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/7.4/sys/vm/vm_page.h 215433 2010-11-17 18:21:29Z alc $
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 * The 'valid' and 'dirty' fields are distinct. A page may have dirty
97 * bits set without having associated valid bits set. This is used by
98 * NFS to implement piecemeal writes.
99 */
100
101 TAILQ_HEAD(pglist, vm_page);
102
103 struct vm_page {
104 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */
105 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
106 struct vm_page *left; /* splay tree link (O) */
107 struct vm_page *right; /* splay tree link (O) */
108
109 vm_object_t object; /* which object am I in (O,P)*/
110 vm_pindex_t pindex; /* offset into object (O,P) */
111 vm_paddr_t phys_addr; /* physical address of page */
112 struct md_page md; /* machine dependant stuff */
113 uint8_t queue; /* page queue index */
114 int8_t segind;
115 u_short flags; /* see below */
116 uint8_t order; /* index of the buddy queue */
117 uint8_t pool;
118 u_short cow; /* page cow mapping count */
119 u_int wire_count; /* wired down maps refs (P) */
120 short hold_count; /* page hold count */
121 u_short oflags; /* page flags (O) */
122 u_char act_count; /* page usage count */
123 u_char busy; /* page busy count (O) */
124 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
125 /* so, on normal X86 kernels, they must be at least 8 bits wide */
126 #if PAGE_SIZE == 4096
127 u_char valid; /* map of valid DEV_BSIZE chunks (O) */
128 u_char dirty; /* map of dirty DEV_BSIZE chunks */
129 #elif PAGE_SIZE == 8192
130 u_short valid; /* map of valid DEV_BSIZE chunks (O) */
131 u_short dirty; /* map of dirty DEV_BSIZE chunks */
132 #elif PAGE_SIZE == 16384
133 u_int valid; /* map of valid DEV_BSIZE chunks (O) */
134 u_int dirty; /* map of dirty DEV_BSIZE chunks */
135 #elif PAGE_SIZE == 32768
136 u_long valid; /* map of valid DEV_BSIZE chunks (O) */
137 u_long dirty; /* map of dirty DEV_BSIZE chunks */
138 #endif
139 };
140
141 /*
142 * Page flags stored in oflags:
143 *
144 * Access to these page flags is synchronized by the lock on the object
145 * containing the page (O).
146 */
147 #define VPO_BUSY 0x0001 /* page is in transit */
148 #define VPO_WANTED 0x0002 /* someone is waiting for page */
149 #define VPO_CLEANCHK 0x0100 /* page will be checked for cleaning */
150 #define VPO_SWAPINPROG 0x0200 /* swap I/O in progress on page */
151 #define VPO_NOSYNC 0x0400 /* do not collect for syncer */
152
153 /* Make sure that u_long is at least 64 bits when PAGE_SIZE is 32K. */
154 #if PAGE_SIZE == 32768
155 #ifdef CTASSERT
156 CTASSERT(sizeof(u_long) >= 8);
157 #endif
158 #endif
159
160 #define PQ_NONE 0
161 #define PQ_INACTIVE 1
162 #define PQ_ACTIVE 2
163 #define PQ_HOLD 3
164 #define PQ_COUNT 4
165
166 /* Returns the real queue a page is on. */
167 #define VM_PAGE_GETQUEUE(m) ((m)->queue)
168
169 /* Returns the well known queue a page is on. */
170 #define VM_PAGE_GETKNOWNQUEUE2(m) VM_PAGE_GETQUEUE(m)
171
172 /* Returns true if the page is in the named well known queue. */
173 #define VM_PAGE_INQUEUE2(m, q) (VM_PAGE_GETKNOWNQUEUE2(m) == (q))
174
175 /* Sets the queue a page is on. */
176 #define VM_PAGE_SETQUEUE2(m, q) (VM_PAGE_GETQUEUE(m) = (q))
177
178 struct vpgqueues {
179 struct pglist pl;
180 int *cnt;
181 };
182
183 extern struct vpgqueues vm_page_queues[PQ_COUNT];
184 extern struct mtx vm_page_queue_free_mtx;
185
186 /*
187 * These are the flags defined for vm_page.
188 *
189 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is
190 * not under PV management but otherwise should be treated as a
191 * normal page. Pages not under PV management cannot be paged out
192 * via the object/vm_page_t because there is no knowledge of their
193 * pte mappings, nor can they be removed from their objects via
194 * the object, and such pages are also not on any PQ queue.
195 */
196 #define PG_CACHED 0x0001 /* page is cached */
197 #define PG_FREE 0x0002 /* page is free */
198 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */
199 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */
200 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */
201 #define PG_ZERO 0x0040 /* page is zeroed */
202 #define PG_REFERENCED 0x0080 /* page has been referenced */
203 #define PG_UNMANAGED 0x0800 /* No PV management for page */
204 #define PG_MARKER 0x1000 /* special queue marker page */
205 #define PG_SLAB 0x2000 /* object pointer is actually a slab */
206
207 /*
208 * Misc constants.
209 */
210 #define ACT_DECLINE 1
211 #define ACT_ADVANCE 3
212 #define ACT_INIT 5
213 #define ACT_MAX 64
214
215 #ifdef _KERNEL
216
217 #include <vm/vm_param.h>
218
219 /*
220 * Each pageable resident page falls into one of five lists:
221 *
222 * free
223 * Available for allocation now.
224 *
225 * cache
226 * Almost available for allocation. Still associated with
227 * an object, but clean and immediately freeable.
228 *
229 * hold
230 * Will become free after a pending I/O operation
231 * completes.
232 *
233 * The following lists are LRU sorted:
234 *
235 * inactive
236 * Low activity, candidates for reclamation.
237 * This is the list of pages that should be
238 * paged out next.
239 *
240 * active
241 * Pages that are "active" i.e. they have been
242 * recently referenced.
243 *
244 */
245
246 extern int vm_page_zero_count;
247
248 extern vm_page_t vm_page_array; /* First resident page in table */
249 extern int vm_page_array_size; /* number of vm_page_t's */
250 extern long first_page; /* first physical page number */
251
252 #define VM_PAGE_IS_FREE(m) (((m)->flags & PG_FREE) != 0)
253
254 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
255
256 vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa);
257
258 static __inline vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
259
260 static __inline vm_page_t
261 PHYS_TO_VM_PAGE(vm_paddr_t pa)
262 {
263 #ifdef VM_PHYSSEG_SPARSE
264 return (vm_phys_paddr_to_vm_page(pa));
265 #elif defined(VM_PHYSSEG_DENSE)
266 return (&vm_page_array[atop(pa) - first_page]);
267 #else
268 #error "Either VM_PHYSSEG_DENSE or VM_PHYSSEG_SPARSE must be defined."
269 #endif
270 }
271
272 extern struct mtx vm_page_queue_mtx;
273 #define vm_page_lock_queues() mtx_lock(&vm_page_queue_mtx)
274 #define vm_page_unlock_queues() mtx_unlock(&vm_page_queue_mtx)
275
276 #if PAGE_SIZE == 4096
277 #define VM_PAGE_BITS_ALL 0xffu
278 #elif PAGE_SIZE == 8192
279 #define VM_PAGE_BITS_ALL 0xffffu
280 #elif PAGE_SIZE == 16384
281 #define VM_PAGE_BITS_ALL 0xffffffffu
282 #elif PAGE_SIZE == 32768
283 #define VM_PAGE_BITS_ALL 0xfffffffffffffffflu
284 #endif
285
286 /* page allocation classes: */
287 #define VM_ALLOC_NORMAL 0
288 #define VM_ALLOC_INTERRUPT 1
289 #define VM_ALLOC_SYSTEM 2
290 #define VM_ALLOC_CLASS_MASK 3
291 /* page allocation flags: */
292 #define VM_ALLOC_WIRED 0x0020 /* non pageable */
293 #define VM_ALLOC_ZERO 0x0040 /* Try to obtain a zeroed page */
294 #define VM_ALLOC_RETRY 0x0080 /* vm_page_grab() only */
295 #define VM_ALLOC_NOOBJ 0x0100 /* No associated object */
296 #define VM_ALLOC_NOBUSY 0x0200 /* Do not busy the page */
297 #define VM_ALLOC_IFCACHED 0x0400 /* Fail if the page is not cached */
298 #define VM_ALLOC_IFNOTCACHED 0x0800 /* Fail if the page is cached */
299
300 void vm_page_flag_set(vm_page_t m, unsigned short bits);
301 void vm_page_flag_clear(vm_page_t m, unsigned short bits);
302 void vm_page_busy(vm_page_t m);
303 void vm_page_flash(vm_page_t m);
304 void vm_page_io_start(vm_page_t m);
305 void vm_page_io_finish(vm_page_t m);
306 void vm_page_hold(vm_page_t mem);
307 void vm_page_unhold(vm_page_t mem);
308 void vm_page_free(vm_page_t m);
309 void vm_page_free_zero(vm_page_t m);
310 void vm_page_dirty(vm_page_t m);
311 void vm_page_wakeup(vm_page_t m);
312
313 void vm_pageq_remove(vm_page_t m);
314
315 void vm_page_activate (vm_page_t);
316 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
317 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
318 void vm_page_cache (register vm_page_t);
319 void vm_page_cache_free(vm_object_t, vm_pindex_t, vm_pindex_t);
320 void vm_page_cache_remove(vm_page_t);
321 void vm_page_cache_transfer(vm_object_t, vm_pindex_t, vm_object_t);
322 int vm_page_try_to_cache (vm_page_t);
323 int vm_page_try_to_free (vm_page_t);
324 void vm_page_dontneed (register vm_page_t);
325 void vm_page_deactivate (vm_page_t);
326 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
327 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
328 vm_page_t vm_page_next(vm_page_t m);
329 vm_page_t vm_page_prev(vm_page_t m);
330 void vm_page_remove (vm_page_t);
331 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
332 void vm_page_requeue(vm_page_t m);
333 void vm_page_sleep(vm_page_t m, const char *msg);
334 vm_page_t vm_page_splay(vm_pindex_t, vm_page_t);
335 vm_offset_t vm_page_startup(vm_offset_t vaddr);
336 void vm_page_unwire (vm_page_t, int);
337 void vm_page_wire (vm_page_t);
338 void vm_page_set_validclean (vm_page_t, int, int);
339 void vm_page_clear_dirty (vm_page_t, int, int);
340 void vm_page_set_invalid (vm_page_t, int, int);
341 int vm_page_is_valid (vm_page_t, int, int);
342 void vm_page_test_dirty (vm_page_t);
343 int vm_page_bits (int, int);
344 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
345 void vm_page_free_toq(vm_page_t m);
346 void vm_page_zero_idle_wakeup(void);
347 void vm_page_cowfault (vm_page_t);
348 int vm_page_cowsetup(vm_page_t);
349 void vm_page_cowclear (vm_page_t);
350
351 /*
352 * vm_page_sleep_if_busy:
353 *
354 * Sleep and release the page queues lock if VPO_BUSY is set or,
355 * if also_m_busy is TRUE, busy is non-zero. Returns TRUE if the
356 * thread slept and the page queues lock was released.
357 * Otherwise, retains the page queues lock and returns FALSE.
358 *
359 * The object containing the given page must be locked.
360 */
361 static __inline int
362 vm_page_sleep_if_busy(vm_page_t m, int also_m_busy, const char *msg)
363 {
364
365 if ((m->oflags & VPO_BUSY) || (also_m_busy && m->busy)) {
366 vm_page_sleep(m, msg);
367 return (TRUE);
368 }
369 return (FALSE);
370 }
371
372 /*
373 * vm_page_undirty:
374 *
375 * Set page to not be dirty. Note: does not clear pmap modify bits
376 */
377 static __inline void
378 vm_page_undirty(vm_page_t m)
379 {
380 m->dirty = 0;
381 }
382
383 #endif /* _KERNEL */
384 #endif /* !_VM_PAGE_ */
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