1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * The Mach Operating System project at Carnegie-Mellon University. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 33 * 34 * 35 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 36 * All rights reserved. 37 * 38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 39 * 40 * Permission to use, copy, modify and distribute this software and 41 * its documentation is hereby granted, provided that both the copyright 42 * notice and this permission notice appear in all copies of the 43 * software, derivative works or modified versions, and any portions 44 * thereof, and that both notices appear in supporting documentation. 45 * 46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 49 * 50 * Carnegie Mellon requests users of this software to return to 51 * 52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 53 * School of Computer Science 54 * Carnegie Mellon University 55 * Pittsburgh PA 15213-3890 56 * 57 * any improvements or extensions that they make and grant Carnegie the 58 * rights to redistribute these changes. 59 */ 60 61 /* 62 * Virtual memory object module. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 67 68 #include <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 */ 103 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 104 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, 105 CTLFLAG_RW, &msync_flush_flags, 0, ""); 106 107 static int old_msync; 108 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0, 109 "Use old (insecure) msync behavior"); 110 111 static void vm_object_qcollapse(vm_object_t object); 112 static 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 */ 139 140 struct object_q vm_object_list; 141 struct mtx vm_object_list_mtx; /* lock for object list and count */ 142 143 struct vm_object kernel_object_store; 144 struct vm_object kmem_object_store; 145 146 static long object_collapses; 147 static long object_bypasses; 148 static int next_index; 149 static uma_zone_t obj_zone; 150 #define VM_OBJECTS_INIT 256 151 152 static void vm_object_zinit(void *mem, int size); 153 154 #ifdef INVARIANTS 155 static void vm_object_zdtor(void *mem, int size, void *arg); 156 157 static void 158 vm_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 177 178 static void 179 vm_object_zinit(void *mem, int size) 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 } 192 193 void 194 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object) 195 { 196 int incr; 197 198 TAILQ_INIT(&object->memq); 199 LIST_INIT(&object->shadow_head); 200 201 object->root = NULL; 202 object->type = type; 203 object->size = size; 204 object->generation = 1; 205 object->ref_count = 1; 206 object->flags = 0; 207 if ((object->type == OBJT_DEFAULT) || (object->type == OBJT_SWAP)) 208 object->flags = OBJ_ONEMAPPING; 209 if (size > (PQ_L2_SIZE / 3 + PQ_PRIME1)) 210 incr = PQ_L2_SIZE / 3 + PQ_PRIME1; 211 else 212 incr = size; 213 do 214 object->pg_color = next_index; 215 while (!atomic_cmpset_int(&next_index, object->pg_color, 216 (object->pg_color + incr) & PQ_L2_MASK)); 217 object->handle = NULL; 218 object->backing_object = NULL; 219 object->backing_object_offset = (vm_ooffset_t) 0; 220 221 mtx_lock(&vm_object_list_mtx); 222 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list); 223 mtx_unlock(&vm_object_list_mtx); 224 } 225 226 /* 227 * vm_object_init: 228 * 229 * Initialize the VM objects module. 230 */ 231 void 232 vm_object_init(void) 233 { 234 TAILQ_INIT(&vm_object_list); 235 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF); 236 237 VM_OBJECT_LOCK_INIT(&kernel_object_store, "kernel object"); 238 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 239 kernel_object); 240 241 VM_OBJECT_LOCK_INIT(&kmem_object_store, "kmem object"); 242 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 243 kmem_object); 244 245 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 246 #ifdef INVARIANTS 247 vm_object_zdtor, 248 #else 249 NULL, 250 #endif 251 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 252 uma_prealloc(obj_zone, VM_OBJECTS_INIT); 253 } 254 255 void 256 vm_object_clear_flag(vm_object_t object, u_short bits) 257 { 258 259 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 260 object->flags &= ~bits; 261 } 262 263 void 264 vm_object_pip_add(vm_object_t object, short i) 265 { 266 267 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 268 object->paging_in_progress += i; 269 } 270 271 void 272 vm_object_pip_subtract(vm_object_t object, short i) 273 { 274 275 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 276 object->paging_in_progress -= i; 277 } 278 279 void 280 vm_object_pip_wakeup(vm_object_t object) 281 { 282 283 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 284 object->paging_in_progress--; 285 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 286 vm_object_clear_flag(object, OBJ_PIPWNT); 287 wakeup(object); 288 } 289 } 290 291 void 292 vm_object_pip_wakeupn(vm_object_t object, short i) 293 { 294 295 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 296 if (i) 297 object->paging_in_progress -= i; 298 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 299 vm_object_clear_flag(object, OBJ_PIPWNT); 300 wakeup(object); 301 } 302 } 303 304 void 305 vm_object_pip_wait(vm_object_t object, char *waitid) 306 { 307 308 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 309 while (object->paging_in_progress) { 310 object->flags |= OBJ_PIPWNT; 311 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 312 } 313 } 314 315 /* 316 * vm_object_allocate_wait 317 * 318 * Return a new object with the given size, and give the user the 319 * option of waiting for it to complete or failing if the needed 320 * memory isn't available. 321 */ 322 vm_object_t 323 vm_object_allocate_wait(objtype_t type, vm_pindex_t size, int flags) 324 { 325 vm_object_t result; 326 327 result = (vm_object_t) uma_zalloc(obj_zone, flags); 328 329 if (result != NULL) 330 _vm_object_allocate(type, size, result); 331 332 return (result); 333 } 334 335 /* 336 * vm_object_allocate: 337 * 338 * Returns a new object with the given size. 339 */ 340 vm_object_t 341 vm_object_allocate(objtype_t type, vm_pindex_t size) 342 { 343 return(vm_object_allocate_wait(type, size, M_WAITOK)); 344 } 345 346 347 /* 348 * vm_object_reference: 349 * 350 * Gets another reference to the given object. Note: OBJ_DEAD 351 * objects can be referenced during final cleaning. 352 */ 353 void 354 vm_object_reference(vm_object_t object) 355 { 356 struct vnode *vp; 357 int flags; 358 359 if (object == NULL) 360 return; 361 VM_OBJECT_LOCK(object); 362 object->ref_count++; 363 if (object->type == OBJT_VNODE) { 364 vp = object->handle; 365 VI_LOCK(vp); 366 VM_OBJECT_UNLOCK(object); 367 for (flags = LK_INTERLOCK; vget(vp, flags, curthread); 368 flags = 0) 369 printf("vm_object_reference: delay in vget\n"); 370 } else 371 VM_OBJECT_UNLOCK(object); 372 } 373 374 /* 375 * vm_object_reference_locked: 376 * 377 * Gets another reference to the given object. 378 * 379 * The object must be locked. 380 */ 381 void 382 vm_object_reference_locked(vm_object_t object) 383 { 384 struct vnode *vp; 385 386 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 387 KASSERT((object->flags & OBJ_DEAD) == 0, 388 ("vm_object_reference_locked: dead object referenced")); 389 object->ref_count++; 390 if (object->type == OBJT_VNODE) { 391 vp = object->handle; 392 vref(vp); 393 } 394 } 395 396 /* 397 * Handle deallocating an object of type OBJT_VNODE. 398 */ 399 void 400 vm_object_vndeallocate(vm_object_t object) 401 { 402 struct vnode *vp = (struct vnode *) object->handle; 403 404 GIANT_REQUIRED; 405 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 406 KASSERT(object->type == OBJT_VNODE, 407 ("vm_object_vndeallocate: not a vnode object")); 408 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 409 #ifdef INVARIANTS 410 if (object->ref_count == 0) { 411 vprint("vm_object_vndeallocate", vp); 412 panic("vm_object_vndeallocate: bad object reference count"); 413 } 414 #endif 415 416 object->ref_count--; 417 if (object->ref_count == 0) { 418 mp_fixme("Unlocked vflag access."); 419 vp->v_vflag &= ~VV_TEXT; 420 } 421 VM_OBJECT_UNLOCK(object); 422 /* 423 * vrele may need a vop lock 424 */ 425 vrele(vp); 426 } 427 428 /* 429 * vm_object_deallocate: 430 * 431 * Release a reference to the specified object, 432 * gained either through a vm_object_allocate 433 * or a vm_object_reference call. When all references 434 * are gone, storage associated with this object 435 * may be relinquished. 436 * 437 * No object may be locked. 438 */ 439 void 440 vm_object_deallocate(vm_object_t object) 441 { 442 vm_object_t temp; 443 444 while (object != NULL) { 445 /* 446 * In general, the object should be locked when working with 447 * its type. In this case, in order to maintain proper lock 448 * ordering, an exception is possible because a vnode-backed 449 * object never changes its type. 450 */ 451 if (object->type == OBJT_VNODE) 452 mtx_lock(&Giant); 453 VM_OBJECT_LOCK(object); 454 if (object->type == OBJT_VNODE) { 455 vm_object_vndeallocate(object); 456 mtx_unlock(&Giant); 457 return; 458 } 459 460 KASSERT(object->ref_count != 0, 461 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 462 463 /* 464 * If the reference count goes to 0 we start calling 465 * vm_object_terminate() on the object chain. 466 * A ref count of 1 may be a special case depending on the 467 * shadow count being 0 or 1. 468 */ 469 object->ref_count--; 470 if (object->ref_count > 1) { 471 VM_OBJECT_UNLOCK(object); 472 return; 473 } else if (object->ref_count == 1) { 474 if (object->shadow_count == 0) { 475 vm_object_set_flag(object, OBJ_ONEMAPPING); 476 } else if ((object->shadow_count == 1) && 477 (object->handle == NULL) && 478 (object->type == OBJT_DEFAULT || 479 object->type == OBJT_SWAP)) { 480 vm_object_t robject; 481 482 robject = LIST_FIRST(&object->shadow_head); 483 KASSERT(robject != NULL, 484 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 485 object->ref_count, 486 object->shadow_count)); 487 if (!VM_OBJECT_TRYLOCK(robject)) { 488 /* 489 * Avoid a potential deadlock. 490 */ 491 object->ref_count++; 492 VM_OBJECT_UNLOCK(object); 493 /* 494 * More likely than not the thread 495 * holding robject's lock has lower 496 * priority than the current thread. 497 * Let the lower priority thread run. 498 */ 499 tsleep(&proc0, PVM, "vmo_de", 1); 500 continue; 501 } 502 if ((robject->handle == NULL) && 503 (robject->type == OBJT_DEFAULT || 504 robject->type == OBJT_SWAP)) { 505 506 robject->ref_count++; 507 retry: 508 if (robject->paging_in_progress) { 509 VM_OBJECT_UNLOCK(object); 510 vm_object_pip_wait(robject, 511 "objde1"); 512 VM_OBJECT_LOCK(object); 513 goto retry; 514 } else if (object->paging_in_progress) { 515 VM_OBJECT_UNLOCK(robject); 516 object->flags |= OBJ_PIPWNT; 517 msleep(object, 518 VM_OBJECT_MTX(object), 519 PDROP | PVM, "objde2", 0); 520 VM_OBJECT_LOCK(robject); 521 VM_OBJECT_LOCK(object); 522 goto retry; 523 } 524 VM_OBJECT_UNLOCK(object); 525 if (robject->ref_count == 1) { 526 robject->ref_count--; 527 object = robject; 528 goto doterm; 529 } 530 object = robject; 531 vm_object_collapse(object); 532 VM_OBJECT_UNLOCK(object); 533 continue; 534 } 535 VM_OBJECT_UNLOCK(robject); 536 } 537 VM_OBJECT_UNLOCK(object); 538 return; 539 } 540 doterm: 541 temp = object->backing_object; 542 if (temp != NULL) { 543 VM_OBJECT_LOCK(temp); 544 LIST_REMOVE(object, shadow_list); 545 temp->shadow_count--; 546 temp->generation++; 547 VM_OBJECT_UNLOCK(temp); 548 object->backing_object = NULL; 549 } 550 /* 551 * Don't double-terminate, we could be in a termination 552 * recursion due to the terminate having to sync data 553 * to disk. 554 */ 555 if ((object->flags & OBJ_DEAD) == 0) 556 vm_object_terminate(object); 557 else 558 VM_OBJECT_UNLOCK(object); 559 object = temp; 560 } 561 } 562 563 /* 564 * vm_object_terminate actually destroys the specified object, freeing 565 * up all previously used resources. 566 * 567 * The object must be locked. 568 * This routine may block. 569 */ 570 void 571 vm_object_terminate(vm_object_t object) 572 { 573 vm_page_t p; 574 575 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 576 577 /* 578 * Make sure no one uses us. 579 */ 580 vm_object_set_flag(object, OBJ_DEAD); 581 582 /* 583 * wait for the pageout daemon to be done with the object 584 */ 585 vm_object_pip_wait(object, "objtrm"); 586 587 KASSERT(!object->paging_in_progress, 588 ("vm_object_terminate: pageout in progress")); 589 590 /* 591 * Clean and free the pages, as appropriate. All references to the 592 * object are gone, so we don't need to lock it. 593 */ 594 if (object->type == OBJT_VNODE) { 595 struct vnode *vp = (struct vnode *)object->handle; 596 597 /* 598 * Clean pages and flush buffers. 599 */ 600 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 601 VM_OBJECT_UNLOCK(object); 602 603 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 604 605 VM_OBJECT_LOCK(object); 606 } 607 608 KASSERT(object->ref_count == 0, 609 ("vm_object_terminate: object with references, ref_count=%d", 610 object->ref_count)); 611 612 /* 613 * Now free any remaining pages. For internal objects, this also 614 * removes them from paging queues. Don't free wired pages, just 615 * remove them from the object. 616 */ 617 vm_page_lock_queues(); 618 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 619 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0, 620 ("vm_object_terminate: freeing busy page %p " 621 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags)); 622 if (p->wire_count == 0) { 623 vm_page_busy(p); 624 vm_page_free(p); 625 cnt.v_pfree++; 626 } else { 627 vm_page_busy(p); 628 vm_page_remove(p); 629 } 630 } 631 vm_page_unlock_queues(); 632 633 /* 634 * Let the pager know object is dead. 635 */ 636 vm_pager_deallocate(object); 637 VM_OBJECT_UNLOCK(object); 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 wakeup(object); 647 648 /* 649 * Free the space for the object. 650 */ 651 uma_zfree(obj_zone, object); 652 } 653 654 /* 655 * vm_object_page_clean 656 * 657 * Clean all dirty pages in the specified range of object. Leaves page 658 * on whatever queue it is currently on. If NOSYNC is set then do not 659 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 660 * leaving the object dirty. 661 * 662 * When stuffing pages asynchronously, allow clustering. XXX we need a 663 * synchronous clustering mode implementation. 664 * 665 * Odd semantics: if start == end, we clean everything. 666 * 667 * The object must be locked. 668 */ 669 void 670 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 671 { 672 vm_page_t p, np; 673 vm_pindex_t tstart, tend; 674 vm_pindex_t pi; 675 int clearobjflags; 676 int pagerflags; 677 int curgeneration; 678 679 GIANT_REQUIRED; 680 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 681 if (object->type != OBJT_VNODE || 682 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 683 return; 684 685 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 686 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 687 688 vm_object_set_flag(object, OBJ_CLEANING); 689 690 tstart = start; 691 if (end == 0) { 692 tend = object->size; 693 } else { 694 tend = end; 695 } 696 697 vm_page_lock_queues(); 698 /* 699 * If the caller is smart and only msync()s a range he knows is 700 * dirty, we may be able to avoid an object scan. This results in 701 * a phenominal improvement in performance. We cannot do this 702 * as a matter of course because the object may be huge - e.g. 703 * the size might be in the gigabytes or terrabytes. 704 */ 705 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 706 vm_pindex_t tscan; 707 int scanlimit; 708 int scanreset; 709 710 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 711 if (scanreset < 16) 712 scanreset = 16; 713 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 714 715 scanlimit = scanreset; 716 tscan = tstart; 717 while (tscan < tend) { 718 curgeneration = object->generation; 719 p = vm_page_lookup(object, tscan); 720 if (p == NULL || p->valid == 0 || 721 (p->queue - p->pc) == PQ_CACHE) { 722 if (--scanlimit == 0) 723 break; 724 ++tscan; 725 continue; 726 } 727 vm_page_test_dirty(p); 728 if ((p->dirty & p->valid) == 0) { 729 if (--scanlimit == 0) 730 break; 731 ++tscan; 732 continue; 733 } 734 /* 735 * If we have been asked to skip nosync pages and 736 * this is a nosync page, we can't continue. 737 */ 738 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 739 if (--scanlimit == 0) 740 break; 741 ++tscan; 742 continue; 743 } 744 scanlimit = scanreset; 745 746 /* 747 * This returns 0 if it was unable to busy the first 748 * page (i.e. had to sleep). 749 */ 750 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 751 } 752 753 /* 754 * If everything was dirty and we flushed it successfully, 755 * and the requested range is not the entire object, we 756 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 757 * return immediately. 758 */ 759 if (tscan >= tend && (tstart || tend < object->size)) { 760 vm_page_unlock_queues(); 761 vm_object_clear_flag(object, OBJ_CLEANING); 762 return; 763 } 764 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 765 } 766 767 /* 768 * Generally set CLEANCHK interlock and make the page read-only so 769 * we can then clear the object flags. 770 * 771 * However, if this is a nosync mmap then the object is likely to 772 * stay dirty so do not mess with the page and do not clear the 773 * object flags. 774 */ 775 clearobjflags = 1; 776 TAILQ_FOREACH(p, &object->memq, listq) { 777 vm_page_flag_set(p, PG_CLEANCHK); 778 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 779 clearobjflags = 0; 780 else 781 pmap_page_protect(p, VM_PROT_READ); 782 } 783 784 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 785 struct vnode *vp; 786 787 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 788 if (object->type == OBJT_VNODE && 789 (vp = (struct vnode *)object->handle) != NULL) { 790 VI_LOCK(vp); 791 if (vp->v_iflag & VI_OBJDIRTY) 792 vp->v_iflag &= ~VI_OBJDIRTY; 793 VI_UNLOCK(vp); 794 } 795 } 796 797 rescan: 798 curgeneration = object->generation; 799 800 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 801 int n; 802 803 np = TAILQ_NEXT(p, listq); 804 805 again: 806 pi = p->pindex; 807 if (((p->flags & PG_CLEANCHK) == 0) || 808 (pi < tstart) || (pi >= tend) || 809 (p->valid == 0) || 810 ((p->queue - p->pc) == PQ_CACHE)) { 811 vm_page_flag_clear(p, PG_CLEANCHK); 812 continue; 813 } 814 815 vm_page_test_dirty(p); 816 if ((p->dirty & p->valid) == 0) { 817 vm_page_flag_clear(p, PG_CLEANCHK); 818 continue; 819 } 820 821 /* 822 * If we have been asked to skip nosync pages and this is a 823 * nosync page, skip it. Note that the object flags were 824 * not cleared in this case so we do not have to set them. 825 */ 826 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 827 vm_page_flag_clear(p, PG_CLEANCHK); 828 continue; 829 } 830 831 n = vm_object_page_collect_flush(object, p, 832 curgeneration, pagerflags); 833 if (n == 0) 834 goto rescan; 835 836 if (object->generation != curgeneration) 837 goto rescan; 838 839 /* 840 * Try to optimize the next page. If we can't we pick up 841 * our (random) scan where we left off. 842 */ 843 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 844 if ((p = vm_page_lookup(object, pi + n)) != NULL) 845 goto again; 846 } 847 } 848 vm_page_unlock_queues(); 849 #if 0 850 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 851 #endif 852 853 vm_object_clear_flag(object, OBJ_CLEANING); 854 return; 855 } 856 857 static int 858 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 859 { 860 int runlen; 861 int maxf; 862 int chkb; 863 int maxb; 864 int i; 865 vm_pindex_t pi; 866 vm_page_t maf[vm_pageout_page_count]; 867 vm_page_t mab[vm_pageout_page_count]; 868 vm_page_t ma[vm_pageout_page_count]; 869 870 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 871 pi = p->pindex; 872 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 873 vm_page_lock_queues(); 874 if (object->generation != curgeneration) { 875 return(0); 876 } 877 } 878 maxf = 0; 879 for(i = 1; i < vm_pageout_page_count; i++) { 880 vm_page_t tp; 881 882 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 883 if ((tp->flags & PG_BUSY) || 884 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 885 (tp->flags & PG_CLEANCHK) == 0) || 886 (tp->busy != 0)) 887 break; 888 if((tp->queue - tp->pc) == PQ_CACHE) { 889 vm_page_flag_clear(tp, PG_CLEANCHK); 890 break; 891 } 892 vm_page_test_dirty(tp); 893 if ((tp->dirty & tp->valid) == 0) { 894 vm_page_flag_clear(tp, PG_CLEANCHK); 895 break; 896 } 897 maf[ i - 1 ] = tp; 898 maxf++; 899 continue; 900 } 901 break; 902 } 903 904 maxb = 0; 905 chkb = vm_pageout_page_count - maxf; 906 if (chkb) { 907 for(i = 1; i < chkb;i++) { 908 vm_page_t tp; 909 910 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 911 if ((tp->flags & PG_BUSY) || 912 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 913 (tp->flags & PG_CLEANCHK) == 0) || 914 (tp->busy != 0)) 915 break; 916 if ((tp->queue - tp->pc) == PQ_CACHE) { 917 vm_page_flag_clear(tp, PG_CLEANCHK); 918 break; 919 } 920 vm_page_test_dirty(tp); 921 if ((tp->dirty & tp->valid) == 0) { 922 vm_page_flag_clear(tp, PG_CLEANCHK); 923 break; 924 } 925 mab[ i - 1 ] = tp; 926 maxb++; 927 continue; 928 } 929 break; 930 } 931 } 932 933 for(i = 0; i < maxb; i++) { 934 int index = (maxb - i) - 1; 935 ma[index] = mab[i]; 936 vm_page_flag_clear(ma[index], PG_CLEANCHK); 937 } 938 vm_page_flag_clear(p, PG_CLEANCHK); 939 ma[maxb] = p; 940 for(i = 0; i < maxf; i++) { 941 int index = (maxb + i) + 1; 942 ma[index] = maf[i]; 943 vm_page_flag_clear(ma[index], PG_CLEANCHK); 944 } 945 runlen = maxb + maxf + 1; 946 947 vm_pageout_flush(ma, runlen, pagerflags); 948 for (i = 0; i < runlen; i++) { 949 if (ma[i]->valid & ma[i]->dirty) { 950 pmap_page_protect(ma[i], VM_PROT_READ); 951 vm_page_flag_set(ma[i], PG_CLEANCHK); 952 953 /* 954 * maxf will end up being the actual number of pages 955 * we wrote out contiguously, non-inclusive of the 956 * first page. We do not count look-behind pages. 957 */ 958 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 959 maxf = i - maxb - 1; 960 } 961 } 962 return(maxf + 1); 963 } 964 965 /* 966 * Note that there is absolutely no sense in writing out 967 * anonymous objects, so we track down the vnode object 968 * to write out. 969 * We invalidate (remove) all pages from the address space 970 * for semantic correctness. 971 * 972 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 973 * may start out with a NULL object. 974 */ 975 void 976 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 977 boolean_t syncio, boolean_t invalidate) 978 { 979 vm_object_t backing_object; 980 struct vnode *vp; 981 int flags; 982 983 if (object == NULL) 984 return; 985 VM_OBJECT_LOCK(object); 986 while ((backing_object = object->backing_object) != NULL) { 987 VM_OBJECT_LOCK(backing_object); 988 offset += object->backing_object_offset; 989 VM_OBJECT_UNLOCK(object); 990 object = backing_object; 991 if (object->size < OFF_TO_IDX(offset + size)) 992 size = IDX_TO_OFF(object->size) - offset; 993 } 994 /* 995 * Flush pages if writing is allowed, invalidate them 996 * if invalidation requested. Pages undergoing I/O 997 * will be ignored by vm_object_page_remove(). 998 * 999 * We cannot lock the vnode and then wait for paging 1000 * to complete without deadlocking against vm_fault. 1001 * Instead we simply call vm_object_page_remove() and 1002 * allow it to block internally on a page-by-page 1003 * basis when it encounters pages undergoing async 1004 * I/O. 1005 */ 1006 if (object->type == OBJT_VNODE && 1007 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1008 vp = object->handle; 1009 VM_OBJECT_UNLOCK(object); 1010 mtx_lock(&Giant); 1011 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 1012 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1013 flags |= invalidate ? OBJPC_INVAL : 0; 1014 VM_OBJECT_LOCK(object); 1015 vm_object_page_clean(object, 1016 OFF_TO_IDX(offset), 1017 OFF_TO_IDX(offset + size + PAGE_MASK), 1018 flags); 1019 VM_OBJECT_UNLOCK(object); 1020 VOP_UNLOCK(vp, 0, curthread); 1021 mtx_unlock(&Giant); 1022 VM_OBJECT_LOCK(object); 1023 } 1024 if ((object->type == OBJT_VNODE || 1025 object->type == OBJT_DEVICE) && invalidate) { 1026 boolean_t purge; 1027 purge = old_msync || (object->type == OBJT_DEVICE); 1028 vm_object_page_remove(object, 1029 OFF_TO_IDX(offset), 1030 OFF_TO_IDX(offset + size + PAGE_MASK), 1031 purge ? FALSE : TRUE); 1032 } 1033 VM_OBJECT_UNLOCK(object); 1034 } 1035 1036 /* 1037 * vm_object_madvise: 1038 * 1039 * Implements the madvise function at the object/page level. 1040 * 1041 * MADV_WILLNEED (any object) 1042 * 1043 * Activate the specified pages if they are resident. 1044 * 1045 * MADV_DONTNEED (any object) 1046 * 1047 * Deactivate the specified pages if they are resident. 1048 * 1049 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1050 * OBJ_ONEMAPPING only) 1051 * 1052 * Deactivate and clean the specified pages if they are 1053 * resident. This permits the process to reuse the pages 1054 * without faulting or the kernel to reclaim the pages 1055 * without I/O. 1056 */ 1057 void 1058 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1059 { 1060 vm_pindex_t end, tpindex; 1061 vm_object_t backing_object, tobject; 1062 vm_page_t m; 1063 1064 if (object == NULL) 1065 return; 1066 end = pindex + count; 1067 /* 1068 * Locate and adjust resident pages 1069 */ 1070 for (; pindex < end; pindex += 1) { 1071 relookup: 1072 tobject = object; 1073 tpindex = pindex; 1074 VM_OBJECT_LOCK(tobject); 1075 shadowlookup: 1076 /* 1077 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1078 * and those pages must be OBJ_ONEMAPPING. 1079 */ 1080 if (advise == MADV_FREE) { 1081 if ((tobject->type != OBJT_DEFAULT && 1082 tobject->type != OBJT_SWAP) || 1083 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1084 goto unlock_tobject; 1085 } 1086 } 1087 m = vm_page_lookup(tobject, tpindex); 1088 if (m == NULL) { 1089 /* 1090 * There may be swap even if there is no backing page 1091 */ 1092 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1093 swap_pager_freespace(tobject, tpindex, 1); 1094 /* 1095 * next object 1096 */ 1097 backing_object = tobject->backing_object; 1098 if (backing_object == NULL) 1099 goto unlock_tobject; 1100 VM_OBJECT_LOCK(backing_object); 1101 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 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 (vm_page_sleep_if_busy(m, TRUE, "madvpo")) { 1121 VM_OBJECT_UNLOCK(tobject); 1122 goto relookup; 1123 } 1124 if (advise == MADV_WILLNEED) { 1125 vm_page_activate(m); 1126 } else if (advise == MADV_DONTNEED) { 1127 vm_page_dontneed(m); 1128 } else if (advise == MADV_FREE) { 1129 /* 1130 * Mark the page clean. This will allow the page 1131 * to be freed up by the system. However, such pages 1132 * are often reused quickly by malloc()/free() 1133 * so we do not do anything that would cause 1134 * a page fault if we can help it. 1135 * 1136 * Specifically, we do not try to actually free 1137 * the page now nor do we try to put it in the 1138 * cache (which would cause a page fault on reuse). 1139 * 1140 * But we do make the page is freeable as we 1141 * can without actually taking the step of unmapping 1142 * it. 1143 */ 1144 pmap_clear_modify(m); 1145 m->dirty = 0; 1146 m->act_count = 0; 1147 vm_page_dontneed(m); 1148 } 1149 vm_page_unlock_queues(); 1150 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1151 swap_pager_freespace(tobject, tpindex, 1); 1152 unlock_tobject: 1153 VM_OBJECT_UNLOCK(tobject); 1154 } 1155 } 1156 1157 /* 1158 * vm_object_shadow: 1159 * 1160 * Create a new object which is backed by the 1161 * specified existing object range. The source 1162 * object reference is deallocated. 1163 * 1164 * The new object and offset into that object 1165 * are returned in the source parameters. 1166 */ 1167 void 1168 vm_object_shadow( 1169 vm_object_t *object, /* IN/OUT */ 1170 vm_ooffset_t *offset, /* IN/OUT */ 1171 vm_size_t length) 1172 { 1173 vm_object_t source; 1174 vm_object_t result; 1175 1176 source = *object; 1177 1178 /* 1179 * Don't create the new object if the old object isn't shared. 1180 */ 1181 if (source != NULL) { 1182 VM_OBJECT_LOCK(source); 1183 if (source->ref_count == 1 && 1184 source->handle == NULL && 1185 (source->type == OBJT_DEFAULT || 1186 source->type == OBJT_SWAP)) { 1187 VM_OBJECT_UNLOCK(source); 1188 return; 1189 } 1190 VM_OBJECT_UNLOCK(source); 1191 } 1192 1193 /* 1194 * Allocate a new object with the given length. 1195 */ 1196 result = vm_object_allocate(OBJT_DEFAULT, length); 1197 1198 /* 1199 * The new object shadows the source object, adding a reference to it. 1200 * Our caller changes his reference to point to the new object, 1201 * removing a reference to the source object. Net result: no change 1202 * of reference count. 1203 * 1204 * Try to optimize the result object's page color when shadowing 1205 * in order to maintain page coloring consistency in the combined 1206 * shadowed object. 1207 */ 1208 result->backing_object = source; 1209 /* 1210 * Store the offset into the source object, and fix up the offset into 1211 * the new object. 1212 */ 1213 result->backing_object_offset = *offset; 1214 if (source != NULL) { 1215 VM_OBJECT_LOCK(source); 1216 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1217 source->shadow_count++; 1218 source->generation++; 1219 if (length < source->size) 1220 length = source->size; 1221 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 || 1222 source->generation > 1) 1223 length = PQ_L2_SIZE / 3 + PQ_PRIME1; 1224 result->pg_color = (source->pg_color + 1225 length * source->generation) & PQ_L2_MASK; 1226 VM_OBJECT_UNLOCK(source); 1227 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & 1228 PQ_L2_MASK; 1229 } 1230 1231 1232 /* 1233 * Return the new things 1234 */ 1235 *offset = 0; 1236 *object = result; 1237 } 1238 1239 /* 1240 * vm_object_split: 1241 * 1242 * Split the pages in a map entry into a new object. This affords 1243 * easier removal of unused pages, and keeps object inheritance from 1244 * being a negative impact on memory usage. 1245 */ 1246 void 1247 vm_object_split(vm_map_entry_t entry) 1248 { 1249 vm_page_t m; 1250 vm_object_t orig_object, new_object, source; 1251 vm_pindex_t offidxstart, offidxend; 1252 vm_size_t idx, size; 1253 1254 orig_object = entry->object.vm_object; 1255 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1256 return; 1257 if (orig_object->ref_count <= 1) 1258 return; 1259 VM_OBJECT_UNLOCK(orig_object); 1260 1261 offidxstart = OFF_TO_IDX(entry->offset); 1262 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); 1263 size = offidxend - offidxstart; 1264 1265 /* 1266 * If swap_pager_copy() is later called, it will convert new_object 1267 * into a swap object. 1268 */ 1269 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1270 1271 VM_OBJECT_LOCK(new_object); 1272 VM_OBJECT_LOCK(orig_object); 1273 source = orig_object->backing_object; 1274 if (source != NULL) { 1275 VM_OBJECT_LOCK(source); 1276 LIST_INSERT_HEAD(&source->shadow_head, 1277 new_object, shadow_list); 1278 source->shadow_count++; 1279 source->generation++; 1280 vm_object_reference_locked(source); /* for new_object */ 1281 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1282 VM_OBJECT_UNLOCK(source); 1283 new_object->backing_object_offset = 1284 orig_object->backing_object_offset + entry->offset; 1285 new_object->backing_object = source; 1286 } 1287 for (idx = 0; idx < size; idx++) { 1288 retry: 1289 m = vm_page_lookup(orig_object, offidxstart + idx); 1290 if (m == NULL) 1291 continue; 1292 1293 /* 1294 * We must wait for pending I/O to complete before we can 1295 * rename the page. 1296 * 1297 * We do not have to VM_PROT_NONE the page as mappings should 1298 * not be changed by this operation. 1299 */ 1300 vm_page_lock_queues(); 1301 if ((m->flags & PG_BUSY) || m->busy) { 1302 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1303 VM_OBJECT_UNLOCK(orig_object); 1304 VM_OBJECT_UNLOCK(new_object); 1305 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0); 1306 VM_OBJECT_LOCK(new_object); 1307 VM_OBJECT_LOCK(orig_object); 1308 goto retry; 1309 } 1310 vm_page_busy(m); 1311 vm_page_rename(m, new_object, idx); 1312 /* page automatically made dirty by rename and cache handled */ 1313 vm_page_busy(m); 1314 vm_page_unlock_queues(); 1315 } 1316 if (orig_object->type == OBJT_SWAP) { 1317 /* 1318 * swap_pager_copy() can sleep, in which case the orig_object's 1319 * and new_object's locks are released and reacquired. 1320 */ 1321 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1322 } 1323 VM_OBJECT_UNLOCK(orig_object); 1324 vm_page_lock_queues(); 1325 TAILQ_FOREACH(m, &new_object->memq, listq) 1326 vm_page_wakeup(m); 1327 vm_page_unlock_queues(); 1328 VM_OBJECT_UNLOCK(new_object); 1329 entry->object.vm_object = new_object; 1330 entry->offset = 0LL; 1331 vm_object_deallocate(orig_object); 1332 VM_OBJECT_LOCK(new_object); 1333 } 1334 1335 #define OBSC_TEST_ALL_SHADOWED 0x0001 1336 #define OBSC_COLLAPSE_NOWAIT 0x0002 1337 #define OBSC_COLLAPSE_WAIT 0x0004 1338 1339 static int 1340 vm_object_backing_scan(vm_object_t object, int op) 1341 { 1342 int r = 1; 1343 vm_page_t p; 1344 vm_object_t backing_object; 1345 vm_pindex_t backing_offset_index; 1346 1347 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1348 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1349 1350 backing_object = object->backing_object; 1351 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1352 1353 /* 1354 * Initial conditions 1355 */ 1356 if (op & OBSC_TEST_ALL_SHADOWED) { 1357 /* 1358 * We do not want to have to test for the existence of 1359 * swap pages in the backing object. XXX but with the 1360 * new swapper this would be pretty easy to do. 1361 * 1362 * XXX what about anonymous MAP_SHARED memory that hasn't 1363 * been ZFOD faulted yet? If we do not test for this, the 1364 * shadow test may succeed! XXX 1365 */ 1366 if (backing_object->type != OBJT_DEFAULT) { 1367 return (0); 1368 } 1369 } 1370 if (op & OBSC_COLLAPSE_WAIT) { 1371 vm_object_set_flag(backing_object, OBJ_DEAD); 1372 } 1373 1374 /* 1375 * Our scan 1376 */ 1377 p = TAILQ_FIRST(&backing_object->memq); 1378 while (p) { 1379 vm_page_t next = TAILQ_NEXT(p, listq); 1380 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1381 1382 if (op & OBSC_TEST_ALL_SHADOWED) { 1383 vm_page_t pp; 1384 1385 /* 1386 * Ignore pages outside the parent object's range 1387 * and outside the parent object's mapping of the 1388 * backing object. 1389 * 1390 * note that we do not busy the backing object's 1391 * page. 1392 */ 1393 if ( 1394 p->pindex < backing_offset_index || 1395 new_pindex >= object->size 1396 ) { 1397 p = next; 1398 continue; 1399 } 1400 1401 /* 1402 * See if the parent has the page or if the parent's 1403 * object pager has the page. If the parent has the 1404 * page but the page is not valid, the parent's 1405 * object pager must have the page. 1406 * 1407 * If this fails, the parent does not completely shadow 1408 * the object and we might as well give up now. 1409 */ 1410 1411 pp = vm_page_lookup(object, new_pindex); 1412 if ( 1413 (pp == NULL || pp->valid == 0) && 1414 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1415 ) { 1416 r = 0; 1417 break; 1418 } 1419 } 1420 1421 /* 1422 * Check for busy page 1423 */ 1424 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1425 vm_page_t pp; 1426 1427 vm_page_lock_queues(); 1428 if (op & OBSC_COLLAPSE_NOWAIT) { 1429 if ((p->flags & PG_BUSY) || 1430 !p->valid || 1431 p->hold_count || 1432 p->wire_count || 1433 p->busy) { 1434 vm_page_unlock_queues(); 1435 p = next; 1436 continue; 1437 } 1438 } else if (op & OBSC_COLLAPSE_WAIT) { 1439 if ((p->flags & PG_BUSY) || p->busy) { 1440 vm_page_flag_set(p, 1441 PG_WANTED | PG_REFERENCED); 1442 VM_OBJECT_UNLOCK(backing_object); 1443 VM_OBJECT_UNLOCK(object); 1444 msleep(p, &vm_page_queue_mtx, 1445 PDROP | PVM, "vmocol", 0); 1446 VM_OBJECT_LOCK(object); 1447 VM_OBJECT_LOCK(backing_object); 1448 /* 1449 * If we slept, anything could have 1450 * happened. Since the object is 1451 * marked dead, the backing offset 1452 * should not have changed so we 1453 * just restart our scan. 1454 */ 1455 p = TAILQ_FIRST(&backing_object->memq); 1456 continue; 1457 } 1458 } 1459 1460 /* 1461 * Busy the page 1462 */ 1463 vm_page_busy(p); 1464 vm_page_unlock_queues(); 1465 1466 KASSERT( 1467 p->object == backing_object, 1468 ("vm_object_qcollapse(): object mismatch") 1469 ); 1470 1471 /* 1472 * Destroy any associated swap 1473 */ 1474 if (backing_object->type == OBJT_SWAP) { 1475 swap_pager_freespace( 1476 backing_object, 1477 p->pindex, 1478 1 1479 ); 1480 } 1481 1482 if ( 1483 p->pindex < backing_offset_index || 1484 new_pindex >= object->size 1485 ) { 1486 /* 1487 * Page is out of the parent object's range, we 1488 * can simply destroy it. 1489 */ 1490 vm_page_lock_queues(); 1491 pmap_remove_all(p); 1492 vm_page_free(p); 1493 vm_page_unlock_queues(); 1494 p = next; 1495 continue; 1496 } 1497 1498 pp = vm_page_lookup(object, new_pindex); 1499 if ( 1500 pp != NULL || 1501 vm_pager_has_page(object, new_pindex, NULL, NULL) 1502 ) { 1503 /* 1504 * page already exists in parent OR swap exists 1505 * for this location in the parent. Destroy 1506 * the original page from the backing object. 1507 * 1508 * Leave the parent's page alone 1509 */ 1510 vm_page_lock_queues(); 1511 pmap_remove_all(p); 1512 vm_page_free(p); 1513 vm_page_unlock_queues(); 1514 p = next; 1515 continue; 1516 } 1517 1518 /* 1519 * Page does not exist in parent, rename the 1520 * page from the backing object to the main object. 1521 * 1522 * If the page was mapped to a process, it can remain 1523 * mapped through the rename. 1524 */ 1525 vm_page_lock_queues(); 1526 vm_page_rename(p, object, new_pindex); 1527 vm_page_unlock_queues(); 1528 /* page automatically made dirty by rename */ 1529 } 1530 p = next; 1531 } 1532 return (r); 1533 } 1534 1535 1536 /* 1537 * this version of collapse allows the operation to occur earlier and 1538 * when paging_in_progress is true for an object... This is not a complete 1539 * operation, but should plug 99.9% of the rest of the leaks. 1540 */ 1541 static void 1542 vm_object_qcollapse(vm_object_t object) 1543 { 1544 vm_object_t backing_object = object->backing_object; 1545 1546 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1547 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1548 1549 if (backing_object->ref_count != 1) 1550 return; 1551 1552 backing_object->ref_count += 2; 1553 1554 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1555 1556 backing_object->ref_count -= 2; 1557 } 1558 1559 /* 1560 * vm_object_collapse: 1561 * 1562 * Collapse an object with the object backing it. 1563 * Pages in the backing object are moved into the 1564 * parent, and the backing object is deallocated. 1565 */ 1566 void 1567 vm_object_collapse(vm_object_t object) 1568 { 1569 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1570 1571 while (TRUE) { 1572 vm_object_t backing_object; 1573 1574 /* 1575 * Verify that the conditions are right for collapse: 1576 * 1577 * The object exists and the backing object exists. 1578 */ 1579 if ((backing_object = object->backing_object) == NULL) 1580 break; 1581 1582 /* 1583 * we check the backing object first, because it is most likely 1584 * not collapsable. 1585 */ 1586 VM_OBJECT_LOCK(backing_object); 1587 if (backing_object->handle != NULL || 1588 (backing_object->type != OBJT_DEFAULT && 1589 backing_object->type != OBJT_SWAP) || 1590 (backing_object->flags & OBJ_DEAD) || 1591 object->handle != NULL || 1592 (object->type != OBJT_DEFAULT && 1593 object->type != OBJT_SWAP) || 1594 (object->flags & OBJ_DEAD)) { 1595 VM_OBJECT_UNLOCK(backing_object); 1596 break; 1597 } 1598 1599 if ( 1600 object->paging_in_progress != 0 || 1601 backing_object->paging_in_progress != 0 1602 ) { 1603 vm_object_qcollapse(object); 1604 VM_OBJECT_UNLOCK(backing_object); 1605 break; 1606 } 1607 /* 1608 * We know that we can either collapse the backing object (if 1609 * the parent is the only reference to it) or (perhaps) have 1610 * the parent bypass the object if the parent happens to shadow 1611 * all the resident pages in the entire backing object. 1612 * 1613 * This is ignoring pager-backed pages such as swap pages. 1614 * vm_object_backing_scan fails the shadowing test in this 1615 * case. 1616 */ 1617 if (backing_object->ref_count == 1) { 1618 /* 1619 * If there is exactly one reference to the backing 1620 * object, we can collapse it into the parent. 1621 */ 1622 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1623 1624 /* 1625 * Move the pager from backing_object to object. 1626 */ 1627 if (backing_object->type == OBJT_SWAP) { 1628 /* 1629 * swap_pager_copy() can sleep, in which case 1630 * the backing_object's and object's locks are 1631 * released and reacquired. 1632 */ 1633 swap_pager_copy( 1634 backing_object, 1635 object, 1636 OFF_TO_IDX(object->backing_object_offset), TRUE); 1637 } 1638 /* 1639 * Object now shadows whatever backing_object did. 1640 * Note that the reference to 1641 * backing_object->backing_object moves from within 1642 * backing_object to within object. 1643 */ 1644 LIST_REMOVE(object, shadow_list); 1645 backing_object->shadow_count--; 1646 backing_object->generation++; 1647 if (backing_object->backing_object) { 1648 VM_OBJECT_LOCK(backing_object->backing_object); 1649 LIST_REMOVE(backing_object, shadow_list); 1650 LIST_INSERT_HEAD( 1651 &backing_object->backing_object->shadow_head, 1652 object, shadow_list); 1653 /* 1654 * The shadow_count has not changed. 1655 */ 1656 backing_object->backing_object->generation++; 1657 VM_OBJECT_UNLOCK(backing_object->backing_object); 1658 } 1659 object->backing_object = backing_object->backing_object; 1660 object->backing_object_offset += 1661 backing_object->backing_object_offset; 1662 1663 /* 1664 * Discard backing_object. 1665 * 1666 * Since the backing object has no pages, no pager left, 1667 * and no object references within it, all that is 1668 * necessary is to dispose of it. 1669 */ 1670 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1671 VM_OBJECT_UNLOCK(backing_object); 1672 1673 mtx_lock(&vm_object_list_mtx); 1674 TAILQ_REMOVE( 1675 &vm_object_list, 1676 backing_object, 1677 object_list 1678 ); 1679 mtx_unlock(&vm_object_list_mtx); 1680 1681 uma_zfree(obj_zone, backing_object); 1682 1683 object_collapses++; 1684 } else { 1685 vm_object_t new_backing_object; 1686 1687 /* 1688 * If we do not entirely shadow the backing object, 1689 * there is nothing we can do so we give up. 1690 */ 1691 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1692 VM_OBJECT_UNLOCK(backing_object); 1693 break; 1694 } 1695 1696 /* 1697 * Make the parent shadow the next object in the 1698 * chain. Deallocating backing_object will not remove 1699 * it, since its reference count is at least 2. 1700 */ 1701 LIST_REMOVE(object, shadow_list); 1702 backing_object->shadow_count--; 1703 backing_object->generation++; 1704 1705 new_backing_object = backing_object->backing_object; 1706 if ((object->backing_object = new_backing_object) != NULL) { 1707 VM_OBJECT_LOCK(new_backing_object); 1708 LIST_INSERT_HEAD( 1709 &new_backing_object->shadow_head, 1710 object, 1711 shadow_list 1712 ); 1713 new_backing_object->shadow_count++; 1714 new_backing_object->generation++; 1715 vm_object_reference_locked(new_backing_object); 1716 VM_OBJECT_UNLOCK(new_backing_object); 1717 object->backing_object_offset += 1718 backing_object->backing_object_offset; 1719 } 1720 1721 /* 1722 * Drop the reference count on backing_object. Since 1723 * its ref_count was at least 2, it will not vanish. 1724 */ 1725 backing_object->ref_count--; 1726 VM_OBJECT_UNLOCK(backing_object); 1727 object_bypasses++; 1728 } 1729 1730 /* 1731 * Try again with this object's new backing object. 1732 */ 1733 } 1734 } 1735 1736 /* 1737 * vm_object_page_remove: 1738 * 1739 * Removes all physical pages in the given range from the 1740 * object's list of pages. If the range's end is zero, all 1741 * physical pages from the range's start to the end of the object 1742 * are deleted. 1743 * 1744 * The object must be locked. 1745 */ 1746 void 1747 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1748 boolean_t clean_only) 1749 { 1750 vm_page_t p, next; 1751 1752 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1753 if (object->resident_page_count == 0) 1754 return; 1755 1756 /* 1757 * Since physically-backed objects do not use managed pages, we can't 1758 * remove pages from the object (we must instead remove the page 1759 * references, and then destroy the object). 1760 */ 1761 KASSERT(object->type != OBJT_PHYS, 1762 ("attempt to remove pages from a physical object")); 1763 1764 vm_object_pip_add(object, 1); 1765 again: 1766 vm_page_lock_queues(); 1767 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1768 if (p->pindex < start) { 1769 p = vm_page_splay(start, object->root); 1770 if ((object->root = p)->pindex < start) 1771 p = TAILQ_NEXT(p, listq); 1772 } 1773 } 1774 /* 1775 * Assert: the variable p is either (1) the page with the 1776 * least pindex greater than or equal to the parameter pindex 1777 * or (2) NULL. 1778 */ 1779 for (; 1780 p != NULL && (p->pindex < end || end == 0); 1781 p = next) { 1782 next = TAILQ_NEXT(p, listq); 1783 1784 if (p->wire_count != 0) { 1785 pmap_remove_all(p); 1786 if (!clean_only) 1787 p->valid = 0; 1788 continue; 1789 } 1790 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1791 goto again; 1792 if (clean_only && p->valid) { 1793 pmap_page_protect(p, VM_PROT_READ | VM_PROT_EXECUTE); 1794 if (p->valid & p->dirty) 1795 continue; 1796 } 1797 vm_page_busy(p); 1798 pmap_remove_all(p); 1799 vm_page_free(p); 1800 } 1801 vm_page_unlock_queues(); 1802 vm_object_pip_wakeup(object); 1803 } 1804 1805 /* 1806 * Routine: vm_object_coalesce 1807 * Function: Coalesces two objects backing up adjoining 1808 * regions of memory into a single object. 1809 * 1810 * returns TRUE if objects were combined. 1811 * 1812 * NOTE: Only works at the moment if the second object is NULL - 1813 * if it's not, which object do we lock first? 1814 * 1815 * Parameters: 1816 * prev_object First object to coalesce 1817 * prev_offset Offset into prev_object 1818 * prev_size Size of reference to prev_object 1819 * next_size Size of reference to the second object 1820 * 1821 * Conditions: 1822 * The object must *not* be locked. 1823 */ 1824 boolean_t 1825 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 1826 vm_size_t prev_size, vm_size_t next_size) 1827 { 1828 vm_pindex_t next_pindex; 1829 1830 if (prev_object == NULL) 1831 return (TRUE); 1832 VM_OBJECT_LOCK(prev_object); 1833 if (prev_object->type != OBJT_DEFAULT && 1834 prev_object->type != OBJT_SWAP) { 1835 VM_OBJECT_UNLOCK(prev_object); 1836 return (FALSE); 1837 } 1838 1839 /* 1840 * Try to collapse the object first 1841 */ 1842 vm_object_collapse(prev_object); 1843 1844 /* 1845 * Can't coalesce if: . more than one reference . paged out . shadows 1846 * another object . has a copy elsewhere (any of which mean that the 1847 * pages not mapped to prev_entry may be in use anyway) 1848 */ 1849 if (prev_object->backing_object != NULL) { 1850 VM_OBJECT_UNLOCK(prev_object); 1851 return (FALSE); 1852 } 1853 1854 prev_size >>= PAGE_SHIFT; 1855 next_size >>= PAGE_SHIFT; 1856 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 1857 1858 if ((prev_object->ref_count > 1) && 1859 (prev_object->size != next_pindex)) { 1860 VM_OBJECT_UNLOCK(prev_object); 1861 return (FALSE); 1862 } 1863 1864 /* 1865 * Remove any pages that may still be in the object from a previous 1866 * deallocation. 1867 */ 1868 if (next_pindex < prev_object->size) { 1869 vm_object_page_remove(prev_object, 1870 next_pindex, 1871 next_pindex + next_size, FALSE); 1872 if (prev_object->type == OBJT_SWAP) 1873 swap_pager_freespace(prev_object, 1874 next_pindex, next_size); 1875 } 1876 1877 /* 1878 * Extend the object if necessary. 1879 */ 1880 if (next_pindex + next_size > prev_object->size) 1881 prev_object->size = next_pindex + next_size; 1882 1883 VM_OBJECT_UNLOCK(prev_object); 1884 return (TRUE); 1885 } 1886 1887 void 1888 vm_object_set_writeable_dirty(vm_object_t object) 1889 { 1890 struct vnode *vp; 1891 1892 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1893 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1894 if (object->type == OBJT_VNODE && 1895 (vp = (struct vnode *)object->handle) != NULL) { 1896 VI_LOCK(vp); 1897 if ((vp->v_iflag & VI_OBJDIRTY) == 0) 1898 vp->v_iflag |= VI_OBJDIRTY; 1899 VI_UNLOCK(vp); 1900 } 1901 } 1902 1903 #include "opt_ddb.h" 1904 #ifdef DDB 1905 #include <sys/kernel.h> 1906 1907 #include <sys/cons.h> 1908 1909 #include <ddb/ddb.h> 1910 1911 static int 1912 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1913 { 1914 vm_map_t tmpm; 1915 vm_map_entry_t tmpe; 1916 vm_object_t obj; 1917 int entcount; 1918 1919 if (map == 0) 1920 return 0; 1921 1922 if (entry == 0) { 1923 tmpe = map->header.next; 1924 entcount = map->nentries; 1925 while (entcount-- && (tmpe != &map->header)) { 1926 if (_vm_object_in_map(map, object, tmpe)) { 1927 return 1; 1928 } 1929 tmpe = tmpe->next; 1930 } 1931 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1932 tmpm = entry->object.sub_map; 1933 tmpe = tmpm->header.next; 1934 entcount = tmpm->nentries; 1935 while (entcount-- && tmpe != &tmpm->header) { 1936 if (_vm_object_in_map(tmpm, object, tmpe)) { 1937 return 1; 1938 } 1939 tmpe = tmpe->next; 1940 } 1941 } else if ((obj = entry->object.vm_object) != NULL) { 1942 for (; obj; obj = obj->backing_object) 1943 if (obj == object) { 1944 return 1; 1945 } 1946 } 1947 return 0; 1948 } 1949 1950 static int 1951 vm_object_in_map(vm_object_t object) 1952 { 1953 struct proc *p; 1954 1955 /* sx_slock(&allproc_lock); */ 1956 LIST_FOREACH(p, &allproc, p_list) { 1957 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1958 continue; 1959 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 1960 /* sx_sunlock(&allproc_lock); */ 1961 return 1; 1962 } 1963 } 1964 /* sx_sunlock(&allproc_lock); */ 1965 if (_vm_object_in_map(kernel_map, object, 0)) 1966 return 1; 1967 if (_vm_object_in_map(kmem_map, object, 0)) 1968 return 1; 1969 if (_vm_object_in_map(pager_map, object, 0)) 1970 return 1; 1971 if (_vm_object_in_map(buffer_map, object, 0)) 1972 return 1; 1973 return 0; 1974 } 1975 1976 DB_SHOW_COMMAND(vmochk, vm_object_check) 1977 { 1978 vm_object_t object; 1979 1980 /* 1981 * make sure that internal objs are in a map somewhere 1982 * and none have zero ref counts. 1983 */ 1984 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1985 if (object->handle == NULL && 1986 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1987 if (object->ref_count == 0) { 1988 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1989 (long)object->size); 1990 } 1991 if (!vm_object_in_map(object)) { 1992 db_printf( 1993 "vmochk: internal obj is not in a map: " 1994 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1995 object->ref_count, (u_long)object->size, 1996 (u_long)object->size, 1997 (void *)object->backing_object); 1998 } 1999 } 2000 } 2001 } 2002 2003 /* 2004 * vm_object_print: [ debug ] 2005 */ 2006 DB_SHOW_COMMAND(object, vm_object_print_static) 2007 { 2008 /* XXX convert args. */ 2009 vm_object_t object = (vm_object_t)addr; 2010 boolean_t full = have_addr; 2011 2012 vm_page_t p; 2013 2014 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2015 #define count was_count 2016 2017 int count; 2018 2019 if (object == NULL) 2020 return; 2021 2022 db_iprintf( 2023 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n", 2024 object, (int)object->type, (uintmax_t)object->size, 2025 object->resident_page_count, object->ref_count, object->flags); 2026 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2027 object->shadow_count, 2028 object->backing_object ? object->backing_object->ref_count : 0, 2029 object->backing_object, (uintmax_t)object->backing_object_offset); 2030 2031 if (!full) 2032 return; 2033 2034 db_indent += 2; 2035 count = 0; 2036 TAILQ_FOREACH(p, &object->memq, listq) { 2037 if (count == 0) 2038 db_iprintf("memory:="); 2039 else if (count == 6) { 2040 db_printf("\n"); 2041 db_iprintf(" ..."); 2042 count = 0; 2043 } else 2044 db_printf(","); 2045 count++; 2046 2047 db_printf("(off=0x%jx,page=0x%jx)", 2048 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2049 } 2050 if (count != 0) 2051 db_printf("\n"); 2052 db_indent -= 2; 2053 } 2054 2055 /* XXX. */ 2056 #undef count 2057 2058 /* XXX need this non-static entry for calling from vm_map_print. */ 2059 void 2060 vm_object_print( 2061 /* db_expr_t */ long addr, 2062 boolean_t have_addr, 2063 /* db_expr_t */ long count, 2064 char *modif) 2065 { 2066 vm_object_print_static(addr, have_addr, count, modif); 2067 } 2068 2069 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2070 { 2071 vm_object_t object; 2072 int nl = 0; 2073 int c; 2074 2075 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2076 vm_pindex_t idx, fidx; 2077 vm_pindex_t osize; 2078 vm_paddr_t pa = -1, padiff; 2079 int rcount; 2080 vm_page_t m; 2081 2082 db_printf("new object: %p\n", (void *)object); 2083 if (nl > 18) { 2084 c = cngetc(); 2085 if (c != ' ') 2086 return; 2087 nl = 0; 2088 } 2089 nl++; 2090 rcount = 0; 2091 fidx = 0; 2092 osize = object->size; 2093 if (osize > 128) 2094 osize = 128; 2095 for (idx = 0; idx < osize; idx++) { 2096 m = vm_page_lookup(object, idx); 2097 if (m == NULL) { 2098 if (rcount) { 2099 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2100 (long)fidx, rcount, (long)pa); 2101 if (nl > 18) { 2102 c = cngetc(); 2103 if (c != ' ') 2104 return; 2105 nl = 0; 2106 } 2107 nl++; 2108 rcount = 0; 2109 } 2110 continue; 2111 } 2112 2113 2114 if (rcount && 2115 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2116 ++rcount; 2117 continue; 2118 } 2119 if (rcount) { 2120 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 2121 padiff >>= PAGE_SHIFT; 2122 padiff &= PQ_L2_MASK; 2123 if (padiff == 0) { 2124 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 2125 ++rcount; 2126 continue; 2127 } 2128 db_printf(" index(%ld)run(%d)pa(0x%lx)", 2129 (long)fidx, rcount, (long)pa); 2130 db_printf("pd(%ld)\n", (long)padiff); 2131 if (nl > 18) { 2132 c = cngetc(); 2133 if (c != ' ') 2134 return; 2135 nl = 0; 2136 } 2137 nl++; 2138 } 2139 fidx = idx; 2140 pa = VM_PAGE_TO_PHYS(m); 2141 rcount = 1; 2142 } 2143 if (rcount) { 2144 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2145 (long)fidx, rcount, (long)pa); 2146 if (nl > 18) { 2147 c = cngetc(); 2148 if (c != ' ') 2149 return; 2150 nl = 0; 2151 } 2152 nl++; 2153 } 2154 } 2155 } 2156 #endif /* DDB */ 2157