FreeBSD/Linux Kernel Cross Reference
sys/vm/uma.h
1 /*-
2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice unmodified, this list of conditions, and the following
11 * disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD: releng/6.0/sys/vm/uma.h 148476 2005-07-28 12:10:19Z rwatson $
28 *
29 */
30
31 /*
32 * uma.h - External definitions for the Universal Memory Allocator
33 *
34 */
35
36 #ifndef VM_UMA_H
37 #define VM_UMA_H
38
39 #include <sys/param.h> /* For NULL */
40 #include <sys/malloc.h> /* For M_* */
41
42 /* User visable parameters */
43 #define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */
44
45 /* Types and type defs */
46
47 struct uma_zone;
48 /* Opaque type used as a handle to the zone */
49 typedef struct uma_zone * uma_zone_t;
50
51 /*
52 * Item constructor
53 *
54 * Arguments:
55 * item A pointer to the memory which has been allocated.
56 * arg The arg field passed to uma_zalloc_arg
57 * size The size of the allocated item
58 * flags See zalloc flags
59 *
60 * Returns:
61 * 0 on success
62 * errno on failure
63 *
64 * Discussion:
65 * The constructor is called just before the memory is returned
66 * to the user. It may block if necessary.
67 */
68 typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
69
70 /*
71 * Item destructor
72 *
73 * Arguments:
74 * item A pointer to the memory which has been allocated.
75 * size The size of the item being destructed.
76 * arg Argument passed through uma_zfree_arg
77 *
78 * Returns:
79 * Nothing
80 *
81 * Discussion:
82 * The destructor may perform operations that differ from those performed
83 * by the initializer, but it must leave the object in the same state.
84 * This IS type stable storage. This is called after EVERY zfree call.
85 */
86 typedef void (*uma_dtor)(void *mem, int size, void *arg);
87
88 /*
89 * Item initializer
90 *
91 * Arguments:
92 * item A pointer to the memory which has been allocated.
93 * size The size of the item being initialized.
94 * flags See zalloc flags
95 *
96 * Returns:
97 * 0 on success
98 * errno on failure
99 *
100 * Discussion:
101 * The initializer is called when the memory is cached in the uma zone.
102 * this should be the same state that the destructor leaves the object in.
103 */
104 typedef int (*uma_init)(void *mem, int size, int flags);
105
106 /*
107 * Item discard function
108 *
109 * Arguments:
110 * item A pointer to memory which has been 'freed' but has not left the
111 * zone's cache.
112 * size The size of the item being discarded.
113 *
114 * Returns:
115 * Nothing
116 *
117 * Discussion:
118 * This routine is called when memory leaves a zone and is returned to the
119 * system for other uses. It is the counter part to the init function.
120 */
121 typedef void (*uma_fini)(void *mem, int size);
122
123 /*
124 * What's the difference between initializing and constructing?
125 *
126 * The item is initialized when it is cached, and this is the state that the
127 * object should be in when returned to the allocator. The purpose of this is
128 * to remove some code which would otherwise be called on each allocation by
129 * utilizing a known, stable state. This differs from the constructor which
130 * will be called on EVERY allocation.
131 *
132 * For example, in the initializer you may want to initialize embeded locks,
133 * NULL list pointers, set up initial states, magic numbers, etc. This way if
134 * the object is held in the allocator and re-used it won't be necessary to
135 * re-initialize it.
136 *
137 * The constructor may be used to lock a data structure, link it on to lists,
138 * bump reference counts or total counts of outstanding structures, etc.
139 *
140 */
141
142
143 /* Function proto types */
144
145 /*
146 * Create a new uma zone
147 *
148 * Arguments:
149 * name The text name of the zone for debugging and stats, this memory
150 * should not be freed until the zone has been deallocated.
151 * size The size of the object that is being created.
152 * ctor The constructor that is called when the object is allocated
153 * dtor The destructor that is called when the object is freed.
154 * init An initializer that sets up the initial state of the memory.
155 * fini A discard function that undoes initialization done by init.
156 * ctor/dtor/init/fini may all be null, see notes above.
157 * align A bitmask that corisponds to the requested alignment
158 * eg 4 would be 0x3
159 * flags A set of parameters that control the behavior of the zone
160 *
161 * Returns:
162 * A pointer to a structure which is intended to be opaque to users of
163 * the interface. The value may be null if the wait flag is not set.
164 */
165 uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
166 uma_init uminit, uma_fini fini, int align,
167 u_int32_t flags);
168
169 /*
170 * Create a secondary uma zone
171 *
172 * Arguments:
173 * name The text name of the zone for debugging and stats, this memory
174 * should not be freed until the zone has been deallocated.
175 * ctor The constructor that is called when the object is allocated
176 * dtor The destructor that is called when the object is freed.
177 * zinit An initializer that sets up the initial state of the memory
178 * as the object passes from the Keg's slab to the Zone's cache.
179 * zfini A discard function that undoes initialization done by init
180 * as the object passes from the Zone's cache to the Keg's slab.
181 *
182 * ctor/dtor/zinit/zfini may all be null, see notes above.
183 * Note that the zinit and zfini specified here are NOT
184 * exactly the same as the init/fini specified to uma_zcreate()
185 * when creating a master zone. These zinit/zfini are called
186 * on the TRANSITION from keg to zone (and vice-versa). Once
187 * these are set, the primary zone may alter its init/fini
188 * (which are called when the object passes from VM to keg)
189 * using uma_zone_set_init/fini()) as well as its own
190 * zinit/zfini (unset by default for master zone) with
191 * uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
192 *
193 * master A reference to this zone's Master Zone (Primary Zone),
194 * which contains the backing Keg for the Secondary Zone
195 * being added.
196 *
197 * Returns:
198 * A pointer to a structure which is intended to be opaque to users of
199 * the interface. The value may be null if the wait flag is not set.
200 */
201 uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
202 uma_init zinit, uma_fini zfini, uma_zone_t master);
203
204 /*
205 * Definitions for uma_zcreate flags
206 *
207 * These flags share space with UMA_ZFLAGs in uma_int.h. Be careful not to
208 * overlap when adding new features. 0xf0000000 is in use by uma_int.h.
209 */
210 #define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by
211 physical memory XXX Not yet */
212 #define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */
213 #define UMA_ZONE_STATIC 0x0004 /* Staticly sized zone */
214 #define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation
215 off of the real memory */
216 #define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */
217 #define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */
218 #define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */
219 #define UMA_ZONE_VM 0x0080 /*
220 * Used for internal vm datastructures
221 * only.
222 */
223 #define UMA_ZONE_HASH 0x0100 /*
224 * Use a hash table instead of caching
225 * information in the vm_page.
226 */
227 #define UMA_ZONE_SECONDARY 0x0200 /* Zone is a Secondary Zone */
228 #define UMA_ZONE_REFCNT 0x0400 /* Allocate refcnts in slabs */
229 #define UMA_ZONE_MAXBUCKET 0x0800 /* Use largest buckets */
230
231 /* Definitions for align */
232 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */
233 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */
234 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */
235 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */
236 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */
237 #define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */
238
239 /*
240 * Destroys an empty uma zone. If the zone is not empty uma complains loudly.
241 *
242 * Arguments:
243 * zone The zone we want to destroy.
244 *
245 */
246 void uma_zdestroy(uma_zone_t zone);
247
248 /*
249 * Allocates an item out of a zone
250 *
251 * Arguments:
252 * zone The zone we are allocating from
253 * arg This data is passed to the ctor function
254 * flags See sys/malloc.h for available flags.
255 *
256 * Returns:
257 * A non null pointer to an initialized element from the zone is
258 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be
259 * returned if the zone is empty or the ctor failed.
260 */
261
262 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
263
264 /*
265 * Allocates an item out of a zone without supplying an argument
266 *
267 * This is just a wrapper for uma_zalloc_arg for convenience.
268 *
269 */
270 static __inline void *uma_zalloc(uma_zone_t zone, int flags);
271
272 static __inline void *
273 uma_zalloc(uma_zone_t zone, int flags)
274 {
275 return uma_zalloc_arg(zone, NULL, flags);
276 }
277
278 /*
279 * Frees an item back into the specified zone.
280 *
281 * Arguments:
282 * zone The zone the item was originally allocated out of.
283 * item The memory to be freed.
284 * arg Argument passed to the destructor
285 *
286 * Returns:
287 * Nothing.
288 */
289
290 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
291
292 /*
293 * Frees an item back to a zone without supplying an argument
294 *
295 * This is just a wrapper for uma_zfree_arg for convenience.
296 *
297 */
298 static __inline void uma_zfree(uma_zone_t zone, void *item);
299
300 static __inline void
301 uma_zfree(uma_zone_t zone, void *item)
302 {
303 uma_zfree_arg(zone, item, NULL);
304 }
305
306 /*
307 * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
308 * If you think you need to use it for a normal zone you're probably incorrect.
309 */
310
311 /*
312 * Backend page supplier routines
313 *
314 * Arguments:
315 * zone The zone that is requesting pages
316 * size The number of bytes being requested
317 * pflag Flags for these memory pages, see below.
318 * wait Indicates our willingness to block.
319 *
320 * Returns:
321 * A pointer to the alloced memory or NULL on failure.
322 */
323
324 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
325
326 /*
327 * Backend page free routines
328 *
329 * Arguments:
330 * item A pointer to the previously allocated pages
331 * size The original size of the allocation
332 * pflag The flags for the slab. See UMA_SLAB_* below
333 *
334 * Returns:
335 * None
336 */
337 typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
338
339
340
341 /*
342 * Sets up the uma allocator. (Called by vm_mem_init)
343 *
344 * Arguments:
345 * bootmem A pointer to memory used to bootstrap the system.
346 *
347 * Returns:
348 * Nothing
349 *
350 * Discussion:
351 * This memory is used for zones which allocate things before the
352 * backend page supplier can give us pages. It should be
353 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h)
354 *
355 */
356
357 void uma_startup(void *bootmem);
358
359 /*
360 * Finishes starting up the allocator. This should
361 * be called when kva is ready for normal allocs.
362 *
363 * Arguments:
364 * None
365 *
366 * Returns:
367 * Nothing
368 *
369 * Discussion:
370 * uma_startup2 is called by kmeminit() to enable us of uma for malloc.
371 */
372
373 void uma_startup2(void);
374
375 /*
376 * Reclaims unused memory for all zones
377 *
378 * Arguments:
379 * None
380 * Returns:
381 * None
382 *
383 * This should only be called by the page out daemon.
384 */
385
386 void uma_reclaim(void);
387
388 /*
389 * Switches the backing object of a zone
390 *
391 * Arguments:
392 * zone The zone to update
393 * obj The obj to use for future allocations
394 * size The size of the object to allocate
395 *
396 * Returns:
397 * 0 if kva space can not be allocated
398 * 1 if successful
399 *
400 * Discussion:
401 * A NULL object can be used and uma will allocate one for you. Setting
402 * the size will limit the amount of memory allocated to this zone.
403 *
404 */
405 struct vm_object;
406 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
407
408 /*
409 * Sets a high limit on the number of items allowed in a zone
410 *
411 * Arguments:
412 * zone The zone to limit
413 *
414 * Returns:
415 * Nothing
416 */
417 void uma_zone_set_max(uma_zone_t zone, int nitems);
418
419 /*
420 * The following two routines (uma_zone_set_init/fini)
421 * are used to set the backend init/fini pair which acts on an
422 * object as it becomes allocated and is placed in a slab within
423 * the specified zone's backing keg. These should probably not
424 * be changed once allocations have already begun and only
425 * immediately upon zone creation.
426 */
427 void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
428 void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
429
430 /*
431 * The following two routines (uma_zone_set_zinit/zfini) are
432 * used to set the zinit/zfini pair which acts on an object as
433 * it passes from the backing Keg's slab cache to the
434 * specified Zone's bucket cache. These should probably not
435 * be changed once allocations have already begun and
436 * only immediately upon zone creation.
437 */
438 void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
439 void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
440
441 /*
442 * Replaces the standard page_alloc or obj_alloc functions for this zone
443 *
444 * Arguments:
445 * zone The zone whos back end allocator is being changed.
446 * allocf A pointer to the allocation function
447 *
448 * Returns:
449 * Nothing
450 *
451 * Discussion:
452 * This could be used to implement pageable allocation, or perhaps
453 * even DMA allocators if used in conjunction with the OFFPAGE
454 * zone flag.
455 */
456
457 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
458
459 /*
460 * Used for freeing memory provided by the allocf above
461 *
462 * Arguments:
463 * zone The zone that intends to use this free routine.
464 * freef The page freeing routine.
465 *
466 * Returns:
467 * Nothing
468 */
469
470 void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
471
472 /*
473 * These flags are setable in the allocf and visable in the freef.
474 */
475 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
476 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
477 #define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
478 #define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
479 #define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */
480 /* 0x40 and 0x80 are available */
481
482 /*
483 * Used to pre-fill a zone with some number of items
484 *
485 * Arguments:
486 * zone The zone to fill
487 * itemcnt The number of items to reserve
488 *
489 * Returns:
490 * Nothing
491 *
492 * NOTE: This is blocking and should only be done at startup
493 */
494 void uma_prealloc(uma_zone_t zone, int itemcnt);
495
496 /*
497 * Used to lookup the reference counter allocated for an item
498 * from a UMA_ZONE_REFCNT zone. For UMA_ZONE_REFCNT zones,
499 * reference counters are allocated for items and stored in
500 * the underlying slab header.
501 *
502 * Arguments:
503 * zone The UMA_ZONE_REFCNT zone to which the item belongs.
504 * item The address of the item for which we want a refcnt.
505 *
506 * Returns:
507 * A pointer to a u_int32_t reference counter.
508 */
509 u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
510
511 /*
512 * Exported statistics structures to be used by user space monitoring tools.
513 * Statistics stream consusts of a uma_stream_header, followed by a series of
514 * alternative uma_type_header and uma_type_stat structures. Statistics
515 * structures
516 */
517 #define UMA_STREAM_VERSION 0x00000001
518 struct uma_stream_header {
519 u_int32_t ush_version; /* Stream format version. */
520 u_int32_t ush_maxcpus; /* Value of MAXCPU for stream. */
521 u_int32_t ush_count; /* Number of records. */
522 u_int32_t _ush_pad; /* Pad/reserved field. */
523 };
524
525 #define UTH_MAX_NAME 32
526 #define UTH_ZONE_SECONDARY 0x00000001
527 struct uma_type_header {
528 /*
529 * Static per-zone data, some extracted from the supporting keg.
530 */
531 char uth_name[UTH_MAX_NAME];
532 u_int32_t uth_align; /* Keg: alignment. */
533 u_int32_t uth_size; /* Keg: requested size of item. */
534 u_int32_t uth_rsize; /* Keg: real size of item. */
535 u_int32_t uth_maxpages; /* Keg: maximum number of pages. */
536 u_int32_t uth_limit; /* Keg: max items to allocate. */
537
538 /*
539 * Current dynamic zone/keg-derived statistics.
540 */
541 u_int32_t uth_pages; /* Keg: pages allocated. */
542 u_int32_t uth_keg_free; /* Keg: items free. */
543 u_int32_t uth_zone_free; /* Zone: items free. */
544 u_int32_t uth_bucketsize; /* Zone: desired bucket size. */
545 u_int32_t uth_zone_flags; /* Zone: flags. */
546 u_int64_t uth_allocs; /* Zone: number of allocations. */
547 u_int64_t uth_frees; /* Zone: number of frees. */
548 u_int64_t uth_fails; /* Zone: number of alloc failures. */
549 u_int64_t _uth_reserved1[3]; /* Reserved. */
550 };
551
552 struct uma_percpu_stat {
553 u_int64_t ups_allocs; /* Cache: number of alloctions. */
554 u_int64_t ups_frees; /* Cache: number of frees. */
555 u_int64_t ups_cache_free; /* Cache: free items in cache. */
556 u_int64_t _ups_reserved[5]; /* Reserved. */
557 };
558
559 #endif
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