uma.h revision 120223
168349Sobrien/* 268349Sobrien * Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org> 368349Sobrien * All rights reserved. 468349Sobrien * 568349Sobrien * Redistribution and use in source and binary forms, with or without 668349Sobrien * modification, are permitted provided that the following conditions 768349Sobrien * are met: 868349Sobrien * 1. Redistributions of source code must retain the above copyright 968349Sobrien * notice unmodified, this list of conditions, and the following 1068349Sobrien * disclaimer. 1168349Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1268349Sobrien * notice, this list of conditions and the following disclaimer in the 1368349Sobrien * documentation and/or other materials provided with the distribution. 1468349Sobrien * 1568349Sobrien * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1668349Sobrien * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1768349Sobrien * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1868349Sobrien * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1968349Sobrien * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 2068349Sobrien * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2168349Sobrien * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2268349Sobrien * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2368349Sobrien * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2468349Sobrien * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2568349Sobrien * 2668349Sobrien * $FreeBSD: head/sys/vm/uma.h 120223 2003-09-19 08:37:44Z jeff $ 2768349Sobrien * 2868349Sobrien */ 2968349Sobrien 3068349Sobrien/* 3168349Sobrien * uma.h - External definitions for the Universal Memory Allocator 3268349Sobrien * 3368349Sobrien*/ 3468349Sobrien 3568349Sobrien#ifndef VM_UMA_H 3668349Sobrien#define VM_UMA_H 3768349Sobrien 3868349Sobrien#include <sys/param.h> /* For NULL */ 3968349Sobrien#include <sys/malloc.h> /* For M_* */ 4068349Sobrien 4168349Sobrien/* User visable parameters */ 4268349Sobrien#define UMA_SMALLEST_UNIT (PAGE_SIZE / 256) /* Smallest item allocated */ 4368349Sobrien 4468349Sobrien/* Types and type defs */ 4568349Sobrien 4668349Sobrienstruct uma_zone; 4768349Sobrien/* Opaque type used as a handle to the zone */ 4868349Sobrientypedef struct uma_zone * uma_zone_t; 4968349Sobrien 5068349Sobrien/* 5168349Sobrien * Item constructor 5268349Sobrien * 5368349Sobrien * Arguments: 5468349Sobrien * item A pointer to the memory which has been allocated. 5568349Sobrien * arg The arg field passed to uma_zalloc_arg 5668349Sobrien * size The size of the allocated item 5768349Sobrien * 5868349Sobrien * Returns: 5968349Sobrien * Nothing 6068349Sobrien * 6168349Sobrien * Discussion: 6268349Sobrien * The constructor is called just before the memory is returned 6368349Sobrien * to the user. It may block if necessary. 6468349Sobrien */ 6568349Sobrientypedef void (*uma_ctor)(void *mem, int size, void *arg); 6668349Sobrien 6768349Sobrien/* 6868349Sobrien * Item destructor 6968349Sobrien * 7068349Sobrien * Arguments: 7168349Sobrien * item A pointer to the memory which has been allocated. 7268349Sobrien * size The size of the item being destructed. 7368349Sobrien * arg Argument passed through uma_zfree_arg 7468349Sobrien * 7568349Sobrien * Returns: 7668349Sobrien * Nothing 7768349Sobrien * 7868349Sobrien * Discussion: 7968349Sobrien * The destructor may perform operations that differ from those performed 8068349Sobrien * by the initializer, but it must leave the object in the same state. 8168349Sobrien * This IS type stable storage. This is called after EVERY zfree call. 8268349Sobrien */ 8368349Sobrientypedef void (*uma_dtor)(void *mem, int size, void *arg); 8468349Sobrien 8568349Sobrien/* 86133359Sobrien * Item initializer 8768349Sobrien * 8868349Sobrien * Arguments: 89103373Sobrien * item A pointer to the memory which has been allocated. 90103373Sobrien * size The size of the item being initialized. 91103373Sobrien * 92103373Sobrien * Returns: 93133359Sobrien * Nothing 94133359Sobrien * 95133359Sobrien * Discussion: 96133359Sobrien * The initializer is called when the memory is cached in the uma zone. 97133359Sobrien * this should be the same state that the destructor leaves the object in. 98133359Sobrien */ 99133359Sobrientypedef void (*uma_init)(void *mem, int size); 100133359Sobrien 101133359Sobrien/* 102133359Sobrien * Item discard function 103133359Sobrien * 104133359Sobrien * Arguments: 105133359Sobrien * item A pointer to memory which has been 'freed' but has not left the 106133359Sobrien * zone's cache. 107133359Sobrien * size The size of the item being discarded. 108133359Sobrien * 109133359Sobrien * Returns: 110133359Sobrien * Nothing 111133359Sobrien * 112133359Sobrien * Discussion: 113133359Sobrien * This routine is called when memory leaves a zone and is returned to the 114133359Sobrien * system for other uses. It is the counter part to the init function. 115133359Sobrien */ 116133359Sobrientypedef void (*uma_fini)(void *mem, int size); 117159764Sobrien 118159764Sobrien/* 119159764Sobrien * What's the difference between initializing and constructing? 120159764Sobrien * 121 * The item is initialized when it is cached, and this is the state that the 122 * object should be in when returned to the allocator. The purpose of this is 123 * to remove some code which would otherwise be called on each allocation by 124 * utilizing a known, stable state. This differs from the constructor which 125 * will be called on EVERY allocation. 126 * 127 * For example, in the initializer you may want to initialize embeded locks, 128 * NULL list pointers, set up initial states, magic numbers, etc. This way if 129 * the object is held in the allocator and re-used it won't be necessary to 130 * re-initialize it. 131 * 132 * The constructor may be used to lock a data structure, link it on to lists, 133 * bump reference counts or total counts of outstanding structures, etc. 134 * 135 */ 136 137 138/* Function proto types */ 139 140/* 141 * Create a new uma zone 142 * 143 * Arguments: 144 * name The text name of the zone for debugging and stats, this memory 145 * should not be freed until the zone has been deallocated. 146 * size The size of the object that is being created. 147 * ctor The constructor that is called when the object is allocated 148 * dtor The destructor that is called when the object is freed. 149 * init An initializer that sets up the initial state of the memory. 150 * fini A discard function that undoes initialization done by init. 151 * ctor/dtor/init/fini may all be null, see notes above. 152 * align A bitmask that corisponds to the requested alignment 153 * eg 4 would be 0x3 154 * flags A set of parameters that control the behavior of the zone 155 * 156 * Returns: 157 * A pointer to a structure which is intended to be opaque to users of 158 * the interface. The value may be null if the wait flag is not set. 159 */ 160 161uma_zone_t uma_zcreate(char *name, size_t size, uma_ctor ctor, uma_dtor dtor, 162 uma_init uminit, uma_fini fini, int align, 163 u_int16_t flags); 164 165/* 166 * Definitions for uma_zcreate flags 167 * 168 * These flags share space with UMA_ZFLAGs in uma_int.h. Be careful not to 169 * overlap when adding new features. 0xf000 is in use by uma_int.h. 170 */ 171#define UMA_ZONE_PAGEABLE 0x0001 /* Return items not fully backed by 172 physical memory XXX Not yet */ 173#define UMA_ZONE_ZINIT 0x0002 /* Initialize with zeros */ 174#define UMA_ZONE_STATIC 0x0004 /* Staticly sized zone */ 175#define UMA_ZONE_OFFPAGE 0x0008 /* Force the slab structure allocation 176 off of the real memory */ 177#define UMA_ZONE_MALLOC 0x0010 /* For use by malloc(9) only! */ 178#define UMA_ZONE_NOFREE 0x0020 /* Do not free slabs of this type! */ 179#define UMA_ZONE_MTXCLASS 0x0040 /* Create a new lock class */ 180#define UMA_ZONE_VM 0x0080 /* 181 * Used for internal vm datastructures 182 * only. 183 */ 184#define UMA_ZONE_HASH 0x0100 /* 185 * Use a hash table instead of caching 186 * information in the vm_page. 187 */ 188 189/* Definitions for align */ 190#define UMA_ALIGN_PTR (sizeof(void *) - 1) /* Alignment fit for ptr */ 191#define UMA_ALIGN_LONG (sizeof(long) - 1) /* "" long */ 192#define UMA_ALIGN_INT (sizeof(int) - 1) /* "" int */ 193#define UMA_ALIGN_SHORT (sizeof(short) - 1) /* "" short */ 194#define UMA_ALIGN_CHAR (sizeof(char) - 1) /* "" char */ 195#define UMA_ALIGN_CACHE (16 - 1) /* Cache line size align */ 196 197/* 198 * Destroys an empty uma zone. If the zone is not empty uma complains loudly. 199 * 200 * Arguments: 201 * zone The zone we want to destroy. 202 * 203 */ 204 205void uma_zdestroy(uma_zone_t zone); 206 207/* 208 * Allocates an item out of a zone 209 * 210 * Arguments: 211 * zone The zone we are allocating from 212 * arg This data is passed to the ctor function 213 * flags See sys/malloc.h for available flags. 214 * 215 * Returns: 216 * A non null pointer to an initialized element from the zone is 217 * garanteed if the wait flag is M_WAITOK, otherwise a null pointer may be 218 * returned if the zone is empty or the ctor failed. 219 */ 220 221void *uma_zalloc_arg(uma_zone_t zone, void *arg, int flags); 222 223/* 224 * Allocates an item out of a zone without supplying an argument 225 * 226 * This is just a wrapper for uma_zalloc_arg for convenience. 227 * 228 */ 229static __inline void *uma_zalloc(uma_zone_t zone, int flags); 230 231static __inline void * 232uma_zalloc(uma_zone_t zone, int flags) 233{ 234 return uma_zalloc_arg(zone, NULL, flags); 235} 236 237/* 238 * Frees an item back into the specified zone. 239 * 240 * Arguments: 241 * zone The zone the item was originally allocated out of. 242 * item The memory to be freed. 243 * arg Argument passed to the destructor 244 * 245 * Returns: 246 * Nothing. 247 */ 248 249void uma_zfree_arg(uma_zone_t zone, void *item, void *arg); 250 251/* 252 * Frees an item back to a zone without supplying an argument 253 * 254 * This is just a wrapper for uma_zfree_arg for convenience. 255 * 256 */ 257static __inline void uma_zfree(uma_zone_t zone, void *item); 258 259static __inline void 260uma_zfree(uma_zone_t zone, void *item) 261{ 262 uma_zfree_arg(zone, item, NULL); 263} 264 265/* 266 * XXX The rest of the prototypes in this header are h0h0 magic for the VM. 267 * If you think you need to use it for a normal zone you're probably incorrect. 268 */ 269 270/* 271 * Backend page supplier routines 272 * 273 * Arguments: 274 * zone The zone that is requesting pages 275 * size The number of bytes being requested 276 * pflag Flags for these memory pages, see below. 277 * wait Indicates our willingness to block. 278 * 279 * Returns: 280 * A pointer to the alloced memory or NULL on failure. 281 */ 282 283typedef void *(*uma_alloc)(uma_zone_t zone, int size, u_int8_t *pflag, int wait); 284 285/* 286 * Backend page free routines 287 * 288 * Arguments: 289 * item A pointer to the previously allocated pages 290 * size The original size of the allocation 291 * pflag The flags for the slab. See UMA_SLAB_* below 292 * 293 * Returns: 294 * None 295 */ 296typedef void (*uma_free)(void *item, int size, u_int8_t pflag); 297 298 299 300/* 301 * Sets up the uma allocator. (Called by vm_mem_init) 302 * 303 * Arguments: 304 * bootmem A pointer to memory used to bootstrap the system. 305 * 306 * Returns: 307 * Nothing 308 * 309 * Discussion: 310 * This memory is used for zones which allocate things before the 311 * backend page supplier can give us pages. It should be 312 * UMA_SLAB_SIZE * UMA_BOOT_PAGES bytes. (see uma_int.h) 313 * 314 */ 315 316void uma_startup(void *bootmem); 317 318/* 319 * Finishes starting up the allocator. This should 320 * be called when kva is ready for normal allocs. 321 * 322 * Arguments: 323 * None 324 * 325 * Returns: 326 * Nothing 327 * 328 * Discussion: 329 * uma_startup2 is called by kmeminit() to enable us of uma for malloc. 330 */ 331 332void uma_startup2(void); 333 334/* 335 * Reclaims unused memory for all zones 336 * 337 * Arguments: 338 * None 339 * Returns: 340 * None 341 * 342 * This should only be called by the page out daemon. 343 */ 344 345void uma_reclaim(void); 346 347/* 348 * Switches the backing object of a zone 349 * 350 * Arguments: 351 * zone The zone to update 352 * obj The obj to use for future allocations 353 * size The size of the object to allocate 354 * 355 * Returns: 356 * 0 if kva space can not be allocated 357 * 1 if successful 358 * 359 * Discussion: 360 * A NULL object can be used and uma will allocate one for you. Setting 361 * the size will limit the amount of memory allocated to this zone. 362 * 363 */ 364struct vm_object; 365int uma_zone_set_obj(uma_zone_t zone, struct vm_object *obj, int size); 366 367/* 368 * Sets a high limit on the number of items allowed in a zone 369 * 370 * Arguments: 371 * zone The zone to limit 372 * 373 * Returns: 374 * Nothing 375 */ 376void uma_zone_set_max(uma_zone_t zone, int nitems); 377 378/* 379 * Replaces the standard page_alloc or obj_alloc functions for this zone 380 * 381 * Arguments: 382 * zone The zone whos back end allocator is being changed. 383 * allocf A pointer to the allocation function 384 * 385 * Returns: 386 * Nothing 387 * 388 * Discussion: 389 * This could be used to implement pageable allocation, or perhaps 390 * even DMA allocators if used in conjunction with the OFFPAGE 391 * zone flag. 392 */ 393 394void uma_zone_set_allocf(uma_zone_t zone, uma_alloc allocf); 395 396/* 397 * Used for freeing memory provided by the allocf above 398 * 399 * Arguments: 400 * zone The zone that intends to use this free routine. 401 * freef The page freeing routine. 402 * 403 * Returns: 404 * Nothing 405 */ 406 407void uma_zone_set_freef(uma_zone_t zone, uma_free freef); 408 409/* 410 * These flags are setable in the allocf and visable in the freef. 411 */ 412#define UMA_SLAB_BOOT 0x01 /* Slab alloced from boot pages */ 413#define UMA_SLAB_KMEM 0x02 /* Slab alloced from kmem_map */ 414#define UMA_SLAB_PRIV 0x08 /* Slab alloced from priv allocator */ 415#define UMA_SLAB_OFFP 0x10 /* Slab is managed separately */ 416#define UMA_SLAB_MALLOC 0x20 /* Slab is a large malloc slab */ 417/* 0x40 and 0x80 are available */ 418 419/* 420 * Used to pre-fill a zone with some number of items 421 * 422 * Arguments: 423 * zone The zone to fill 424 * itemcnt The number of items to reserve 425 * 426 * Returns: 427 * Nothing 428 * 429 * NOTE: This is blocking and should only be done at startup 430 */ 431void uma_prealloc(uma_zone_t zone, int itemcnt); 432 433 434#endif 435