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