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>
76 #include <sys/limits.h>
79 #include <sys/mount.h>
80 #include <sys/kernel.h>
81 #include <sys/pctrie.h>
82 #include <sys/sysctl.h>
83 #include <sys/mutex.h>
84 #include <sys/proc.h> /* for curproc, pageproc */
85 #include <sys/refcount.h>
86 #include <sys/socket.h>
87 #include <sys/resourcevar.h>
88 #include <sys/refcount.h>
89 #include <sys/rwlock.h>
91 #include <sys/vnode.h>
92 #include <sys/vmmeter.h>
96 #include <vm/vm_param.h>
98 #include <vm/vm_map.h>
99 #include <vm/vm_object.h>
100 #include <vm/vm_page.h>
101 #include <vm/vm_pageout.h>
102 #include <vm/vm_pager.h>
103 #include <vm/vm_phys.h>
104 #include <vm/vm_pagequeue.h>
105 #include <vm/swap_pager.h>
106 #include <vm/vm_kern.h>
107 #include <vm/vm_extern.h>
108 #include <vm/vm_radix.h>
109 #include <vm/vm_reserv.h>
112 static int old_msync;
113 SYSCTL_INT(_vm, OID_AUTO, old_msync, CTLFLAG_RW, &old_msync, 0,
114 "Use old (insecure) msync behavior");
116 static int vm_object_page_collect_flush(vm_object_t object, vm_page_t p,
117 int pagerflags, int flags, boolean_t *allclean,
119 static boolean_t vm_object_page_remove_write(vm_page_t p, int flags,
120 boolean_t *allclean);
121 static void vm_object_backing_remove(vm_object_t object);
124 * Virtual memory objects maintain the actual data
125 * associated with allocated virtual memory. A given
126 * page of memory exists within exactly one object.
128 * An object is only deallocated when all "references"
129 * are given up. Only one "reference" to a given
130 * region of an object should be writeable.
132 * Associated with each object is a list of all resident
133 * memory pages belonging to that object; this list is
134 * maintained by the "vm_page" module, and locked by the object's
137 * Each object also records a "pager" routine which is
138 * used to retrieve (and store) pages to the proper backing
139 * storage. In addition, objects may be backed by other
140 * objects from which they were virtual-copied.
142 * The only items within the object structure which are
143 * modified after time of creation are:
144 * reference count locked by object's lock
145 * pager routine locked by object's lock
149 struct object_q vm_object_list;
150 struct mtx vm_object_list_mtx; /* lock for object list and count */
152 struct vm_object kernel_object_store;
154 static SYSCTL_NODE(_vm_stats, OID_AUTO, object, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
157 static COUNTER_U64_DEFINE_EARLY(object_collapses);
158 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapses, CTLFLAG_RD,
160 "VM object collapses");
162 static COUNTER_U64_DEFINE_EARLY(object_bypasses);
163 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, bypasses, CTLFLAG_RD,
165 "VM object bypasses");
167 static COUNTER_U64_DEFINE_EARLY(object_collapse_waits);
168 SYSCTL_COUNTER_U64(_vm_stats_object, OID_AUTO, collapse_waits, CTLFLAG_RD,
169 &object_collapse_waits,
170 "Number of sleeps for collapse");
172 static uma_zone_t obj_zone;
174 static int vm_object_zinit(void *mem, int size, int flags);
177 static void vm_object_zdtor(void *mem, int size, void *arg);
180 vm_object_zdtor(void *mem, int size, void *arg)
184 object = (vm_object_t)mem;
185 KASSERT(object->ref_count == 0,
186 ("object %p ref_count = %d", object, object->ref_count));
187 KASSERT(TAILQ_EMPTY(&object->memq),
188 ("object %p has resident pages in its memq", object));
189 KASSERT(vm_radix_is_empty(&object->rtree),
190 ("object %p has resident pages in its trie", object));
191 #if VM_NRESERVLEVEL > 0
192 KASSERT(LIST_EMPTY(&object->rvq),
193 ("object %p has reservations",
196 KASSERT(!vm_object_busied(object),
197 ("object %p busy = %d", object, blockcount_read(&object->busy)));
198 KASSERT(object->resident_page_count == 0,
199 ("object %p resident_page_count = %d",
200 object, object->resident_page_count));
201 KASSERT(object->shadow_count == 0,
202 ("object %p shadow_count = %d",
203 object, object->shadow_count));
204 KASSERT(object->type == OBJT_DEAD,
205 ("object %p has non-dead type %d",
206 object, object->type));
211 vm_object_zinit(void *mem, int size, int flags)
215 object = (vm_object_t)mem;
216 rw_init_flags(&object->lock, "vm object", RW_DUPOK | RW_NEW);
218 /* These are true for any object that has been freed */
219 object->type = OBJT_DEAD;
220 vm_radix_init(&object->rtree);
221 refcount_init(&object->ref_count, 0);
222 blockcount_init(&object->paging_in_progress);
223 blockcount_init(&object->busy);
224 object->resident_page_count = 0;
225 object->shadow_count = 0;
226 object->flags = OBJ_DEAD;
228 mtx_lock(&vm_object_list_mtx);
229 TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
230 mtx_unlock(&vm_object_list_mtx);
235 _vm_object_allocate(objtype_t type, vm_pindex_t size, u_short flags,
236 vm_object_t object, void *handle)
239 TAILQ_INIT(&object->memq);
240 LIST_INIT(&object->shadow_head);
243 object->flags = flags;
244 if ((flags & OBJ_SWAP) != 0)
245 pctrie_init(&object->un_pager.swp.swp_blks);
248 * Ensure that swap_pager_swapoff() iteration over object_list
249 * sees up to date type and pctrie head if it observed
252 atomic_thread_fence_rel();
254 object->pg_color = 0;
256 object->domain.dr_policy = NULL;
257 object->generation = 1;
258 object->cleangeneration = 1;
259 refcount_init(&object->ref_count, 1);
260 object->memattr = VM_MEMATTR_DEFAULT;
263 object->handle = handle;
264 object->backing_object = NULL;
265 object->backing_object_offset = (vm_ooffset_t) 0;
266 #if VM_NRESERVLEVEL > 0
267 LIST_INIT(&object->rvq);
269 umtx_shm_object_init(object);
275 * Initialize the VM objects module.
280 TAILQ_INIT(&vm_object_list);
281 mtx_init(&vm_object_list_mtx, "vm object_list", NULL, MTX_DEF);
283 rw_init(&kernel_object->lock, "kernel vm object");
284 _vm_object_allocate(OBJT_PHYS, atop(VM_MAX_KERNEL_ADDRESS -
285 VM_MIN_KERNEL_ADDRESS), OBJ_UNMANAGED, kernel_object, NULL);
286 #if VM_NRESERVLEVEL > 0
287 kernel_object->flags |= OBJ_COLORED;
288 kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
290 kernel_object->un_pager.phys.ops = &default_phys_pg_ops;
293 * The lock portion of struct vm_object must be type stable due
294 * to vm_pageout_fallback_object_lock locking a vm object
295 * without holding any references to it.
297 * paging_in_progress is valid always. Lockless references to
298 * the objects may acquire pip and then check OBJ_DEAD.
300 obj_zone = uma_zcreate("VM OBJECT", sizeof (struct vm_object), NULL,
306 vm_object_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
312 vm_object_clear_flag(vm_object_t object, u_short bits)
315 VM_OBJECT_ASSERT_WLOCKED(object);
316 object->flags &= ~bits;
320 * Sets the default memory attribute for the specified object. Pages
321 * that are allocated to this object are by default assigned this memory
324 * Presently, this function must be called before any pages are allocated
325 * to the object. In the future, this requirement may be relaxed for
326 * "default" and "swap" objects.
329 vm_object_set_memattr(vm_object_t object, vm_memattr_t memattr)
332 VM_OBJECT_ASSERT_WLOCKED(object);
334 if (object->type == OBJT_DEAD)
335 return (KERN_INVALID_ARGUMENT);
336 if (!TAILQ_EMPTY(&object->memq))
337 return (KERN_FAILURE);
339 object->memattr = memattr;
340 return (KERN_SUCCESS);
344 vm_object_pip_add(vm_object_t object, short i)
348 blockcount_acquire(&object->paging_in_progress, i);
352 vm_object_pip_wakeup(vm_object_t object)
355 vm_object_pip_wakeupn(object, 1);
359 vm_object_pip_wakeupn(vm_object_t object, short i)
363 blockcount_release(&object->paging_in_progress, i);
367 * Atomically drop the object lock and wait for pip to drain. This protects
368 * from sleep/wakeup races due to identity changes. The lock is not re-acquired
372 vm_object_pip_sleep(vm_object_t object, const char *waitid)
375 (void)blockcount_sleep(&object->paging_in_progress, &object->lock,
376 waitid, PVM | PDROP);
380 vm_object_pip_wait(vm_object_t object, const char *waitid)
383 VM_OBJECT_ASSERT_WLOCKED(object);
385 blockcount_wait(&object->paging_in_progress, &object->lock, waitid,
390 vm_object_pip_wait_unlocked(vm_object_t object, const char *waitid)
393 VM_OBJECT_ASSERT_UNLOCKED(object);
395 blockcount_wait(&object->paging_in_progress, NULL, waitid, PVM);
399 * vm_object_allocate:
401 * Returns a new object with the given size.
404 vm_object_allocate(objtype_t type, vm_pindex_t size)
411 panic("vm_object_allocate: can't create OBJT_DEAD");
416 flags = OBJ_COLORED | OBJ_SWAP;
420 flags = OBJ_FICTITIOUS | OBJ_UNMANAGED;
423 flags = OBJ_FICTITIOUS;
426 flags = OBJ_UNMANAGED;
432 panic("vm_object_allocate: type %d is undefined or dynamic",
435 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK);
436 _vm_object_allocate(type, size, flags, object, NULL);
442 vm_object_allocate_dyn(objtype_t dyntype, vm_pindex_t size, u_short flags)
446 MPASS(dyntype >= OBJT_FIRST_DYN /* && dyntype < nitems(pagertab) */);
447 object = (vm_object_t)uma_zalloc(obj_zone, M_WAITOK);
448 _vm_object_allocate(dyntype, size, flags, object, NULL);
454 * vm_object_allocate_anon:
456 * Returns a new default object of the given size and marked as
457 * anonymous memory for special split/collapse handling. Color
458 * to be initialized by the caller.
461 vm_object_allocate_anon(vm_pindex_t size, vm_object_t backing_object,
462 struct ucred *cred, vm_size_t charge)
464 vm_object_t handle, object;
466 if (backing_object == NULL)
468 else if ((backing_object->flags & OBJ_ANON) != 0)
469 handle = backing_object->handle;
471 handle = backing_object;
472 object = uma_zalloc(obj_zone, M_WAITOK);
473 _vm_object_allocate(OBJT_DEFAULT, size, OBJ_ANON | OBJ_ONEMAPPING,
476 object->charge = cred != NULL ? charge : 0;
481 vm_object_reference_vnode(vm_object_t object)
486 * vnode objects need the lock for the first reference
487 * to serialize with vnode_object_deallocate().
489 if (!refcount_acquire_if_gt(&object->ref_count, 0)) {
490 VM_OBJECT_RLOCK(object);
491 old = refcount_acquire(&object->ref_count);
492 if (object->type == OBJT_VNODE && old == 0)
493 vref(object->handle);
494 VM_OBJECT_RUNLOCK(object);
499 * vm_object_reference:
501 * Acquires a reference to the given object.
504 vm_object_reference(vm_object_t object)
510 if (object->type == OBJT_VNODE)
511 vm_object_reference_vnode(object);
513 refcount_acquire(&object->ref_count);
514 KASSERT((object->flags & OBJ_DEAD) == 0,
515 ("vm_object_reference: Referenced dead object."));
519 * vm_object_reference_locked:
521 * Gets another reference to the given object.
523 * The object must be locked.
526 vm_object_reference_locked(vm_object_t object)
530 VM_OBJECT_ASSERT_LOCKED(object);
531 old = refcount_acquire(&object->ref_count);
532 if (object->type == OBJT_VNODE && old == 0)
533 vref(object->handle);
534 KASSERT((object->flags & OBJ_DEAD) == 0,
535 ("vm_object_reference: Referenced dead object."));
539 * Handle deallocating an object of type OBJT_VNODE.
542 vm_object_deallocate_vnode(vm_object_t object)
544 struct vnode *vp = (struct vnode *) object->handle;
547 KASSERT(object->type == OBJT_VNODE,
548 ("vm_object_deallocate_vnode: not a vnode object"));
549 KASSERT(vp != NULL, ("vm_object_deallocate_vnode: missing vp"));
551 /* Object lock to protect handle lookup. */
552 last = refcount_release(&object->ref_count);
553 VM_OBJECT_RUNLOCK(object);
558 if (!umtx_shm_vnobj_persistent)
559 umtx_shm_object_terminated(object);
561 /* vrele may need the vnode lock. */
566 * We dropped a reference on an object and discovered that it had a
567 * single remaining shadow. This is a sibling of the reference we
568 * dropped. Attempt to collapse the sibling and backing object.
571 vm_object_deallocate_anon(vm_object_t backing_object)
575 /* Fetch the final shadow. */
576 object = LIST_FIRST(&backing_object->shadow_head);
577 KASSERT(object != NULL && backing_object->shadow_count == 1,
578 ("vm_object_anon_deallocate: ref_count: %d, shadow_count: %d",
579 backing_object->ref_count, backing_object->shadow_count));
580 KASSERT((object->flags & OBJ_ANON) != 0,
581 ("invalid shadow object %p", object));
583 if (!VM_OBJECT_TRYWLOCK(object)) {
585 * Prevent object from disappearing since we do not have a
588 vm_object_pip_add(object, 1);
589 VM_OBJECT_WUNLOCK(backing_object);
590 VM_OBJECT_WLOCK(object);
591 vm_object_pip_wakeup(object);
593 VM_OBJECT_WUNLOCK(backing_object);
596 * Check for a collapse/terminate race with the last reference holder.
598 if ((object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) != 0 ||
599 !refcount_acquire_if_not_zero(&object->ref_count)) {
600 VM_OBJECT_WUNLOCK(object);
603 backing_object = object->backing_object;
604 if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0)
605 vm_object_collapse(object);
606 VM_OBJECT_WUNLOCK(object);
612 * vm_object_deallocate:
614 * Release a reference to the specified object,
615 * gained either through a vm_object_allocate
616 * or a vm_object_reference call. When all references
617 * are gone, storage associated with this object
618 * may be relinquished.
620 * No object may be locked.
623 vm_object_deallocate(vm_object_t object)
628 while (object != NULL) {
630 * If the reference count goes to 0 we start calling
631 * vm_object_terminate() on the object chain. A ref count
632 * of 1 may be a special case depending on the shadow count
633 * being 0 or 1. These cases require a write lock on the
636 if ((object->flags & OBJ_ANON) == 0)
637 released = refcount_release_if_gt(&object->ref_count, 1);
639 released = refcount_release_if_gt(&object->ref_count, 2);
643 if (object->type == OBJT_VNODE) {
644 VM_OBJECT_RLOCK(object);
645 if (object->type == OBJT_VNODE) {
646 vm_object_deallocate_vnode(object);
649 VM_OBJECT_RUNLOCK(object);
652 VM_OBJECT_WLOCK(object);
653 KASSERT(object->ref_count > 0,
654 ("vm_object_deallocate: object deallocated too many times: %d",
658 * If this is not the final reference to an anonymous
659 * object we may need to collapse the shadow chain.
661 if (!refcount_release(&object->ref_count)) {
662 if (object->ref_count > 1 ||
663 object->shadow_count == 0) {
664 if ((object->flags & OBJ_ANON) != 0 &&
665 object->ref_count == 1)
666 vm_object_set_flag(object,
668 VM_OBJECT_WUNLOCK(object);
672 /* Handle collapsing last ref on anonymous objects. */
673 object = vm_object_deallocate_anon(object);
678 * Handle the final reference to an object. We restart
679 * the loop with the backing object to avoid recursion.
681 umtx_shm_object_terminated(object);
682 temp = object->backing_object;
684 KASSERT(object->type == OBJT_DEFAULT ||
685 object->type == OBJT_SWAP,
686 ("shadowed tmpfs v_object 2 %p", object));
687 vm_object_backing_remove(object);
690 KASSERT((object->flags & OBJ_DEAD) == 0,
691 ("vm_object_deallocate: Terminating dead object."));
692 vm_object_set_flag(object, OBJ_DEAD);
693 vm_object_terminate(object);
699 * vm_object_destroy removes the object from the global object list
700 * and frees the space for the object.
703 vm_object_destroy(vm_object_t object)
707 * Release the allocation charge.
709 if (object->cred != NULL) {
710 swap_release_by_cred(object->charge, object->cred);
712 crfree(object->cred);
717 * Free the space for the object.
719 uma_zfree(obj_zone, object);
723 vm_object_backing_remove_locked(vm_object_t object)
725 vm_object_t backing_object;
727 backing_object = object->backing_object;
728 VM_OBJECT_ASSERT_WLOCKED(object);
729 VM_OBJECT_ASSERT_WLOCKED(backing_object);
731 KASSERT((object->flags & OBJ_COLLAPSING) == 0,
732 ("vm_object_backing_remove: Removing collapsing object."));
734 if ((object->flags & OBJ_SHADOWLIST) != 0) {
735 LIST_REMOVE(object, shadow_list);
736 backing_object->shadow_count--;
737 object->flags &= ~OBJ_SHADOWLIST;
739 object->backing_object = NULL;
743 vm_object_backing_remove(vm_object_t object)
745 vm_object_t backing_object;
747 VM_OBJECT_ASSERT_WLOCKED(object);
749 if ((object->flags & OBJ_SHADOWLIST) != 0) {
750 backing_object = object->backing_object;
751 VM_OBJECT_WLOCK(backing_object);
752 vm_object_backing_remove_locked(object);
753 VM_OBJECT_WUNLOCK(backing_object);
755 object->backing_object = NULL;
759 vm_object_backing_insert_locked(vm_object_t object, vm_object_t backing_object)
762 VM_OBJECT_ASSERT_WLOCKED(object);
764 if ((backing_object->flags & OBJ_ANON) != 0) {
765 VM_OBJECT_ASSERT_WLOCKED(backing_object);
766 LIST_INSERT_HEAD(&backing_object->shadow_head, object,
768 backing_object->shadow_count++;
769 object->flags |= OBJ_SHADOWLIST;
771 object->backing_object = backing_object;
775 vm_object_backing_insert(vm_object_t object, vm_object_t backing_object)
778 VM_OBJECT_ASSERT_WLOCKED(object);
780 if ((backing_object->flags & OBJ_ANON) != 0) {
781 VM_OBJECT_WLOCK(backing_object);
782 vm_object_backing_insert_locked(object, backing_object);
783 VM_OBJECT_WUNLOCK(backing_object);
785 object->backing_object = backing_object;
789 * Insert an object into a backing_object's shadow list with an additional
790 * reference to the backing_object added.
793 vm_object_backing_insert_ref(vm_object_t object, vm_object_t backing_object)
796 VM_OBJECT_ASSERT_WLOCKED(object);
798 if ((backing_object->flags & OBJ_ANON) != 0) {
799 VM_OBJECT_WLOCK(backing_object);
800 KASSERT((backing_object->flags & OBJ_DEAD) == 0,
801 ("shadowing dead anonymous object"));
802 vm_object_reference_locked(backing_object);
803 vm_object_backing_insert_locked(object, backing_object);
804 vm_object_clear_flag(backing_object, OBJ_ONEMAPPING);
805 VM_OBJECT_WUNLOCK(backing_object);
807 vm_object_reference(backing_object);
808 object->backing_object = backing_object;
813 * Transfer a backing reference from backing_object to object.
816 vm_object_backing_transfer(vm_object_t object, vm_object_t backing_object)
818 vm_object_t new_backing_object;
821 * Note that the reference to backing_object->backing_object
822 * moves from within backing_object to within object.
824 vm_object_backing_remove_locked(object);
825 new_backing_object = backing_object->backing_object;
826 if (new_backing_object == NULL)
828 if ((new_backing_object->flags & OBJ_ANON) != 0) {
829 VM_OBJECT_WLOCK(new_backing_object);
830 vm_object_backing_remove_locked(backing_object);
831 vm_object_backing_insert_locked(object, new_backing_object);
832 VM_OBJECT_WUNLOCK(new_backing_object);
834 object->backing_object = new_backing_object;
835 backing_object->backing_object = NULL;
840 * Wait for a concurrent collapse to settle.
843 vm_object_collapse_wait(vm_object_t object)
846 VM_OBJECT_ASSERT_WLOCKED(object);
848 while ((object->flags & OBJ_COLLAPSING) != 0) {
849 vm_object_pip_wait(object, "vmcolwait");
850 counter_u64_add(object_collapse_waits, 1);
855 * Waits for a backing object to clear a pending collapse and returns
856 * it locked if it is an ANON object.
859 vm_object_backing_collapse_wait(vm_object_t object)
861 vm_object_t backing_object;
863 VM_OBJECT_ASSERT_WLOCKED(object);
866 backing_object = object->backing_object;
867 if (backing_object == NULL ||
868 (backing_object->flags & OBJ_ANON) == 0)
870 VM_OBJECT_WLOCK(backing_object);
871 if ((backing_object->flags & (OBJ_DEAD | OBJ_COLLAPSING)) == 0)
873 VM_OBJECT_WUNLOCK(object);
874 vm_object_pip_sleep(backing_object, "vmbckwait");
875 counter_u64_add(object_collapse_waits, 1);
876 VM_OBJECT_WLOCK(object);
878 return (backing_object);
882 * vm_object_terminate_pages removes any remaining pageable pages
883 * from the object and resets the object to an empty state.
886 vm_object_terminate_pages(vm_object_t object)
890 VM_OBJECT_ASSERT_WLOCKED(object);
893 * Free any remaining pageable pages. This also removes them from the
894 * paging queues. However, don't free wired pages, just remove them
895 * from the object. Rather than incrementally removing each page from
896 * the object, the page and object are reset to any empty state.
898 TAILQ_FOREACH_SAFE(p, &object->memq, listq, p_next) {
899 vm_page_assert_unbusied(p);
900 KASSERT(p->object == object &&
901 (p->ref_count & VPRC_OBJREF) != 0,
902 ("vm_object_terminate_pages: page %p is inconsistent", p));
905 if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) {
912 * If the object contained any pages, then reset it to an empty state.
913 * None of the object's fields, including "resident_page_count", were
914 * modified by the preceding loop.
916 if (object->resident_page_count != 0) {
917 vm_radix_reclaim_allnodes(&object->rtree);
918 TAILQ_INIT(&object->memq);
919 object->resident_page_count = 0;
920 if (object->type == OBJT_VNODE)
921 vdrop(object->handle);
926 * vm_object_terminate actually destroys the specified object, freeing
927 * up all previously used resources.
929 * The object must be locked.
930 * This routine may block.
933 vm_object_terminate(vm_object_t object)
936 VM_OBJECT_ASSERT_WLOCKED(object);
937 KASSERT((object->flags & OBJ_DEAD) != 0,
938 ("terminating non-dead obj %p", object));
939 KASSERT((object->flags & OBJ_COLLAPSING) == 0,
940 ("terminating collapsing obj %p", object));
941 KASSERT(object->backing_object == NULL,
942 ("terminating shadow obj %p", object));
945 * Wait for the pageout daemon and other current users to be
946 * done with the object. Note that new paging_in_progress
947 * users can come after this wait, but they must check
948 * OBJ_DEAD flag set (without unlocking the object), and avoid
949 * the object being terminated.
951 vm_object_pip_wait(object, "objtrm");
953 KASSERT(object->ref_count == 0,
954 ("vm_object_terminate: object with references, ref_count=%d",
957 if ((object->flags & OBJ_PG_DTOR) == 0)
958 vm_object_terminate_pages(object);
960 #if VM_NRESERVLEVEL > 0
961 if (__predict_false(!LIST_EMPTY(&object->rvq)))
962 vm_reserv_break_all(object);
965 KASSERT(object->cred == NULL || object->type == OBJT_DEFAULT ||
966 (object->flags & OBJ_SWAP) != 0,
967 ("%s: non-swap obj %p has cred", __func__, object));
970 * Let the pager know object is dead.
972 vm_pager_deallocate(object);
973 VM_OBJECT_WUNLOCK(object);
975 vm_object_destroy(object);
979 * Make the page read-only so that we can clear the object flags. However, if
980 * this is a nosync mmap then the object is likely to stay dirty so do not
981 * mess with the page and do not clear the object flags. Returns TRUE if the
982 * page should be flushed, and FALSE otherwise.
985 vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *allclean)
988 vm_page_assert_busied(p);
991 * If we have been asked to skip nosync pages and this is a
992 * nosync page, skip it. Note that the object flags were not
993 * cleared in this case so we do not have to set them.
995 if ((flags & OBJPC_NOSYNC) != 0 && (p->a.flags & PGA_NOSYNC) != 0) {
999 pmap_remove_write(p);
1000 return (p->dirty != 0);
1005 * vm_object_page_clean
1007 * Clean all dirty pages in the specified range of object. Leaves page
1008 * on whatever queue it is currently on. If NOSYNC is set then do not
1009 * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC),
1010 * leaving the object dirty.
1012 * For swap objects backing tmpfs regular files, do not flush anything,
1013 * but remove write protection on the mapped pages to update mtime through
1016 * When stuffing pages asynchronously, allow clustering. XXX we need a
1017 * synchronous clustering mode implementation.
1019 * Odd semantics: if start == end, we clean everything.
1021 * The object must be locked.
1023 * Returns FALSE if some page from the range was not written, as
1024 * reported by the pager, and TRUE otherwise.
1027 vm_object_page_clean(vm_object_t object, vm_ooffset_t start, vm_ooffset_t end,
1031 vm_pindex_t pi, tend, tstart;
1032 int curgeneration, n, pagerflags;
1033 boolean_t eio, res, allclean;
1035 VM_OBJECT_ASSERT_WLOCKED(object);
1037 if (!vm_object_mightbedirty(object) || object->resident_page_count == 0)
1040 pagerflags = (flags & (OBJPC_SYNC | OBJPC_INVAL)) != 0 ?
1041 VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
1042 pagerflags |= (flags & OBJPC_INVAL) != 0 ? VM_PAGER_PUT_INVAL : 0;
1044 tstart = OFF_TO_IDX(start);
1045 tend = (end == 0) ? object->size : OFF_TO_IDX(end + PAGE_MASK);
1046 allclean = tstart == 0 && tend >= object->size;
1050 curgeneration = object->generation;
1052 for (p = vm_page_find_least(object, tstart); p != NULL; p = np) {
1056 np = TAILQ_NEXT(p, listq);
1057 if (vm_page_none_valid(p))
1059 if (vm_page_busy_acquire(p, VM_ALLOC_WAITFAIL) == 0) {
1060 if (object->generation != curgeneration &&
1061 (flags & OBJPC_SYNC) != 0)
1063 np = vm_page_find_least(object, pi);
1066 if (!vm_object_page_remove_write(p, flags, &allclean)) {
1070 if (object->type == OBJT_VNODE) {
1071 n = vm_object_page_collect_flush(object, p, pagerflags,
1072 flags, &allclean, &eio);
1077 if (object->generation != curgeneration &&
1078 (flags & OBJPC_SYNC) != 0)
1082 * If the VOP_PUTPAGES() did a truncated write, so
1083 * that even the first page of the run is not fully
1084 * written, vm_pageout_flush() returns 0 as the run
1085 * length. Since the condition that caused truncated
1086 * write may be permanent, e.g. exhausted free space,
1087 * accepting n == 0 would cause an infinite loop.
1089 * Forwarding the iterator leaves the unwritten page
1090 * behind, but there is not much we can do there if
1091 * filesystem refuses to write it.
1101 np = vm_page_find_least(object, pi + n);
1104 VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0);
1108 * Leave updating cleangeneration for tmpfs objects to tmpfs
1109 * scan. It needs to update mtime, which happens for other
1110 * filesystems during page writeouts.
1112 if (allclean && object->type == OBJT_VNODE)
1113 object->cleangeneration = curgeneration;
1118 vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int pagerflags,
1119 int flags, boolean_t *allclean, boolean_t *eio)
1121 vm_page_t ma[vm_pageout_page_count], p_first, tp;
1122 int count, i, mreq, runlen;
1124 vm_page_lock_assert(p, MA_NOTOWNED);
1125 vm_page_assert_xbusied(p);
1126 VM_OBJECT_ASSERT_WLOCKED(object);
1131 for (tp = p; count < vm_pageout_page_count; count++) {
1132 tp = vm_page_next(tp);
1133 if (tp == NULL || vm_page_tryxbusy(tp) == 0)
1135 if (!vm_object_page_remove_write(tp, flags, allclean)) {
1136 vm_page_xunbusy(tp);
1141 for (p_first = p; count < vm_pageout_page_count; count++) {
1142 tp = vm_page_prev(p_first);
1143 if (tp == NULL || vm_page_tryxbusy(tp) == 0)
1145 if (!vm_object_page_remove_write(tp, flags, allclean)) {
1146 vm_page_xunbusy(tp);
1153 for (tp = p_first, i = 0; i < count; tp = TAILQ_NEXT(tp, listq), i++)
1156 vm_pageout_flush(ma, count, pagerflags, mreq, &runlen, eio);
1161 * Note that there is absolutely no sense in writing out
1162 * anonymous objects, so we track down the vnode object
1164 * We invalidate (remove) all pages from the address space
1165 * for semantic correctness.
1167 * If the backing object is a device object with unmanaged pages, then any
1168 * mappings to the specified range of pages must be removed before this
1169 * function is called.
1171 * Note: certain anonymous maps, such as MAP_NOSYNC maps,
1172 * may start out with a NULL object.
1175 vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
1176 boolean_t syncio, boolean_t invalidate)
1178 vm_object_t backing_object;
1181 int error, flags, fsync_after;
1188 VM_OBJECT_WLOCK(object);
1189 while ((backing_object = object->backing_object) != NULL) {
1190 VM_OBJECT_WLOCK(backing_object);
1191 offset += object->backing_object_offset;
1192 VM_OBJECT_WUNLOCK(object);
1193 object = backing_object;
1194 if (object->size < OFF_TO_IDX(offset + size))
1195 size = IDX_TO_OFF(object->size) - offset;
1198 * Flush pages if writing is allowed, invalidate them
1199 * if invalidation requested. Pages undergoing I/O
1200 * will be ignored by vm_object_page_remove().
1202 * We cannot lock the vnode and then wait for paging
1203 * to complete without deadlocking against vm_fault.
1204 * Instead we simply call vm_object_page_remove() and
1205 * allow it to block internally on a page-by-page
1206 * basis when it encounters pages undergoing async
1209 if (object->type == OBJT_VNODE &&
1210 vm_object_mightbedirty(object) != 0 &&
1211 ((vp = object->handle)->v_vflag & VV_NOSYNC) == 0) {
1212 VM_OBJECT_WUNLOCK(object);
1213 (void) vn_start_write(vp, &mp, V_WAIT);
1214 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1215 if (syncio && !invalidate && offset == 0 &&
1216 atop(size) == object->size) {
1218 * If syncing the whole mapping of the file,
1219 * it is faster to schedule all the writes in
1220 * async mode, also allowing the clustering,
1221 * and then wait for i/o to complete.
1226 flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
1227 flags |= invalidate ? (OBJPC_SYNC | OBJPC_INVAL) : 0;
1228 fsync_after = FALSE;
1230 VM_OBJECT_WLOCK(object);
1231 res = vm_object_page_clean(object, offset, offset + size,
1233 VM_OBJECT_WUNLOCK(object);
1235 error = VOP_FSYNC(vp, MNT_WAIT, curthread);
1237 vn_finished_write(mp);
1240 VM_OBJECT_WLOCK(object);
1242 if ((object->type == OBJT_VNODE ||
1243 object->type == OBJT_DEVICE) && invalidate) {
1244 if (object->type == OBJT_DEVICE)
1246 * The option OBJPR_NOTMAPPED must be passed here
1247 * because vm_object_page_remove() cannot remove
1248 * unmanaged mappings.
1250 flags = OBJPR_NOTMAPPED;
1254 flags = OBJPR_CLEANONLY;
1255 vm_object_page_remove(object, OFF_TO_IDX(offset),
1256 OFF_TO_IDX(offset + size + PAGE_MASK), flags);
1258 VM_OBJECT_WUNLOCK(object);
1263 * Determine whether the given advice can be applied to the object. Advice is
1264 * not applied to unmanaged pages since they never belong to page queues, and
1265 * since MADV_FREE is destructive, it can apply only to anonymous pages that
1266 * have been mapped at most once.
1269 vm_object_advice_applies(vm_object_t object, int advice)
1272 if ((object->flags & OBJ_UNMANAGED) != 0)
1274 if (advice != MADV_FREE)
1276 return ((object->flags & (OBJ_ONEMAPPING | OBJ_ANON)) ==
1277 (OBJ_ONEMAPPING | OBJ_ANON));
1281 vm_object_madvise_freespace(vm_object_t object, int advice, vm_pindex_t pindex,
1285 if (advice == MADV_FREE)
1286 vm_pager_freespace(object, pindex, size);
1290 * vm_object_madvise:
1292 * Implements the madvise function at the object/page level.
1294 * MADV_WILLNEED (any object)
1296 * Activate the specified pages if they are resident.
1298 * MADV_DONTNEED (any object)
1300 * Deactivate the specified pages if they are resident.
1302 * MADV_FREE (OBJT_DEFAULT/OBJT_SWAP objects,
1303 * OBJ_ONEMAPPING only)
1305 * Deactivate and clean the specified pages if they are
1306 * resident. This permits the process to reuse the pages
1307 * without faulting or the kernel to reclaim the pages
1311 vm_object_madvise(vm_object_t object, vm_pindex_t pindex, vm_pindex_t end,
1314 vm_pindex_t tpindex;
1315 vm_object_t backing_object, tobject;
1322 VM_OBJECT_WLOCK(object);
1323 if (!vm_object_advice_applies(object, advice)) {
1324 VM_OBJECT_WUNLOCK(object);
1327 for (m = vm_page_find_least(object, pindex); pindex < end; pindex++) {
1331 * If the next page isn't resident in the top-level object, we
1332 * need to search the shadow chain. When applying MADV_FREE, we
1333 * take care to release any swap space used to store
1334 * non-resident pages.
1336 if (m == NULL || pindex < m->pindex) {
1338 * Optimize a common case: if the top-level object has
1339 * no backing object, we can skip over the non-resident
1340 * range in constant time.
1342 if (object->backing_object == NULL) {
1343 tpindex = (m != NULL && m->pindex < end) ?
1345 vm_object_madvise_freespace(object, advice,
1346 pindex, tpindex - pindex);
1347 if ((pindex = tpindex) == end)
1354 vm_object_madvise_freespace(tobject, advice,
1357 * Prepare to search the next object in the
1360 backing_object = tobject->backing_object;
1361 if (backing_object == NULL)
1363 VM_OBJECT_WLOCK(backing_object);
1365 OFF_TO_IDX(tobject->backing_object_offset);
1366 if (tobject != object)
1367 VM_OBJECT_WUNLOCK(tobject);
1368 tobject = backing_object;
1369 if (!vm_object_advice_applies(tobject, advice))
1371 } while ((tm = vm_page_lookup(tobject, tpindex)) ==
1376 m = TAILQ_NEXT(m, listq);
1380 * If the page is not in a normal state, skip it. The page
1381 * can not be invalidated while the object lock is held.
1383 if (!vm_page_all_valid(tm) || vm_page_wired(tm))
1385 KASSERT((tm->flags & PG_FICTITIOUS) == 0,
1386 ("vm_object_madvise: page %p is fictitious", tm));
1387 KASSERT((tm->oflags & VPO_UNMANAGED) == 0,
1388 ("vm_object_madvise: page %p is not managed", tm));
1389 if (vm_page_tryxbusy(tm) == 0) {
1390 if (object != tobject)
1391 VM_OBJECT_WUNLOCK(object);
1392 if (advice == MADV_WILLNEED) {
1394 * Reference the page before unlocking and
1395 * sleeping so that the page daemon is less
1396 * likely to reclaim it.
1398 vm_page_aflag_set(tm, PGA_REFERENCED);
1400 if (!vm_page_busy_sleep(tm, "madvpo", 0))
1401 VM_OBJECT_WUNLOCK(tobject);
1404 vm_page_advise(tm, advice);
1405 vm_page_xunbusy(tm);
1406 vm_object_madvise_freespace(tobject, advice, tm->pindex, 1);
1408 if (tobject != object)
1409 VM_OBJECT_WUNLOCK(tobject);
1411 VM_OBJECT_WUNLOCK(object);
1417 * Create a new object which is backed by the
1418 * specified existing object range. The source
1419 * object reference is deallocated.
1421 * The new object and offset into that object
1422 * are returned in the source parameters.
1425 vm_object_shadow(vm_object_t *object, vm_ooffset_t *offset, vm_size_t length,
1426 struct ucred *cred, bool shared)
1434 * Don't create the new object if the old object isn't shared.
1436 * If we hold the only reference we can guarantee that it won't
1437 * increase while we have the map locked. Otherwise the race is
1438 * harmless and we will end up with an extra shadow object that
1439 * will be collapsed later.
1441 if (source != NULL && source->ref_count == 1 &&
1442 (source->flags & OBJ_ANON) != 0)
1446 * Allocate a new object with the given length.
1448 result = vm_object_allocate_anon(atop(length), source, cred, length);
1451 * Store the offset into the source object, and fix up the offset into
1454 result->backing_object_offset = *offset;
1456 if (shared || source != NULL) {
1457 VM_OBJECT_WLOCK(result);
1460 * The new object shadows the source object, adding a
1461 * reference to it. Our caller changes his reference
1462 * to point to the new object, removing a reference to
1463 * the source object. Net result: no change of
1464 * reference count, unless the caller needs to add one
1465 * more reference due to forking a shared map entry.
1468 vm_object_reference_locked(result);
1469 vm_object_clear_flag(result, OBJ_ONEMAPPING);
1473 * Try to optimize the result object's page color when
1474 * shadowing in order to maintain page coloring
1475 * consistency in the combined shadowed object.
1477 if (source != NULL) {
1478 vm_object_backing_insert(result, source);
1479 result->domain = source->domain;
1480 #if VM_NRESERVLEVEL > 0
1481 result->flags |= source->flags & OBJ_COLORED;
1482 result->pg_color = (source->pg_color +
1483 OFF_TO_IDX(*offset)) & ((1 << (VM_NFREEORDER -
1487 VM_OBJECT_WUNLOCK(result);
1491 * Return the new things
1500 * Split the pages in a map entry into a new object. This affords
1501 * easier removal of unused pages, and keeps object inheritance from
1502 * being a negative impact on memory usage.
1505 vm_object_split(vm_map_entry_t entry)
1507 vm_page_t m, m_busy, m_next;
1508 vm_object_t orig_object, new_object, backing_object;
1509 vm_pindex_t idx, offidxstart;
1512 orig_object = entry->object.vm_object;
1513 KASSERT((orig_object->flags & OBJ_ONEMAPPING) != 0,
1514 ("vm_object_split: Splitting object with multiple mappings."));
1515 if ((orig_object->flags & OBJ_ANON) == 0)
1517 if (orig_object->ref_count <= 1)
1519 VM_OBJECT_WUNLOCK(orig_object);
1521 offidxstart = OFF_TO_IDX(entry->offset);
1522 size = atop(entry->end - entry->start);
1525 * If swap_pager_copy() is later called, it will convert new_object
1526 * into a swap object.
1528 new_object = vm_object_allocate_anon(size, orig_object,
1529 orig_object->cred, ptoa(size));
1532 * We must wait for the orig_object to complete any in-progress
1533 * collapse so that the swap blocks are stable below. The
1534 * additional reference on backing_object by new object will
1535 * prevent further collapse operations until split completes.
1537 VM_OBJECT_WLOCK(orig_object);
1538 vm_object_collapse_wait(orig_object);
1541 * At this point, the new object is still private, so the order in
1542 * which the original and new objects are locked does not matter.
1544 VM_OBJECT_WLOCK(new_object);
1545 new_object->domain = orig_object->domain;
1546 backing_object = orig_object->backing_object;
1547 if (backing_object != NULL) {
1548 vm_object_backing_insert_ref(new_object, backing_object);
1549 new_object->backing_object_offset =
1550 orig_object->backing_object_offset + entry->offset;
1552 if (orig_object->cred != NULL) {
1553 crhold(orig_object->cred);
1554 KASSERT(orig_object->charge >= ptoa(size),
1555 ("orig_object->charge < 0"));
1556 orig_object->charge -= ptoa(size);
1560 * Mark the split operation so that swap_pager_getpages() knows
1561 * that the object is in transition.
1563 vm_object_set_flag(orig_object, OBJ_SPLIT);
1569 m = vm_page_find_least(orig_object, offidxstart);
1570 KASSERT(m == NULL || idx <= m->pindex - offidxstart,
1571 ("%s: object %p was repopulated", __func__, orig_object));
1572 for (; m != NULL && (idx = m->pindex - offidxstart) < size;
1574 m_next = TAILQ_NEXT(m, listq);
1577 * We must wait for pending I/O to complete before we can
1580 * We do not have to VM_PROT_NONE the page as mappings should
1581 * not be changed by this operation.
1583 if (vm_page_tryxbusy(m) == 0) {
1584 VM_OBJECT_WUNLOCK(new_object);
1585 if (vm_page_busy_sleep(m, "spltwt", 0))
1586 VM_OBJECT_WLOCK(orig_object);
1587 VM_OBJECT_WLOCK(new_object);
1592 * The page was left invalid. Likely placed there by
1593 * an incomplete fault. Just remove and ignore.
1595 if (vm_page_none_valid(m)) {
1596 if (vm_page_remove(m))
1601 /* vm_page_rename() will dirty the page. */
1602 if (vm_page_rename(m, new_object, idx)) {
1604 VM_OBJECT_WUNLOCK(new_object);
1605 VM_OBJECT_WUNLOCK(orig_object);
1607 VM_OBJECT_WLOCK(orig_object);
1608 VM_OBJECT_WLOCK(new_object);
1612 #if VM_NRESERVLEVEL > 0
1614 * If some of the reservation's allocated pages remain with
1615 * the original object, then transferring the reservation to
1616 * the new object is neither particularly beneficial nor
1617 * particularly harmful as compared to leaving the reservation
1618 * with the original object. If, however, all of the
1619 * reservation's allocated pages are transferred to the new
1620 * object, then transferring the reservation is typically
1621 * beneficial. Determining which of these two cases applies
1622 * would be more costly than unconditionally renaming the
1625 vm_reserv_rename(m, new_object, orig_object, offidxstart);
1629 * orig_object's type may change while sleeping, so keep track
1630 * of the beginning of the busied range.
1632 if (orig_object->type != OBJT_SWAP)
1634 else if (m_busy == NULL)
1637 if ((orig_object->flags & OBJ_SWAP) != 0) {
1639 * swap_pager_copy() can sleep, in which case the orig_object's
1640 * and new_object's locks are released and reacquired.
1642 swap_pager_copy(orig_object, new_object, offidxstart, 0);
1644 TAILQ_FOREACH_FROM(m_busy, &new_object->memq, listq)
1645 vm_page_xunbusy(m_busy);
1647 vm_object_clear_flag(orig_object, OBJ_SPLIT);
1648 VM_OBJECT_WUNLOCK(orig_object);
1649 VM_OBJECT_WUNLOCK(new_object);
1650 entry->object.vm_object = new_object;
1651 entry->offset = 0LL;
1652 vm_object_deallocate(orig_object);
1653 VM_OBJECT_WLOCK(new_object);
1657 vm_object_collapse_scan_wait(vm_object_t object, vm_page_t p)
1659 vm_object_t backing_object;
1661 VM_OBJECT_ASSERT_WLOCKED(object);
1662 backing_object = object->backing_object;
1663 VM_OBJECT_ASSERT_WLOCKED(backing_object);
1665 KASSERT(p == NULL || p->object == object || p->object == backing_object,
1666 ("invalid ownership %p %p %p", p, object, backing_object));
1667 /* The page is only NULL when rename fails. */
1669 VM_OBJECT_WUNLOCK(object);
1670 VM_OBJECT_WUNLOCK(backing_object);
1672 VM_OBJECT_WLOCK(object);
1673 } else if (p->object == object) {
1674 VM_OBJECT_WUNLOCK(backing_object);
1675 if (vm_page_busy_sleep(p, "vmocol", 0))
1676 VM_OBJECT_WLOCK(object);
1678 VM_OBJECT_WUNLOCK(object);
1679 if (!vm_page_busy_sleep(p, "vmocol", 0))
1680 VM_OBJECT_WUNLOCK(backing_object);
1681 VM_OBJECT_WLOCK(object);
1683 VM_OBJECT_WLOCK(backing_object);
1684 return (TAILQ_FIRST(&backing_object->memq));
1688 vm_object_scan_all_shadowed(vm_object_t object)
1690 vm_object_t backing_object;
1692 vm_pindex_t backing_offset_index, new_pindex, pi, ps;
1694 VM_OBJECT_ASSERT_WLOCKED(object);
1695 VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
1697 backing_object = object->backing_object;
1699 if ((backing_object->flags & OBJ_ANON) == 0)
1702 pi = backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1703 p = vm_page_find_least(backing_object, pi);
1704 ps = swap_pager_find_least(backing_object, pi);
1707 * Only check pages inside the parent object's range and
1708 * inside the parent object's mapping of the backing object.
1711 if (p != NULL && p->pindex < pi)
1712 p = TAILQ_NEXT(p, listq);
1714 ps = swap_pager_find_least(backing_object, pi);
1715 if (p == NULL && ps >= backing_object->size)
1720 pi = MIN(p->pindex, ps);
1722 new_pindex = pi - backing_offset_index;
1723 if (new_pindex >= object->size)
1728 * If the backing object page is busy a
1729 * grandparent or older page may still be
1730 * undergoing CoW. It is not safe to collapse
1731 * the backing object until it is quiesced.
1733 if (vm_page_tryxbusy(p) == 0)
1737 * We raced with the fault handler that left
1738 * newly allocated invalid page on the object
1739 * queue and retried.
1741 if (!vm_page_all_valid(p))
1746 * See if the parent has the page or if the parent's object
1747 * pager has the page. If the parent has the page but the page
1748 * is not valid, the parent's object pager must have the page.
1750 * If this fails, the parent does not completely shadow the
1751 * object and we might as well give up now.
1753 pp = vm_page_lookup(object, new_pindex);
1756 * The valid check here is stable due to object lock
1757 * being required to clear valid and initiate paging.
1758 * Busy of p disallows fault handler to validate pp.
1760 if ((pp == NULL || vm_page_none_valid(pp)) &&
1761 !vm_pager_has_page(object, new_pindex, NULL, NULL))
1775 vm_object_collapse_scan(vm_object_t object)
1777 vm_object_t backing_object;
1778 vm_page_t next, p, pp;
1779 vm_pindex_t backing_offset_index, new_pindex;
1781 VM_OBJECT_ASSERT_WLOCKED(object);
1782 VM_OBJECT_ASSERT_WLOCKED(object->backing_object);
1784 backing_object = object->backing_object;
1785 backing_offset_index = OFF_TO_IDX(object->backing_object_offset);
1790 for (p = TAILQ_FIRST(&backing_object->memq); p != NULL; p = next) {
1791 next = TAILQ_NEXT(p, listq);
1792 new_pindex = p->pindex - backing_offset_index;
1795 * Check for busy page
1797 if (vm_page_tryxbusy(p) == 0) {
1798 next = vm_object_collapse_scan_wait(object, p);
1802 KASSERT(object->backing_object == backing_object,
1803 ("vm_object_collapse_scan: backing object mismatch %p != %p",
1804 object->backing_object, backing_object));
1805 KASSERT(p->object == backing_object,
1806 ("vm_object_collapse_scan: object mismatch %p != %p",
1807 p->object, backing_object));
1809 if (p->pindex < backing_offset_index ||
1810 new_pindex >= object->size) {
1811 vm_pager_freespace(backing_object, p->pindex, 1);
1813 KASSERT(!pmap_page_is_mapped(p),
1814 ("freeing mapped page %p", p));
1815 if (vm_page_remove(p))
1820 if (!vm_page_all_valid(p)) {
1821 KASSERT(!pmap_page_is_mapped(p),
1822 ("freeing mapped page %p", p));
1823 if (vm_page_remove(p))
1828 pp = vm_page_lookup(object, new_pindex);
1829 if (pp != NULL && vm_page_tryxbusy(pp) == 0) {
1832 * The page in the parent is busy and possibly not
1833 * (yet) valid. Until its state is finalized by the
1834 * busy bit owner, we can't tell whether it shadows the
1837 next = vm_object_collapse_scan_wait(object, pp);
1841 if (pp != NULL && vm_page_none_valid(pp)) {
1843 * The page was invalid in the parent. Likely placed
1844 * there by an incomplete fault. Just remove and
1845 * ignore. p can replace it.
1847 if (vm_page_remove(pp))
1852 if (pp != NULL || vm_pager_has_page(object, new_pindex, NULL,
1855 * The page already exists in the parent OR swap exists
1856 * for this location in the parent. Leave the parent's
1857 * page alone. Destroy the original page from the
1860 vm_pager_freespace(backing_object, p->pindex, 1);
1861 KASSERT(!pmap_page_is_mapped(p),
1862 ("freeing mapped page %p", p));
1863 if (vm_page_remove(p))
1866 vm_page_xunbusy(pp);
1871 * Page does not exist in parent, rename the page from the
1872 * backing object to the main object.
1874 * If the page was mapped to a process, it can remain mapped
1875 * through the rename. vm_page_rename() will dirty the page.
1877 if (vm_page_rename(p, object, new_pindex)) {
1879 next = vm_object_collapse_scan_wait(object, NULL);
1883 /* Use the old pindex to free the right page. */
1884 vm_pager_freespace(backing_object, new_pindex +
1885 backing_offset_index, 1);
1887 #if VM_NRESERVLEVEL > 0
1889 * Rename the reservation.
1891 vm_reserv_rename(p, object, backing_object,
1892 backing_offset_index);
1900 * vm_object_collapse:
1902 * Collapse an object with the object backing it.
1903 * Pages in the backing object are moved into the
1904 * parent, and the backing object is deallocated.
1907 vm_object_collapse(vm_object_t object)
1909 vm_object_t backing_object, new_backing_object;
1911 VM_OBJECT_ASSERT_WLOCKED(object);
1914 KASSERT((object->flags & (OBJ_DEAD | OBJ_ANON)) == OBJ_ANON,
1915 ("collapsing invalid object"));
1918 * Wait for the backing_object to finish any pending
1919 * collapse so that the caller sees the shortest possible
1922 backing_object = vm_object_backing_collapse_wait(object);
1923 if (backing_object == NULL)
1926 KASSERT(object->ref_count > 0 &&
1927 object->ref_count > object->shadow_count,
1928 ("collapse with invalid ref %d or shadow %d count.",
1929 object->ref_count, object->shadow_count));
1930 KASSERT((backing_object->flags &
1931 (OBJ_COLLAPSING | OBJ_DEAD)) == 0,
1932 ("vm_object_collapse: Backing object already collapsing."));
1933 KASSERT((object->flags & (OBJ_COLLAPSING | OBJ_DEAD)) == 0,
1934 ("vm_object_collapse: object is already collapsing."));
1937 * We know that we can either collapse the backing object if
1938 * the parent is the only reference to it, or (perhaps) have
1939 * the parent bypass the object if the parent happens to shadow
1940 * all the resident pages in the entire backing object.
1942 if (backing_object->ref_count == 1) {
1943 KASSERT(backing_object->shadow_count == 1,
1944 ("vm_object_collapse: shadow_count: %d",
1945 backing_object->shadow_count));
1946 vm_object_pip_add(object, 1);
1947 vm_object_set_flag(object, OBJ_COLLAPSING);
1948 vm_object_pip_add(backing_object, 1);
1949 vm_object_set_flag(backing_object, OBJ_DEAD);
1952 * If there is exactly one reference to the backing
1953 * object, we can collapse it into the parent.
1955 vm_object_collapse_scan(object);
1957 #if VM_NRESERVLEVEL > 0
1959 * Break any reservations from backing_object.
1961 if (__predict_false(!LIST_EMPTY(&backing_object->rvq)))
1962 vm_reserv_break_all(backing_object);
1966 * Move the pager from backing_object to object.
1968 if ((backing_object->flags & OBJ_SWAP) != 0) {
1970 * swap_pager_copy() can sleep, in which case
1971 * the backing_object's and object's locks are
1972 * released and reacquired.
1973 * Since swap_pager_copy() is being asked to
1974 * destroy backing_object, it will change the
1975 * type to OBJT_DEFAULT.
1980 OFF_TO_IDX(object->backing_object_offset), TRUE);
1984 * Object now shadows whatever backing_object did.
1986 vm_object_clear_flag(object, OBJ_COLLAPSING);
1987 vm_object_backing_transfer(object, backing_object);
1988 object->backing_object_offset +=
1989 backing_object->backing_object_offset;
1990 VM_OBJECT_WUNLOCK(object);
1991 vm_object_pip_wakeup(object);
1994 * Discard backing_object.
1996 * Since the backing object has no pages, no pager left,
1997 * and no object references within it, all that is
1998 * necessary is to dispose of it.
2000 KASSERT(backing_object->ref_count == 1, (
2001 "backing_object %p was somehow re-referenced during collapse!",
2003 vm_object_pip_wakeup(backing_object);
2004 (void)refcount_release(&backing_object->ref_count);
2005 vm_object_terminate(backing_object);
2006 counter_u64_add(object_collapses, 1);
2007 VM_OBJECT_WLOCK(object);
2010 * If we do not entirely shadow the backing object,
2011 * there is nothing we can do so we give up.
2013 * The object lock and backing_object lock must not
2014 * be dropped during this sequence.
2016 if (!vm_object_scan_all_shadowed(object)) {
2017 VM_OBJECT_WUNLOCK(backing_object);
2022 * Make the parent shadow the next object in the
2023 * chain. Deallocating backing_object will not remove
2024 * it, since its reference count is at least 2.
2026 vm_object_backing_remove_locked(object);
2027 new_backing_object = backing_object->backing_object;
2028 if (new_backing_object != NULL) {
2029 vm_object_backing_insert_ref(object,
2030 new_backing_object);
2031 object->backing_object_offset +=
2032 backing_object->backing_object_offset;
2036 * Drop the reference count on backing_object. Since
2037 * its ref_count was at least 2, it will not vanish.
2039 (void)refcount_release(&backing_object->ref_count);
2040 KASSERT(backing_object->ref_count >= 1, (
2041 "backing_object %p was somehow dereferenced during collapse!",
2043 VM_OBJECT_WUNLOCK(backing_object);
2044 counter_u64_add(object_bypasses, 1);
2048 * Try again with this object's new backing object.
2054 * vm_object_page_remove:
2056 * For the given object, either frees or invalidates each of the
2057 * specified pages. In general, a page is freed. However, if a page is
2058 * wired for any reason other than the existence of a managed, wired
2059 * mapping, then it may be invalidated but not removed from the object.
2060 * Pages are specified by the given range ["start", "end") and the option
2061 * OBJPR_CLEANONLY. As a special case, if "end" is zero, then the range
2062 * extends from "start" to the end of the object. If the option
2063 * OBJPR_CLEANONLY is specified, then only the non-dirty pages within the
2064 * specified range are affected. If the option OBJPR_NOTMAPPED is
2065 * specified, then the pages within the specified range must have no
2066 * mappings. Otherwise, if this option is not specified, any mappings to
2067 * the specified pages are removed before the pages are freed or
2070 * In general, this operation should only be performed on objects that
2071 * contain managed pages. There are, however, two exceptions. First, it
2072 * is performed on the kernel and kmem objects by vm_map_entry_delete().
2073 * Second, it is used by msync(..., MS_INVALIDATE) to invalidate device-
2074 * backed pages. In both of these cases, the option OBJPR_CLEANONLY must
2075 * not be specified and the option OBJPR_NOTMAPPED must be specified.
2077 * The object must be locked.
2080 vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
2085 VM_OBJECT_ASSERT_WLOCKED(object);
2086 KASSERT((object->flags & OBJ_UNMANAGED) == 0 ||
2087 (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
2088 ("vm_object_page_remove: illegal options for object %p", object));
2089 if (object->resident_page_count == 0)
2091 vm_object_pip_add(object, 1);
2093 p = vm_page_find_least(object, start);
2096 * Here, the variable "p" is either (1) the page with the least pindex
2097 * greater than or equal to the parameter "start" or (2) NULL.
2099 for (; p != NULL && (p->pindex < end || end == 0); p = next) {
2100 next = TAILQ_NEXT(p, listq);
2103 * Skip invalid pages if asked to do so. Try to avoid acquiring
2104 * the busy lock, as some consumers rely on this to avoid
2107 * A thread may concurrently transition the page from invalid to
2108 * valid using only the busy lock, so the result of this check
2109 * is immediately stale. It is up to consumers to handle this,
2110 * for instance by ensuring that all invalid->valid transitions
2111 * happen with a mutex held, as may be possible for a
2114 if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p))
2118 * If the page is wired for any reason besides the existence
2119 * of managed, wired mappings, then it cannot be freed. For
2120 * example, fictitious pages, which represent device memory,
2121 * are inherently wired and cannot be freed. They can,
2122 * however, be invalidated if the option OBJPR_CLEANONLY is
2125 if (vm_page_tryxbusy(p) == 0) {
2126 if (vm_page_busy_sleep(p, "vmopar", 0))
2127 VM_OBJECT_WLOCK(object);
2130 if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) {
2134 if (vm_page_wired(p)) {
2136 if ((options & OBJPR_NOTMAPPED) == 0 &&
2137 object->ref_count != 0)
2139 if ((options & OBJPR_CLEANONLY) == 0) {
2146 KASSERT((p->flags & PG_FICTITIOUS) == 0,
2147 ("vm_object_page_remove: page %p is fictitious", p));
2148 if ((options & OBJPR_CLEANONLY) != 0 &&
2149 !vm_page_none_valid(p)) {
2150 if ((options & OBJPR_NOTMAPPED) == 0 &&
2151 object->ref_count != 0 &&
2152 !vm_page_try_remove_write(p))
2154 if (p->dirty != 0) {
2159 if ((options & OBJPR_NOTMAPPED) == 0 &&
2160 object->ref_count != 0 && !vm_page_try_remove_all(p))
2164 vm_object_pip_wakeup(object);
2166 vm_pager_freespace(object, start, (end == 0 ? object->size : end) -
2171 * vm_object_page_noreuse:
2173 * For the given object, attempt to move the specified pages to
2174 * the head of the inactive queue. This bypasses regular LRU
2175 * operation and allows the pages to be reused quickly under memory
2176 * pressure. If a page is wired for any reason, then it will not
2177 * be queued. Pages are specified by the range ["start", "end").
2178 * As a special case, if "end" is zero, then the range extends from
2179 * "start" to the end of the object.
2181 * This operation should only be performed on objects that
2182 * contain non-fictitious, managed pages.
2184 * The object must be locked.
2187 vm_object_page_noreuse(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
2191 VM_OBJECT_ASSERT_LOCKED(object);
2192 KASSERT((object->flags & (OBJ_FICTITIOUS | OBJ_UNMANAGED)) == 0,
2193 ("vm_object_page_noreuse: illegal object %p", object));
2194 if (object->resident_page_count == 0)
2196 p = vm_page_find_least(object, start);
2199 * Here, the variable "p" is either (1) the page with the least pindex
2200 * greater than or equal to the parameter "start" or (2) NULL.
2202 for (; p != NULL && (p->pindex < end || end == 0); p = next) {
2203 next = TAILQ_NEXT(p, listq);
2204 vm_page_deactivate_noreuse(p);
2209 * Populate the specified range of the object with valid pages. Returns
2210 * TRUE if the range is successfully populated and FALSE otherwise.
2212 * Note: This function should be optimized to pass a larger array of
2213 * pages to vm_pager_get_pages() before it is applied to a non-
2214 * OBJT_DEVICE object.
2216 * The object must be locked.
2219 vm_object_populate(vm_object_t object, vm_pindex_t start, vm_pindex_t end)
2225 VM_OBJECT_ASSERT_WLOCKED(object);
2226 for (pindex = start; pindex < end; pindex++) {
2227 rv = vm_page_grab_valid(&m, object, pindex, VM_ALLOC_NORMAL);
2228 if (rv != VM_PAGER_OK)
2232 * Keep "m" busy because a subsequent iteration may unlock
2236 if (pindex > start) {
2237 m = vm_page_lookup(object, start);
2238 while (m != NULL && m->pindex < pindex) {
2240 m = TAILQ_NEXT(m, listq);
2243 return (pindex == end);
2247 * Routine: vm_object_coalesce
2248 * Function: Coalesces two objects backing up adjoining
2249 * regions of memory into a single object.
2251 * returns TRUE if objects were combined.
2253 * NOTE: Only works at the moment if the second object is NULL -
2254 * if it's not, which object do we lock first?
2257 * prev_object First object to coalesce
2258 * prev_offset Offset into prev_object
2259 * prev_size Size of reference to prev_object
2260 * next_size Size of reference to the second object
2261 * reserved Indicator that extension region has
2262 * swap accounted for
2265 * The object must *not* be locked.
2268 vm_object_coalesce(vm_object_t prev_object, vm_ooffset_t prev_offset,
2269 vm_size_t prev_size, vm_size_t next_size, boolean_t reserved)
2271 vm_pindex_t next_pindex;
2273 if (prev_object == NULL)
2275 if ((prev_object->flags & OBJ_ANON) == 0)
2278 VM_OBJECT_WLOCK(prev_object);
2280 * Try to collapse the object first.
2282 vm_object_collapse(prev_object);
2285 * Can't coalesce if: . more than one reference . paged out . shadows
2286 * another object . has a copy elsewhere (any of which mean that the
2287 * pages not mapped to prev_entry may be in use anyway)
2289 if (prev_object->backing_object != NULL) {
2290 VM_OBJECT_WUNLOCK(prev_object);
2294 prev_size >>= PAGE_SHIFT;
2295 next_size >>= PAGE_SHIFT;
2296 next_pindex = OFF_TO_IDX(prev_offset) + prev_size;
2298 if (prev_object->ref_count > 1 &&
2299 prev_object->size != next_pindex &&
2300 (prev_object->flags & OBJ_ONEMAPPING) == 0) {
2301 VM_OBJECT_WUNLOCK(prev_object);
2306 * Account for the charge.
2308 if (prev_object->cred != NULL) {
2310 * If prev_object was charged, then this mapping,
2311 * although not charged now, may become writable
2312 * later. Non-NULL cred in the object would prevent
2313 * swap reservation during enabling of the write
2314 * access, so reserve swap now. Failed reservation
2315 * cause allocation of the separate object for the map
2316 * entry, and swap reservation for this entry is
2317 * managed in appropriate time.
2319 if (!reserved && !swap_reserve_by_cred(ptoa(next_size),
2320 prev_object->cred)) {
2321 VM_OBJECT_WUNLOCK(prev_object);
2324 prev_object->charge += ptoa(next_size);
2328 * Remove any pages that may still be in the object from a previous
2331 if (next_pindex < prev_object->size) {
2332 vm_object_page_remove(prev_object, next_pindex, next_pindex +
2335 if (prev_object->cred != NULL) {
2336 KASSERT(prev_object->charge >=
2337 ptoa(prev_object->size - next_pindex),
2338 ("object %p overcharged 1 %jx %jx", prev_object,
2339 (uintmax_t)next_pindex, (uintmax_t)next_size));
2340 prev_object->charge -= ptoa(prev_object->size -
2347 * Extend the object if necessary.
2349 if (next_pindex + next_size > prev_object->size)
2350 prev_object->size = next_pindex + next_size;
2352 VM_OBJECT_WUNLOCK(prev_object);
2357 vm_object_set_writeable_dirty_(vm_object_t object)
2359 atomic_add_int(&object->generation, 1);
2363 vm_object_mightbedirty_(vm_object_t object)
2365 return (object->generation != object->cleangeneration);
2371 * For each page offset within the specified range of the given object,
2372 * find the highest-level page in the shadow chain and unwire it. A page
2373 * must exist at every page offset, and the highest-level page must be
2377 vm_object_unwire(vm_object_t object, vm_ooffset_t offset, vm_size_t length,
2380 vm_object_t tobject, t1object;
2382 vm_pindex_t end_pindex, pindex, tpindex;
2383 int depth, locked_depth;
2385 KASSERT((offset & PAGE_MASK) == 0,
2386 ("vm_object_unwire: offset is not page aligned"));
2387 KASSERT((length & PAGE_MASK) == 0,
2388 ("vm_object_unwire: length is not a multiple of PAGE_SIZE"));
2389 /* The wired count of a fictitious page never changes. */
2390 if ((object->flags & OBJ_FICTITIOUS) != 0)
2392 pindex = OFF_TO_IDX(offset);
2393 end_pindex = pindex + atop(length);
2396 VM_OBJECT_RLOCK(object);
2397 m = vm_page_find_least(object, pindex);
2398 while (pindex < end_pindex) {
2399 if (m == NULL || pindex < m->pindex) {
2401 * The first object in the shadow chain doesn't
2402 * contain a page at the current index. Therefore,
2403 * the page must exist in a backing object.
2410 OFF_TO_IDX(tobject->backing_object_offset);
2411 tobject = tobject->backing_object;
2412 KASSERT(tobject != NULL,
2413 ("vm_object_unwire: missing page"));
2414 if ((tobject->flags & OBJ_FICTITIOUS) != 0)
2417 if (depth == locked_depth) {
2419 VM_OBJECT_RLOCK(tobject);
2421 } while ((tm = vm_page_lookup(tobject, tpindex)) ==
2425 m = TAILQ_NEXT(m, listq);
2427 if (vm_page_trysbusy(tm) == 0) {
2428 for (tobject = object; locked_depth >= 1;
2430 t1object = tobject->backing_object;
2431 if (tm->object != tobject)
2432 VM_OBJECT_RUNLOCK(tobject);
2435 tobject = tm->object;
2436 if (!vm_page_busy_sleep(tm, "unwbo",
2437 VM_ALLOC_IGN_SBUSY))
2438 VM_OBJECT_RUNLOCK(tobject);
2441 vm_page_unwire(tm, queue);
2442 vm_page_sunbusy(tm);
2446 /* Release the accumulated object locks. */
2447 for (tobject = object; locked_depth >= 1; locked_depth--) {
2448 t1object = tobject->backing_object;
2449 VM_OBJECT_RUNLOCK(tobject);
2455 * Return the vnode for the given object, or NULL if none exists.
2456 * For tmpfs objects, the function may return NULL if there is
2457 * no vnode allocated at the time of the call.
2460 vm_object_vnode(vm_object_t object)
2464 VM_OBJECT_ASSERT_LOCKED(object);
2465 vm_pager_getvp(object, &vp, NULL);
2470 * Busy the vm object. This prevents new pages belonging to the object from
2471 * becoming busy. Existing pages persist as busy. Callers are responsible
2472 * for checking page state before proceeding.
2475 vm_object_busy(vm_object_t obj)
2478 VM_OBJECT_ASSERT_LOCKED(obj);
2480 blockcount_acquire(&obj->busy, 1);
2481 /* The fence is required to order loads of page busy. */
2482 atomic_thread_fence_acq_rel();
2486 vm_object_unbusy(vm_object_t obj)
2489 blockcount_release(&obj->busy, 1);
2493 vm_object_busy_wait(vm_object_t obj, const char *wmesg)
2496 VM_OBJECT_ASSERT_UNLOCKED(obj);
2498 (void)blockcount_sleep(&obj->busy, NULL, wmesg, PVM);
2502 vm_object_list_handler(struct sysctl_req *req, bool swap_only)
2504 struct kinfo_vmobject *kvo;
2505 char *fullpath, *freepath;
2513 if (req->oldptr == NULL) {
2515 * If an old buffer has not been provided, generate an
2516 * estimate of the space needed for a subsequent call.
2518 mtx_lock(&vm_object_list_mtx);
2520 TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2521 if (obj->type == OBJT_DEAD)
2525 mtx_unlock(&vm_object_list_mtx);
2526 return (SYSCTL_OUT(req, NULL, sizeof(struct kinfo_vmobject) *
2530 kvo = malloc(sizeof(*kvo), M_TEMP, M_WAITOK);
2534 * VM objects are type stable and are never removed from the
2535 * list once added. This allows us to safely read obj->object_list
2536 * after reacquiring the VM object lock.
2538 mtx_lock(&vm_object_list_mtx);
2539 TAILQ_FOREACH(obj, &vm_object_list, object_list) {
2540 if (obj->type == OBJT_DEAD ||
2541 (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0))
2543 VM_OBJECT_RLOCK(obj);
2544 if (obj->type == OBJT_DEAD ||
2545 (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) {
2546 VM_OBJECT_RUNLOCK(obj);
2549 mtx_unlock(&vm_object_list_mtx);
2550 kvo->kvo_size = ptoa(obj->size);
2551 kvo->kvo_resident = obj->resident_page_count;
2552 kvo->kvo_ref_count = obj->ref_count;
2553 kvo->kvo_shadow_count = obj->shadow_count;
2554 kvo->kvo_memattr = obj->memattr;
2555 kvo->kvo_active = 0;
2556 kvo->kvo_inactive = 0;
2558 TAILQ_FOREACH(m, &obj->memq, listq) {
2560 * A page may belong to the object but be
2561 * dequeued and set to PQ_NONE while the
2562 * object lock is not held. This makes the
2563 * reads of m->queue below racy, and we do not
2564 * count pages set to PQ_NONE. However, this
2565 * sysctl is only meant to give an
2566 * approximation of the system anyway.
2568 if (m->a.queue == PQ_ACTIVE)
2570 else if (m->a.queue == PQ_INACTIVE)
2571 kvo->kvo_inactive++;
2575 kvo->kvo_vn_fileid = 0;
2576 kvo->kvo_vn_fsid = 0;
2577 kvo->kvo_vn_fsid_freebsd11 = 0;
2581 kvo->kvo_type = vm_object_kvme_type(obj, swap_only ? NULL : &vp);
2584 } else if ((obj->flags & OBJ_ANON) != 0) {
2585 MPASS(kvo->kvo_type == KVME_TYPE_DEFAULT ||
2586 kvo->kvo_type == KVME_TYPE_SWAP);
2587 kvo->kvo_me = (uintptr_t)obj;
2588 /* tmpfs objs are reported as vnodes */
2589 kvo->kvo_backing_obj = (uintptr_t)obj->backing_object;
2590 sp = swap_pager_swapped_pages(obj);
2591 kvo->kvo_swapped = sp > UINT32_MAX ? UINT32_MAX : sp;
2593 VM_OBJECT_RUNLOCK(obj);
2595 vn_fullpath(vp, &fullpath, &freepath);
2596 vn_lock(vp, LK_SHARED | LK_RETRY);
2597 if (VOP_GETATTR(vp, &va, curthread->td_ucred) == 0) {
2598 kvo->kvo_vn_fileid = va.va_fileid;
2599 kvo->kvo_vn_fsid = va.va_fsid;
2600 kvo->kvo_vn_fsid_freebsd11 = va.va_fsid;
2606 strlcpy(kvo->kvo_path, fullpath, sizeof(kvo->kvo_path));
2607 if (freepath != NULL)
2608 free(freepath, M_TEMP);
2610 /* Pack record size down */
2611 kvo->kvo_structsize = offsetof(struct kinfo_vmobject, kvo_path)
2612 + strlen(kvo->kvo_path) + 1;
2613 kvo->kvo_structsize = roundup(kvo->kvo_structsize,
2615 error = SYSCTL_OUT(req, kvo, kvo->kvo_structsize);
2617 mtx_lock(&vm_object_list_mtx);
2621 mtx_unlock(&vm_object_list_mtx);
2627 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS)
2629 return (vm_object_list_handler(req, false));
2632 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP |
2633 CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject",
2634 "List of VM objects");
2637 sysctl_vm_object_list_swap(SYSCTL_HANDLER_ARGS)
2639 return (vm_object_list_handler(req, true));
2643 * This sysctl returns list of the anonymous or swap objects. Intent
2644 * is to provide stripped optimized list useful to analyze swap use.
2645 * Since technically non-swap (default) objects participate in the
2646 * shadow chains, and are converted to swap type as needed by swap
2647 * pager, we must report them.
2649 SYSCTL_PROC(_vm, OID_AUTO, swap_objects,
2650 CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, NULL, 0,
2651 sysctl_vm_object_list_swap, "S,kinfo_vmobject",
2652 "List of swap VM objects");
2654 #include "opt_ddb.h"
2656 #include <sys/kernel.h>
2658 #include <sys/cons.h>
2660 #include <ddb/ddb.h>
2663 _vm_object_in_map(vm_map_t map, vm_object_t object, vm_map_entry_t entry)
2666 vm_map_entry_t tmpe;
2673 VM_MAP_ENTRY_FOREACH(tmpe, map) {
2674 if (_vm_object_in_map(map, object, tmpe)) {
2678 } else if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
2679 tmpm = entry->object.sub_map;
2680 VM_MAP_ENTRY_FOREACH(tmpe, tmpm) {
2681 if (_vm_object_in_map(tmpm, object, tmpe)) {
2685 } else if ((obj = entry->object.vm_object) != NULL) {
2686 for (; obj; obj = obj->backing_object)
2687 if (obj == object) {
2695 vm_object_in_map(vm_object_t object)
2699 /* sx_slock(&allproc_lock); */
2700 FOREACH_PROC_IN_SYSTEM(p) {
2701 if (!p->p_vmspace /* || (p->p_flag & (P_SYSTEM|P_WEXIT)) */)
2703 if (_vm_object_in_map(&p->p_vmspace->vm_map, object, 0)) {
2704 /* sx_sunlock(&allproc_lock); */
2708 /* sx_sunlock(&allproc_lock); */
2709 if (_vm_object_in_map(kernel_map, object, 0))
2714 DB_SHOW_COMMAND(vmochk, vm_object_check)
2719 * make sure that internal objs are in a map somewhere
2720 * and none have zero ref counts.
2722 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2723 if ((object->flags & OBJ_ANON) != 0) {
2724 if (object->ref_count == 0) {
2725 db_printf("vmochk: internal obj has zero ref count: %ld\n",
2726 (long)object->size);
2728 if (!vm_object_in_map(object)) {
2730 "vmochk: internal obj is not in a map: "
2731 "ref: %d, size: %lu: 0x%lx, backing_object: %p\n",
2732 object->ref_count, (u_long)object->size,
2733 (u_long)object->size,
2734 (void *)object->backing_object);
2743 * vm_object_print: [ debug ]
2745 DB_SHOW_COMMAND(object, vm_object_print_static)
2747 /* XXX convert args. */
2748 vm_object_t object = (vm_object_t)addr;
2749 boolean_t full = have_addr;
2753 /* XXX count is an (unused) arg. Avoid shadowing it. */
2754 #define count was_count
2762 "Object %p: type=%d, size=0x%jx, res=%d, ref=%d, flags=0x%x ruid %d charge %jx\n",
2763 object, (int)object->type, (uintmax_t)object->size,
2764 object->resident_page_count, object->ref_count, object->flags,
2765 object->cred ? object->cred->cr_ruid : -1, (uintmax_t)object->charge);
2766 db_iprintf(" sref=%d, backing_object(%d)=(%p)+0x%jx\n",
2767 object->shadow_count,
2768 object->backing_object ? object->backing_object->ref_count : 0,
2769 object->backing_object, (uintmax_t)object->backing_object_offset);
2776 TAILQ_FOREACH(p, &object->memq, listq) {
2778 db_iprintf("memory:=");
2779 else if (count == 6) {
2787 db_printf("(off=0x%jx,page=0x%jx)",
2788 (uintmax_t)p->pindex, (uintmax_t)VM_PAGE_TO_PHYS(p));
2801 /* XXX need this non-static entry for calling from vm_map_print. */
2804 /* db_expr_t */ long addr,
2805 boolean_t have_addr,
2806 /* db_expr_t */ long count,
2809 vm_object_print_static(addr, have_addr, count, modif);
2812 DB_SHOW_COMMAND(vmopag, vm_object_print_pages)
2817 vm_page_t m, prev_m;
2821 TAILQ_FOREACH(object, &vm_object_list, object_list) {
2822 db_printf("new object: %p\n", (void *)object);
2833 TAILQ_FOREACH(m, &object->memq, listq) {
2834 if (m->pindex > 128)
2836 if ((prev_m = TAILQ_PREV(m, pglist, listq)) != NULL &&
2837 prev_m->pindex + 1 != m->pindex) {
2839 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2840 (long)fidx, rcount, (long)pa);
2852 (VM_PAGE_TO_PHYS(m) == pa + rcount * PAGE_SIZE)) {
2857 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2858 (long)fidx, rcount, (long)pa);
2868 pa = VM_PAGE_TO_PHYS(m);
2872 db_printf(" index(%ld)run(%d)pa(0x%lx)\n",
2873 (long)fidx, rcount, (long)pa);