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 int vm_object_zinit(void *mem, int size, int flags); 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 int 179 vm_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 } 193 194 void 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 */ 232 void 233 vm_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 } 255 256 void 257 vm_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 } 263 264 void 265 vm_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 } 271 272 void 273 vm_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 } 279 280 void 281 vm_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 } 291 292 void 293 vm_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 } 304 305 void 306 vm_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 */ 323 vm_object_t 324 vm_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 */ 341 vm_object_t 342 vm_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 */ 354 void 355 vm_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 */ 382 void 383 vm_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 */ 400 void 401 vm_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 */ 440 void 441 vm_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++; 508 retry: 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 } 541 doterm: 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 */ 571 void 572 vm_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_busy(p); 625 vm_page_free(p); 626 cnt.v_pfree++; 627 } else { 628 vm_page_busy(p); 629 vm_page_remove(p); 630 } 631 } 632 vm_page_unlock_queues(); 633 634 /* 635 * Let the pager know object is dead. 636 */ 637 vm_pager_deallocate(object); 638 VM_OBJECT_UNLOCK(object); 639 640 /* 641 * Remove the object from the global object list. 642 */ 643 mtx_lock(&vm_object_list_mtx); 644 TAILQ_REMOVE(&vm_object_list, object, object_list); 645 mtx_unlock(&vm_object_list_mtx); 646 647 wakeup(object); 648 649 /* 650 * Free the space for the object. 651 */ 652 uma_zfree(obj_zone, object); 653 } 654 655 /* 656 * vm_object_page_clean 657 * 658 * Clean all dirty pages in the specified range of object. Leaves page 659 * on whatever queue it is currently on. If NOSYNC is set then do not 660 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 661 * leaving the object dirty. 662 * 663 * When stuffing pages asynchronously, allow clustering. XXX we need a 664 * synchronous clustering mode implementation. 665 * 666 * Odd semantics: if start == end, we clean everything. 667 * 668 * The object must be locked. 669 */ 670 void 671 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 672 { 673 vm_page_t p, np; 674 vm_pindex_t tstart, tend; 675 vm_pindex_t pi; 676 int clearobjflags; 677 int pagerflags; 678 int curgeneration; 679 680 GIANT_REQUIRED; 681 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 682 if (object->type != OBJT_VNODE || 683 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 684 return; 685 686 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 687 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 688 689 vm_object_set_flag(object, OBJ_CLEANING); 690 691 tstart = start; 692 if (end == 0) { 693 tend = object->size; 694 } else { 695 tend = end; 696 } 697 698 vm_page_lock_queues(); 699 /* 700 * If the caller is smart and only msync()s a range he knows is 701 * dirty, we may be able to avoid an object scan. This results in 702 * a phenominal improvement in performance. We cannot do this 703 * as a matter of course because the object may be huge - e.g. 704 * the size might be in the gigabytes or terrabytes. 705 */ 706 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 707 vm_pindex_t tscan; 708 int scanlimit; 709 int scanreset; 710 711 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 712 if (scanreset < 16) 713 scanreset = 16; 714 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 715 716 scanlimit = scanreset; 717 tscan = tstart; 718 while (tscan < tend) { 719 curgeneration = object->generation; 720 p = vm_page_lookup(object, tscan); 721 if (p == NULL || p->valid == 0 || 722 (p->queue - p->pc) == PQ_CACHE) { 723 if (--scanlimit == 0) 724 break; 725 ++tscan; 726 continue; 727 } 728 vm_page_test_dirty(p); 729 if ((p->dirty & p->valid) == 0) { 730 if (--scanlimit == 0) 731 break; 732 ++tscan; 733 continue; 734 } 735 /* 736 * If we have been asked to skip nosync pages and 737 * this is a nosync page, we can't continue. 738 */ 739 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 740 if (--scanlimit == 0) 741 break; 742 ++tscan; 743 continue; 744 } 745 scanlimit = scanreset; 746 747 /* 748 * This returns 0 if it was unable to busy the first 749 * page (i.e. had to sleep). 750 */ 751 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 752 } 753 754 /* 755 * If everything was dirty and we flushed it successfully, 756 * and the requested range is not the entire object, we 757 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 758 * return immediately. 759 */ 760 if (tscan >= tend && (tstart || tend < object->size)) { 761 vm_page_unlock_queues(); 762 vm_object_clear_flag(object, OBJ_CLEANING); 763 return; 764 } 765 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 766 } 767 768 /* 769 * Generally set CLEANCHK interlock and make the page read-only so 770 * we can then clear the object flags. 771 * 772 * However, if this is a nosync mmap then the object is likely to 773 * stay dirty so do not mess with the page and do not clear the 774 * object flags. 775 */ 776 clearobjflags = 1; 777 TAILQ_FOREACH(p, &object->memq, listq) { 778 vm_page_flag_set(p, PG_CLEANCHK); 779 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 780 clearobjflags = 0; 781 else 782 pmap_page_protect(p, VM_PROT_READ); 783 } 784 785 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 786 struct vnode *vp; 787 788 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 789 if (object->type == OBJT_VNODE && 790 (vp = (struct vnode *)object->handle) != NULL) { 791 VI_LOCK(vp); 792 if (vp->v_iflag & VI_OBJDIRTY) 793 vp->v_iflag &= ~VI_OBJDIRTY; 794 VI_UNLOCK(vp); 795 } 796 } 797 798 rescan: 799 curgeneration = object->generation; 800 801 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 802 int n; 803 804 np = TAILQ_NEXT(p, listq); 805 806 again: 807 pi = p->pindex; 808 if (((p->flags & PG_CLEANCHK) == 0) || 809 (pi < tstart) || (pi >= tend) || 810 (p->valid == 0) || 811 ((p->queue - p->pc) == PQ_CACHE)) { 812 vm_page_flag_clear(p, PG_CLEANCHK); 813 continue; 814 } 815 816 vm_page_test_dirty(p); 817 if ((p->dirty & p->valid) == 0) { 818 vm_page_flag_clear(p, PG_CLEANCHK); 819 continue; 820 } 821 822 /* 823 * If we have been asked to skip nosync pages and this is a 824 * nosync page, skip it. Note that the object flags were 825 * not cleared in this case so we do not have to set them. 826 */ 827 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 828 vm_page_flag_clear(p, PG_CLEANCHK); 829 continue; 830 } 831 832 n = vm_object_page_collect_flush(object, p, 833 curgeneration, pagerflags); 834 if (n == 0) 835 goto rescan; 836 837 if (object->generation != curgeneration) 838 goto rescan; 839 840 /* 841 * Try to optimize the next page. If we can't we pick up 842 * our (random) scan where we left off. 843 */ 844 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 845 if ((p = vm_page_lookup(object, pi + n)) != NULL) 846 goto again; 847 } 848 } 849 vm_page_unlock_queues(); 850 #if 0 851 VOP_FSYNC(vp, NULL, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 852 #endif 853 854 vm_object_clear_flag(object, OBJ_CLEANING); 855 return; 856 } 857 858 static int 859 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 860 { 861 int runlen; 862 int maxf; 863 int chkb; 864 int maxb; 865 int i; 866 vm_pindex_t pi; 867 vm_page_t maf[vm_pageout_page_count]; 868 vm_page_t mab[vm_pageout_page_count]; 869 vm_page_t ma[vm_pageout_page_count]; 870 871 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 872 pi = p->pindex; 873 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 874 vm_page_lock_queues(); 875 if (object->generation != curgeneration) { 876 return(0); 877 } 878 } 879 maxf = 0; 880 for(i = 1; i < vm_pageout_page_count; i++) { 881 vm_page_t tp; 882 883 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 884 if ((tp->flags & PG_BUSY) || 885 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 886 (tp->flags & PG_CLEANCHK) == 0) || 887 (tp->busy != 0)) 888 break; 889 if((tp->queue - tp->pc) == PQ_CACHE) { 890 vm_page_flag_clear(tp, PG_CLEANCHK); 891 break; 892 } 893 vm_page_test_dirty(tp); 894 if ((tp->dirty & tp->valid) == 0) { 895 vm_page_flag_clear(tp, PG_CLEANCHK); 896 break; 897 } 898 maf[ i - 1 ] = tp; 899 maxf++; 900 continue; 901 } 902 break; 903 } 904 905 maxb = 0; 906 chkb = vm_pageout_page_count - maxf; 907 if (chkb) { 908 for(i = 1; i < chkb;i++) { 909 vm_page_t tp; 910 911 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 912 if ((tp->flags & PG_BUSY) || 913 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 914 (tp->flags & PG_CLEANCHK) == 0) || 915 (tp->busy != 0)) 916 break; 917 if ((tp->queue - tp->pc) == PQ_CACHE) { 918 vm_page_flag_clear(tp, PG_CLEANCHK); 919 break; 920 } 921 vm_page_test_dirty(tp); 922 if ((tp->dirty & tp->valid) == 0) { 923 vm_page_flag_clear(tp, PG_CLEANCHK); 924 break; 925 } 926 mab[ i - 1 ] = tp; 927 maxb++; 928 continue; 929 } 930 break; 931 } 932 } 933 934 for(i = 0; i < maxb; i++) { 935 int index = (maxb - i) - 1; 936 ma[index] = mab[i]; 937 vm_page_flag_clear(ma[index], PG_CLEANCHK); 938 } 939 vm_page_flag_clear(p, PG_CLEANCHK); 940 ma[maxb] = p; 941 for(i = 0; i < maxf; i++) { 942 int index = (maxb + i) + 1; 943 ma[index] = maf[i]; 944 vm_page_flag_clear(ma[index], PG_CLEANCHK); 945 } 946 runlen = maxb + maxf + 1; 947 948 vm_pageout_flush(ma, runlen, pagerflags); 949 for (i = 0; i < runlen; i++) { 950 if (ma[i]->valid & ma[i]->dirty) { 951 pmap_page_protect(ma[i], VM_PROT_READ); 952 vm_page_flag_set(ma[i], PG_CLEANCHK); 953 954 /* 955 * maxf will end up being the actual number of pages 956 * we wrote out contiguously, non-inclusive of the 957 * first page. We do not count look-behind pages. 958 */ 959 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 960 maxf = i - maxb - 1; 961 } 962 } 963 return(maxf + 1); 964 } 965 966 /* 967 * Note that there is absolutely no sense in writing out 968 * anonymous objects, so we track down the vnode object 969 * to write out. 970 * We invalidate (remove) all pages from the address space 971 * for semantic correctness. 972 * 973 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 974 * may start out with a NULL object. 975 */ 976 void 977 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 978 boolean_t syncio, boolean_t invalidate) 979 { 980 vm_object_t backing_object; 981 struct vnode *vp; 982 int flags; 983 984 if (object == NULL) 985 return; 986 VM_OBJECT_LOCK(object); 987 while ((backing_object = object->backing_object) != NULL) { 988 VM_OBJECT_LOCK(backing_object); 989 offset += object->backing_object_offset; 990 VM_OBJECT_UNLOCK(object); 991 object = backing_object; 992 if (object->size < OFF_TO_IDX(offset + size)) 993 size = IDX_TO_OFF(object->size) - offset; 994 } 995 /* 996 * Flush pages if writing is allowed, invalidate them 997 * if invalidation requested. Pages undergoing I/O 998 * will be ignored by vm_object_page_remove(). 999 * 1000 * We cannot lock the vnode and then wait for paging 1001 * to complete without deadlocking against vm_fault. 1002 * Instead we simply call vm_object_page_remove() and 1003 * allow it to block internally on a page-by-page 1004 * basis when it encounters pages undergoing async 1005 * I/O. 1006 */ 1007 if (object->type == OBJT_VNODE && 1008 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1009 vp = object->handle; 1010 VM_OBJECT_UNLOCK(object); 1011 mtx_lock(&Giant); 1012 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 1013 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1014 flags |= invalidate ? OBJPC_INVAL : 0; 1015 VM_OBJECT_LOCK(object); 1016 vm_object_page_clean(object, 1017 OFF_TO_IDX(offset), 1018 OFF_TO_IDX(offset + size + PAGE_MASK), 1019 flags); 1020 VM_OBJECT_UNLOCK(object); 1021 VOP_UNLOCK(vp, 0, curthread); 1022 mtx_unlock(&Giant); 1023 VM_OBJECT_LOCK(object); 1024 } 1025 if ((object->type == OBJT_VNODE || 1026 object->type == OBJT_DEVICE) && invalidate) { 1027 boolean_t purge; 1028 purge = old_msync || (object->type == OBJT_DEVICE); 1029 vm_object_page_remove(object, 1030 OFF_TO_IDX(offset), 1031 OFF_TO_IDX(offset + size + PAGE_MASK), 1032 purge ? FALSE : TRUE); 1033 } 1034 VM_OBJECT_UNLOCK(object); 1035 } 1036 1037 /* 1038 * vm_object_madvise: 1039 * 1040 * Implements the madvise function at the object/page level. 1041 * 1042 * MADV_WILLNEED (any object) 1043 * 1044 * Activate the specified pages if they are resident. 1045 * 1046 * MADV_DONTNEED (any object) 1047 * 1048 * Deactivate the specified pages if they are resident. 1049 * 1050 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1051 * OBJ_ONEMAPPING only) 1052 * 1053 * Deactivate and clean the specified pages if they are 1054 * resident. This permits the process to reuse the pages 1055 * without faulting or the kernel to reclaim the pages 1056 * without I/O. 1057 */ 1058 void 1059 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1060 { 1061 vm_pindex_t end, tpindex; 1062 vm_object_t backing_object, tobject; 1063 vm_page_t m; 1064 1065 if (object == NULL) 1066 return; 1067 end = pindex + count; 1068 /* 1069 * Locate and adjust resident pages 1070 */ 1071 for (; pindex < end; pindex += 1) { 1072 relookup: 1073 tobject = object; 1074 tpindex = pindex; 1075 VM_OBJECT_LOCK(tobject); 1076 shadowlookup: 1077 /* 1078 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1079 * and those pages must be OBJ_ONEMAPPING. 1080 */ 1081 if (advise == MADV_FREE) { 1082 if ((tobject->type != OBJT_DEFAULT && 1083 tobject->type != OBJT_SWAP) || 1084 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1085 goto unlock_tobject; 1086 } 1087 } 1088 m = vm_page_lookup(tobject, tpindex); 1089 if (m == NULL) { 1090 /* 1091 * There may be swap even if there is no backing page 1092 */ 1093 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1094 swap_pager_freespace(tobject, tpindex, 1); 1095 /* 1096 * next object 1097 */ 1098 backing_object = tobject->backing_object; 1099 if (backing_object == NULL) 1100 goto unlock_tobject; 1101 VM_OBJECT_LOCK(backing_object); 1102 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1103 VM_OBJECT_UNLOCK(tobject); 1104 tobject = backing_object; 1105 goto shadowlookup; 1106 } 1107 /* 1108 * If the page is busy or not in a normal active state, 1109 * we skip it. If the page is not managed there are no 1110 * page queues to mess with. Things can break if we mess 1111 * with pages in any of the below states. 1112 */ 1113 vm_page_lock_queues(); 1114 if (m->hold_count || 1115 m->wire_count || 1116 (m->flags & PG_UNMANAGED) || 1117 m->valid != VM_PAGE_BITS_ALL) { 1118 vm_page_unlock_queues(); 1119 goto unlock_tobject; 1120 } 1121 if (vm_page_sleep_if_busy(m, TRUE, "madvpo")) { 1122 VM_OBJECT_UNLOCK(tobject); 1123 goto relookup; 1124 } 1125 if (advise == MADV_WILLNEED) { 1126 vm_page_activate(m); 1127 } else if (advise == MADV_DONTNEED) { 1128 vm_page_dontneed(m); 1129 } else if (advise == MADV_FREE) { 1130 /* 1131 * Mark the page clean. This will allow the page 1132 * to be freed up by the system. However, such pages 1133 * are often reused quickly by malloc()/free() 1134 * so we do not do anything that would cause 1135 * a page fault if we can help it. 1136 * 1137 * Specifically, we do not try to actually free 1138 * the page now nor do we try to put it in the 1139 * cache (which would cause a page fault on reuse). 1140 * 1141 * But we do make the page is freeable as we 1142 * can without actually taking the step of unmapping 1143 * it. 1144 */ 1145 pmap_clear_modify(m); 1146 m->dirty = 0; 1147 m->act_count = 0; 1148 vm_page_dontneed(m); 1149 } 1150 vm_page_unlock_queues(); 1151 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1152 swap_pager_freespace(tobject, tpindex, 1); 1153 unlock_tobject: 1154 VM_OBJECT_UNLOCK(tobject); 1155 } 1156 } 1157 1158 /* 1159 * vm_object_shadow: 1160 * 1161 * Create a new object which is backed by the 1162 * specified existing object range. The source 1163 * object reference is deallocated. 1164 * 1165 * The new object and offset into that object 1166 * are returned in the source parameters. 1167 */ 1168 void 1169 vm_object_shadow( 1170 vm_object_t *object, /* IN/OUT */ 1171 vm_ooffset_t *offset, /* IN/OUT */ 1172 vm_size_t length) 1173 { 1174 vm_object_t source; 1175 vm_object_t result; 1176 1177 source = *object; 1178 1179 /* 1180 * Don't create the new object if the old object isn't shared. 1181 */ 1182 if (source != NULL) { 1183 VM_OBJECT_LOCK(source); 1184 if (source->ref_count == 1 && 1185 source->handle == NULL && 1186 (source->type == OBJT_DEFAULT || 1187 source->type == OBJT_SWAP)) { 1188 VM_OBJECT_UNLOCK(source); 1189 return; 1190 } 1191 VM_OBJECT_UNLOCK(source); 1192 } 1193 1194 /* 1195 * Allocate a new object with the given length. 1196 */ 1197 result = vm_object_allocate(OBJT_DEFAULT, length); 1198 1199 /* 1200 * The new object shadows the source object, adding a reference to it. 1201 * Our caller changes his reference to point to the new object, 1202 * removing a reference to the source object. Net result: no change 1203 * of reference count. 1204 * 1205 * Try to optimize the result object's page color when shadowing 1206 * in order to maintain page coloring consistency in the combined 1207 * shadowed object. 1208 */ 1209 result->backing_object = source; 1210 /* 1211 * Store the offset into the source object, and fix up the offset into 1212 * the new object. 1213 */ 1214 result->backing_object_offset = *offset; 1215 if (source != NULL) { 1216 VM_OBJECT_LOCK(source); 1217 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1218 source->shadow_count++; 1219 source->generation++; 1220 if (length < source->size) 1221 length = source->size; 1222 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 || 1223 source->generation > 1) 1224 length = PQ_L2_SIZE / 3 + PQ_PRIME1; 1225 result->pg_color = (source->pg_color + 1226 length * source->generation) & PQ_L2_MASK; 1227 VM_OBJECT_UNLOCK(source); 1228 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & 1229 PQ_L2_MASK; 1230 } 1231 1232 1233 /* 1234 * Return the new things 1235 */ 1236 *offset = 0; 1237 *object = result; 1238 } 1239 1240 /* 1241 * vm_object_split: 1242 * 1243 * Split the pages in a map entry into a new object. This affords 1244 * easier removal of unused pages, and keeps object inheritance from 1245 * being a negative impact on memory usage. 1246 */ 1247 void 1248 vm_object_split(vm_map_entry_t entry) 1249 { 1250 vm_page_t m; 1251 vm_object_t orig_object, new_object, source; 1252 vm_pindex_t offidxstart, offidxend; 1253 vm_size_t idx, size; 1254 1255 orig_object = entry->object.vm_object; 1256 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1257 return; 1258 if (orig_object->ref_count <= 1) 1259 return; 1260 VM_OBJECT_UNLOCK(orig_object); 1261 1262 offidxstart = OFF_TO_IDX(entry->offset); 1263 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); 1264 size = offidxend - offidxstart; 1265 1266 /* 1267 * If swap_pager_copy() is later called, it will convert new_object 1268 * into a swap object. 1269 */ 1270 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1271 1272 VM_OBJECT_LOCK(new_object); 1273 VM_OBJECT_LOCK(orig_object); 1274 source = orig_object->backing_object; 1275 if (source != NULL) { 1276 VM_OBJECT_LOCK(source); 1277 LIST_INSERT_HEAD(&source->shadow_head, 1278 new_object, shadow_list); 1279 source->shadow_count++; 1280 source->generation++; 1281 vm_object_reference_locked(source); /* for new_object */ 1282 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1283 VM_OBJECT_UNLOCK(source); 1284 new_object->backing_object_offset = 1285 orig_object->backing_object_offset + entry->offset; 1286 new_object->backing_object = source; 1287 } 1288 for (idx = 0; idx < size; idx++) { 1289 retry: 1290 m = vm_page_lookup(orig_object, offidxstart + idx); 1291 if (m == NULL) 1292 continue; 1293 1294 /* 1295 * We must wait for pending I/O to complete before we can 1296 * rename the page. 1297 * 1298 * We do not have to VM_PROT_NONE the page as mappings should 1299 * not be changed by this operation. 1300 */ 1301 vm_page_lock_queues(); 1302 if ((m->flags & PG_BUSY) || m->busy) { 1303 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1304 VM_OBJECT_UNLOCK(orig_object); 1305 VM_OBJECT_UNLOCK(new_object); 1306 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0); 1307 VM_OBJECT_LOCK(new_object); 1308 VM_OBJECT_LOCK(orig_object); 1309 goto retry; 1310 } 1311 vm_page_busy(m); 1312 vm_page_rename(m, new_object, idx); 1313 /* page automatically made dirty by rename and cache handled */ 1314 vm_page_busy(m); 1315 vm_page_unlock_queues(); 1316 } 1317 if (orig_object->type == OBJT_SWAP) { 1318 /* 1319 * swap_pager_copy() can sleep, in which case the orig_object's 1320 * and new_object's locks are released and reacquired. 1321 */ 1322 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1323 } 1324 VM_OBJECT_UNLOCK(orig_object); 1325 vm_page_lock_queues(); 1326 TAILQ_FOREACH(m, &new_object->memq, listq) 1327 vm_page_wakeup(m); 1328 vm_page_unlock_queues(); 1329 VM_OBJECT_UNLOCK(new_object); 1330 entry->object.vm_object = new_object; 1331 entry->offset = 0LL; 1332 vm_object_deallocate(orig_object); 1333 VM_OBJECT_LOCK(new_object); 1334 } 1335 1336 #define OBSC_TEST_ALL_SHADOWED 0x0001 1337 #define OBSC_COLLAPSE_NOWAIT 0x0002 1338 #define OBSC_COLLAPSE_WAIT 0x0004 1339 1340 static int 1341 vm_object_backing_scan(vm_object_t object, int op) 1342 { 1343 int r = 1; 1344 vm_page_t p; 1345 vm_object_t backing_object; 1346 vm_pindex_t backing_offset_index; 1347 1348 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1349 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1350 1351 backing_object = object->backing_object; 1352 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1353 1354 /* 1355 * Initial conditions 1356 */ 1357 if (op & OBSC_TEST_ALL_SHADOWED) { 1358 /* 1359 * We do not want to have to test for the existence of 1360 * swap pages in the backing object. XXX but with the 1361 * new swapper this would be pretty easy to do. 1362 * 1363 * XXX what about anonymous MAP_SHARED memory that hasn't 1364 * been ZFOD faulted yet? If we do not test for this, the 1365 * shadow test may succeed! XXX 1366 */ 1367 if (backing_object->type != OBJT_DEFAULT) { 1368 return (0); 1369 } 1370 } 1371 if (op & OBSC_COLLAPSE_WAIT) { 1372 vm_object_set_flag(backing_object, OBJ_DEAD); 1373 } 1374 1375 /* 1376 * Our scan 1377 */ 1378 p = TAILQ_FIRST(&backing_object->memq); 1379 while (p) { 1380 vm_page_t next = TAILQ_NEXT(p, listq); 1381 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1382 1383 if (op & OBSC_TEST_ALL_SHADOWED) { 1384 vm_page_t pp; 1385 1386 /* 1387 * Ignore pages outside the parent object's range 1388 * and outside the parent object's mapping of the 1389 * backing object. 1390 * 1391 * note that we do not busy the backing object's 1392 * page. 1393 */ 1394 if ( 1395 p->pindex < backing_offset_index || 1396 new_pindex >= object->size 1397 ) { 1398 p = next; 1399 continue; 1400 } 1401 1402 /* 1403 * See if the parent has the page or if the parent's 1404 * object pager has the page. If the parent has the 1405 * page but the page is not valid, the parent's 1406 * object pager must have the page. 1407 * 1408 * If this fails, the parent does not completely shadow 1409 * the object and we might as well give up now. 1410 */ 1411 1412 pp = vm_page_lookup(object, new_pindex); 1413 if ( 1414 (pp == NULL || pp->valid == 0) && 1415 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1416 ) { 1417 r = 0; 1418 break; 1419 } 1420 } 1421 1422 /* 1423 * Check for busy page 1424 */ 1425 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1426 vm_page_t pp; 1427 1428 vm_page_lock_queues(); 1429 if (op & OBSC_COLLAPSE_NOWAIT) { 1430 if ((p->flags & PG_BUSY) || 1431 !p->valid || 1432 p->hold_count || 1433 p->wire_count || 1434 p->busy) { 1435 vm_page_unlock_queues(); 1436 p = next; 1437 continue; 1438 } 1439 } else if (op & OBSC_COLLAPSE_WAIT) { 1440 if ((p->flags & PG_BUSY) || p->busy) { 1441 vm_page_flag_set(p, 1442 PG_WANTED | PG_REFERENCED); 1443 VM_OBJECT_UNLOCK(backing_object); 1444 VM_OBJECT_UNLOCK(object); 1445 msleep(p, &vm_page_queue_mtx, 1446 PDROP | PVM, "vmocol", 0); 1447 VM_OBJECT_LOCK(object); 1448 VM_OBJECT_LOCK(backing_object); 1449 /* 1450 * If we slept, anything could have 1451 * happened. Since the object is 1452 * marked dead, the backing offset 1453 * should not have changed so we 1454 * just restart our scan. 1455 */ 1456 p = TAILQ_FIRST(&backing_object->memq); 1457 continue; 1458 } 1459 } 1460 1461 /* 1462 * Busy the page 1463 */ 1464 vm_page_busy(p); 1465 vm_page_unlock_queues(); 1466 1467 KASSERT( 1468 p->object == backing_object, 1469 ("vm_object_qcollapse(): object mismatch") 1470 ); 1471 1472 /* 1473 * Destroy any associated swap 1474 */ 1475 if (backing_object->type == OBJT_SWAP) { 1476 swap_pager_freespace( 1477 backing_object, 1478 p->pindex, 1479 1 1480 ); 1481 } 1482 1483 if ( 1484 p->pindex < backing_offset_index || 1485 new_pindex >= object->size 1486 ) { 1487 /* 1488 * Page is out of the parent object's range, we 1489 * can simply destroy it. 1490 */ 1491 vm_page_lock_queues(); 1492 pmap_remove_all(p); 1493 vm_page_free(p); 1494 vm_page_unlock_queues(); 1495 p = next; 1496 continue; 1497 } 1498 1499 pp = vm_page_lookup(object, new_pindex); 1500 if ( 1501 pp != NULL || 1502 vm_pager_has_page(object, new_pindex, NULL, NULL) 1503 ) { 1504 /* 1505 * page already exists in parent OR swap exists 1506 * for this location in the parent. Destroy 1507 * the original page from the backing object. 1508 * 1509 * Leave the parent's page alone 1510 */ 1511 vm_page_lock_queues(); 1512 pmap_remove_all(p); 1513 vm_page_free(p); 1514 vm_page_unlock_queues(); 1515 p = next; 1516 continue; 1517 } 1518 1519 /* 1520 * Page does not exist in parent, rename the 1521 * page from the backing object to the main object. 1522 * 1523 * If the page was mapped to a process, it can remain 1524 * mapped through the rename. 1525 */ 1526 vm_page_lock_queues(); 1527 vm_page_rename(p, object, new_pindex); 1528 vm_page_unlock_queues(); 1529 /* page automatically made dirty by rename */ 1530 } 1531 p = next; 1532 } 1533 return (r); 1534 } 1535 1536 1537 /* 1538 * this version of collapse allows the operation to occur earlier and 1539 * when paging_in_progress is true for an object... This is not a complete 1540 * operation, but should plug 99.9% of the rest of the leaks. 1541 */ 1542 static void 1543 vm_object_qcollapse(vm_object_t object) 1544 { 1545 vm_object_t backing_object = object->backing_object; 1546 1547 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1548 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1549 1550 if (backing_object->ref_count != 1) 1551 return; 1552 1553 backing_object->ref_count += 2; 1554 1555 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1556 1557 backing_object->ref_count -= 2; 1558 } 1559 1560 /* 1561 * vm_object_collapse: 1562 * 1563 * Collapse an object with the object backing it. 1564 * Pages in the backing object are moved into the 1565 * parent, and the backing object is deallocated. 1566 */ 1567 void 1568 vm_object_collapse(vm_object_t object) 1569 { 1570 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1571 1572 while (TRUE) { 1573 vm_object_t backing_object; 1574 1575 /* 1576 * Verify that the conditions are right for collapse: 1577 * 1578 * The object exists and the backing object exists. 1579 */ 1580 if ((backing_object = object->backing_object) == NULL) 1581 break; 1582 1583 /* 1584 * we check the backing object first, because it is most likely 1585 * not collapsable. 1586 */ 1587 VM_OBJECT_LOCK(backing_object); 1588 if (backing_object->handle != NULL || 1589 (backing_object->type != OBJT_DEFAULT && 1590 backing_object->type != OBJT_SWAP) || 1591 (backing_object->flags & OBJ_DEAD) || 1592 object->handle != NULL || 1593 (object->type != OBJT_DEFAULT && 1594 object->type != OBJT_SWAP) || 1595 (object->flags & OBJ_DEAD)) { 1596 VM_OBJECT_UNLOCK(backing_object); 1597 break; 1598 } 1599 1600 if ( 1601 object->paging_in_progress != 0 || 1602 backing_object->paging_in_progress != 0 1603 ) { 1604 vm_object_qcollapse(object); 1605 VM_OBJECT_UNLOCK(backing_object); 1606 break; 1607 } 1608 /* 1609 * We know that we can either collapse the backing object (if 1610 * the parent is the only reference to it) or (perhaps) have 1611 * the parent bypass the object if the parent happens to shadow 1612 * all the resident pages in the entire backing object. 1613 * 1614 * This is ignoring pager-backed pages such as swap pages. 1615 * vm_object_backing_scan fails the shadowing test in this 1616 * case. 1617 */ 1618 if (backing_object->ref_count == 1) { 1619 /* 1620 * If there is exactly one reference to the backing 1621 * object, we can collapse it into the parent. 1622 */ 1623 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1624 1625 /* 1626 * Move the pager from backing_object to object. 1627 */ 1628 if (backing_object->type == OBJT_SWAP) { 1629 /* 1630 * swap_pager_copy() can sleep, in which case 1631 * the backing_object's and object's locks are 1632 * released and reacquired. 1633 */ 1634 swap_pager_copy( 1635 backing_object, 1636 object, 1637 OFF_TO_IDX(object->backing_object_offset), TRUE); 1638 } 1639 /* 1640 * Object now shadows whatever backing_object did. 1641 * Note that the reference to 1642 * backing_object->backing_object moves from within 1643 * backing_object to within object. 1644 */ 1645 LIST_REMOVE(object, shadow_list); 1646 backing_object->shadow_count--; 1647 backing_object->generation++; 1648 if (backing_object->backing_object) { 1649 VM_OBJECT_LOCK(backing_object->backing_object); 1650 LIST_REMOVE(backing_object, shadow_list); 1651 LIST_INSERT_HEAD( 1652 &backing_object->backing_object->shadow_head, 1653 object, shadow_list); 1654 /* 1655 * The shadow_count has not changed. 1656 */ 1657 backing_object->backing_object->generation++; 1658 VM_OBJECT_UNLOCK(backing_object->backing_object); 1659 } 1660 object->backing_object = backing_object->backing_object; 1661 object->backing_object_offset += 1662 backing_object->backing_object_offset; 1663 1664 /* 1665 * Discard backing_object. 1666 * 1667 * Since the backing object has no pages, no pager left, 1668 * and no object references within it, all that is 1669 * necessary is to dispose of it. 1670 */ 1671 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1672 VM_OBJECT_UNLOCK(backing_object); 1673 1674 mtx_lock(&vm_object_list_mtx); 1675 TAILQ_REMOVE( 1676 &vm_object_list, 1677 backing_object, 1678 object_list 1679 ); 1680 mtx_unlock(&vm_object_list_mtx); 1681 1682 uma_zfree(obj_zone, backing_object); 1683 1684 object_collapses++; 1685 } else { 1686 vm_object_t new_backing_object; 1687 1688 /* 1689 * If we do not entirely shadow the backing object, 1690 * there is nothing we can do so we give up. 1691 */ 1692 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1693 VM_OBJECT_UNLOCK(backing_object); 1694 break; 1695 } 1696 1697 /* 1698 * Make the parent shadow the next object in the 1699 * chain. Deallocating backing_object will not remove 1700 * it, since its reference count is at least 2. 1701 */ 1702 LIST_REMOVE(object, shadow_list); 1703 backing_object->shadow_count--; 1704 backing_object->generation++; 1705 1706 new_backing_object = backing_object->backing_object; 1707 if ((object->backing_object = new_backing_object) != NULL) { 1708 VM_OBJECT_LOCK(new_backing_object); 1709 LIST_INSERT_HEAD( 1710 &new_backing_object->shadow_head, 1711 object, 1712 shadow_list 1713 ); 1714 new_backing_object->shadow_count++; 1715 new_backing_object->generation++; 1716 vm_object_reference_locked(new_backing_object); 1717 VM_OBJECT_UNLOCK(new_backing_object); 1718 object->backing_object_offset += 1719 backing_object->backing_object_offset; 1720 } 1721 1722 /* 1723 * Drop the reference count on backing_object. Since 1724 * its ref_count was at least 2, it will not vanish. 1725 */ 1726 backing_object->ref_count--; 1727 VM_OBJECT_UNLOCK(backing_object); 1728 object_bypasses++; 1729 } 1730 1731 /* 1732 * Try again with this object's new backing object. 1733 */ 1734 } 1735 } 1736 1737 /* 1738 * vm_object_page_remove: 1739 * 1740 * Removes all physical pages in the given range from the 1741 * object's list of pages. If the range's end is zero, all 1742 * physical pages from the range's start to the end of the object 1743 * are deleted. 1744 * 1745 * The object must be locked. 1746 */ 1747 void 1748 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1749 boolean_t clean_only) 1750 { 1751 vm_page_t p, next; 1752 1753 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1754 if (object->resident_page_count == 0) 1755 return; 1756 1757 /* 1758 * Since physically-backed objects do not use managed pages, we can't 1759 * remove pages from the object (we must instead remove the page 1760 * references, and then destroy the object). 1761 */ 1762 KASSERT(object->type != OBJT_PHYS, 1763 ("attempt to remove pages from a physical object")); 1764 1765 vm_object_pip_add(object, 1); 1766 again: 1767 vm_page_lock_queues(); 1768 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1769 if (p->pindex < start) { 1770 p = vm_page_splay(start, object->root); 1771 if ((object->root = p)->pindex < start) 1772 p = TAILQ_NEXT(p, listq); 1773 } 1774 } 1775 /* 1776 * Assert: the variable p is either (1) the page with the 1777 * least pindex greater than or equal to the parameter pindex 1778 * or (2) NULL. 1779 */ 1780 for (; 1781 p != NULL && (p->pindex < end || end == 0); 1782 p = next) { 1783 next = TAILQ_NEXT(p, listq); 1784 1785 if (p->wire_count != 0) { 1786 pmap_remove_all(p); 1787 if (!clean_only) 1788 p->valid = 0; 1789 continue; 1790 } 1791 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1792 goto again; 1793 if (clean_only && p->valid) { 1794 pmap_page_protect(p, VM_PROT_READ | VM_PROT_EXECUTE); 1795 if (p->valid & p->dirty) 1796 continue; 1797 } 1798 vm_page_busy(p); 1799 pmap_remove_all(p); 1800 vm_page_free(p); 1801 } 1802 vm_page_unlock_queues(); 1803 vm_object_pip_wakeup(object); 1804 } 1805 1806 /* 1807 * Routine: vm_object_coalesce 1808 * Function: Coalesces two objects backing up adjoining 1809 * regions of memory into a single object. 1810 * 1811 * returns TRUE if objects were combined. 1812 * 1813 * NOTE: Only works at the moment if the second object is NULL - 1814 * if it's not, which object do we lock first? 1815 * 1816 * Parameters: 1817 * prev_object First object to coalesce 1818 * prev_offset Offset into prev_object 1819 * prev_size Size of reference to prev_object 1820 * next_size Size of reference to the second object 1821 * 1822 * Conditions: 1823 * The object must *not* be locked. 1824 */ 1825 boolean_t 1826 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 1827 vm_size_t prev_size, vm_size_t next_size) 1828 { 1829 vm_pindex_t next_pindex; 1830 1831 if (prev_object == NULL) 1832 return (TRUE); 1833 VM_OBJECT_LOCK(prev_object); 1834 if (prev_object->type != OBJT_DEFAULT && 1835 prev_object->type != OBJT_SWAP) { 1836 VM_OBJECT_UNLOCK(prev_object); 1837 return (FALSE); 1838 } 1839 1840 /* 1841 * Try to collapse the object first 1842 */ 1843 vm_object_collapse(prev_object); 1844 1845 /* 1846 * Can't coalesce if: . more than one reference . paged out . shadows 1847 * another object . has a copy elsewhere (any of which mean that the 1848 * pages not mapped to prev_entry may be in use anyway) 1849 */ 1850 if (prev_object->backing_object != NULL) { 1851 VM_OBJECT_UNLOCK(prev_object); 1852 return (FALSE); 1853 } 1854 1855 prev_size >>= PAGE_SHIFT; 1856 next_size >>= PAGE_SHIFT; 1857 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 1858 1859 if ((prev_object->ref_count > 1) && 1860 (prev_object->size != next_pindex)) { 1861 VM_OBJECT_UNLOCK(prev_object); 1862 return (FALSE); 1863 } 1864 1865 /* 1866 * Remove any pages that may still be in the object from a previous 1867 * deallocation. 1868 */ 1869 if (next_pindex < prev_object->size) { 1870 vm_object_page_remove(prev_object, 1871 next_pindex, 1872 next_pindex + next_size, FALSE); 1873 if (prev_object->type == OBJT_SWAP) 1874 swap_pager_freespace(prev_object, 1875 next_pindex, next_size); 1876 } 1877 1878 /* 1879 * Extend the object if necessary. 1880 */ 1881 if (next_pindex + next_size > prev_object->size) 1882 prev_object->size = next_pindex + next_size; 1883 1884 VM_OBJECT_UNLOCK(prev_object); 1885 return (TRUE); 1886 } 1887 1888 void 1889 vm_object_set_writeable_dirty(vm_object_t object) 1890 { 1891 struct vnode *vp; 1892 1893 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1894 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1895 if (object->type == OBJT_VNODE && 1896 (vp = (struct vnode *)object->handle) != NULL) { 1897 VI_LOCK(vp); 1898 if ((vp->v_iflag & VI_OBJDIRTY) == 0) 1899 vp->v_iflag |= VI_OBJDIRTY; 1900 VI_UNLOCK(vp); 1901 } 1902 } 1903 1904 #include "opt_ddb.h" 1905 #ifdef DDB 1906 #include <sys/kernel.h> 1907 1908 #include <sys/cons.h> 1909 1910 #include <ddb/ddb.h> 1911 1912 static int 1913 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1914 { 1915 vm_map_t tmpm; 1916 vm_map_entry_t tmpe; 1917 vm_object_t obj; 1918 int entcount; 1919 1920 if (map == 0) 1921 return 0; 1922 1923 if (entry == 0) { 1924 tmpe = map->header.next; 1925 entcount = map->nentries; 1926 while (entcount-- && (tmpe != &map->header)) { 1927 if (_vm_object_in_map(map, object, tmpe)) { 1928 return 1; 1929 } 1930 tmpe = tmpe->next; 1931 } 1932 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1933 tmpm = entry->object.sub_map; 1934 tmpe = tmpm->header.next; 1935 entcount = tmpm->nentries; 1936 while (entcount-- && tmpe != &tmpm->header) { 1937 if (_vm_object_in_map(tmpm, object, tmpe)) { 1938 return 1; 1939 } 1940 tmpe = tmpe->next; 1941 } 1942 } else if ((obj = entry->object.vm_object) != NULL) { 1943 for (; obj; obj = obj->backing_object) 1944 if (obj == object) { 1945 return 1; 1946 } 1947 } 1948 return 0; 1949 } 1950 1951 static int 1952 vm_object_in_map(vm_object_t object) 1953 { 1954 struct proc *p; 1955 1956 /* sx_slock(&allproc_lock); */ 1957 LIST_FOREACH(p, &allproc, p_list) { 1958 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1959 continue; 1960 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 1961 /* sx_sunlock(&allproc_lock); */ 1962 return 1; 1963 } 1964 } 1965 /* sx_sunlock(&allproc_lock); */ 1966 if (_vm_object_in_map(kernel_map, object, 0)) 1967 return 1; 1968 if (_vm_object_in_map(kmem_map, object, 0)) 1969 return 1; 1970 if (_vm_object_in_map(pager_map, object, 0)) 1971 return 1; 1972 if (_vm_object_in_map(buffer_map, object, 0)) 1973 return 1; 1974 return 0; 1975 } 1976 1977 DB_SHOW_COMMAND(vmochk, vm_object_check) 1978 { 1979 vm_object_t object; 1980 1981 /* 1982 * make sure that internal objs are in a map somewhere 1983 * and none have zero ref counts. 1984 */ 1985 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1986 if (object->handle == NULL && 1987 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1988 if (object->ref_count == 0) { 1989 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1990 (long)object->size); 1991 } 1992 if (!vm_object_in_map(object)) { 1993 db_printf( 1994 "vmochk: internal obj is not in a map: " 1995 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 1996 object->ref_count, (u_long)object->size, 1997 (u_long)object->size, 1998 (void *)object->backing_object); 1999 } 2000 } 2001 } 2002 } 2003 2004 /* 2005 * vm_object_print: [ debug ] 2006 */ 2007 DB_SHOW_COMMAND(object, vm_object_print_static) 2008 { 2009 /* XXX convert args. */ 2010 vm_object_t object = (vm_object_t)addr; 2011 boolean_t full = have_addr; 2012 2013 vm_page_t p; 2014 2015 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2016 #define count was_count 2017 2018 int count; 2019 2020 if (object == NULL) 2021 return; 2022 2023 db_iprintf( 2024 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n", 2025 object, (int)object->type, (uintmax_t)object->size, 2026 object->resident_page_count, object->ref_count, object->flags); 2027 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2028 object->shadow_count, 2029 object->backing_object ? object->backing_object->ref_count : 0, 2030 object->backing_object, (uintmax_t)object->backing_object_offset); 2031 2032 if (!full) 2033 return; 2034 2035 db_indent += 2; 2036 count = 0; 2037 TAILQ_FOREACH(p, &object->memq, listq) { 2038 if (count == 0) 2039 db_iprintf("memory:="); 2040 else if (count == 6) { 2041 db_printf("\n"); 2042 db_iprintf(" ..."); 2043 count = 0; 2044 } else 2045 db_printf(","); 2046 count++; 2047 2048 db_printf("(off=0x%jx,page=0x%jx)", 2049 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2050 } 2051 if (count != 0) 2052 db_printf("\n"); 2053 db_indent -= 2; 2054 } 2055 2056 /* XXX. */ 2057 #undef count 2058 2059 /* XXX need this non-static entry for calling from vm_map_print. */ 2060 void 2061 vm_object_print( 2062 /* db_expr_t */ long addr, 2063 boolean_t have_addr, 2064 /* db_expr_t */ long count, 2065 char *modif) 2066 { 2067 vm_object_print_static(addr, have_addr, count, modif); 2068 } 2069 2070 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2071 { 2072 vm_object_t object; 2073 int nl = 0; 2074 int c; 2075 2076 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2077 vm_pindex_t idx, fidx; 2078 vm_pindex_t osize; 2079 vm_paddr_t pa = -1, padiff; 2080 int rcount; 2081 vm_page_t m; 2082 2083 db_printf("new object: %p\n", (void *)object); 2084 if (nl > 18) { 2085 c = cngetc(); 2086 if (c != ' ') 2087 return; 2088 nl = 0; 2089 } 2090 nl++; 2091 rcount = 0; 2092 fidx = 0; 2093 osize = object->size; 2094 if (osize > 128) 2095 osize = 128; 2096 for (idx = 0; idx < osize; idx++) { 2097 m = vm_page_lookup(object, idx); 2098 if (m == NULL) { 2099 if (rcount) { 2100 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2101 (long)fidx, rcount, (long)pa); 2102 if (nl > 18) { 2103 c = cngetc(); 2104 if (c != ' ') 2105 return; 2106 nl = 0; 2107 } 2108 nl++; 2109 rcount = 0; 2110 } 2111 continue; 2112 } 2113 2114 2115 if (rcount && 2116 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2117 ++rcount; 2118 continue; 2119 } 2120 if (rcount) { 2121 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 2122 padiff >>= PAGE_SHIFT; 2123 padiff &= PQ_L2_MASK; 2124 if (padiff == 0) { 2125 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 2126 ++rcount; 2127 continue; 2128 } 2129 db_printf(" index(%ld)run(%d)pa(0x%lx)", 2130 (long)fidx, rcount, (long)pa); 2131 db_printf("pd(%ld)\n", (long)padiff); 2132 if (nl > 18) { 2133 c = cngetc(); 2134 if (c != ' ') 2135 return; 2136 nl = 0; 2137 } 2138 nl++; 2139 } 2140 fidx = idx; 2141 pa = VM_PAGE_TO_PHYS(m); 2142 rcount = 1; 2143 } 2144 if (rcount) { 2145 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2146 (long)fidx, rcount, (long)pa); 2147 if (nl > 18) { 2148 c = cngetc(); 2149 if (c != ' ') 2150 return; 2151 nl = 0; 2152 } 2153 nl++; 2154 } 2155 } 2156 } 2157 #endif /* DDB */ 2158