xref: /freebsd/sys/vm/uma.h (revision d65cd7a57bf0600b722afc770838a5d0c1c3a8e1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
5  * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  *
31  */
32 
33 /*
34  * uma.h - External definitions for the Universal Memory Allocator
35  *
36 */
37 
38 #ifndef _VM_UMA_H_
39 #define _VM_UMA_H_
40 
41 #include <sys/param.h>		/* For NULL */
42 #include <sys/malloc.h>		/* For M_* */
43 #include <sys/_smr.h>
44 
45 /* User visible parameters */
46 #define	UMA_SMALLEST_UNIT	8 /* Smallest item allocated */
47 
48 /* Types and type defs */
49 
50 struct uma_zone;
51 /* Opaque type used as a handle to the zone */
52 typedef struct uma_zone * uma_zone_t;
53 
54 /*
55  * Item constructor
56  *
57  * Arguments:
58  *	item  A pointer to the memory which has been allocated.
59  *	arg   The arg field passed to uma_zalloc_arg
60  *	size  The size of the allocated item
61  *	flags See zalloc flags
62  *
63  * Returns:
64  *	0      on success
65  *      errno  on failure
66  *
67  * Discussion:
68  *	The constructor is called just before the memory is returned
69  *	to the user. It may block if necessary.
70  */
71 typedef int (*uma_ctor)(void *mem, int size, void *arg, int flags);
72 
73 /*
74  * Item destructor
75  *
76  * Arguments:
77  *	item  A pointer to the memory which has been allocated.
78  *	size  The size of the item being destructed.
79  *	arg   Argument passed through uma_zfree_arg
80  *
81  * Returns:
82  *	Nothing
83  *
84  * Discussion:
85  *	The destructor may perform operations that differ from those performed
86  *	by the initializer, but it must leave the object in the same state.
87  *	This IS type stable storage.  This is called after EVERY zfree call.
88  */
89 typedef void (*uma_dtor)(void *mem, int size, void *arg);
90 
91 /*
92  * Item initializer
93  *
94  * Arguments:
95  *	item  A pointer to the memory which has been allocated.
96  *	size  The size of the item being initialized.
97  *	flags See zalloc flags
98  *
99  * Returns:
100  *	0      on success
101  *      errno  on failure
102  *
103  * Discussion:
104  *	The initializer is called when the memory is cached in the uma zone.
105  *	The initializer and the destructor should leave the object in the same
106  *	state.
107  */
108 typedef int (*uma_init)(void *mem, int size, int flags);
109 
110 /*
111  * Item discard function
112  *
113  * Arguments:
114  *	item  A pointer to memory which has been 'freed' but has not left the
115  *	      zone's cache.
116  *	size  The size of the item being discarded.
117  *
118  * Returns:
119  *	Nothing
120  *
121  * Discussion:
122  *	This routine is called when memory leaves a zone and is returned to the
123  *	system for other uses.  It is the counter-part to the init function.
124  */
125 typedef void (*uma_fini)(void *mem, int size);
126 
127 /*
128  * Import new memory into a cache zone.
129  */
130 typedef int (*uma_import)(void *arg, void **store, int count, int domain,
131     int flags);
132 
133 /*
134  * Free memory from a cache zone.
135  */
136 typedef void (*uma_release)(void *arg, void **store, int count);
137 
138 /*
139  * What's the difference between initializing and constructing?
140  *
141  * The item is initialized when it is cached, and this is the state that the
142  * object should be in when returned to the allocator. The purpose of this is
143  * to remove some code which would otherwise be called on each allocation by
144  * utilizing a known, stable state.  This differs from the constructor which
145  * will be called on EVERY allocation.
146  *
147  * For example, in the initializer you may want to initialize embedded locks,
148  * NULL list pointers, set up initial states, magic numbers, etc.  This way if
149  * the object is held in the allocator and re-used it won't be necessary to
150  * re-initialize it.
151  *
152  * The constructor may be used to lock a data structure, link it on to lists,
153  * bump reference counts or total counts of outstanding structures, etc.
154  *
155  */
156 
157 
158 /* Function proto types */
159 
160 /*
161  * Create a new uma zone
162  *
163  * Arguments:
164  *	name  The text name of the zone for debugging and stats. This memory
165  *		should not be freed until the zone has been deallocated.
166  *	size  The size of the object that is being created.
167  *	ctor  The constructor that is called when the object is allocated.
168  *	dtor  The destructor that is called when the object is freed.
169  *	init  An initializer that sets up the initial state of the memory.
170  *	fini  A discard function that undoes initialization done by init.
171  *		ctor/dtor/init/fini may all be null, see notes above.
172  *	align A bitmask that corresponds to the requested alignment
173  *		eg 4 would be 0x3
174  *	flags A set of parameters that control the behavior of the zone.
175  *
176  * Returns:
177  *	A pointer to a structure which is intended to be opaque to users of
178  *	the interface.  The value may be null if the wait flag is not set.
179  */
180 uma_zone_t uma_zcreate(const char *name, size_t size, uma_ctor ctor,
181 		    uma_dtor dtor, uma_init uminit, uma_fini fini,
182 		    int align, uint32_t flags);
183 
184 /*
185  * Create a secondary uma zone
186  *
187  * Arguments:
188  *	name  The text name of the zone for debugging and stats. This memory
189  *		should not be freed until the zone has been deallocated.
190  *	ctor  The constructor that is called when the object is allocated.
191  *	dtor  The destructor that is called when the object is freed.
192  *	zinit  An initializer that sets up the initial state of the memory
193  *		as the object passes from the Keg's slab to the Zone's cache.
194  *	zfini  A discard function that undoes initialization done by init
195  *		as the object passes from the Zone's cache to the Keg's slab.
196  *
197  *		ctor/dtor/zinit/zfini may all be null, see notes above.
198  *		Note that the zinit and zfini specified here are NOT
199  *		exactly the same as the init/fini specified to uma_zcreate()
200  *		when creating a master zone.  These zinit/zfini are called
201  *		on the TRANSITION from keg to zone (and vice-versa). Once
202  *		these are set, the primary zone may alter its init/fini
203  *		(which are called when the object passes from VM to keg)
204  *		using uma_zone_set_init/fini()) as well as its own
205  *		zinit/zfini (unset by default for master zone) with
206  *		uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
207  *
208  *	master  A reference to this zone's Master Zone (Primary Zone),
209  *		which contains the backing Keg for the Secondary Zone
210  *		being added.
211  *
212  * Returns:
213  *	A pointer to a structure which is intended to be opaque to users of
214  *	the interface.  The value may be null if the wait flag is not set.
215  */
216 uma_zone_t uma_zsecond_create(const char *name, uma_ctor ctor, uma_dtor dtor,
217     uma_init zinit, uma_fini zfini, uma_zone_t master);
218 
219 /*
220  * Create cache-only zones.
221  *
222  * This allows uma's per-cpu cache facilities to handle arbitrary
223  * pointers.  Consumers must specify the import and release functions to
224  * fill and destroy caches.  UMA does not allocate any memory for these
225  * zones.  The 'arg' parameter is passed to import/release and is caller
226  * specific.
227  */
228 uma_zone_t uma_zcache_create(const char *name, int size, uma_ctor ctor,
229     uma_dtor dtor, uma_init zinit, uma_fini zfini, uma_import zimport,
230     uma_release zrelease, void *arg, int flags);
231 
232 /*
233  * Definitions for uma_zcreate flags
234  *
235  * These flags share space with UMA_ZFLAGs in uma_int.h.  Be careful not to
236  * overlap when adding new features.
237  */
238 #define UMA_ZONE_ZINIT		0x0002	/* Initialize with zeros */
239 #define UMA_ZONE_CONTIG		0x0004	/*
240 					 * Physical memory underlying an object
241 					 * must be contiguous.
242 					 */
243 #define UMA_ZONE_NOTOUCH	0x0008	/* UMA may not access the memory */
244 #define UMA_ZONE_MALLOC		0x0010	/* For use by malloc(9) only! */
245 #define UMA_ZONE_NOFREE		0x0020	/* Do not free slabs of this type! */
246 #define UMA_ZONE_MTXCLASS	0x0040	/* Create a new lock class */
247 #define	UMA_ZONE_VM		0x0080	/*
248 					 * Used for internal vm datastructures
249 					 * only.
250 					 */
251 #define	UMA_ZONE_NOTPAGE	0x0100	/* allocf memory not vm pages */
252 #define	UMA_ZONE_SECONDARY	0x0200	/* Zone is a Secondary Zone */
253 #define	UMA_ZONE_NOBUCKET	0x0400	/* Do not use buckets. */
254 #define	UMA_ZONE_MAXBUCKET	0x0800	/* Use largest buckets. */
255 #define	UMA_ZONE_MINBUCKET	0x1000	/* Use smallest buckets. */
256 #define	UMA_ZONE_CACHESPREAD	0x2000	/*
257 					 * Spread memory start locations across
258 					 * all possible cache lines.  May
259 					 * require many virtually contiguous
260 					 * backend pages and can fail early.
261 					 */
262 #define	UMA_ZONE_NODUMP		0x4000	/*
263 					 * Zone's pages will not be included in
264 					 * mini-dumps.
265 					 */
266 #define	UMA_ZONE_PCPU		0x8000	/*
267 					 * Allocates mp_maxid + 1 slabs of
268 					 * PAGE_SIZE
269 					 */
270 #define	UMA_ZONE_FIRSTTOUCH	0x10000	/* First touch NUMA policy */
271 #define	UMA_ZONE_ROUNDROBIN	0x20000	/* Round-robin NUMA policy. */
272 #define	UMA_ZONE_SMR		0x40000 /*
273 					 * Safe memory reclamation defers
274 					 * frees until all read sections
275 					 * have exited.  This flag creates
276 					 * a unique SMR context for this
277 					 * zone.  To share contexts see
278 					 * uma_zone_set_smr() below.
279 					 *
280 					 * See sys/smr.h for more details.
281 					 */
282 /* In use by UMA_ZFLAGs:	0xffe00000 */
283 
284 /*
285  * These flags are shared between the keg and zone.  Some are determined
286  * based on physical parameters of the request and may not be provided by
287  * the consumer.
288  */
289 #define	UMA_ZONE_INHERIT						\
290     (UMA_ZONE_NOTOUCH | UMA_ZONE_MALLOC | UMA_ZONE_NOFREE |		\
291      UMA_ZONE_VM | UMA_ZONE_NOTPAGE | UMA_ZONE_PCPU |			\
292      UMA_ZONE_FIRSTTOUCH | UMA_ZONE_ROUNDROBIN)
293 
294 /* Definitions for align */
295 #define UMA_ALIGN_PTR	(sizeof(void *) - 1)	/* Alignment fit for ptr */
296 #define UMA_ALIGN_LONG	(sizeof(long) - 1)	/* "" long */
297 #define UMA_ALIGN_INT	(sizeof(int) - 1)	/* "" int */
298 #define UMA_ALIGN_SHORT	(sizeof(short) - 1)	/* "" short */
299 #define UMA_ALIGN_CHAR	(sizeof(char) - 1)	/* "" char */
300 #define UMA_ALIGN_CACHE	(0 - 1)			/* Cache line size align */
301 #define	UMA_ALIGNOF(type) (_Alignof(type) - 1)	/* Alignment fit for 'type' */
302 
303 #define	UMA_ANYDOMAIN	-1	/* Special value for domain search. */
304 
305 /*
306  * Destroys an empty uma zone.  If the zone is not empty uma complains loudly.
307  *
308  * Arguments:
309  *	zone  The zone we want to destroy.
310  *
311  */
312 void uma_zdestroy(uma_zone_t zone);
313 
314 /*
315  * Allocates an item out of a zone
316  *
317  * Arguments:
318  *	zone  The zone we are allocating from
319  *	arg   This data is passed to the ctor function
320  *	flags See sys/malloc.h for available flags.
321  *
322  * Returns:
323  *	A non-null pointer to an initialized element from the zone is
324  *	guaranteed if the wait flag is M_WAITOK.  Otherwise a null pointer
325  *	may be returned if the zone is empty or the ctor failed.
326  */
327 
328 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
329 
330 /* Allocate per-cpu data.  Access the correct data with zpcpu_get(). */
331 void *uma_zalloc_pcpu_arg(uma_zone_t zone, void *arg, int flags);
332 
333 /* Use with SMR zones. */
334 void *uma_zalloc_smr(uma_zone_t zone, int flags);
335 
336 /*
337  * Allocate an item from a specific NUMA domain.  This uses a slow path in
338  * the allocator but is guaranteed to allocate memory from the requested
339  * domain if M_WAITOK is set.
340  *
341  * Arguments:
342  *	zone  The zone we are allocating from
343  *	arg   This data is passed to the ctor function
344  *	domain The domain to allocate from.
345  *	flags See sys/malloc.h for available flags.
346  */
347 void *uma_zalloc_domain(uma_zone_t zone, void *arg, int domain, int flags);
348 
349 /*
350  * Allocates an item out of a zone without supplying an argument
351  *
352  * This is just a wrapper for uma_zalloc_arg for convenience.
353  *
354  */
355 static __inline void *uma_zalloc(uma_zone_t zone, int flags);
356 static __inline void *uma_zalloc_pcpu(uma_zone_t zone, int flags);
357 
358 static __inline void *
359 uma_zalloc(uma_zone_t zone, int flags)
360 {
361 	return uma_zalloc_arg(zone, NULL, flags);
362 }
363 
364 static __inline void *
365 uma_zalloc_pcpu(uma_zone_t zone, int flags)
366 {
367 	return uma_zalloc_pcpu_arg(zone, NULL, flags);
368 }
369 
370 /*
371  * Frees an item back into the specified zone.
372  *
373  * Arguments:
374  *	zone  The zone the item was originally allocated out of.
375  *	item  The memory to be freed.
376  *	arg   Argument passed to the destructor
377  *
378  * Returns:
379  *	Nothing.
380  */
381 
382 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
383 
384 /* Use with PCPU zones. */
385 void uma_zfree_pcpu_arg(uma_zone_t zone, void *item, void *arg);
386 
387 /* Use with SMR zones. */
388 void uma_zfree_smr(uma_zone_t zone, void *item);
389 
390 /*
391  * Frees an item back to the specified zone's domain specific pool.
392  *
393  * Arguments:
394  *	zone  The zone the item was originally allocated out of.
395  *	item  The memory to be freed.
396  *	arg   Argument passed to the destructor
397  */
398 void uma_zfree_domain(uma_zone_t zone, void *item, void *arg);
399 
400 /*
401  * Frees an item back to a zone without supplying an argument
402  *
403  * This is just a wrapper for uma_zfree_arg for convenience.
404  *
405  */
406 static __inline void uma_zfree(uma_zone_t zone, void *item);
407 static __inline void uma_zfree_pcpu(uma_zone_t zone, void *item);
408 
409 static __inline void
410 uma_zfree(uma_zone_t zone, void *item)
411 {
412 	uma_zfree_arg(zone, item, NULL);
413 }
414 
415 static __inline void
416 uma_zfree_pcpu(uma_zone_t zone, void *item)
417 {
418 	uma_zfree_pcpu_arg(zone, item, NULL);
419 }
420 
421 /*
422  * Wait until the specified zone can allocate an item.
423  */
424 void uma_zwait(uma_zone_t zone);
425 
426 /*
427  * Backend page supplier routines
428  *
429  * Arguments:
430  *	zone  The zone that is requesting pages.
431  *	size  The number of bytes being requested.
432  *	pflag Flags for these memory pages, see below.
433  *	domain The NUMA domain that we prefer for this allocation.
434  *	wait  Indicates our willingness to block.
435  *
436  * Returns:
437  *	A pointer to the allocated memory or NULL on failure.
438  */
439 
440 typedef void *(*uma_alloc)(uma_zone_t zone, vm_size_t size, int domain,
441     uint8_t *pflag, int wait);
442 
443 /*
444  * Backend page free routines
445  *
446  * Arguments:
447  *	item  A pointer to the previously allocated pages.
448  *	size  The original size of the allocation.
449  *	pflag The flags for the slab.  See UMA_SLAB_* below.
450  *
451  * Returns:
452  *	None
453  */
454 typedef void (*uma_free)(void *item, vm_size_t size, uint8_t pflag);
455 
456 /*
457  * Reclaims unused memory
458  *
459  * Arguments:
460  *	req  Reclamation request type.
461  * Returns:
462  *	None
463  */
464 #define	UMA_RECLAIM_DRAIN	1	/* release bucket cache */
465 #define	UMA_RECLAIM_DRAIN_CPU	2	/* release bucket and per-CPU caches */
466 #define	UMA_RECLAIM_TRIM	3	/* trim bucket cache to WSS */
467 void uma_reclaim(int req);
468 void uma_zone_reclaim(uma_zone_t, int req);
469 
470 /*
471  * Sets the alignment mask to be used for all zones requesting cache
472  * alignment.  Should be called by MD boot code prior to starting VM/UMA.
473  *
474  * Arguments:
475  *	align The alignment mask
476  *
477  * Returns:
478  *	Nothing
479  */
480 void uma_set_align(int align);
481 
482 /*
483  * Set a reserved number of items to hold for M_USE_RESERVE allocations.  All
484  * other requests must allocate new backing pages.
485  */
486 void uma_zone_reserve(uma_zone_t zone, int nitems);
487 
488 /*
489  * Reserves the maximum KVA space required by the zone and configures the zone
490  * to use a VM_ALLOC_NOOBJ-based backend allocator.
491  *
492  * Arguments:
493  *	zone  The zone to update.
494  *	nitems  The upper limit on the number of items that can be allocated.
495  *
496  * Returns:
497  *	0  if KVA space can not be allocated
498  *	1  if successful
499  *
500  * Discussion:
501  *	When the machine supports a direct map and the zone's items are smaller
502  *	than a page, the zone will use the direct map instead of allocating KVA
503  *	space.
504  */
505 int uma_zone_reserve_kva(uma_zone_t zone, int nitems);
506 
507 /*
508  * Sets a high limit on the number of items allowed in a zone
509  *
510  * Arguments:
511  *	zone  The zone to limit
512  *	nitems  The requested upper limit on the number of items allowed
513  *
514  * Returns:
515  *	int  The effective value of nitems
516  */
517 int uma_zone_set_max(uma_zone_t zone, int nitems);
518 
519 /*
520  * Sets a high limit on the number of items allowed in zone's bucket cache
521  *
522  * Arguments:
523  *      zone  The zone to limit
524  *      nitems  The requested upper limit on the number of items allowed
525  */
526 void uma_zone_set_maxcache(uma_zone_t zone, int nitems);
527 
528 /*
529  * Obtains the effective limit on the number of items in a zone
530  *
531  * Arguments:
532  *	zone  The zone to obtain the effective limit from
533  *
534  * Return:
535  *	0  No limit
536  *	int  The effective limit of the zone
537  */
538 int uma_zone_get_max(uma_zone_t zone);
539 
540 /*
541  * Sets a warning to be printed when limit is reached
542  *
543  * Arguments:
544  *	zone  The zone we will warn about
545  *	warning  Warning content
546  *
547  * Returns:
548  *	Nothing
549  */
550 void uma_zone_set_warning(uma_zone_t zone, const char *warning);
551 
552 /*
553  * Sets a function to run when limit is reached
554  *
555  * Arguments:
556  *	zone  The zone to which this applies
557  *	fx  The function ro run
558  *
559  * Returns:
560  *	Nothing
561  */
562 typedef void (*uma_maxaction_t)(uma_zone_t, int);
563 void uma_zone_set_maxaction(uma_zone_t zone, uma_maxaction_t);
564 
565 /*
566  * Obtains the approximate current number of items allocated from a zone
567  *
568  * Arguments:
569  *	zone  The zone to obtain the current allocation count from
570  *
571  * Return:
572  *	int  The approximate current number of items allocated from the zone
573  */
574 int uma_zone_get_cur(uma_zone_t zone);
575 
576 /*
577  * The following two routines (uma_zone_set_init/fini)
578  * are used to set the backend init/fini pair which acts on an
579  * object as it becomes allocated and is placed in a slab within
580  * the specified zone's backing keg.  These should probably not
581  * be changed once allocations have already begun, but only be set
582  * immediately upon zone creation.
583  */
584 void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
585 void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
586 
587 /*
588  * The following two routines (uma_zone_set_zinit/zfini) are
589  * used to set the zinit/zfini pair which acts on an object as
590  * it passes from the backing Keg's slab cache to the
591  * specified Zone's bucket cache.  These should probably not
592  * be changed once allocations have already begun, but only be set
593  * immediately upon zone creation.
594  */
595 void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
596 void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
597 
598 /*
599  * Replaces the standard backend allocator for this zone.
600  *
601  * Arguments:
602  *	zone   The zone whose backend allocator is being changed.
603  *	allocf A pointer to the allocation function
604  *
605  * Returns:
606  *	Nothing
607  *
608  * Discussion:
609  *	This could be used to implement pageable allocation, or perhaps
610  *	even DMA allocators if used in conjunction with the OFFPAGE
611  *	zone flag.
612  */
613 
614 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
615 
616 /*
617  * Used for freeing memory provided by the allocf above
618  *
619  * Arguments:
620  *	zone  The zone that intends to use this free routine.
621  *	freef The page freeing routine.
622  *
623  * Returns:
624  *	Nothing
625  */
626 
627 void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
628 
629 /*
630  * Associate a zone with a smr context that is allocated after creation
631  * so that multiple zones may share the same context.
632  */
633 void uma_zone_set_smr(uma_zone_t zone, smr_t smr);
634 
635 /*
636  * Fetch the smr context that was set or made in uma_zcreate().
637  */
638 smr_t uma_zone_get_smr(uma_zone_t zone);
639 
640 /*
641  * These flags are setable in the allocf and visible in the freef.
642  */
643 #define UMA_SLAB_BOOT	0x01		/* Slab alloced from boot pages */
644 #define UMA_SLAB_KERNEL	0x04		/* Slab alloced from kmem */
645 #define UMA_SLAB_PRIV	0x08		/* Slab alloced from priv allocator */
646 /* 0x02, 0x10, 0x40, and 0x80 are available */
647 
648 /*
649  * Used to pre-fill a zone with some number of items
650  *
651  * Arguments:
652  *	zone    The zone to fill
653  *	itemcnt The number of items to reserve
654  *
655  * Returns:
656  *	Nothing
657  *
658  * NOTE: This is blocking and should only be done at startup
659  */
660 void uma_prealloc(uma_zone_t zone, int itemcnt);
661 
662 /*
663  * Used to determine if a fixed-size zone is exhausted.
664  *
665  * Arguments:
666  *	zone    The zone to check
667  *
668  * Returns:
669  *	Non-zero if zone is exhausted.
670  */
671 int uma_zone_exhausted(uma_zone_t zone);
672 
673 /*
674  * Returns the bytes of memory consumed by the zone.
675  */
676 size_t uma_zone_memory(uma_zone_t zone);
677 
678 /*
679  * Common UMA_ZONE_PCPU zones.
680  */
681 extern uma_zone_t pcpu_zone_int;
682 extern uma_zone_t pcpu_zone_64;
683 
684 /*
685  * Exported statistics structures to be used by user space monitoring tools.
686  * Statistics stream consists of a uma_stream_header, followed by a series of
687  * alternative uma_type_header and uma_type_stat structures.
688  */
689 #define	UMA_STREAM_VERSION	0x00000001
690 struct uma_stream_header {
691 	uint32_t	ush_version;	/* Stream format version. */
692 	uint32_t	ush_maxcpus;	/* Value of MAXCPU for stream. */
693 	uint32_t	ush_count;	/* Number of records. */
694 	uint32_t	_ush_pad;	/* Pad/reserved field. */
695 };
696 
697 #define	UTH_MAX_NAME	32
698 #define	UTH_ZONE_SECONDARY	0x00000001
699 struct uma_type_header {
700 	/*
701 	 * Static per-zone data, some extracted from the supporting keg.
702 	 */
703 	char		uth_name[UTH_MAX_NAME];
704 	uint32_t	uth_align;	/* Keg: alignment. */
705 	uint32_t	uth_size;	/* Keg: requested size of item. */
706 	uint32_t	uth_rsize;	/* Keg: real size of item. */
707 	uint32_t	uth_maxpages;	/* Keg: maximum number of pages. */
708 	uint32_t	uth_limit;	/* Keg: max items to allocate. */
709 
710 	/*
711 	 * Current dynamic zone/keg-derived statistics.
712 	 */
713 	uint32_t	uth_pages;	/* Keg: pages allocated. */
714 	uint32_t	uth_keg_free;	/* Keg: items free. */
715 	uint32_t	uth_zone_free;	/* Zone: items free. */
716 	uint32_t	uth_bucketsize;	/* Zone: desired bucket size. */
717 	uint32_t	uth_zone_flags;	/* Zone: flags. */
718 	uint64_t	uth_allocs;	/* Zone: number of allocations. */
719 	uint64_t	uth_frees;	/* Zone: number of frees. */
720 	uint64_t	uth_fails;	/* Zone: number of alloc failures. */
721 	uint64_t	uth_sleeps;	/* Zone: number of alloc sleeps. */
722 	uint64_t	uth_xdomain;	/* Zone: Number of cross domain frees. */
723 	uint64_t	_uth_reserved1[1];	/* Reserved. */
724 };
725 
726 struct uma_percpu_stat {
727 	uint64_t	ups_allocs;	/* Cache: number of allocations. */
728 	uint64_t	ups_frees;	/* Cache: number of frees. */
729 	uint64_t	ups_cache_free;	/* Cache: free items in cache. */
730 	uint64_t	_ups_reserved[5];	/* Reserved. */
731 };
732 
733 void uma_reclaim_wakeup(void);
734 void uma_reclaim_worker(void *);
735 
736 unsigned long uma_limit(void);
737 
738 /* Return the amount of memory managed by UMA. */
739 unsigned long uma_size(void);
740 
741 /* Return the amount of memory remaining.  May be negative. */
742 long uma_avail(void);
743 
744 #endif	/* _VM_UMA_H_ */
745