2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
35 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36 * All rights reserved.
38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
50 * Carnegie Mellon requests users of this software to return to
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
64 * Resident memory system definitions.
73 * Management of resident (logical) pages.
75 * A small structure is kept for each resident
76 * page, indexed by page number. Each structure
77 * is an element of several collections:
79 * A radix tree used to quickly
80 * perform object/offset lookups
82 * A list of all pages for a given object,
83 * so they can be quickly deactivated at
84 * time of deallocation.
86 * An ordered list of pages due for pageout.
88 * In addition, the structure contains the object
89 * and offset to which this page belongs (for pageout),
90 * and sundry status bits.
92 * In general, operations on this structure's mutable fields are
93 * synchronized using either one of or a combination of the lock on the
94 * object that the page belongs to (O), the pool lock for the page (P),
95 * or the lock for either the free or paging queue (Q). If a field is
96 * annotated below with two of these locks, then holding either lock is
97 * sufficient for read access, but both locks are required for write
100 * In contrast, the synchronization of accesses to the page's
101 * dirty field is machine dependent (M). In the
102 * machine-independent layer, the lock on the object that the
103 * page belongs to must be held in order to operate on the field.
104 * However, the pmap layer is permitted to set all bits within
105 * the field without holding that lock. If the underlying
106 * architecture does not support atomic read-modify-write
107 * operations on the field's type, then the machine-independent
108 * layer uses a 32-bit atomic on the aligned 32-bit word that
109 * contains the dirty field. In the machine-independent layer,
110 * the implementation of read-modify-write operations on the
111 * field is encapsulated in vm_page_clear_dirty_mask().
114 #if PAGE_SIZE == 4096
115 #define VM_PAGE_BITS_ALL 0xffu
116 typedef uint8_t vm_page_bits_t;
117 #elif PAGE_SIZE == 8192
118 #define VM_PAGE_BITS_ALL 0xffffu
119 typedef uint16_t vm_page_bits_t;
120 #elif PAGE_SIZE == 16384
121 #define VM_PAGE_BITS_ALL 0xffffffffu
122 typedef uint32_t vm_page_bits_t;
123 #elif PAGE_SIZE == 32768
124 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
125 typedef uint64_t vm_page_bits_t;
130 TAILQ_ENTRY(vm_page) q; /* page queue or free list (Q) */
132 SLIST_ENTRY(vm_page) ss; /* private slists */
140 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
141 vm_object_t object; /* which object am I in (O,P) */
142 vm_pindex_t pindex; /* offset into object (O,P) */
143 vm_paddr_t phys_addr; /* physical address of page */
144 struct md_page md; /* machine dependant stuff */
145 u_int wire_count; /* wired down maps refs (P) */
146 volatile u_int busy_lock; /* busy owners lock */
147 uint16_t hold_count; /* page hold count (P) */
148 uint16_t flags; /* page PG_* flags (P) */
149 uint8_t aflags; /* access is atomic */
150 uint8_t oflags; /* page VPO_* flags (O) */
151 uint8_t queue; /* page queue index (P,Q) */
152 int8_t psind; /* pagesizes[] index (O) */
154 uint8_t order; /* index of the buddy queue */
156 u_char act_count; /* page usage count (P) */
157 /* NOTE that these must support one bit per DEV_BSIZE in a page */
158 /* so, on normal X86 kernels, they must be at least 8 bits wide */
159 vm_page_bits_t valid; /* map of valid DEV_BSIZE chunks (O) */
160 vm_page_bits_t dirty; /* map of dirty DEV_BSIZE chunks (M) */
164 * Page flags stored in oflags:
166 * Access to these page flags is synchronized by the lock on the object
167 * containing the page (O).
169 * Note: VPO_UNMANAGED (used by OBJT_DEVICE, OBJT_PHYS and OBJT_SG)
170 * indicates that the page is not under PV management but
171 * otherwise should be treated as a normal page. Pages not
172 * under PV management cannot be paged out via the
173 * object/vm_page_t because there is no knowledge of their pte
174 * mappings, and such pages are also not on any PQ queue.
177 #define VPO_UNUSED01 0x01 /* --available-- */
178 #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */
179 #define VPO_UNMANAGED 0x04 /* no PV management for page */
180 #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */
181 #define VPO_NOSYNC 0x10 /* do not collect for syncer */
184 * Busy page implementation details.
185 * The algorithm is taken mostly by rwlock(9) and sx(9) locks implementation,
186 * even if the support for owner identity is removed because of size
187 * constraints. Checks on lock recursion are then not possible, while the
188 * lock assertions effectiveness is someway reduced.
190 #define VPB_BIT_SHARED 0x01
191 #define VPB_BIT_EXCLUSIVE 0x02
192 #define VPB_BIT_WAITERS 0x04
193 #define VPB_BIT_FLAGMASK \
194 (VPB_BIT_SHARED | VPB_BIT_EXCLUSIVE | VPB_BIT_WAITERS)
196 #define VPB_SHARERS_SHIFT 3
197 #define VPB_SHARERS(x) \
198 (((x) & ~VPB_BIT_FLAGMASK) >> VPB_SHARERS_SHIFT)
199 #define VPB_SHARERS_WORD(x) ((x) << VPB_SHARERS_SHIFT | VPB_BIT_SHARED)
200 #define VPB_ONE_SHARER (1 << VPB_SHARERS_SHIFT)
202 #define VPB_SINGLE_EXCLUSIVER VPB_BIT_EXCLUSIVE
204 #define VPB_UNBUSIED VPB_SHARERS_WORD(0)
207 #define PQ_INACTIVE 0
211 TAILQ_HEAD(pglist, vm_page);
212 SLIST_HEAD(spglist, vm_page);
214 struct vm_pagequeue {
219 const char * const pq_name;
220 } __aligned(CACHE_LINE_SIZE);
224 struct vm_pagequeue vmd_pagequeues[PQ_COUNT];
225 u_int vmd_page_count;
226 u_int vmd_free_count;
227 long vmd_segs; /* bitmask of the segments */
229 int vmd_pass; /* local pagedaemon pass */
230 struct vm_page vmd_marker; /* marker for pagedaemon private use */
233 extern struct vm_domain vm_dom[MAXMEMDOM];
235 #define vm_pagequeue_assert_locked(pq) mtx_assert(&(pq)->pq_mutex, MA_OWNED)
236 #define vm_pagequeue_lock(pq) mtx_lock(&(pq)->pq_mutex)
237 #define vm_pagequeue_unlock(pq) mtx_unlock(&(pq)->pq_mutex)
241 vm_pagequeue_cnt_add(struct vm_pagequeue *pq, int addend)
245 vm_pagequeue_assert_locked(pq);
247 pq->pq_cnt += addend;
248 atomic_add_int(pq->pq_vcnt, addend);
250 #define vm_pagequeue_cnt_inc(pq) vm_pagequeue_cnt_add((pq), 1)
251 #define vm_pagequeue_cnt_dec(pq) vm_pagequeue_cnt_add((pq), -1)
254 extern struct mtx_padalign vm_page_queue_free_mtx;
255 extern struct mtx_padalign pa_lock[];
258 #define PDRSHIFT PDR_SHIFT
259 #elif !defined(PDRSHIFT)
263 #define pa_index(pa) ((pa) >> PDRSHIFT)
264 #define PA_LOCKPTR(pa) ((struct mtx *)(&pa_lock[pa_index(pa) % PA_LOCK_COUNT]))
265 #define PA_LOCKOBJPTR(pa) ((struct lock_object *)PA_LOCKPTR((pa)))
266 #define PA_LOCK(pa) mtx_lock(PA_LOCKPTR(pa))
267 #define PA_TRYLOCK(pa) mtx_trylock(PA_LOCKPTR(pa))
268 #define PA_UNLOCK(pa) mtx_unlock(PA_LOCKPTR(pa))
269 #define PA_UNLOCK_COND(pa) \
277 #define PA_LOCK_ASSERT(pa, a) mtx_assert(PA_LOCKPTR(pa), (a))
280 #define vm_page_lock(m) vm_page_lock_KBI((m), LOCK_FILE, LOCK_LINE)
281 #define vm_page_unlock(m) vm_page_unlock_KBI((m), LOCK_FILE, LOCK_LINE)
282 #define vm_page_trylock(m) vm_page_trylock_KBI((m), LOCK_FILE, LOCK_LINE)
283 #else /* !KLD_MODULE */
284 #define vm_page_lockptr(m) (PA_LOCKPTR(VM_PAGE_TO_PHYS((m))))
285 #define vm_page_lock(m) mtx_lock(vm_page_lockptr((m)))
286 #define vm_page_unlock(m) mtx_unlock(vm_page_lockptr((m)))
287 #define vm_page_trylock(m) mtx_trylock(vm_page_lockptr((m)))
289 #if defined(INVARIANTS)
290 #define vm_page_assert_locked(m) \
291 vm_page_assert_locked_KBI((m), __FILE__, __LINE__)
292 #define vm_page_lock_assert(m, a) \
293 vm_page_lock_assert_KBI((m), (a), __FILE__, __LINE__)
295 #define vm_page_assert_locked(m)
296 #define vm_page_lock_assert(m, a)
300 * The vm_page's aflags are updated using atomic operations. To set or clear
301 * these flags, the functions vm_page_aflag_set() and vm_page_aflag_clear()
302 * must be used. Neither these flags nor these functions are part of the KBI.
304 * PGA_REFERENCED may be cleared only if the page is locked. It is set by
305 * both the MI and MD VM layers. However, kernel loadable modules should not
306 * directly set this flag. They should call vm_page_reference() instead.
308 * PGA_WRITEABLE is set exclusively on managed pages by pmap_enter(). When it
309 * does so, the page must be exclusive busied. The MI VM layer must never
310 * access this flag directly. Instead, it should call
311 * pmap_page_is_write_mapped().
313 * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has
314 * at least one executable mapping. It is not consumed by the MI VM layer.
316 #define PGA_WRITEABLE 0x01 /* page may be mapped writeable */
317 #define PGA_REFERENCED 0x02 /* page has been referenced */
318 #define PGA_EXECUTABLE 0x04 /* page may be mapped executable */
321 * Page flags. If changed at any other time than page allocation or
322 * freeing, the modification must be protected by the vm_page lock.
324 #define PG_CACHED 0x0001 /* page is cached */
325 #define PG_FICTITIOUS 0x0004 /* physical page doesn't exist */
326 #define PG_ZERO 0x0008 /* page is zeroed */
327 #define PG_MARKER 0x0010 /* special queue marker page */
328 #define PG_WINATCFLS 0x0040 /* flush dirty page on inactive q */
329 #define PG_NODUMP 0x0080 /* don't include this page in a dump */
330 #define PG_UNHOLDFREE 0x0100 /* delayed free of a held page */
335 #define ACT_DECLINE 1
336 #define ACT_ADVANCE 3
342 #include <sys/systm.h>
344 #include <machine/atomic.h>
347 * Each pageable resident page falls into one of four lists:
350 * Available for allocation now.
353 * Almost available for allocation. Still associated with
354 * an object, but clean and immediately freeable.
356 * The following lists are LRU sorted:
359 * Low activity, candidates for reclamation.
360 * This is the list of pages that should be
364 * Pages that are "active" i.e. they have been
365 * recently referenced.
369 extern int vm_page_zero_count;
371 extern vm_page_t vm_page_array; /* First resident page in table */
372 extern long vm_page_array_size; /* number of vm_page_t's */
373 extern long first_page; /* first physical page number */
375 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
377 vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
379 /* page allocation classes: */
380 #define VM_ALLOC_NORMAL 0
381 #define VM_ALLOC_INTERRUPT 1
382 #define VM_ALLOC_SYSTEM 2
383 #define VM_ALLOC_CLASS_MASK 3
384 /* page allocation flags: */
385 #define VM_ALLOC_WIRED 0x0020 /* non pageable */
386 #define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
387 #define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
388 #define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
389 #define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
390 #define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
391 #define VM_ALLOC_IGN_SBUSY 0x1000 /* vm_page_grab() only */
392 #define VM_ALLOC_NODUMP 0x2000 /* don't include in dump */
393 #define VM_ALLOC_SBUSY 0x4000 /* Shared busy the page */
395 #define VM_ALLOC_COUNT_SHIFT 16
396 #define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
400 malloc2vm_flags(int malloc_flags)
404 KASSERT((malloc_flags & M_USE_RESERVE) == 0 ||
405 (malloc_flags & M_NOWAIT) != 0,
406 ("M_USE_RESERVE requires M_NOWAIT"));
407 pflags = (malloc_flags & M_USE_RESERVE) != 0 ? VM_ALLOC_INTERRUPT :
409 if ((malloc_flags & M_ZERO) != 0)
410 pflags |= VM_ALLOC_ZERO;
411 if ((malloc_flags & M_NODUMP) != 0)
412 pflags |= VM_ALLOC_NODUMP;
417 void vm_page_busy_downgrade(vm_page_t m);
418 void vm_page_busy_sleep(vm_page_t m, const char *msg);
419 void vm_page_flash(vm_page_t m);
420 void vm_page_hold(vm_page_t mem);
421 void vm_page_unhold(vm_page_t mem);
422 void vm_page_free(vm_page_t m);
423 void vm_page_free_zero(vm_page_t m);
425 void vm_page_activate (vm_page_t);
426 void vm_page_advise(vm_page_t m, int advice);
427 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
428 vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req,
429 u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment,
430 vm_paddr_t boundary, vm_memattr_t memattr);
431 vm_page_t vm_page_alloc_freelist(int, int);
432 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
433 void vm_page_cache(vm_page_t);
434 void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
435 void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
436 int vm_page_try_to_cache (vm_page_t);
437 int vm_page_try_to_free (vm_page_t);
438 void vm_page_deactivate (vm_page_t);
439 void vm_page_dequeue(vm_page_t m);
440 void vm_page_dequeue_locked(vm_page_t m);
441 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
442 vm_page_t vm_page_getfake(vm_paddr_t paddr, vm_memattr_t memattr);
443 void vm_page_initfake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
444 int vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
445 boolean_t vm_page_is_cached(vm_object_t object, vm_pindex_t pindex);
446 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
447 vm_page_t vm_page_next(vm_page_t m);
448 int vm_page_pa_tryrelock(pmap_t, vm_paddr_t, vm_paddr_t *);
449 struct vm_pagequeue *vm_page_pagequeue(vm_page_t m);
450 vm_page_t vm_page_prev(vm_page_t m);
451 boolean_t vm_page_ps_is_valid(vm_page_t m);
452 void vm_page_putfake(vm_page_t m);
453 void vm_page_readahead_finish(vm_page_t m);
454 void vm_page_reference(vm_page_t m);
455 void vm_page_remove (vm_page_t);
456 int vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
457 vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object,
459 void vm_page_requeue(vm_page_t m);
460 void vm_page_requeue_locked(vm_page_t m);
461 int vm_page_sbusied(vm_page_t m);
462 void vm_page_set_valid_range(vm_page_t m, int base, int size);
463 int vm_page_sleep_if_busy(vm_page_t m, const char *msg);
464 vm_offset_t vm_page_startup(vm_offset_t vaddr);
465 void vm_page_sunbusy(vm_page_t m);
466 int vm_page_trysbusy(vm_page_t m);
467 void vm_page_unhold_pages(vm_page_t *ma, int count);
468 void vm_page_unwire (vm_page_t m, uint8_t queue);
469 void vm_page_updatefake(vm_page_t m, vm_paddr_t paddr, vm_memattr_t memattr);
470 void vm_page_wire (vm_page_t);
471 void vm_page_xunbusy_hard(vm_page_t m);
472 void vm_page_set_validclean (vm_page_t, int, int);
473 void vm_page_clear_dirty (vm_page_t, int, int);
474 void vm_page_set_invalid (vm_page_t, int, int);
475 int vm_page_is_valid (vm_page_t, int, int);
476 void vm_page_test_dirty (vm_page_t);
477 vm_page_bits_t vm_page_bits(int base, int size);
478 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
479 void vm_page_free_toq(vm_page_t m);
480 void vm_page_zero_idle_wakeup(void);
482 void vm_page_dirty_KBI(vm_page_t m);
483 void vm_page_lock_KBI(vm_page_t m, const char *file, int line);
484 void vm_page_unlock_KBI(vm_page_t m, const char *file, int line);
485 int vm_page_trylock_KBI(vm_page_t m, const char *file, int line);
486 #if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
487 void vm_page_assert_locked_KBI(vm_page_t m, const char *file, int line);
488 void vm_page_lock_assert_KBI(vm_page_t m, int a, const char *file, int line);
491 #define vm_page_assert_sbusied(m) \
492 KASSERT(vm_page_sbusied(m), \
493 ("vm_page_assert_sbusied: page %p not shared busy @ %s:%d", \
494 (void *)m, __FILE__, __LINE__));
496 #define vm_page_assert_unbusied(m) \
497 KASSERT(!vm_page_busied(m), \
498 ("vm_page_assert_unbusied: page %p busy @ %s:%d", \
499 (void *)m, __FILE__, __LINE__));
501 #define vm_page_assert_xbusied(m) \
502 KASSERT(vm_page_xbusied(m), \
503 ("vm_page_assert_xbusied: page %p not exclusive busy @ %s:%d", \
504 (void *)m, __FILE__, __LINE__));
506 #define vm_page_busied(m) \
507 ((m)->busy_lock != VPB_UNBUSIED)
509 #define vm_page_sbusy(m) do { \
510 if (!vm_page_trysbusy(m)) \
511 panic("%s: page %p failed shared busing", __func__, m); \
514 #define vm_page_tryxbusy(m) \
515 (atomic_cmpset_acq_int(&m->busy_lock, VPB_UNBUSIED, \
516 VPB_SINGLE_EXCLUSIVER))
518 #define vm_page_xbusied(m) \
519 ((m->busy_lock & VPB_SINGLE_EXCLUSIVER) != 0)
521 #define vm_page_xbusy(m) do { \
522 if (!vm_page_tryxbusy(m)) \
523 panic("%s: page %p failed exclusive busing", __func__, \
527 #define vm_page_xunbusy(m) do { \
528 if (!atomic_cmpset_rel_int(&(m)->busy_lock, \
529 VPB_SINGLE_EXCLUSIVER, VPB_UNBUSIED)) \
530 vm_page_xunbusy_hard(m); \
534 void vm_page_object_lock_assert(vm_page_t m);
535 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) vm_page_object_lock_assert(m)
537 #define VM_PAGE_OBJECT_LOCK_ASSERT(m) (void)0
541 * We want to use atomic updates for the aflags field, which is 8 bits wide.
542 * However, not all architectures support atomic operations on 8-bit
543 * destinations. In order that we can easily use a 32-bit operation, we
544 * require that the aflags field be 32-bit aligned.
546 CTASSERT(offsetof(struct vm_page, aflags) % sizeof(uint32_t) == 0);
549 * Clear the given bits in the specified page.
552 vm_page_aflag_clear(vm_page_t m, uint8_t bits)
557 * The PGA_REFERENCED flag can only be cleared if the page is locked.
559 if ((bits & PGA_REFERENCED) != 0)
560 vm_page_assert_locked(m);
563 * Access the whole 32-bit word containing the aflags field with an
564 * atomic update. Parallel non-atomic updates to the other fields
565 * within this word are handled properly by the atomic update.
567 addr = (void *)&m->aflags;
568 KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
569 ("vm_page_aflag_clear: aflags is misaligned"));
571 #if BYTE_ORDER == BIG_ENDIAN
574 atomic_clear_32(addr, val);
578 * Set the given bits in the specified page.
581 vm_page_aflag_set(vm_page_t m, uint8_t bits)
586 * The PGA_WRITEABLE flag can only be set if the page is managed and
587 * exclusive busied. Currently, this flag is only set by pmap_enter().
589 KASSERT((bits & PGA_WRITEABLE) == 0 ||
590 ((m->oflags & VPO_UNMANAGED) == 0 && vm_page_xbusied(m)),
591 ("vm_page_aflag_set: PGA_WRITEABLE and not exclusive busy"));
594 * Access the whole 32-bit word containing the aflags field with an
595 * atomic update. Parallel non-atomic updates to the other fields
596 * within this word are handled properly by the atomic update.
598 addr = (void *)&m->aflags;
599 KASSERT(((uintptr_t)addr & (sizeof(uint32_t) - 1)) == 0,
600 ("vm_page_aflag_set: aflags is misaligned"));
602 #if BYTE_ORDER == BIG_ENDIAN
605 atomic_set_32(addr, val);
611 * Set all bits in the page's dirty field.
613 * The object containing the specified page must be locked if the
614 * call is made from the machine-independent layer.
616 * See vm_page_clear_dirty_mask().
619 vm_page_dirty(vm_page_t m)
622 /* Use vm_page_dirty_KBI() under INVARIANTS to save memory. */
623 #if defined(KLD_MODULE) || defined(INVARIANTS)
624 vm_page_dirty_KBI(m);
626 m->dirty = VM_PAGE_BITS_ALL;
633 * If the given page is in a page queue, then remove it from that page
636 * The page must be locked.
639 vm_page_remque(vm_page_t m)
642 if (m->queue != PQ_NONE)
649 * Set page to not be dirty. Note: does not clear pmap modify bits
652 vm_page_undirty(vm_page_t m)
655 VM_PAGE_OBJECT_LOCK_ASSERT(m);
660 #endif /* !_VM_PAGE_ */