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: head/sys/vm/uma.h 213911 2010-10-16 04:41:45Z lstewart $
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 visible parameters */
43#define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */
44
45/* Types and type defs */
46
47struct uma_zone;
48/* Opaque type used as a handle to the zone */
49typedef struct uma_zone * uma_zone_t;
50
51void zone_drain(uma_zone_t);
52
53/*
54 * Item constructor
55 *
56 * Arguments:
57 * item A pointer to the memory which has been allocated.
58 * arg The arg field passed to uma_zalloc_arg
59 * size The size of the allocated item
60 * flags See zalloc flags
61 *
62 * Returns:
63 * 0 on success
64 * errno on failure
65 *
66 * Discussion:
67 * The constructor is called just before the memory is returned
68 * to the user. It may block if necessary.
69 */
70typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
71
72/*
73 * Item destructor
74 *
75 * Arguments:
76 * item A pointer to the memory which has been allocated.
77 * size The size of the item being destructed.
78 * arg Argument passed through uma_zfree_arg
79 *
80 * Returns:
81 * Nothing
82 *
83 * Discussion:
84 * The destructor may perform operations that differ from those performed
85 * by the initializer, but it must leave the object in the same state.
86 * This IS type stable storage. This is called after EVERY zfree call.
87 */
88typedef void (*uma_dtor)(void *mem, int size, void *arg);
89
90/*
91 * Item initializer
92 *
93 * Arguments:
94 * item A pointer to the memory which has been allocated.
95 * size The size of the item being initialized.
96 * flags See zalloc flags
97 *
98 * Returns:
99 * 0 on success
100 * errno on failure
101 *
102 * Discussion:
103 * The initializer is called when the memory is cached in the uma zone.
104 * The initializer and the destructor should leave the object in the same
105 * state.
106 */
107typedef int (*uma_init)(void *mem, int size, int flags);
108
109/*
110 * Item discard function
111 *
112 * Arguments:
113 * item A pointer to memory which has been 'freed' but has not left the
114 * zone's cache.
115 * size The size of the item being discarded.
116 *
117 * Returns:
118 * Nothing
119 *
120 * Discussion:
121 * This routine is called when memory leaves a zone and is returned to the
122 * system for other uses. It is the counter-part to the init function.
123 */
124typedef void (*uma_fini)(void *mem, int size);
125
126/*
127 * What's the difference between initializing and constructing?
128 *
129 * The item is initialized when it is cached, and this is the state that the
130 * object should be in when returned to the allocator. The purpose of this is
131 * to remove some code which would otherwise be called on each allocation by
132 * utilizing a known, stable state. This differs from the constructor which
133 * will be called on EVERY allocation.
134 *
135 * For example, in the initializer you may want to initialize embedded locks,
136 * NULL list pointers, set up initial states, magic numbers, etc. This way if
137 * the object is held in the allocator and re-used it won't be necessary to
138 * re-initialize it.
139 *
140 * The constructor may be used to lock a data structure, link it on to lists,
141 * bump reference counts or total counts of outstanding structures, etc.
142 *
143 */
144
145
146/* Function proto types */
147
148/*
149 * Create a new uma zone
150 *
151 * Arguments:
152 * name The text name of the zone for debugging and stats. This memory
153 * should not be freed until the zone has been deallocated.
154 * size The size of the object that is being created.
155 * ctor The constructor that is called when the object is allocated.
156 * dtor The destructor that is called when the object is freed.
157 * init An initializer that sets up the initial state of the memory.
158 * fini A discard function that undoes initialization done by init.
159 * ctor/dtor/init/fini may all be null, see notes above.
160 * align A bitmask that corresponds to the requested alignment
161 * eg 4 would be 0x3
162 * flags A set of parameters that control the behavior of the zone.
163 *
164 * Returns:
165 * A pointer to a structure which is intended to be opaque to users of
166 * the interface. The value may be null if the wait flag is not set.
167 */
168uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
169 uma_init uminit, uma_fini fini, int align,
170 u_int32_t flags);
171
172/*
173 * Create a secondary uma zone
174 *
175 * Arguments:
176 * name The text name of the zone for debugging and stats. This memory
177 * should not be freed until the zone has been deallocated.
178 * ctor The constructor that is called when the object is allocated.
179 * dtor The destructor that is called when the object is freed.
180 * zinit An initializer that sets up the initial state of the memory
181 * as the object passes from the Keg's slab to the Zone's cache.
182 * zfini A discard function that undoes initialization done by init
183 * as the object passes from the Zone's cache to the Keg's slab.
184 *
185 * ctor/dtor/zinit/zfini may all be null, see notes above.
186 * Note that the zinit and zfini specified here are NOT
187 * exactly the same as the init/fini specified to uma_zcreate()
188 * when creating a master zone. These zinit/zfini are called
189 * on the TRANSITION from keg to zone (and vice-versa). Once
190 * these are set, the primary zone may alter its init/fini
191 * (which are called when the object passes from VM to keg)
192 * using uma_zone_set_init/fini()) as well as its own
193 * zinit/zfini (unset by default for master zone) with
194 * uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
195 *
196 * master A reference to this zone's Master Zone (Primary Zone),
197 * which contains the backing Keg for the Secondary Zone
198 * being added.
199 *
200 * Returns:
201 * A pointer to a structure which is intended to be opaque to users of
202 * the interface. The value may be null if the wait flag is not set.
203 */
204uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
205 uma_init zinit, uma_fini zfini, uma_zone_t master);
206
207/*
208 * Add a second master to a secondary zone. This provides multiple data
209 * backends for objects with the same size. Both masters must have
210 * compatible allocation flags. Presently, UMA_ZONE_MALLOC type zones are
211 * the only supported.
212 *
213 * Returns:
214 * Error on failure, 0 on success.
215 */
216int uma_zsecond_add(uma_zone_t zone, uma_zone_t master);
217
218/*
219 * Definitions for uma_zcreate flags
220 *
221 * These flags share space with UMA_ZFLAGs in uma_int.h. Be careful not to
222 * overlap when adding new features. 0xf0000000 is in use by uma_int.h.
223 */
224#define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by
225 physical memory XXX Not yet */
226#define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */
227#define UMA_ZONE_STATIC 0x0004 /* Statically sized zone */
228#define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation
229 off of the real memory */
230#define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */
231#define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */
232#define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */
233#define UMA_ZONE_VM 0x0080 /*
234 * Used for internal vm datastructures
235 * only.
236 */
237#define UMA_ZONE_HASH 0x0100 /*
238 * Use a hash table instead of caching
239 * information in the vm_page.
240 */
241#define UMA_ZONE_SECONDARY 0x0200 /* Zone is a Secondary Zone */
242#define UMA_ZONE_REFCNT 0x0400 /* Allocate refcnts in slabs */
243#define UMA_ZONE_MAXBUCKET 0x0800 /* Use largest buckets */
244#define UMA_ZONE_CACHESPREAD 0x1000 /*
245 * Spread memory start locations across
246 * all possible cache lines. May
247 * require many virtually contiguous
248 * backend pages and can fail early.
249 */
250#define UMA_ZONE_VTOSLAB 0x2000 /* Zone uses vtoslab for lookup. */
251
252/*
253 * These flags are shared between the keg and zone. In zones wishing to add
254 * new kegs these flags must be compatible. Some are determined based on
255 * physical parameters of the request and may not be provided by the consumer.
256 */
257#define UMA_ZONE_INHERIT \
258 (UMA_ZONE_OFFPAGE | UMA_ZONE_MALLOC | UMA_ZONE_HASH | \
259 UMA_ZONE_REFCNT | UMA_ZONE_VTOSLAB)
260
261/* Definitions for align */
262#define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */
263#define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */
264#define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */
265#define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */
266#define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */
267#define UMA_ALIGN_CACHE (0 - 1) /* Cache line size align */
268
269/*
270 * Destroys an empty uma zone. If the zone is not empty uma complains loudly.
271 *
272 * Arguments:
273 * zone The zone we want to destroy.
274 *
275 */
276void uma_zdestroy(uma_zone_t zone);
277
278/*
279 * Allocates an item out of a zone
280 *
281 * Arguments:
282 * zone The zone we are allocating from
283 * arg This data is passed to the ctor function
284 * flags See sys/malloc.h for available flags.
285 *
286 * Returns:
287 * A non-null pointer to an initialized element from the zone is
288 * guaranteed if the wait flag is M_WAITOK. Otherwise a null pointer
289 * may be returned if the zone is empty or the ctor failed.
290 */
291
292void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
293
294/*
295 * Allocates an item out of a zone without supplying an argument
296 *
297 * This is just a wrapper for uma_zalloc_arg for convenience.
298 *
299 */
300static __inline void *uma_zalloc(uma_zone_t zone, int flags);
301
302static __inline void *
303uma_zalloc(uma_zone_t zone, int flags)
304{
305 return uma_zalloc_arg(zone, NULL, flags);
306}
307
308/*
309 * Frees an item back into the specified zone.
310 *
311 * Arguments:
312 * zone The zone the item was originally allocated out of.
313 * item The memory to be freed.
314 * arg Argument passed to the destructor
315 *
316 * Returns:
317 * Nothing.
318 */
319
320void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
321
322/*
323 * Frees an item back to a zone without supplying an argument
324 *
325 * This is just a wrapper for uma_zfree_arg for convenience.
326 *
327 */
328static __inline void uma_zfree(uma_zone_t zone, void *item);
329
330static __inline void
331uma_zfree(uma_zone_t zone, void *item)
332{
333 uma_zfree_arg(zone, item, NULL);
334}
335
336/*
337 * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
338 * If you think you need to use it for a normal zone you're probably incorrect.
339 */
340
341/*
342 * Backend page supplier routines
343 *
344 * Arguments:
345 * zone The zone that is requesting pages.
346 * size The number of bytes being requested.
347 * pflag Flags for these memory pages, see below.
348 * wait Indicates our willingness to block.
349 *
350 * Returns:
351 * A pointer to the allocated memory or NULL on failure.
352 */
353
354typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
355
356/*
357 * Backend page free routines
358 *
359 * Arguments:
360 * item A pointer to the previously allocated pages.
361 * size The original size of the allocation.
362 * pflag The flags for the slab. See UMA_SLAB_* below.
363 *
364 * Returns:
365 * None
366 */
367typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
368
369
370
371/*
372 * Sets up the uma allocator. (Called by vm_mem_init)
373 *
374 * Arguments:
375 * bootmem A pointer to memory used to bootstrap the system.
376 *
377 * Returns:
378 * Nothing
379 *
380 * Discussion:
381 * This memory is used for zones which allocate things before the
382 * backend page supplier can give us pages. It should be
383 * UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
384 *
385 */
386
387void uma_startup(void *bootmem, int boot_pages);
388
389/*
390 * Finishes starting up the allocator. This should
391 * be called when kva is ready for normal allocs.
392 *
393 * Arguments:
394 * None
395 *
396 * Returns:
397 * Nothing
398 *
399 * Discussion:
400 * uma_startup2 is called by kmeminit() to enable us of uma for malloc.
401 */
402
403void uma_startup2(void);
404
405/*
406 * Reclaims unused memory for all zones
407 *
408 * Arguments:
409 * None
410 * Returns:
411 * None
412 *
413 * This should only be called by the page out daemon.
414 */
415
416void uma_reclaim(void);
417
418/*
419 * Sets the alignment mask to be used for all zones requesting cache
420 * alignment. Should be called by MD boot code prior to starting VM/UMA.
421 *
422 * Arguments:
423 * align The alignment mask
424 *
425 * Returns:
426 * Nothing
427 */
428void uma_set_align(int align);
429
430/*
431 * Switches the backing object of a zone
432 *
433 * Arguments:
434 * zone The zone to update.
435 * obj The VM object to use for future allocations.
436 * size The size of the object to allocate.
437 *
438 * Returns:
439 * 0 if kva space can not be allocated
440 * 1 if successful
441 *
442 * Discussion:
443 * A NULL object can be used and uma will allocate one for you. Setting
444 * the size will limit the amount of memory allocated to this zone.
445 *
446 */
447struct vm_object;
448int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
449
450/*
451 * Sets a high limit on the number of items allowed in a zone
452 *
453 * Arguments:
454 * zone The zone to limit
455 * nitems The requested upper limit on the number of items allowed
456 *
457 * Returns:
458 * int The effective value of nitems after rounding up based on page size
459 */
460int uma_zone_set_max(uma_zone_t zone, int nitems);
461
462/*
463 * Obtains the effective limit on the number of items in a zone
464 *
465 * Arguments:
466 * zone The zone to obtain the effective limit from
467 *
468 * Return:
469 * 0 No limit
470 * int The effective limit of the zone
471 */
472int uma_zone_get_max(uma_zone_t zone);
473
474/*
475 * Obtains the approximate current number of items allocated from a zone
476 *
477 * Arguments:
478 * zone The zone to obtain the current allocation count from
479 *
480 * Return:
481 * int The approximate current number of items allocated from the zone
482 */
483int uma_zone_get_cur(uma_zone_t zone);
484
485/*
486 * The following two routines (uma_zone_set_init/fini)
487 * are used to set the backend init/fini pair which acts on an
488 * object as it becomes allocated and is placed in a slab within
489 * the specified zone's backing keg. These should probably not
490 * be changed once allocations have already begun, but only be set
491 * immediately upon zone creation.
492 */
493void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
494void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
495
496/*
497 * The following two routines (uma_zone_set_zinit/zfini) are
498 * used to set the zinit/zfini pair which acts on an object as
499 * it passes from the backing Keg's slab cache to the
500 * specified Zone's bucket cache. These should probably not
501 * be changed once allocations have already begun, but only be set
502 * immediately upon zone creation.
503 */
504void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
505void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
506
507/*
508 * Replaces the standard page_alloc or obj_alloc functions for this zone
509 *
510 * Arguments:
511 * zone The zone whose backend allocator is being changed.
512 * allocf A pointer to the allocation function
513 *
514 * Returns:
515 * Nothing
516 *
517 * Discussion:
518 * This could be used to implement pageable allocation, or perhaps
519 * even DMA allocators if used in conjunction with the OFFPAGE
520 * zone flag.
521 */
522
523void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
524
525/*
526 * Used for freeing memory provided by the allocf above
527 *
528 * Arguments:
529 * zone The zone that intends to use this free routine.
530 * freef The page freeing routine.
531 *
532 * Returns:
533 * Nothing
534 */
535
536void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
537
538/*
539 * These flags are setable in the allocf and visible in the freef.
540 */
541#define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
542#define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
543#define UMA_SLAB_KERNEL 0x04 /* Slab alloced from kernel_map */
544#define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
545#define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
546#define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */
547/* 0x40 and 0x80 are available */
548
549/*
550 * Used to pre-fill a zone with some number of items
551 *
552 * Arguments:
553 * zone The zone to fill
554 * itemcnt The number of items to reserve
555 *
556 * Returns:
557 * Nothing
558 *
559 * NOTE: This is blocking and should only be done at startup
560 */
561void uma_prealloc(uma_zone_t zone, int itemcnt);
562
563/*
564 * Used to lookup the reference counter allocated for an item
565 * from a UMA_ZONE_REFCNT zone. For UMA_ZONE_REFCNT zones,
566 * reference counters are allocated for items and stored in
567 * the underlying slab header.
568 *
569 * Arguments:
570 * zone The UMA_ZONE_REFCNT zone to which the item belongs.
571 * item The address of the item for which we want a refcnt.
572 *
573 * Returns:
574 * A pointer to a u_int32_t reference counter.
575 */
576u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
577
578/*
579 * Used to determine if a fixed-size zone is exhausted.
580 *
581 * Arguments:
582 * zone The zone to check
583 *
584 * Returns:
585 * Non-zero if zone is exhausted.
586 */
587int uma_zone_exhausted(uma_zone_t zone);
588int uma_zone_exhausted_nolock(uma_zone_t zone);
589
590/*
591 * Exported statistics structures to be used by user space monitoring tools.
592 * Statistics stream consists of a uma_stream_header, followed by a series of
593 * alternative uma_type_header and uma_type_stat structures.
594 */
595#define UMA_STREAM_VERSION 0x00000001
596struct uma_stream_header {
597 u_int32_t ush_version; /* Stream format version. */
598 u_int32_t ush_maxcpus; /* Value of MAXCPU for stream. */
599 u_int32_t ush_count; /* Number of records. */
600 u_int32_t _ush_pad; /* Pad/reserved field. */
601};
602
603#define UTH_MAX_NAME 32
604#define UTH_ZONE_SECONDARY 0x00000001
605struct uma_type_header {
606 /*
607 * Static per-zone data, some extracted from the supporting keg.
608 */
609 char uth_name[UTH_MAX_NAME];
610 u_int32_t uth_align; /* Keg: alignment. */
611 u_int32_t uth_size; /* Keg: requested size of item. */
612 u_int32_t uth_rsize; /* Keg: real size of item. */
613 u_int32_t uth_maxpages; /* Keg: maximum number of pages. */
614 u_int32_t uth_limit; /* Keg: max items to allocate. */
615
616 /*
617 * Current dynamic zone/keg-derived statistics.
618 */
619 u_int32_t uth_pages; /* Keg: pages allocated. */
620 u_int32_t uth_keg_free; /* Keg: items free. */
621 u_int32_t uth_zone_free; /* Zone: items free. */
622 u_int32_t uth_bucketsize; /* Zone: desired bucket size. */
623 u_int32_t uth_zone_flags; /* Zone: flags. */
624 u_int64_t uth_allocs; /* Zone: number of allocations. */
625 u_int64_t uth_frees; /* Zone: number of frees. */
626 u_int64_t uth_fails; /* Zone: number of alloc failures. */
627 u_int64_t uth_sleeps; /* Zone: number of alloc sleeps. */
628 u_int64_t _uth_reserved1[2]; /* Reserved. */
629};
630
631struct uma_percpu_stat {
632 u_int64_t ups_allocs; /* Cache: number of allocations. */
633 u_int64_t ups_frees; /* Cache: number of frees. */
634 u_int64_t ups_cache_free; /* Cache: free items in cache. */
635 u_int64_t _ups_reserved[5]; /* Reserved. */
636};
637
638#endif
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: head/sys/vm/uma.h 213911 2010-10-16 04:41:45Z lstewart $
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 visible parameters */
43#define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */
44
45/* Types and type defs */
46
47struct uma_zone;
48/* Opaque type used as a handle to the zone */
49typedef struct uma_zone * uma_zone_t;
50
51void zone_drain(uma_zone_t);
52
53/*
54 * Item constructor
55 *
56 * Arguments:
57 * item A pointer to the memory which has been allocated.
58 * arg The arg field passed to uma_zalloc_arg
59 * size The size of the allocated item
60 * flags See zalloc flags
61 *
62 * Returns:
63 * 0 on success
64 * errno on failure
65 *
66 * Discussion:
67 * The constructor is called just before the memory is returned
68 * to the user. It may block if necessary.
69 */
70typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
71
72/*
73 * Item destructor
74 *
75 * Arguments:
76 * item A pointer to the memory which has been allocated.
77 * size The size of the item being destructed.
78 * arg Argument passed through uma_zfree_arg
79 *
80 * Returns:
81 * Nothing
82 *
83 * Discussion:
84 * The destructor may perform operations that differ from those performed
85 * by the initializer, but it must leave the object in the same state.
86 * This IS type stable storage. This is called after EVERY zfree call.
87 */
88typedef void (*uma_dtor)(void *mem, int size, void *arg);
89
90/*
91 * Item initializer
92 *
93 * Arguments:
94 * item A pointer to the memory which has been allocated.
95 * size The size of the item being initialized.
96 * flags See zalloc flags
97 *
98 * Returns:
99 * 0 on success
100 * errno on failure
101 *
102 * Discussion:
103 * The initializer is called when the memory is cached in the uma zone.
104 * The initializer and the destructor should leave the object in the same
105 * state.
106 */
107typedef int (*uma_init)(void *mem, int size, int flags);
108
109/*
110 * Item discard function
111 *
112 * Arguments:
113 * item A pointer to memory which has been 'freed' but has not left the
114 * zone's cache.
115 * size The size of the item being discarded.
116 *
117 * Returns:
118 * Nothing
119 *
120 * Discussion:
121 * This routine is called when memory leaves a zone and is returned to the
122 * system for other uses. It is the counter-part to the init function.
123 */
124typedef void (*uma_fini)(void *mem, int size);
125
126/*
127 * What's the difference between initializing and constructing?
128 *
129 * The item is initialized when it is cached, and this is the state that the
130 * object should be in when returned to the allocator. The purpose of this is
131 * to remove some code which would otherwise be called on each allocation by
132 * utilizing a known, stable state. This differs from the constructor which
133 * will be called on EVERY allocation.
134 *
135 * For example, in the initializer you may want to initialize embedded locks,
136 * NULL list pointers, set up initial states, magic numbers, etc. This way if
137 * the object is held in the allocator and re-used it won't be necessary to
138 * re-initialize it.
139 *
140 * The constructor may be used to lock a data structure, link it on to lists,
141 * bump reference counts or total counts of outstanding structures, etc.
142 *
143 */
144
145
146/* Function proto types */
147
148/*
149 * Create a new uma zone
150 *
151 * Arguments:
152 * name The text name of the zone for debugging and stats. This memory
153 * should not be freed until the zone has been deallocated.
154 * size The size of the object that is being created.
155 * ctor The constructor that is called when the object is allocated.
156 * dtor The destructor that is called when the object is freed.
157 * init An initializer that sets up the initial state of the memory.
158 * fini A discard function that undoes initialization done by init.
159 * ctor/dtor/init/fini may all be null, see notes above.
160 * align A bitmask that corresponds to the requested alignment
161 * eg 4 would be 0x3
162 * flags A set of parameters that control the behavior of the zone.
163 *
164 * Returns:
165 * A pointer to a structure which is intended to be opaque to users of
166 * the interface. The value may be null if the wait flag is not set.
167 */
168uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
169 uma_init uminit, uma_fini fini, int align,
170 u_int32_t flags);
171
172/*
173 * Create a secondary uma zone
174 *
175 * Arguments:
176 * name The text name of the zone for debugging and stats. This memory
177 * should not be freed until the zone has been deallocated.
178 * ctor The constructor that is called when the object is allocated.
179 * dtor The destructor that is called when the object is freed.
180 * zinit An initializer that sets up the initial state of the memory
181 * as the object passes from the Keg's slab to the Zone's cache.
182 * zfini A discard function that undoes initialization done by init
183 * as the object passes from the Zone's cache to the Keg's slab.
184 *
185 * ctor/dtor/zinit/zfini may all be null, see notes above.
186 * Note that the zinit and zfini specified here are NOT
187 * exactly the same as the init/fini specified to uma_zcreate()
188 * when creating a master zone. These zinit/zfini are called
189 * on the TRANSITION from keg to zone (and vice-versa). Once
190 * these are set, the primary zone may alter its init/fini
191 * (which are called when the object passes from VM to keg)
192 * using uma_zone_set_init/fini()) as well as its own
193 * zinit/zfini (unset by default for master zone) with
194 * uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
195 *
196 * master A reference to this zone's Master Zone (Primary Zone),
197 * which contains the backing Keg for the Secondary Zone
198 * being added.
199 *
200 * Returns:
201 * A pointer to a structure which is intended to be opaque to users of
202 * the interface. The value may be null if the wait flag is not set.
203 */
204uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
205 uma_init zinit, uma_fini zfini, uma_zone_t master);
206
207/*
208 * Add a second master to a secondary zone. This provides multiple data
209 * backends for objects with the same size. Both masters must have
210 * compatible allocation flags. Presently, UMA_ZONE_MALLOC type zones are
211 * the only supported.
212 *
213 * Returns:
214 * Error on failure, 0 on success.
215 */
216int uma_zsecond_add(uma_zone_t zone, uma_zone_t master);
217
218/*
219 * Definitions for uma_zcreate flags
220 *
221 * These flags share space with UMA_ZFLAGs in uma_int.h. Be careful not to
222 * overlap when adding new features. 0xf0000000 is in use by uma_int.h.
223 */
224#define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by
225 physical memory XXX Not yet */
226#define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */
227#define UMA_ZONE_STATIC 0x0004 /* Statically sized zone */
228#define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation
229 off of the real memory */
230#define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */
231#define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */
232#define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */
233#define UMA_ZONE_VM 0x0080 /*
234 * Used for internal vm datastructures
235 * only.
236 */
237#define UMA_ZONE_HASH 0x0100 /*
238 * Use a hash table instead of caching
239 * information in the vm_page.
240 */
241#define UMA_ZONE_SECONDARY 0x0200 /* Zone is a Secondary Zone */
242#define UMA_ZONE_REFCNT 0x0400 /* Allocate refcnts in slabs */
243#define UMA_ZONE_MAXBUCKET 0x0800 /* Use largest buckets */
244#define UMA_ZONE_CACHESPREAD 0x1000 /*
245 * Spread memory start locations across
246 * all possible cache lines. May
247 * require many virtually contiguous
248 * backend pages and can fail early.
249 */
250#define UMA_ZONE_VTOSLAB 0x2000 /* Zone uses vtoslab for lookup. */
251
252/*
253 * These flags are shared between the keg and zone. In zones wishing to add
254 * new kegs these flags must be compatible. Some are determined based on
255 * physical parameters of the request and may not be provided by the consumer.
256 */
257#define UMA_ZONE_INHERIT \
258 (UMA_ZONE_OFFPAGE | UMA_ZONE_MALLOC | UMA_ZONE_HASH | \
259 UMA_ZONE_REFCNT | UMA_ZONE_VTOSLAB)
260
261/* Definitions for align */
262#define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */
263#define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */
264#define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */
265#define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */
266#define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */
267#define UMA_ALIGN_CACHE (0 - 1) /* Cache line size align */
268
269/*
270 * Destroys an empty uma zone. If the zone is not empty uma complains loudly.
271 *
272 * Arguments:
273 * zone The zone we want to destroy.
274 *
275 */
276void uma_zdestroy(uma_zone_t zone);
277
278/*
279 * Allocates an item out of a zone
280 *
281 * Arguments:
282 * zone The zone we are allocating from
283 * arg This data is passed to the ctor function
284 * flags See sys/malloc.h for available flags.
285 *
286 * Returns:
287 * A non-null pointer to an initialized element from the zone is
288 * guaranteed if the wait flag is M_WAITOK. Otherwise a null pointer
289 * may be returned if the zone is empty or the ctor failed.
290 */
291
292void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
293
294/*
295 * Allocates an item out of a zone without supplying an argument
296 *
297 * This is just a wrapper for uma_zalloc_arg for convenience.
298 *
299 */
300static __inline void *uma_zalloc(uma_zone_t zone, int flags);
301
302static __inline void *
303uma_zalloc(uma_zone_t zone, int flags)
304{
305 return uma_zalloc_arg(zone, NULL, flags);
306}
307
308/*
309 * Frees an item back into the specified zone.
310 *
311 * Arguments:
312 * zone The zone the item was originally allocated out of.
313 * item The memory to be freed.
314 * arg Argument passed to the destructor
315 *
316 * Returns:
317 * Nothing.
318 */
319
320void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
321
322/*
323 * Frees an item back to a zone without supplying an argument
324 *
325 * This is just a wrapper for uma_zfree_arg for convenience.
326 *
327 */
328static __inline void uma_zfree(uma_zone_t zone, void *item);
329
330static __inline void
331uma_zfree(uma_zone_t zone, void *item)
332{
333 uma_zfree_arg(zone, item, NULL);
334}
335
336/*
337 * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
338 * If you think you need to use it for a normal zone you're probably incorrect.
339 */
340
341/*
342 * Backend page supplier routines
343 *
344 * Arguments:
345 * zone The zone that is requesting pages.
346 * size The number of bytes being requested.
347 * pflag Flags for these memory pages, see below.
348 * wait Indicates our willingness to block.
349 *
350 * Returns:
351 * A pointer to the allocated memory or NULL on failure.
352 */
353
354typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
355
356/*
357 * Backend page free routines
358 *
359 * Arguments:
360 * item A pointer to the previously allocated pages.
361 * size The original size of the allocation.
362 * pflag The flags for the slab. See UMA_SLAB_* below.
363 *
364 * Returns:
365 * None
366 */
367typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
368
369
370
371/*
372 * Sets up the uma allocator. (Called by vm_mem_init)
373 *
374 * Arguments:
375 * bootmem A pointer to memory used to bootstrap the system.
376 *
377 * Returns:
378 * Nothing
379 *
380 * Discussion:
381 * This memory is used for zones which allocate things before the
382 * backend page supplier can give us pages. It should be
383 * UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
384 *
385 */
386
387void uma_startup(void *bootmem, int boot_pages);
388
389/*
390 * Finishes starting up the allocator. This should
391 * be called when kva is ready for normal allocs.
392 *
393 * Arguments:
394 * None
395 *
396 * Returns:
397 * Nothing
398 *
399 * Discussion:
400 * uma_startup2 is called by kmeminit() to enable us of uma for malloc.
401 */
402
403void uma_startup2(void);
404
405/*
406 * Reclaims unused memory for all zones
407 *
408 * Arguments:
409 * None
410 * Returns:
411 * None
412 *
413 * This should only be called by the page out daemon.
414 */
415
416void uma_reclaim(void);
417
418/*
419 * Sets the alignment mask to be used for all zones requesting cache
420 * alignment. Should be called by MD boot code prior to starting VM/UMA.
421 *
422 * Arguments:
423 * align The alignment mask
424 *
425 * Returns:
426 * Nothing
427 */
428void uma_set_align(int align);
429
430/*
431 * Switches the backing object of a zone
432 *
433 * Arguments:
434 * zone The zone to update.
435 * obj The VM object to use for future allocations.
436 * size The size of the object to allocate.
437 *
438 * Returns:
439 * 0 if kva space can not be allocated
440 * 1 if successful
441 *
442 * Discussion:
443 * A NULL object can be used and uma will allocate one for you. Setting
444 * the size will limit the amount of memory allocated to this zone.
445 *
446 */
447struct vm_object;
448int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
449
450/*
451 * Sets a high limit on the number of items allowed in a zone
452 *
453 * Arguments:
454 * zone The zone to limit
455 * nitems The requested upper limit on the number of items allowed
456 *
457 * Returns:
458 * int The effective value of nitems after rounding up based on page size
459 */
460int uma_zone_set_max(uma_zone_t zone, int nitems);
461
462/*
463 * Obtains the effective limit on the number of items in a zone
464 *
465 * Arguments:
466 * zone The zone to obtain the effective limit from
467 *
468 * Return:
469 * 0 No limit
470 * int The effective limit of the zone
471 */
472int uma_zone_get_max(uma_zone_t zone);
473
474/*
475 * Obtains the approximate current number of items allocated from a zone
476 *
477 * Arguments:
478 * zone The zone to obtain the current allocation count from
479 *
480 * Return:
481 * int The approximate current number of items allocated from the zone
482 */
483int uma_zone_get_cur(uma_zone_t zone);
484
485/*
486 * The following two routines (uma_zone_set_init/fini)
487 * are used to set the backend init/fini pair which acts on an
488 * object as it becomes allocated and is placed in a slab within
489 * the specified zone's backing keg. These should probably not
490 * be changed once allocations have already begun, but only be set
491 * immediately upon zone creation.
492 */
493void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
494void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
495
496/*
497 * The following two routines (uma_zone_set_zinit/zfini) are
498 * used to set the zinit/zfini pair which acts on an object as
499 * it passes from the backing Keg's slab cache to the
500 * specified Zone's bucket cache. These should probably not
501 * be changed once allocations have already begun, but only be set
502 * immediately upon zone creation.
503 */
504void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
505void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
506
507/*
508 * Replaces the standard page_alloc or obj_alloc functions for this zone
509 *
510 * Arguments:
511 * zone The zone whose backend allocator is being changed.
512 * allocf A pointer to the allocation function
513 *
514 * Returns:
515 * Nothing
516 *
517 * Discussion:
518 * This could be used to implement pageable allocation, or perhaps
519 * even DMA allocators if used in conjunction with the OFFPAGE
520 * zone flag.
521 */
522
523void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
524
525/*
526 * Used for freeing memory provided by the allocf above
527 *
528 * Arguments:
529 * zone The zone that intends to use this free routine.
530 * freef The page freeing routine.
531 *
532 * Returns:
533 * Nothing
534 */
535
536void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
537
538/*
539 * These flags are setable in the allocf and visible in the freef.
540 */
541#define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
542#define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
543#define UMA_SLAB_KERNEL 0x04 /* Slab alloced from kernel_map */
544#define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
545#define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
546#define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */
547/* 0x40 and 0x80 are available */
548
549/*
550 * Used to pre-fill a zone with some number of items
551 *
552 * Arguments:
553 * zone The zone to fill
554 * itemcnt The number of items to reserve
555 *
556 * Returns:
557 * Nothing
558 *
559 * NOTE: This is blocking and should only be done at startup
560 */
561void uma_prealloc(uma_zone_t zone, int itemcnt);
562
563/*
564 * Used to lookup the reference counter allocated for an item
565 * from a UMA_ZONE_REFCNT zone. For UMA_ZONE_REFCNT zones,
566 * reference counters are allocated for items and stored in
567 * the underlying slab header.
568 *
569 * Arguments:
570 * zone The UMA_ZONE_REFCNT zone to which the item belongs.
571 * item The address of the item for which we want a refcnt.
572 *
573 * Returns:
574 * A pointer to a u_int32_t reference counter.
575 */
576u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
577
578/*
579 * Used to determine if a fixed-size zone is exhausted.
580 *
581 * Arguments:
582 * zone The zone to check
583 *
584 * Returns:
585 * Non-zero if zone is exhausted.
586 */
587int uma_zone_exhausted(uma_zone_t zone);
588int uma_zone_exhausted_nolock(uma_zone_t zone);
589
590/*
591 * Exported statistics structures to be used by user space monitoring tools.
592 * Statistics stream consists of a uma_stream_header, followed by a series of
593 * alternative uma_type_header and uma_type_stat structures.
594 */
595#define UMA_STREAM_VERSION 0x00000001
596struct uma_stream_header {
597 u_int32_t ush_version; /* Stream format version. */
598 u_int32_t ush_maxcpus; /* Value of MAXCPU for stream. */
599 u_int32_t ush_count; /* Number of records. */
600 u_int32_t _ush_pad; /* Pad/reserved field. */
601};
602
603#define UTH_MAX_NAME 32
604#define UTH_ZONE_SECONDARY 0x00000001
605struct uma_type_header {
606 /*
607 * Static per-zone data, some extracted from the supporting keg.
608 */
609 char uth_name[UTH_MAX_NAME];
610 u_int32_t uth_align; /* Keg: alignment. */
611 u_int32_t uth_size; /* Keg: requested size of item. */
612 u_int32_t uth_rsize; /* Keg: real size of item. */
613 u_int32_t uth_maxpages; /* Keg: maximum number of pages. */
614 u_int32_t uth_limit; /* Keg: max items to allocate. */
615
616 /*
617 * Current dynamic zone/keg-derived statistics.
618 */
619 u_int32_t uth_pages; /* Keg: pages allocated. */
620 u_int32_t uth_keg_free; /* Keg: items free. */
621 u_int32_t uth_zone_free; /* Zone: items free. */
622 u_int32_t uth_bucketsize; /* Zone: desired bucket size. */
623 u_int32_t uth_zone_flags; /* Zone: flags. */
624 u_int64_t uth_allocs; /* Zone: number of allocations. */
625 u_int64_t uth_frees; /* Zone: number of frees. */
626 u_int64_t uth_fails; /* Zone: number of alloc failures. */
627 u_int64_t uth_sleeps; /* Zone: number of alloc sleeps. */
628 u_int64_t _uth_reserved1[2]; /* Reserved. */
629};
630
631struct uma_percpu_stat {
632 u_int64_t ups_allocs; /* Cache: number of allocations. */
633 u_int64_t ups_frees; /* Cache: number of frees. */
634 u_int64_t ups_cache_free; /* Cache: free items in cache. */
635 u_int64_t _ups_reserved[5]; /* Reserved. */
636};
637
638#endif