osfmk/vm/vm_page.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990,1989,1988 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52 /*
  53  *      File:   vm/vm_page.h
  54  *      Author: Avadis Tevanian, Jr., Michael Wayne Young
  55  *      Date:   1985
  56  *
  57  *      Resident memory system definitions.
  58  */
  59
  60 #ifndef _VM_VM_PAGE_H_
  61 #define _VM_VM_PAGE_H_
  62
  63 #include <mach/boolean.h>
  64 #include <mach/vm_prot.h>
  65 #include <mach/vm_param.h>
  66 #include <vm/vm_object.h>
  67 #include <kern/queue.h>
  68 #include <kern/lock.h>
  69
  70 #include <kern/macro_help.h>
  71
  72 /*
  73  * Each page entered on the inactive queue obtains a ticket from a
  74  * particular ticket roll.  Pages granted tickets from a particular
  75  * roll  generally flow through the queue as a group.  In this way when a
  76  * page with a ticket from a particular roll is pulled from the top of the
  77  * queue it is extremely likely that the pages near the top will have tickets
  78  * from the same or adjacent rolls.  In this way the proximity to the top
  79  * of the queue can be loosely ascertained by determining the identity of
  80  * the roll the pages ticket came from.
  81  */
  82
  83
  84 extern int      vm_page_ticket_roll;
  85 extern int      vm_page_ticket;
  86
  87 #define VM_PAGE_TICKETS_IN_ROLL  512
  88 #define VM_PAGE_TICKET_ROLL_IDS  16
  89
  90 /*
  91  *      Management of resident (logical) pages.
  92  *
  93  *      A small structure is kept for each resident
  94  *      page, indexed by page number.  Each structure
  95  *      is an element of several lists:
  96  *
  97  *              A hash table bucket used to quickly
  98  *              perform object/offset lookups
  99  *
 100  *              A list of all pages for a given object,
 101  *              so they can be quickly deactivated at
 102  *              time of deallocation.
 103  *
 104  *              An ordered list of pages due for pageout.
 105  *
 106  *      In addition, the structure contains the object
 107  *      and offset to which this page belongs (for pageout),
 108  *      and sundry status bits.
 109  *
 110  *      Fields in this structure are locked either by the lock on the
 111  *      object that the page belongs to (O) or by the lock on the page
 112  *      queues (P).  [Some fields require that both locks be held to
 113  *      change that field; holding either lock is sufficient to read.]
 114  */
 115
 116 struct vm_page {
 117         queue_chain_t   pageq;          /* queue info for FIFO
 118                                          * queue or free list (P) */
 119         queue_chain_t   listq;          /* all pages in same object (O) */
 120         struct vm_page  *next;          /* VP bucket link (O) */
 121
 122         vm_object_t     object;         /* which object am I in (O&P) */
 123         vm_object_offset_t offset;      /* offset into that object (O,P) */
 124
 125         unsigned int    wire_count:16,  /* how many wired down maps use me? (O&P) */
 126                         page_ticket:4,  /* age of the page on the       */
 127                                         /* inactive queue.                  */
 128         /* boolean_t */ inactive:1,     /* page is in inactive list (P) */
 129                         active:1,       /* page is in active list (P) */
 130                         laundry:1,      /* page is being cleaned now (P)*/
 131                         free:1,         /* page is on free list (P) */
 132                         reference:1,    /* page has been used (P) */
 133                         pageout:1,      /* page wired & busy for pageout (P) */
 134                         gobbled:1,      /* page used internally (P) */
 135                         private:1,      /* Page should not be returned to
 136                                          *  the free list (O) */
 137                         :0;
 138
 139         unsigned int
 140                         page_error:8,   /* error from I/O operations */
 141         /* boolean_t */ busy:1,         /* page is in transit (O) */
 142                         wanted:1,       /* someone is waiting for page (O) */
 143                         tabled:1,       /* page is in VP table (O) */
 144                         fictitious:1,   /* Physical page doesn't exist (O) */
 145                         no_isync:1,     /* page has not been instruction synced */
 146                         absent:1,       /* Data has been requested, but is
 147                                          *  not yet available (O) */
 148                         error:1,        /* Data manager was unable to provide
 149                                          *  data due to error (O) */
 150                         dirty:1,        /* Page must be cleaned (O) */
 151                         cleaning:1,     /* Page clean has begun (O) */
 152                         precious:1,     /* Page is precious; data must be
 153                                          *  returned even if clean (O) */
 154                         clustered:1,    /* page is not the faulted page (O) */
 155                         overwriting:1,  /* Request to unlock has been made
 156                                          * without having data. (O)
 157                                          * [See vm_fault_page_overwrite] */
 158                         restart:1,      /* Page was pushed higher in shadow
 159                                            chain by copy_call-related pagers;
 160                                            start again at top of chain */
 161                         lock_supplied:1,/* protection supplied by pager (O) */
 162         /* vm_prot_t */ page_lock:3,    /* Uses prohibited by pager (O) */
 163         /* vm_prot_t */ unlock_request:3,/* Outstanding unlock request (O) */
 164                         unusual:1,      /* Page is absent, error, restart or
 165                                            page locked */
 166                         discard_request:1,/* a memory_object_discard_request()
 167                                            * has been sent */
 168                         list_req_pending:1, /* pagein/pageout alt mechanism */
 169                                             /* allows creation of list      */
 170                                             /* requests on pages that are   */
 171                                             /* actively being paged.        */
 172                         dump_cleaning:1;   /* set by the pageout daemon when */
 173                                            /* a page being cleaned is       */
 174                                            /* encountered and targeted as   */
 175                                            /* a pageout candidate           */
 176         /* we've used up all 32 bits */
 177
 178         vm_offset_t     phys_addr;      /* Physical address of page, passed
 179                                          *  to pmap_enter (read-only) */
 180 };
 181
 182 typedef struct vm_page  *vm_page_t;
 183
 184 #define VM_PAGE_NULL            ((vm_page_t) 0)
 185 #define NEXT_PAGE(m)    ((vm_page_t) (m)->pageq.next)
 186
 187 /*
 188  * XXX  The unusual bit should not be necessary.  Most of the bit
 189  * XXX  fields above really want to be masks.
 190  */
 191
 192 /*
 193  *      For debugging, this macro can be defined to perform
 194  *      some useful check on a page structure.
 195  */
 196
 197 #define VM_PAGE_CHECK(mem)
 198
 199 /*
 200  *      Each pageable resident page falls into one of three lists:
 201  *
 202  *      free
 203  *              Available for allocation now.
 204  *      inactive
 205  *              Not referenced in any map, but still has an
 206  *              object/offset-page mapping, and may be dirty.
 207  *              This is the list of pages that should be
 208  *              paged out next.
 209  *      active
 210  *              A list of pages which have been placed in
 211  *              at least one physical map.  This list is
 212  *              ordered, in LRU-like fashion.
 213  */
 214
 215 extern
 216 vm_page_t       vm_page_queue_free;     /* memory free queue */
 217 extern
 218 vm_page_t       vm_page_queue_fictitious;       /* fictitious free queue */
 219 extern
 220 queue_head_t    vm_page_queue_active;   /* active memory queue */
 221 extern
 222 queue_head_t    vm_page_queue_inactive; /* inactive memory queue */
 223
 224 extern
 225 vm_offset_t     first_phys_addr;        /* physical address for first_page */
 226 extern
 227 vm_offset_t     last_phys_addr;         /* physical address for last_page */
 228
 229 extern
 230 int     vm_page_free_count;     /* How many pages are free? */
 231 extern
 232 int     vm_page_fictitious_count;/* How many fictitious pages are free? */
 233 extern
 234 int     vm_page_active_count;   /* How many pages are active? */
 235 extern
 236 int     vm_page_inactive_count; /* How many pages are inactive? */
 237 extern
 238 int     vm_page_wire_count;     /* How many pages are wired? */
 239 extern
 240 int     vm_page_free_target;    /* How many do we want free? */
 241 extern
 242 int     vm_page_free_min;       /* When to wakeup pageout */
 243 extern
 244 int     vm_page_inactive_target;/* How many do we want inactive? */
 245 extern
 246 int     vm_page_free_reserved;  /* How many pages reserved to do pageout */
 247 extern
 248 int     vm_page_laundry_count;  /* How many pages being laundered? */
 249
 250 decl_mutex_data(,vm_page_queue_lock)
 251                                 /* lock on active and inactive page queues */
 252 decl_mutex_data(,vm_page_queue_free_lock)
 253                                 /* lock on free page queue */
 254 decl_simple_lock_data(extern,vm_page_preppin_lock)      /* lock for prep/pin */
 255
 256 extern unsigned int     vm_page_free_wanted;
 257                                 /* how many threads are waiting for memory */
 258
 259 extern vm_offset_t      vm_page_fictitious_addr;
 260                                 /* (fake) phys_addr of fictitious pages */
 261
 262 /*
 263  * Prototypes for functions exported by this module.
 264  */
 265 extern void             vm_page_bootstrap(
 266                                         vm_offset_t     *startp,
 267                                         vm_offset_t     *endp);
 268
 269 extern void             vm_page_module_init(void);
 270
 271 extern void             vm_page_create(
 272                                         vm_offset_t     start,
 273                                         vm_offset_t     end);
 274
 275 extern vm_page_t        vm_page_lookup(
 276                                         vm_object_t             object,
 277                                         vm_object_offset_t      offset);
 278
 279 extern vm_page_t        vm_page_grab_fictitious(void);
 280
 281 extern void             vm_page_release_fictitious(
 282                                         vm_page_t page);
 283
 284 extern boolean_t        vm_page_convert(
 285                                         vm_page_t       page);
 286
 287 extern void             vm_page_more_fictitious(void);
 288
 289 extern int              vm_pool_low(void);
 290
 291 extern vm_page_t        vm_page_grab(void);
 292
 293 extern void             vm_page_release(
 294                                         vm_page_t       page);
 295
 296 extern void             vm_page_release_limbo(
 297                                         vm_page_t       page);
 298
 299 extern void             vm_page_limbo_exchange(
 300                                         vm_page_t       limbo_m,
 301                                         vm_page_t       new_m);
 302
 303 extern boolean_t        vm_page_wait(
 304                                         int             interruptible );
 305
 306 extern vm_page_t        vm_page_alloc(
 307                                         vm_object_t             object,
 308                                         vm_object_offset_t      offset);
 309
 310 extern void             vm_page_init(
 311                                         vm_page_t       page,
 312                                         vm_offset_t     phys_addr);
 313
 314 extern void             vm_page_free(
 315                                         vm_page_t       page);
 316
 317 extern void             vm_page_activate(
 318                                         vm_page_t       page);
 319
 320 extern void             vm_page_deactivate(
 321                                         vm_page_t       page);
 322
 323 extern void             vm_page_rename(
 324                                         vm_page_t               page,
 325                                         vm_object_t             new_object,
 326                                         vm_object_offset_t      new_offset);
 327
 328 extern void             vm_page_insert(
 329                                         vm_page_t               page,
 330                                         vm_object_t             object,
 331                                         vm_object_offset_t      offset);
 332
 333 extern void             vm_page_replace(
 334                                         vm_page_t               mem,
 335                                         vm_object_t             object,
 336                                         vm_object_offset_t      offset);
 337
 338 extern void             vm_page_remove(
 339                                         vm_page_t       page);
 340
 341 extern void             vm_page_zero_fill(
 342                                         vm_page_t       page);
 343
 344 extern void             vm_page_part_zero_fill(
 345                                         vm_page_t       m,
 346                                         vm_offset_t     m_pa,
 347                                         vm_size_t       len);
 348
 349 extern void             vm_page_copy(
 350                                         vm_page_t       src_page,
 351                                         vm_page_t       dest_page);
 352
 353 extern void             vm_page_part_copy(
 354                                         vm_page_t       src_m,
 355                                         vm_offset_t     src_pa,
 356                                         vm_page_t       dst_m,
 357                                         vm_offset_t     dst_pa,
 358                                         vm_size_t       len);
 359
 360 extern void             vm_page_wire(
 361                                         vm_page_t       page);
 362
 363 extern void             vm_page_unwire(
 364                                         vm_page_t       page);
 365
 366 extern void             vm_set_page_size(void);
 367
 368 extern void             vm_page_gobble(
 369                                         vm_page_t      page);
 370
 371 /*
 372  *      Functions implemented as macros. m->wanted and m->busy are
 373  *      protected by the object lock.
 374  */
 375
 376 #define PAGE_ASSERT_WAIT(m, interruptible)                      \
 377                 MACRO_BEGIN                                     \
 378                 (m)->wanted = TRUE;                             \
 379                 assert_wait((event_t) (m), (interruptible));    \
 380                 MACRO_END
 381
 382 #define PAGE_WAKEUP_DONE(m)                                     \
 383                 MACRO_BEGIN                                     \
 384                 (m)->busy = FALSE;                              \
 385                 if ((m)->wanted) {                              \
 386                         (m)->wanted = FALSE;                    \
 387                         thread_wakeup((event_t) (m));           \
 388                 }                                               \
 389                 MACRO_END
 390
 391 #define PAGE_WAKEUP(m)                                          \
 392                 MACRO_BEGIN                                     \
 393                 if ((m)->wanted) {                              \
 394                         (m)->wanted = FALSE;                    \
 395                         thread_wakeup((event_t) (m));           \
 396                 }                                               \
 397                 MACRO_END
 398
 399 #define VM_PAGE_FREE(p)                         \
 400                 MACRO_BEGIN                     \
 401                 vm_page_lock_queues();          \
 402                 vm_page_free(p);                \
 403                 vm_page_unlock_queues();        \
 404                 MACRO_END
 405
 406 #define VM_PAGE_GRAB_FICTITIOUS(M)                                      \
 407                 MACRO_BEGIN                                             \
 408                 while ((M = vm_page_grab_fictitious()) == VM_PAGE_NULL) \
 409                         vm_page_more_fictitious();                      \
 410                 MACRO_END
 411
 412 #define VM_PAGE_THROTTLED()                                             \
 413                 (vm_page_free_count < (vm_page_free_target -            \
 414                  ((vm_page_free_target-vm_page_free_min)>>2)))
 415
 416 #define VM_PAGE_WAIT()          ((void)vm_page_wait(THREAD_UNINT))
 417
 418 #define vm_page_lock_queues()   mutex_lock(&vm_page_queue_lock)
 419 #define vm_page_unlock_queues() mutex_unlock(&vm_page_queue_lock)
 420 #define vm_page_pin_lock()      simple_lock(&vm_page_preppin_lock)
 421 #define vm_page_pin_unlock()    simple_unlock(&vm_page_preppin_lock)
 422
 423 #define VM_PAGE_QUEUES_REMOVE(mem)                              \
 424         MACRO_BEGIN                                             \
 425         if (mem->active) {                                      \
 426                 assert(!mem->inactive);                         \
 427                 queue_remove(&vm_page_queue_active,             \
 428                         mem, vm_page_t, pageq);                 \
 429                 mem->active = FALSE;                            \
 430                 if (!mem->fictitious)                           \
 431                         vm_page_active_count--;                 \
 432         }                                                       \
 433                                                                 \
 434         if (mem->inactive) {                                    \
 435                 assert(!mem->active);                           \
 436                 queue_remove(&vm_page_queue_inactive,           \
 437                         mem, vm_page_t, pageq);                 \
 438                 mem->inactive = FALSE;                          \
 439                 if (!mem->fictitious)                           \
 440                         vm_page_inactive_count--;               \
 441         }                                                       \
 442         MACRO_END
 443
 444 #endif  /* _VM_VM_PAGE_H_ */