FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_page.h
1 /*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
33 *
34 *
35 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
36 * All rights reserved.
37 *
38 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
39 *
40 * Permission to use, copy, modify and distribute this software and
41 * its documentation is hereby granted, provided that both the copyright
42 * notice and this permission notice appear in all copies of the
43 * software, derivative works or modified versions, and any portions
44 * thereof, and that both notices appear in supporting documentation.
45 *
46 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
47 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
48 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
49 *
50 * Carnegie Mellon requests users of this software to return to
51 *
52 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
53 * School of Computer Science
54 * Carnegie Mellon University
55 * Pittsburgh PA 15213-3890
56 *
57 * any improvements or extensions that they make and grant Carnegie the
58 * rights to redistribute these changes.
59 *
60 * $FreeBSD: releng/8.3/sys/vm/vm_page.h 215979 2010-11-28 06:43:39Z jchandra $
61 */
62
63 /*
64 * Resident memory system definitions.
65 */
66
67 #ifndef _VM_PAGE_
68 #define _VM_PAGE_
69
70 #include <vm/pmap.h>
71
72 /*
73 * Management of resident (logical) pages.
74 *
75 * A small structure is kept for each resident
76 * page, indexed by page number. Each structure
77 * is an element of several lists:
78 *
79 * A hash table bucket used to quickly
80 * perform object/offset lookups
81 *
82 * A list of all pages for a given object,
83 * so they can be quickly deactivated at
84 * time of deallocation.
85 *
86 * An ordered list of pages due for pageout.
87 *
88 * In addition, the structure contains the object
89 * and offset to which this page belongs (for pageout),
90 * and sundry status bits.
91 *
92 * Fields in this structure are locked either by the lock on the
93 * object that the page belongs to (O) or by the lock on the page
94 * queues (P).
95 */
96
97 TAILQ_HEAD(pglist, vm_page);
98
99 struct vm_page {
100 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */
101 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
102 struct vm_page *left; /* splay tree link (O) */
103 struct vm_page *right; /* splay tree link (O) */
104
105 vm_object_t object; /* which object am I in (O,P)*/
106 vm_pindex_t pindex; /* offset into object (O,P) */
107 vm_paddr_t phys_addr; /* physical address of page */
108 struct md_page md; /* machine dependant stuff */
109 uint8_t queue; /* page queue index */
110 int8_t segind;
111 u_short flags; /* see below */
112 uint8_t order; /* index of the buddy queue */
113 uint8_t pool;
114 u_short cow; /* page cow mapping count */
115 u_int wire_count; /* wired down maps refs (P) */
116 short hold_count; /* page hold count */
117 u_short oflags; /* page flags (O) */
118 u_char act_count; /* page usage count */
119 u_char busy; /* page busy count (O) */
120 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
121 /* so, on normal X86 kernels, they must be at least 8 bits wide */
122 #if PAGE_SIZE == 4096
123 u_char valid; /* map of valid DEV_BSIZE chunks (O) */
124 u_char dirty; /* map of dirty DEV_BSIZE chunks */
125 #elif PAGE_SIZE == 8192
126 u_short valid; /* map of valid DEV_BSIZE chunks (O) */
127 u_short dirty; /* map of dirty DEV_BSIZE chunks */
128 #elif PAGE_SIZE == 16384
129 u_int valid; /* map of valid DEV_BSIZE chunks (O) */
130 u_int dirty; /* map of dirty DEV_BSIZE chunks */
131 #elif PAGE_SIZE == 32768
132 u_long valid; /* map of valid DEV_BSIZE chunks (O) */
133 u_long dirty; /* map of dirty DEV_BSIZE chunks */
134 #endif
135 };
136
137 /*
138 * Page flags stored in oflags:
139 *
140 * Access to these page flags is synchronized by the lock on the object
141 * containing the page (O).
142 */
143 #define VPO_BUSY 0x0001 /* page is in transit */
144 #define VPO_WANTED 0x0002 /* someone is waiting for page */
145 #define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */
146 #define VPO_NOSYNC 0x0400 /* do not collect for syncer */
147
148 #define PQ_NONE 0
149 #define PQ_INACTIVE 1
150 #define PQ_ACTIVE 2
151 #define PQ_HOLD 3
152 #define PQ_COUNT 4
153
154 /* Returns the real queue a page is on. */
155 #define VM_PAGE_GETQUEUE(m) ((m)->queue)
156
157 /* Returns the well known queue a page is on. */
158 #define VM_PAGE_GETKNOWNQUEUE2(m) VM_PAGE_GETQUEUE(m)
159
160 /* Returns true if the page is in the named well known queue. */
161 #define VM_PAGE_INQUEUE2(m, q) (VM_PAGE_GETKNOWNQUEUE2(m) == (q))
162
163 /* Sets the queue a page is on. */
164 #define VM_PAGE_SETQUEUE2(m, q) (VM_PAGE_GETQUEUE(m) = (q))
165
166 struct vpgqueues {
167 struct pglist pl;
168 int *cnt;
169 };
170
171 extern struct vpgqueues vm_page_queues[PQ_COUNT];
172 extern struct mtx vm_page_queue_free_mtx;
173
174 /*
175 * These are the flags defined for vm_page.
176 *
177 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is
178 * not under PV management but otherwise should be treated as a
179 * normal page. Pages not under PV management cannot be paged out
180 * via the object/vm_page_t because there is no knowledge of their
181 * pte mappings, nor can they be removed from their objects via
182 * the object, and such pages are also not on any PQ queue.
183 */
184 #define PG_CACHED 0x0001 /* page is cached */
185 #define PG_FREE 0x0002 /* page is free */
186 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */
187 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */
188 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */
189 #define PG_ZERO 0x0040 /* page is zeroed */
190 #define PG_REFERENCED 0x0080 /* page has been referenced */
191 #define PG_UNMANAGED 0x0800 /* No PV management for page */
192 #define PG_MARKER 0x1000 /* special queue marker page */
193 #define PG_SLAB 0x2000 /* object pointer is actually a slab */
194
195 /*
196 * Misc constants.
197 */
198 #define ACT_DECLINE 1
199 #define ACT_ADVANCE 3
200 #define ACT_INIT 5
201 #define ACT_MAX 64
202
203 #ifdef _KERNEL
204
205 #include <vm/vm_param.h>
206
207 /*
208 * Each pageable resident page falls into one of five lists:
209 *
210 * free
211 * Available for allocation now.
212 *
213 * cache
214 * Almost available for allocation. Still associated with
215 * an object, but clean and immediately freeable.
216 *
217 * hold
218 * Will become free after a pending I/O operation
219 * completes.
220 *
221 * The following lists are LRU sorted:
222 *
223 * inactive
224 * Low activity, candidates for reclamation.
225 * This is the list of pages that should be
226 * paged out next.
227 *
228 * active
229 * Pages that are "active" i.e. they have been
230 * recently referenced.
231 *
232 */
233
234 struct vnode;
235 extern int vm_page_zero_count;
236
237 extern vm_page_t vm_page_array; /* First resident page in table */
238 extern int vm_page_array_size; /* number of vm_page_t's */
239 extern long first_page; /* first physical page number */
240
241 #define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0)
242
243 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
244
245 vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa);
246
247 static __inline vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
248
249 static __inline vm_page_t
250 PHYS_TO_VM_PAGE(vm_paddr_t pa)
251 {
252 #ifdef VM_PHYSSEG_SPARSE
253 return (vm_phys_paddr_to_vm_page(pa));
254 #elif defined(VM_PHYSSEG_DENSE)
255 return (&vm_page_array[atop(pa) - first_page]);
256 #else
257 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
258 #endif
259 }
260
261 extern struct mtx vm_page_queue_mtx;
262 #define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx)
263 #define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx)
264
265 #if PAGE_SIZE == 4096
266 #define VM_PAGE_BITS_ALL 0xffu
267 #elif PAGE_SIZE == 8192
268 #define VM_PAGE_BITS_ALL 0xffffu
269 #elif PAGE_SIZE == 16384
270 #define VM_PAGE_BITS_ALL 0xffffffffu
271 #elif PAGE_SIZE == 32768
272 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
273 #endif
274
275 /* page allocation classes: */
276 #define VM_ALLOC_NORMAL 0
277 #define VM_ALLOC_INTERRUPT 1
278 #define VM_ALLOC_SYSTEM 2
279 #define VM_ALLOC_CLASS_MASK 3
280 /* page allocation flags: */
281 #define VM_ALLOC_WIRED 0x0020 /* non pageable */
282 #define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
283 #define VM_ALLOC_RETRY 0x0080 /* vm_page_grab() only */
284 #define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
285 #define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
286 #define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
287 #define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
288
289 void vm_page_flag_set(vm_page_t m, unsigned short bits);
290 void vm_page_flag_clear(vm_page_t m, unsigned short bits);
291 void vm_page_busy(vm_page_t m);
292 void vm_page_flash(vm_page_t m);
293 void vm_page_io_start(vm_page_t m);
294 void vm_page_io_finish(vm_page_t m);
295 void vm_page_hold(vm_page_t mem);
296 void vm_page_unhold(vm_page_t mem);
297 void vm_page_free(vm_page_t m);
298 void vm_page_free_zero(vm_page_t m);
299 void vm_page_dirty(vm_page_t m);
300 void vm_page_wakeup(vm_page_t m);
301
302 void vm_pageq_remove(vm_page_t m);
303
304 void vm_page_activate (vm_page_t);
305 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
306 vm_page_t vm_page_alloc_freelist(int, int);
307 struct vnode *vm_page_alloc_init(vm_page_t);
308 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
309 void vm_page_cache(vm_page_t);
310 void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
311 void vm_page_cache_remove(vm_page_t);
312 void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
313 int vm_page_try_to_cache (vm_page_t);
314 int vm_page_try_to_free (vm_page_t);
315 void vm_page_dontneed(vm_page_t);
316 void vm_page_deactivate (vm_page_t);
317 vm_page_t vm_page_find_least(vm_object_t, vm_pindex_t);
318 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
319 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
320 vm_page_t vm_page_next(vm_page_t m);
321 vm_page_t vm_page_prev(vm_page_t m);
322 void vm_page_remove (vm_page_t);
323 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
324 void vm_page_requeue(vm_page_t m);
325 void vm_page_set_valid(vm_page_t m, int base, int size);
326 void vm_page_sleep(vm_page_t m, const char *msg);
327 vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
328 vm_offset_t vm_page_startup(vm_offset_t vaddr);
329 void vm_page_unwire (vm_page_t, int);
330 void vm_page_wire (vm_page_t);
331 void vm_page_set_validclean (vm_page_t, int, int);
332 void vm_page_clear_dirty (vm_page_t, int, int);
333 void vm_page_set_invalid (vm_page_t, int, int);
334 int vm_page_is_valid (vm_page_t, int, int);
335 void vm_page_test_dirty (vm_page_t);
336 int vm_page_bits (int, int);
337 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
338 void vm_page_free_toq(vm_page_t m);
339 void vm_page_zero_idle_wakeup(void);
340 void vm_page_cowfault (vm_page_t);
341 int vm_page_cowsetup(vm_page_t);
342 void vm_page_cowclear (vm_page_t);
343
344 /*
345 * vm_page_sleep_if_busy:
346 *
347 * Sleep and release the page queues lock if VPO_BUSY is set or,
348 * if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the
349 * thread slept and the page queues lock was released.
350 * Otherwise, retains the page queues lock and returns FALSE.
351 *
352 * The object containing the given page must be locked.
353 */
354 static __inline int
355 vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg)
356 {
357
358 if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) {
359 vm_page_sleep(m, msg);
360 return (TRUE);
361 }
362 return (FALSE);
363 }
364
365 /*
366 * vm_page_undirty:
367 *
368 * Set page to not be dirty. Note: does not clear pmap modify bits
369 */
370 static __inline void
371 vm_page_undirty(vm_page_t m)
372 {
373 m->dirty = 0;
374 }
375
376 #endif /* _KERNEL */
377 #endif /* !_VM_PAGE_ */
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