAULT) { 1373 return (0); 1374 } 1375 } 1376 if (op & OBSC_COLLAPSE_WAIT) { 1377 vm_object_set_flag(backing_object, OBJ_DEAD); 1378 } 1379 1380 /* 1381 * Our scan 1382 */ 1383 p = TAILQ_FIRST(&backing_object->memq); 1384 while (p) { 1385 vm_page_t next = TAILQ_NEXT(p, listq); 1386 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1387 1388 if (op & OBSC_TEST_ALL_SHADOWED) { 1389 vm_page_t pp; 1390 1391 /* 1392 * Ignore pages outside the parent object's range 1393 * and outside the parent object's mapping of the 1394 * backing object. 1395 * 1396 * note that we do not busy the backing object's 1397 * page. 1398 */ 1399 if ( 1400 p->pindex < backing_offset_index || 1401 new_pindex >= object->size 1402 ) { 1403 p = next; 1404 continue; 1405 } 1406 1407 /* 1408 * See if the parent has the page or if the parent's 1409 * object pager has the page. If the parent has the 1410 * page but the page is not valid, the parent's 1411 * object pager must have the page. 1412 * 1413 * If this fails, the parent does not completely shadow 1414 * the object and we might as well give up now. 1415 */ 1416 1417 pp = vm_page_lookup(object, new_pindex); 1418 if ( 1419 (pp == NULL || pp->valid == 0) && 1420 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1421 ) { 1422 r = 0; 1423 break; 1424 } 1425 } 1426 1427 /* 1428 * Check for busy page 1429 */ 1430 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1431 vm_page_t pp; 1432 1433 vm_page_lock_queues(); 1434 if (op & OBSC_COLLAPSE_NOWAIT) { 1435 if ((p->flags & PG_BUSY) || 1436 !p->valid || 1437 p->hold_count || 1438 p->wire_count || 1439 p->busy) { 1440 vm_page_unlock_queues(); 1441 p = next; 1442 continue; 1443 } 1444 } else if (op & OBSC_COLLAPSE_WAIT) { 1445 if ((p->flags & PG_BUSY) || p->busy) { 1446 vm_page_flag_set(p, 1447 PG_WANTED | PG_REFERENCED); 1448 VM_OBJECT_UNLOCK(backing_object); 1449 VM_OBJECT_UNLOCK(object); 1450 msleep(p, &vm_page_queue_mtx, 1451 PDROP | PVM, "vmocol", 0); 1452 VM_OBJECT_LOCK(object); 1453 VM_OBJECT_LOCK(backing_object); 1454 /* 1455 * If we slept, anything could have 1456 * happened. Since the object is 1457 * marked dead, the backing offset 1458 * should not have changed so we 1459 * just restart our scan. 1460 */ 1461 p = TAILQ_FIRST(&backing_object->memq); 1462 continue; 1463 } 1464 } 1465 1466 /* 1467 * Busy the page 1468 */ 1469 vm_page_busy(p); 1470 vm_page_unlock_queues(); 1471 1472 KASSERT( 1473 p->object == backing_object, 1474 ("vm_object_qcollapse(): object mismatch") 1475 ); 1476 1477 /* 1478 * Destroy any associated swap 1479 */ 1480 if (backing_object->type == OBJT_SWAP) { 1481 swap_pager_freespace( 1482 backing_object, 1483 p->pindex, 1484 1 1485 ); 1486 } 1487 1488 if ( 1489 p->pindex < backing_offset_index || 1490 new_pindex >= object->size 1491 ) { 1492 /* 1493 * Page is out of the parent object's range, we 1494 * can simply destroy it. 1495 */ 1496 vm_page_lock_queues(); 1497 pmap_remove_all(p); 1498 vm_page_free(p); 1499 vm_page_unlock_queues(); 1500 p = next; 1501 continue; 1502 } 1503 1504 pp = vm_page_lookup(object, new_pindex); 1505 if ( 1506 pp != NULL || 1507 vm_pager_has_page(object, new_pindex, NULL, NULL) 1508 ) { 1509 /* 1510 * page already exists in parent OR swap exists 1511 * for this location in the parent. Destroy 1512 * the original page from the backing object. 1513 * 1514 * Leave the parent's page alone 1515 */ 1516 vm_page_lock_queues(); 1517 pmap_remove_all(p); 1518 vm_page_free(p); 1519 vm_page_unlock_queues(); 1520 p = next; 1521 continue; 1522 } 1523 1524 /* 1525 * Page does not exist in parent, rename the 1526 * page from the backing object to the main object. 1527 * 1528 * If the page was mapped to a process, it can remain 1529 * mapped through the rename. 1530 */ 1531 vm_page_lock_queues(); 1532 vm_page_rename(p, object, new_pindex); 1533 vm_page_unlock_queues(); 1534 /* page automatically made dirty by rename */ 1535 } 1536 p = next; 1537 } 1538 return (r); 1539} 1540 1541 1542/* 1543 * this version of collapse allows the operation to occur earlier and 1544 * when paging_in_progress is true for an object... This is not a complete 1545 * operation, but should plug 99.9% of the rest of the leaks. 1546 */ 1547static void 1548vm_object_qcollapse(vm_object_t object) 1549{ 1550 vm_object_t backing_object = object->backing_object; 1551 1552 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1553 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1554 1555 if (backing_object->ref_count != 1) 1556 return; 1557 1558 backing_object->ref_count += 2; 1559 1560 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1561 1562 backing_object->ref_count -= 2; 1563} 1564 1565/* 1566 * vm_object_collapse: 1567 * 1568 * Collapse an object with the object backing it. 1569 * Pages in the backing object are moved into the 1570 * parent, and the backing object is deallocated. 1571 */ 1572void 1573vm_object_collapse(vm_object_t object) 1574{ 1575 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1576 1577 while (TRUE) { 1578 vm_object_t backing_object; 1579 1580 /* 1581 * Verify that the conditions are right for collapse: 1582 * 1583 * The object exists and the backing object exists. 1584 */ 1585 if ((backing_object = object->backing_object) == NULL) 1586 break; 1587 1588 /* 1589 * we check the backing object first, because it is most likely 1590 * not collapsable. 1591 */ 1592 VM_OBJECT_LOCK(backing_object); 1593 if (backing_object->handle != NULL || 1594 (backing_object->type != OBJT_DEFAULT && 1595 backing_object->type != OBJT_SWAP) || 1596 (backing_object->flags & OBJ_DEAD) || 1597 object->handle != NULL || 1598 (object->type != OBJT_DEFAULT && 1599 object->type != OBJT_SWAP) || 1600 (object->flags & OBJ_DEAD)) { 1601 VM_OBJECT_UNLOCK(backing_object); 1602 break; 1603 } 1604 1605 if ( 1606 object->paging_in_progress != 0 || 1607 backing_object->paging_in_progress != 0 1608 ) { 1609 vm_object_qcollapse(object); 1610 VM_OBJECT_UNLOCK(backing_object); 1611 break; 1612 } 1613 /* 1614 * We know that we can either collapse the backing object (if 1615 * the parent is the only reference to it) or (perhaps) have 1616 * the parent bypass the object if the parent happens to shadow 1617 * all the resident pages in the entire backing object. 1618 * 1619 * This is ignoring pager-backed pages such as swap pages. 1620 * vm_object_backing_scan fails the shadowing test in this 1621 * case. 1622 */ 1623 if (backing_object->ref_count == 1) { 1624 /* 1625 * If there is exactly one reference to the backing 1626 * object, we can collapse it into the parent. 1627 */ 1628 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1629 1630 /* 1631 * Move the pager from backing_object to object. 1632 */ 1633 if (backing_object->type == OBJT_SWAP) { 1634 /* 1635 * swap_pager_copy() can sleep, in which case 1636 * the backing_object's and object's locks are 1637 * released and reacquired. 1638 */ 1639 swap_pager_copy( 1640 backing_object, 1641 object, 1642 OFF_TO_IDX(object->backing_object_offset), TRUE); 1643 } 1644 /* 1645 * Object now shadows whatever backing_object did. 1646 * Note that the reference to 1647 * backing_object->backing_object moves from within 1648 * backing_object to within object. 1649 */ 1650 LIST_REMOVE(object, shadow_list); 1651 backing_object->shadow_count--; 1652 backing_object->generation++; 1653 if (backing_object->backing_object) { 1654 VM_OBJECT_LOCK(backing_object->backing_object); 1655 LIST_REMOVE(backing_object, shadow_list); 1656 LIST_INSERT_HEAD( 1657 &backing_object->backing_object->shadow_head, 1658 object, shadow_list); 1659 /* 1660 * The shadow_count has not changed. 1661 */ 1662 backing_object->backing_object->generation++; 1663 VM_OBJECT_UNLOCK(backing_object->backing_object); 1664 } 1665 object->backing_object = backing_object->backing_object; 1666 object->backing_object_offset += 1667 backing_object->backing_object_offset; 1668 1669 /* 1670 * Discard backing_object. 1671 * 1672 * Since the backing object has no pages, no pager left, 1673 * and no object references within it, all that is 1674 * necessary is to dispose of it. 1675 */ 1676 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1677 VM_OBJECT_UNLOCK(backing_object); 1678 1679 mtx_lock(&vm_object_list_mtx); 1680 TAILQ_REMOVE( 1681 &vm_object_list, 1682 backing_object, 1683 object_list 1684 ); 1685 mtx_unlock(&vm_object_list_mtx); 1686 1687 uma_zfree(obj_zone, backing_object); 1688 1689 object_collapses++; 1690 } else { 1691 vm_object_t new_backing_object; 1692 1693 /* 1694 * If we do not entirely shadow the backing object, 1695 * there is nothing we can do so we give up. 1696 */ 1697 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1698 VM_OBJECT_UNLOCK(backing_object); 1699 break; 1700 } 1701 1702 /* 1703 * Make the parent shadow the next object in the 1704 * chain. Deallocating backing_object will not remove 1705 * it, since its reference count is at least 2. 1706 */ 1707 LIST_REMOVE(object, shadow_list); 1708 backing_object->shadow_count--; 1709 backing_object->generation++; 1710 1711 new_backing_object = backing_object->backing_object; 1712 if ((object->backing_object = new_backing_object) != NULL) { 1713 VM_OBJECT_LOCK(new_backing_object); 1714 LIST_INSERT_HEAD( 1715 &new_backing_object->shadow_head, 1716 object, 1717 shadow_list 1718 ); 1719 new_backing_object->shadow_count++; 1720 new_backing_object->generation++; 1721 vm_object_reference_locked(new_backing_object); 1722 VM_OBJECT_UNLOCK(new_backing_object); 1723 object->backing_object_offset += 1724 backing_object->backing_object_offset; 1725 } 1726 1727 /* 1728 * Drop the reference count on backing_object. Since 1729 * its ref_count was at least 2, it will not vanish. 1730 */ 1731 backing_object->ref_count--; 1732 VM_OBJECT_UNLOCK(backing_object); 1733 object_bypasses++; 1734 } 1735 1736 /* 1737 * Try again with this object's new backing object. 1738 */ 1739 } 1740} 1741 1742/* 1743 * vm_object_page_remove: 1744 * 1745 * Removes all physical pages in the given range from the 1746 * object's list of pages. If the range's end is zero, all 1747 * physical pages from the range's start to the end of the object 1748 * are deleted. 1749 * 1750 * The object must be locked. 1751 */ 1752void 1753vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1754 boolean_t clean_only) 1755{ 1756 vm_page_t p, next; 1757 1758 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1759 if (object->resident_page_count == 0) 1760 return; 1761 1762 /* 1763 * Since physically-backed objects do not use managed pages, we can't 1764 * remove pages from the object (we must instead remove the page 1765 * references, and then destroy the object). 1766 */ 1767 KASSERT(object->type != OBJT_PHYS, 1768 ("attempt to remove pages from a physical object")); 1769 1770 vm_object_pip_add(object, 1); 1771again: 1772 vm_page_lock_queues(); 1773 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1774 if (p->pindex < start) { 1775 p = vm_page_splay(start, object->root); 1776 if ((object->root = p)->pindex < start) 1777 p = TAILQ_NEXT(p, listq); 1778 } 1779 } 1780 /* 1781 * Assert: the variable p is either (1) the page with the 1782 * least pindex greater than or equal to the parameter pindex 1783 * or (2) NULL. 1784 */ 1785 for (; 1786 p != NULL && (p->pindex < end || end == 0); 1787 p = next) { 1788 next = TAILQ_NEXT(p, listq); 1789 1790 if (p->wire_count != 0) { 1791 pmap_remove_all(p); 1792 if (!clean_only) 1793 p->valid = 0; 1794 continue; 1795 } 1796 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1797 goto again; 1798 if (clean_only && p->valid) { 1799 pmap_page_protect(p, VM_PROT_READ | VM_PROT_EXECUTE); 1800 if (p->valid & p->dirty) 1801 continue; 1802 } 1803 pmap_remove_all(p); 1804 vm_page_free(p); 1805 } 1806 vm_page_unlock_queues(); 1807 vm_object_pip_wakeup(object); 1808} 1809 1810/* 1811 * Routine: vm_object_coalesce 1812 * Function: Coalesces two objects backing up adjoining 1813 * regions of memory into a single object. 1814 * 1815 * returns TRUE if objects were combined. 1816 * 1817 * NOTE: Only works at the moment if the second object is NULL - 1818 * if it's not, which object do we lock first? 1819 * 1820 * Parameters: 1821 * prev_object First object to coalesce 1822 * prev_offset Offset into prev_object 1823 * prev_size Size of reference to prev_object 1824 * next_size Size of reference to the second object 1825 * 1826 * Conditions: 1827 * The object must *not* be locked. 1828 */ 1829boolean_t 1830vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 1831 vm_size_t prev_size, vm_size_t next_size) 1832{ 1833 vm_pindex_t next_pindex; 1834 1835 if (prev_object == NULL) 1836 return (TRUE); 1837 VM_OBJECT_LOCK(prev_object); 1838 if (prev_object->type != OBJT_DEFAULT && 1839 prev_object->type != OBJT_SWAP) { 1840 VM_OBJECT_UNLOCK(prev_object); 1841 return (FALSE); 1842 } 1843 1844 /* 1845 * Try to collapse the object first 1846 */ 1847 vm_object_collapse(prev_object); 1848 1849 /* 1850 * Can't coalesce if: . more than one reference . paged out . shadows 1851 * another object . has a copy elsewhere (any of which mean that the 1852 * pages not mapped to prev_entry may be in use anyway) 1853 */ 1854 if (prev_object->backing_object != NULL) { 1855 VM_OBJECT_UNLOCK(prev_object); 1856 return (FALSE); 1857 } 1858 1859 prev_size >>= PAGE_SHIFT; 1860 next_size >>= PAGE_SHIFT; 1861 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 1862 1863 if ((prev_object->ref_count > 1) && 1864 (prev_object->size != next_pindex)) { 1865 VM_OBJECT_UNLOCK(prev_object); 1866 return (FALSE); 1867 } 1868 1869 /* 1870 * Remove any pages that may still be in the object from a previous 1871 * deallocation. 1872 */ 1873 if (next_pindex < prev_object->size) { 1874 vm_object_page_remove(prev_object, 1875 next_pindex, 1876 next_pindex + next_size, FALSE); 1877 if (prev_object->type == OBJT_SWAP) 1878 swap_pager_freespace(prev_object, 1879 next_pindex, next_size); 1880 } 1881 1882 /* 1883 * Extend the object if necessary. 1884 */ 1885 if (next_pindex + next_size > prev_object->size) 1886 prev_object->size = next_pindex + next_size; 1887 1888 VM_OBJECT_UNLOCK(prev_object); 1889 return (TRUE); 1890} 1891 1892void 1893vm_object_set_writeable_dirty(vm_object_t object) 1894{ 1895 struct vnode *vp; 1896 1897 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1898 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1899 if (object->type == OBJT_VNODE && 1900 (vp = (struct vnode *)object->handle) != NULL) { 1901 VI_LOCK(vp); 1902 if ((vp->v_iflag & VI_OBJDIRTY) == 0) 1903 vp->v_iflag |= VI_OBJDIRTY; 1904 VI_UNLOCK(vp); 1905 } 1906} 1907 1908#include "opt_ddb.h" 1909#ifdef DDB 1910#include <sys/kernel.h> 1911 1912#include <sys/cons.h> 1913 1914#include <ddb/ddb.h> 1915 1916static int 1917_vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1918{ 1919 vm_map_t tmpm; 1920 vm_map_entry_t tmpe; 1921 vm_object_t obj; 1922 int entcount; 1923 1924 if (map == 0) 1925 return 0; 1926 1927 if (entry == 0) { 1928 tmpe = map->header.next; 1929 entcount = map->nentries; 1930 while (entcount-- && (tmpe != &map->header)) { 1931 if (_vm_object_in_map(map, object, tmpe)) { 1932 return 1; 1933 } 1934 tmpe = tmpe->next; 1935 } 1936 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1937 tmpm = entry->object.sub_map; 1938 tmpe = tmpm->header.next; 1939 entcount = tmpm->nentries; 1940 while (entcount-- && tmpe != &tmpm->header) { 1941 if (_vm_object_in_map(tmpm, object, tmpe)) { 1942 return 1; 1943 } 1944 tmpe = tmpe->next; 1945 } 1946 } else if ((obj = entry->object.vm_object) != NULL) { 1947 for (; obj; obj = obj->backing_object) 1948 if (obj == object) { 1949 return 1; 1950 } 1951 } 1952 return 0; 1953} 1954 1955static int 1956vm_object_in_map(vm_object_t object) 1957{ 1958 struct proc *p; 1959 1960 /* sx_slock(&allproc_lock); */ 1961 LIST_FOREACH(p, &allproc, p_list) { 1962 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1963 continue; 1964 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 1965 /* sx_sunlock(&allproc_lock); */ 1966 return 1; 1967 } 1968 } 1969 /* sx_sunlock(&allproc_lock); */ 1970 if (_vm_object_in_map(kernel_map, object, 0)) 1971 return 1; 1972 if (_vm_object_in_map(kmem_map, object, 0)) 1973 return 1; 1974 if (_vm_object_in_map(pager_map, object, 0)) 1975 return 1; 1976 if (_vm_object_in_map(buffer_map, object, 0)) 1977 return 1; 1978 return 0; 1979} 1980 1981DB_SHOW_COMMAND(vmochk, vm_object_check) 1982{ 1983 vm_object_t object; 1984 1985 /* 1986 * make sure that internal objs are in a map somewhere 1987 * and none have zero ref counts. 1988 */ 1989 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1990 if (object->handle == NULL && 1991 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1992 if (object->ref_count == 0) { 1993 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1994 (long)object->size); 1995 } 1996 if (!vm_object_in_map(object)) { 1997 db_printf( 1998 "vmochk: internal obj is not in a map: " 1999 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2000 object->ref_count, (u_long)object->size, 2001 (u_long)object->size, 2002 (void *)object->backing_object); 2003 } 2004 } 2005 } 2006} 2007 2008/* 2009 * vm_object_print: [ debug ] 2010 */ 2011DB_SHOW_COMMAND(object, vm_object_print_static) 2012{ 2013 /* XXX convert args. */ 2014 vm_object_t object = (vm_object_t)addr; 2015 boolean_t full = have_addr; 2016 2017 vm_page_t p; 2018 2019 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2020#define count was_count 2021 2022 int count; 2023 2024 if (object == NULL) 2025 return; 2026 2027 db_iprintf( 2028 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n", 2029 object, (int)object->type, (uintmax_t)object->size, 2030 object->resident_page_count, object->ref_count, object->flags); 2031 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2032 object->shadow_count, 2033 object->backing_object ? object->backing_object->ref_count : 0, 2034 object->backing_object, (uintmax_t)object->backing_object_offset); 2035 2036 if (!full) 2037 return; 2038 2039 db_indent += 2; 2040 count = 0; 2041 TAILQ_FOREACH(p, &object->memq, listq) { 2042 if (count == 0) 2043 db_iprintf("memory:="); 2044 else if (count == 6) { 2045 db_printf("\n"); 2046 db_iprintf(" ..."); 2047 count = 0; 2048 } else 2049 db_printf(","); 2050 count++; 2051 2052 db_printf("(off=0x%jx,page=0x%jx)", 2053 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2054 } 2055 if (count != 0) 2056 db_printf("\n"); 2057 db_indent -= 2; 2058} 2059 2060/* XXX. */ 2061#undef count 2062 2063/* XXX need this non-static entry for calling from vm_map_print. */ 2064void 2065vm_object_print( 2066 /* db_expr_t */ long addr, 2067 boolean_t have_addr, 2068 /* db_expr_t */ long count, 2069 char *modif) 2070{ 2071 vm_object_print_static(addr, have_addr, count, modif); 2072} 2073 2074DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2075{ 2076 vm_object_t object; 2077 int nl = 0; 2078 int c; 2079 2080 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2081 vm_pindex_t idx, fidx; 2082 vm_pindex_t osize; 2083 vm_paddr_t pa = -1, padiff; 2084 int rcount; 2085 vm_page_t m; 2086 2087 db_printf("new object: %p\n", (void *)object); 2088 if (nl > 18) { 2089 c = cngetc(); 2090 if (c != ' ') 2091 return; 2092 nl = 0; 2093 } 2094 nl++; 2095 rcount = 0; 2096 fidx = 0; 2097 osize = object->size; 2098 if (osize > 128) 2099 osize = 128; 2100 for (idx = 0; idx < osize; idx++) { 2101 m = vm_page_lookup(object, idx); 2102 if (m == NULL) { 2103 if (rcount) { 2104 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2105 (long)fidx, rcount, (long)pa); 2106 if (nl > 18) { 2107 c = cngetc(); 2108 if (c != ' ') 2109 return; 2110 nl = 0; 2111 } 2112 nl++; 2113 rcount = 0; 2114 } 2115 continue; 2116 } 2117 2118 2119 if (rcount && 2120 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2121 ++rcount; 2122 continue; 2123 } 2124 if (rcount) { 2125 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 2126 padiff >>= PAGE_SHIFT; 2127 padiff &= PQ_L2_MASK; 2128 if (padiff == 0) { 2129 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 2130 ++rcount; 2131 continue; 2132 } 2133 db_printf(" index(%ld)run(%d)pa(0x%lx)", 2134 (long)fidx, rcount, (long)pa); 2135 db_printf("pd(%ld)\n", (long)padiff); 2136 if (nl > 18) { 2137 c = cngetc(); 2138 if (c != ' ') 2139 return; 2140 nl = 0; 2141 } 2142 nl++; 2143 } 2144 fidx = idx; 2145 pa = VM_PAGE_TO_PHYS(m); 2146 rcount = 1; 2147 } 2148 if (rcount) { 2149 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2150 (long)fidx, rcount, (long)pa); 2151 if (nl > 18) { 2152 c = cngetc(); 2153 if (c != ' ') 2154 return; 2155 nl = 0; 2156 } 2157 nl++; 2158 } 2159 } 2160} 2161#endif /* DDB */ 2162