sys/vm/vm_object.c

   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 "opt_vm.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/systm.h>
  72 #include <sys/lock.h>
  73 #include <sys/mman.h>
  74 #include <sys/mount.h>
  75 #include <sys/kernel.h>
  76 #include <sys/sysctl.h>
  77 #include <sys/mutex.h>
  78 #include <sys/proc.h>           /* for curproc, pageproc */
  79 #include <sys/socket.h>
  80 #include <sys/resourcevar.h>
  81 #include <sys/rwlock.h>
  82 #include <sys/user.h>
  83 #include <sys/vnode.h>
  84 #include <sys/vmmeter.h>
  85 #include <sys/sx.h>
  86
  87 #include <vm/vm.h>
  88 #include <vm/vm_param.h>
  89 #include <vm/pmap.h>
  90 #include <vm/vm_map.h>
  91 #include <vm/vm_object.h>
  92 #include <vm/vm_page.h>
  93 #include <vm/vm_pageout.h>
  94 #include <vm/vm_pager.h>
  95 #include <vm/swap_pager.h>
  96 #include <vm/vm_kern.h>
  97 #include <vm/vm_extern.h>
  98 #include <vm/vm_radix.h>
  99 #include <vm/vm_reserv.h>
 100 #include <vm/uma.h>
 101
 102 static int old_msync;
 103 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
 104     "Use old (insecure) msync behavior");
 105
 106 static int      vm_object_page_collect_flush(vm_object_t object, vm_page_t p,
 107                     int pagerflags, int flags, boolean_t *clearobjflags,
 108                     boolean_t *eio);
 109 static boolean_t vm_object_page_remove_write(vm_page_t p, int flags,
 110                     boolean_t *clearobjflags);
 111 static void     vm_object_qcollapse(vm_object_t object);
 112 static void     vm_object_vndeallocate(vm_object_t object);
 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 SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD, 0,
 147     "VM object stats");
 148
 149 static long object_collapses;
 150 SYSCTL_LONG(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD,
 151     &object_collapses, 0, "VM object collapses");
 152
 153 static long object_bypasses;
 154 SYSCTL_LONG(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD,
 155     &object_bypasses, 0, "VM object bypasses");
 156
 157 static uma_zone_t obj_zone;
 158
 159 static int vm_object_zinit(void *mem, int size, int flags);
 160
 161 #ifdef INVARIANTS
 162 static void vm_object_zdtor(void *mem, int size, void *arg);
 163
 164 static void
 165 vm_object_zdtor(void *mem, int size, void *arg)
 166 {
 167         vm_object_t object;
 168
 169         object = (vm_object_t)mem;
 170         KASSERT(object->ref_count == 0,
 171             ("object %p ref_count = %d", object, object->ref_count));
 172         KASSERT(TAILQ_EMPTY(&object->memq),
 173             ("object %p has resident pages in its memq", object));
 174         KASSERT(vm_radix_is_empty(&object->rtree),
 175             ("object %p has resident pages in its trie", object));
 176 #if VM_NRESERVLEVEL > 0
 177         KASSERT(LIST_EMPTY(&object->rvq),
 178             ("object %p has reservations",
 179             object));
 180 #endif
 181         KASSERT(vm_object_cache_is_empty(object),
 182             ("object %p has cached pages",
 183             object));
 184         KASSERT(object->paging_in_progress == 0,
 185             ("object %p paging_in_progress = %d",
 186             object, object->paging_in_progress));
 187         KASSERT(object->resident_page_count == 0,
 188             ("object %p resident_page_count = %d",
 189             object, object->resident_page_count));
 190         KASSERT(object->shadow_count == 0,
 191             ("object %p shadow_count = %d",
 192             object, object->shadow_count));
 193         KASSERT(object->type == OBJT_DEAD,
 194             ("object %p has non-dead type %d",
 195             object, object->type));
 196 }
 197 #endif
 198
 199 static int
 200 vm_object_zinit(void *mem, int size, int flags)
 201 {
 202         vm_object_t object;
 203
 204         object = (vm_object_t)mem;
 205         bzero(&object->lock, sizeof(object->lock));
 206         rw_init_flags(&object->lock, "vm object", RW_DUPOK);
 207
 208         /* These are true for any object that has been freed */
 209         object->type = OBJT_DEAD;
 210         object->ref_count = 0;
 211         object->rtree.rt_root = 0;
 212         object->rtree.rt_flags = 0;
 213         object->paging_in_progress = 0;
 214         object->resident_page_count = 0;
 215         object->shadow_count = 0;
 216         object->cache.rt_root = 0;
 217         object->cache.rt_flags = 0;
 218
 219         mtx_lock(&vm_object_list_mtx);
 220         TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
 221         mtx_unlock(&vm_object_list_mtx);
 222         return (0);
 223 }
 224
 225 static void
 226 _vm_object_allocate(objtype_t type, vm_pindex_t size, vm_object_t object)
 227 {
 228
 229         TAILQ_INIT(&object->memq);
 230         LIST_INIT(&object->shadow_head);
 231
 232         object->type = type;
 233         switch (type) {
 234         case OBJT_DEAD:
 235                 panic("_vm_object_allocate: can't create OBJT_DEAD");
 236         case OBJT_DEFAULT:
 237         case OBJT_SWAP:
 238                 object->flags = OBJ_ONEMAPPING;
 239                 break;
 240         case OBJT_DEVICE:
 241         case OBJT_SG:
 242                 object->flags = OBJ_FICTITIOUS | OBJ_UNMANAGED;
 243                 break;
 244         case OBJT_MGTDEVICE:
 245                 object->flags = OBJ_FICTITIOUS;
 246                 break;
 247         case OBJT_PHYS:
 248                 object->flags = OBJ_UNMANAGED;
 249                 break;
 250         case OBJT_VNODE:
 251                 object->flags = 0;
 252                 break;
 253         default:
 254                 panic("_vm_object_allocate: type %d is undefined", type);
 255         }
 256         object->size = size;
 257         object->generation = 1;
 258         object->ref_count = 1;
 259         object->memattr = VM_MEMATTR_DEFAULT;
 260         object->cred = NULL;
 261         object->charge = 0;
 262         object->handle = NULL;
 263         object->backing_object = NULL;
 264         object->backing_object_offset = (vm_ooffset_t) 0;
 265 #if VM_NRESERVLEVEL > 0
 266         LIST_INIT(&object->rvq);
 267 #endif
 268 }
 269
 270 /*
 271  *      vm_object_init:
 272  *
 273  *      Initialize the VM objects module.
 274  */
 275 void
 276 vm_object_init(void)
 277 {
 278         TAILQ_INIT(&vm_object_list);
 279         mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
 280
 281         rw_init(&kernel_object->lock, "kernel vm object");
 282         _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
 283             kernel_object);
 284 #if VM_NRESERVLEVEL > 0
 285         kernel_object->flags |= OBJ_COLORED;
 286         kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
 287 #endif
 288
 289         rw_init(&kmem_object->lock, "kmem vm object");
 290         _vm_object_allocate(OBJT_PHYS, OFF_TO_IDX(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS),
 291             kmem_object);
 292 #if VM_NRESERVLEVEL > 0
 293         kmem_object->flags |= OBJ_COLORED;
 294         kmem_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
 295 #endif
 296
 297         /*
 298          * The lock portion of struct vm_object must be type stable due
 299          * to vm_pageout_fallback_object_lock locking a vm object
 300          * without holding any references to it.
 301          */
 302         obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
 303 #ifdef INVARIANTS
 304             vm_object_zdtor,
 305 #else
 306             NULL,
 307 #endif
 308             vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
 309
 310         vm_radix_init();
 311 }
 312
 313 void
 314 vm_object_clear_flag(vm_object_t object, u_short bits)
 315 {
 316
 317         VM_OBJECT_ASSERT_WLOCKED(object);
 318         object->flags &= ~bits;
 319 }
 320
 321 /*
 322  *      Sets the default memory attribute for the specified object.  Pages
 323  *      that are allocated to this object are by default assigned this memory
 324  *      attribute.
 325  *
 326  *      Presently, this function must be called before any pages are allocated
 327  *      to the object.  In the future, this requirement may be relaxed for
 328  *      "default" and "swap" objects.
 329  */
 330 int
 331 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr)
 332 {
 333
 334         VM_OBJECT_ASSERT_WLOCKED(object);
 335         switch (object->type) {
 336         case OBJT_DEFAULT:
 337         case OBJT_DEVICE:
 338         case OBJT_MGTDEVICE:
 339         case OBJT_PHYS:
 340         case OBJT_SG:
 341         case OBJT_SWAP:
 342         case OBJT_VNODE:
 343                 if (!TAILQ_EMPTY(&object->memq))
 344                         return (KERN_FAILURE);
 345                 break;
 346         case OBJT_DEAD:
 347                 return (KERN_INVALID_ARGUMENT);
 348         default:
 349                 panic("vm_object_set_memattr: object %p is of undefined type",
 350                     object);
 351         }
 352         object->memattr = memattr;
 353         return (KERN_SUCCESS);
 354 }
 355
 356 void
 357 vm_object_pip_add(vm_object_t object, short i)
 358 {
 359
 360         VM_OBJECT_ASSERT_WLOCKED(object);
 361         object->paging_in_progress += i;
 362 }
 363
 364 void
 365 vm_object_pip_subtract(vm_object_t object, short i)
 366 {
 367
 368         VM_OBJECT_ASSERT_WLOCKED(object);
 369         object->paging_in_progress -= i;
 370 }
 371
 372 void
 373 vm_object_pip_wakeup(vm_object_t object)
 374 {
 375
 376         VM_OBJECT_ASSERT_WLOCKED(object);
 377         object->paging_in_progress--;
 378         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 379                 vm_object_clear_flag(object, OBJ_PIPWNT);
 380                 wakeup(object);
 381         }
 382 }
 383
 384 void
 385 vm_object_pip_wakeupn(vm_object_t object, short i)
 386 {
 387
 388         VM_OBJECT_ASSERT_WLOCKED(object);
 389         if (i)
 390                 object->paging_in_progress -= i;
 391         if ((object->flags & OBJ_PIPWNT) && object->paging_in_progress == 0) {
 392                 vm_object_clear_flag(object, OBJ_PIPWNT);
 393                 wakeup(object);
 394         }
 395 }
 396
 397 void
 398 vm_object_pip_wait(vm_object_t object, char *waitid)
 399 {
 400
 401         VM_OBJECT_ASSERT_WLOCKED(object);
 402         while (object->paging_in_progress) {
 403                 object->flags |= OBJ_PIPWNT;
 404                 VM_OBJECT_SLEEP(object, object, PVM, waitid, 0);
 405         }
 406 }
 407
 408 /*
 409  *      vm_object_allocate:
 410  *
 411  *      Returns a new object with the given size.
 412  */
 413 vm_object_t
 414 vm_object_allocate(objtype_t type, vm_pindex_t size)
 415 {
 416         vm_object_t object;
 417
 418         object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK);
 419         _vm_object_allocate(type, size, object);
 420         return (object);
 421 }
 422
 423
 424 /*
 425  *      vm_object_reference:
 426  *
 427  *      Gets another reference to the given object.  Note: OBJ_DEAD
 428  *      objects can be referenced during final cleaning.
 429  */
 430 void
 431 vm_object_reference(vm_object_t object)
 432 {
 433         if (object == NULL)
 434                 return;
 435         VM_OBJECT_WLOCK(object);
 436         vm_object_reference_locked(object);
 437         VM_OBJECT_WUNLOCK(object);
 438 }
 439
 440 /*
 441  *      vm_object_reference_locked:
 442  *
 443  *      Gets another reference to the given object.
 444  *
 445  *      The object must be locked.
 446  */
 447 void
 448 vm_object_reference_locked(vm_object_t object)
 449 {
 450         struct vnode *vp;
 451
 452         VM_OBJECT_ASSERT_WLOCKED(object);
 453         object->ref_count++;
 454         if (object->type == OBJT_VNODE) {
 455                 vp = object->handle;
 456                 vref(vp);
 457         }
 458 }
 459
 460 /*
 461  * Handle deallocating an object of type OBJT_VNODE.
 462  */
 463 static void
 464 vm_object_vndeallocate(vm_object_t object)
 465 {
 466         struct vnode *vp = (struct vnode *) object->handle;
 467
 468         VM_OBJECT_ASSERT_WLOCKED(object);
 469         KASSERT(object->type == OBJT_VNODE,
 470             ("vm_object_vndeallocate: not a vnode object"));
 471         KASSERT(vp != NULL, ("vm_object_vndeallocate: missing vp"));
 472 #ifdef INVARIANTS
 473         if (object->ref_count == 0) {
 474                 vprint("vm_object_vndeallocate", vp);
 475                 panic("vm_object_vndeallocate: bad object reference count");
 476         }
 477 #endif
 478
 479         /*
 480          * The test for text of vp vnode does not need a bypass to
 481          * reach right VV_TEXT there, since it is obtained from
 482          * object->handle.
 483          */
 484         if (object->ref_count > 1 || (vp->v_vflag & VV_TEXT) == 0) {
 485                 object->ref_count--;
 486                 VM_OBJECT_WUNLOCK(object);
 487                 /* vrele may need the vnode lock. */
 488                 vrele(vp);
 489         } else {
 490                 vhold(vp);
 491                 VM_OBJECT_WUNLOCK(object);
 492                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 493                 vdrop(vp);
 494                 VM_OBJECT_WLOCK(object);
 495                 object->ref_count--;
 496                 if (object->type == OBJT_DEAD) {
 497                         VM_OBJECT_WUNLOCK(object);
 498                         VOP_UNLOCK(vp, 0);
 499                 } else {
 500                         if (object->ref_count == 0)
 501                                 VOP_UNSET_TEXT(vp);
 502                         VM_OBJECT_WUNLOCK(object);
 503                         vput(vp);
 504                 }
 505         }
 506 }
 507
 508 /*
 509  *      vm_object_deallocate:
 510  *
 511  *      Release a reference to the specified object,
 512  *      gained either through a vm_object_allocate
 513  *      or a vm_object_reference call.  When all references
 514  *      are gone, storage associated with this object
 515  *      may be relinquished.
 516  *
 517  *      No object may be locked.
 518  */
 519 void
 520 vm_object_deallocate(vm_object_t object)
 521 {
 522         vm_object_t temp;
 523         struct vnode *vp;
 524
 525         while (object != NULL) {
 526                 VM_OBJECT_WLOCK(object);
 527                 if (object->type == OBJT_VNODE) {
 528                         vm_object_vndeallocate(object);
 529                         return;
 530                 }
 531
 532                 KASSERT(object->ref_count != 0,
 533                         ("vm_object_deallocate: object deallocated too many times: %d", object->type));
 534
 535                 /*
 536                  * If the reference count goes to 0 we start calling
 537                  * vm_object_terminate() on the object chain.
 538                  * A ref count of 1 may be a special case depending on the
 539                  * shadow count being 0 or 1.
 540                  */
 541                 object->ref_count--;
 542                 if (object->ref_count > 1) {
 543                         VM_OBJECT_WUNLOCK(object);
 544                         return;
 545                 } else if (object->ref_count == 1) {
 546                         if (object->type == OBJT_SWAP &&
 547                             (object->flags & OBJ_TMPFS) != 0) {
 548                                 vp = object->un_pager.swp.swp_tmpfs;
 549                                 vhold(vp);
 550                                 VM_OBJECT_WUNLOCK(object);
 551                                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
 552                                 VM_OBJECT_WLOCK(object);
 553                                 if (object->type == OBJT_DEAD ||
 554                                     object->ref_count != 1) {
 555                                         VM_OBJECT_WUNLOCK(object);
 556                                         VOP_UNLOCK(vp, 0);
 557                                         vdrop(vp);
 558                                         return;
 559                                 }
 560                                 if ((object->flags & OBJ_TMPFS) != 0)
 561                                         VOP_UNSET_TEXT(vp);
 562                                 VOP_UNLOCK(vp, 0);
 563                                 vdrop(vp);
 564                         }
 565                         if (object->shadow_count == 0 &&
 566                             object->handle == NULL &&
 567                             (object->type == OBJT_DEFAULT ||
 568                             (object->type == OBJT_SWAP &&
 569                             (object->flags & OBJ_TMPFS_NODE) == 0))) {
 570                                 vm_object_set_flag(object, OBJ_ONEMAPPING);
 571                         } else if ((object->shadow_count == 1) &&
 572                             (object->handle == NULL) &&
 573                             (object->type == OBJT_DEFAULT ||
 574                              object->type == OBJT_SWAP)) {
 575                                 vm_object_t robject;
 576
 577                                 robject = LIST_FIRST(&object->shadow_head);
 578                                 KASSERT(robject != NULL,
 579                                     ("vm_object_deallocate: ref_count: %d, shadow_count: %d",
 580                                          object->ref_count,
 581                                          object->shadow_count));
 582                                 KASSERT((robject->flags & OBJ_TMPFS_NODE) == 0,
 583                                     ("shadowed tmpfs v_object %p", object));
 584                                 if (!VM_OBJECT_TRYWLOCK(robject)) {
 585                                         /*
 586                                          * Avoid a potential deadlock.
 587                                          */
 588                                         object->ref_count++;
 589                                         VM_OBJECT_WUNLOCK(object);
 590                                         /*
 591                                          * More likely than not the thread
 592                                          * holding robject's lock has lower
 593                                          * priority than the current thread.
 594                                          * Let the lower priority thread run.
 595                                          */
 596                                         pause("vmo_de", 1);
 597                                         continue;
 598                                 }
 599                                 /*
 600                                  * Collapse object into its shadow unless its
 601                                  * shadow is dead.  In that case, object will
 602                                  * be deallocated by the thread that is
 603                                  * deallocating its shadow.
 604                                  */
 605                                 if ((robject->flags & OBJ_DEAD) == 0 &&
 606                                     (robject->handle == NULL) &&
 607                                     (robject->type == OBJT_DEFAULT ||
 608                                      robject->type == OBJT_SWAP)) {
 609
 610                                         robject->ref_count++;
 611 retry:
 612                                         if (robject->paging_in_progress) {
 613                                                 VM_OBJECT_WUNLOCK(object);
 614                                                 vm_object_pip_wait(robject,
 615                                                     "objde1");
 616                                                 temp = robject->backing_object;
 617                                                 if (object == temp) {
 618                                                         VM_OBJECT_WLOCK(object);
 619                                                         goto retry;
 620                                                 }
 621                                         } else if (object->paging_in_progress) {
 622                                                 VM_OBJECT_WUNLOCK(robject);
 623                                                 object->flags |= OBJ_PIPWNT;
 624                                                 VM_OBJECT_SLEEP(object, object,
 625                                                     PDROP | PVM, "objde2", 0);
 626                                                 VM_OBJECT_WLOCK(robject);
 627                                                 temp = robject->backing_object;
 628                                                 if (object == temp) {
 629                                                         VM_OBJECT_WLOCK(object);
 630                                                         goto retry;
 631                                                 }
 632                                         } else
 633                                                 VM_OBJECT_WUNLOCK(object);
 634
 635                                         if (robject->ref_count == 1) {
 636                                                 robject->ref_count--;
 637                                                 object = robject;
 638                                                 goto doterm;
 639                                         }
 640                                         object = robject;
 641                                         vm_object_collapse(object);
 642                                         VM_OBJECT_WUNLOCK(object);
 643                                         continue;
 644                                 }
 645                                 VM_OBJECT_WUNLOCK(robject);
 646                         }
 647                         VM_OBJECT_WUNLOCK(object);
 648                         return;
 649                 }
 650 doterm:
 651                 temp = object->backing_object;
 652                 if (temp != NULL) {
 653                         KASSERT((object->flags & OBJ_TMPFS_NODE) == 0,
 654                             ("shadowed tmpfs v_object 2 %p", object));
 655                         VM_OBJECT_WLOCK(temp);
 656                         LIST_REMOVE(object, shadow_list);
 657                         temp->shadow_count--;
 658                         VM_OBJECT_WUNLOCK(temp);
 659                         object->backing_object = NULL;
 660                 }
 661                 /*
 662                  * Don't double-terminate, we could be in a termination
 663                  * recursion due to the terminate having to sync data
 664                  * to disk.
 665                  */
 666                 if ((object->flags & OBJ_DEAD) == 0)
 667                         vm_object_terminate(object);
 668                 else
 669                         VM_OBJECT_WUNLOCK(object);
 670                 object = temp;
 671         }
 672 }
 673
 674 /*
 675  *      vm_object_destroy removes the object from the global object list
 676  *      and frees the space for the object.
 677  */
 678 void
 679 vm_object_destroy(vm_object_t object)
 680 {
 681
 682         /*
 683          * Release the allocation charge.
 684          */
 685         if (object->cred != NULL) {
 686                 swap_release_by_cred(object->charge, object->cred);
 687                 object->charge = 0;
 688                 crfree(object->cred);
 689                 object->cred = NULL;
 690         }
 691
 692         /*
 693          * Free the space for the object.
 694          */
 695         uma_zfree(obj_zone, object);
 696 }
 697
 698 /*
 699  *      vm_object_terminate actually destroys the specified object, freeing
 700  *      up all previously used resources.
 701  *
 702  *      The object must be locked.
 703  *      This routine may block.
 704  */
 705 void
 706 vm_object_terminate(vm_object_t object)
 707 {
 708         vm_page_t p, p_next;
 709
 710         VM_OBJECT_ASSERT_WLOCKED(object);
 711
 712         /*
 713          * Make sure no one uses us.
 714          */
 715         vm_object_set_flag(object, OBJ_DEAD);
 716
 717         /*
 718          * wait for the pageout daemon to be done with the object
 719          */
 720         vm_object_pip_wait(object, "objtrm");
 721
 722         KASSERT(!object->paging_in_progress,
 723                 ("vm_object_terminate: pageout in progress"));
 724
 725         /*
 726          * Clean and free the pages, as appropriate. All references to the
 727          * object are gone, so we don't need to lock it.
 728          */
 729         if (object->type == OBJT_VNODE) {
 730                 struct vnode *vp = (struct vnode *)object->handle;
 731
 732                 /*
 733                  * Clean pages and flush buffers.
 734                  */
 735                 vm_object_page_clean(object, 0, 0, OBJPC_SYNC);
 736                 VM_OBJECT_WUNLOCK(object);
 737
 738                 vinvalbuf(vp, V_SAVE, 0, 0);
 739
 740                 BO_LOCK(&vp->v_bufobj);
 741                 vp->v_bufobj.bo_flag |= BO_DEAD;
 742                 BO_UNLOCK(&vp->v_bufobj);
 743
 744                 VM_OBJECT_WLOCK(object);
 745         }
 746
 747         KASSERT(object->ref_count == 0,
 748                 ("vm_object_terminate: object with references, ref_count=%d",
 749                 object->ref_count));
 750
 751         /*
 752          * Free any remaining pageable pages.  This also removes them from the
 753          * paging queues.  However, don't free wired pages, just remove them
 754          * from the object.  Rather than incrementally removing each page from
 755          * the object, the page and object are reset to any empty state.
 756          */
 757         TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) {
 758                 vm_page_assert_unbusied(p);
 759                 vm_page_lock(p);
 760                 /*
 761                  * Optimize the page's removal from the object by resetting
 762                  * its "object" field.  Specifically, if the page is not
 763                  * wired, then the effect of this assignment is that
 764                  * vm_page_free()'s call to vm_page_remove() will return
 765                  * immediately without modifying the page or the object.
 766                  */
 767                 p->object = NULL;
 768                 if (p->wire_count == 0) {
 769                         vm_page_free(p);
 770                         PCPU_INC(cnt.v_pfree);
 771                 }
 772                 vm_page_unlock(p);
 773         }
 774         /*
 775          * If the object contained any pages, then reset it to an empty state.
 776          * None of the object's fields, including "resident_page_count", were
 777          * modified by the preceding loop.
 778          */
 779         if (object->resident_page_count != 0) {
 780                 vm_radix_reclaim_allnodes(&object->rtree);
 781                 TAILQ_INIT(&object->memq);
 782                 object->resident_page_count = 0;
 783                 if (object->type == OBJT_VNODE)
 784                         vdrop(object->handle);
 785         }
 786
 787 #if VM_NRESERVLEVEL > 0
 788         if (__predict_false(!LIST_EMPTY(&object->rvq)))
 789                 vm_reserv_break_all(object);
 790 #endif
 791         if (__predict_false(!vm_object_cache_is_empty(object)))
 792                 vm_page_cache_free(object, 0, 0);
 793
 794         KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT ||
 795             object->type == OBJT_SWAP,
 796             ("%s: non-swap obj %p has cred", __func__, object));
 797
 798         /*
 799          * Let the pager know object is dead.
 800          */
 801         vm_pager_deallocate(object);
 802         VM_OBJECT_WUNLOCK(object);
 803
 804         vm_object_destroy(object);
 805 }
 806
 807 /*
 808  * Make the page read-only so that we can clear the object flags.  However, if
 809  * this is a nosync mmap then the object is likely to stay dirty so do not
 810  * mess with the page and do not clear the object flags.  Returns TRUE if the
 811  * page should be flushed, and FALSE otherwise.
 812  */
 813 static boolean_t
 814 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *clearobjflags)
 815 {
 816
 817         /*
 818          * If we have been asked to skip nosync pages and this is a
 819          * nosync page, skip it.  Note that the object flags were not
 820          * cleared in this case so we do not have to set them.
 821          */
 822         if ((flags & OBJPC_NOSYNC) != 0 && (p->oflags & VPO_NOSYNC) != 0) {
 823                 *clearobjflags = FALSE;
 824                 return (FALSE);
 825         } else {
 826                 pmap_remove_write(p);
 827                 return (p->dirty != 0);
 828         }
 829 }
 830
 831 /*
 832  *      vm_object_page_clean
 833  *
 834  *      Clean all dirty pages in the specified range of object.  Leaves page
 835  *      on whatever queue it is currently on.   If NOSYNC is set then do not
 836  *      write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC),
 837  *      leaving the object dirty.
 838  *
 839  *      When stuffing pages asynchronously, allow clustering.  XXX we need a
 840  *      synchronous clustering mode implementation.
 841  *
 842  *      Odd semantics: if start == end, we clean everything.
 843  *
 844  *      The object must be locked.
 845  *
 846  *      Returns FALSE if some page from the range was not written, as
 847  *      reported by the pager, and TRUE otherwise.
 848  */
 849 boolean_t
 850 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end,
 851     int flags)
 852 {
 853         vm_page_t np, p;
 854         vm_pindex_t pi, tend, tstart;
 855         int curgeneration, n, pagerflags;
 856         boolean_t clearobjflags, eio, res;
 857
 858         VM_OBJECT_ASSERT_WLOCKED(object);
 859
 860         /*
 861          * The OBJ_MIGHTBEDIRTY flag is only set for OBJT_VNODE
 862          * objects.  The check below prevents the function from
 863          * operating on non-vnode objects.
 864          */
 865         if ((object->flags & OBJ_MIGHTBEDIRTY) == 0 ||
 866             object->resident_page_count == 0)
 867                 return (TRUE);
 868
 869         pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ?
 870             VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
 871         pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0;
 872
 873         tstart = OFF_TO_IDX(start);
 874         tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK);
 875         clearobjflags = tstart == 0 && tend >= object->size;
 876         res = TRUE;
 877
 878 rescan:
 879         curgeneration = object->generation;
 880
 881         for (p = vm_page_find_least(object, tstart); p != NULL; p = np) {
 882                 pi = p->pindex;
 883                 if (pi >= tend)
 884                         break;
 885                 np = TAILQ_NEXT(p, listq);
 886                 if (p->valid == 0)
 887                         continue;
 888                 if (vm_page_sleep_if_busy(p, "vpcwai")) {
 889                         if (object->generation != curgeneration) {
 890                                 if ((flags & OBJPC_SYNC) != 0)
 891                                         goto rescan;
 892                                 else
 893                                         clearobjflags = FALSE;
 894                         }
 895                         np = vm_page_find_least(object, pi);
 896                         continue;
 897                 }
 898                 if (!vm_object_page_remove_write(p, flags, &clearobjflags))
 899                         continue;
 900
 901                 n = vm_object_page_collect_flush(object, p, pagerflags,
 902                     flags, &clearobjflags, &eio);
 903                 if (eio) {
 904                         res = FALSE;
 905                         clearobjflags = FALSE;
 906                 }
 907                 if (object->generation != curgeneration) {
 908                         if ((flags & OBJPC_SYNC) != 0)
 909                                 goto rescan;
 910                         else
 911                                 clearobjflags = FALSE;
 912                 }
 913
 914                 /*
 915                  * If the VOP_PUTPAGES() did a truncated write, so
 916                  * that even the first page of the run is not fully
 917                  * written, vm_pageout_flush() returns 0 as the run
 918                  * length.  Since the condition that caused truncated
 919                  * write may be permanent, e.g. exhausted free space,
 920                  * accepting n == 0 would cause an infinite loop.
 921                  *
 922                  * Forwarding the iterator leaves the unwritten page
 923                  * behind, but there is not much we can do there if
 924                  * filesystem refuses to write it.
 925                  */
 926                 if (n == 0) {
 927                         n = 1;
 928                         clearobjflags = FALSE;
 929                 }
 930                 np = vm_page_find_least(object, pi + n);
 931         }
 932 #if 0
 933         VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0);
 934 #endif
 935
 936         if (clearobjflags)
 937                 vm_object_clear_flag(object, OBJ_MIGHTBEDIRTY);
 938         return (res);
 939 }
 940
 941 static int
 942 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags,
 943     int flags, boolean_t *clearobjflags, boolean_t *eio)
 944 {
 945         vm_page_t ma[vm_pageout_page_count], p_first, tp;
 946         int count, i, mreq, runlen;
 947
 948         vm_page_lock_assert(p, MA_NOTOWNED);
 949         VM_OBJECT_ASSERT_WLOCKED(object);
 950
 951         count = 1;
 952         mreq = 0;
 953
 954         for (tp = p; count < vm_pageout_page_count; count++) {
 955                 tp = vm_page_next(tp);
 956                 if (tp == NULL || vm_page_busied(tp))
 957                         break;
 958                 if (!vm_object_page_remove_write(tp, flags, clearobjflags))
 959                         break;
 960         }
 961
 962         for (p_first = p; count < vm_pageout_page_count; count++) {
 963                 tp = vm_page_prev(p_first);
 964                 if (tp == NULL || vm_page_busied(tp))
 965                         break;
 966                 if (!vm_object_page_remove_write(tp, flags, clearobjflags))
 967                         break;
 968                 p_first = tp;
 969                 mreq++;
 970         }
 971
 972         for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
 973                 ma[i] = tp;
 974
 975         vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
 976         return (runlen);
 977 }
 978
 979 /*
 980  * Note that there is absolutely no sense in writing out
 981  * anonymous objects, so we track down the vnode object
 982  * to write out.
 983  * We invalidate (remove) all pages from the address space
 984  * for semantic correctness.
 985  *
 986  * If the backing object is a device object with unmanaged pages, then any
 987  * mappings to the specified range of pages must be removed before this
 988  * function is called.
 989  *
 990  * Note: certain anonymous maps, such as MAP_NOSYNC maps,
 991  * may start out with a NULL object.
 992  */
 993 boolean_t
 994 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
 995     boolean_t syncio, boolean_t invalidate)
 996 {
 997         vm_object_t backing_object;
 998         struct vnode *vp;
 999         struct mount *mp;
1000         int error, flags, fsync_after;
1001         boolean_t res;
1002
1003         if (object == NULL)
1004                 return (TRUE);
1005         res = TRUE;
1006         error = 0;
1007         VM_OBJECT_WLOCK(object);
1008         while ((backing_object = object->backing_object) != NULL) {
1009                 VM_OBJECT_WLOCK(backing_object);
1010                 offset += object->backing_object_offset;
1011                 VM_OBJECT_WUNLOCK(object);
1012                 object = backing_object;
1013                 if (object->size < OFF_TO_IDX(offset + size))
1014                         size = IDX_TO_OFF(object->size) - offset;
1015         }
1016         /*
1017          * Flush pages if writing is allowed, invalidate them
1018          * if invalidation requested.  Pages undergoing I/O
1019          * will be ignored by vm_object_page_remove().
1020          *
1021          * We cannot lock the vnode and then wait for paging
1022          * to complete without deadlocking against vm_fault.
1023          * Instead we simply call vm_object_page_remove() and
1024          * allow it to block internally on a page-by-page
1025          * basis when it encounters pages undergoing async
1026          * I/O.
1027          */
1028         if (object->type == OBJT_VNODE &&
1029             (object->flags & OBJ_MIGHTBEDIRTY) != 0) {
1030                 vp = object->handle;
1031                 VM_OBJECT_WUNLOCK(object);
1032                 (void) vn_start_write(vp, &mp, V_WAIT);
1033                 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1034                 if (syncio && !invalidate && offset == 0 &&
1035                     OFF_TO_IDX(size) == object->size) {
1036                         /*
1037                          * If syncing the whole mapping of the file,
1038                          * it is faster to schedule all the writes in
1039                          * async mode, also allowing the clustering,
1040                          * and then wait for i/o to complete.
1041                          */
1042                         flags = 0;
1043                         fsync_after = TRUE;
1044                 } else {
1045                         flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
1046                         flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0;
1047                         fsync_after = FALSE;
1048                 }
1049                 VM_OBJECT_WLOCK(object);
1050                 res = vm_object_page_clean(object, offset, offset + size,
1051                     flags);
1052                 VM_OBJECT_WUNLOCK(object);
1053                 if (fsync_after)
1054                         error = VOP_FSYNC(vp, MNT_WAIT, curthread);
1055                 VOP_UNLOCK(vp, 0);
1056                 vn_finished_write(mp);
1057                 if (error != 0)
1058                         res = FALSE;
1059                 VM_OBJECT_WLOCK(object);
1060         }
1061         if ((object->type == OBJT_VNODE ||
1062              object->type == OBJT_DEVICE) && invalidate) {
1063                 if (object->type == OBJT_DEVICE)
1064                         /*
1065                          * The option OBJPR_NOTMAPPED must be passed here
1066                          * because vm_object_page_remove() cannot remove
1067                          * unmanaged mappings.
1068                          */
1069                         flags = OBJPR_NOTMAPPED;
1070                 else if (old_msync)
1071                         flags = 0;
1072                 else
1073                         flags = OBJPR_CLEANONLY;
1074                 vm_object_page_remove(object, OFF_TO_IDX(offset),
1075                     OFF_TO_IDX(offset + size + PAGE_MASK), flags);
1076         }
1077         VM_OBJECT_WUNLOCK(object);
1078         return (res);
1079 }
1080
1081 /*
1082  *      vm_object_madvise:
1083  *
1084  *      Implements the madvise function at the object/page level.
1085  *
1086  *      MADV_WILLNEED   (any object)
1087  *
1088  *          Activate the specified pages if they are resident.
1089  *
1090  *      MADV_DONTNEED   (any object)
1091  *
1092  *          Deactivate the specified pages if they are resident.
1093  *
1094  *      MADV_FREE       (OBJT_DEFAULT/OBJT_SWAP objects,
1095  *                       OBJ_ONEMAPPING only)
1096  *
1097  *          Deactivate and clean the specified pages if they are
1098  *          resident.  This permits the process to reuse the pages
1099  *          without faulting or the kernel to reclaim the pages
1100  *          without I/O.
1101  */
1102 void
1103 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end,
1104     int advise)
1105 {
1106         vm_pindex_t tpindex;
1107         vm_object_t backing_object, tobject;
1108         vm_page_t m;
1109
1110         if (object == NULL)
1111                 return;
1112         VM_OBJECT_WLOCK(object);
1113         /*
1114          * Locate and adjust resident pages
1115          */
1116         for (; pindex < end; pindex += 1) {
1117 relookup:
1118                 tobject = object;
1119                 tpindex = pindex;
1120 shadowlookup:
1121                 /*
1122                  * MADV_FREE only operates on OBJT_DEFAULT or OBJT_SWAP pages
1123                  * and those pages must be OBJ_ONEMAPPING.
1124                  */
1125                 if (advise == MADV_FREE) {
1126                         if ((tobject->type != OBJT_DEFAULT &&
1127                              tobject->type != OBJT_SWAP) ||
1128                             (tobject->flags & OBJ_ONEMAPPING) == 0) {
1129                                 goto unlock_tobject;
1130                         }
1131                 } else if ((tobject->flags & OBJ_UNMANAGED) != 0)
1132                         goto unlock_tobject;
1133                 m = vm_page_lookup(tobject, tpindex);
1134                 if (m == NULL && advise == MADV_WILLNEED) {
1135                         /*
1136                          * If the page is cached, reactivate it.
1137                          */
1138                         m = vm_page_alloc(tobject, tpindex, VM_ALLOC_IFCACHED |
1139                             VM_ALLOC_NOBUSY);
1140                 }
1141                 if (m == NULL) {
1142                         /*
1143                          * There may be swap even if there is no backing page
1144                          */
1145                         if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1146                                 swap_pager_freespace(tobject, tpindex, 1);
1147                         /*
1148                          * next object
1149                          */
1150                         backing_object = tobject->backing_object;
1151                         if (backing_object == NULL)
1152                                 goto unlock_tobject;
1153                         VM_OBJECT_WLOCK(backing_object);
1154                         tpindex += OFF_TO_IDX(tobject->backing_object_offset);
1155                         if (tobject != object)
1156                                 VM_OBJECT_WUNLOCK(tobject);
1157                         tobject = backing_object;
1158                         goto shadowlookup;
1159                 } else if (m->valid != VM_PAGE_BITS_ALL)
1160                         goto unlock_tobject;
1161                 /*
1162                  * If the page is not in a normal state, skip it.
1163                  */
1164                 vm_page_lock(m);
1165                 if (m->hold_count != 0 || m->wire_count != 0) {
1166                         vm_page_unlock(m);
1167                         goto unlock_tobject;
1168                 }
1169                 KASSERT((m->flags & PG_FICTITIOUS) == 0,
1170                     ("vm_object_madvise: page %p is fictitious", m));
1171                 KASSERT((m->oflags & VPO_UNMANAGED) == 0,
1172                     ("vm_object_madvise: page %p is not managed", m));
1173                 if (vm_page_busied(m)) {
1174                         if (advise == MADV_WILLNEED) {
1175                                 /*
1176                                  * Reference the page before unlocking and
1177                                  * sleeping so that the page daemon is less
1178                                  * likely to reclaim it.
1179                                  */
1180                                 vm_page_aflag_set(m, PGA_REFERENCED);
1181                         }
1182                         if (object != tobject)
1183                                 VM_OBJECT_WUNLOCK(object);
1184                         VM_OBJECT_WUNLOCK(tobject);
1185                         vm_page_busy_sleep(m, "madvpo");
1186                         VM_OBJECT_WLOCK(object);
1187                         goto relookup;
1188                 }
1189                 if (advise == MADV_WILLNEED) {
1190                         vm_page_activate(m);
1191                 } else {
1192                         vm_page_advise(m, advise);
1193                 }
1194                 vm_page_unlock(m);
1195                 if (advise == MADV_FREE && tobject->type == OBJT_SWAP)
1196                         swap_pager_freespace(tobject, tpindex, 1);
1197 unlock_tobject:
1198                 if (tobject != object)
1199                         VM_OBJECT_WUNLOCK(tobject);
1200         }
1201         VM_OBJECT_WUNLOCK(object);
1202 }
1203
1204 /*
1205  *      vm_object_shadow:
1206  *
1207  *      Create a new object which is backed by the
1208  *      specified existing object range.  The source
1209  *      object reference is deallocated.
1210  *
1211  *      The new object and offset into that object
1212  *      are returned in the source parameters.
1213  */
1214 void
1215 vm_object_shadow(
1216         vm_object_t *object,    /* IN/OUT */
1217         vm_ooffset_t *offset,   /* IN/OUT */
1218         vm_size_t length)
1219 {
1220         vm_object_t source;
1221         vm_object_t result;
1222
1223         source = *object;
1224
1225         /*
1226          * Don't create the new object if the old object isn't shared.
1227          */
1228         if (source != NULL) {
1229                 VM_OBJECT_WLOCK(source);
1230                 if (source->ref_count == 1 &&
1231                     source->handle == NULL &&
1232                     (source->type == OBJT_DEFAULT ||
1233                      source->type == OBJT_SWAP)) {
1234                         VM_OBJECT_WUNLOCK(source);
1235                         return;
1236                 }
1237                 VM_OBJECT_WUNLOCK(source);
1238         }
1239
1240         /*
1241          * Allocate a new object with the given length.
1242          */
1243         result = vm_object_allocate(OBJT_DEFAULT, atop(length));
1244
1245         /*
1246          * The new object shadows the source object, adding a reference to it.
1247          * Our caller changes his reference to point to the new object,
1248          * removing a reference to the source object.  Net result: no change
1249          * of reference count.
1250          *
1251          * Try to optimize the result object's page color when shadowing
1252          * in order to maintain page coloring consistency in the combined
1253          * shadowed object.
1254          */
1255         result->backing_object = source;
1256         /*
1257          * Store the offset into the source object, and fix up the offset into
1258          * the new object.
1259          */
1260         result->backing_object_offset = *offset;
1261         if (source != NULL) {
1262                 VM_OBJECT_WLOCK(source);
1263                 LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
1264                 source->shadow_count++;
1265 #if VM_NRESERVLEVEL > 0
1266                 result->flags |= source->flags & OBJ_COLORED;
1267                 result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) &
1268                     ((1 << (VM_NFREEORDER - 1)) - 1);
1269 #endif
1270                 VM_OBJECT_WUNLOCK(source);
1271         }
1272
1273
1274         /*
1275          * Return the new things
1276          */
1277         *offset = 0;
1278         *object = result;
1279 }
1280
1281 /*
1282  *      vm_object_split:
1283  *
1284  * Split the pages in a map entry into a new object.  This affords
1285  * easier removal of unused pages, and keeps object inheritance from
1286  * being a negative impact on memory usage.
1287  */
1288 void
1289 vm_object_split(vm_map_entry_t entry)
1290 {
1291         vm_page_t m, m_next;
1292         vm_object_t orig_object, new_object, source;
1293         vm_pindex_t idx, offidxstart;
1294         vm_size_t size;
1295
1296         orig_object = entry->object.vm_object;
1297         if (orig_object->type != OBJT_DEFAULT && orig_object->type != OBJT_SWAP)
1298                 return;
1299         if (orig_object->ref_count <= 1)
1300                 return;
1301         VM_OBJECT_WUNLOCK(orig_object);
1302
1303         offidxstart = OFF_TO_IDX(entry->offset);
1304         size = atop(entry->end - entry->start);
1305
1306         /*
1307          * If swap_pager_copy() is later called, it will convert new_object
1308          * into a swap object.
1309          */
1310         new_object = vm_object_allocate(OBJT_DEFAULT, size);
1311
1312         /*
1313          * At this point, the new object is still private, so the order in
1314          * which the original and new objects are locked does not matter.
1315          */
1316         VM_OBJECT_WLOCK(new_object);
1317         VM_OBJECT_WLOCK(orig_object);
1318         source = orig_object->backing_object;
1319         if (source != NULL) {
1320                 VM_OBJECT_WLOCK(source);
1321                 if ((source->flags & OBJ_DEAD) != 0) {
1322                         VM_OBJECT_WUNLOCK(source);
1323                         VM_OBJECT_WUNLOCK(orig_object);
1324                         VM_OBJECT_WUNLOCK(new_object);
1325                         vm_object_deallocate(new_object);
1326                         VM_OBJECT_WLOCK(orig_object);
1327                         return;
1328                 }
1329                 LIST_INSERT_HEAD(&source->shadow_head,
1330                                   new_object, shadow_list);
1331                 source->shadow_count++;
1332                 vm_object_reference_locked(source);     /* for new_object */
1333                 vm_object_clear_flag(source, OBJ_ONEMAPPING);
1334                 VM_OBJECT_WUNLOCK(source);
1335                 new_object->backing_object_offset =
1336                         orig_object->backing_object_offset + entry->offset;
1337                 new_object->backing_object = source;
1338         }
1339         if (orig_object->cred != NULL) {
1340                 new_object->cred = orig_object->cred;
1341                 crhold(orig_object->cred);
1342                 new_object->charge = ptoa(size);
1343                 KASSERT(orig_object->charge >= ptoa(size),
1344                     ("orig_object->charge < 0"));
1345                 orig_object->charge -= ptoa(size);
1346         }
1347 retry:
1348         m = vm_page_find_least(orig_object, offidxstart);
1349         for (; m != NULL && (idx = m->pindex - offidxstart) < size;
1350             m = m_next) {
1351                 m_next = TAILQ_NEXT(m, listq);
1352
1353                 /*
1354                  * We must wait for pending I/O to complete before we can
1355                  * rename the page.
1356                  *
1357                  * We do not have to VM_PROT_NONE the page as mappings should
1358                  * not be changed by this operation.
1359                  */
1360                 if (vm_page_busied(m)) {
1361                         VM_OBJECT_WUNLOCK(new_object);
1362                         vm_page_lock(m);
1363                         VM_OBJECT_WUNLOCK(orig_object);
1364                         vm_page_busy_sleep(m, "spltwt");
1365                         VM_OBJECT_WLOCK(orig_object);
1366                         VM_OBJECT_WLOCK(new_object);
1367                         goto retry;
1368                 }
1369
1370                 /* vm_page_rename() will handle dirty and cache. */
1371                 if (vm_page_rename(m, new_object, idx)) {
1372                         VM_OBJECT_WUNLOCK(new_object);
1373                         VM_OBJECT_WUNLOCK(orig_object);
1374                         VM_WAIT;
1375                         VM_OBJECT_WLOCK(orig_object);
1376                         VM_OBJECT_WLOCK(new_object);
1377                         goto retry;
1378                 }
1379 #if VM_NRESERVLEVEL > 0
1380                 /*
1381                  * If some of the reservation's allocated pages remain with
1382                  * the original object, then transferring the reservation to
1383                  * the new object is neither particularly beneficial nor
1384                  * particularly harmful as compared to leaving the reservation
1385                  * with the original object.  If, however, all of the
1386                  * reservation's allocated pages are transferred to the new
1387                  * object, then transferring the reservation is typically
1388                  * beneficial.  Determining which of these two cases applies
1389                  * would be more costly than unconditionally renaming the
1390                  * reservation.
1391                  */
1392                 vm_reserv_rename(m, new_object, orig_object, offidxstart);
1393 #endif
1394                 if (orig_object->type == OBJT_SWAP)
1395                         vm_page_xbusy(m);
1396         }
1397         if (orig_object->type == OBJT_SWAP) {
1398                 /*
1399                  * swap_pager_copy() can sleep, in which case the orig_object's
1400                  * and new_object's locks are released and reacquired.
1401                  */
1402                 swap_pager_copy(orig_object, new_object, offidxstart, 0);
1403                 TAILQ_FOREACH(m, &new_object->memq, listq)
1404                         vm_page_xunbusy(m);
1405
1406                 /*
1407                  * Transfer any cached pages from orig_object to new_object.
1408                  * If swap_pager_copy() found swapped out pages within the
1409                  * specified range of orig_object, then it changed
1410                  * new_object's type to OBJT_SWAP when it transferred those
1411                  * pages to new_object.  Otherwise, new_object's type
1412                  * should still be OBJT_DEFAULT and orig_object should not
1413                  * contain any cached pages within the specified range.
1414                  */
1415                 if (__predict_false(!vm_object_cache_is_empty(orig_object)))
1416                         vm_page_cache_transfer(orig_object, offidxstart,
1417                             new_object);
1418         }
1419         VM_OBJECT_WUNLOCK(orig_object);
1420         VM_OBJECT_WUNLOCK(new_object);
1421         entry->object.vm_object = new_object;
1422         entry->offset = 0LL;
1423         vm_object_deallocate(orig_object);
1424         VM_OBJECT_WLOCK(new_object);
1425 }
1426
1427 #define OBSC_TEST_ALL_SHADOWED  0x0001
1428 #define OBSC_COLLAPSE_NOWAIT    0x0002
1429 #define OBSC_COLLAPSE_WAIT      0x0004
1430
1431 static vm_page_t
1432 vm_object_backing_scan_wait(vm_object_t object, vm_page_t p, vm_page_t next,
1433     int op)
1434 {
1435         vm_object_t backing_object;
1436
1437         VM_OBJECT_ASSERT_WLOCKED(object);
1438         backing_object = object->backing_object;
1439         VM_OBJECT_ASSERT_WLOCKED(backing_object);
1440
1441         KASSERT(p == NULL || vm_page_busied(p), ("unbusy page %p", p));
1442         KASSERT(p == NULL || p->object == object || p->object == backing_object,
1443             ("invalid ownership %p %p %p", p, object, backing_object));
1444         if ((op & OBSC_COLLAPSE_NOWAIT) != 0)
1445                 return (next);
1446         if (p != NULL)
1447                 vm_page_lock(p);
1448         VM_OBJECT_WUNLOCK(object);
1449         VM_OBJECT_WUNLOCK(backing_object);
1450         if (p == NULL)
1451                 VM_WAIT;
1452         else
1453                 vm_page_busy_sleep(p, "vmocol");
1454         VM_OBJECT_WLOCK(object);
1455         VM_OBJECT_WLOCK(backing_object);
1456         return (TAILQ_FIRST(&backing_object->memq));
1457 }
1458
1459 static bool
1460 vm_object_backing_scan(vm_object_t object, int op)
1461 {
1462         vm_object_t backing_object;
1463         vm_page_t next, p, pp;
1464         vm_pindex_t backing_offset_index, new_pindex;
1465
1466         VM_OBJECT_ASSERT_WLOCKED(object);
1467         VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
1468
1469         backing_object = object->backing_object;
1470         backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1471
1472         /*
1473          * Initial conditions
1474          */
1475         if (op & OBSC_TEST_ALL_SHADOWED) {
1476                 /*
1477                  * We do not want to have to test for the existence of cache
1478                  * or swap pages in the backing object.  XXX but with the
1479                  * new swapper this would be pretty easy to do.
1480                  *
1481                  * XXX what about anonymous MAP_SHARED memory that hasn't
1482                  * been ZFOD faulted yet?  If we do not test for this, the
1483                  * shadow test may succeed! XXX
1484                  */
1485                 if (backing_object->type != OBJT_DEFAULT) {
1486                         return (false);
1487                 }
1488         }
1489         if (op & OBSC_COLLAPSE_WAIT) {
1490                 vm_object_set_flag(backing_object, OBJ_DEAD);
1491         }
1492
1493         /*
1494          * Our scan
1495          */
1496         p = TAILQ_FIRST(&backing_object->memq);
1497         while (p) {
1498                 next = TAILQ_NEXT(p, listq);
1499                 new_pindex = p->pindex - backing_offset_index;
1500                 if (op & OBSC_TEST_ALL_SHADOWED) {
1501                         /*
1502                          * Ignore pages outside the parent object's range
1503                          * and outside the parent object's mapping of the
1504                          * backing object.
1505                          *
1506                          * Note that we do not busy the backing object's
1507                          * page.
1508                          */
1509                         if (p->pindex < backing_offset_index ||
1510                             new_pindex >= object->size) {
1511                                 p = next;
1512                                 continue;
1513                         }
1514
1515                         /*
1516                          * See if the parent has the page or if the parent's
1517                          * object pager has the page.  If the parent has the
1518                          * page but the page is not valid, the parent's
1519                          * object pager must have the page.
1520                          *
1521                          * If this fails, the parent does not completely shadow
1522                          * the object and we might as well give up now.
1523                          */
1524
1525                         pp = vm_page_lookup(object, new_pindex);
1526                         if ((pp == NULL || pp->valid == 0) &&
1527                             !vm_pager_has_page(object, new_pindex, NULL, NULL))
1528                                 return (false);
1529                 }
1530
1531                 /*
1532                  * Check for busy page
1533                  */
1534                 if (op & (OBSC_COLLAPSE_WAIT | OBSC_COLLAPSE_NOWAIT)) {
1535                         if (vm_page_busied(p)) {
1536                                 p = vm_object_backing_scan_wait(object, p,
1537                                     next, op);
1538                                 continue;
1539                         }
1540
1541                         KASSERT(p->object == backing_object,
1542                             ("vm_object_backing_scan: object mismatch"));
1543
1544                         if (p->pindex < backing_offset_index ||
1545                             new_pindex >= object->size) {
1546                                 if (backing_object->type == OBJT_SWAP)
1547                                         swap_pager_freespace(backing_object,
1548                                             p->pindex, 1);
1549
1550                                 /*
1551                                  * Page is out of the parent object's range, we
1552                                  * can simply destroy it.
1553                                  */
1554                                 vm_page_lock(p);
1555                                 KASSERT(!pmap_page_is_mapped(p),
1556                                     ("freeing mapped page %p", p));
1557                                 if (p->wire_count == 0)
1558                                         vm_page_free(p);
1559                                 else
1560                                         vm_page_remove(p);
1561                                 vm_page_unlock(p);
1562                                 p = next;
1563                                 continue;
1564                         }
1565
1566                         pp = vm_page_lookup(object, new_pindex);
1567                         if (pp != NULL && vm_page_busied(pp)) {
1568                                 /*
1569                                  * The page in the parent is busy and
1570                                  * possibly not (yet) valid.  Until
1571                                  * its state is finalized by the busy
1572                                  * bit owner, we can't tell whether it
1573                                  * shadows the original page.
1574                                  * Therefore, we must either skip it
1575                                  * and the original (backing_object)
1576                                  * page or wait for its state to be
1577                                  * finalized.
1578                                  *
1579                                  * This is due to a race with vm_fault()
1580                                  * where we must unbusy the original
1581                                  * (backing_obj) page before we can
1582                                  * (re)lock the parent.  Hence we can
1583                                  * get here.
1584                                  */
1585                                 p = vm_object_backing_scan_wait(object, pp,
1586                                     next, op);
1587                                 continue;
1588                         }
1589
1590                         KASSERT(pp == NULL || pp->valid != 0,
1591                             ("unbusy invalid page %p", pp));
1592
1593                         if (pp != NULL || vm_pager_has_page(object,
1594                             new_pindex, NULL, NULL)) {
1595                                 /*
1596                                  * The page already exists in the
1597                                  * parent OR swap exists for this
1598                                  * location in the parent.  Leave the
1599                                  * parent's page alone.  Destroy the
1600                                  * original page from the backing
1601                                  * object.
1602                                  */
1603                                 if (backing_object->type == OBJT_SWAP)
1604                                         swap_pager_freespace(backing_object,
1605                                             p->pindex, 1);
1606                                 vm_page_lock(p);
1607                                 KASSERT(!pmap_page_is_mapped(p),
1608                                     ("freeing mapped page %p", p));
1609                                 if (p->wire_count == 0)
1610                                         vm_page_free(p);
1611                                 else
1612                                         vm_page_remove(p);
1613                                 vm_page_unlock(p);
1614                                 p = next;
1615                                 continue;
1616                         }
1617
1618                         /*
1619                          * Page does not exist in parent, rename the
1620                          * page from the backing object to the main object.
1621                          *
1622                          * If the page was mapped to a process, it can remain
1623                          * mapped through the rename.
1624                          * vm_page_rename() will handle dirty and cache.
1625                          */
1626                         if (vm_page_rename(p, object, new_pindex)) {
1627                                 p = vm_object_backing_scan_wait(object, NULL,
1628                                     next, op);
1629                                 continue;
1630                         }
1631
1632                         /* Use the old pindex to free the right page. */
1633                         if (backing_object->type == OBJT_SWAP)
1634                                 swap_pager_freespace(backing_object,
1635                                     new_pindex + backing_offset_index, 1);
1636
1637 #if VM_NRESERVLEVEL > 0
1638                         /*
1639                          * Rename the reservation.
1640                          */
1641                         vm_reserv_rename(p, object, backing_object,
1642                             backing_offset_index);
1643 #endif
1644                 }
1645                 p = next;
1646         }
1647         return (true);
1648 }
1649
1650
1651 /*
1652  * this version of collapse allows the operation to occur earlier and
1653  * when paging_in_progress is true for an object...  This is not a complete
1654  * operation, but should plug 99.9% of the rest of the leaks.
1655  */
1656 static void
1657 vm_object_qcollapse(vm_object_t object)
1658 {
1659         vm_object_t backing_object = object->backing_object;
1660
1661         VM_OBJECT_ASSERT_WLOCKED(object);
1662         VM_OBJECT_ASSERT_WLOCKED(backing_object);
1663
1664         if (backing_object->ref_count != 1)
1665                 return;
1666
1667         vm_object_backing_scan(object, OBSC_COLLAPSE_NOWAIT);
1668 }
1669
1670 /*
1671  *      vm_object_collapse:
1672  *
1673  *      Collapse an object with the object backing it.
1674  *      Pages in the backing object are moved into the
1675  *      parent, and the backing object is deallocated.
1676  */
1677 void
1678 vm_object_collapse(vm_object_t object)
1679 {
1680         VM_OBJECT_ASSERT_WLOCKED(object);
1681
1682         while (TRUE) {
1683                 vm_object_t backing_object;
1684
1685                 /*
1686                  * Verify that the conditions are right for collapse:
1687                  *
1688                  * The object exists and the backing object exists.
1689                  */
1690                 if ((backing_object = object->backing_object) == NULL)
1691                         break;
1692
1693                 /*
1694                  * we check the backing object first, because it is most likely
1695                  * not collapsable.
1696                  */
1697                 VM_OBJECT_WLOCK(backing_object);
1698                 if (backing_object->handle != NULL ||
1699                     (backing_object->type != OBJT_DEFAULT &&
1700                      backing_object->type != OBJT_SWAP) ||
1701                     (backing_object->flags & OBJ_DEAD) ||
1702                     object->handle != NULL ||
1703                     (object->type != OBJT_DEFAULT &&
1704                      object->type != OBJT_SWAP) ||
1705                     (object->flags & OBJ_DEAD)) {
1706                         VM_OBJECT_WUNLOCK(backing_object);
1707                         break;
1708                 }
1709
1710                 if (
1711                     object->paging_in_progress != 0 ||
1712                     backing_object->paging_in_progress != 0
1713                 ) {
1714                         vm_object_qcollapse(object);
1715                         VM_OBJECT_WUNLOCK(backing_object);
1716                         break;
1717                 }
1718                 /*
1719                  * We know that we can either collapse the backing object (if
1720                  * the parent is the only reference to it) or (perhaps) have
1721                  * the parent bypass the object if the parent happens to shadow
1722                  * all the resident pages in the entire backing object.
1723                  *
1724                  * This is ignoring pager-backed pages such as swap pages.
1725                  * vm_object_backing_scan fails the shadowing test in this
1726                  * case.
1727                  */
1728                 if (backing_object->ref_count == 1) {
1729                         vm_object_pip_add(object, 1);
1730                         vm_object_pip_add(backing_object, 1);
1731
1732                         /*
1733                          * If there is exactly one reference to the backing
1734                          * object, we can collapse it into the parent.
1735                          */
1736                         vm_object_backing_scan(object, OBSC_COLLAPSE_WAIT);
1737
1738 #if VM_NRESERVLEVEL > 0
1739                         /*
1740                          * Break any reservations from backing_object.
1741                          */
1742                         if (__predict_false(!LIST_EMPTY(&backing_object->rvq)))
1743                                 vm_reserv_break_all(backing_object);
1744 #endif
1745
1746                         /*
1747                          * Move the pager from backing_object to object.
1748                          */
1749                         if (backing_object->type == OBJT_SWAP) {
1750                                 /*
1751                                  * swap_pager_copy() can sleep, in which case
1752                                  * the backing_object's and object's locks are
1753                                  * released and reacquired.
1754                                  * Since swap_pager_copy() is being asked to
1755                                  * destroy the source, it will change the
1756                                  * backing_object's type to OBJT_DEFAULT.
1757                                  */
1758                                 swap_pager_copy(
1759                                     backing_object,
1760                                     object,
1761                                     OFF_TO_IDX(object->backing_object_offset), TRUE);
1762
1763                                 /*
1764                                  * Free any cached pages from backing_object.
1765                                  */
1766                                 if (__predict_false(
1767                                     !vm_object_cache_is_empty(backing_object)))
1768                                         vm_page_cache_free(backing_object, 0, 0);
1769                         }
1770                         /*
1771                          * Object now shadows whatever backing_object did.
1772                          * Note that the reference to
1773                          * backing_object->backing_object moves from within
1774                          * backing_object to within object.
1775                          */
1776                         LIST_REMOVE(object, shadow_list);
1777                         backing_object->shadow_count--;
1778                         if (backing_object->backing_object) {
1779                                 VM_OBJECT_WLOCK(backing_object->backing_object);
1780                                 LIST_REMOVE(backing_object, shadow_list);
1781                                 LIST_INSERT_HEAD(
1782                                     &backing_object->backing_object->shadow_head,
1783                                     object, shadow_list);
1784                                 /*
1785                                  * The shadow_count has not changed.
1786                                  */
1787                                 VM_OBJECT_WUNLOCK(backing_object->backing_object);
1788                         }
1789                         object->backing_object = backing_object->backing_object;
1790                         object->backing_object_offset +=
1791                             backing_object->backing_object_offset;
1792
1793                         /*
1794                          * Discard backing_object.
1795                          *
1796                          * Since the backing object has no pages, no pager left,
1797                          * and no object references within it, all that is
1798                          * necessary is to dispose of it.
1799                          */
1800                         KASSERT(backing_object->ref_count == 1, (
1801 "backing_object %p was somehow re-referenced during collapse!",
1802                             backing_object));
1803                         vm_object_pip_wakeup(backing_object);
1804                         backing_object->type = OBJT_DEAD;
1805                         backing_object->ref_count = 0;
1806                         VM_OBJECT_WUNLOCK(backing_object);
1807                         vm_object_destroy(backing_object);
1808
1809                         vm_object_pip_wakeup(object);
1810                         object_collapses++;
1811                 } else {
1812                         vm_object_t new_backing_object;
1813
1814                         /*
1815                          * If we do not entirely shadow the backing object,
1816                          * there is nothing we can do so we give up.
1817                          */
1818                         if (object->resident_page_count != object->size &&
1819                             !vm_object_backing_scan(object,
1820                             OBSC_TEST_ALL_SHADOWED)) {
1821                                 VM_OBJECT_WUNLOCK(backing_object);
1822                                 break;
1823                         }
1824
1825                         /*
1826                          * Make the parent shadow the next object in the
1827                          * chain.  Deallocating backing_object will not remove
1828                          * it, since its reference count is at least 2.
1829                          */
1830                         LIST_REMOVE(object, shadow_list);
1831                         backing_object->shadow_count--;
1832
1833                         new_backing_object = backing_object->backing_object;
1834                         if ((object->backing_object = new_backing_object) != NULL) {
1835                                 VM_OBJECT_WLOCK(new_backing_object);
1836                                 LIST_INSERT_HEAD(
1837                                     &new_backing_object->shadow_head,
1838                                     object,
1839                                     shadow_list
1840                                 );
1841                                 new_backing_object->shadow_count++;
1842                                 vm_object_reference_locked(new_backing_object);
1843                                 VM_OBJECT_WUNLOCK(new_backing_object);
1844                                 object->backing_object_offset +=
1845                                         backing_object->backing_object_offset;
1846                         }
1847
1848                         /*
1849                          * Drop the reference count on backing_object. Since
1850                          * its ref_count was at least 2, it will not vanish.
1851                          */
1852                         backing_object->ref_count--;
1853                         VM_OBJECT_WUNLOCK(backing_object);
1854                         object_bypasses++;
1855                 }
1856
1857                 /*
1858                  * Try again with this object's new backing object.
1859                  */
1860         }
1861 }
1862
1863 /*
1864  *      vm_object_page_remove:
1865  *
1866  *      For the given object, either frees or invalidates each of the
1867  *      specified pages.  In general, a page is freed.  However, if a page is
1868  *      wired for any reason other than the existence of a managed, wired
1869  *      mapping, then it may be invalidated but not removed from the object.
1870  *      Pages are specified by the given range ["start", "end") and the option
1871  *      OBJPR_CLEANONLY.  As a special case, if "end" is zero, then the range
1872  *      extends from "start" to the end of the object.  If the option
1873  *      OBJPR_CLEANONLY is specified, then only the non-dirty pages within the
1874  *      specified range are affected.  If the option OBJPR_NOTMAPPED is
1875  *      specified, then the pages within the specified range must have no
1876  *      mappings.  Otherwise, if this option is not specified, any mappings to
1877  *      the specified pages are removed before the pages are freed or
1878  *      invalidated.
1879  *
1880  *      In general, this operation should only be performed on objects that
1881  *      contain managed pages.  There are, however, two exceptions.  First, it
1882  *      is performed on the kernel and kmem objects by vm_map_entry_delete().
1883  *      Second, it is used by msync(..., MS_INVALIDATE) to invalidate device-
1884  *      backed pages.  In both of these cases, the option OBJPR_CLEANONLY must
1885  *      not be specified and the option OBJPR_NOTMAPPED must be specified.
1886  *
1887  *      The object must be locked.
1888  */
1889 void
1890 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
1891     int options)
1892 {
1893         vm_page_t p, next;
1894
1895         VM_OBJECT_ASSERT_WLOCKED(object);
1896         KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
1897             (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
1898             ("vm_object_page_remove: illegal options for object %p", object));
1899         if (object->resident_page_count == 0)
1900                 goto skipmemq;
1901         vm_object_pip_add(object, 1);
1902 again:
1903         p = vm_page_find_least(object, start);
1904
1905         /*
1906          * Here, the variable "p" is either (1) the page with the least pindex
1907          * greater than or equal to the parameter "start" or (2) NULL.
1908          */
1909         for (; p != NULL && (p->pindex < end || end == 0); p = next) {
1910                 next = TAILQ_NEXT(p, listq);
1911
1912                 /*
1913                  * If the page is wired for any reason besides the existence
1914                  * of managed, wired mappings, then it cannot be freed.  For
1915                  * example, fictitious pages, which represent device memory,
1916                  * are inherently wired and cannot be freed.  They can,
1917                  * however, be invalidated if the option OBJPR_CLEANONLY is
1918                  * not specified.
1919                  */
1920                 vm_page_lock(p);
1921                 if (vm_page_xbusied(p)) {
1922                         VM_OBJECT_WUNLOCK(object);
1923                         vm_page_busy_sleep(p, "vmopax");
1924                         VM_OBJECT_WLOCK(object);
1925                         goto again;
1926                 }
1927                 if (p->wire_count != 0) {
1928                         if ((options & OBJPR_NOTMAPPED) == 0)
1929                                 pmap_remove_all(p);
1930                         if ((options & OBJPR_CLEANONLY) == 0) {
1931                                 p->valid = 0;
1932                                 vm_page_undirty(p);
1933                         }
1934                         goto next;
1935                 }
1936                 if (vm_page_busied(p)) {
1937                         VM_OBJECT_WUNLOCK(object);
1938                         vm_page_busy_sleep(p, "vmopar");
1939                         VM_OBJECT_WLOCK(object);
1940                         goto again;
1941                 }
1942                 KASSERT((p->flags & PG_FICTITIOUS) == 0,
1943                     ("vm_object_page_remove: page %p is fictitious", p));
1944                 if ((options & OBJPR_CLEANONLY) != 0 && p->valid != 0) {
1945                         if ((options & OBJPR_NOTMAPPED) == 0)
1946                                 pmap_remove_write(p);
1947                         if (p->dirty)
1948                                 goto next;
1949                 }
1950                 if ((options & OBJPR_NOTMAPPED) == 0)
1951                         pmap_remove_all(p);
1952                 vm_page_free(p);
1953 next:
1954                 vm_page_unlock(p);
1955         }
1956         vm_object_pip_wakeup(object);
1957 skipmemq:
1958         if (__predict_false(!vm_object_cache_is_empty(object)))
1959                 vm_page_cache_free(object, start, end);
1960 }
1961
1962 /*
1963  *      vm_object_page_cache:
1964  *
1965  *      For the given object, attempt to move the specified clean
1966  *      pages to the cache queue.  If a page is wired for any reason,
1967  *      then it will not be changed.  Pages are specified by the given
1968  *      range ["start", "end").  As a special case, if "end" is zero,
1969  *      then the range extends from "start" to the end of the object.
1970  *      Any mappings to the specified pages are removed before the
1971  *      pages are moved to the cache queue.
1972  *
1973  *      This operation should only be performed on objects that
1974  *      contain non-fictitious, managed pages.
1975  *
1976  *      The object must be locked.
1977  */
1978 void
1979 vm_object_page_cache(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
1980 {
1981         struct mtx *mtx, *new_mtx;
1982         vm_page_t p, next;
1983
1984         VM_OBJECT_ASSERT_WLOCKED(object);
1985         KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0,
1986             ("vm_object_page_cache: illegal object %p", object));
1987         if (object->resident_page_count == 0)
1988                 return;
1989         p = vm_page_find_least(object, start);
1990
1991         /*
1992          * Here, the variable "p" is either (1) the page with the least pindex
1993          * greater than or equal to the parameter "start" or (2) NULL.
1994          */
1995         mtx = NULL;
1996         for (; p != NULL && (p->pindex < end || end == 0); p = next) {
1997                 next = TAILQ_NEXT(p, listq);
1998
1999                 /*
2000                  * Avoid releasing and reacquiring the same page lock.
2001                  */
2002                 new_mtx = vm_page_lockptr(p);
2003                 if (mtx != new_mtx) {
2004                         if (mtx != NULL)
2005                                 mtx_unlock(mtx);
2006                         mtx = new_mtx;
2007                         mtx_lock(mtx);
2008                 }
2009                 vm_page_try_to_cache(p);
2010         }
2011         if (mtx != NULL)
2012                 mtx_unlock(mtx);
2013 }
2014
2015 /*
2016  *      Populate the specified range of the object with valid pages.  Returns
2017  *      TRUE if the range is successfully populated and FALSE otherwise.
2018  *
2019  *      Note: This function should be optimized to pass a larger array of
2020  *      pages to vm_pager_get_pages() before it is applied to a non-
2021  *      OBJT_DEVICE object.
2022  *
2023  *      The object must be locked.
2024  */
2025 boolean_t
2026 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
2027 {
2028         vm_page_t m, ma[1];
2029         vm_pindex_t pindex;
2030         int rv;
2031
2032         VM_OBJECT_ASSERT_WLOCKED(object);
2033         for (pindex = start; pindex < end; pindex++) {
2034                 m = vm_page_grab(object, pindex, VM_ALLOC_NORMAL);
2035                 if (m->valid != VM_PAGE_BITS_ALL) {
2036                         ma[0] = m;
2037                         rv = vm_pager_get_pages(object, ma, 1, 0);
2038                         m = vm_page_lookup(object, pindex);
2039                         if (m == NULL)
2040                                 break;
2041                         if (rv != VM_PAGER_OK) {
2042                                 vm_page_lock(m);
2043                                 vm_page_free(m);
2044                                 vm_page_unlock(m);
2045                                 break;
2046                         }
2047                 }
2048                 /*
2049                  * Keep "m" busy because a subsequent iteration may unlock
2050                  * the object.
2051                  */
2052         }
2053         if (pindex > start) {
2054                 m = vm_page_lookup(object, start);
2055                 while (m != NULL && m->pindex < pindex) {
2056                         vm_page_xunbusy(m);
2057                         m = TAILQ_NEXT(m, listq);
2058                 }
2059         }
2060         return (pindex == end);
2061 }
2062
2063 /*
2064  *      Routine:        vm_object_coalesce
2065  *      Function:       Coalesces two objects backing up adjoining
2066  *                      regions of memory into a single object.
2067  *
2068  *      returns TRUE if objects were combined.
2069  *
2070  *      NOTE:   Only works at the moment if the second object is NULL -
2071  *              if it's not, which object do we lock first?
2072  *
2073  *      Parameters:
2074  *              prev_object     First object to coalesce
2075  *              prev_offset     Offset into prev_object
2076  *              prev_size       Size of reference to prev_object
2077  *              next_size       Size of reference to the second object
2078  *              reserved        Indicator that extension region has
2079  *                              swap accounted for
2080  *
2081  *      Conditions:
2082  *      The object must *not* be locked.
2083  */
2084 boolean_t
2085 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset,
2086     vm_size_t prev_size, vm_size_t next_size, boolean_t reserved)
2087 {
2088         vm_pindex_t next_pindex;
2089
2090         if (prev_object == NULL)
2091                 return (TRUE);
2092         VM_OBJECT_WLOCK(prev_object);
2093         if ((prev_object->type != OBJT_DEFAULT &&
2094             prev_object->type != OBJT_SWAP) ||
2095             (prev_object->flags & OBJ_TMPFS_NODE) != 0) {
2096                 VM_OBJECT_WUNLOCK(prev_object);
2097                 return (FALSE);
2098         }
2099
2100         /*
2101          * Try to collapse the object first
2102          */
2103         vm_object_collapse(prev_object);
2104
2105         /*
2106          * Can't coalesce if: . more than one reference . paged out . shadows
2107          * another object . has a copy elsewhere (any of which mean that the
2108          * pages not mapped to prev_entry may be in use anyway)
2109          */
2110         if (prev_object->backing_object != NULL) {
2111                 VM_OBJECT_WUNLOCK(prev_object);
2112                 return (FALSE);
2113         }
2114
2115         prev_size >>= PAGE_SHIFT;
2116         next_size >>= PAGE_SHIFT;
2117         next_pindex = OFF_TO_IDX(prev_offset) + prev_size;
2118
2119         if ((prev_object->ref_count > 1) &&
2120             (prev_object->size != next_pindex)) {
2121                 VM_OBJECT_WUNLOCK(prev_object);
2122                 return (FALSE);
2123         }
2124
2125         /*
2126          * Account for the charge.
2127          */
2128         if (prev_object->cred != NULL) {
2129
2130                 /*
2131                  * If prev_object was charged, then this mapping,
2132                  * althought not charged now, may become writable
2133                  * later. Non-NULL cred in the object would prevent
2134                  * swap reservation during enabling of the write
2135                  * access, so reserve swap now. Failed reservation
2136                  * cause allocation of the separate object for the map
2137                  * entry, and swap reservation for this entry is
2138                  * managed in appropriate time.
2139                  */
2140                 if (!reserved && !swap_reserve_by_cred(ptoa(next_size),
2141                     prev_object->cred)) {
2142                         VM_OBJECT_WUNLOCK(prev_object);
2143                         return (FALSE);
2144                 }
2145                 prev_object->charge += ptoa(next_size);
2146         }
2147
2148         /*
2149          * Remove any pages that may still be in the object from a previous
2150          * deallocation.
2151          */
2152         if (next_pindex < prev_object->size) {
2153                 vm_object_page_remove(prev_object, next_pindex, next_pindex +
2154                     next_size, 0);
2155                 if (prev_object->type == OBJT_SWAP)
2156                         swap_pager_freespace(prev_object,
2157                                              next_pindex, next_size);
2158 #if 0
2159                 if (prev_object->cred != NULL) {
2160                         KASSERT(prev_object->charge >=
2161                             ptoa(prev_object->size - next_pindex),
2162                             ("object %p overcharged 1 %jx %jx", prev_object,
2163                                 (uintmax_t)next_pindex, (uintmax_t)next_size));
2164                         prev_object->charge -= ptoa(prev_object->size -
2165                             next_pindex);
2166                 }
2167 #endif
2168         }
2169
2170         /*
2171          * Extend the object if necessary.
2172          */
2173         if (next_pindex + next_size > prev_object->size)
2174                 prev_object->size = next_pindex + next_size;
2175
2176         VM_OBJECT_WUNLOCK(prev_object);
2177         return (TRUE);
2178 }
2179
2180 void
2181 vm_object_set_writeable_dirty(vm_object_t object)
2182 {
2183
2184         VM_OBJECT_ASSERT_WLOCKED(object);
2185         if (object->type != OBJT_VNODE) {
2186                 if ((object->flags & OBJ_TMPFS_NODE) != 0) {
2187                         KASSERT(object->type == OBJT_SWAP, ("non-swap tmpfs"));
2188                         vm_object_set_flag(object, OBJ_TMPFS_DIRTY);
2189                 }
2190                 return;
2191         }
2192         object->generation++;
2193         if ((object->flags & OBJ_MIGHTBEDIRTY) != 0)
2194                 return;
2195         vm_object_set_flag(object, OBJ_MIGHTBEDIRTY);
2196 }
2197
2198 /*
2199  *      vm_object_unwire:
2200  *
2201  *      For each page offset within the specified range of the given object,
2202  *      find the highest-level page in the shadow chain and unwire it.  A page
2203  *      must exist at every page offset, and the highest-level page must be
2204  *      wired.
2205  */
2206 void
2207 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length,
2208     uint8_t queue)
2209 {
2210         vm_object_t tobject;
2211         vm_page_t m, tm;
2212         vm_pindex_t end_pindex, pindex, tpindex;
2213         int depth, locked_depth;
2214
2215         KASSERT((offset & PAGE_MASK) == 0,
2216             ("vm_object_unwire: offset is not page aligned"));
2217         KASSERT((length & PAGE_MASK) == 0,
2218             ("vm_object_unwire: length is not a multiple of PAGE_SIZE"));
2219         /* The wired count of a fictitious page never changes. */
2220         if ((object->flags & OBJ_FICTITIOUS) != 0)
2221                 return;
2222         pindex = OFF_TO_IDX(offset);
2223         end_pindex = pindex + atop(length);
2224         locked_depth = 1;
2225         VM_OBJECT_RLOCK(object);
2226         m = vm_page_find_least(object, pindex);
2227         while (pindex < end_pindex) {
2228                 if (m == NULL || pindex < m->pindex) {
2229                         /*
2230                          * The first object in the shadow chain doesn't
2231                          * contain a page at the current index.  Therefore,
2232                          * the page must exist in a backing object.
2233                          */
2234                         tobject = object;
2235                         tpindex = pindex;
2236                         depth = 0;
2237                         do {
2238                                 tpindex +=
2239                                     OFF_TO_IDX(tobject->backing_object_offset);
2240                                 tobject = tobject->backing_object;
2241                                 KASSERT(tobject != NULL,
2242                                     ("vm_object_unwire: missing page"));
2243                                 if ((tobject->flags & OBJ_FICTITIOUS) != 0)
2244                                         goto next_page;
2245                                 depth++;
2246                                 if (depth == locked_depth) {
2247                                         locked_depth++;
2248                                         VM_OBJECT_RLOCK(tobject);
2249                                 }
2250                         } while ((tm = vm_page_lookup(tobject, tpindex)) ==
2251                             NULL);
2252                 } else {
2253                         tm = m;
2254                         m = TAILQ_NEXT(m, listq);
2255                 }
2256                 vm_page_lock(tm);
2257                 vm_page_unwire(tm, queue);
2258                 vm_page_unlock(tm);
2259 next_page:
2260                 pindex++;
2261         }
2262         /* Release the accumulated object locks. */
2263         for (depth = 0; depth < locked_depth; depth++) {
2264                 tobject = object->backing_object;
2265                 VM_OBJECT_RUNLOCK(object);
2266                 object = tobject;
2267         }
2268 }
2269
2270 struct vnode *
2271 vm_object_vnode(vm_object_t object)
2272 {
2273
2274         VM_OBJECT_ASSERT_LOCKED(object);
2275         if (object->type == OBJT_VNODE)
2276                 return (object->handle);
2277         if (object->type == OBJT_SWAP && (object->flags & OBJ_TMPFS) != 0)
2278                 return (object->un_pager.swp.swp_tmpfs);
2279         return (NULL);
2280 }
2281
2282 static int
2283 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS)
2284 {
2285         struct kinfo_vmobject kvo;
2286         char *fullpath, *freepath;
2287         struct vnode *vp;
2288         struct vattr va;
2289         vm_object_t obj;
2290         vm_page_t m;
2291         int count, error;
2292
2293         if (req->oldptr == NULL) {
2294                 /*
2295                  * If an old buffer has not been provided, generate an
2296                  * estimate of the space needed for a subsequent call.
2297                  */
2298                 mtx_lock(&vm_object_list_mtx);
2299                 count = 0;
2300                 TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2301                         if (obj->type == OBJT_DEAD)
2302                                 continue;
2303                         count++;
2304                 }
2305                 mtx_unlock(&vm_object_list_mtx);
2306                 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) *
2307                     count * 11 / 10));
2308         }
2309
2310         error = 0;
2311
2312         /*
2313          * VM objects are type stable and are never removed from the
2314          * list once added.  This allows us to safely read obj->object_list
2315          * after reacquiring the VM object lock.
2316          */
2317         mtx_lock(&vm_object_list_mtx);
2318         TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2319                 if (obj->type == OBJT_DEAD)
2320                         continue;
2321                 VM_OBJECT_RLOCK(obj);
2322                 if (obj->type == OBJT_DEAD) {
2323                         VM_OBJECT_RUNLOCK(obj);
2324                         continue;
2325                 }
2326                 mtx_unlock(&vm_object_list_mtx);
2327                 kvo.kvo_size = ptoa(obj->size);
2328                 kvo.kvo_resident = obj->resident_page_count;
2329                 kvo.kvo_ref_count = obj->ref_count;
2330                 kvo.kvo_shadow_count = obj->shadow_count;
2331                 kvo.kvo_memattr = obj->memattr;
2332                 kvo.kvo_active = 0;
2333                 kvo.kvo_inactive = 0;
2334                 TAILQ_FOREACH(m, &obj->memq, listq) {
2335                         /*
2336                          * A page may belong to the object but be
2337                          * dequeued and set to PQ_NONE while the
2338                          * object lock is not held.  This makes the
2339                          * reads of m->queue below racy, and we do not
2340                          * count pages set to PQ_NONE.  However, this
2341                          * sysctl is only meant to give an
2342                          * approximation of the system anyway.
2343                          */
2344                         if (m->queue == PQ_ACTIVE)
2345                                 kvo.kvo_active++;
2346                         else if (m->queue == PQ_INACTIVE)
2347                                 kvo.kvo_inactive++;
2348                 }
2349
2350                 kvo.kvo_vn_fileid = 0;
2351                 kvo.kvo_vn_fsid = 0;
2352                 freepath = NULL;
2353                 fullpath = "";
2354                 vp = NULL;
2355                 switch (obj->type) {
2356                 case OBJT_DEFAULT:
2357                         kvo.kvo_type = KVME_TYPE_DEFAULT;
2358                         break;
2359                 case OBJT_VNODE:
2360                         kvo.kvo_type = KVME_TYPE_VNODE;
2361                         vp = obj->handle;
2362                         vref(vp);
2363                         break;
2364                 case OBJT_SWAP:
2365                         kvo.kvo_type = KVME_TYPE_SWAP;
2366                         break;
2367                 case OBJT_DEVICE:
2368                         kvo.kvo_type = KVME_TYPE_DEVICE;
2369                         break;
2370                 case OBJT_PHYS:
2371                         kvo.kvo_type = KVME_TYPE_PHYS;
2372                         break;
2373                 case OBJT_DEAD:
2374                         kvo.kvo_type = KVME_TYPE_DEAD;
2375                         break;
2376                 case OBJT_SG:
2377                         kvo.kvo_type = KVME_TYPE_SG;
2378                         break;
2379                 case OBJT_MGTDEVICE:
2380                         kvo.kvo_type = KVME_TYPE_MGTDEVICE;
2381                         break;
2382                 default:
2383                         kvo.kvo_type = KVME_TYPE_UNKNOWN;
2384                         break;
2385                 }
2386                 VM_OBJECT_RUNLOCK(obj);
2387                 if (vp != NULL) {
2388                         vn_fullpath(curthread, vp, &fullpath, &freepath);
2389                         vn_lock(vp, LK_SHARED | LK_RETRY);
2390                         if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) {
2391                                 kvo.kvo_vn_fileid = va.va_fileid;
2392                                 kvo.kvo_vn_fsid = va.va_fsid;
2393                         }
2394                         vput(vp);
2395                 }
2396
2397                 strlcpy(kvo.kvo_path, fullpath, sizeof(kvo.kvo_path));
2398                 if (freepath != NULL)
2399                         free(freepath, M_TEMP);
2400
2401                 /* Pack record size down */
2402                 kvo.kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path) +
2403                     strlen(kvo.kvo_path) + 1;
2404                 kvo.kvo_structsize = roundup(kvo.kvo_structsize,
2405                     sizeof(uint64_t));
2406                 error = SYSCTL_OUT(req, &kvo, kvo.kvo_structsize);
2407                 mtx_lock(&vm_object_list_mtx);
2408                 if (error)
2409                         break;
2410         }
2411         mtx_unlock(&vm_object_list_mtx);
2412         return (error);
2413 }
2414 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP |
2415     CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject",
2416     "List of VM objects");
2417
2418 #include "opt_ddb.h"
2419 #ifdef DDB
2420 #include <sys/kernel.h>
2421
2422 #include <sys/cons.h>
2423
2424 #include <ddb/ddb.h>
2425
2426 static int
2427 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
2428 {
2429         vm_map_t tmpm;
2430         vm_map_entry_t tmpe;
2431         vm_object_t obj;
2432         int entcount;
2433
2434         if (map == 0)
2435                 return 0;
2436
2437         if (entry == 0) {
2438                 tmpe = map->header.next;
2439                 entcount = map->nentries;
2440                 while (entcount-- && (tmpe != &map->header)) {
2441                         if (_vm_object_in_map(map, object, tmpe)) {
2442                                 return 1;
2443                         }
2444                         tmpe = tmpe->next;
2445                 }
2446         } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
2447                 tmpm = entry->object.sub_map;
2448                 tmpe = tmpm->header.next;
2449                 entcount = tmpm->nentries;
2450                 while (entcount-- && tmpe != &tmpm->header) {
2451                         if (_vm_object_in_map(tmpm, object, tmpe)) {
2452                                 return 1;
2453                         }
2454                         tmpe = tmpe->next;
2455                 }
2456         } else if ((obj = entry->object.vm_object) != NULL) {
2457                 for (; obj; obj = obj->backing_object)
2458                         if (obj == object) {
2459                                 return 1;
2460                         }
2461         }
2462         return 0;
2463 }
2464
2465 static int
2466 vm_object_in_map(vm_object_t object)
2467 {
2468         struct proc *p;
2469
2470         /* sx_slock(&allproc_lock); */
2471         FOREACH_PROC_IN_SYSTEM(p) {
2472                 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
2473                         continue;
2474                 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
2475                         /* sx_sunlock(&allproc_lock); */
2476                         return 1;
2477                 }
2478         }
2479         /* sx_sunlock(&allproc_lock); */
2480         if (_vm_object_in_map(kernel_map, object, 0))
2481                 return 1;
2482         return 0;
2483 }
2484
2485 DB_SHOW_COMMAND(vmochk, vm_object_check)
2486 {
2487         vm_object_t object;
2488
2489         /*
2490          * make sure that internal objs are in a map somewhere
2491          * and none have zero ref counts.
2492          */
2493         TAILQ_FOREACH(object, &vm_object_list, object_list) {
2494                 if (object->handle == NULL &&
2495                     (object->type == OBJT_DEFAULT || object->type == OBJT_SWAP)) {
2496                         if (object->ref_count == 0) {
2497                                 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2498                                         (long)object->size);
2499                         }
2500                         if (!vm_object_in_map(object)) {
2501                                 db_printf(
2502                         "vmochk: internal obj is not in a map: "
2503                         "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2504                                     object->ref_count, (u_long)object->size,
2505                                     (u_long)object->size,
2506                                     (void *)object->backing_object);
2507                         }
2508                 }
2509         }
2510 }
2511
2512 /*
2513  *      vm_object_print:        [ debug ]
2514  */
2515 DB_SHOW_COMMAND(object, vm_object_print_static)
2516 {
2517         /* XXX convert args. */
2518         vm_object_t object = (vm_object_t)addr;
2519         boolean_t full = have_addr;
2520
2521         vm_page_t p;
2522
2523         /* XXX count is an (unused) arg.  Avoid shadowing it. */
2524 #define count   was_count
2525
2526         int count;
2527
2528         if (object == NULL)
2529                 return;
2530
2531         db_iprintf(
2532             "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n",
2533             object, (int)object->type, (uintmax_t)object->size,
2534             object->resident_page_count, object->ref_count, object->flags,
2535             object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge);
2536         db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
2537             object->shadow_count,
2538             object->backing_object ? object->backing_object->ref_count : 0,
2539             object->backing_object, (uintmax_t)object->backing_object_offset);
2540
2541         if (!full)
2542                 return;
2543
2544         db_indent += 2;
2545         count = 0;
2546         TAILQ_FOREACH(p, &object->memq, listq) {
2547                 if (count == 0)
2548                         db_iprintf("memory:=");
2549                 else if (count == 6) {
2550                         db_printf("\n");
2551                         db_iprintf(" ...");
2552                         count = 0;
2553                 } else
2554                         db_printf(",");
2555                 count++;
2556
2557                 db_printf("(off=0x%jx,page=0x%jx)",
2558                     (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
2559         }
2560         if (count != 0)
2561                 db_printf("\n");
2562         db_indent -= 2;
2563 }
2564
2565 /* XXX. */
2566 #undef count
2567
2568 /* XXX need this non-static entry for calling from vm_map_print. */
2569 void
2570 vm_object_print(
2571         /* db_expr_t */ long addr,
2572         boolean_t have_addr,
2573         /* db_expr_t */ long count,
2574         char *modif)
2575 {
2576         vm_object_print_static(addr, have_addr, count, modif);
2577 }
2578
2579 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2580 {
2581         vm_object_t object;
2582         vm_pindex_t fidx;
2583         vm_paddr_t pa;
2584         vm_page_t m, prev_m;
2585         int rcount, nl, c;
2586
2587         nl = 0;
2588         TAILQ_FOREACH(object, &vm_object_list, object_list) {
2589                 db_printf("new object: %p\n", (void *)object);
2590                 if (nl > 18) {
2591                         c = cngetc();
2592                         if (c != ' ')
2593                                 return;
2594                         nl = 0;
2595                 }
2596                 nl++;
2597                 rcount = 0;
2598                 fidx = 0;
2599                 pa = -1;
2600                 TAILQ_FOREACH(m, &object->memq, listq) {
2601                         if (m->pindex > 128)
2602                                 break;
2603                         if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL &&
2604                             prev_m->pindex + 1 != m->pindex) {
2605                                 if (rcount) {
2606                                         db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2607                                                 (long)fidx, rcount, (long)pa);
2608                                         if (nl > 18) {
2609                                                 c = cngetc();
2610                                                 if (c != ' ')
2611                                                         return;
2612                                                 nl = 0;
2613                                         }
2614                                         nl++;
2615                                         rcount = 0;
2616                                 }
2617                         }
2618                         if (rcount &&
2619                                 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2620                                 ++rcount;
2621                                 continue;
2622                         }
2623                         if (rcount) {
2624                                 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2625                                         (long)fidx, rcount, (long)pa);
2626                                 if (nl > 18) {
2627                                         c = cngetc();
2628                                         if (c != ' ')
2629                                                 return;
2630                                         nl = 0;
2631                                 }
2632                                 nl++;
2633                         }
2634                         fidx = m->pindex;
2635                         pa = VM_PAGE_TO_PHYS(m);
2636                         rcount = 1;
2637                 }
2638                 if (rcount) {
2639                         db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2640                                 (long)fidx, rcount, (long)pa);
2641                         if (nl > 18) {
2642                                 c = cngetc();
2643                                 if (c != ' ')
2644                                         return;
2645                                 nl = 0;
2646                         }
2647                         nl++;
2648                 }
2649         }
2650 }
2651 #endif /* DDB */