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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * from: @(#)vm_page.h 8.2 (Berkeley) 12/13/93
39 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40 * All rights reserved.
42 * Authors: Avadis Tevanian, Jr., Michael Wayne Young
44 * Permission to use, copy, modify and distribute this software and
45 * its documentation is hereby granted, provided that both the copyright
46 * notice and this permission notice appear in all copies of the
47 * software, derivative works or modified versions, and any portions
48 * thereof, and that both notices appear in supporting documentation.
50 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
51 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
52 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54 * Carnegie Mellon requests users of this software to return to
56 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
57 * School of Computer Science
58 * Carnegie Mellon University
59 * Pittsburgh PA 15213-3890
61 * any improvements or extensions that they make and grant Carnegie the
62 * rights to redistribute these changes.
64 * $FreeBSD: src/sys/vm/vm_page.h,v 1.75.2.8 2002/03/06 01:07:09 dillon Exp $
68 * Resident memory system definitions.
74 #if !defined(KLD_MODULE)
75 #include "opt_vmpage.h"
79 #include <machine/atomic.h>
82 * Management of resident (logical) pages.
84 * A small structure is kept for each resident
85 * page, indexed by page number. Each structure
86 * is an element of several lists:
88 * A hash table bucket used to quickly
89 * perform object/offset lookups
91 * A list of all pages for a given object,
92 * so they can be quickly deactivated at
93 * time of deallocation.
95 * An ordered list of pages due for pageout.
97 * In addition, the structure contains the object
98 * and offset to which this page belongs (for pageout),
99 * and sundry status bits.
101 * Fields in this structure are locked either by the lock on the
102 * object that the page belongs to (O) or by the lock on the page
105 * The 'valid' and 'dirty' fields are distinct. A page may have dirty
106 * bits set without having associated valid bits set. This is used by
107 * NFS to implement piecemeal writes.
110 TAILQ_HEAD(pglist, vm_page);
113 TAILQ_ENTRY(vm_page) pageq; /* queue info for FIFO queue or free list (P) */
114 struct vm_page *hnext; /* hash table link (O,P) */
115 TAILQ_ENTRY(vm_page) listq; /* pages in same object (O) */
117 vm_object_t object; /* which object am I in (O,P)*/
118 vm_pindex_t pindex; /* offset into object (O,P) */
119 vm_offset_t phys_addr; /* physical address of page */
120 struct md_page md; /* machine dependant stuff */
121 u_short queue; /* page queue index */
122 u_short flags, /* see below */
124 u_short wire_count; /* wired down maps refs (P) */
125 short hold_count; /* page hold count */
126 u_char act_count; /* page usage count */
127 u_char busy; /* page busy count */
128 /* NOTE that these must support one bit per DEV_BSIZE in a page!!! */
129 /* so, on normal X86 kernels, they must be at least 8 bits wide */
130 #if PAGE_SIZE == 4096
131 u_char valid; /* map of valid DEV_BSIZE chunks */
132 u_char dirty; /* map of dirty DEV_BSIZE chunks */
133 #elif PAGE_SIZE == 8192
134 u_short valid; /* map of valid DEV_BSIZE chunks */
135 u_short dirty; /* map of dirty DEV_BSIZE chunks */
140 * note: currently use SWAPBLK_NONE as an absolute value rather then
144 #define SWAPBLK_MASK ((daddr_t)((u_daddr_t)-1 >> 1)) /* mask */
145 #define SWAPBLK_NONE ((daddr_t)((u_daddr_t)SWAPBLK_MASK + 1))/* flag */
147 #if !defined(KLD_MODULE)
150 * Page coloring parameters
152 /* Each of PQ_FREE, and PQ_CACHE have PQ_HASH_SIZE entries */
154 /* Backward compatibility for existing PQ_*CACHE config options. */
155 #if !defined(PQ_CACHESIZE)
156 #if defined(PQ_HUGECACHE)
157 #define PQ_CACHESIZE 1024
158 #elif defined(PQ_LARGECACHE)
159 #define PQ_CACHESIZE 512
160 #elif defined(PQ_MEDIUMCACHE)
161 #define PQ_CACHESIZE 256
162 #elif defined(PQ_NORMALCACHE)
163 #define PQ_CACHESIZE 64
164 #elif defined(PQ_NOOPT)
165 #define PQ_CACHESIZE 0
167 #define PQ_CACHESIZE 128
171 #if PQ_CACHESIZE >= 1024
172 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */
173 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */
174 #define PQ_L2_SIZE 256 /* A number of colors opt for 1M cache */
176 #elif PQ_CACHESIZE >= 512
177 #define PQ_PRIME1 31 /* Prime number somewhat less than PQ_HASH_SIZE */
178 #define PQ_PRIME2 23 /* Prime number somewhat less than PQ_HASH_SIZE */
179 #define PQ_L2_SIZE 128 /* A number of colors opt for 512K cache */
181 #elif PQ_CACHESIZE >= 256
182 #define PQ_PRIME1 13 /* Prime number somewhat less than PQ_HASH_SIZE */
183 #define PQ_PRIME2 7 /* Prime number somewhat less than PQ_HASH_SIZE */
184 #define PQ_L2_SIZE 64 /* A number of colors opt for 256K cache */
186 #elif PQ_CACHESIZE >= 128
187 #define PQ_PRIME1 9 /* Produces a good PQ_L2_SIZE/3 + PQ_PRIME1 */
188 #define PQ_PRIME2 5 /* Prime number somewhat less than PQ_HASH_SIZE */
189 #define PQ_L2_SIZE 32 /* A number of colors opt for 128k cache */
191 #elif PQ_CACHESIZE >= 64
192 #define PQ_PRIME1 5 /* Prime number somewhat less than PQ_HASH_SIZE */
193 #define PQ_PRIME2 3 /* Prime number somewhat less than PQ_HASH_SIZE */
194 #define PQ_L2_SIZE 16 /* A reasonable number of colors (opt for 64K cache) */
197 #define PQ_PRIME1 1 /* Disable page coloring. */
203 #define PQ_L2_MASK (PQ_L2_SIZE - 1)
207 #define PQ_INACTIVE (1 + 1*PQ_L2_SIZE)
208 #define PQ_ACTIVE (2 + 1*PQ_L2_SIZE)
209 #define PQ_CACHE (3 + 1*PQ_L2_SIZE)
210 #define PQ_HOLD (3 + 2*PQ_L2_SIZE)
211 #define PQ_COUNT (4 + 2*PQ_L2_SIZE)
219 extern struct vpgqueues vm_page_queues[PQ_COUNT];
224 * These are the flags defined for vm_page.
226 * Note: PG_FILLED and PG_DIRTY are added for the filesystems.
228 * Note: PG_UNMANAGED (used by OBJT_PHYS) indicates that the page is
229 * not under PV management but otherwise should be treated as a
230 * normal page. Pages not under PV management cannot be paged out
231 * via the object/vm_page_t because there is no knowledge of their
232 * pte mappings, nor can they be removed from their objects via
233 * the object, and such pages are also not on any PQ queue.
235 #define PG_BUSY 0x0001 /* page is in transit (O) */
236 #define PG_WANTED 0x0002 /* someone is waiting for page (O) */
237 #define PG_WINATCFLS 0x0004 /* flush dirty page on inactive q */
238 #define PG_FICTITIOUS 0x0008 /* physical page doesn't exist (O) */
239 #define PG_WRITEABLE 0x0010 /* page is mapped writeable */
240 #define PG_MAPPED 0x0020 /* page is mapped */
241 #define PG_ZERO 0x0040 /* page is zeroed */
242 #define PG_REFERENCED 0x0080 /* page has been referenced */
243 #define PG_CLEANCHK 0x0100 /* page will be checked for cleaning */
244 #define PG_SWAPINPROG 0x0200 /* swap I/O in progress on page */
245 #define PG_NOSYNC 0x0400 /* do not collect for syncer */
246 #define PG_UNMANAGED 0x0800 /* No PV management for page */
247 #define PG_MARKER 0x1000 /* special queue marker page */
253 #define ACT_DECLINE 1
254 #define ACT_ADVANCE 3
257 #define PFCLUSTER_BEHIND 3
258 #define PFCLUSTER_AHEAD 3
262 * Each pageable resident page falls into one of four lists:
265 * Available for allocation now.
267 * The following are all LRU sorted:
270 * Almost available for allocation. Still in an
271 * object, but clean and immediately freeable at
272 * non-interrupt times.
275 * Low activity, candidates for reclamation.
276 * This is the list of pages that should be
280 * Pages that are "active" i.e. they have been
281 * recently referenced.
284 * Pages that are really free and have been pre-zeroed
288 extern int vm_page_zero_count;
290 extern vm_page_t vm_page_array; /* First resident page in table */
291 extern int vm_page_array_size; /* number of vm_page_t's */
292 extern long first_page; /* first physical page number */
294 #define VM_PAGE_TO_PHYS(entry) ((entry)->phys_addr)
296 #define PHYS_TO_VM_PAGE(pa) \
297 (&vm_page_array[atop(pa) - first_page ])
300 * Functions implemented as macros
304 vm_page_flag_set(vm_page_t m, unsigned int bits)
306 atomic_set_short(&(m)->flags, bits);
310 vm_page_flag_clear(vm_page_t m, unsigned int bits)
312 atomic_clear_short(&(m)->flags, bits);
317 vm_page_assert_wait(vm_page_t m, int interruptible)
319 vm_page_flag_set(m, PG_WANTED);
320 assert_wait((int) m, interruptible);
325 vm_page_busy(vm_page_t m)
327 KASSERT((m->flags & PG_BUSY) == 0, ("vm_page_busy: page already busy!!!"));
328 vm_page_flag_set(m, PG_BUSY);
334 * wakeup anyone waiting for the page.
338 vm_page_flash(vm_page_t m)
340 if (m->flags & PG_WANTED) {
341 vm_page_flag_clear(m, PG_WANTED);
349 * clear the PG_BUSY flag and wakeup anyone waiting for the
355 vm_page_wakeup(vm_page_t m)
357 KASSERT(m->flags & PG_BUSY, ("vm_page_wakeup: page not busy!!!"));
358 vm_page_flag_clear(m, PG_BUSY);
368 vm_page_io_start(vm_page_t m)
370 atomic_add_char(&(m)->busy, 1);
374 vm_page_io_finish(vm_page_t m)
376 atomic_subtract_char(&m->busy, 1);
382 #if PAGE_SIZE == 4096
383 #define VM_PAGE_BITS_ALL 0xff
386 #if PAGE_SIZE == 8192
387 #define VM_PAGE_BITS_ALL 0xffff
390 #define VM_ALLOC_NORMAL 0
391 #define VM_ALLOC_INTERRUPT 1
392 #define VM_ALLOC_SYSTEM 2
393 #define VM_ALLOC_ZERO 3
394 #define VM_ALLOC_RETRY 0x80
396 void vm_page_unhold(vm_page_t mem);
398 void vm_page_activate (vm_page_t);
399 vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int);
400 vm_page_t vm_page_grab (vm_object_t, vm_pindex_t, int);
401 void vm_page_cache (register vm_page_t);
402 int vm_page_try_to_cache (vm_page_t);
403 int vm_page_try_to_free (vm_page_t);
404 void vm_page_dontneed (register vm_page_t);
405 static __inline void vm_page_copy (vm_page_t, vm_page_t);
406 static __inline void vm_page_free (vm_page_t);
407 static __inline void vm_page_free_zero (vm_page_t);
408 void vm_page_deactivate (vm_page_t);
409 void vm_page_insert (vm_page_t, vm_object_t, vm_pindex_t);
410 vm_page_t vm_page_lookup (vm_object_t, vm_pindex_t);
411 void vm_page_remove (vm_page_t);
412 void vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t);
413 vm_offset_t vm_page_startup (vm_offset_t, vm_offset_t, vm_offset_t);
414 vm_page_t vm_add_new_page (vm_offset_t pa);
415 void vm_page_unmanage (vm_page_t);
416 void vm_page_unwire (vm_page_t, int);
417 void vm_page_wire (vm_page_t);
418 void vm_page_unqueue (vm_page_t);
419 void vm_page_unqueue_nowakeup (vm_page_t);
420 void vm_page_set_validclean (vm_page_t, int, int);
421 void vm_page_set_dirty (vm_page_t, int, int);
422 void vm_page_clear_dirty (vm_page_t, int, int);
423 void vm_page_set_invalid (vm_page_t, int, int);
424 static __inline boolean_t vm_page_zero_fill (vm_page_t);
425 int vm_page_is_valid (vm_page_t, int, int);
426 void vm_page_test_dirty (vm_page_t);
427 int vm_page_bits (int, int);
428 vm_page_t _vm_page_list_find (int, int);
430 int vm_page_sleep(vm_page_t m, char *msg, char *busy);
431 int vm_page_asleep(vm_page_t m, char *msg, char *busy);
433 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
434 void vm_page_free_toq(vm_page_t m);
437 * Keep page from being freed by the page daemon
438 * much of the same effect as wiring, except much lower
439 * overhead and should be used only for *very* temporary
440 * holding ("wiring").
443 vm_page_hold(vm_page_t mem)
451 * Reduce the protection of a page. This routine never raises the
452 * protection and therefore can be safely called if the page is already
453 * at VM_PROT_NONE (it will be a NOP effectively ).
457 vm_page_protect(vm_page_t mem, int prot)
459 if (prot == VM_PROT_NONE) {
460 if (mem->flags & (PG_WRITEABLE|PG_MAPPED)) {
461 pmap_page_protect(mem, VM_PROT_NONE);
462 vm_page_flag_clear(mem, PG_WRITEABLE|PG_MAPPED);
464 } else if ((prot == VM_PROT_READ) && (mem->flags & PG_WRITEABLE)) {
465 pmap_page_protect(mem, VM_PROT_READ);
466 vm_page_flag_clear(mem, PG_WRITEABLE);
473 * Zero-fill the specified page.
474 * Written as a standard pagein routine, to
475 * be used by the zero-fill object.
477 static __inline boolean_t
481 pmap_zero_page(VM_PAGE_TO_PHYS(m));
488 * Copy one page to another
491 vm_page_copy(src_m, dest_m)
495 pmap_copy_page(VM_PAGE_TO_PHYS(src_m), VM_PAGE_TO_PHYS(dest_m));
496 dest_m->valid = VM_PAGE_BITS_ALL;
504 * The clearing of PG_ZERO is a temporary safety until the code can be
505 * reviewed to determine that PG_ZERO is being properly cleared on
506 * write faults or maps. PG_ZERO was previously cleared in
513 vm_page_flag_clear(m, PG_ZERO);
520 * Free a page to the zerod-pages queue
526 vm_page_flag_set(m, PG_ZERO);
531 * vm_page_sleep_busy:
533 * Wait until page is no longer PG_BUSY or (if also_m_busy is TRUE)
534 * m->busy is zero. Returns TRUE if it had to sleep ( including if
535 * it almost had to sleep and made temporary spl*() mods), FALSE
538 * This routine assumes that interrupts can only remove the busy
539 * status from a page, not set the busy status or change it from
540 * PG_BUSY to m->busy or vise versa (which would create a timing
543 * Note that being an inline, this code will be well optimized.
547 vm_page_sleep_busy(vm_page_t m, int also_m_busy, const char *msg)
549 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) {
551 if ((m->flags & PG_BUSY) || (also_m_busy && m->busy)) {
553 * Page is busy. Wait and retry.
555 vm_page_flag_set(m, PG_WANTED | PG_REFERENCED);
556 tsleep(m, PVM, msg, 0);
568 * make page all dirty
572 vm_page_dirty(vm_page_t m)
574 #if !defined(KLD_MODULE)
575 KASSERT(m->queue - m->pc != PQ_CACHE, ("vm_page_dirty: page in cache!"));
577 m->dirty = VM_PAGE_BITS_ALL;
583 * Set page to not be dirty. Note: does not clear pmap modify bits
587 vm_page_undirty(vm_page_t m)
592 #if !defined(KLD_MODULE)
594 static __inline vm_page_t
595 vm_page_list_find(int basequeue, int index, boolean_t prefer_zero)
601 m = TAILQ_LAST(&vm_page_queues[basequeue+index].pl, pglist);
603 m = TAILQ_FIRST(&vm_page_queues[basequeue+index].pl);
606 m = _vm_page_list_find(basequeue, index);
609 m = TAILQ_LAST(&vm_page_queues[basequeue].pl, pglist);
611 m = TAILQ_FIRST(&vm_page_queues[basequeue].pl);
620 #endif /* !_VM_PAGE_ */