2 * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
7 * This code is derived from software contributed to Berkeley by
8 * The Mach Operating System project at Carnegie-Mellon University.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * from: @(#)vm_object.c 8.5 (Berkeley) 3/22/94
37 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38 * All rights reserved.
40 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 * Carnegie Mellon requests users of this software to return to
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
64 * Virtual memory object module.
67 #include <sys/cdefs.h>
68 __FBSDID("$FreeBSD$");
72 #include <sys/param.h>
73 #include <sys/systm.h>
74 #include <sys/blockcount.h>
75 #include <sys/cpuset.h>
78 #include <sys/mount.h>
79 #include <sys/kernel.h>
80 #include <sys/pctrie.h>
81 #include <sys/sysctl.h>
82 #include <sys/mutex.h>
83 #include <sys/proc.h> /* for curproc, pageproc */
84 #include <sys/refcount.h>
85 #include <sys/socket.h>
86 #include <sys/resourcevar.h>
87 #include <sys/refcount.h>
88 #include <sys/rwlock.h>
90 #include <sys/vnode.h>
91 #include <sys/vmmeter.h>
95 #include <vm/vm_param.h>
97 #include <vm/vm_map.h>
98 #include <vm/vm_object.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_pageout.h>
101 #include <vm/vm_pager.h>
102 #include <vm/vm_phys.h>
103 #include <vm/vm_pagequeue.h>
104 #include <vm/swap_pager.h>
105 #include <vm/vm_kern.h>
106 #include <vm/vm_extern.h>
107 #include <vm/vm_radix.h>
108 #include <vm/vm_reserv.h>
111 static int old_msync;
112 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
113 "Use old (insecure) msync behavior");
115 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p,
116 int pagerflags, int flags, boolean_t *allclean,
118 static boolean_t vm_object_page_remove_write(vm_page_t p, int flags,
119 boolean_t *allclean);
120 static void vm_object_backing_remove(vm_object_t object);
123 * Virtual memory objects maintain the actual data
124 * associated with allocated virtual memory. A given
125 * page of memory exists within exactly one object.
127 * An object is only deallocated when all "references"
128 * are given up. Only one "reference" to a given
129 * region of an object should be writeable.
131 * Associated with each object is a list of all resident
132 * memory pages belonging to that object; this list is
133 * maintained by the "vm_page" module, and locked by the object's
136 * Each object also records a "pager" routine which is
137 * used to retrieve (and store) pages to the proper backing
138 * storage. In addition, objects may be backed by other
139 * objects from which they were virtual-copied.
141 * The only items within the object structure which are
142 * modified after time of creation are:
143 * reference count locked by object's lock
144 * pager routine locked by object's lock
148 struct object_q vm_object_list;
149 struct mtx vm_object_list_mtx; /* lock for object list and count */
151 struct vm_object kernel_object_store;
153 static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
156 static counter_u64_t object_collapses = EARLY_COUNTER;
157 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD,
159 "VM object collapses");
161 static counter_u64_t object_bypasses = EARLY_COUNTER;
162 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD,
164 "VM object bypasses");
166 static counter_u64_t object_collapse_waits = EARLY_COUNTER;
167 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapse_waits, CTLFLAG_RD,
168 &object_collapse_waits,
169 "Number of sleeps for collapse");
172 counter_startup(void)
175 object_collapses = counter_u64_alloc(M_WAITOK);
176 object_bypasses = counter_u64_alloc(M_WAITOK);
177 object_collapse_waits = counter_u64_alloc(M_WAITOK);
179 SYSINIT(object_counters, SI_SUB_CPU, SI_ORDER_ANY, counter_startup, NULL);
181 static uma_zone_t obj_zone;
183 static int vm_object_zinit(void *mem, int size, int flags);
186 static void vm_object_zdtor(void *mem, int size, void *arg);
189 vm_object_zdtor(void *mem, int size, void *arg)
193 object = (vm_object_t)mem;
194 KASSERT(object->ref_count == 0,
195 ("object %p ref_count = %d", object, object->ref_count));
196 KASSERT(TAILQ_EMPTY(&object->memq),
197 ("object %p has resident pages in its memq", object));
198 KASSERT(vm_radix_is_empty(&object->rtree),
199 ("object %p has resident pages in its trie", object));
200 #if VM_NRESERVLEVEL > 0
201 KASSERT(LIST_EMPTY(&object->rvq),
202 ("object %p has reservations",
205 KASSERT(blockcount_read(&object->paging_in_progress) == 0,
206 ("object %p paging_in_progress = %d",
207 object, blockcount_read(&object->paging_in_progress)));
208 KASSERT(!vm_object_busied(object),
209 ("object %p busy = %d", object, blockcount_read(&object->busy)));
210 KASSERT(object->resident_page_count == 0,
211 ("object %p resident_page_count = %d",
212 object, object->resident_page_count));
213 KASSERT(object->shadow_count == 0,
214 ("object %p shadow_count = %d",
215 object, object->shadow_count));
216 KASSERT(object->type == OBJT_DEAD,
217 ("object %p has non-dead type %d",
218 object, object->type));
223 vm_object_zinit(void *mem, int size, int flags)
227 object = (vm_object_t)mem;
228 rw_init_flags(&object->lock, "vm object", RW_DUPOK | RW_NEW);
230 /* These are true for any object that has been freed */
231 object->type = OBJT_DEAD;
232 vm_radix_init(&object->rtree);
233 refcount_init(&object->ref_count, 0);
234 blockcount_init(&object->paging_in_progress);
235 blockcount_init(&object->busy);
236 object->resident_page_count = 0;
237 object->shadow_count = 0;
238 object->flags = OBJ_DEAD;
240 mtx_lock(&vm_object_list_mtx);
241 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
242 mtx_unlock(&vm_object_list_mtx);
247 _vm_object_allocate(objtype_t type, vm_pindex_t size, u_short flags,
248 vm_object_t object, void *handle)
251 TAILQ_INIT(&object->memq);
252 LIST_INIT(&object->shadow_head);
255 if (type == OBJT_SWAP)
256 pctrie_init(&object->un_pager.swp.swp_blks);
259 * Ensure that swap_pager_swapoff() iteration over object_list
260 * sees up to date type and pctrie head if it observed
263 atomic_thread_fence_rel();
265 object->pg_color = 0;
266 object->flags = flags;
268 object->domain.dr_policy = NULL;
269 object->generation = 1;
270 object->cleangeneration = 1;
271 refcount_init(&object->ref_count, 1);
272 object->memattr = VM_MEMATTR_DEFAULT;
275 object->handle = handle;
276 object->backing_object = NULL;
277 object->backing_object_offset = (vm_ooffset_t) 0;
278 #if VM_NRESERVLEVEL > 0
279 LIST_INIT(&object->rvq);
281 umtx_shm_object_init(object);
287 * Initialize the VM objects module.
292 TAILQ_INIT(&vm_object_list);
293 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
295 rw_init(&kernel_object->lock, "kernel vm object");
296 _vm_object_allocate(OBJT_PHYS, atop(VM_MAX_KERNEL_ADDRESS -
297 VM_MIN_KERNEL_ADDRESS), OBJ_UNMANAGED, kernel_object, NULL);
298 #if VM_NRESERVLEVEL > 0
299 kernel_object->flags |= OBJ_COLORED;
300 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
304 * The lock portion of struct vm_object must be type stable due
305 * to vm_pageout_fallback_object_lock locking a vm object
306 * without holding any references to it.
308 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
314 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
320 vm_object_clear_flag(vm_object_t object, u_short bits)
323 VM_OBJECT_ASSERT_WLOCKED(object);
324 object->flags &= ~bits;
328 * Sets the default memory attribute for the specified object. Pages
329 * that are allocated to this object are by default assigned this memory
332 * Presently, this function must be called before any pages are allocated
333 * to the object. In the future, this requirement may be relaxed for
334 * "default" and "swap" objects.
337 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr)
340 VM_OBJECT_ASSERT_WLOCKED(object);
341 switch (object->type) {
349 if (!TAILQ_EMPTY(&object->memq))
350 return (KERN_FAILURE);
353 return (KERN_INVALID_ARGUMENT);
355 panic("vm_object_set_memattr: object %p is of undefined type",
358 object->memattr = memattr;
359 return (KERN_SUCCESS);
363 vm_object_pip_add(vm_object_t object, short i)
367 blockcount_acquire(&object->paging_in_progress, i);
371 vm_object_pip_wakeup(vm_object_t object)
374 vm_object_pip_wakeupn(object, 1);
378 vm_object_pip_wakeupn(vm_object_t object, short i)
382 blockcount_release(&object->paging_in_progress, i);
386 * Atomically drop the object lock and wait for pip to drain. This protects
387 * from sleep/wakeup races due to identity changes. The lock is not re-acquired
391 vm_object_pip_sleep(vm_object_t object, const char *waitid)
394 (void)blockcount_sleep(&object->paging_in_progress, &object->lock,
395 waitid, PVM | PDROP);
399 vm_object_pip_wait(vm_object_t object, const char *waitid)
402 VM_OBJECT_ASSERT_WLOCKED(object);
404 blockcount_wait(&object->paging_in_progress, &object->lock, waitid,
409 vm_object_pip_wait_unlocked(vm_object_t object, const char *waitid)
412 VM_OBJECT_ASSERT_UNLOCKED(object);
414 blockcount_wait(&object->paging_in_progress, NULL, waitid, PVM);
418 * vm_object_allocate:
420 * Returns a new object with the given size.
423 vm_object_allocate(objtype_t type, vm_pindex_t size)
430 panic("vm_object_allocate: can't create OBJT_DEAD");
437 flags = OBJ_FICTITIOUS | OBJ_UNMANAGED;
440 flags = OBJ_FICTITIOUS;
443 flags = OBJ_UNMANAGED;
449 panic("vm_object_allocate: type %d is undefined", type);
451 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK);
452 _vm_object_allocate(type, size, flags, object, NULL);
458 * vm_object_allocate_anon:
460 * Returns a new default object of the given size and marked as
461 * anonymous memory for special split/collapse handling. Color
462 * to be initialized by the caller.
465 vm_object_allocate_anon(vm_pindex_t size, vm_object_t backing_object,
466 struct ucred *cred, vm_size_t charge)
468 vm_object_t handle, object;
470 if (backing_object == NULL)
472 else if ((backing_object->flags & OBJ_ANON) != 0)
473 handle = backing_object->handle;
475 handle = backing_object;
476 object = uma_zalloc(obj_zone, M_WAITOK);
477 _vm_object_allocate(OBJT_DEFAULT, size, OBJ_ANON | OBJ_ONEMAPPING,
480 object->charge = cred != NULL ? charge : 0;
485 vm_object_reference_vnode(vm_object_t object)
490 * vnode objects need the lock for the first reference
491 * to serialize with vnode_object_deallocate().
493 if (!refcount_acquire_if_gt(&object->ref_count, 0)) {
494 VM_OBJECT_RLOCK(object);
495 old = refcount_acquire(&object->ref_count);
496 if (object->type == OBJT_VNODE && old == 0)
497 vref(object->handle);
498 VM_OBJECT_RUNLOCK(object);
503 * vm_object_reference:
505 * Acquires a reference to the given object.
508 vm_object_reference(vm_object_t object)
514 if (object->type == OBJT_VNODE)
515 vm_object_reference_vnode(object);
517 refcount_acquire(&object->ref_count);
518 KASSERT((object->flags & OBJ_DEAD) == 0,
519 ("vm_object_reference: Referenced dead object."));
523 * vm_object_reference_locked:
525 * Gets another reference to the given object.
527 * The object must be locked.
530 vm_object_reference_locked(vm_object_t object)
534 VM_OBJECT_ASSERT_LOCKED(object);
535 old = refcount_acquire(&object->ref_count);
536 if (object->type == OBJT_VNODE && old == 0)
537 vref(object->handle);
538 KASSERT((object->flags & OBJ_DEAD) == 0,
539 ("vm_object_reference: Referenced dead object."));
543 * Handle deallocating an object of type OBJT_VNODE.
546 vm_object_deallocate_vnode(vm_object_t object)
548 struct vnode *vp = (struct vnode *) object->handle;
551 KASSERT(object->type == OBJT_VNODE,
552 ("vm_object_deallocate_vnode: not a vnode object"));
553 KASSERT(vp != NULL, ("vm_object_deallocate_vnode: missing vp"));
555 /* Object lock to protect handle lookup. */
556 last = refcount_release(&object->ref_count);
557 VM_OBJECT_RUNLOCK(object);
562 if (!umtx_shm_vnobj_persistent)
563 umtx_shm_object_terminated(object);
565 /* vrele may need the vnode lock. */
571 * We dropped a reference on an object and discovered that it had a
572 * single remaining shadow. This is a sibling of the reference we
573 * dropped. Attempt to collapse the sibling and backing object.
576 vm_object_deallocate_anon(vm_object_t backing_object)
580 /* Fetch the final shadow. */
581 object = LIST_FIRST(&backing_object->shadow_head);
582 KASSERT(object != NULL && backing_object->shadow_count == 1,
583 ("vm_object_anon_deallocate: ref_count: %d, shadow_count: %d",
584 backing_object->ref_count, backing_object->shadow_count));
585 KASSERT((object->flags & (OBJ_TMPFS_NODE | OBJ_ANON)) == OBJ_ANON,
586 ("invalid shadow object %p", object));
588 if (!VM_OBJECT_TRYWLOCK(object)) {
590 * Prevent object from disappearing since we do not have a
593 vm_object_pip_add(object, 1);
594 VM_OBJECT_WUNLOCK(backing_object);
595 VM_OBJECT_WLOCK(object);
596 vm_object_pip_wakeup(object);
598 VM_OBJECT_WUNLOCK(backing_object);
601 * Check for a collapse/terminate race with the last reference holder.
603 if ((object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) != 0 ||
604 !refcount_acquire_if_not_zero(&object->ref_count)) {
605 VM_OBJECT_WUNLOCK(object);
608 backing_object = object->backing_object;
609 if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0)
610 vm_object_collapse(object);
611 VM_OBJECT_WUNLOCK(object);
617 * vm_object_deallocate:
619 * Release a reference to the specified object,
620 * gained either through a vm_object_allocate
621 * or a vm_object_reference call. When all references
622 * are gone, storage associated with this object
623 * may be relinquished.
625 * No object may be locked.
628 vm_object_deallocate(vm_object_t object)
633 while (object != NULL) {
635 * If the reference count goes to 0 we start calling
636 * vm_object_terminate() on the object chain. A ref count
637 * of 1 may be a special case depending on the shadow count
638 * being 0 or 1. These cases require a write lock on the
641 if ((object->flags & OBJ_ANON) == 0)
642 released = refcount_release_if_gt(&object->ref_count, 1);
644 released = refcount_release_if_gt(&object->ref_count, 2);
648 if (object->type == OBJT_VNODE) {
649 VM_OBJECT_RLOCK(object);
650 if (object->type == OBJT_VNODE) {
651 vm_object_deallocate_vnode(object);
654 VM_OBJECT_RUNLOCK(object);
657 VM_OBJECT_WLOCK(object);
658 KASSERT(object->ref_count > 0,
659 ("vm_object_deallocate: object deallocated too many times: %d",
663 * If this is not the final reference to an anonymous
664 * object we may need to collapse the shadow chain.
666 if (!refcount_release(&object->ref_count)) {
667 if (object->ref_count > 1 ||
668 object->shadow_count == 0) {
669 if ((object->flags & OBJ_ANON) != 0 &&
670 object->ref_count == 1)
671 vm_object_set_flag(object,
673 VM_OBJECT_WUNLOCK(object);
677 /* Handle collapsing last ref on anonymous objects. */
678 object = vm_object_deallocate_anon(object);
683 * Handle the final reference to an object. We restart
684 * the loop with the backing object to avoid recursion.
686 umtx_shm_object_terminated(object);
687 temp = object->backing_object;
689 KASSERT((object->flags & OBJ_TMPFS_NODE) == 0,
690 ("shadowed tmpfs v_object 2 %p", object));
691 vm_object_backing_remove(object);
694 KASSERT((object->flags & OBJ_DEAD) == 0,
695 ("vm_object_deallocate: Terminating dead object."));
696 vm_object_set_flag(object, OBJ_DEAD);
697 vm_object_terminate(object);
703 * vm_object_destroy removes the object from the global object list
704 * and frees the space for the object.
707 vm_object_destroy(vm_object_t object)
711 * Release the allocation charge.
713 if (object->cred != NULL) {
714 swap_release_by_cred(object->charge, object->cred);
716 crfree(object->cred);
721 * Free the space for the object.
723 uma_zfree(obj_zone, object);
727 vm_object_backing_remove_locked(vm_object_t object)
729 vm_object_t backing_object;
731 backing_object = object->backing_object;
732 VM_OBJECT_ASSERT_WLOCKED(object);
733 VM_OBJECT_ASSERT_WLOCKED(backing_object);
735 KASSERT((object->flags & OBJ_COLLAPSING) == 0,
736 ("vm_object_backing_remove: Removing collapsing object."));
738 if ((object->flags & OBJ_SHADOWLIST) != 0) {
739 LIST_REMOVE(object, shadow_list);
740 backing_object->shadow_count--;
741 object->flags &= ~OBJ_SHADOWLIST;
743 object->backing_object = NULL;
747 vm_object_backing_remove(vm_object_t object)
749 vm_object_t backing_object;
751 VM_OBJECT_ASSERT_WLOCKED(object);
753 if ((object->flags & OBJ_SHADOWLIST) != 0) {
754 backing_object = object->backing_object;
755 VM_OBJECT_WLOCK(backing_object);
756 vm_object_backing_remove_locked(object);
757 VM_OBJECT_WUNLOCK(backing_object);
759 object->backing_object = NULL;
763 vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object)
766 VM_OBJECT_ASSERT_WLOCKED(object);
768 if ((backing_object->flags & OBJ_ANON) != 0) {
769 VM_OBJECT_ASSERT_WLOCKED(backing_object);
770 LIST_INSERT_HEAD(&backing_object->shadow_head, object,
772 backing_object->shadow_count++;
773 object->flags |= OBJ_SHADOWLIST;
775 object->backing_object = backing_object;
779 vm_object_backing_insert(vm_object_t object, vm_object_t backing_object)
782 VM_OBJECT_ASSERT_WLOCKED(object);
784 if ((backing_object->flags & OBJ_ANON) != 0) {
785 VM_OBJECT_WLOCK(backing_object);
786 vm_object_backing_insert_locked(object, backing_object);
787 VM_OBJECT_WUNLOCK(backing_object);
789 object->backing_object = backing_object;
793 * Insert an object into a backing_object's shadow list with an additional
794 * reference to the backing_object added.
797 vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object)
800 VM_OBJECT_ASSERT_WLOCKED(object);
802 if ((backing_object->flags & OBJ_ANON) != 0) {
803 VM_OBJECT_WLOCK(backing_object);
804 KASSERT((backing_object->flags & OBJ_DEAD) == 0,
805 ("shadowing dead anonymous object"));
806 vm_object_reference_locked(backing_object);
807 vm_object_backing_insert_locked(object, backing_object);
808 vm_object_clear_flag(backing_object, OBJ_ONEMAPPING);
809 VM_OBJECT_WUNLOCK(backing_object);
811 vm_object_reference(backing_object);
812 object->backing_object = backing_object;
817 * Transfer a backing reference from backing_object to object.
820 vm_object_backing_transfer(vm_object_t object, vm_object_t backing_object)
822 vm_object_t new_backing_object;
825 * Note that the reference to backing_object->backing_object
826 * moves from within backing_object to within object.
828 vm_object_backing_remove_locked(object);
829 new_backing_object = backing_object->backing_object;
830 if (new_backing_object == NULL)
832 if ((new_backing_object->flags & OBJ_ANON) != 0) {
833 VM_OBJECT_WLOCK(new_backing_object);
834 vm_object_backing_remove_locked(backing_object);
835 vm_object_backing_insert_locked(object, new_backing_object);
836 VM_OBJECT_WUNLOCK(new_backing_object);
838 object->backing_object = new_backing_object;
839 backing_object->backing_object = NULL;
844 * Wait for a concurrent collapse to settle.
847 vm_object_collapse_wait(vm_object_t object)
850 VM_OBJECT_ASSERT_WLOCKED(object);
852 while ((object->flags & OBJ_COLLAPSING) != 0) {
853 vm_object_pip_wait(object, "vmcolwait");
854 counter_u64_add(object_collapse_waits, 1);
859 * Waits for a backing object to clear a pending collapse and returns
860 * it locked if it is an ANON object.
863 vm_object_backing_collapse_wait(vm_object_t object)
865 vm_object_t backing_object;
867 VM_OBJECT_ASSERT_WLOCKED(object);
870 backing_object = object->backing_object;
871 if (backing_object == NULL ||
872 (backing_object->flags & OBJ_ANON) == 0)
874 VM_OBJECT_WLOCK(backing_object);
875 if ((backing_object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) == 0)
877 VM_OBJECT_WUNLOCK(object);
878 vm_object_pip_sleep(backing_object, "vmbckwait");
879 counter_u64_add(object_collapse_waits, 1);
880 VM_OBJECT_WLOCK(object);
882 return (backing_object);
886 * vm_object_terminate_pages removes any remaining pageable pages
887 * from the object and resets the object to an empty state.
890 vm_object_terminate_pages(vm_object_t object)
894 VM_OBJECT_ASSERT_WLOCKED(object);
897 * Free any remaining pageable pages. This also removes them from the
898 * paging queues. However, don't free wired pages, just remove them
899 * from the object. Rather than incrementally removing each page from
900 * the object, the page and object are reset to any empty state.
902 TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) {
903 vm_page_assert_unbusied(p);
904 KASSERT(p->object == object &&
905 (p->ref_count & VPRC_OBJREF) != 0,
906 ("vm_object_terminate_pages: page %p is inconsistent", p));
909 if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) {
916 * If the object contained any pages, then reset it to an empty state.
917 * None of the object's fields, including "resident_page_count", were
918 * modified by the preceding loop.
920 if (object->resident_page_count != 0) {
921 vm_radix_reclaim_allnodes(&object->rtree);
922 TAILQ_INIT(&object->memq);
923 object->resident_page_count = 0;
924 if (object->type == OBJT_VNODE)
925 vdrop(object->handle);
930 * vm_object_terminate actually destroys the specified object, freeing
931 * up all previously used resources.
933 * The object must be locked.
934 * This routine may block.
937 vm_object_terminate(vm_object_t object)
940 VM_OBJECT_ASSERT_WLOCKED(object);
941 KASSERT((object->flags & OBJ_DEAD) != 0,
942 ("terminating non-dead obj %p", object));
943 KASSERT((object->flags & OBJ_COLLAPSING) == 0,
944 ("terminating collapsing obj %p", object));
945 KASSERT(object->backing_object == NULL,
946 ("terminating shadow obj %p", object));
949 * wait for the pageout daemon to be done with the object
951 vm_object_pip_wait(object, "objtrm");
953 KASSERT(!blockcount_read(&object->paging_in_progress),
954 ("vm_object_terminate: pageout in progress"));
956 KASSERT(object->ref_count == 0,
957 ("vm_object_terminate: object with references, ref_count=%d",
960 if ((object->flags & OBJ_PG_DTOR) == 0)
961 vm_object_terminate_pages(object);
963 #if VM_NRESERVLEVEL > 0
964 if (__predict_false(!LIST_EMPTY(&object->rvq)))
965 vm_reserv_break_all(object);
968 KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT ||
969 object->type == OBJT_SWAP,
970 ("%s: non-swap obj %p has cred", __func__, object));
973 * Let the pager know object is dead.
975 vm_pager_deallocate(object);
976 VM_OBJECT_WUNLOCK(object);
978 vm_object_destroy(object);
982 * Make the page read-only so that we can clear the object flags. However, if
983 * this is a nosync mmap then the object is likely to stay dirty so do not
984 * mess with the page and do not clear the object flags. Returns TRUE if the
985 * page should be flushed, and FALSE otherwise.
988 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean)
991 vm_page_assert_busied(p);
994 * If we have been asked to skip nosync pages and this is a
995 * nosync page, skip it. Note that the object flags were not
996 * cleared in this case so we do not have to set them.
998 if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) {
1002 pmap_remove_write(p);
1003 return (p->dirty != 0);
1008 * vm_object_page_clean
1010 * Clean all dirty pages in the specified range of object. Leaves page
1011 * on whatever queue it is currently on. If NOSYNC is set then do not
1012 * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC),
1013 * leaving the object dirty.
1015 * For swap objects backing tmpfs regular files, do not flush anything,
1016 * but remove write protection on the mapped pages to update mtime through
1019 * When stuffing pages asynchronously, allow clustering. XXX we need a
1020 * synchronous clustering mode implementation.
1022 * Odd semantics: if start == end, we clean everything.
1024 * The object must be locked.
1026 * Returns FALSE if some page from the range was not written, as
1027 * reported by the pager, and TRUE otherwise.
1030 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end,
1034 vm_pindex_t pi, tend, tstart;
1035 int curgeneration, n, pagerflags;
1036 boolean_t eio, res, allclean;
1038 VM_OBJECT_ASSERT_WLOCKED(object);
1040 if (!vm_object_mightbedirty(object) || object->resident_page_count == 0)
1043 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ?
1044 VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
1045 pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0;
1047 tstart = OFF_TO_IDX(start);
1048 tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK);
1049 allclean = tstart == 0 && tend >= object->size;
1053 curgeneration = object->generation;
1055 for (p = vm_page_find_least(object, tstart); p != NULL; p = np) {
1059 np = TAILQ_NEXT(p, listq);
1060 if (vm_page_none_valid(p))
1062 if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) {
1063 if (object->generation != curgeneration &&
1064 (flags & OBJPC_SYNC) != 0)
1066 np = vm_page_find_least(object, pi);
1069 if (!vm_object_page_remove_write(p, flags, &allclean)) {
1073 if (object->type == OBJT_VNODE) {
1074 n = vm_object_page_collect_flush(object, p, pagerflags,
1075 flags, &allclean, &eio);
1080 if (object->generation != curgeneration &&
1081 (flags & OBJPC_SYNC) != 0)
1085 * If the VOP_PUTPAGES() did a truncated write, so
1086 * that even the first page of the run is not fully
1087 * written, vm_pageout_flush() returns 0 as the run
1088 * length. Since the condition that caused truncated
1089 * write may be permanent, e.g. exhausted free space,
1090 * accepting n == 0 would cause an infinite loop.
1092 * Forwarding the iterator leaves the unwritten page
1093 * behind, but there is not much we can do there if
1094 * filesystem refuses to write it.
1104 np = vm_page_find_least(object, pi + n);
1107 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0);
1111 * Leave updating cleangeneration for tmpfs objects to tmpfs
1112 * scan. It needs to update mtime, which happens for other
1113 * filesystems during page writeouts.
1115 if (allclean && object->type == OBJT_VNODE)
1116 object->cleangeneration = curgeneration;
1121 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags,
1122 int flags, boolean_t *allclean, boolean_t *eio)
1124 vm_page_t ma[vm_pageout_page_count], p_first, tp;
1125 int count, i, mreq, runlen;
1127 vm_page_lock_assert(p, MA_NOTOWNED);
1128 vm_page_assert_xbusied(p);
1129 VM_OBJECT_ASSERT_WLOCKED(object);
1134 for (tp = p; count < vm_pageout_page_count; count++) {
1135 tp = vm_page_next(tp);
1136 if (tp == NULL || vm_page_tryxbusy(tp) == 0)
1138 if (!vm_object_page_remove_write(tp, flags, allclean)) {
1139 vm_page_xunbusy(tp);
1144 for (p_first = p; count < vm_pageout_page_count; count++) {
1145 tp = vm_page_prev(p_first);
1146 if (tp == NULL || vm_page_tryxbusy(tp) == 0)
1148 if (!vm_object_page_remove_write(tp, flags, allclean)) {
1149 vm_page_xunbusy(tp);
1156 for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
1159 vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
1164 * Note that there is absolutely no sense in writing out
1165 * anonymous objects, so we track down the vnode object
1167 * We invalidate (remove) all pages from the address space
1168 * for semantic correctness.
1170 * If the backing object is a device object with unmanaged pages, then any
1171 * mappings to the specified range of pages must be removed before this
1172 * function is called.
1174 * Note: certain anonymous maps, such as MAP_NOSYNC maps,
1175 * may start out with a NULL object.
1178 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
1179 boolean_t syncio, boolean_t invalidate)
1181 vm_object_t backing_object;
1184 int error, flags, fsync_after;
1191 VM_OBJECT_WLOCK(object);
1192 while ((backing_object = object->backing_object) != NULL) {
1193 VM_OBJECT_WLOCK(backing_object);
1194 offset += object->backing_object_offset;
1195 VM_OBJECT_WUNLOCK(object);
1196 object = backing_object;
1197 if (object->size < OFF_TO_IDX(offset + size))
1198 size = IDX_TO_OFF(object->size) - offset;
1201 * Flush pages if writing is allowed, invalidate them
1202 * if invalidation requested. Pages undergoing I/O
1203 * will be ignored by vm_object_page_remove().
1205 * We cannot lock the vnode and then wait for paging
1206 * to complete without deadlocking against vm_fault.
1207 * Instead we simply call vm_object_page_remove() and
1208 * allow it to block internally on a page-by-page
1209 * basis when it encounters pages undergoing async
1212 if (object->type == OBJT_VNODE &&
1213 vm_object_mightbedirty(object) != 0 &&
1214 ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) {
1215 VM_OBJECT_WUNLOCK(object);
1216 (void) vn_start_write(vp, &mp, V_WAIT);
1217 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1218 if (syncio && !invalidate && offset == 0 &&
1219 atop(size) == object->size) {
1221 * If syncing the whole mapping of the file,
1222 * it is faster to schedule all the writes in
1223 * async mode, also allowing the clustering,
1224 * and then wait for i/o to complete.
1229 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
1230 flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0;
1231 fsync_after = FALSE;
1233 VM_OBJECT_WLOCK(object);
1234 res = vm_object_page_clean(object, offset, offset + size,
1236 VM_OBJECT_WUNLOCK(object);
1238 error = VOP_FSYNC(vp, MNT_WAIT, curthread);
1240 vn_finished_write(mp);
1243 VM_OBJECT_WLOCK(object);
1245 if ((object->type == OBJT_VNODE ||
1246 object->type == OBJT_DEVICE) && invalidate) {
1247 if (object->type == OBJT_DEVICE)
1249 * The option OBJPR_NOTMAPPED must be passed here
1250 * because vm_object_page_remove() cannot remove
1251 * unmanaged mappings.
1253 flags = OBJPR_NOTMAPPED;
1257 flags = OBJPR_CLEANONLY;
1258 vm_object_page_remove(object, OFF_TO_IDX(offset),
1259 OFF_TO_IDX(offset + size + PAGE_MASK), flags);
1261 VM_OBJECT_WUNLOCK(object);
1266 * Determine whether the given advice can be applied to the object. Advice is
1267 * not applied to unmanaged pages since they never belong to page queues, and
1268 * since MADV_FREE is destructive, it can apply only to anonymous pages that
1269 * have been mapped at most once.
1272 vm_object_advice_applies(vm_object_t object, int advice)
1275 if ((object->flags & OBJ_UNMANAGED) != 0)
1277 if (advice != MADV_FREE)
1279 return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) ==
1280 (OBJ_ONEMAPPING | OBJ_ANON));
1284 vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex,
1288 if (advice == MADV_FREE && object->type == OBJT_SWAP)
1289 swap_pager_freespace(object, pindex, size);
1293 * vm_object_madvise:
1295 * Implements the madvise function at the object/page level.
1297 * MADV_WILLNEED (any object)
1299 * Activate the specified pages if they are resident.
1301 * MADV_DONTNEED (any object)
1303 * Deactivate the specified pages if they are resident.
1305 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
1306 * OBJ_ONEMAPPING only)
1308 * Deactivate and clean the specified pages if they are
1309 * resident. This permits the process to reuse the pages
1310 * without faulting or the kernel to reclaim the pages
1314 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end,
1317 vm_pindex_t tpindex;
1318 vm_object_t backing_object, tobject;
1325 VM_OBJECT_WLOCK(object);
1326 if (!vm_object_advice_applies(object, advice)) {
1327 VM_OBJECT_WUNLOCK(object);
1330 for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) {
1334 * If the next page isn't resident in the top-level object, we
1335 * need to search the shadow chain. When applying MADV_FREE, we
1336 * take care to release any swap space used to store
1337 * non-resident pages.
1339 if (m == NULL || pindex < m->pindex) {
1341 * Optimize a common case: if the top-level object has
1342 * no backing object, we can skip over the non-resident
1343 * range in constant time.
1345 if (object->backing_object == NULL) {
1346 tpindex = (m != NULL && m->pindex < end) ?
1348 vm_object_madvise_freespace(object, advice,
1349 pindex, tpindex - pindex);
1350 if ((pindex = tpindex) == end)
1357 vm_object_madvise_freespace(tobject, advice,
1360 * Prepare to search the next object in the
1363 backing_object = tobject->backing_object;
1364 if (backing_object == NULL)
1366 VM_OBJECT_WLOCK(backing_object);
1368 OFF_TO_IDX(tobject->backing_object_offset);
1369 if (tobject != object)
1370 VM_OBJECT_WUNLOCK(tobject);
1371 tobject = backing_object;
1372 if (!vm_object_advice_applies(tobject, advice))
1374 } while ((tm = vm_page_lookup(tobject, tpindex)) ==
1379 m = TAILQ_NEXT(m, listq);
1383 * If the page is not in a normal state, skip it. The page
1384 * can not be invalidated while the object lock is held.
1386 if (!vm_page_all_valid(tm) || vm_page_wired(tm))
1388 KASSERT((tm->flags & PG_FICTITIOUS) == 0,
1389 ("vm_object_madvise: page %p is fictitious", tm));
1390 KASSERT((tm->oflags & VPO_UNMANAGED) == 0,
1391 ("vm_object_madvise: page %p is not managed", tm));
1392 if (vm_page_tryxbusy(tm) == 0) {
1393 if (object != tobject)
1394 VM_OBJECT_WUNLOCK(object);
1395 if (advice == MADV_WILLNEED) {
1397 * Reference the page before unlocking and
1398 * sleeping so that the page daemon is less
1399 * likely to reclaim it.
1401 vm_page_aflag_set(tm, PGA_REFERENCED);
1403 vm_page_busy_sleep(tm, "madvpo", false);
1406 vm_page_advise(tm, advice);
1407 vm_page_xunbusy(tm);
1408 vm_object_madvise_freespace(tobject, advice, tm->pindex, 1);
1410 if (tobject != object)
1411 VM_OBJECT_WUNLOCK(tobject);
1413 VM_OBJECT_WUNLOCK(object);
1419 * Create a new object which is backed by the
1420 * specified existing object range. The source
1421 * object reference is deallocated.
1423 * The new object and offset into that object
1424 * are returned in the source parameters.
1427 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length,
1428 struct ucred *cred, bool shared)
1436 * Don't create the new object if the old object isn't shared.
1438 * If we hold the only reference we can guarantee that it won't
1439 * increase while we have the map locked. Otherwise the race is
1440 * harmless and we will end up with an extra shadow object that
1441 * will be collapsed later.
1443 if (source != NULL && source->ref_count == 1 &&
1444 (source->flags & OBJ_ANON) != 0)
1448 * Allocate a new object with the given length.
1450 result = vm_object_allocate_anon(atop(length), source, cred, length);
1453 * Store the offset into the source object, and fix up the offset into
1456 result->backing_object_offset = *offset;
1458 if (shared || source != NULL) {
1459 VM_OBJECT_WLOCK(result);
1462 * The new object shadows the source object, adding a
1463 * reference to it. Our caller changes his reference
1464 * to point to the new object, removing a reference to
1465 * the source object. Net result: no change of
1466 * reference count, unless the caller needs to add one
1467 * more reference due to forking a shared map entry.
1470 vm_object_reference_locked(result);
1471 vm_object_clear_flag(result, OBJ_ONEMAPPING);
1475 * Try to optimize the result object's page color when
1476 * shadowing in order to maintain page coloring
1477 * consistency in the combined shadowed object.
1479 if (source != NULL) {
1480 vm_object_backing_insert(result, source);
1481 result->domain = source->domain;
1482 #if VM_NRESERVLEVEL > 0
1483 result->flags |= source->flags & OBJ_COLORED;
1484 result->pg_color = (source->pg_color +
1485 OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER -
1489 VM_OBJECT_WUNLOCK(result);
1493 * Return the new things
1502 * Split the pages in a map entry into a new object. This affords
1503 * easier removal of unused pages, and keeps object inheritance from
1504 * being a negative impact on memory usage.
1507 vm_object_split(vm_map_entry_t entry)
1509 vm_page_t m, m_next;
1510 vm_object_t orig_object, new_object, backing_object;
1511 vm_pindex_t idx, offidxstart;
1514 orig_object = entry->object.vm_object;
1515 KASSERT((orig_object->flags & OBJ_ONEMAPPING) != 0,
1516 ("vm_object_split: Splitting object with multiple mappings."));
1517 if ((orig_object->flags & OBJ_ANON) == 0)
1519 if (orig_object->ref_count <= 1)
1521 VM_OBJECT_WUNLOCK(orig_object);
1523 offidxstart = OFF_TO_IDX(entry->offset);
1524 size = atop(entry->end - entry->start);
1527 * If swap_pager_copy() is later called, it will convert new_object
1528 * into a swap object.
1530 new_object = vm_object_allocate_anon(size, orig_object,
1531 orig_object->cred, ptoa(size));
1534 * We must wait for the orig_object to complete any in-progress
1535 * collapse so that the swap blocks are stable below. The
1536 * additional reference on backing_object by new object will
1537 * prevent further collapse operations until split completes.
1539 VM_OBJECT_WLOCK(orig_object);
1540 vm_object_collapse_wait(orig_object);
1543 * At this point, the new object is still private, so the order in
1544 * which the original and new objects are locked does not matter.
1546 VM_OBJECT_WLOCK(new_object);
1547 new_object->domain = orig_object->domain;
1548 backing_object = orig_object->backing_object;
1549 if (backing_object != NULL) {
1550 vm_object_backing_insert_ref(new_object, backing_object);
1551 new_object->backing_object_offset =
1552 orig_object->backing_object_offset + entry->offset;
1554 if (orig_object->cred != NULL) {
1555 crhold(orig_object->cred);
1556 KASSERT(orig_object->charge >= ptoa(size),
1557 ("orig_object->charge < 0"));
1558 orig_object->charge -= ptoa(size);
1562 * Mark the split operation so that swap_pager_getpages() knows
1563 * that the object is in transition.
1565 vm_object_set_flag(orig_object, OBJ_SPLIT);
1567 m = vm_page_find_least(orig_object, offidxstart);
1568 for (; m != NULL && (idx = m->pindex - offidxstart) < size;
1570 m_next = TAILQ_NEXT(m, listq);
1573 * We must wait for pending I/O to complete before we can
1576 * We do not have to VM_PROT_NONE the page as mappings should
1577 * not be changed by this operation.
1579 if (vm_page_tryxbusy(m) == 0) {
1580 VM_OBJECT_WUNLOCK(new_object);
1581 vm_page_sleep_if_busy(m, "spltwt");
1582 VM_OBJECT_WLOCK(new_object);
1587 * The page was left invalid. Likely placed there by
1588 * an incomplete fault. Just remove and ignore.
1590 if (vm_page_none_valid(m)) {
1591 if (vm_page_remove(m))
1596 /* vm_page_rename() will dirty the page. */
1597 if (vm_page_rename(m, new_object, idx)) {
1599 VM_OBJECT_WUNLOCK(new_object);
1600 VM_OBJECT_WUNLOCK(orig_object);
1602 VM_OBJECT_WLOCK(orig_object);
1603 VM_OBJECT_WLOCK(new_object);
1607 #if VM_NRESERVLEVEL > 0
1609 * If some of the reservation's allocated pages remain with
1610 * the original object, then transferring the reservation to
1611 * the new object is neither particularly beneficial nor
1612 * particularly harmful as compared to leaving the reservation
1613 * with the original object. If, however, all of the
1614 * reservation's allocated pages are transferred to the new
1615 * object, then transferring the reservation is typically
1616 * beneficial. Determining which of these two cases applies
1617 * would be more costly than unconditionally renaming the
1620 vm_reserv_rename(m, new_object, orig_object, offidxstart);
1622 if (orig_object->type != OBJT_SWAP)
1625 if (orig_object->type == OBJT_SWAP) {
1627 * swap_pager_copy() can sleep, in which case the orig_object's
1628 * and new_object's locks are released and reacquired.
1630 swap_pager_copy(orig_object, new_object, offidxstart, 0);
1631 TAILQ_FOREACH(m, &new_object->memq, listq)
1634 vm_object_clear_flag(orig_object, OBJ_SPLIT);
1635 VM_OBJECT_WUNLOCK(orig_object);
1636 VM_OBJECT_WUNLOCK(new_object);
1637 entry->object.vm_object = new_object;
1638 entry->offset = 0LL;
1639 vm_object_deallocate(orig_object);
1640 VM_OBJECT_WLOCK(new_object);
1644 vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p)
1646 vm_object_t backing_object;
1648 VM_OBJECT_ASSERT_WLOCKED(object);
1649 backing_object = object->backing_object;
1650 VM_OBJECT_ASSERT_WLOCKED(backing_object);
1652 KASSERT(p == NULL || p->object == object || p->object == backing_object,
1653 ("invalid ownership %p %p %p", p, object, backing_object));
1654 /* The page is only NULL when rename fails. */
1656 VM_OBJECT_WUNLOCK(object);
1657 VM_OBJECT_WUNLOCK(backing_object);
1660 if (p->object == object)
1661 VM_OBJECT_WUNLOCK(backing_object);
1663 VM_OBJECT_WUNLOCK(object);
1664 vm_page_busy_sleep(p, "vmocol", false);
1666 VM_OBJECT_WLOCK(object);
1667 VM_OBJECT_WLOCK(backing_object);
1668 return (TAILQ_FIRST(&backing_object->memq));
1672 vm_object_scan_all_shadowed(vm_object_t object)
1674 vm_object_t backing_object;
1676 vm_pindex_t backing_offset_index, new_pindex, pi, ps;
1678 VM_OBJECT_ASSERT_WLOCKED(object);
1679 VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
1681 backing_object = object->backing_object;
1683 if ((backing_object->flags & OBJ_ANON) == 0)
1686 pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1687 p = vm_page_find_least(backing_object, pi);
1688 ps = swap_pager_find_least(backing_object, pi);
1691 * Only check pages inside the parent object's range and
1692 * inside the parent object's mapping of the backing object.
1695 if (p != NULL && p->pindex < pi)
1696 p = TAILQ_NEXT(p, listq);
1698 ps = swap_pager_find_least(backing_object, pi);
1699 if (p == NULL && ps >= backing_object->size)
1704 pi = MIN(p->pindex, ps);
1706 new_pindex = pi - backing_offset_index;
1707 if (new_pindex >= object->size)
1712 * If the backing object page is busy a
1713 * grandparent or older page may still be
1714 * undergoing CoW. It is not safe to collapse
1715 * the backing object until it is quiesced.
1717 if (vm_page_tryxbusy(p) == 0)
1721 * We raced with the fault handler that left
1722 * newly allocated invalid page on the object
1723 * queue and retried.
1725 if (!vm_page_all_valid(p))
1730 * See if the parent has the page or if the parent's object
1731 * pager has the page. If the parent has the page but the page
1732 * is not valid, the parent's object pager must have the page.
1734 * If this fails, the parent does not completely shadow the
1735 * object and we might as well give up now.
1737 pp = vm_page_lookup(object, new_pindex);
1740 * The valid check here is stable due to object lock
1741 * being required to clear valid and initiate paging.
1742 * Busy of p disallows fault handler to validate pp.
1744 if ((pp == NULL || vm_page_none_valid(pp)) &&
1745 !vm_pager_has_page(object, new_pindex, NULL, NULL))
1759 vm_object_collapse_scan(vm_object_t object)
1761 vm_object_t backing_object;
1762 vm_page_t next, p, pp;
1763 vm_pindex_t backing_offset_index, new_pindex;
1765 VM_OBJECT_ASSERT_WLOCKED(object);
1766 VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
1768 backing_object = object->backing_object;
1769 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1774 for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) {
1775 next = TAILQ_NEXT(p, listq);
1776 new_pindex = p->pindex - backing_offset_index;
1779 * Check for busy page
1781 if (vm_page_tryxbusy(p) == 0) {
1782 next = vm_object_collapse_scan_wait(object, p);
1786 KASSERT(object->backing_object == backing_object,
1787 ("vm_object_collapse_scan: backing object mismatch %p != %p",
1788 object->backing_object, backing_object));
1789 KASSERT(p->object == backing_object,
1790 ("vm_object_collapse_scan: object mismatch %p != %p",
1791 p->object, backing_object));
1793 if (p->pindex < backing_offset_index ||
1794 new_pindex >= object->size) {
1795 if (backing_object->type == OBJT_SWAP)
1796 swap_pager_freespace(backing_object, p->pindex,
1799 KASSERT(!pmap_page_is_mapped(p),
1800 ("freeing mapped page %p", p));
1801 if (vm_page_remove(p))
1806 if (!vm_page_all_valid(p)) {
1807 KASSERT(!pmap_page_is_mapped(p),
1808 ("freeing mapped page %p", p));
1809 if (vm_page_remove(p))
1814 pp = vm_page_lookup(object, new_pindex);
1815 if (pp != NULL && vm_page_tryxbusy(pp) == 0) {
1818 * The page in the parent is busy and possibly not
1819 * (yet) valid. Until its state is finalized by the
1820 * busy bit owner, we can't tell whether it shadows the
1823 next = vm_object_collapse_scan_wait(object, pp);
1827 if (pp != NULL && vm_page_none_valid(pp)) {
1829 * The page was invalid in the parent. Likely placed
1830 * there by an incomplete fault. Just remove and
1831 * ignore. p can replace it.
1833 if (vm_page_remove(pp))
1838 if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL,
1841 * The page already exists in the parent OR swap exists
1842 * for this location in the parent. Leave the parent's
1843 * page alone. Destroy the original page from the
1846 if (backing_object->type == OBJT_SWAP)
1847 swap_pager_freespace(backing_object, p->pindex,
1849 KASSERT(!pmap_page_is_mapped(p),
1850 ("freeing mapped page %p", p));
1851 if (vm_page_remove(p))
1854 vm_page_xunbusy(pp);
1859 * Page does not exist in parent, rename the page from the
1860 * backing object to the main object.
1862 * If the page was mapped to a process, it can remain mapped
1863 * through the rename. vm_page_rename() will dirty the page.
1865 if (vm_page_rename(p, object, new_pindex)) {
1867 next = vm_object_collapse_scan_wait(object, NULL);
1871 /* Use the old pindex to free the right page. */
1872 if (backing_object->type == OBJT_SWAP)
1873 swap_pager_freespace(backing_object,
1874 new_pindex + backing_offset_index, 1);
1876 #if VM_NRESERVLEVEL > 0
1878 * Rename the reservation.
1880 vm_reserv_rename(p, object, backing_object,
1881 backing_offset_index);
1889 * vm_object_collapse:
1891 * Collapse an object with the object backing it.
1892 * Pages in the backing object are moved into the
1893 * parent, and the backing object is deallocated.
1896 vm_object_collapse(vm_object_t object)
1898 vm_object_t backing_object, new_backing_object;
1900 VM_OBJECT_ASSERT_WLOCKED(object);
1903 KASSERT((object->flags & (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON,
1904 ("collapsing invalid object"));
1907 * Wait for the backing_object to finish any pending
1908 * collapse so that the caller sees the shortest possible
1911 backing_object = vm_object_backing_collapse_wait(object);
1912 if (backing_object == NULL)
1915 KASSERT(object->ref_count > 0 &&
1916 object->ref_count > object->shadow_count,
1917 ("collapse with invalid ref %d or shadow %d count.",
1918 object->ref_count, object->shadow_count));
1919 KASSERT((backing_object->flags &
1920 (OBJ_COLLAPSING | OBJ_DEAD)) == 0,
1921 ("vm_object_collapse: Backing object already collapsing."));
1922 KASSERT((object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0,
1923 ("vm_object_collapse: object is already collapsing."));
1926 * We know that we can either collapse the backing object if
1927 * the parent is the only reference to it, or (perhaps) have
1928 * the parent bypass the object if the parent happens to shadow
1929 * all the resident pages in the entire backing object.
1931 if (backing_object->ref_count == 1) {
1932 KASSERT(backing_object->shadow_count == 1,
1933 ("vm_object_collapse: shadow_count: %d",
1934 backing_object->shadow_count));
1935 vm_object_pip_add(object, 1);
1936 vm_object_set_flag(object, OBJ_COLLAPSING);
1937 vm_object_pip_add(backing_object, 1);
1938 vm_object_set_flag(backing_object, OBJ_DEAD);
1941 * If there is exactly one reference to the backing
1942 * object, we can collapse it into the parent.
1944 vm_object_collapse_scan(object);
1946 #if VM_NRESERVLEVEL > 0
1948 * Break any reservations from backing_object.
1950 if (__predict_false(!LIST_EMPTY(&backing_object->rvq)))
1951 vm_reserv_break_all(backing_object);
1955 * Move the pager from backing_object to object.
1957 if (backing_object->type == OBJT_SWAP) {
1959 * swap_pager_copy() can sleep, in which case
1960 * the backing_object's and object's locks are
1961 * released and reacquired.
1962 * Since swap_pager_copy() is being asked to
1963 * destroy backing_object, it will change the
1964 * type to OBJT_DEFAULT.
1969 OFF_TO_IDX(object->backing_object_offset), TRUE);
1973 * Object now shadows whatever backing_object did.
1975 vm_object_clear_flag(object, OBJ_COLLAPSING);
1976 vm_object_backing_transfer(object, backing_object);
1977 object->backing_object_offset +=
1978 backing_object->backing_object_offset;
1979 VM_OBJECT_WUNLOCK(object);
1980 vm_object_pip_wakeup(object);
1983 * Discard backing_object.
1985 * Since the backing object has no pages, no pager left,
1986 * and no object references within it, all that is
1987 * necessary is to dispose of it.
1989 KASSERT(backing_object->ref_count == 1, (
1990 "backing_object %p was somehow re-referenced during collapse!",
1992 vm_object_pip_wakeup(backing_object);
1993 (void)refcount_release(&backing_object->ref_count);
1994 vm_object_terminate(backing_object);
1995 counter_u64_add(object_collapses, 1);
1996 VM_OBJECT_WLOCK(object);
1999 * If we do not entirely shadow the backing object,
2000 * there is nothing we can do so we give up.
2002 * The object lock and backing_object lock must not
2003 * be dropped during this sequence.
2005 if (!vm_object_scan_all_shadowed(object)) {
2006 VM_OBJECT_WUNLOCK(backing_object);
2011 * Make the parent shadow the next object in the
2012 * chain. Deallocating backing_object will not remove
2013 * it, since its reference count is at least 2.
2015 vm_object_backing_remove_locked(object);
2016 new_backing_object = backing_object->backing_object;
2017 if (new_backing_object != NULL) {
2018 vm_object_backing_insert_ref(object,
2019 new_backing_object);
2020 object->backing_object_offset +=
2021 backing_object->backing_object_offset;
2025 * Drop the reference count on backing_object. Since
2026 * its ref_count was at least 2, it will not vanish.
2028 (void)refcount_release(&backing_object->ref_count);
2029 KASSERT(backing_object->ref_count >= 1, (
2030 "backing_object %p was somehow dereferenced during collapse!",
2032 VM_OBJECT_WUNLOCK(backing_object);
2033 counter_u64_add(object_bypasses, 1);
2037 * Try again with this object's new backing object.
2043 * vm_object_page_remove:
2045 * For the given object, either frees or invalidates each of the
2046 * specified pages. In general, a page is freed. However, if a page is
2047 * wired for any reason other than the existence of a managed, wired
2048 * mapping, then it may be invalidated but not removed from the object.
2049 * Pages are specified by the given range ["start", "end") and the option
2050 * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range
2051 * extends from "start" to the end of the object. If the option
2052 * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the
2053 * specified range are affected. If the option OBJPR_NOTMAPPED is
2054 * specified, then the pages within the specified range must have no
2055 * mappings. Otherwise, if this option is not specified, any mappings to
2056 * the specified pages are removed before the pages are freed or
2059 * In general, this operation should only be performed on objects that
2060 * contain managed pages. There are, however, two exceptions. First, it
2061 * is performed on the kernel and kmem objects by vm_map_entry_delete().
2062 * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device-
2063 * backed pages. In both of these cases, the option OBJPR_CLEANONLY must
2064 * not be specified and the option OBJPR_NOTMAPPED must be specified.
2066 * The object must be locked.
2069 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
2074 VM_OBJECT_ASSERT_WLOCKED(object);
2075 KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
2076 (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
2077 ("vm_object_page_remove: illegal options for object %p", object));
2078 if (object->resident_page_count == 0)
2080 vm_object_pip_add(object, 1);
2082 p = vm_page_find_least(object, start);
2085 * Here, the variable "p" is either (1) the page with the least pindex
2086 * greater than or equal to the parameter "start" or (2) NULL.
2088 for (; p != NULL && (p->pindex < end || end == 0); p = next) {
2089 next = TAILQ_NEXT(p, listq);
2092 * If the page is wired for any reason besides the existence
2093 * of managed, wired mappings, then it cannot be freed. For
2094 * example, fictitious pages, which represent device memory,
2095 * are inherently wired and cannot be freed. They can,
2096 * however, be invalidated if the option OBJPR_CLEANONLY is
2099 if (vm_page_tryxbusy(p) == 0) {
2100 vm_page_sleep_if_busy(p, "vmopar");
2103 if (vm_page_wired(p)) {
2105 if ((options & OBJPR_NOTMAPPED) == 0 &&
2106 object->ref_count != 0)
2108 if ((options & OBJPR_CLEANONLY) == 0) {
2115 KASSERT((p->flags & PG_FICTITIOUS) == 0,
2116 ("vm_object_page_remove: page %p is fictitious", p));
2117 if ((options & OBJPR_CLEANONLY) != 0 &&
2118 !vm_page_none_valid(p)) {
2119 if ((options & OBJPR_NOTMAPPED) == 0 &&
2120 object->ref_count != 0 &&
2121 !vm_page_try_remove_write(p))
2123 if (p->dirty != 0) {
2128 if ((options & OBJPR_NOTMAPPED) == 0 &&
2129 object->ref_count != 0 && !vm_page_try_remove_all(p))
2133 vm_object_pip_wakeup(object);
2137 * vm_object_page_noreuse:
2139 * For the given object, attempt to move the specified pages to
2140 * the head of the inactive queue. This bypasses regular LRU
2141 * operation and allows the pages to be reused quickly under memory
2142 * pressure. If a page is wired for any reason, then it will not
2143 * be queued. Pages are specified by the range ["start", "end").
2144 * As a special case, if "end" is zero, then the range extends from
2145 * "start" to the end of the object.
2147 * This operation should only be performed on objects that
2148 * contain non-fictitious, managed pages.
2150 * The object must be locked.
2153 vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
2157 VM_OBJECT_ASSERT_LOCKED(object);
2158 KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0,
2159 ("vm_object_page_noreuse: illegal object %p", object));
2160 if (object->resident_page_count == 0)
2162 p = vm_page_find_least(object, start);
2165 * Here, the variable "p" is either (1) the page with the least pindex
2166 * greater than or equal to the parameter "start" or (2) NULL.
2168 for (; p != NULL && (p->pindex < end || end == 0); p = next) {
2169 next = TAILQ_NEXT(p, listq);
2170 vm_page_deactivate_noreuse(p);
2175 * Populate the specified range of the object with valid pages. Returns
2176 * TRUE if the range is successfully populated and FALSE otherwise.
2178 * Note: This function should be optimized to pass a larger array of
2179 * pages to vm_pager_get_pages() before it is applied to a non-
2180 * OBJT_DEVICE object.
2182 * The object must be locked.
2185 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
2191 VM_OBJECT_ASSERT_WLOCKED(object);
2192 for (pindex = start; pindex < end; pindex++) {
2193 rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL);
2194 if (rv != VM_PAGER_OK)
2198 * Keep "m" busy because a subsequent iteration may unlock
2202 if (pindex > start) {
2203 m = vm_page_lookup(object, start);
2204 while (m != NULL && m->pindex < pindex) {
2206 m = TAILQ_NEXT(m, listq);
2209 return (pindex == end);
2213 * Routine: vm_object_coalesce
2214 * Function: Coalesces two objects backing up adjoining
2215 * regions of memory into a single object.
2217 * returns TRUE if objects were combined.
2219 * NOTE: Only works at the moment if the second object is NULL -
2220 * if it's not, which object do we lock first?
2223 * prev_object First object to coalesce
2224 * prev_offset Offset into prev_object
2225 * prev_size Size of reference to prev_object
2226 * next_size Size of reference to the second object
2227 * reserved Indicator that extension region has
2228 * swap accounted for
2231 * The object must *not* be locked.
2234 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset,
2235 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved)
2237 vm_pindex_t next_pindex;
2239 if (prev_object == NULL)
2241 if ((prev_object->flags & OBJ_ANON) == 0)
2244 VM_OBJECT_WLOCK(prev_object);
2246 * Try to collapse the object first.
2248 vm_object_collapse(prev_object);
2251 * Can't coalesce if: . more than one reference . paged out . shadows
2252 * another object . has a copy elsewhere (any of which mean that the
2253 * pages not mapped to prev_entry may be in use anyway)
2255 if (prev_object->backing_object != NULL) {
2256 VM_OBJECT_WUNLOCK(prev_object);
2260 prev_size >>= PAGE_SHIFT;
2261 next_size >>= PAGE_SHIFT;
2262 next_pindex = OFF_TO_IDX(prev_offset) + prev_size;
2264 if (prev_object->ref_count > 1 &&
2265 prev_object->size != next_pindex &&
2266 (prev_object->flags & OBJ_ONEMAPPING) == 0) {
2267 VM_OBJECT_WUNLOCK(prev_object);
2272 * Account for the charge.
2274 if (prev_object->cred != NULL) {
2277 * If prev_object was charged, then this mapping,
2278 * although not charged now, may become writable
2279 * later. Non-NULL cred in the object would prevent
2280 * swap reservation during enabling of the write
2281 * access, so reserve swap now. Failed reservation
2282 * cause allocation of the separate object for the map
2283 * entry, and swap reservation for this entry is
2284 * managed in appropriate time.
2286 if (!reserved && !swap_reserve_by_cred(ptoa(next_size),
2287 prev_object->cred)) {
2288 VM_OBJECT_WUNLOCK(prev_object);
2291 prev_object->charge += ptoa(next_size);
2295 * Remove any pages that may still be in the object from a previous
2298 if (next_pindex < prev_object->size) {
2299 vm_object_page_remove(prev_object, next_pindex, next_pindex +
2301 if (prev_object->type == OBJT_SWAP)
2302 swap_pager_freespace(prev_object,
2303 next_pindex, next_size);
2305 if (prev_object->cred != NULL) {
2306 KASSERT(prev_object->charge >=
2307 ptoa(prev_object->size - next_pindex),
2308 ("object %p overcharged 1 %jx %jx", prev_object,
2309 (uintmax_t)next_pindex, (uintmax_t)next_size));
2310 prev_object->charge -= ptoa(prev_object->size -
2317 * Extend the object if necessary.
2319 if (next_pindex + next_size > prev_object->size)
2320 prev_object->size = next_pindex + next_size;
2322 VM_OBJECT_WUNLOCK(prev_object);
2327 vm_object_set_writeable_dirty(vm_object_t object)
2330 /* Only set for vnodes & tmpfs */
2331 if (object->type != OBJT_VNODE &&
2332 (object->flags & OBJ_TMPFS_NODE) == 0)
2334 atomic_add_int(&object->generation, 1);
2340 * For each page offset within the specified range of the given object,
2341 * find the highest-level page in the shadow chain and unwire it. A page
2342 * must exist at every page offset, and the highest-level page must be
2346 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length,
2349 vm_object_t tobject, t1object;
2351 vm_pindex_t end_pindex, pindex, tpindex;
2352 int depth, locked_depth;
2354 KASSERT((offset & PAGE_MASK) == 0,
2355 ("vm_object_unwire: offset is not page aligned"));
2356 KASSERT((length & PAGE_MASK) == 0,
2357 ("vm_object_unwire: length is not a multiple of PAGE_SIZE"));
2358 /* The wired count of a fictitious page never changes. */
2359 if ((object->flags & OBJ_FICTITIOUS) != 0)
2361 pindex = OFF_TO_IDX(offset);
2362 end_pindex = pindex + atop(length);
2365 VM_OBJECT_RLOCK(object);
2366 m = vm_page_find_least(object, pindex);
2367 while (pindex < end_pindex) {
2368 if (m == NULL || pindex < m->pindex) {
2370 * The first object in the shadow chain doesn't
2371 * contain a page at the current index. Therefore,
2372 * the page must exist in a backing object.
2379 OFF_TO_IDX(tobject->backing_object_offset);
2380 tobject = tobject->backing_object;
2381 KASSERT(tobject != NULL,
2382 ("vm_object_unwire: missing page"));
2383 if ((tobject->flags & OBJ_FICTITIOUS) != 0)
2386 if (depth == locked_depth) {
2388 VM_OBJECT_RLOCK(tobject);
2390 } while ((tm = vm_page_lookup(tobject, tpindex)) ==
2394 m = TAILQ_NEXT(m, listq);
2396 if (vm_page_trysbusy(tm) == 0) {
2397 for (tobject = object; locked_depth >= 1;
2399 t1object = tobject->backing_object;
2400 if (tm->object != tobject)
2401 VM_OBJECT_RUNLOCK(tobject);
2404 vm_page_busy_sleep(tm, "unwbo", true);
2407 vm_page_unwire(tm, queue);
2408 vm_page_sunbusy(tm);
2412 /* Release the accumulated object locks. */
2413 for (tobject = object; locked_depth >= 1; locked_depth--) {
2414 t1object = tobject->backing_object;
2415 VM_OBJECT_RUNLOCK(tobject);
2421 * Return the vnode for the given object, or NULL if none exists.
2422 * For tmpfs objects, the function may return NULL if there is
2423 * no vnode allocated at the time of the call.
2426 vm_object_vnode(vm_object_t object)
2430 VM_OBJECT_ASSERT_LOCKED(object);
2431 if (object->type == OBJT_VNODE) {
2432 vp = object->handle;
2433 KASSERT(vp != NULL, ("%s: OBJT_VNODE has no vnode", __func__));
2434 } else if (object->type == OBJT_SWAP &&
2435 (object->flags & OBJ_TMPFS) != 0) {
2436 vp = object->un_pager.swp.swp_tmpfs;
2437 KASSERT(vp != NULL, ("%s: OBJT_TMPFS has no vnode", __func__));
2446 * Busy the vm object. This prevents new pages belonging to the object from
2447 * becoming busy. Existing pages persist as busy. Callers are responsible
2448 * for checking page state before proceeding.
2451 vm_object_busy(vm_object_t obj)
2454 VM_OBJECT_ASSERT_LOCKED(obj);
2456 blockcount_acquire(&obj->busy, 1);
2457 /* The fence is required to order loads of page busy. */
2458 atomic_thread_fence_acq_rel();
2462 vm_object_unbusy(vm_object_t obj)
2465 blockcount_release(&obj->busy, 1);
2469 vm_object_busy_wait(vm_object_t obj, const char *wmesg)
2472 VM_OBJECT_ASSERT_UNLOCKED(obj);
2474 (void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM);
2478 * Return the kvme type of the given object.
2479 * If vpp is not NULL, set it to the object's vm_object_vnode() or NULL.
2482 vm_object_kvme_type(vm_object_t object, struct vnode **vpp)
2485 VM_OBJECT_ASSERT_LOCKED(object);
2487 *vpp = vm_object_vnode(object);
2488 switch (object->type) {
2490 return (KVME_TYPE_DEFAULT);
2492 return (KVME_TYPE_VNODE);
2494 if ((object->flags & OBJ_TMPFS_NODE) != 0)
2495 return (KVME_TYPE_VNODE);
2496 return (KVME_TYPE_SWAP);
2498 return (KVME_TYPE_DEVICE);
2500 return (KVME_TYPE_PHYS);
2502 return (KVME_TYPE_DEAD);
2504 return (KVME_TYPE_SG);
2505 case OBJT_MGTDEVICE:
2506 return (KVME_TYPE_MGTDEVICE);
2508 return (KVME_TYPE_UNKNOWN);
2513 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS)
2515 struct kinfo_vmobject *kvo;
2516 char *fullpath, *freepath;
2523 if (req->oldptr == NULL) {
2525 * If an old buffer has not been provided, generate an
2526 * estimate of the space needed for a subsequent call.
2528 mtx_lock(&vm_object_list_mtx);
2530 TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2531 if (obj->type == OBJT_DEAD)
2535 mtx_unlock(&vm_object_list_mtx);
2536 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) *
2540 kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK);
2544 * VM objects are type stable and are never removed from the
2545 * list once added. This allows us to safely read obj->object_list
2546 * after reacquiring the VM object lock.
2548 mtx_lock(&vm_object_list_mtx);
2549 TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2550 if (obj->type == OBJT_DEAD)
2552 VM_OBJECT_RLOCK(obj);
2553 if (obj->type == OBJT_DEAD) {
2554 VM_OBJECT_RUNLOCK(obj);
2557 mtx_unlock(&vm_object_list_mtx);
2558 kvo->kvo_size = ptoa(obj->size);
2559 kvo->kvo_resident = obj->resident_page_count;
2560 kvo->kvo_ref_count = obj->ref_count;
2561 kvo->kvo_shadow_count = obj->shadow_count;
2562 kvo->kvo_memattr = obj->memattr;
2563 kvo->kvo_active = 0;
2564 kvo->kvo_inactive = 0;
2565 TAILQ_FOREACH(m, &obj->memq, listq) {
2567 * A page may belong to the object but be
2568 * dequeued and set to PQ_NONE while the
2569 * object lock is not held. This makes the
2570 * reads of m->queue below racy, and we do not
2571 * count pages set to PQ_NONE. However, this
2572 * sysctl is only meant to give an
2573 * approximation of the system anyway.
2575 if (m->a.queue == PQ_ACTIVE)
2577 else if (m->a.queue == PQ_INACTIVE)
2578 kvo->kvo_inactive++;
2581 kvo->kvo_vn_fileid = 0;
2582 kvo->kvo_vn_fsid = 0;
2583 kvo->kvo_vn_fsid_freebsd11 = 0;
2586 kvo->kvo_type = vm_object_kvme_type(obj, &vp);
2589 VM_OBJECT_RUNLOCK(obj);
2591 vn_fullpath(curthread, vp, &fullpath, &freepath);
2592 vn_lock(vp, LK_SHARED | LK_RETRY);
2593 if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) {
2594 kvo->kvo_vn_fileid = va.va_fileid;
2595 kvo->kvo_vn_fsid = va.va_fsid;
2596 kvo->kvo_vn_fsid_freebsd11 = va.va_fsid;
2602 strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path));
2603 if (freepath != NULL)
2604 free(freepath, M_TEMP);
2606 /* Pack record size down */
2607 kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path)
2608 + strlen(kvo->kvo_path) + 1;
2609 kvo->kvo_structsize = roundup(kvo->kvo_structsize,
2611 error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize);
2612 mtx_lock(&vm_object_list_mtx);
2616 mtx_unlock(&vm_object_list_mtx);
2620 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP |
2621 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject",
2622 "List of VM objects");
2624 #include "opt_ddb.h"
2626 #include <sys/kernel.h>
2628 #include <sys/cons.h>
2630 #include <ddb/ddb.h>
2633 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
2636 vm_map_entry_t tmpe;
2643 VM_MAP_ENTRY_FOREACH(tmpe, map) {
2644 if (_vm_object_in_map(map, object, tmpe)) {
2648 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
2649 tmpm = entry->object.sub_map;
2650 VM_MAP_ENTRY_FOREACH(tmpe, tmpm) {
2651 if (_vm_object_in_map(tmpm, object, tmpe)) {
2655 } else if ((obj = entry->object.vm_object) != NULL) {
2656 for (; obj; obj = obj->backing_object)
2657 if (obj == object) {
2665 vm_object_in_map(vm_object_t object)
2669 /* sx_slock(&allproc_lock); */
2670 FOREACH_PROC_IN_SYSTEM(p) {
2671 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
2673 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
2674 /* sx_sunlock(&allproc_lock); */
2678 /* sx_sunlock(&allproc_lock); */
2679 if (_vm_object_in_map(kernel_map, object, 0))
2684 DB_SHOW_COMMAND(vmochk, vm_object_check)
2689 * make sure that internal objs are in a map somewhere
2690 * and none have zero ref counts.
2692 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2693 if ((object->flags & OBJ_ANON) != 0) {
2694 if (object->ref_count == 0) {
2695 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2696 (long)object->size);
2698 if (!vm_object_in_map(object)) {
2700 "vmochk: internal obj is not in a map: "
2701 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2702 object->ref_count, (u_long)object->size,
2703 (u_long)object->size,
2704 (void *)object->backing_object);
2711 * vm_object_print: [ debug ]
2713 DB_SHOW_COMMAND(object, vm_object_print_static)
2715 /* XXX convert args. */
2716 vm_object_t object = (vm_object_t)addr;
2717 boolean_t full = have_addr;
2721 /* XXX count is an (unused) arg. Avoid shadowing it. */
2722 #define count was_count
2730 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n",
2731 object, (int)object->type, (uintmax_t)object->size,
2732 object->resident_page_count, object->ref_count, object->flags,
2733 object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge);
2734 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
2735 object->shadow_count,
2736 object->backing_object ? object->backing_object->ref_count : 0,
2737 object->backing_object, (uintmax_t)object->backing_object_offset);
2744 TAILQ_FOREACH(p, &object->memq, listq) {
2746 db_iprintf("memory:=");
2747 else if (count == 6) {
2755 db_printf("(off=0x%jx,page=0x%jx)",
2756 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
2766 /* XXX need this non-static entry for calling from vm_map_print. */
2769 /* db_expr_t */ long addr,
2770 boolean_t have_addr,
2771 /* db_expr_t */ long count,
2774 vm_object_print_static(addr, have_addr, count, modif);
2777 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2782 vm_page_t m, prev_m;
2786 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2787 db_printf("new object: %p\n", (void *)object);
2798 TAILQ_FOREACH(m, &object->memq, listq) {
2799 if (m->pindex > 128)
2801 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL &&
2802 prev_m->pindex + 1 != m->pindex) {
2804 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2805 (long)fidx, rcount, (long)pa);
2817 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2822 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2823 (long)fidx, rcount, (long)pa);
2833 pa = VM_PAGE_TO_PHYS(m);
2837 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2838 (long)fidx, rcount, (long)pa);