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.
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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
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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_page.h 8.2 (Berkeley) 12/13/93
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.
66 * Resident memory system definitions.
75 * Management of resident (logical) pages.
77 * A small structure is kept for each resident
78 * page, indexed by page number. Each structure
79 * is an element of several collections:
81 * A radix tree used to quickly
82 * perform object/offset lookups
84 * A list of all pages for a given object,
85 * so they can be quickly deactivated at
86 * time of deallocation.
88 * An ordered list of pages due for pageout.
90 * In addition, the structure contains the object
91 * and offset to which this page belongs (for pageout),
92 * and sundry status bits.
94 * In general, operations on this structure's mutable fields are
95 * synchronized using either one of or a combination of the lock on the
96 * object that the page belongs to (O), the page lock (P),
97 * the per-domain lock for the free queues (F), or the page's queue
98 * lock (Q). The physical address of a page is used to select its page
99 * lock from a pool. The queue lock for a page depends on the value of
100 * its queue field and described in detail below. If a field is
101 * annotated below with two of these locks, then holding either lock is
102 * sufficient for read access, but both locks are required for write
103 * access. An annotation of (C) indicates that the field is immutable.
105 * In contrast, the synchronization of accesses to the page's
106 * dirty field is machine dependent (M). In the
107 * machine-independent layer, the lock on the object that the
108 * page belongs to must be held in order to operate on the field.
109 * However, the pmap layer is permitted to set all bits within
110 * the field without holding that lock. If the underlying
111 * architecture does not support atomic read-modify-write
112 * operations on the field's type, then the machine-independent
113 * layer uses a 32-bit atomic on the aligned 32-bit word that
114 * contains the dirty field. In the machine-independent layer,
115 * the implementation of read-modify-write operations on the
116 * field is encapsulated in vm_page_clear_dirty_mask().
118 * The page structure contains two counters which prevent page reuse.
119 * Both counters are protected by the page lock (P). The hold
120 * counter counts transient references obtained via a pmap lookup, and
121 * is also used to prevent page reclamation in situations where it is
122 * undesirable to block other accesses to the page. The wire counter
123 * is used to implement mlock(2) and is non-zero for pages containing
124 * kernel memory. Pages that are wired or held will not be reclaimed
125 * or laundered by the page daemon, but are treated differently during
126 * a page queue scan: held pages remain at their position in the queue,
127 * while wired pages are removed from the queue and must later be
128 * re-enqueued appropriately by the unwiring thread. It is legal to
129 * call vm_page_free() on a held page; doing so causes it to be removed
130 * from its object and page queue, and the page is released to the
131 * allocator once the last hold reference is dropped. In contrast,
132 * wired pages may not be freed.
134 * In some pmap implementations, the wire count of a page table page is
135 * used to track the number of populated entries.
137 * The busy lock is an embedded reader-writer lock which protects the
138 * page's contents and identity (i.e., its <object, pindex> tuple) and
139 * interlocks with the object lock (O). In particular, a page may be
140 * busied or unbusied only with the object write lock held. To avoid
141 * bloating the page structure, the busy lock lacks some of the
142 * features available to the kernel's general-purpose synchronization
143 * primitives. As a result, busy lock ordering rules are not verified,
144 * lock recursion is not detected, and an attempt to xbusy a busy page
145 * or sbusy an xbusy page results will trigger a panic rather than
146 * causing the thread to block. vm_page_sleep_if_busy() can be used to
147 * sleep until the page's busy state changes, after which the caller
148 * must re-lookup the page and re-evaluate its state.
150 * The queue field is the index of the page queue containing the page,
151 * or PQ_NONE if the page is not enqueued. The queue lock of a page is
152 * the page queue lock corresponding to the page queue index, or the
153 * page lock (P) for the page if it is not enqueued. To modify the
154 * queue field, the queue lock for the old value of the field must be
155 * held. There is one exception to this rule: the page daemon may
156 * transition the queue field from PQ_INACTIVE to PQ_NONE immediately
157 * prior to freeing a page during an inactive queue scan. At that
158 * point the page has already been physically dequeued and no other
159 * references to that vm_page structure exist.
161 * To avoid contention on page queue locks, page queue operations
162 * (enqueue, dequeue, requeue) are batched using per-CPU queues. A
163 * deferred operation is requested by inserting an entry into a batch
164 * queue; the entry is simply a pointer to the page, and the request
165 * type is encoded in the page's aflags field using the values in
166 * PGA_QUEUE_STATE_MASK. The type-stability of struct vm_pages is
167 * crucial to this scheme since the processing of entries in a given
168 * batch queue may be deferred indefinitely. In particular, a page may
169 * be freed before its pending batch queue entries have been processed.
170 * The page lock (P) must be held to schedule a batched queue
171 * operation, and the page queue lock must be held in order to process
172 * batch queue entries for the page queue. There is one exception to
173 * this rule: the thread freeing a page may schedule a dequeue without
174 * holding the page lock. In this scenario the only other thread which
175 * may hold a reference to the page is the page daemon, which is
176 * careful to avoid modifying the page's queue state once the dequeue
177 * has been requested by setting PGA_DEQUEUE.
180 #if PAGE_SIZE == 4096
181 #define VM_PAGE_BITS_ALL 0xffu
182 typedef uint8_t vm_page_bits_t;
183 #elif PAGE_SIZE == 8192
184 #define VM_PAGE_BITS_ALL 0xffffu
185 typedef uint16_t vm_page_bits_t;
186 #elif PAGE_SIZE == 16384
187 #define VM_PAGE_BITS_ALL 0xffffffffu
188 typedef uint32_t vm_page_bits_t;
189 #elif PAGE_SIZE == 32768
190 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
191 typedef uint64_t vm_page_bits_t;
196 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */
198 SLIST_ENTRY(vm_page) ss; /* private slists */
206 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
207 vm_object_t object; /* which object am I in (O,P) */
208 vm_pindex_t pindex; /* offset into object (O,P) */
209 vm_paddr_t phys_addr; /* physical address of page (C) */
210 struct md_page md; /* machine dependent stuff */
211 u_int wire_count; /* wired down maps refs (P) */
212 volatile u_int busy_lock; /* busy owners lock */
213 uint16_t flags; /* page PG_* flags (P) */
214 uint8_t order; /* index of the buddy queue (F) */
215 uint8_t pool; /* vm_phys freepool index (F) */
216 uint8_t aflags; /* access is atomic */
217 uint8_t oflags; /* page VPO_* flags (O) */
218 uint8_t queue; /* page queue index (Q) */
219 int8_t psind; /* pagesizes[] index (O) */
220 int8_t segind; /* vm_phys segment index (C) */
221 u_char act_count; /* page usage count (P) */
222 /* NOTE that these must support one bit per DEV_BSIZE in a page */
223 /* so, on normal X86 kernels, they must be at least 8 bits wide */
224 vm_page_bits_t valid; /* map of valid DEV_BSIZE chunks (O) */
225 vm_page_bits_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
229 * Page flags stored in oflags:
231 * Access to these page flags is synchronized by the lock on the object
232 * containing the page (O).
234 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
235 * indicates that the page is not under PV management but
236 * otherwise should be treated as a normal page. Pages not
237 * under PV management cannot be paged out via the
238 * object/vm_page_t because there is no knowledge of their pte
239 * mappings, and such pages are also not on any PQ queue.
242 #define VPO_KMEM_EXEC 0x01 /* kmem mapping allows execution */
243 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */
244 #define VPO_UNMANAGED 0x04 /* no PV management for page */
245 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */
246 #define VPO_NOSYNC 0x10 /* do not collect for syncer */
249 * Busy page implementation details.
250 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation,
251 * even if the support for owner identity is removed because of size
252 * constraints. Checks on lock recursion are then not possible, while the
253 * lock assertions effectiveness is someway reduced.
255 #define VPB_BIT_SHARED 0x01
256 #define VPB_BIT_EXCLUSIVE 0x02
257 #define VPB_BIT_WAITERS 0x04
258 #define VPB_BIT_FLAGMASK \
259 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS)
261 #define VPB_SHARERS_SHIFT 3
262 #define VPB_SHARERS(x) \
263 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT)
264 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED)
265 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT)
267 #define VPB_SINGLE_EXCLUSIVER VPB_BIT_EXCLUSIVE
269 #define VPB_UNBUSIED VPB_SHARERS_WORD(0)
272 #define PQ_INACTIVE 0
275 #define PQ_UNSWAPPABLE 3
278 #ifndef VM_PAGE_HAVE_PGLIST
279 TAILQ_HEAD(pglist, vm_page);
280 #define VM_PAGE_HAVE_PGLIST
282 SLIST_HEAD(spglist, vm_page);
285 extern vm_page_t bogus_page;
288 extern struct mtx_padalign pa_lock[];
291 #define PDRSHIFT PDR_SHIFT
292 #elif !defined(PDRSHIFT)
296 #define pa_index(pa) ((pa) >> PDRSHIFT)
297 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT]))
298 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
299 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
300 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
301 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
302 #define PA_UNLOCK_COND(pa) \
310 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
312 #if defined(KLD_MODULE) && !defined(KLD_TIED)
313 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
314 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
315 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
316 #else /* !KLD_MODULE */
317 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
318 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
319 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
320 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
322 #if defined(INVARIANTS)
323 #define vm_page_assert_locked(m) \
324 vm_page_assert_locked_KBI((m), __FILE__, __LINE__)
325 #define vm_page_lock_assert(m, a) \
326 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
328 #define vm_page_assert_locked(m)
329 #define vm_page_lock_assert(m, a)
333 * The vm_page's aflags are updated using atomic operations. To set or clear
334 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
335 * must be used. Neither these flags nor these functions are part of the KBI.
337 * PGA_REFERENCED may be cleared only if the page is locked. It is set by
338 * both the MI and MD VM layers. However, kernel loadable modules should not
339 * directly set this flag. They should call vm_page_reference() instead.
341 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter().
342 * When it does so, the object must be locked, or the page must be
343 * exclusive busied. The MI VM layer must never access this flag
344 * directly. Instead, it should call pmap_page_is_write_mapped().
346 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
347 * at least one executable mapping. It is not consumed by the MI VM layer.
349 * PGA_ENQUEUED is set and cleared when a page is inserted into or removed
350 * from a page queue, respectively. It determines whether the plinks.q field
351 * of the page is valid. To set or clear this flag, the queue lock for the
352 * page must be held: the page queue lock corresponding to the page's "queue"
353 * field if its value is not PQ_NONE, and the page lock otherwise.
355 * PGA_DEQUEUE is set when the page is scheduled to be dequeued from a page
356 * queue, and cleared when the dequeue request is processed. A page may
357 * have PGA_DEQUEUE set and PGA_ENQUEUED cleared, for instance if a dequeue
358 * is requested after the page is scheduled to be enqueued but before it is
359 * actually inserted into the page queue. For allocated pages, the page lock
360 * must be held to set this flag, but it may be set by vm_page_free_prep()
361 * without the page lock held. The page queue lock must be held to clear the
364 * PGA_REQUEUE is set when the page is scheduled to be enqueued or requeued
365 * in its page queue. The page lock must be held to set this flag, and the
366 * queue lock for the page must be held to clear it.
368 * PGA_REQUEUE_HEAD is a special flag for enqueuing pages near the head of
369 * the inactive queue, thus bypassing LRU. The page lock must be held to
370 * set this flag, and the queue lock for the page must be held to clear it.
372 #define PGA_WRITEABLE 0x01 /* page may be mapped writeable */
373 #define PGA_REFERENCED 0x02 /* page has been referenced */
374 #define PGA_EXECUTABLE 0x04 /* page may be mapped executable */
375 #define PGA_ENQUEUED 0x08 /* page is enqueued in a page queue */
376 #define PGA_DEQUEUE 0x10 /* page is due to be dequeued */
377 #define PGA_REQUEUE 0x20 /* page is due to be requeued */
378 #define PGA_REQUEUE_HEAD 0x40 /* page requeue should bypass LRU */
380 #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_DEQUEUE | PGA_REQUEUE | \
384 * Page flags. If changed at any other time than page allocation or
385 * freeing, the modification must be protected by the vm_page lock.
387 * The PG_PCPU_CACHE flag is set at allocation time if the page was
388 * allocated from a per-CPU cache. It is cleared the next time that the
389 * page is allocated from the physical memory allocator.
391 #define PG_PCPU_CACHE 0x0001 /* was allocated from per-CPU caches */
392 #define PG_FICTITIOUS 0x0004 /* physical page doesn't exist */
393 #define PG_ZERO 0x0008 /* page is zeroed */
394 #define PG_MARKER 0x0010 /* special queue marker page */
395 #define PG_NODUMP 0x0080 /* don't include this page in a dump */
400 #define ACT_DECLINE 1
401 #define ACT_ADVANCE 3
407 #include <sys/systm.h>
409 #include <machine/atomic.h>
412 * Each pageable resident page falls into one of five lists:
415 * Available for allocation now.
418 * Low activity, candidates for reclamation.
419 * This list is approximately LRU ordered.
422 * This is the list of pages that should be
426 * Dirty anonymous pages that cannot be paged
427 * out because no swap device is configured.
430 * Pages that are "active", i.e., they have been
431 * recently referenced.
435 extern vm_page_t vm_page_array; /* First resident page in table */
436 extern long vm_page_array_size; /* number of vm_page_t's */
437 extern long first_page; /* first physical page number */
439 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
442 * PHYS_TO_VM_PAGE() returns the vm_page_t object that represents a memory
443 * page to which the given physical address belongs. The correct vm_page_t
444 * object is returned for addresses that are not page-aligned.
446 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
449 * Page allocation parameters for vm_page for the functions
450 * vm_page_alloc(), vm_page_grab(), vm_page_alloc_contig() and
451 * vm_page_alloc_freelist(). Some functions support only a subset
452 * of the flags, and ignore others, see the flags legend.
454 * The meaning of VM_ALLOC_ZERO differs slightly between the vm_page_alloc*()
455 * and the vm_page_grab*() functions. See these functions for details.
457 * Bits 0 - 1 define class.
458 * Bits 2 - 15 dedicated for flags.
460 * (a) - vm_page_alloc() supports the flag.
461 * (c) - vm_page_alloc_contig() supports the flag.
462 * (f) - vm_page_alloc_freelist() supports the flag.
463 * (g) - vm_page_grab() supports the flag.
464 * (p) - vm_page_grab_pages() supports the flag.
465 * Bits above 15 define the count of additional pages that the caller
466 * intends to allocate.
468 #define VM_ALLOC_NORMAL 0
469 #define VM_ALLOC_INTERRUPT 1
470 #define VM_ALLOC_SYSTEM 2
471 #define VM_ALLOC_CLASS_MASK 3
472 #define VM_ALLOC_WAITOK 0x0008 /* (acf) Sleep and retry */
473 #define VM_ALLOC_WAITFAIL 0x0010 /* (acf) Sleep and return error */
474 #define VM_ALLOC_WIRED 0x0020 /* (acfgp) Allocate a wired page */
475 #define VM_ALLOC_ZERO 0x0040 /* (acfgp) Allocate a prezeroed page */
476 #define VM_ALLOC_NOOBJ 0x0100 /* (acg) No associated object */
477 #define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the page */
478 #define VM_ALLOC_IGN_SBUSY 0x1000 /* (gp) Ignore shared busy flag */
479 #define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */
480 #define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */
481 #define VM_ALLOC_NOWAIT 0x8000 /* (acfgp) Do not sleep */
482 #define VM_ALLOC_COUNT_SHIFT 16
483 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
487 malloc2vm_flags(int malloc_flags)
491 KASSERT((malloc_flags & M_USE_RESERVE) == 0 ||
492 (malloc_flags & M_NOWAIT) != 0,
493 ("M_USE_RESERVE requires M_NOWAIT"));
494 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT :
496 if ((malloc_flags & M_ZERO) != 0)
497 pflags |= VM_ALLOC_ZERO;
498 if ((malloc_flags & M_NODUMP) != 0)
499 pflags |= VM_ALLOC_NODUMP;
500 if ((malloc_flags & M_NOWAIT))
501 pflags |= VM_ALLOC_NOWAIT;
502 if ((malloc_flags & M_WAITOK))
503 pflags |= VM_ALLOC_WAITOK;
509 * Predicates supported by vm_page_ps_test():
511 * PS_ALL_DIRTY is true only if the entire (super)page is dirty.
512 * However, it can be spuriously false when the (super)page has become
513 * dirty in the pmap but that information has not been propagated to the
514 * machine-independent layer.
516 #define PS_ALL_DIRTY 0x1
517 #define PS_ALL_VALID 0x2
518 #define PS_NONE_BUSY 0x4
520 void vm_page_busy_downgrade(vm_page_t m);
521 void vm_page_busy_sleep(vm_page_t m, const char *msg, bool nonshared);
522 void vm_page_flash(vm_page_t m);
523 void vm_page_free(vm_page_t m);
524 void vm_page_free_zero(vm_page_t m);
526 void vm_page_activate (vm_page_t);
527 void vm_page_advise(vm_page_t m, int advice);
528 vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int);
529 vm_page_t vm_page_alloc_domain(vm_object_t, vm_pindex_t, int, int);
530 vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t);
531 vm_page_t vm_page_alloc_domain_after(vm_object_t, vm_pindex_t, int, int,
533 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
534 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
535 vm_paddr_t boundary, vm_memattr_t memattr);
536 vm_page_t vm_page_alloc_contig_domain(vm_object_t object,
537 vm_pindex_t pindex, int domain, int req, u_long npages, vm_paddr_t low,
538 vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
539 vm_memattr_t memattr);
540 vm_page_t vm_page_alloc_freelist(int, int);
541 vm_page_t vm_page_alloc_freelist_domain(int, int, int);
542 bool vm_page_blacklist_add(vm_paddr_t pa, bool verbose);
543 void vm_page_change_lock(vm_page_t m, struct mtx **mtx);
544 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
545 int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags,
546 vm_page_t *ma, int count);
547 void vm_page_deactivate(vm_page_t);
548 void vm_page_deactivate_noreuse(vm_page_t);
549 void vm_page_dequeue(vm_page_t m);
550 void vm_page_dequeue_deferred(vm_page_t m);
551 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
552 bool vm_page_free_prep(vm_page_t m);
553 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
554 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
555 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
556 void vm_page_launder(vm_page_t m);
557 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
558 vm_page_t vm_page_next(vm_page_t m);
559 int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *);
560 void vm_page_pqbatch_drain(void);
561 void vm_page_pqbatch_submit(vm_page_t m, uint8_t queue);
562 vm_page_t vm_page_prev(vm_page_t m);
563 bool vm_page_ps_test(vm_page_t m, int flags, vm_page_t skip_m);
564 void vm_page_putfake(vm_page_t m);
565 void vm_page_readahead_finish(vm_page_t m);
566 bool vm_page_reclaim_contig(int req, u_long npages, vm_paddr_t low,
567 vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
568 bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages,
569 vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
570 void vm_page_reference(vm_page_t m);
571 #define VPR_TRYFREE 0x01
572 #define VPR_NOREUSE 0x02
573 void vm_page_release(vm_page_t m, int flags);
574 void vm_page_release_locked(vm_page_t m, int flags);
575 bool vm_page_remove(vm_page_t);
576 int vm_page_rename(vm_page_t, vm_object_t, vm_pindex_t);
577 vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object,
579 void vm_page_requeue(vm_page_t m);
580 int vm_page_sbusied(vm_page_t m);
581 vm_page_t vm_page_scan_contig(u_long npages, vm_page_t m_start,
582 vm_page_t m_end, u_long alignment, vm_paddr_t boundary, int options);
583 void vm_page_set_valid_range(vm_page_t m, int base, int size);
584 int vm_page_sleep_if_busy(vm_page_t m, const char *msg);
585 vm_offset_t vm_page_startup(vm_offset_t vaddr);
586 void vm_page_sunbusy(vm_page_t m);
587 void vm_page_swapqueue(vm_page_t m, uint8_t oldq, uint8_t newq);
588 int vm_page_trysbusy(vm_page_t m);
589 void vm_page_unhold_pages(vm_page_t *ma, int count);
590 void vm_page_unswappable(vm_page_t m);
591 bool vm_page_unwire(vm_page_t m, uint8_t queue);
592 bool vm_page_unwire_noq(vm_page_t m);
593 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
594 void vm_page_wire (vm_page_t);
595 void vm_page_xunbusy_hard(vm_page_t m);
596 void vm_page_xunbusy_maybelocked(vm_page_t m);
597 void vm_page_set_validclean (vm_page_t, int, int);
598 void vm_page_clear_dirty (vm_page_t, int, int);
599 void vm_page_set_invalid (vm_page_t, int, int);
600 int vm_page_is_valid (vm_page_t, int, int);
601 void vm_page_test_dirty (vm_page_t);
602 vm_page_bits_t vm_page_bits(int base, int size);
603 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
604 void vm_page_free_toq(vm_page_t m);
605 void vm_page_free_pages_toq(struct spglist *free, bool update_wire_count);
607 void vm_page_dirty_KBI(vm_page_t m);
608 void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
609 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
610 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
611 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
612 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line);
613 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
616 #define vm_page_assert_sbusied(m) \
617 KASSERT(vm_page_sbusied(m), \
618 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \
619 (m), __FILE__, __LINE__))
621 #define vm_page_assert_unbusied(m) \
622 KASSERT(!vm_page_busied(m), \
623 ("vm_page_assert_unbusied: page %p busy @ %s:%d", \
624 (m), __FILE__, __LINE__))
626 #define vm_page_assert_xbusied(m) \
627 KASSERT(vm_page_xbusied(m), \
628 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \
629 (m), __FILE__, __LINE__))
631 #define vm_page_busied(m) \
632 ((m)->busy_lock != VPB_UNBUSIED)
634 #define vm_page_sbusy(m) do { \
635 if (!vm_page_trysbusy(m)) \
636 panic("%s: page %p failed shared busying", __func__, \
640 #define vm_page_tryxbusy(m) \
641 (atomic_cmpset_acq_int(&(m)->busy_lock, VPB_UNBUSIED, \
642 VPB_SINGLE_EXCLUSIVER))
644 #define vm_page_xbusied(m) \
645 (((m)->busy_lock & VPB_SINGLE_EXCLUSIVER) != 0)
647 #define vm_page_xbusy(m) do { \
648 if (!vm_page_tryxbusy(m)) \
649 panic("%s: page %p failed exclusive busying", __func__, \
653 /* Note: page m's lock must not be owned by the caller. */
654 #define vm_page_xunbusy(m) do { \
655 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
656 VPB_SINGLE_EXCLUSIVER, VPB_UNBUSIED)) \
657 vm_page_xunbusy_hard(m); \
661 void vm_page_object_lock_assert(vm_page_t m);
662 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m)
663 void vm_page_assert_pga_writeable(vm_page_t m, uint8_t bits);
664 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) \
665 vm_page_assert_pga_writeable(m, bits)
667 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
668 #define VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits) (void)0
672 * We want to use atomic updates for the aflags field, which is 8 bits wide.
673 * However, not all architectures support atomic operations on 8-bit
674 * destinations. In order that we can easily use a 32-bit operation, we
675 * require that the aflags field be 32-bit aligned.
677 _Static_assert(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0,
678 "aflags field is not 32-bit aligned");
681 * We want to be able to update the aflags and queue fields atomically in
682 * the same operation.
684 _Static_assert(offsetof(struct vm_page, aflags) / sizeof(uint32_t) ==
685 offsetof(struct vm_page, queue) / sizeof(uint32_t),
686 "aflags and queue fields do not belong to the same 32-bit word");
687 _Static_assert(offsetof(struct vm_page, queue) % sizeof(uint32_t) == 2,
688 "queue field is at an unexpected offset");
689 _Static_assert(sizeof(((struct vm_page *)NULL)->queue) == 1,
690 "queue field has an unexpected size");
692 #if BYTE_ORDER == LITTLE_ENDIAN
693 #define VM_PAGE_AFLAG_SHIFT 0
694 #define VM_PAGE_QUEUE_SHIFT 16
696 #define VM_PAGE_AFLAG_SHIFT 24
697 #define VM_PAGE_QUEUE_SHIFT 8
699 #define VM_PAGE_QUEUE_MASK (0xff << VM_PAGE_QUEUE_SHIFT)
702 * Clear the given bits in the specified page.
705 vm_page_aflag_clear(vm_page_t m, uint8_t bits)
710 * The PGA_REFERENCED flag can only be cleared if the page is locked.
712 if ((bits & PGA_REFERENCED) != 0)
713 vm_page_assert_locked(m);
716 * Access the whole 32-bit word containing the aflags field with an
717 * atomic update. Parallel non-atomic updates to the other fields
718 * within this word are handled properly by the atomic update.
720 addr = (void *)&m->aflags;
721 val = bits << VM_PAGE_AFLAG_SHIFT;
722 atomic_clear_32(addr, val);
726 * Set the given bits in the specified page.
729 vm_page_aflag_set(vm_page_t m, uint8_t bits)
733 VM_PAGE_ASSERT_PGA_WRITEABLE(m, bits);
736 * Access the whole 32-bit word containing the aflags field with an
737 * atomic update. Parallel non-atomic updates to the other fields
738 * within this word are handled properly by the atomic update.
740 addr = (void *)&m->aflags;
741 val = bits << VM_PAGE_AFLAG_SHIFT;
742 atomic_set_32(addr, val);
746 * Atomically update the queue state of the page. The operation fails if
747 * any of the queue flags in "fflags" are set or if the "queue" field of
748 * the page does not match the expected value; if the operation is
749 * successful, the flags in "nflags" are set and all other queue state
753 vm_page_pqstate_cmpset(vm_page_t m, uint32_t oldq, uint32_t newq,
754 uint32_t fflags, uint32_t nflags)
756 uint32_t *addr, nval, oval, qsmask;
758 vm_page_assert_locked(m);
760 fflags <<= VM_PAGE_AFLAG_SHIFT;
761 nflags <<= VM_PAGE_AFLAG_SHIFT;
762 newq <<= VM_PAGE_QUEUE_SHIFT;
763 oldq <<= VM_PAGE_QUEUE_SHIFT;
764 qsmask = ((PGA_DEQUEUE | PGA_REQUEUE | PGA_REQUEUE_HEAD) <<
765 VM_PAGE_AFLAG_SHIFT) | VM_PAGE_QUEUE_MASK;
767 addr = (void *)&m->aflags;
768 oval = atomic_load_32(addr);
770 if ((oval & fflags) != 0)
772 if ((oval & VM_PAGE_QUEUE_MASK) != oldq)
774 nval = (oval & ~qsmask) | nflags | newq;
775 } while (!atomic_fcmpset_32(addr, &oval, nval));
783 * Set all bits in the page's dirty field.
785 * The object containing the specified page must be locked if the
786 * call is made from the machine-independent layer.
788 * See vm_page_clear_dirty_mask().
791 vm_page_dirty(vm_page_t m)
794 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
795 #if (defined(KLD_MODULE) && !defined(KLD_TIED)) || defined(INVARIANTS)
796 vm_page_dirty_KBI(m);
798 m->dirty = VM_PAGE_BITS_ALL;
805 * Set page to not be dirty. Note: does not clear pmap modify bits
808 vm_page_undirty(vm_page_t m)
811 VM_PAGE_OBJECT_LOCK_ASSERT(m);
816 vm_page_replace_checked(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex,
821 mret = vm_page_replace(mnew, object, pindex);
822 KASSERT(mret == mold,
823 ("invalid page replacement, mold=%p, mret=%p", mold, mret));
825 /* Unused if !INVARIANTS. */
833 * Return the index of the queue containing m. This index is guaranteed
834 * not to change while the page lock is held.
836 static inline uint8_t
837 vm_page_queue(vm_page_t m)
840 vm_page_assert_locked(m);
842 if ((m->aflags & PGA_DEQUEUE) != 0)
844 atomic_thread_fence_acq();
849 vm_page_active(vm_page_t m)
852 return (vm_page_queue(m) == PQ_ACTIVE);
856 vm_page_inactive(vm_page_t m)
859 return (vm_page_queue(m) == PQ_INACTIVE);
863 vm_page_in_laundry(vm_page_t m)
867 queue = vm_page_queue(m);
868 return (queue == PQ_LAUNDRY || queue == PQ_UNSWAPPABLE);
874 * Return true if a reference prevents the page from being reclaimable.
877 vm_page_wired(vm_page_t m)
880 return (m->wire_count > 0);
884 #endif /* !_VM_PAGE_ */