2 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
3 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice unmodified, this list of conditions, and the following
12 * 2. Redistributions in binary form must reproduce the above copyright
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14 * documentation and/or other materials provided with the distribution.
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25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 * uma.h - External definitions for the Universal Memory Allocator
39 #include <sys/param.h> /* For NULL */
40 #include <sys/malloc.h> /* For M_* */
42 /* User visible parameters */
43 #define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */
45 /* Types and type defs */
48 /* Opaque type used as a handle to the zone */
49 typedef struct uma_zone * uma_zone_t;
51 void zone_drain(uma_zone_t);
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
67 * The constructor is called just before the memory is returned
68 * to the user. It may block if necessary.
70 typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
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
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.
88 typedef void (*uma_dtor)(void *mem, int size, void *arg);
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
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
107 typedef int (*uma_init)(void *mem, int size, int flags);
110 * Item discard function
113 * item A pointer to memory which has been 'freed' but has not left the
115 * size The size of the item being discarded.
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.
124 typedef void (*uma_fini)(void *mem, int size);
127 * What's the difference between initializing and constructing?
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.
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
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.
146 /* Function proto types */
149 * Create a new uma zone
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
162 * flags A set of parameters that control the behavior of the zone.
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.
168 uma_zone_t uma_zcreate(const char *name, size_t size, uma_ctor ctor,
169 uma_dtor dtor, uma_init uminit, uma_fini fini,
170 int align, uint32_t flags);
173 * Create a secondary uma zone
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.
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).
196 * master A reference to this zone's Master Zone (Primary Zone),
197 * which contains the backing Keg for the Secondary Zone
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.
204 uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
205 uma_init zinit, uma_fini zfini, uma_zone_t master);
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.
214 * Error on failure, 0 on success.
216 int uma_zsecond_add(uma_zone_t zone, uma_zone_t master);
219 * Definitions for uma_zcreate flags
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.
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
237 #define UMA_ZONE_HASH 0x0100 /*
238 * Use a hash table instead of caching
239 * information in the vm_page.
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.
250 #define UMA_ZONE_VTOSLAB 0x2000 /* Zone uses vtoslab for lookup. */
251 #define UMA_ZONE_NODUMP 0x4000 /*
252 * Zone's pages will not be included in
255 #define UMA_ZONE_PCPU 0x8000 /*
256 * Allocates mp_ncpus slabs sized to
257 * sizeof(struct pcpu).
261 * These flags are shared between the keg and zone. In zones wishing to add
262 * new kegs these flags must be compatible. Some are determined based on
263 * physical parameters of the request and may not be provided by the consumer.
265 #define UMA_ZONE_INHERIT \
266 (UMA_ZONE_OFFPAGE | UMA_ZONE_MALLOC | UMA_ZONE_NOFREE | \
267 UMA_ZONE_HASH | UMA_ZONE_REFCNT | UMA_ZONE_VTOSLAB | UMA_ZONE_PCPU)
269 /* Definitions for align */
270 #define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */
271 #define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */
272 #define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */
273 #define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */
274 #define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */
275 #define UMA_ALIGN_CACHE (0 - 1) /* Cache line size align */
278 * Destroys an empty uma zone. If the zone is not empty uma complains loudly.
281 * zone The zone we want to destroy.
284 void uma_zdestroy(uma_zone_t zone);
287 * Allocates an item out of a zone
290 * zone The zone we are allocating from
291 * arg This data is passed to the ctor function
292 * flags See sys/malloc.h for available flags.
295 * A non-null pointer to an initialized element from the zone is
296 * guaranteed if the wait flag is M_WAITOK. Otherwise a null pointer
297 * may be returned if the zone is empty or the ctor failed.
300 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
303 * Allocates an item out of a zone without supplying an argument
305 * This is just a wrapper for uma_zalloc_arg for convenience.
308 static __inline void *uma_zalloc(uma_zone_t zone, int flags);
310 static __inline void *
311 uma_zalloc(uma_zone_t zone, int flags)
313 return uma_zalloc_arg(zone, NULL, flags);
317 * Frees an item back into the specified zone.
320 * zone The zone the item was originally allocated out of.
321 * item The memory to be freed.
322 * arg Argument passed to the destructor
328 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
331 * Frees an item back to a zone without supplying an argument
333 * This is just a wrapper for uma_zfree_arg for convenience.
336 static __inline void uma_zfree(uma_zone_t zone, void *item);
339 uma_zfree(uma_zone_t zone, void *item)
341 uma_zfree_arg(zone, item, NULL);
345 * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
346 * If you think you need to use it for a normal zone you're probably incorrect.
350 * Backend page supplier routines
353 * zone The zone that is requesting pages.
354 * size The number of bytes being requested.
355 * pflag Flags for these memory pages, see below.
356 * wait Indicates our willingness to block.
359 * A pointer to the allocated memory or NULL on failure.
362 typedef void *(*uma_alloc)(uma_zone_t zone, int size, uint8_t *pflag, int wait);
365 * Backend page free routines
368 * item A pointer to the previously allocated pages.
369 * size The original size of the allocation.
370 * pflag The flags for the slab. See UMA_SLAB_* below.
375 typedef void (*uma_free)(void *item, int size, uint8_t pflag);
380 * Sets up the uma allocator. (Called by vm_mem_init)
383 * bootmem A pointer to memory used to bootstrap the system.
389 * This memory is used for zones which allocate things before the
390 * backend page supplier can give us pages. It should be
391 * UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
395 void uma_startup(void *bootmem, int boot_pages);
398 * Finishes starting up the allocator. This should
399 * be called when kva is ready for normal allocs.
408 * uma_startup2 is called by kmeminit() to enable us of uma for malloc.
411 void uma_startup2(void);
414 * Reclaims unused memory for all zones
421 * This should only be called by the page out daemon.
424 void uma_reclaim(void);
427 * Sets the alignment mask to be used for all zones requesting cache
428 * alignment. Should be called by MD boot code prior to starting VM/UMA.
431 * align The alignment mask
436 void uma_set_align(int align);
439 * Reserves the maximum KVA space required by the zone and configures the zone
440 * to use a VM_ALLOC_NOOBJ-based backend allocator.
443 * zone The zone to update.
444 * nitems The upper limit on the number of items that can be allocated.
447 * 0 if KVA space can not be allocated
451 * When the machine supports a direct map and the zone's items are smaller
452 * than a page, the zone will use the direct map instead of allocating KVA
455 int uma_zone_reserve_kva(uma_zone_t zone, int nitems);
458 * Sets a high limit on the number of items allowed in a zone
461 * zone The zone to limit
462 * nitems The requested upper limit on the number of items allowed
465 * int The effective value of nitems after rounding up based on page size
467 int uma_zone_set_max(uma_zone_t zone, int nitems);
470 * Obtains the effective limit on the number of items in a zone
473 * zone The zone to obtain the effective limit from
477 * int The effective limit of the zone
479 int uma_zone_get_max(uma_zone_t zone);
482 * Sets a warning to be printed when limit is reached
485 * zone The zone we will warn about
486 * warning Warning content
491 void uma_zone_set_warning(uma_zone_t zone, const char *warning);
494 * Obtains the approximate current number of items allocated from a zone
497 * zone The zone to obtain the current allocation count from
500 * int The approximate current number of items allocated from the zone
502 int uma_zone_get_cur(uma_zone_t zone);
505 * The following two routines (uma_zone_set_init/fini)
506 * are used to set the backend init/fini pair which acts on an
507 * object as it becomes allocated and is placed in a slab within
508 * the specified zone's backing keg. These should probably not
509 * be changed once allocations have already begun, but only be set
510 * immediately upon zone creation.
512 void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
513 void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
516 * The following two routines (uma_zone_set_zinit/zfini) are
517 * used to set the zinit/zfini pair which acts on an object as
518 * it passes from the backing Keg's slab cache to the
519 * specified Zone's bucket cache. These should probably not
520 * be changed once allocations have already begun, but only be set
521 * immediately upon zone creation.
523 void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
524 void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
527 * Replaces the standard backend allocator for this zone.
530 * zone The zone whose backend allocator is being changed.
531 * allocf A pointer to the allocation function
537 * This could be used to implement pageable allocation, or perhaps
538 * even DMA allocators if used in conjunction with the OFFPAGE
542 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
545 * Used for freeing memory provided by the allocf above
548 * zone The zone that intends to use this free routine.
549 * freef The page freeing routine.
555 void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
558 * These flags are setable in the allocf and visible in the freef.
560 #define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */
561 #define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */
562 #define UMA_SLAB_KERNEL 0x04 /* Slab alloced from kernel_map */
563 #define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */
564 #define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */
565 #define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */
566 /* 0x40 and 0x80 are available */
569 * Used to pre-fill a zone with some number of items
572 * zone The zone to fill
573 * itemcnt The number of items to reserve
578 * NOTE: This is blocking and should only be done at startup
580 void uma_prealloc(uma_zone_t zone, int itemcnt);
583 * Used to lookup the reference counter allocated for an item
584 * from a UMA_ZONE_REFCNT zone. For UMA_ZONE_REFCNT zones,
585 * reference counters are allocated for items and stored in
586 * the underlying slab header.
589 * zone The UMA_ZONE_REFCNT zone to which the item belongs.
590 * item The address of the item for which we want a refcnt.
593 * A pointer to a uint32_t reference counter.
595 uint32_t *uma_find_refcnt(uma_zone_t zone, void *item);
598 * Used to determine if a fixed-size zone is exhausted.
601 * zone The zone to check
604 * Non-zero if zone is exhausted.
606 int uma_zone_exhausted(uma_zone_t zone);
607 int uma_zone_exhausted_nolock(uma_zone_t zone);
610 * Exported statistics structures to be used by user space monitoring tools.
611 * Statistics stream consists of a uma_stream_header, followed by a series of
612 * alternative uma_type_header and uma_type_stat structures.
614 #define UMA_STREAM_VERSION 0x00000001
615 struct uma_stream_header {
616 uint32_t ush_version; /* Stream format version. */
617 uint32_t ush_maxcpus; /* Value of MAXCPU for stream. */
618 uint32_t ush_count; /* Number of records. */
619 uint32_t _ush_pad; /* Pad/reserved field. */
622 #define UTH_MAX_NAME 32
623 #define UTH_ZONE_SECONDARY 0x00000001
624 struct uma_type_header {
626 * Static per-zone data, some extracted from the supporting keg.
628 char uth_name[UTH_MAX_NAME];
629 uint32_t uth_align; /* Keg: alignment. */
630 uint32_t uth_size; /* Keg: requested size of item. */
631 uint32_t uth_rsize; /* Keg: real size of item. */
632 uint32_t uth_maxpages; /* Keg: maximum number of pages. */
633 uint32_t uth_limit; /* Keg: max items to allocate. */
636 * Current dynamic zone/keg-derived statistics.
638 uint32_t uth_pages; /* Keg: pages allocated. */
639 uint32_t uth_keg_free; /* Keg: items free. */
640 uint32_t uth_zone_free; /* Zone: items free. */
641 uint32_t uth_bucketsize; /* Zone: desired bucket size. */
642 uint32_t uth_zone_flags; /* Zone: flags. */
643 uint64_t uth_allocs; /* Zone: number of allocations. */
644 uint64_t uth_frees; /* Zone: number of frees. */
645 uint64_t uth_fails; /* Zone: number of alloc failures. */
646 uint64_t uth_sleeps; /* Zone: number of alloc sleeps. */
647 uint64_t _uth_reserved1[2]; /* Reserved. */
650 struct uma_percpu_stat {
651 uint64_t ups_allocs; /* Cache: number of allocations. */
652 uint64_t ups_frees; /* Cache: number of frees. */
653 uint64_t ups_cache_free; /* Cache: free items in cache. */
654 uint64_t _ups_reserved[5]; /* Reserved. */