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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94 37 * 38 * 39 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 40 * All rights reserved. 41 * 42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young 43 * 44 * Permission to use, copy, modify and distribute this software and 45 * its documentation is hereby granted, provided that both the copyright 46 * notice and this permission notice appear in all copies of the 47 * software, derivative works or modified versions, and any portions 48 * thereof, and that both notices appear in supporting documentation. 49 * 50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 53 * 54 * Carnegie Mellon requests users of this software to return to 55 * 56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 57 * School of Computer Science 58 * Carnegie Mellon University 59 * Pittsburgh PA 15213-3890 60 * 61 * any improvements or extensions that they make and grant Carnegie the 62 * rights to redistribute these changes. 63 */ 64 65 /* 66 * Virtual memory object module. 67 */ 68 69 #include <sys/cdefs.h> 70 __FBSDID("$FreeBSD$"); 71 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/lock.h> 75 #include <sys/mman.h> 76 #include <sys/mount.h> 77 #include <sys/kernel.h> 78 #include <sys/sysctl.h> 79 #include <sys/mutex.h> 80 #include <sys/proc.h> /* for curproc, pageproc */ 81 #include <sys/socket.h> 82 #include <sys/vnode.h> 83 #include <sys/vmmeter.h> 84 #include <sys/sx.h> 85 86 #include <vm/vm.h> 87 #include <vm/vm_param.h> 88 #include <vm/pmap.h> 89 #include <vm/vm_map.h> 90 #include <vm/vm_object.h> 91 #include <vm/vm_page.h> 92 #include <vm/vm_pageout.h> 93 #include <vm/vm_pager.h> 94 #include <vm/swap_pager.h> 95 #include <vm/vm_kern.h> 96 #include <vm/vm_extern.h> 97 #include <vm/uma.h> 98 99 #define EASY_SCAN_FACTOR 8 100 101 #define MSYNC_FLUSH_HARDSEQ 0x01 102 #define MSYNC_FLUSH_SOFTSEQ 0x02 103 104 /* 105 * msync / VM object flushing optimizations 106 */ 107 static int msync_flush_flags = MSYNC_FLUSH_HARDSEQ | MSYNC_FLUSH_SOFTSEQ; 108 SYSCTL_INT(_vm, OID_AUTO, msync_flush_flags, 109 CTLFLAG_RW, &msync_flush_flags, 0, ""); 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); 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); 238 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 239 kernel_object); 240 241 /* 242 * The kmem object's mutex is given a unique name, instead of 243 * "vm object", to avoid false reports of lock-order reversal 244 * with a system map mutex. 245 */ 246 mtx_init(VM_OBJECT_MTX(kmem_object), "kmem object", NULL, MTX_DEF); 247 _vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS), 248 kmem_object); 249 250 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 251 #ifdef INVARIANTS 252 vm_object_zdtor, 253 #else 254 NULL, 255 #endif 256 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 257 uma_prealloc(obj_zone, VM_OBJECTS_INIT); 258 } 259 260 void 261 vm_object_clear_flag(vm_object_t object, u_short bits) 262 { 263 264 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 265 object->flags &= ~bits; 266 } 267 268 void 269 vm_object_pip_add(vm_object_t object, short i) 270 { 271 272 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 273 object->paging_in_progress += i; 274 } 275 276 void 277 vm_object_pip_subtract(vm_object_t object, short i) 278 { 279 280 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 281 object->paging_in_progress -= i; 282 } 283 284 void 285 vm_object_pip_wakeup(vm_object_t object) 286 { 287 288 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 289 object->paging_in_progress--; 290 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 291 vm_object_clear_flag(object, OBJ_PIPWNT); 292 wakeup(object); 293 } 294 } 295 296 void 297 vm_object_pip_wakeupn(vm_object_t object, short i) 298 { 299 300 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 301 if (i) 302 object->paging_in_progress -= i; 303 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 304 vm_object_clear_flag(object, OBJ_PIPWNT); 305 wakeup(object); 306 } 307 } 308 309 void 310 vm_object_pip_wait(vm_object_t object, char *waitid) 311 { 312 313 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 314 while (object->paging_in_progress) { 315 object->flags |= OBJ_PIPWNT; 316 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 317 } 318 } 319 320 /* 321 * vm_object_allocate_wait 322 * 323 * Return a new object with the given size, and give the user the 324 * option of waiting for it to complete or failing if the needed 325 * memory isn't available. 326 */ 327 vm_object_t 328 vm_object_allocate_wait(objtype_t type, vm_pindex_t size, int flags) 329 { 330 vm_object_t result; 331 332 result = (vm_object_t) uma_zalloc(obj_zone, flags); 333 334 if (result != NULL) 335 _vm_object_allocate(type, size, result); 336 337 return (result); 338 } 339 340 /* 341 * vm_object_allocate: 342 * 343 * Returns a new object with the given size. 344 */ 345 vm_object_t 346 vm_object_allocate(objtype_t type, vm_pindex_t size) 347 { 348 return(vm_object_allocate_wait(type, size, M_WAITOK)); 349 } 350 351 352 /* 353 * vm_object_reference: 354 * 355 * Gets another reference to the given object. Note: OBJ_DEAD 356 * objects can be referenced during final cleaning. 357 */ 358 void 359 vm_object_reference(vm_object_t object) 360 { 361 struct vnode *vp; 362 int flags; 363 364 if (object == NULL) 365 return; 366 VM_OBJECT_LOCK(object); 367 object->ref_count++; 368 if (object->type == OBJT_VNODE) { 369 vp = object->handle; 370 VI_LOCK(vp); 371 VM_OBJECT_UNLOCK(object); 372 for (flags = LK_INTERLOCK; vget(vp, flags, curthread); 373 flags = 0) 374 printf("vm_object_reference: delay in vget\n"); 375 } else 376 VM_OBJECT_UNLOCK(object); 377 } 378 379 /* 380 * vm_object_reference_locked: 381 * 382 * Gets another reference to the given object. 383 * 384 * The object must be locked. 385 */ 386 void 387 vm_object_reference_locked(vm_object_t object) 388 { 389 struct vnode *vp; 390 391 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 392 KASSERT((object->flags & OBJ_DEAD) == 0, 393 ("vm_object_reference_locked: dead object referenced")); 394 object->ref_count++; 395 if (object->type == OBJT_VNODE) { 396 vp = object->handle; 397 vref(vp); 398 } 399 } 400 401 /* 402 * Handle deallocating an object of type OBJT_VNODE. 403 */ 404 void 405 vm_object_vndeallocate(vm_object_t object) 406 { 407 struct vnode *vp = (struct vnode *) object->handle; 408 409 GIANT_REQUIRED; 410 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 411 KASSERT(object->type == OBJT_VNODE, 412 ("vm_object_vndeallocate: not a vnode object")); 413 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 414 #ifdef INVARIANTS 415 if (object->ref_count == 0) { 416 vprint("vm_object_vndeallocate", vp); 417 panic("vm_object_vndeallocate: bad object reference count"); 418 } 419 #endif 420 421 object->ref_count--; 422 if (object->ref_count == 0) { 423 mp_fixme("Unlocked vflag access."); 424 vp->v_vflag &= ~VV_TEXT; 425 } 426 VM_OBJECT_UNLOCK(object); 427 /* 428 * vrele may need a vop lock 429 */ 430 vrele(vp); 431 } 432 433 /* 434 * vm_object_deallocate: 435 * 436 * Release a reference to the specified object, 437 * gained either through a vm_object_allocate 438 * or a vm_object_reference call. When all references 439 * are gone, storage associated with this object 440 * may be relinquished. 441 * 442 * No object may be locked. 443 */ 444 void 445 vm_object_deallocate(vm_object_t object) 446 { 447 vm_object_t temp; 448 449 while (object != NULL) { 450 /* 451 * In general, the object should be locked when working with 452 * its type. In this case, in order to maintain proper lock 453 * ordering, an exception is possible because a vnode-backed 454 * object never changes its type. 455 */ 456 if (object->type == OBJT_VNODE) 457 mtx_lock(&Giant); 458 VM_OBJECT_LOCK(object); 459 if (object->type == OBJT_VNODE) { 460 vm_object_vndeallocate(object); 461 mtx_unlock(&Giant); 462 return; 463 } 464 465 KASSERT(object->ref_count != 0, 466 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 467 468 /* 469 * If the reference count goes to 0 we start calling 470 * vm_object_terminate() on the object chain. 471 * A ref count of 1 may be a special case depending on the 472 * shadow count being 0 or 1. 473 */ 474 object->ref_count--; 475 if (object->ref_count > 1) { 476 VM_OBJECT_UNLOCK(object); 477 return; 478 } else if (object->ref_count == 1) { 479 if (object->shadow_count == 0) { 480 vm_object_set_flag(object, OBJ_ONEMAPPING); 481 } else if ((object->shadow_count == 1) && 482 (object->handle == NULL) && 483 (object->type == OBJT_DEFAULT || 484 object->type == OBJT_SWAP)) { 485 vm_object_t robject; 486 487 robject = LIST_FIRST(&object->shadow_head); 488 KASSERT(robject != NULL, 489 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 490 object->ref_count, 491 object->shadow_count)); 492 if (!VM_OBJECT_TRYLOCK(robject)) { 493 /* 494 * Avoid a potential deadlock. 495 */ 496 object->ref_count++; 497 VM_OBJECT_UNLOCK(object); 498 continue; 499 } 500 if ((robject->handle == NULL) && 501 (robject->type == OBJT_DEFAULT || 502 robject->type == OBJT_SWAP)) { 503 504 robject->ref_count++; 505 retry: 506 if (robject->paging_in_progress) { 507 VM_OBJECT_UNLOCK(object); 508 vm_object_pip_wait(robject, 509 "objde1"); 510 VM_OBJECT_LOCK(object); 511 goto retry; 512 } else if (object->paging_in_progress) { 513 VM_OBJECT_UNLOCK(robject); 514 object->flags |= OBJ_PIPWNT; 515 msleep(object, 516 VM_OBJECT_MTX(object), 517 PDROP | PVM, "objde2", 0); 518 VM_OBJECT_LOCK(robject); 519 VM_OBJECT_LOCK(object); 520 goto retry; 521 } 522 VM_OBJECT_UNLOCK(object); 523 if (robject->ref_count == 1) { 524 robject->ref_count--; 525 object = robject; 526 goto doterm; 527 } 528 object = robject; 529 vm_object_collapse(object); 530 VM_OBJECT_UNLOCK(object); 531 continue; 532 } 533 VM_OBJECT_UNLOCK(robject); 534 } 535 VM_OBJECT_UNLOCK(object); 536 return; 537 } 538 doterm: 539 temp = object->backing_object; 540 if (temp != NULL) { 541 VM_OBJECT_LOCK(temp); 542 LIST_REMOVE(object, shadow_list); 543 temp->shadow_count--; 544 temp->generation++; 545 VM_OBJECT_UNLOCK(temp); 546 object->backing_object = NULL; 547 } 548 /* 549 * Don't double-terminate, we could be in a termination 550 * recursion due to the terminate having to sync data 551 * to disk. 552 */ 553 if ((object->flags & OBJ_DEAD) == 0) 554 vm_object_terminate(object); 555 else 556 VM_OBJECT_UNLOCK(object); 557 object = temp; 558 } 559 } 560 561 /* 562 * vm_object_terminate actually destroys the specified object, freeing 563 * up all previously used resources. 564 * 565 * The object must be locked. 566 * This routine may block. 567 */ 568 void 569 vm_object_terminate(vm_object_t object) 570 { 571 vm_page_t p; 572 int s; 573 574 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 575 576 /* 577 * Make sure no one uses us. 578 */ 579 vm_object_set_flag(object, OBJ_DEAD); 580 581 /* 582 * wait for the pageout daemon to be done with the object 583 */ 584 vm_object_pip_wait(object, "objtrm"); 585 586 KASSERT(!object->paging_in_progress, 587 ("vm_object_terminate: pageout in progress")); 588 589 /* 590 * Clean and free the pages, as appropriate. All references to the 591 * object are gone, so we don't need to lock it. 592 */ 593 if (object->type == OBJT_VNODE) { 594 struct vnode *vp = (struct vnode *)object->handle; 595 596 /* 597 * Clean pages and flush buffers. 598 */ 599 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 600 VM_OBJECT_UNLOCK(object); 601 602 vinvalbuf(vp, V_SAVE, NOCRED, NULL, 0, 0); 603 604 VM_OBJECT_LOCK(object); 605 } 606 607 KASSERT(object->ref_count == 0, 608 ("vm_object_terminate: object with references, ref_count=%d", 609 object->ref_count)); 610 611 /* 612 * Now free any remaining pages. For internal objects, this also 613 * removes them from paging queues. Don't free wired pages, just 614 * remove them from the object. 615 */ 616 s = splvm(); 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 splx(s); 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 s; 863 int maxf; 864 int chkb; 865 int maxb; 866 int i; 867 vm_pindex_t pi; 868 vm_page_t maf[vm_pageout_page_count]; 869 vm_page_t mab[vm_pageout_page_count]; 870 vm_page_t ma[vm_pageout_page_count]; 871 872 s = splvm(); 873 mtx_assert(&vm_page_queue_mtx, MA_OWNED); 874 pi = p->pindex; 875 while (vm_page_sleep_if_busy(p, TRUE, "vpcwai")) { 876 vm_page_lock_queues(); 877 if (object->generation != curgeneration) { 878 splx(s); 879 return(0); 880 } 881 } 882 maxf = 0; 883 for(i = 1; i < vm_pageout_page_count; i++) { 884 vm_page_t tp; 885 886 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 887 if ((tp->flags & PG_BUSY) || 888 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 889 (tp->flags & PG_CLEANCHK) == 0) || 890 (tp->busy != 0)) 891 break; 892 if((tp->queue - tp->pc) == PQ_CACHE) { 893 vm_page_flag_clear(tp, PG_CLEANCHK); 894 break; 895 } 896 vm_page_test_dirty(tp); 897 if ((tp->dirty & tp->valid) == 0) { 898 vm_page_flag_clear(tp, PG_CLEANCHK); 899 break; 900 } 901 maf[ i - 1 ] = tp; 902 maxf++; 903 continue; 904 } 905 break; 906 } 907 908 maxb = 0; 909 chkb = vm_pageout_page_count - maxf; 910 if (chkb) { 911 for(i = 1; i < chkb;i++) { 912 vm_page_t tp; 913 914 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 915 if ((tp->flags & PG_BUSY) || 916 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 917 (tp->flags & PG_CLEANCHK) == 0) || 918 (tp->busy != 0)) 919 break; 920 if ((tp->queue - tp->pc) == PQ_CACHE) { 921 vm_page_flag_clear(tp, PG_CLEANCHK); 922 break; 923 } 924 vm_page_test_dirty(tp); 925 if ((tp->dirty & tp->valid) == 0) { 926 vm_page_flag_clear(tp, PG_CLEANCHK); 927 break; 928 } 929 mab[ i - 1 ] = tp; 930 maxb++; 931 continue; 932 } 933 break; 934 } 935 } 936 937 for(i = 0; i < maxb; i++) { 938 int index = (maxb - i) - 1; 939 ma[index] = mab[i]; 940 vm_page_flag_clear(ma[index], PG_CLEANCHK); 941 } 942 vm_page_flag_clear(p, PG_CLEANCHK); 943 ma[maxb] = p; 944 for(i = 0; i < maxf; i++) { 945 int index = (maxb + i) + 1; 946 ma[index] = maf[i]; 947 vm_page_flag_clear(ma[index], PG_CLEANCHK); 948 } 949 runlen = maxb + maxf + 1; 950 951 splx(s); 952 vm_pageout_flush(ma, runlen, pagerflags); 953 for (i = 0; i < runlen; i++) { 954 if (ma[i]->valid & ma[i]->dirty) { 955 pmap_page_protect(ma[i], VM_PROT_READ); 956 vm_page_flag_set(ma[i], PG_CLEANCHK); 957 958 /* 959 * maxf will end up being the actual number of pages 960 * we wrote out contiguously, non-inclusive of the 961 * first page. We do not count look-behind pages. 962 */ 963 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 964 maxf = i - maxb - 1; 965 } 966 } 967 return(maxf + 1); 968 } 969 970 /* 971 * Note that there is absolutely no sense in writing out 972 * anonymous objects, so we track down the vnode object 973 * to write out. 974 * We invalidate (remove) all pages from the address space 975 * for semantic correctness. 976 * 977 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 978 * may start out with a NULL object. 979 */ 980 void 981 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 982 boolean_t syncio, boolean_t invalidate) 983 { 984 vm_object_t backing_object; 985 struct vnode *vp; 986 int flags; 987 988 if (object == NULL) 989 return; 990 VM_OBJECT_LOCK(object); 991 while ((backing_object = object->backing_object) != NULL) { 992 VM_OBJECT_LOCK(backing_object); 993 VM_OBJECT_UNLOCK(object); 994 object = backing_object; 995 offset += object->backing_object_offset; 996 if (object->size < OFF_TO_IDX(offset + size)) 997 size = IDX_TO_OFF(object->size) - offset; 998 } 999 /* 1000 * Flush pages if writing is allowed, invalidate them 1001 * if invalidation requested. Pages undergoing I/O 1002 * will be ignored by vm_object_page_remove(). 1003 * 1004 * We cannot lock the vnode and then wait for paging 1005 * to complete without deadlocking against vm_fault. 1006 * Instead we simply call vm_object_page_remove() and 1007 * allow it to block internally on a page-by-page 1008 * basis when it encounters pages undergoing async 1009 * I/O. 1010 */ 1011 if (object->type == OBJT_VNODE && 1012 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1013 vp = object->handle; 1014 VM_OBJECT_UNLOCK(object); 1015 mtx_lock(&Giant); 1016 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 1017 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1018 flags |= invalidate ? OBJPC_INVAL : 0; 1019 VM_OBJECT_LOCK(object); 1020 vm_object_page_clean(object, 1021 OFF_TO_IDX(offset), 1022 OFF_TO_IDX(offset + size + PAGE_MASK), 1023 flags); 1024 VM_OBJECT_UNLOCK(object); 1025 VOP_UNLOCK(vp, 0, curthread); 1026 mtx_unlock(&Giant); 1027 VM_OBJECT_LOCK(object); 1028 } 1029 if ((object->type == OBJT_VNODE || 1030 object->type == OBJT_DEVICE) && invalidate) { 1031 vm_object_page_remove(object, 1032 OFF_TO_IDX(offset), 1033 OFF_TO_IDX(offset + size + PAGE_MASK), 1034 FALSE); 1035 } 1036 VM_OBJECT_UNLOCK(object); 1037 } 1038 1039 /* 1040 * vm_object_madvise: 1041 * 1042 * Implements the madvise function at the object/page level. 1043 * 1044 * MADV_WILLNEED (any object) 1045 * 1046 * Activate the specified pages if they are resident. 1047 * 1048 * MADV_DONTNEED (any object) 1049 * 1050 * Deactivate the specified pages if they are resident. 1051 * 1052 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1053 * OBJ_ONEMAPPING only) 1054 * 1055 * Deactivate and clean the specified pages if they are 1056 * resident. This permits the process to reuse the pages 1057 * without faulting or the kernel to reclaim the pages 1058 * without I/O. 1059 */ 1060 void 1061 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1062 { 1063 vm_pindex_t end, tpindex; 1064 vm_object_t backing_object, tobject; 1065 vm_page_t m; 1066 1067 if (object == NULL) 1068 return; 1069 end = pindex + count; 1070 /* 1071 * Locate and adjust resident pages 1072 */ 1073 for (; pindex < end; pindex += 1) { 1074 relookup: 1075 tobject = object; 1076 tpindex = pindex; 1077 VM_OBJECT_LOCK(tobject); 1078 shadowlookup: 1079 /* 1080 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1081 * and those pages must be OBJ_ONEMAPPING. 1082 */ 1083 if (advise == MADV_FREE) { 1084 if ((tobject->type != OBJT_DEFAULT && 1085 tobject->type != OBJT_SWAP) || 1086 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1087 goto unlock_tobject; 1088 } 1089 } 1090 m = vm_page_lookup(tobject, tpindex); 1091 if (m == NULL) { 1092 /* 1093 * There may be swap even if there is no backing page 1094 */ 1095 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1096 swap_pager_freespace(tobject, tpindex, 1); 1097 /* 1098 * next object 1099 */ 1100 backing_object = tobject->backing_object; 1101 if (backing_object == NULL) 1102 goto unlock_tobject; 1103 VM_OBJECT_LOCK(backing_object); 1104 VM_OBJECT_UNLOCK(tobject); 1105 tobject = backing_object; 1106 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1107 goto shadowlookup; 1108 } 1109 /* 1110 * If the page is busy or not in a normal active state, 1111 * we skip it. If the page is not managed there are no 1112 * page queues to mess with. Things can break if we mess 1113 * with pages in any of the below states. 1114 */ 1115 vm_page_lock_queues(); 1116 if (m->hold_count || 1117 m->wire_count || 1118 (m->flags & PG_UNMANAGED) || 1119 m->valid != VM_PAGE_BITS_ALL) { 1120 vm_page_unlock_queues(); 1121 goto unlock_tobject; 1122 } 1123 if (vm_page_sleep_if_busy(m, TRUE, "madvpo")) { 1124 VM_OBJECT_UNLOCK(tobject); 1125 goto relookup; 1126 } 1127 if (advise == MADV_WILLNEED) { 1128 vm_page_activate(m); 1129 } else if (advise == MADV_DONTNEED) { 1130 vm_page_dontneed(m); 1131 } else if (advise == MADV_FREE) { 1132 /* 1133 * Mark the page clean. This will allow the page 1134 * to be freed up by the system. However, such pages 1135 * are often reused quickly by malloc()/free() 1136 * so we do not do anything that would cause 1137 * a page fault if we can help it. 1138 * 1139 * Specifically, we do not try to actually free 1140 * the page now nor do we try to put it in the 1141 * cache (which would cause a page fault on reuse). 1142 * 1143 * But we do make the page is freeable as we 1144 * can without actually taking the step of unmapping 1145 * it. 1146 */ 1147 pmap_clear_modify(m); 1148 m->dirty = 0; 1149 m->act_count = 0; 1150 vm_page_dontneed(m); 1151 } 1152 vm_page_unlock_queues(); 1153 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1154 swap_pager_freespace(tobject, tpindex, 1); 1155 unlock_tobject: 1156 VM_OBJECT_UNLOCK(tobject); 1157 } 1158 } 1159 1160 /* 1161 * vm_object_shadow: 1162 * 1163 * Create a new object which is backed by the 1164 * specified existing object range. The source 1165 * object reference is deallocated. 1166 * 1167 * The new object and offset into that object 1168 * are returned in the source parameters. 1169 */ 1170 void 1171 vm_object_shadow( 1172 vm_object_t *object, /* IN/OUT */ 1173 vm_ooffset_t *offset, /* IN/OUT */ 1174 vm_size_t length) 1175 { 1176 vm_object_t source; 1177 vm_object_t result; 1178 1179 source = *object; 1180 1181 /* 1182 * Don't create the new object if the old object isn't shared. 1183 */ 1184 if (source != NULL) { 1185 VM_OBJECT_LOCK(source); 1186 if (source->ref_count == 1 && 1187 source->handle == NULL && 1188 (source->type == OBJT_DEFAULT || 1189 source->type == OBJT_SWAP)) { 1190 VM_OBJECT_UNLOCK(source); 1191 return; 1192 } 1193 VM_OBJECT_UNLOCK(source); 1194 } 1195 1196 /* 1197 * Allocate a new object with the given length. 1198 */ 1199 result = vm_object_allocate(OBJT_DEFAULT, length); 1200 1201 /* 1202 * The new object shadows the source object, adding a reference to it. 1203 * Our caller changes his reference to point to the new object, 1204 * removing a reference to the source object. Net result: no change 1205 * of reference count. 1206 * 1207 * Try to optimize the result object's page color when shadowing 1208 * in order to maintain page coloring consistency in the combined 1209 * shadowed object. 1210 */ 1211 result->backing_object = source; 1212 if (source != NULL) { 1213 VM_OBJECT_LOCK(source); 1214 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1215 source->shadow_count++; 1216 source->generation++; 1217 if (length < source->size) 1218 length = source->size; 1219 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 || 1220 source->generation > 1) 1221 length = PQ_L2_SIZE / 3 + PQ_PRIME1; 1222 result->pg_color = (source->pg_color + 1223 length * source->generation) & PQ_L2_MASK; 1224 VM_OBJECT_UNLOCK(source); 1225 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & 1226 PQ_L2_MASK; 1227 } 1228 1229 /* 1230 * Store the offset into the source object, and fix up the offset into 1231 * the new object. 1232 */ 1233 result->backing_object_offset = *offset; 1234 1235 /* 1236 * Return the new things 1237 */ 1238 *offset = 0; 1239 *object = result; 1240 } 1241 1242 /* 1243 * vm_object_split: 1244 * 1245 * Split the pages in a map entry into a new object. This affords 1246 * easier removal of unused pages, and keeps object inheritance from 1247 * being a negative impact on memory usage. 1248 */ 1249 void 1250 vm_object_split(vm_map_entry_t entry) 1251 { 1252 vm_page_t m; 1253 vm_object_t orig_object, new_object, source; 1254 vm_pindex_t offidxstart, offidxend; 1255 vm_size_t idx, size; 1256 1257 orig_object = entry->object.vm_object; 1258 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1259 return; 1260 if (orig_object->ref_count <= 1) 1261 return; 1262 VM_OBJECT_UNLOCK(orig_object); 1263 1264 offidxstart = OFF_TO_IDX(entry->offset); 1265 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); 1266 size = offidxend - offidxstart; 1267 1268 /* 1269 * If swap_pager_copy() is later called, it will convert new_object 1270 * into a swap object. 1271 */ 1272 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1273 1274 VM_OBJECT_LOCK(new_object); 1275 VM_OBJECT_LOCK(orig_object); 1276 source = orig_object->backing_object; 1277 if (source != NULL) { 1278 VM_OBJECT_LOCK(source); 1279 LIST_INSERT_HEAD(&source->shadow_head, 1280 new_object, shadow_list); 1281 source->shadow_count++; 1282 source->generation++; 1283 vm_object_reference_locked(source); /* for new_object */ 1284 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1285 VM_OBJECT_UNLOCK(source); 1286 new_object->backing_object_offset = 1287 orig_object->backing_object_offset + entry->offset; 1288 new_object->backing_object = source; 1289 } 1290 for (idx = 0; idx < size; idx++) { 1291 retry: 1292 m = vm_page_lookup(orig_object, offidxstart + idx); 1293 if (m == NULL) 1294 continue; 1295 1296 /* 1297 * We must wait for pending I/O to complete before we can 1298 * rename the page. 1299 * 1300 * We do not have to VM_PROT_NONE the page as mappings should 1301 * not be changed by this operation. 1302 */ 1303 vm_page_lock_queues(); 1304 if ((m->flags & PG_BUSY) || m->busy) { 1305 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1306 VM_OBJECT_UNLOCK(orig_object); 1307 VM_OBJECT_UNLOCK(new_object); 1308 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0); 1309 VM_OBJECT_LOCK(new_object); 1310 VM_OBJECT_LOCK(orig_object); 1311 goto retry; 1312 } 1313 vm_page_busy(m); 1314 vm_page_rename(m, new_object, idx); 1315 /* page automatically made dirty by rename and cache handled */ 1316 vm_page_busy(m); 1317 vm_page_unlock_queues(); 1318 } 1319 if (orig_object->type == OBJT_SWAP) { 1320 /* 1321 * swap_pager_copy() can sleep, in which case the orig_object's 1322 * and new_object's locks are released and reacquired. 1323 */ 1324 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1325 } 1326 VM_OBJECT_UNLOCK(orig_object); 1327 vm_page_lock_queues(); 1328 TAILQ_FOREACH(m, &new_object->memq, listq) 1329 vm_page_wakeup(m); 1330 vm_page_unlock_queues(); 1331 VM_OBJECT_UNLOCK(new_object); 1332 entry->object.vm_object = new_object; 1333 entry->offset = 0LL; 1334 vm_object_deallocate(orig_object); 1335 VM_OBJECT_LOCK(new_object); 1336 } 1337 1338 #define OBSC_TEST_ALL_SHADOWED 0x0001 1339 #define OBSC_COLLAPSE_NOWAIT 0x0002 1340 #define OBSC_COLLAPSE_WAIT 0x0004 1341 1342 static int 1343 vm_object_backing_scan(vm_object_t object, int op) 1344 { 1345 int s; 1346 int r = 1; 1347 vm_page_t p; 1348 vm_object_t backing_object; 1349 vm_pindex_t backing_offset_index; 1350 1351 s = splvm(); 1352 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1353 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1354 1355 backing_object = object->backing_object; 1356 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1357 1358 /* 1359 * Initial conditions 1360 */ 1361 if (op & OBSC_TEST_ALL_SHADOWED) { 1362 /* 1363 * We do not want to have to test for the existence of 1364 * swap pages in the backing object. XXX but with the 1365 * new swapper this would be pretty easy to do. 1366 * 1367 * XXX what about anonymous MAP_SHARED memory that hasn't 1368 * been ZFOD faulted yet? If we do not test for this, the 1369 * shadow test may succeed! XXX 1370 */ 1371 if (backing_object->type != OBJT_DEFAULT) { 1372 splx(s); 1373 return (0); 1374 } 1375 } 1376 if (op & OBSC_COLLAPSE_WAIT) { 1377 vm_object_set_flag(backing_object, OBJ_DEAD); 1378 } 1379 1380 /* 1381 * Our scan 1382 */ 1383 p = TAILQ_FIRST(&backing_object->memq); 1384 while (p) { 1385 vm_page_t next = TAILQ_NEXT(p, listq); 1386 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1387 1388 if (op & OBSC_TEST_ALL_SHADOWED) { 1389 vm_page_t pp; 1390 1391 /* 1392 * Ignore pages outside the parent object's range 1393 * and outside the parent object's mapping of the 1394 * backing object. 1395 * 1396 * note that we do not busy the backing object's 1397 * page. 1398 */ 1399 if ( 1400 p->pindex < backing_offset_index || 1401 new_pindex >= object->size 1402 ) { 1403 p = next; 1404 continue; 1405 } 1406 1407 /* 1408 * See if the parent has the page or if the parent's 1409 * object pager has the page. If the parent has the 1410 * page but the page is not valid, the parent's 1411 * object pager must have the page. 1412 * 1413 * If this fails, the parent does not completely shadow 1414 * the object and we might as well give up now. 1415 */ 1416 1417 pp = vm_page_lookup(object, new_pindex); 1418 if ( 1419 (pp == NULL || pp->valid == 0) && 1420 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1421 ) { 1422 r = 0; 1423 break; 1424 } 1425 } 1426 1427 /* 1428 * Check for busy page 1429 */ 1430 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1431 vm_page_t pp; 1432 1433 vm_page_lock_queues(); 1434 if (op & OBSC_COLLAPSE_NOWAIT) { 1435 if ((p->flags & PG_BUSY) || 1436 !p->valid || 1437 p->hold_count || 1438 p->wire_count || 1439 p->busy) { 1440 vm_page_unlock_queues(); 1441 p = next; 1442 continue; 1443 } 1444 } else if (op & OBSC_COLLAPSE_WAIT) { 1445 if ((p->flags & PG_BUSY) || p->busy) { 1446 vm_page_flag_set(p, 1447 PG_WANTED | PG_REFERENCED); 1448 VM_OBJECT_UNLOCK(backing_object); 1449 VM_OBJECT_UNLOCK(object); 1450 msleep(p, &vm_page_queue_mtx, 1451 PDROP | PVM, "vmocol", 0); 1452 VM_OBJECT_LOCK(object); 1453 VM_OBJECT_LOCK(backing_object); 1454 /* 1455 * If we slept, anything could have 1456 * happened. Since the object is 1457 * marked dead, the backing offset 1458 * should not have changed so we 1459 * just restart our scan. 1460 */ 1461 p = TAILQ_FIRST(&backing_object->memq); 1462 continue; 1463 } 1464 } 1465 1466 /* 1467 * Busy the page 1468 */ 1469 vm_page_busy(p); 1470 vm_page_unlock_queues(); 1471 1472 KASSERT( 1473 p->object == backing_object, 1474 ("vm_object_qcollapse(): object mismatch") 1475 ); 1476 1477 /* 1478 * Destroy any associated swap 1479 */ 1480 if (backing_object->type == OBJT_SWAP) { 1481 swap_pager_freespace( 1482 backing_object, 1483 p->pindex, 1484 1 1485 ); 1486 } 1487 1488 if ( 1489 p->pindex < backing_offset_index || 1490 new_pindex >= object->size 1491 ) { 1492 /* 1493 * Page is out of the parent object's range, we 1494 * can simply destroy it. 1495 */ 1496 vm_page_lock_queues(); 1497 pmap_remove_all(p); 1498 vm_page_free(p); 1499 vm_page_unlock_queues(); 1500 p = next; 1501 continue; 1502 } 1503 1504 pp = vm_page_lookup(object, new_pindex); 1505 if ( 1506 pp != NULL || 1507 vm_pager_has_page(object, new_pindex, NULL, NULL) 1508 ) { 1509 /* 1510 * page already exists in parent OR swap exists 1511 * for this location in the parent. Destroy 1512 * the original page from the backing object. 1513 * 1514 * Leave the parent's page alone 1515 */ 1516 vm_page_lock_queues(); 1517 pmap_remove_all(p); 1518 vm_page_free(p); 1519 vm_page_unlock_queues(); 1520 p = next; 1521 continue; 1522 } 1523 1524 /* 1525 * Page does not exist in parent, rename the 1526 * page from the backing object to the main object. 1527 * 1528 * If the page was mapped to a process, it can remain 1529 * mapped through the rename. 1530 */ 1531 vm_page_lock_queues(); 1532 vm_page_rename(p, object, new_pindex); 1533 vm_page_unlock_queues(); 1534 /* page automatically made dirty by rename */ 1535 } 1536 p = next; 1537 } 1538 splx(s); 1539 return (r); 1540 } 1541 1542 1543 /* 1544 * this version of collapse allows the operation to occur earlier and 1545 * when paging_in_progress is true for an object... This is not a complete 1546 * operation, but should plug 99.9% of the rest of the leaks. 1547 */ 1548 static void 1549 vm_object_qcollapse(vm_object_t object) 1550 { 1551 vm_object_t backing_object = object->backing_object; 1552 1553 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1554 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1555 1556 if (backing_object->ref_count != 1) 1557 return; 1558 1559 backing_object->ref_count += 2; 1560 1561 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1562 1563 backing_object->ref_count -= 2; 1564 } 1565 1566 /* 1567 * vm_object_collapse: 1568 * 1569 * Collapse an object with the object backing it. 1570 * Pages in the backing object are moved into the 1571 * parent, and the backing object is deallocated. 1572 */ 1573 void 1574 vm_object_collapse(vm_object_t object) 1575 { 1576 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1577 1578 while (TRUE) { 1579 vm_object_t backing_object; 1580 1581 /* 1582 * Verify that the conditions are right for collapse: 1583 * 1584 * The object exists and the backing object exists. 1585 */ 1586 if ((backing_object = object->backing_object) == NULL) 1587 break; 1588 1589 /* 1590 * we check the backing object first, because it is most likely 1591 * not collapsable. 1592 */ 1593 VM_OBJECT_LOCK(backing_object); 1594 if (backing_object->handle != NULL || 1595 (backing_object->type != OBJT_DEFAULT && 1596 backing_object->type != OBJT_SWAP) || 1597 (backing_object->flags & OBJ_DEAD) || 1598 object->handle != NULL || 1599 (object->type != OBJT_DEFAULT && 1600 object->type != OBJT_SWAP) || 1601 (object->flags & OBJ_DEAD)) { 1602 VM_OBJECT_UNLOCK(backing_object); 1603 break; 1604 } 1605 1606 if ( 1607 object->paging_in_progress != 0 || 1608 backing_object->paging_in_progress != 0 1609 ) { 1610 vm_object_qcollapse(object); 1611 VM_OBJECT_UNLOCK(backing_object); 1612 break; 1613 } 1614 /* 1615 * We know that we can either collapse the backing object (if 1616 * the parent is the only reference to it) or (perhaps) have 1617 * the parent bypass the object if the parent happens to shadow 1618 * all the resident pages in the entire backing object. 1619 * 1620 * This is ignoring pager-backed pages such as swap pages. 1621 * vm_object_backing_scan fails the shadowing test in this 1622 * case. 1623 */ 1624 if (backing_object->ref_count == 1) { 1625 /* 1626 * If there is exactly one reference to the backing 1627 * object, we can collapse it into the parent. 1628 */ 1629 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1630 1631 /* 1632 * Move the pager from backing_object to object. 1633 */ 1634 if (backing_object->type == OBJT_SWAP) { 1635 /* 1636 * swap_pager_copy() can sleep, in which case 1637 * the backing_object's and object's locks are 1638 * released and reacquired. 1639 */ 1640 swap_pager_copy( 1641 backing_object, 1642 object, 1643 OFF_TO_IDX(object->backing_object_offset), TRUE); 1644 } 1645 /* 1646 * Object now shadows whatever backing_object did. 1647 * Note that the reference to 1648 * backing_object->backing_object moves from within 1649 * backing_object to within object. 1650 */ 1651 LIST_REMOVE(object, shadow_list); 1652 backing_object->shadow_count--; 1653 backing_object->generation++; 1654 if (backing_object->backing_object) { 1655 VM_OBJECT_LOCK(backing_object->backing_object); 1656 LIST_REMOVE(backing_object, shadow_list); 1657 LIST_INSERT_HEAD( 1658 &backing_object->backing_object->shadow_head, 1659 object, shadow_list); 1660 /* 1661 * The shadow_count has not changed. 1662 */ 1663 backing_object->backing_object->generation++; 1664 VM_OBJECT_UNLOCK(backing_object->backing_object); 1665 } 1666 object->backing_object = backing_object->backing_object; 1667 object->backing_object_offset += 1668 backing_object->backing_object_offset; 1669 1670 /* 1671 * Discard backing_object. 1672 * 1673 * Since the backing object has no pages, no pager left, 1674 * and no object references within it, all that is 1675 * necessary is to dispose of it. 1676 */ 1677 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1678 VM_OBJECT_UNLOCK(backing_object); 1679 1680 mtx_lock(&vm_object_list_mtx); 1681 TAILQ_REMOVE( 1682 &vm_object_list, 1683 backing_object, 1684 object_list 1685 ); 1686 mtx_unlock(&vm_object_list_mtx); 1687 1688 uma_zfree(obj_zone, backing_object); 1689 1690 object_collapses++; 1691 } else { 1692 vm_object_t new_backing_object; 1693 1694 /* 1695 * If we do not entirely shadow the backing object, 1696 * there is nothing we can do so we give up. 1697 */ 1698 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1699 VM_OBJECT_UNLOCK(backing_object); 1700 break; 1701 } 1702 1703 /* 1704 * Make the parent shadow the next object in the 1705 * chain. Deallocating backing_object will not remove 1706 * it, since its reference count is at least 2. 1707 */ 1708 LIST_REMOVE(object, shadow_list); 1709 backing_object->shadow_count--; 1710 backing_object->generation++; 1711 1712 new_backing_object = backing_object->backing_object; 1713 if ((object->backing_object = new_backing_object) != NULL) { 1714 VM_OBJECT_LOCK(new_backing_object); 1715 LIST_INSERT_HEAD( 1716 &new_backing_object->shadow_head, 1717 object, 1718 shadow_list 1719 ); 1720 new_backing_object->shadow_count++; 1721 new_backing_object->generation++; 1722 vm_object_reference_locked(new_backing_object); 1723 VM_OBJECT_UNLOCK(new_backing_object); 1724 object->backing_object_offset += 1725 backing_object->backing_object_offset; 1726 } 1727 1728 /* 1729 * Drop the reference count on backing_object. Since 1730 * its ref_count was at least 2, it will not vanish. 1731 */ 1732 backing_object->ref_count--; 1733 VM_OBJECT_UNLOCK(backing_object); 1734 object_bypasses++; 1735 } 1736 1737 /* 1738 * Try again with this object's new backing object. 1739 */ 1740 } 1741 } 1742 1743 /* 1744 * vm_object_page_remove: 1745 * 1746 * Removes all physical pages in the given range from the 1747 * object's list of pages. If the range's end is zero, all 1748 * physical pages from the range's start to the end of the object 1749 * are deleted. 1750 * 1751 * The object must be locked. 1752 */ 1753 void 1754 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1755 boolean_t clean_only) 1756 { 1757 vm_page_t p, next; 1758 1759 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1760 if (object->resident_page_count == 0) 1761 return; 1762 1763 /* 1764 * Since physically-backed objects do not use managed pages, we can't 1765 * remove pages from the object (we must instead remove the page 1766 * references, and then destroy the object). 1767 */ 1768 KASSERT(object->type != OBJT_PHYS, 1769 ("attempt to remove pages from a physical object")); 1770 1771 vm_object_pip_add(object, 1); 1772 again: 1773 vm_page_lock_queues(); 1774 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1775 if (p->pindex < start) { 1776 p = vm_page_splay(start, object->root); 1777 if ((object->root = p)->pindex < start) 1778 p = TAILQ_NEXT(p, listq); 1779 } 1780 } 1781 /* 1782 * Assert: the variable p is either (1) the page with the 1783 * least pindex greater than or equal to the parameter pindex 1784 * or (2) NULL. 1785 */ 1786 for (; 1787 p != NULL && (p->pindex < end || end == 0); 1788 p = next) { 1789 next = TAILQ_NEXT(p, listq); 1790 1791 if (p->wire_count != 0) { 1792 pmap_remove_all(p); 1793 if (!clean_only) 1794 p->valid = 0; 1795 continue; 1796 } 1797 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1798 goto again; 1799 if (clean_only && p->valid) { 1800 vm_page_test_dirty(p); 1801 if (p->valid & p->dirty) 1802 continue; 1803 } 1804 vm_page_busy(p); 1805 pmap_remove_all(p); 1806 vm_page_free(p); 1807 } 1808 vm_page_unlock_queues(); 1809 vm_object_pip_wakeup(object); 1810 } 1811 1812 /* 1813 * Routine: vm_object_coalesce 1814 * Function: Coalesces two objects backing up adjoining 1815 * regions of memory into a single object. 1816 * 1817 * returns TRUE if objects were combined. 1818 * 1819 * NOTE: Only works at the moment if the second object is NULL - 1820 * if it's not, which object do we lock first? 1821 * 1822 * Parameters: 1823 * prev_object First object to coalesce 1824 * prev_offset Offset into prev_object 1825 * next_object Second object into coalesce 1826 * next_offset Offset into next_object 1827 * 1828 * prev_size Size of reference to prev_object 1829 * next_size Size of reference to next_object 1830 * 1831 * Conditions: 1832 * The object must *not* be locked. 1833 */ 1834 boolean_t 1835 vm_object_coalesce(vm_object_t prev_object, vm_pindex_t prev_pindex, 1836 vm_size_t prev_size, vm_size_t next_size) 1837 { 1838 vm_pindex_t next_pindex; 1839 1840 if (prev_object == NULL) 1841 return (TRUE); 1842 VM_OBJECT_LOCK(prev_object); 1843 if (prev_object->type != OBJT_DEFAULT && 1844 prev_object->type != OBJT_SWAP) { 1845 VM_OBJECT_UNLOCK(prev_object); 1846 return (FALSE); 1847 } 1848 1849 /* 1850 * Try to collapse the object first 1851 */ 1852 vm_object_collapse(prev_object); 1853 1854 /* 1855 * Can't coalesce if: . more than one reference . paged out . shadows 1856 * another object . has a copy elsewhere (any of which mean that the 1857 * pages not mapped to prev_entry may be in use anyway) 1858 */ 1859 if (prev_object->backing_object != NULL) { 1860 VM_OBJECT_UNLOCK(prev_object); 1861 return (FALSE); 1862 } 1863 1864 prev_size >>= PAGE_SHIFT; 1865 next_size >>= PAGE_SHIFT; 1866 next_pindex = prev_pindex + prev_size; 1867 1868 if ((prev_object->ref_count > 1) && 1869 (prev_object->size != next_pindex)) { 1870 VM_OBJECT_UNLOCK(prev_object); 1871 return (FALSE); 1872 } 1873 1874 /* 1875 * Remove any pages that may still be in the object from a previous 1876 * deallocation. 1877 */ 1878 if (next_pindex < prev_object->size) { 1879 vm_object_page_remove(prev_object, 1880 next_pindex, 1881 next_pindex + next_size, FALSE); 1882 if (prev_object->type == OBJT_SWAP) 1883 swap_pager_freespace(prev_object, 1884 next_pindex, next_size); 1885 } 1886 1887 /* 1888 * Extend the object if necessary. 1889 */ 1890 if (next_pindex + next_size > prev_object->size) 1891 prev_object->size = next_pindex + next_size; 1892 1893 VM_OBJECT_UNLOCK(prev_object); 1894 return (TRUE); 1895 } 1896 1897 void 1898 vm_object_set_writeable_dirty(vm_object_t object) 1899 { 1900 struct vnode *vp; 1901 1902 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1903 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1904 if (object->type == OBJT_VNODE && 1905 (vp = (struct vnode *)object->handle) != NULL) { 1906 VI_LOCK(vp); 1907 if ((vp->v_iflag & VI_OBJDIRTY) == 0) 1908 vp->v_iflag |= VI_OBJDIRTY; 1909 VI_UNLOCK(vp); 1910 } 1911 } 1912 1913 #include "opt_ddb.h" 1914 #ifdef DDB 1915 #include <sys/kernel.h> 1916 1917 #include <sys/cons.h> 1918 1919 #include <ddb/ddb.h> 1920 1921 static int 1922 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry) 1923 { 1924 vm_map_t tmpm; 1925 vm_map_entry_t tmpe; 1926 vm_object_t obj; 1927 int entcount; 1928 1929 if (map == 0) 1930 return 0; 1931 1932 if (entry == 0) { 1933 tmpe = map->header.next; 1934 entcount = map->nentries; 1935 while (entcount-- && (tmpe != &map->header)) { 1936 if (_vm_object_in_map(map, object, tmpe)) { 1937 return 1; 1938 } 1939 tmpe = tmpe->next; 1940 } 1941 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) { 1942 tmpm = entry->object.sub_map; 1943 tmpe = tmpm->header.next; 1944 entcount = tmpm->nentries; 1945 while (entcount-- && tmpe != &tmpm->header) { 1946 if (_vm_object_in_map(tmpm, object, tmpe)) { 1947 return 1; 1948 } 1949 tmpe = tmpe->next; 1950 } 1951 } else if ((obj = entry->object.vm_object) != NULL) { 1952 for (; obj; obj = obj->backing_object) 1953 if (obj == object) { 1954 return 1; 1955 } 1956 } 1957 return 0; 1958 } 1959 1960 static int 1961 vm_object_in_map(vm_object_t object) 1962 { 1963 struct proc *p; 1964 1965 /* sx_slock(&allproc_lock); */ 1966 LIST_FOREACH(p, &allproc, p_list) { 1967 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */) 1968 continue; 1969 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) { 1970 /* sx_sunlock(&allproc_lock); */ 1971 return 1; 1972 } 1973 } 1974 /* sx_sunlock(&allproc_lock); */ 1975 if (_vm_object_in_map(kernel_map, object, 0)) 1976 return 1; 1977 if (_vm_object_in_map(kmem_map, object, 0)) 1978 return 1; 1979 if (_vm_object_in_map(pager_map, object, 0)) 1980 return 1; 1981 if (_vm_object_in_map(buffer_map, object, 0)) 1982 return 1; 1983 return 0; 1984 } 1985 1986 DB_SHOW_COMMAND(vmochk, vm_object_check) 1987 { 1988 vm_object_t object; 1989 1990 /* 1991 * make sure that internal objs are in a map somewhere 1992 * and none have zero ref counts. 1993 */ 1994 TAILQ_FOREACH(object, &vm_object_list, object_list) { 1995 if (object->handle == NULL && 1996 (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) { 1997 if (object->ref_count == 0) { 1998 db_printf("vmochk: internal obj has zero ref count: %ld\n", 1999 (long)object->size); 2000 } 2001 if (!vm_object_in_map(object)) { 2002 db_printf( 2003 "vmochk: internal obj is not in a map: " 2004 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n", 2005 object->ref_count, (u_long)object->size, 2006 (u_long)object->size, 2007 (void *)object->backing_object); 2008 } 2009 } 2010 } 2011 } 2012 2013 /* 2014 * vm_object_print: [ debug ] 2015 */ 2016 DB_SHOW_COMMAND(object, vm_object_print_static) 2017 { 2018 /* XXX convert args. */ 2019 vm_object_t object = (vm_object_t)addr; 2020 boolean_t full = have_addr; 2021 2022 vm_page_t p; 2023 2024 /* XXX count is an (unused) arg. Avoid shadowing it. */ 2025 #define count was_count 2026 2027 int count; 2028 2029 if (object == NULL) 2030 return; 2031 2032 db_iprintf( 2033 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x\n", 2034 object, (int)object->type, (uintmax_t)object->size, 2035 object->resident_page_count, object->ref_count, object->flags); 2036 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n", 2037 object->shadow_count, 2038 object->backing_object ? object->backing_object->ref_count : 0, 2039 object->backing_object, (uintmax_t)object->backing_object_offset); 2040 2041 if (!full) 2042 return; 2043 2044 db_indent += 2; 2045 count = 0; 2046 TAILQ_FOREACH(p, &object->memq, listq) { 2047 if (count == 0) 2048 db_iprintf("memory:="); 2049 else if (count == 6) { 2050 db_printf("\n"); 2051 db_iprintf(" ..."); 2052 count = 0; 2053 } else 2054 db_printf(","); 2055 count++; 2056 2057 db_printf("(off=0x%jx,page=0x%jx)", 2058 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p)); 2059 } 2060 if (count != 0) 2061 db_printf("\n"); 2062 db_indent -= 2; 2063 } 2064 2065 /* XXX. */ 2066 #undef count 2067 2068 /* XXX need this non-static entry for calling from vm_map_print. */ 2069 void 2070 vm_object_print( 2071 /* db_expr_t */ long addr, 2072 boolean_t have_addr, 2073 /* db_expr_t */ long count, 2074 char *modif) 2075 { 2076 vm_object_print_static(addr, have_addr, count, modif); 2077 } 2078 2079 DB_SHOW_COMMAND(vmopag, vm_object_print_pages) 2080 { 2081 vm_object_t object; 2082 int nl = 0; 2083 int c; 2084 2085 TAILQ_FOREACH(object, &vm_object_list, object_list) { 2086 vm_pindex_t idx, fidx; 2087 vm_pindex_t osize; 2088 vm_paddr_t pa = -1, padiff; 2089 int rcount; 2090 vm_page_t m; 2091 2092 db_printf("new object: %p\n", (void *)object); 2093 if (nl > 18) { 2094 c = cngetc(); 2095 if (c != ' ') 2096 return; 2097 nl = 0; 2098 } 2099 nl++; 2100 rcount = 0; 2101 fidx = 0; 2102 osize = object->size; 2103 if (osize > 128) 2104 osize = 128; 2105 for (idx = 0; idx < osize; idx++) { 2106 m = vm_page_lookup(object, idx); 2107 if (m == NULL) { 2108 if (rcount) { 2109 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2110 (long)fidx, rcount, (long)pa); 2111 if (nl > 18) { 2112 c = cngetc(); 2113 if (c != ' ') 2114 return; 2115 nl = 0; 2116 } 2117 nl++; 2118 rcount = 0; 2119 } 2120 continue; 2121 } 2122 2123 2124 if (rcount && 2125 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) { 2126 ++rcount; 2127 continue; 2128 } 2129 if (rcount) { 2130 padiff = pa + rcount * PAGE_SIZE - VM_PAGE_TO_PHYS(m); 2131 padiff >>= PAGE_SHIFT; 2132 padiff &= PQ_L2_MASK; 2133 if (padiff == 0) { 2134 pa = VM_PAGE_TO_PHYS(m) - rcount * PAGE_SIZE; 2135 ++rcount; 2136 continue; 2137 } 2138 db_printf(" index(%ld)run(%d)pa(0x%lx)", 2139 (long)fidx, rcount, (long)pa); 2140 db_printf("pd(%ld)\n", (long)padiff); 2141 if (nl > 18) { 2142 c = cngetc(); 2143 if (c != ' ') 2144 return; 2145 nl = 0; 2146 } 2147 nl++; 2148 } 2149 fidx = idx; 2150 pa = VM_PAGE_TO_PHYS(m); 2151 rcount = 1; 2152 } 2153 if (rcount) { 2154 db_printf(" index(%ld)run(%d)pa(0x%lx)\n", 2155 (long)fidx, rcount, (long)pa); 2156 if (nl > 18) { 2157 c = cngetc(); 2158 if (c != ' ') 2159 return; 2160 nl = 0; 2161 } 2162 nl++; 2163 } 2164 } 2165 } 2166 #endif /* DDB */ 2167