xref: /freebsd/sys/vm/uma.h (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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  * $FreeBSD$
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 void 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  */
70 typedef 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  */
88 typedef 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  *	this should be the same state that the destructor leaves the object in.
105  */
106 typedef int (*uma_init)(void *mem, int size, int flags);
107 
108 /*
109  * Item discard function
110  *
111  * Arguments:
112  * 	item  A pointer to memory which has been 'freed' but has not left the
113  *	      zone's cache.
114  *	size  The size of the item being discarded.
115  *
116  * Returns:
117  *	Nothing
118  *
119  * Discussion:
120  *	This routine is called when memory leaves a zone and is returned to the
121  *	system for other uses.  It is the counter part to the init function.
122  */
123 typedef void (*uma_fini)(void *mem, int size);
124 
125 /*
126  * What's the difference between initializing and constructing?
127  *
128  * The item is initialized when it is cached, and this is the state that the
129  * object should be in when returned to the allocator. The purpose of this is
130  * to remove some code which would otherwise be called on each allocation by
131  * utilizing a known, stable state.  This differs from the constructor which
132  * will be called on EVERY allocation.
133  *
134  * For example, in the initializer you may want to initialize embeded locks,
135  * NULL list pointers, set up initial states, magic numbers, etc.  This way if
136  * the object is held in the allocator and re-used it won't be necessary to
137  * re-initialize it.
138  *
139  * The constructor may be used to lock a data structure, link it on to lists,
140  * bump reference counts or total counts of outstanding structures, etc.
141  *
142  */
143 
144 
145 /* Function proto types */
146 
147 /*
148  * Create a new uma zone
149  *
150  * Arguments:
151  *	name  The text name of the zone for debugging and stats, this memory
152  *		should not be freed until the zone has been deallocated.
153  *	size  The size of the object that is being created.
154  *	ctor  The constructor that is called when the object is allocated
155  *	dtor  The destructor that is called when the object is freed.
156  *	init  An initializer that sets up the initial state of the memory.
157  *	fini  A discard function that undoes initialization done by init.
158  *		ctor/dtor/init/fini may all be null, see notes above.
159  *	align A bitmask that corisponds to the requested alignment
160  *		eg 4 would be 0x3
161  *	flags A set of parameters that control the behavior of the zone
162  *
163  * Returns:
164  *	A pointer to a structure which is intended to be opaque to users of
165  *	the interface.  The value may be null if the wait flag is not set.
166  */
167 uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor,
168 			uma_init uminit, uma_fini fini, int align,
169 			u_int32_t flags);
170 
171 /*
172  * Create a secondary uma zone
173  *
174  * Arguments:
175  *	name  The text name of the zone for debugging and stats, this memory
176  *		should not be freed until the zone has been deallocated.
177  *	ctor  The constructor that is called when the object is allocated
178  *	dtor  The destructor that is called when the object is freed.
179  *	zinit  An initializer that sets up the initial state of the memory
180  *		as the object passes from the Keg's slab to the Zone's cache.
181  *	zfini  A discard function that undoes initialization done by init
182  *		as the object passes from the Zone's cache to the Keg's slab.
183  *
184  *		ctor/dtor/zinit/zfini may all be null, see notes above.
185  *		Note that the zinit and zfini specified here are NOT
186  *		exactly the same as the init/fini specified to uma_zcreate()
187  *		when creating a master zone.  These zinit/zfini are called
188  *		on the TRANSITION from keg to zone (and vice-versa). Once
189  *		these are set, the primary zone may alter its init/fini
190  *		(which are called when the object passes from VM to keg)
191  *		using uma_zone_set_init/fini()) as well as its own
192  *		zinit/zfini (unset by default for master zone) with
193  *		uma_zone_set_zinit/zfini() (note subtle 'z' prefix).
194  *
195  *	master  A reference to this zone's Master Zone (Primary Zone),
196  *		which contains the backing Keg for the Secondary Zone
197  *		being added.
198  *
199  * Returns:
200  *	A pointer to a structure which is intended to be opaque to users of
201  *	the interface.  The value may be null if the wait flag is not set.
202  */
203 uma_zone_t uma_zsecond_create(char *name, uma_ctor ctor, uma_dtor dtor,
204 		    uma_init zinit, uma_fini zfini, uma_zone_t master);
205 
206 /*
207  * Definitions for uma_zcreate flags
208  *
209  * These flags share space with UMA_ZFLAGs in uma_int.h.  Be careful not to
210  * overlap when adding new features.  0xf0000000 is in use by uma_int.h.
211  */
212 #define UMA_ZONE_PAGEABLE	0x0001	/* Return items not fully backed by
213 					   physical memory XXX Not yet */
214 #define UMA_ZONE_ZINIT		0x0002	/* Initialize with zeros */
215 #define UMA_ZONE_STATIC		0x0004	/* Staticly sized zone */
216 #define UMA_ZONE_OFFPAGE	0x0008	/* Force the slab structure allocation
217 					   off of the real memory */
218 #define UMA_ZONE_MALLOC		0x0010	/* For use by malloc(9) only! */
219 #define UMA_ZONE_NOFREE		0x0020	/* Do not free slabs of this type! */
220 #define UMA_ZONE_MTXCLASS	0x0040	/* Create a new lock class */
221 #define	UMA_ZONE_VM		0x0080	/*
222 					 * Used for internal vm datastructures
223 					 * only.
224 					 */
225 #define	UMA_ZONE_HASH		0x0100	/*
226 					 * Use a hash table instead of caching
227 					 * information in the vm_page.
228 					 */
229 #define	UMA_ZONE_SECONDARY	0x0200	/* Zone is a Secondary Zone */
230 #define	UMA_ZONE_REFCNT		0x0400	/* Allocate refcnts in slabs */
231 #define	UMA_ZONE_MAXBUCKET	0x0800	/* Use largest buckets */
232 
233 /* Definitions for align */
234 #define UMA_ALIGN_PTR	(sizeof(void *) - 1)	/* Alignment fit for ptr */
235 #define UMA_ALIGN_LONG	(sizeof(long) - 1)	/* "" long */
236 #define UMA_ALIGN_INT	(sizeof(int) - 1)	/* "" int */
237 #define UMA_ALIGN_SHORT	(sizeof(short) - 1)	/* "" short */
238 #define UMA_ALIGN_CHAR	(sizeof(char) - 1)	/* "" char */
239 #define UMA_ALIGN_CACHE	(0 - 1)			/* Cache line size align */
240 
241 /*
242  * Destroys an empty uma zone.  If the zone is not empty uma complains loudly.
243  *
244  * Arguments:
245  *	zone  The zone we want to destroy.
246  *
247  */
248 void uma_zdestroy(uma_zone_t zone);
249 
250 /*
251  * Allocates an item out of a zone
252  *
253  * Arguments:
254  *	zone  The zone we are allocating from
255  *	arg   This data is passed to the ctor function
256  *	flags See sys/malloc.h for available flags.
257  *
258  * Returns:
259  *	A non null pointer to an initialized element from the zone is
260  *	garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be
261  *	returned if the zone is empty or the ctor failed.
262  */
263 
264 void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags);
265 
266 /*
267  * Allocates an item out of a zone without supplying an argument
268  *
269  * This is just a wrapper for uma_zalloc_arg for convenience.
270  *
271  */
272 static __inline void *uma_zalloc(uma_zone_t zone, int flags);
273 
274 static __inline void *
275 uma_zalloc(uma_zone_t zone, int flags)
276 {
277 	return uma_zalloc_arg(zone, NULL, flags);
278 }
279 
280 /*
281  * Frees an item back into the specified zone.
282  *
283  * Arguments:
284  *	zone  The zone the item was originally allocated out of.
285  *	item  The memory to be freed.
286  *	arg   Argument passed to the destructor
287  *
288  * Returns:
289  *	Nothing.
290  */
291 
292 void uma_zfree_arg(uma_zone_t zone, void *item, void *arg);
293 
294 /*
295  * Frees an item back to a zone without supplying an argument
296  *
297  * This is just a wrapper for uma_zfree_arg for convenience.
298  *
299  */
300 static __inline void uma_zfree(uma_zone_t zone, void *item);
301 
302 static __inline void
303 uma_zfree(uma_zone_t zone, void *item)
304 {
305 	uma_zfree_arg(zone, item, NULL);
306 }
307 
308 /*
309  * XXX The rest of the prototypes in this header are h0h0 magic for the VM.
310  * If you think you need to use it for a normal zone you're probably incorrect.
311  */
312 
313 /*
314  * Backend page supplier routines
315  *
316  * Arguments:
317  *	zone  The zone that is requesting pages
318  *	size  The number of bytes being requested
319  *	pflag Flags for these memory pages, see below.
320  *	wait  Indicates our willingness to block.
321  *
322  * Returns:
323  *	A pointer to the alloced memory or NULL on failure.
324  */
325 
326 typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait);
327 
328 /*
329  * Backend page free routines
330  *
331  * Arguments:
332  *	item  A pointer to the previously allocated pages
333  *	size  The original size of the allocation
334  *	pflag The flags for the slab.  See UMA_SLAB_* below
335  *
336  * Returns:
337  *	None
338  */
339 typedef void (*uma_free)(void *item, int size, u_int8_t pflag);
340 
341 
342 
343 /*
344  * Sets up the uma allocator. (Called by vm_mem_init)
345  *
346  * Arguments:
347  *	bootmem  A pointer to memory used to bootstrap the system.
348  *
349  * Returns:
350  *	Nothing
351  *
352  * Discussion:
353  *	This memory is used for zones which allocate things before the
354  *	backend page supplier can give us pages.  It should be
355  *	UMA_SLAB_SIZE * boot_pages bytes. (see uma_int.h)
356  *
357  */
358 
359 void uma_startup(void *bootmem, int boot_pages);
360 
361 /*
362  * Finishes starting up the allocator.  This should
363  * be called when kva is ready for normal allocs.
364  *
365  * Arguments:
366  *	None
367  *
368  * Returns:
369  *	Nothing
370  *
371  * Discussion:
372  *	uma_startup2 is called by kmeminit() to enable us of uma for malloc.
373  */
374 
375 void uma_startup2(void);
376 
377 /*
378  * Reclaims unused memory for all zones
379  *
380  * Arguments:
381  *	None
382  * Returns:
383  *	None
384  *
385  * This should only be called by the page out daemon.
386  */
387 
388 void uma_reclaim(void);
389 
390 /*
391  * Sets the alignment mask to be used for all zones requesting cache
392  * alignment.  Should be called by MD boot code prior to starting VM/UMA.
393  *
394  * Arguments:
395  *	align The alignment mask
396  *
397  * Returns:
398  *	Nothing
399  */
400 void uma_set_align(int align);
401 
402 /*
403  * Switches the backing object of a zone
404  *
405  * Arguments:
406  *	zone  The zone to update
407  *	obj   The obj to use for future allocations
408  *	size  The size of the object to allocate
409  *
410  * Returns:
411  *	0  if kva space can not be allocated
412  *	1  if successful
413  *
414  * Discussion:
415  *	A NULL object can be used and uma will allocate one for you.  Setting
416  *	the size will limit the amount of memory allocated to this zone.
417  *
418  */
419 struct vm_object;
420 int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size);
421 
422 /*
423  * Sets a high limit on the number of items allowed in a zone
424  *
425  * Arguments:
426  *	zone  The zone to limit
427  *
428  * Returns:
429  *	Nothing
430  */
431 void uma_zone_set_max(uma_zone_t zone, int nitems);
432 
433 /*
434  * The following two routines (uma_zone_set_init/fini)
435  * are used to set the backend init/fini pair which acts on an
436  * object as it becomes allocated and is placed in a slab within
437  * the specified zone's backing keg.  These should probably not
438  * be changed once allocations have already begun and only
439  * immediately upon zone creation.
440  */
441 void uma_zone_set_init(uma_zone_t zone, uma_init uminit);
442 void uma_zone_set_fini(uma_zone_t zone, uma_fini fini);
443 
444 /*
445  * The following two routines (uma_zone_set_zinit/zfini) are
446  * used to set the zinit/zfini pair which acts on an object as
447  * it passes from the backing Keg's slab cache to the
448  * specified Zone's bucket cache.  These should probably not
449  * be changed once allocations have already begun and
450  * only immediately upon zone creation.
451  */
452 void uma_zone_set_zinit(uma_zone_t zone, uma_init zinit);
453 void uma_zone_set_zfini(uma_zone_t zone, uma_fini zfini);
454 
455 /*
456  * Replaces the standard page_alloc or obj_alloc functions for this zone
457  *
458  * Arguments:
459  *	zone   The zone whos back end allocator is being changed.
460  *	allocf A pointer to the allocation function
461  *
462  * Returns:
463  *	Nothing
464  *
465  * Discussion:
466  *	This could be used to implement pageable allocation, or perhaps
467  *	even DMA allocators if used in conjunction with the OFFPAGE
468  *	zone flag.
469  */
470 
471 void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf);
472 
473 /*
474  * Used for freeing memory provided by the allocf above
475  *
476  * Arguments:
477  *	zone  The zone that intends to use this free routine.
478  *	freef The page freeing routine.
479  *
480  * Returns:
481  *	Nothing
482  */
483 
484 void uma_zone_set_freef(uma_zone_t zone, uma_free freef);
485 
486 /*
487  * These flags are setable in the allocf and visable in the freef.
488  */
489 #define UMA_SLAB_BOOT	0x01		/* Slab alloced from boot pages */
490 #define UMA_SLAB_KMEM	0x02		/* Slab alloced from kmem_map */
491 #define UMA_SLAB_KERNEL	0x04		/* Slab alloced from kernel_map */
492 #define UMA_SLAB_PRIV	0x08		/* Slab alloced from priv allocator */
493 #define UMA_SLAB_OFFP	0x10		/* Slab is managed separately  */
494 #define UMA_SLAB_MALLOC	0x20		/* Slab is a large malloc slab */
495 /* 0x40 and 0x80 are available */
496 
497 /*
498  * Used to pre-fill a zone with some number of items
499  *
500  * Arguments:
501  *	zone    The zone to fill
502  *	itemcnt The number of items to reserve
503  *
504  * Returns:
505  *	Nothing
506  *
507  * NOTE: This is blocking and should only be done at startup
508  */
509 void uma_prealloc(uma_zone_t zone, int itemcnt);
510 
511 /*
512  * Used to lookup the reference counter allocated for an item
513  * from a UMA_ZONE_REFCNT zone.  For UMA_ZONE_REFCNT zones,
514  * reference counters are allocated for items and stored in
515  * the underlying slab header.
516  *
517  * Arguments:
518  * 	zone  The UMA_ZONE_REFCNT zone to which the item belongs.
519  *	item  The address of the item for which we want a refcnt.
520  *
521  * Returns:
522  * 	A pointer to a u_int32_t reference counter.
523  */
524 u_int32_t *uma_find_refcnt(uma_zone_t zone, void *item);
525 
526 /*
527  * Used to determine if a fixed-size zone is exhausted.
528  *
529  * Arguments:
530  *	zone    The zone to check
531  *
532  * Returns:
533  * 	Non-zero if zone is exhausted.
534  */
535 int uma_zone_exhausted(uma_zone_t zone);
536 int uma_zone_exhausted_nolock(uma_zone_t zone);
537 
538 /*
539  * Exported statistics structures to be used by user space monitoring tools.
540  * Statistics stream consusts of a uma_stream_header, followed by a series of
541  * alternative uma_type_header and uma_type_stat structures.  Statistics
542  * structures
543  */
544 #define	UMA_STREAM_VERSION	0x00000001
545 struct uma_stream_header {
546 	u_int32_t	ush_version;	/* Stream format version. */
547 	u_int32_t	ush_maxcpus;	/* Value of MAXCPU for stream. */
548 	u_int32_t	ush_count;	/* Number of records. */
549 	u_int32_t	_ush_pad;	/* Pad/reserved field. */
550 };
551 
552 #define	UTH_MAX_NAME	32
553 #define	UTH_ZONE_SECONDARY	0x00000001
554 struct uma_type_header {
555 	/*
556 	 * Static per-zone data, some extracted from the supporting keg.
557 	 */
558 	char		uth_name[UTH_MAX_NAME];
559 	u_int32_t	uth_align;	/* Keg: alignment. */
560 	u_int32_t	uth_size;	/* Keg: requested size of item. */
561 	u_int32_t	uth_rsize;	/* Keg: real size of item. */
562 	u_int32_t	uth_maxpages;	/* Keg: maximum number of pages. */
563 	u_int32_t	uth_limit;	/* Keg: max items to allocate. */
564 
565 	/*
566 	 * Current dynamic zone/keg-derived statistics.
567 	 */
568 	u_int32_t	uth_pages;	/* Keg: pages allocated. */
569 	u_int32_t	uth_keg_free;	/* Keg: items free. */
570 	u_int32_t	uth_zone_free;	/* Zone: items free. */
571 	u_int32_t	uth_bucketsize;	/* Zone: desired bucket size. */
572 	u_int32_t	uth_zone_flags;	/* Zone: flags. */
573 	u_int64_t	uth_allocs;	/* Zone: number of allocations. */
574 	u_int64_t	uth_frees;	/* Zone: number of frees. */
575 	u_int64_t	uth_fails;	/* Zone: number of alloc failures. */
576 	u_int64_t	_uth_reserved1[3];	/* Reserved. */
577 };
578 
579 struct uma_percpu_stat {
580 	u_int64_t	ups_allocs;	/* Cache: number of alloctions. */
581 	u_int64_t	ups_frees;	/* Cache: number of frees. */
582 	u_int64_t	ups_cache_free;	/* Cache: free items in cache. */
583 	u_int64_t	_ups_reserved[5];	/* Reserved. */
584 };
585 
586 #endif
587