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 /* 254 * The lock portion of struct vm_object must be type stable due 255 * to vm_pageout_fallback_object_lock locking a vm object 256 * without holding any references to it. 257 */ 258 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL, 259 #ifdef INVARIANTS 260 vm_object_zdtor, 261 #else 262 NULL, 263 #endif 264 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_VM|UMA_ZONE_NOFREE); 265 uma_prealloc(obj_zone, VM_OBJECTS_INIT); 266 } 267 268 void 269 vm_object_clear_flag(vm_object_t object, u_short bits) 270 { 271 272 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 273 object->flags &= ~bits; 274 } 275 276 void 277 vm_object_pip_add(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_subtract(vm_object_t object, short i) 286 { 287 288 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 289 object->paging_in_progress -= i; 290 } 291 292 void 293 vm_object_pip_wakeup(vm_object_t object) 294 { 295 296 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 297 object->paging_in_progress--; 298 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 299 vm_object_clear_flag(object, OBJ_PIPWNT); 300 wakeup(object); 301 } 302 } 303 304 void 305 vm_object_pip_wakeupn(vm_object_t object, short i) 306 { 307 308 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 309 if (i) 310 object->paging_in_progress -= i; 311 if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) { 312 vm_object_clear_flag(object, OBJ_PIPWNT); 313 wakeup(object); 314 } 315 } 316 317 void 318 vm_object_pip_wait(vm_object_t object, char *waitid) 319 { 320 321 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 322 while (object->paging_in_progress) { 323 object->flags |= OBJ_PIPWNT; 324 msleep(object, VM_OBJECT_MTX(object), PVM, waitid, 0); 325 } 326 } 327 328 /* 329 * vm_object_allocate: 330 * 331 * Returns a new object with the given size. 332 */ 333 vm_object_t 334 vm_object_allocate(objtype_t type, vm_pindex_t size) 335 { 336 vm_object_t object; 337 338 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK); 339 _vm_object_allocate(type, size, object); 340 return (object); 341 } 342 343 344 /* 345 * vm_object_reference: 346 * 347 * Gets another reference to the given object. Note: OBJ_DEAD 348 * objects can be referenced during final cleaning. 349 */ 350 void 351 vm_object_reference(vm_object_t object) 352 { 353 struct vnode *vp; 354 int flags; 355 356 if (object == NULL) 357 return; 358 VM_OBJECT_LOCK(object); 359 object->ref_count++; 360 if (object->type == OBJT_VNODE) { 361 vp = object->handle; 362 VI_LOCK(vp); 363 VM_OBJECT_UNLOCK(object); 364 for (flags = LK_INTERLOCK; vget(vp, flags, curthread); 365 flags = 0) 366 printf("vm_object_reference: delay in vget\n"); 367 } else 368 VM_OBJECT_UNLOCK(object); 369 } 370 371 /* 372 * vm_object_reference_locked: 373 * 374 * Gets another reference to the given object. 375 * 376 * The object must be locked. 377 */ 378 void 379 vm_object_reference_locked(vm_object_t object) 380 { 381 struct vnode *vp; 382 383 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 384 KASSERT((object->flags & OBJ_DEAD) == 0, 385 ("vm_object_reference_locked: dead object referenced")); 386 object->ref_count++; 387 if (object->type == OBJT_VNODE) { 388 vp = object->handle; 389 vref(vp); 390 } 391 } 392 393 /* 394 * Handle deallocating an object of type OBJT_VNODE. 395 */ 396 void 397 vm_object_vndeallocate(vm_object_t object) 398 { 399 struct vnode *vp = (struct vnode *) object->handle; 400 401 VFS_ASSERT_GIANT(vp->v_mount); 402 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 403 KASSERT(object->type == OBJT_VNODE, 404 ("vm_object_vndeallocate: not a vnode object")); 405 KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp")); 406 #ifdef INVARIANTS 407 if (object->ref_count == 0) { 408 vprint("vm_object_vndeallocate", vp); 409 panic("vm_object_vndeallocate: bad object reference count"); 410 } 411 #endif 412 413 object->ref_count--; 414 if (object->ref_count == 0) { 415 mp_fixme("Unlocked vflag access."); 416 vp->v_vflag &= ~VV_TEXT; 417 } 418 VM_OBJECT_UNLOCK(object); 419 /* 420 * vrele may need a vop lock 421 */ 422 vrele(vp); 423 } 424 425 /* 426 * vm_object_deallocate: 427 * 428 * Release a reference to the specified object, 429 * gained either through a vm_object_allocate 430 * or a vm_object_reference call. When all references 431 * are gone, storage associated with this object 432 * may be relinquished. 433 * 434 * No object may be locked. 435 */ 436 void 437 vm_object_deallocate(vm_object_t object) 438 { 439 vm_object_t temp; 440 441 while (object != NULL) { 442 int vfslocked; 443 /* 444 * In general, the object should be locked when working with 445 * its type. In this case, in order to maintain proper lock 446 * ordering, an exception is possible because a vnode-backed 447 * object never changes its type. 448 */ 449 vfslocked = 0; 450 if (object->type == OBJT_VNODE) { 451 struct vnode *vp = (struct vnode *) object->handle; 452 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 453 } 454 VM_OBJECT_LOCK(object); 455 if (object->type == OBJT_VNODE) { 456 vm_object_vndeallocate(object); 457 VFS_UNLOCK_GIANT(vfslocked); 458 return; 459 } 460 461 KASSERT(object->ref_count != 0, 462 ("vm_object_deallocate: object deallocated too many times: %d", object->type)); 463 464 /* 465 * If the reference count goes to 0 we start calling 466 * vm_object_terminate() on the object chain. 467 * A ref count of 1 may be a special case depending on the 468 * shadow count being 0 or 1. 469 */ 470 object->ref_count--; 471 if (object->ref_count > 1) { 472 VM_OBJECT_UNLOCK(object); 473 return; 474 } else if (object->ref_count == 1) { 475 if (object->shadow_count == 0) { 476 vm_object_set_flag(object, OBJ_ONEMAPPING); 477 } else if ((object->shadow_count == 1) && 478 (object->handle == NULL) && 479 (object->type == OBJT_DEFAULT || 480 object->type == OBJT_SWAP)) { 481 vm_object_t robject; 482 483 robject = LIST_FIRST(&object->shadow_head); 484 KASSERT(robject != NULL, 485 ("vm_object_deallocate: ref_count: %d, shadow_count: %d", 486 object->ref_count, 487 object->shadow_count)); 488 if (!VM_OBJECT_TRYLOCK(robject)) { 489 /* 490 * Avoid a potential deadlock. 491 */ 492 object->ref_count++; 493 VM_OBJECT_UNLOCK(object); 494 /* 495 * More likely than not the thread 496 * holding robject's lock has lower 497 * priority than the current thread. 498 * Let the lower priority thread run. 499 */ 500 tsleep(&proc0, PVM, "vmo_de", 1); 501 continue; 502 } 503 /* 504 * Collapse object into its shadow unless its 505 * shadow is dead. In that case, object will 506 * be deallocated by the thread that is 507 * deallocating its shadow. 508 */ 509 if ((robject->flags & OBJ_DEAD) == 0 && 510 (robject->handle == NULL) && 511 (robject->type == OBJT_DEFAULT || 512 robject->type == OBJT_SWAP)) { 513 514 robject->ref_count++; 515 retry: 516 if (robject->paging_in_progress) { 517 VM_OBJECT_UNLOCK(object); 518 vm_object_pip_wait(robject, 519 "objde1"); 520 VM_OBJECT_LOCK(object); 521 goto retry; 522 } else if (object->paging_in_progress) { 523 VM_OBJECT_UNLOCK(robject); 524 object->flags |= OBJ_PIPWNT; 525 msleep(object, 526 VM_OBJECT_MTX(object), 527 PDROP | PVM, "objde2", 0); 528 VM_OBJECT_LOCK(robject); 529 VM_OBJECT_LOCK(object); 530 goto retry; 531 } 532 VM_OBJECT_UNLOCK(object); 533 if (robject->ref_count == 1) { 534 robject->ref_count--; 535 object = robject; 536 goto doterm; 537 } 538 object = robject; 539 vm_object_collapse(object); 540 VM_OBJECT_UNLOCK(object); 541 continue; 542 } 543 VM_OBJECT_UNLOCK(robject); 544 } 545 VM_OBJECT_UNLOCK(object); 546 return; 547 } 548 doterm: 549 temp = object->backing_object; 550 if (temp != NULL) { 551 VM_OBJECT_LOCK(temp); 552 LIST_REMOVE(object, shadow_list); 553 temp->shadow_count--; 554 temp->generation++; 555 VM_OBJECT_UNLOCK(temp); 556 object->backing_object = NULL; 557 } 558 /* 559 * Don't double-terminate, we could be in a termination 560 * recursion due to the terminate having to sync data 561 * to disk. 562 */ 563 if ((object->flags & OBJ_DEAD) == 0) 564 vm_object_terminate(object); 565 else 566 VM_OBJECT_UNLOCK(object); 567 object = temp; 568 } 569 } 570 571 /* 572 * vm_object_terminate actually destroys the specified object, freeing 573 * up all previously used resources. 574 * 575 * The object must be locked. 576 * This routine may block. 577 */ 578 void 579 vm_object_terminate(vm_object_t object) 580 { 581 vm_page_t p; 582 583 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 584 585 /* 586 * Make sure no one uses us. 587 */ 588 vm_object_set_flag(object, OBJ_DEAD); 589 590 /* 591 * wait for the pageout daemon to be done with the object 592 */ 593 vm_object_pip_wait(object, "objtrm"); 594 595 KASSERT(!object->paging_in_progress, 596 ("vm_object_terminate: pageout in progress")); 597 598 /* 599 * Clean and free the pages, as appropriate. All references to the 600 * object are gone, so we don't need to lock it. 601 */ 602 if (object->type == OBJT_VNODE) { 603 struct vnode *vp = (struct vnode *)object->handle; 604 605 /* 606 * Clean pages and flush buffers. 607 */ 608 vm_object_page_clean(object, 0, 0, OBJPC_SYNC); 609 VM_OBJECT_UNLOCK(object); 610 611 vinvalbuf(vp, V_SAVE, NULL, 0, 0); 612 613 VM_OBJECT_LOCK(object); 614 } 615 616 KASSERT(object->ref_count == 0, 617 ("vm_object_terminate: object with references, ref_count=%d", 618 object->ref_count)); 619 620 /* 621 * Now free any remaining pages. For internal objects, this also 622 * removes them from paging queues. Don't free wired pages, just 623 * remove them from the object. 624 */ 625 vm_page_lock_queues(); 626 while ((p = TAILQ_FIRST(&object->memq)) != NULL) { 627 KASSERT(!p->busy && (p->flags & PG_BUSY) == 0, 628 ("vm_object_terminate: freeing busy page %p " 629 "p->busy = %d, p->flags %x\n", p, p->busy, p->flags)); 630 if (p->wire_count == 0) { 631 vm_page_free(p); 632 cnt.v_pfree++; 633 } else { 634 vm_page_remove(p); 635 } 636 } 637 vm_page_unlock_queues(); 638 639 /* 640 * Let the pager know object is dead. 641 */ 642 vm_pager_deallocate(object); 643 VM_OBJECT_UNLOCK(object); 644 645 /* 646 * Remove the object from the global object list. 647 */ 648 mtx_lock(&vm_object_list_mtx); 649 TAILQ_REMOVE(&vm_object_list, object, object_list); 650 mtx_unlock(&vm_object_list_mtx); 651 652 /* 653 * Free the space for the object. 654 */ 655 uma_zfree(obj_zone, object); 656 } 657 658 /* 659 * vm_object_page_clean 660 * 661 * Clean all dirty pages in the specified range of object. Leaves page 662 * on whatever queue it is currently on. If NOSYNC is set then do not 663 * write out pages with PG_NOSYNC set (originally comes from MAP_NOSYNC), 664 * leaving the object dirty. 665 * 666 * When stuffing pages asynchronously, allow clustering. XXX we need a 667 * synchronous clustering mode implementation. 668 * 669 * Odd semantics: if start == end, we clean everything. 670 * 671 * The object must be locked. 672 */ 673 void 674 vm_object_page_clean(vm_object_t object, vm_pindex_t start, vm_pindex_t end, int flags) 675 { 676 vm_page_t p, np; 677 vm_pindex_t tstart, tend; 678 vm_pindex_t pi; 679 int clearobjflags; 680 int pagerflags; 681 int curgeneration; 682 683 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 684 if (object->type != OBJT_VNODE || 685 (object->flags & OBJ_MIGHTBEDIRTY) == 0) 686 return; 687 688 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) ? VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK; 689 pagerflags |= (flags & OBJPC_INVAL) ? VM_PAGER_PUT_INVAL : 0; 690 691 vm_object_set_flag(object, OBJ_CLEANING); 692 693 tstart = start; 694 if (end == 0) { 695 tend = object->size; 696 } else { 697 tend = end; 698 } 699 700 vm_page_lock_queues(); 701 /* 702 * If the caller is smart and only msync()s a range he knows is 703 * dirty, we may be able to avoid an object scan. This results in 704 * a phenominal improvement in performance. We cannot do this 705 * as a matter of course because the object may be huge - e.g. 706 * the size might be in the gigabytes or terrabytes. 707 */ 708 if (msync_flush_flags & MSYNC_FLUSH_HARDSEQ) { 709 vm_pindex_t tscan; 710 int scanlimit; 711 int scanreset; 712 713 scanreset = object->resident_page_count / EASY_SCAN_FACTOR; 714 if (scanreset < 16) 715 scanreset = 16; 716 pagerflags |= VM_PAGER_IGNORE_CLEANCHK; 717 718 scanlimit = scanreset; 719 tscan = tstart; 720 while (tscan < tend) { 721 curgeneration = object->generation; 722 p = vm_page_lookup(object, tscan); 723 if (p == NULL || p->valid == 0 || 724 (p->queue - p->pc) == PQ_CACHE) { 725 if (--scanlimit == 0) 726 break; 727 ++tscan; 728 continue; 729 } 730 vm_page_test_dirty(p); 731 if ((p->dirty & p->valid) == 0) { 732 if (--scanlimit == 0) 733 break; 734 ++tscan; 735 continue; 736 } 737 /* 738 * If we have been asked to skip nosync pages and 739 * this is a nosync page, we can't continue. 740 */ 741 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 742 if (--scanlimit == 0) 743 break; 744 ++tscan; 745 continue; 746 } 747 scanlimit = scanreset; 748 749 /* 750 * This returns 0 if it was unable to busy the first 751 * page (i.e. had to sleep). 752 */ 753 tscan += vm_object_page_collect_flush(object, p, curgeneration, pagerflags); 754 } 755 756 /* 757 * If everything was dirty and we flushed it successfully, 758 * and the requested range is not the entire object, we 759 * don't have to mess with CLEANCHK or MIGHTBEDIRTY and can 760 * return immediately. 761 */ 762 if (tscan >= tend && (tstart || tend < object->size)) { 763 vm_page_unlock_queues(); 764 vm_object_clear_flag(object, OBJ_CLEANING); 765 return; 766 } 767 pagerflags &= ~VM_PAGER_IGNORE_CLEANCHK; 768 } 769 770 /* 771 * Generally set CLEANCHK interlock and make the page read-only so 772 * we can then clear the object flags. 773 * 774 * However, if this is a nosync mmap then the object is likely to 775 * stay dirty so do not mess with the page and do not clear the 776 * object flags. 777 */ 778 clearobjflags = 1; 779 TAILQ_FOREACH(p, &object->memq, listq) { 780 vm_page_flag_set(p, PG_CLEANCHK); 781 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) 782 clearobjflags = 0; 783 else 784 pmap_page_protect(p, VM_PROT_READ); 785 } 786 787 if (clearobjflags && (tstart == 0) && (tend == object->size)) { 788 struct vnode *vp; 789 790 vm_object_clear_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 791 if (object->type == OBJT_VNODE && 792 (vp = (struct vnode *)object->handle) != NULL) { 793 VI_LOCK(vp); 794 if (vp->v_iflag & VI_OBJDIRTY) 795 vp->v_iflag &= ~VI_OBJDIRTY; 796 VI_UNLOCK(vp); 797 } 798 } 799 800 rescan: 801 curgeneration = object->generation; 802 803 for (p = TAILQ_FIRST(&object->memq); p; p = np) { 804 int n; 805 806 np = TAILQ_NEXT(p, listq); 807 808 again: 809 pi = p->pindex; 810 if (((p->flags & PG_CLEANCHK) == 0) || 811 (pi < tstart) || (pi >= tend) || 812 (p->valid == 0) || 813 ((p->queue - p->pc) == PQ_CACHE)) { 814 vm_page_flag_clear(p, PG_CLEANCHK); 815 continue; 816 } 817 818 vm_page_test_dirty(p); 819 if ((p->dirty & p->valid) == 0) { 820 vm_page_flag_clear(p, PG_CLEANCHK); 821 continue; 822 } 823 824 /* 825 * If we have been asked to skip nosync pages and this is a 826 * nosync page, skip it. Note that the object flags were 827 * not cleared in this case so we do not have to set them. 828 */ 829 if ((flags & OBJPC_NOSYNC) && (p->flags & PG_NOSYNC)) { 830 vm_page_flag_clear(p, PG_CLEANCHK); 831 continue; 832 } 833 834 n = vm_object_page_collect_flush(object, p, 835 curgeneration, pagerflags); 836 if (n == 0) 837 goto rescan; 838 839 if (object->generation != curgeneration) 840 goto rescan; 841 842 /* 843 * Try to optimize the next page. If we can't we pick up 844 * our (random) scan where we left off. 845 */ 846 if (msync_flush_flags & MSYNC_FLUSH_SOFTSEQ) { 847 if ((p = vm_page_lookup(object, pi + n)) != NULL) 848 goto again; 849 } 850 } 851 vm_page_unlock_queues(); 852 #if 0 853 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC)?MNT_WAIT:0, curproc); 854 #endif 855 856 vm_object_clear_flag(object, OBJ_CLEANING); 857 return; 858 } 859 860 static int 861 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int curgeneration, int pagerflags) 862 { 863 int runlen; 864 int maxf; 865 int chkb; 866 int maxb; 867 int i; 868 vm_pindex_t pi; 869 vm_page_t maf[vm_pageout_page_count]; 870 vm_page_t mab[vm_pageout_page_count]; 871 vm_page_t ma[vm_pageout_page_count]; 872 873 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 return(0); 879 } 880 } 881 maxf = 0; 882 for(i = 1; i < vm_pageout_page_count; i++) { 883 vm_page_t tp; 884 885 if ((tp = vm_page_lookup(object, pi + i)) != NULL) { 886 if ((tp->flags & PG_BUSY) || 887 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 888 (tp->flags & PG_CLEANCHK) == 0) || 889 (tp->busy != 0)) 890 break; 891 if((tp->queue - tp->pc) == PQ_CACHE) { 892 vm_page_flag_clear(tp, PG_CLEANCHK); 893 break; 894 } 895 vm_page_test_dirty(tp); 896 if ((tp->dirty & tp->valid) == 0) { 897 vm_page_flag_clear(tp, PG_CLEANCHK); 898 break; 899 } 900 maf[ i - 1 ] = tp; 901 maxf++; 902 continue; 903 } 904 break; 905 } 906 907 maxb = 0; 908 chkb = vm_pageout_page_count - maxf; 909 if (chkb) { 910 for(i = 1; i < chkb;i++) { 911 vm_page_t tp; 912 913 if ((tp = vm_page_lookup(object, pi - i)) != NULL) { 914 if ((tp->flags & PG_BUSY) || 915 ((pagerflags & VM_PAGER_IGNORE_CLEANCHK) == 0 && 916 (tp->flags & PG_CLEANCHK) == 0) || 917 (tp->busy != 0)) 918 break; 919 if ((tp->queue - tp->pc) == PQ_CACHE) { 920 vm_page_flag_clear(tp, PG_CLEANCHK); 921 break; 922 } 923 vm_page_test_dirty(tp); 924 if ((tp->dirty & tp->valid) == 0) { 925 vm_page_flag_clear(tp, PG_CLEANCHK); 926 break; 927 } 928 mab[ i - 1 ] = tp; 929 maxb++; 930 continue; 931 } 932 break; 933 } 934 } 935 936 for(i = 0; i < maxb; i++) { 937 int index = (maxb - i) - 1; 938 ma[index] = mab[i]; 939 vm_page_flag_clear(ma[index], PG_CLEANCHK); 940 } 941 vm_page_flag_clear(p, PG_CLEANCHK); 942 ma[maxb] = p; 943 for(i = 0; i < maxf; i++) { 944 int index = (maxb + i) + 1; 945 ma[index] = maf[i]; 946 vm_page_flag_clear(ma[index], PG_CLEANCHK); 947 } 948 runlen = maxb + maxf + 1; 949 950 vm_pageout_flush(ma, runlen, pagerflags); 951 for (i = 0; i < runlen; i++) { 952 if (ma[i]->valid & ma[i]->dirty) { 953 pmap_page_protect(ma[i], VM_PROT_READ); 954 vm_page_flag_set(ma[i], PG_CLEANCHK); 955 956 /* 957 * maxf will end up being the actual number of pages 958 * we wrote out contiguously, non-inclusive of the 959 * first page. We do not count look-behind pages. 960 */ 961 if (i >= maxb + 1 && (maxf > i - maxb - 1)) 962 maxf = i - maxb - 1; 963 } 964 } 965 return(maxf + 1); 966 } 967 968 /* 969 * Note that there is absolutely no sense in writing out 970 * anonymous objects, so we track down the vnode object 971 * to write out. 972 * We invalidate (remove) all pages from the address space 973 * for semantic correctness. 974 * 975 * Note: certain anonymous maps, such as MAP_NOSYNC maps, 976 * may start out with a NULL object. 977 */ 978 void 979 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size, 980 boolean_t syncio, boolean_t invalidate) 981 { 982 vm_object_t backing_object; 983 struct vnode *vp; 984 int flags; 985 986 if (object == NULL) 987 return; 988 VM_OBJECT_LOCK(object); 989 while ((backing_object = object->backing_object) != NULL) { 990 VM_OBJECT_LOCK(backing_object); 991 offset += object->backing_object_offset; 992 VM_OBJECT_UNLOCK(object); 993 object = backing_object; 994 if (object->size < OFF_TO_IDX(offset + size)) 995 size = IDX_TO_OFF(object->size) - offset; 996 } 997 /* 998 * Flush pages if writing is allowed, invalidate them 999 * if invalidation requested. Pages undergoing I/O 1000 * will be ignored by vm_object_page_remove(). 1001 * 1002 * We cannot lock the vnode and then wait for paging 1003 * to complete without deadlocking against vm_fault. 1004 * Instead we simply call vm_object_page_remove() and 1005 * allow it to block internally on a page-by-page 1006 * basis when it encounters pages undergoing async 1007 * I/O. 1008 */ 1009 if (object->type == OBJT_VNODE && 1010 (object->flags & OBJ_MIGHTBEDIRTY) != 0) { 1011 int vfslocked; 1012 vp = object->handle; 1013 VM_OBJECT_UNLOCK(object); 1014 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 1015 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); 1016 flags = (syncio || invalidate) ? OBJPC_SYNC : 0; 1017 flags |= invalidate ? OBJPC_INVAL : 0; 1018 VM_OBJECT_LOCK(object); 1019 vm_object_page_clean(object, 1020 OFF_TO_IDX(offset), 1021 OFF_TO_IDX(offset + size + PAGE_MASK), 1022 flags); 1023 VM_OBJECT_UNLOCK(object); 1024 VOP_UNLOCK(vp, 0, curthread); 1025 VFS_UNLOCK_GIANT(vfslocked); 1026 VM_OBJECT_LOCK(object); 1027 } 1028 if ((object->type == OBJT_VNODE || 1029 object->type == OBJT_DEVICE) && invalidate) { 1030 boolean_t purge; 1031 purge = old_msync || (object->type == OBJT_DEVICE); 1032 vm_object_page_remove(object, 1033 OFF_TO_IDX(offset), 1034 OFF_TO_IDX(offset + size + PAGE_MASK), 1035 purge ? FALSE : TRUE); 1036 } 1037 VM_OBJECT_UNLOCK(object); 1038 } 1039 1040 /* 1041 * vm_object_madvise: 1042 * 1043 * Implements the madvise function at the object/page level. 1044 * 1045 * MADV_WILLNEED (any object) 1046 * 1047 * Activate the specified pages if they are resident. 1048 * 1049 * MADV_DONTNEED (any object) 1050 * 1051 * Deactivate the specified pages if they are resident. 1052 * 1053 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects, 1054 * OBJ_ONEMAPPING only) 1055 * 1056 * Deactivate and clean the specified pages if they are 1057 * resident. This permits the process to reuse the pages 1058 * without faulting or the kernel to reclaim the pages 1059 * without I/O. 1060 */ 1061 void 1062 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, int count, int advise) 1063 { 1064 vm_pindex_t end, tpindex; 1065 vm_object_t backing_object, tobject; 1066 vm_page_t m; 1067 1068 if (object == NULL) 1069 return; 1070 VM_OBJECT_LOCK(object); 1071 end = pindex + count; 1072 /* 1073 * Locate and adjust resident pages 1074 */ 1075 for (; pindex < end; pindex += 1) { 1076 relookup: 1077 tobject = object; 1078 tpindex = pindex; 1079 shadowlookup: 1080 /* 1081 * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages 1082 * and those pages must be OBJ_ONEMAPPING. 1083 */ 1084 if (advise == MADV_FREE) { 1085 if ((tobject->type != OBJT_DEFAULT && 1086 tobject->type != OBJT_SWAP) || 1087 (tobject->flags & OBJ_ONEMAPPING) == 0) { 1088 goto unlock_tobject; 1089 } 1090 } 1091 m = vm_page_lookup(tobject, tpindex); 1092 if (m == NULL) { 1093 /* 1094 * There may be swap even if there is no backing page 1095 */ 1096 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1097 swap_pager_freespace(tobject, tpindex, 1); 1098 /* 1099 * next object 1100 */ 1101 backing_object = tobject->backing_object; 1102 if (backing_object == NULL) 1103 goto unlock_tobject; 1104 VM_OBJECT_LOCK(backing_object); 1105 tpindex += OFF_TO_IDX(tobject->backing_object_offset); 1106 if (tobject != object) 1107 VM_OBJECT_UNLOCK(tobject); 1108 tobject = backing_object; 1109 goto shadowlookup; 1110 } 1111 /* 1112 * If the page is busy or not in a normal active state, 1113 * we skip it. If the page is not managed there are no 1114 * page queues to mess with. Things can break if we mess 1115 * with pages in any of the below states. 1116 */ 1117 vm_page_lock_queues(); 1118 if (m->hold_count || 1119 m->wire_count || 1120 (m->flags & PG_UNMANAGED) || 1121 m->valid != VM_PAGE_BITS_ALL) { 1122 vm_page_unlock_queues(); 1123 goto unlock_tobject; 1124 } 1125 if ((m->flags & PG_BUSY) || m->busy) { 1126 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1127 if (object != tobject) 1128 VM_OBJECT_UNLOCK(object); 1129 VM_OBJECT_UNLOCK(tobject); 1130 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "madvpo", 0); 1131 VM_OBJECT_LOCK(object); 1132 goto relookup; 1133 } 1134 if (advise == MADV_WILLNEED) { 1135 vm_page_activate(m); 1136 } else if (advise == MADV_DONTNEED) { 1137 vm_page_dontneed(m); 1138 } else if (advise == MADV_FREE) { 1139 /* 1140 * Mark the page clean. This will allow the page 1141 * to be freed up by the system. However, such pages 1142 * are often reused quickly by malloc()/free() 1143 * so we do not do anything that would cause 1144 * a page fault if we can help it. 1145 * 1146 * Specifically, we do not try to actually free 1147 * the page now nor do we try to put it in the 1148 * cache (which would cause a page fault on reuse). 1149 * 1150 * But we do make the page is freeable as we 1151 * can without actually taking the step of unmapping 1152 * it. 1153 */ 1154 pmap_clear_modify(m); 1155 m->dirty = 0; 1156 m->act_count = 0; 1157 vm_page_dontneed(m); 1158 } 1159 vm_page_unlock_queues(); 1160 if (advise == MADV_FREE && tobject->type == OBJT_SWAP) 1161 swap_pager_freespace(tobject, tpindex, 1); 1162 unlock_tobject: 1163 if (tobject != object) 1164 VM_OBJECT_UNLOCK(tobject); 1165 } 1166 VM_OBJECT_UNLOCK(object); 1167 } 1168 1169 /* 1170 * vm_object_shadow: 1171 * 1172 * Create a new object which is backed by the 1173 * specified existing object range. The source 1174 * object reference is deallocated. 1175 * 1176 * The new object and offset into that object 1177 * are returned in the source parameters. 1178 */ 1179 void 1180 vm_object_shadow( 1181 vm_object_t *object, /* IN/OUT */ 1182 vm_ooffset_t *offset, /* IN/OUT */ 1183 vm_size_t length) 1184 { 1185 vm_object_t source; 1186 vm_object_t result; 1187 1188 source = *object; 1189 1190 /* 1191 * Don't create the new object if the old object isn't shared. 1192 */ 1193 if (source != NULL) { 1194 VM_OBJECT_LOCK(source); 1195 if (source->ref_count == 1 && 1196 source->handle == NULL && 1197 (source->type == OBJT_DEFAULT || 1198 source->type == OBJT_SWAP)) { 1199 VM_OBJECT_UNLOCK(source); 1200 return; 1201 } 1202 VM_OBJECT_UNLOCK(source); 1203 } 1204 1205 /* 1206 * Allocate a new object with the given length. 1207 */ 1208 result = vm_object_allocate(OBJT_DEFAULT, length); 1209 1210 /* 1211 * The new object shadows the source object, adding a reference to it. 1212 * Our caller changes his reference to point to the new object, 1213 * removing a reference to the source object. Net result: no change 1214 * of reference count. 1215 * 1216 * Try to optimize the result object's page color when shadowing 1217 * in order to maintain page coloring consistency in the combined 1218 * shadowed object. 1219 */ 1220 result->backing_object = source; 1221 /* 1222 * Store the offset into the source object, and fix up the offset into 1223 * the new object. 1224 */ 1225 result->backing_object_offset = *offset; 1226 if (source != NULL) { 1227 VM_OBJECT_LOCK(source); 1228 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list); 1229 source->shadow_count++; 1230 source->generation++; 1231 if (length < source->size) 1232 length = source->size; 1233 if (length > PQ_L2_SIZE / 3 + PQ_PRIME1 || 1234 source->generation > 1) 1235 length = PQ_L2_SIZE / 3 + PQ_PRIME1; 1236 result->pg_color = (source->pg_color + 1237 length * source->generation) & PQ_L2_MASK; 1238 result->flags |= source->flags & OBJ_NEEDGIANT; 1239 VM_OBJECT_UNLOCK(source); 1240 next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & 1241 PQ_L2_MASK; 1242 } 1243 1244 1245 /* 1246 * Return the new things 1247 */ 1248 *offset = 0; 1249 *object = result; 1250 } 1251 1252 /* 1253 * vm_object_split: 1254 * 1255 * Split the pages in a map entry into a new object. This affords 1256 * easier removal of unused pages, and keeps object inheritance from 1257 * being a negative impact on memory usage. 1258 */ 1259 void 1260 vm_object_split(vm_map_entry_t entry) 1261 { 1262 vm_page_t m; 1263 vm_object_t orig_object, new_object, source; 1264 vm_pindex_t offidxstart, offidxend; 1265 vm_size_t idx, size; 1266 1267 orig_object = entry->object.vm_object; 1268 if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP) 1269 return; 1270 if (orig_object->ref_count <= 1) 1271 return; 1272 VM_OBJECT_UNLOCK(orig_object); 1273 1274 offidxstart = OFF_TO_IDX(entry->offset); 1275 offidxend = offidxstart + OFF_TO_IDX(entry->end - entry->start); 1276 size = offidxend - offidxstart; 1277 1278 /* 1279 * If swap_pager_copy() is later called, it will convert new_object 1280 * into a swap object. 1281 */ 1282 new_object = vm_object_allocate(OBJT_DEFAULT, size); 1283 1284 VM_OBJECT_LOCK(new_object); 1285 VM_OBJECT_LOCK(orig_object); 1286 source = orig_object->backing_object; 1287 if (source != NULL) { 1288 VM_OBJECT_LOCK(source); 1289 LIST_INSERT_HEAD(&source->shadow_head, 1290 new_object, shadow_list); 1291 source->shadow_count++; 1292 source->generation++; 1293 vm_object_reference_locked(source); /* for new_object */ 1294 vm_object_clear_flag(source, OBJ_ONEMAPPING); 1295 VM_OBJECT_UNLOCK(source); 1296 new_object->backing_object_offset = 1297 orig_object->backing_object_offset + entry->offset; 1298 new_object->backing_object = source; 1299 } 1300 new_object->flags |= orig_object->flags & OBJ_NEEDGIANT; 1301 vm_page_lock_queues(); 1302 for (idx = 0; idx < size; idx++) { 1303 retry: 1304 m = vm_page_lookup(orig_object, offidxstart + idx); 1305 if (m == NULL) 1306 continue; 1307 1308 /* 1309 * We must wait for pending I/O to complete before we can 1310 * rename the page. 1311 * 1312 * We do not have to VM_PROT_NONE the page as mappings should 1313 * not be changed by this operation. 1314 */ 1315 if ((m->flags & PG_BUSY) || m->busy) { 1316 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED); 1317 VM_OBJECT_UNLOCK(orig_object); 1318 VM_OBJECT_UNLOCK(new_object); 1319 msleep(m, &vm_page_queue_mtx, PDROP | PVM, "spltwt", 0); 1320 VM_OBJECT_LOCK(new_object); 1321 VM_OBJECT_LOCK(orig_object); 1322 vm_page_lock_queues(); 1323 goto retry; 1324 } 1325 vm_page_rename(m, new_object, idx); 1326 /* page automatically made dirty by rename and cache handled */ 1327 vm_page_busy(m); 1328 } 1329 vm_page_unlock_queues(); 1330 if (orig_object->type == OBJT_SWAP) { 1331 /* 1332 * swap_pager_copy() can sleep, in which case the orig_object's 1333 * and new_object's locks are released and reacquired. 1334 */ 1335 swap_pager_copy(orig_object, new_object, offidxstart, 0); 1336 } 1337 VM_OBJECT_UNLOCK(orig_object); 1338 vm_page_lock_queues(); 1339 TAILQ_FOREACH(m, &new_object->memq, listq) 1340 vm_page_wakeup(m); 1341 vm_page_unlock_queues(); 1342 VM_OBJECT_UNLOCK(new_object); 1343 entry->object.vm_object = new_object; 1344 entry->offset = 0LL; 1345 vm_object_deallocate(orig_object); 1346 VM_OBJECT_LOCK(new_object); 1347 } 1348 1349 #define OBSC_TEST_ALL_SHADOWED 0x0001 1350 #define OBSC_COLLAPSE_NOWAIT 0x0002 1351 #define OBSC_COLLAPSE_WAIT 0x0004 1352 1353 static int 1354 vm_object_backing_scan(vm_object_t object, int op) 1355 { 1356 int r = 1; 1357 vm_page_t p; 1358 vm_object_t backing_object; 1359 vm_pindex_t backing_offset_index; 1360 1361 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1362 VM_OBJECT_LOCK_ASSERT(object->backing_object, MA_OWNED); 1363 1364 backing_object = object->backing_object; 1365 backing_offset_index = OFF_TO_IDX(object->backing_object_offset); 1366 1367 /* 1368 * Initial conditions 1369 */ 1370 if (op & OBSC_TEST_ALL_SHADOWED) { 1371 /* 1372 * We do not want to have to test for the existence of 1373 * swap pages in the backing object. XXX but with the 1374 * new swapper this would be pretty easy to do. 1375 * 1376 * XXX what about anonymous MAP_SHARED memory that hasn't 1377 * been ZFOD faulted yet? If we do not test for this, the 1378 * shadow test may succeed! XXX 1379 */ 1380 if (backing_object->type != OBJT_DEFAULT) { 1381 return (0); 1382 } 1383 } 1384 if (op & OBSC_COLLAPSE_WAIT) { 1385 vm_object_set_flag(backing_object, OBJ_DEAD); 1386 } 1387 1388 /* 1389 * Our scan 1390 */ 1391 p = TAILQ_FIRST(&backing_object->memq); 1392 while (p) { 1393 vm_page_t next = TAILQ_NEXT(p, listq); 1394 vm_pindex_t new_pindex = p->pindex - backing_offset_index; 1395 1396 if (op & OBSC_TEST_ALL_SHADOWED) { 1397 vm_page_t pp; 1398 1399 /* 1400 * Ignore pages outside the parent object's range 1401 * and outside the parent object's mapping of the 1402 * backing object. 1403 * 1404 * note that we do not busy the backing object's 1405 * page. 1406 */ 1407 if ( 1408 p->pindex < backing_offset_index || 1409 new_pindex >= object->size 1410 ) { 1411 p = next; 1412 continue; 1413 } 1414 1415 /* 1416 * See if the parent has the page or if the parent's 1417 * object pager has the page. If the parent has the 1418 * page but the page is not valid, the parent's 1419 * object pager must have the page. 1420 * 1421 * If this fails, the parent does not completely shadow 1422 * the object and we might as well give up now. 1423 */ 1424 1425 pp = vm_page_lookup(object, new_pindex); 1426 if ( 1427 (pp == NULL || pp->valid == 0) && 1428 !vm_pager_has_page(object, new_pindex, NULL, NULL) 1429 ) { 1430 r = 0; 1431 break; 1432 } 1433 } 1434 1435 /* 1436 * Check for busy page 1437 */ 1438 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) { 1439 vm_page_t pp; 1440 1441 if (op & OBSC_COLLAPSE_NOWAIT) { 1442 if ((p->flags & PG_BUSY) || 1443 !p->valid || 1444 p->busy) { 1445 p = next; 1446 continue; 1447 } 1448 } else if (op & OBSC_COLLAPSE_WAIT) { 1449 if ((p->flags & PG_BUSY) || p->busy) { 1450 vm_page_lock_queues(); 1451 vm_page_flag_set(p, 1452 PG_WANTED | PG_REFERENCED); 1453 VM_OBJECT_UNLOCK(backing_object); 1454 VM_OBJECT_UNLOCK(object); 1455 msleep(p, &vm_page_queue_mtx, 1456 PDROP | PVM, "vmocol", 0); 1457 VM_OBJECT_LOCK(object); 1458 VM_OBJECT_LOCK(backing_object); 1459 /* 1460 * If we slept, anything could have 1461 * happened. Since the object is 1462 * marked dead, the backing offset 1463 * should not have changed so we 1464 * just restart our scan. 1465 */ 1466 p = TAILQ_FIRST(&backing_object->memq); 1467 continue; 1468 } 1469 } 1470 1471 KASSERT( 1472 p->object == backing_object, 1473 ("vm_object_backing_scan: object mismatch") 1474 ); 1475 1476 /* 1477 * Destroy any associated swap 1478 */ 1479 if (backing_object->type == OBJT_SWAP) { 1480 swap_pager_freespace( 1481 backing_object, 1482 p->pindex, 1483 1 1484 ); 1485 } 1486 1487 if ( 1488 p->pindex < backing_offset_index || 1489 new_pindex >= object->size 1490 ) { 1491 /* 1492 * Page is out of the parent object's range, we 1493 * can simply destroy it. 1494 */ 1495 vm_page_lock_queues(); 1496 KASSERT(!pmap_page_is_mapped(p), 1497 ("freeing mapped page %p", p)); 1498 if (p->wire_count == 0) 1499 vm_page_free(p); 1500 else 1501 vm_page_remove(p); 1502 vm_page_unlock_queues(); 1503 p = next; 1504 continue; 1505 } 1506 1507 pp = vm_page_lookup(object, new_pindex); 1508 if ( 1509 pp != NULL || 1510 vm_pager_has_page(object, new_pindex, NULL, NULL) 1511 ) { 1512 /* 1513 * page already exists in parent OR swap exists 1514 * for this location in the parent. Destroy 1515 * the original page from the backing object. 1516 * 1517 * Leave the parent's page alone 1518 */ 1519 vm_page_lock_queues(); 1520 KASSERT(!pmap_page_is_mapped(p), 1521 ("freeing mapped page %p", p)); 1522 if (p->wire_count == 0) 1523 vm_page_free(p); 1524 else 1525 vm_page_remove(p); 1526 vm_page_unlock_queues(); 1527 p = next; 1528 continue; 1529 } 1530 1531 /* 1532 * Page does not exist in parent, rename the 1533 * page from the backing object to the main object. 1534 * 1535 * If the page was mapped to a process, it can remain 1536 * mapped through the rename. 1537 */ 1538 vm_page_lock_queues(); 1539 vm_page_rename(p, object, new_pindex); 1540 vm_page_unlock_queues(); 1541 /* page automatically made dirty by rename */ 1542 } 1543 p = next; 1544 } 1545 return (r); 1546 } 1547 1548 1549 /* 1550 * this version of collapse allows the operation to occur earlier and 1551 * when paging_in_progress is true for an object... This is not a complete 1552 * operation, but should plug 99.9% of the rest of the leaks. 1553 */ 1554 static void 1555 vm_object_qcollapse(vm_object_t object) 1556 { 1557 vm_object_t backing_object = object->backing_object; 1558 1559 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1560 VM_OBJECT_LOCK_ASSERT(backing_object, MA_OWNED); 1561 1562 if (backing_object->ref_count != 1) 1563 return; 1564 1565 vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT); 1566 } 1567 1568 /* 1569 * vm_object_collapse: 1570 * 1571 * Collapse an object with the object backing it. 1572 * Pages in the backing object are moved into the 1573 * parent, and the backing object is deallocated. 1574 */ 1575 void 1576 vm_object_collapse(vm_object_t object) 1577 { 1578 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1579 1580 while (TRUE) { 1581 vm_object_t backing_object; 1582 1583 /* 1584 * Verify that the conditions are right for collapse: 1585 * 1586 * The object exists and the backing object exists. 1587 */ 1588 if ((backing_object = object->backing_object) == NULL) 1589 break; 1590 1591 /* 1592 * we check the backing object first, because it is most likely 1593 * not collapsable. 1594 */ 1595 VM_OBJECT_LOCK(backing_object); 1596 if (backing_object->handle != NULL || 1597 (backing_object->type != OBJT_DEFAULT && 1598 backing_object->type != OBJT_SWAP) || 1599 (backing_object->flags & OBJ_DEAD) || 1600 object->handle != NULL || 1601 (object->type != OBJT_DEFAULT && 1602 object->type != OBJT_SWAP) || 1603 (object->flags & OBJ_DEAD)) { 1604 VM_OBJECT_UNLOCK(backing_object); 1605 break; 1606 } 1607 1608 if ( 1609 object->paging_in_progress != 0 || 1610 backing_object->paging_in_progress != 0 1611 ) { 1612 vm_object_qcollapse(object); 1613 VM_OBJECT_UNLOCK(backing_object); 1614 break; 1615 } 1616 /* 1617 * We know that we can either collapse the backing object (if 1618 * the parent is the only reference to it) or (perhaps) have 1619 * the parent bypass the object if the parent happens to shadow 1620 * all the resident pages in the entire backing object. 1621 * 1622 * This is ignoring pager-backed pages such as swap pages. 1623 * vm_object_backing_scan fails the shadowing test in this 1624 * case. 1625 */ 1626 if (backing_object->ref_count == 1) { 1627 /* 1628 * If there is exactly one reference to the backing 1629 * object, we can collapse it into the parent. 1630 */ 1631 vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT); 1632 1633 /* 1634 * Move the pager from backing_object to object. 1635 */ 1636 if (backing_object->type == OBJT_SWAP) { 1637 /* 1638 * swap_pager_copy() can sleep, in which case 1639 * the backing_object's and object's locks are 1640 * released and reacquired. 1641 */ 1642 swap_pager_copy( 1643 backing_object, 1644 object, 1645 OFF_TO_IDX(object->backing_object_offset), TRUE); 1646 } 1647 /* 1648 * Object now shadows whatever backing_object did. 1649 * Note that the reference to 1650 * backing_object->backing_object moves from within 1651 * backing_object to within object. 1652 */ 1653 LIST_REMOVE(object, shadow_list); 1654 backing_object->shadow_count--; 1655 backing_object->generation++; 1656 if (backing_object->backing_object) { 1657 VM_OBJECT_LOCK(backing_object->backing_object); 1658 LIST_REMOVE(backing_object, shadow_list); 1659 LIST_INSERT_HEAD( 1660 &backing_object->backing_object->shadow_head, 1661 object, shadow_list); 1662 /* 1663 * The shadow_count has not changed. 1664 */ 1665 backing_object->backing_object->generation++; 1666 VM_OBJECT_UNLOCK(backing_object->backing_object); 1667 } 1668 object->backing_object = backing_object->backing_object; 1669 object->backing_object_offset += 1670 backing_object->backing_object_offset; 1671 1672 /* 1673 * Discard backing_object. 1674 * 1675 * Since the backing object has no pages, no pager left, 1676 * and no object references within it, all that is 1677 * necessary is to dispose of it. 1678 */ 1679 KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object)); 1680 VM_OBJECT_UNLOCK(backing_object); 1681 1682 mtx_lock(&vm_object_list_mtx); 1683 TAILQ_REMOVE( 1684 &vm_object_list, 1685 backing_object, 1686 object_list 1687 ); 1688 mtx_unlock(&vm_object_list_mtx); 1689 1690 uma_zfree(obj_zone, backing_object); 1691 1692 object_collapses++; 1693 } else { 1694 vm_object_t new_backing_object; 1695 1696 /* 1697 * If we do not entirely shadow the backing object, 1698 * there is nothing we can do so we give up. 1699 */ 1700 if (vm_object_backing_scan(object, OBSC_TEST_ALL_SHADOWED) == 0) { 1701 VM_OBJECT_UNLOCK(backing_object); 1702 break; 1703 } 1704 1705 /* 1706 * Make the parent shadow the next object in the 1707 * chain. Deallocating backing_object will not remove 1708 * it, since its reference count is at least 2. 1709 */ 1710 LIST_REMOVE(object, shadow_list); 1711 backing_object->shadow_count--; 1712 backing_object->generation++; 1713 1714 new_backing_object = backing_object->backing_object; 1715 if ((object->backing_object = new_backing_object) != NULL) { 1716 VM_OBJECT_LOCK(new_backing_object); 1717 LIST_INSERT_HEAD( 1718 &new_backing_object->shadow_head, 1719 object, 1720 shadow_list 1721 ); 1722 new_backing_object->shadow_count++; 1723 new_backing_object->generation++; 1724 vm_object_reference_locked(new_backing_object); 1725 VM_OBJECT_UNLOCK(new_backing_object); 1726 object->backing_object_offset += 1727 backing_object->backing_object_offset; 1728 } 1729 1730 /* 1731 * Drop the reference count on backing_object. Since 1732 * its ref_count was at least 2, it will not vanish. 1733 */ 1734 backing_object->ref_count--; 1735 VM_OBJECT_UNLOCK(backing_object); 1736 object_bypasses++; 1737 } 1738 1739 /* 1740 * Try again with this object's new backing object. 1741 */ 1742 } 1743 } 1744 1745 /* 1746 * vm_object_page_remove: 1747 * 1748 * Removes all physical pages in the given range from the 1749 * object's list of pages. If the range's end is zero, all 1750 * physical pages from the range's start to the end of the object 1751 * are deleted. 1752 * 1753 * The object must be locked. 1754 */ 1755 void 1756 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end, 1757 boolean_t clean_only) 1758 { 1759 vm_page_t p, next; 1760 1761 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1762 if (object->resident_page_count == 0) 1763 return; 1764 1765 /* 1766 * Since physically-backed objects do not use managed pages, we can't 1767 * remove pages from the object (we must instead remove the page 1768 * references, and then destroy the object). 1769 */ 1770 KASSERT(object->type != OBJT_PHYS, 1771 ("attempt to remove pages from a physical object")); 1772 1773 vm_object_pip_add(object, 1); 1774 again: 1775 vm_page_lock_queues(); 1776 if ((p = TAILQ_FIRST(&object->memq)) != NULL) { 1777 if (p->pindex < start) { 1778 p = vm_page_splay(start, object->root); 1779 if ((object->root = p)->pindex < start) 1780 p = TAILQ_NEXT(p, listq); 1781 } 1782 } 1783 /* 1784 * Assert: the variable p is either (1) the page with the 1785 * least pindex greater than or equal to the parameter pindex 1786 * or (2) NULL. 1787 */ 1788 for (; 1789 p != NULL && (p->pindex < end || end == 0); 1790 p = next) { 1791 next = TAILQ_NEXT(p, listq); 1792 1793 if (p->wire_count != 0) { 1794 pmap_remove_all(p); 1795 if (!clean_only) 1796 p->valid = 0; 1797 continue; 1798 } 1799 if (vm_page_sleep_if_busy(p, TRUE, "vmopar")) 1800 goto again; 1801 if (clean_only && p->valid) { 1802 pmap_page_protect(p, VM_PROT_READ | VM_PROT_EXECUTE); 1803 if (p->valid & p->dirty) 1804 continue; 1805 } 1806 pmap_remove_all(p); 1807 vm_page_free(p); 1808 } 1809 vm_page_unlock_queues(); 1810 vm_object_pip_wakeup(object); 1811 } 1812 1813 /* 1814 * Routine: vm_object_coalesce 1815 * Function: Coalesces two objects backing up adjoining 1816 * regions of memory into a single object. 1817 * 1818 * returns TRUE if objects were combined. 1819 * 1820 * NOTE: Only works at the moment if the second object is NULL - 1821 * if it's not, which object do we lock first? 1822 * 1823 * Parameters: 1824 * prev_object First object to coalesce 1825 * prev_offset Offset into prev_object 1826 * prev_size Size of reference to prev_object 1827 * next_size Size of reference to the second object 1828 * 1829 * Conditions: 1830 * The object must *not* be locked. 1831 */ 1832 boolean_t 1833 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset, 1834 vm_size_t prev_size, vm_size_t next_size) 1835 { 1836 vm_pindex_t next_pindex; 1837 1838 if (prev_object == NULL) 1839 return (TRUE); 1840 VM_OBJECT_LOCK(prev_object); 1841 if (prev_object->type != OBJT_DEFAULT && 1842 prev_object->type != OBJT_SWAP) { 1843 VM_OBJECT_UNLOCK(prev_object); 1844 return (FALSE); 1845 } 1846 1847 /* 1848 * Try to collapse the object first 1849 */ 1850 vm_object_collapse(prev_object); 1851 1852 /* 1853 * Can't coalesce if: . more than one reference . paged out . shadows 1854 * another object . has a copy elsewhere (any of which mean that the 1855 * pages not mapped to prev_entry may be in use anyway) 1856 */ 1857 if (prev_object->backing_object != NULL) { 1858 VM_OBJECT_UNLOCK(prev_object); 1859 return (FALSE); 1860 } 1861 1862 prev_size >>= PAGE_SHIFT; 1863 next_size >>= PAGE_SHIFT; 1864 next_pindex = OFF_TO_IDX(prev_offset) + prev_size; 1865 1866 if ((prev_object->ref_count > 1) && 1867 (prev_object->size != next_pindex)) { 1868 VM_OBJECT_UNLOCK(prev_object); 1869 return (FALSE); 1870 } 1871 1872 /* 1873 * Remove any pages that may still be in the object from a previous 1874 * deallocation. 1875 */ 1876 if (next_pindex < prev_object->size) { 1877 vm_object_page_remove(prev_object, 1878 next_pindex, 1879 next_pindex + next_size, FALSE); 1880 if (prev_object->type == OBJT_SWAP) 1881 swap_pager_freespace(prev_object, 1882 next_pindex, next_size); 1883 } 1884 1885 /* 1886 * Extend the object if necessary. 1887 */ 1888 if (next_pindex + next_size > prev_object->size) 1889 prev_object->size = next_pindex + next_size; 1890 1891 VM_OBJECT_UNLOCK(prev_object); 1892 return (TRUE); 1893 } 1894 1895 void 1896 vm_object_set_writeable_dirty(vm_object_t object) 1897 { 1898 struct vnode *vp; 1899 1900 VM_OBJECT_LOCK_ASSERT(object, MA_OWNED); 1901 if ((object->flags & (OBJ_MIGHTBEDIRTY|OBJ_WRITEABLE)) == 1902 (OBJ_MIGHTBEDIRTY|OBJ_WRITEABLE)) 1903 return; 1904 vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY); 1905 if (object->type == OBJT_VNODE && 1906 (vp = (struct vnode *)object->handle) != NULL) { 1907 VI_LOCK(vp); 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