kernel/generic/include/mm/slab.h

   1 /*
   2  * Copyright (C) 2006 Ondrej Palkovsky
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup genericmm
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #ifndef KERN_SLAB_H_
  36 #define KERN_SLAB_H_
  37
  38 #include <adt/list.h>
  39 #include <synch/spinlock.h>
  40 #include <atomic.h>
  41 #include <mm/frame.h>
  42
  43 /** Minimum size to be allocated by malloc */
  44 #define SLAB_MIN_MALLOC_W 4
  45
  46 /** Maximum size to be allocated by malloc */
  47 #define SLAB_MAX_MALLOC_W 18
  48
  49 /** Initial Magazine size (TODO: dynamically growing magazines) */
  50 #define SLAB_MAG_SIZE  4
  51
  52 /** If object size is less, store control structure inside SLAB */
  53 #define SLAB_INSIDE_SIZE   (PAGE_SIZE >> 3)
  54
  55 /** Maximum wasted space we allow for cache */
  56 #define SLAB_MAX_BADNESS(cache)   ((PAGE_SIZE << (cache)->order) >> 2)
  57
  58 /* slab_reclaim constants */
  59 #define SLAB_RECLAIM_ALL  0x1 /**< Reclaim all possible memory, because we are in memory stress */
  60
  61 /* cache_create flags */
  62 #define SLAB_CACHE_NOMAGAZINE 0x1 /**< Do not use per-cpu cache */
  63 #define SLAB_CACHE_SLINSIDE   0x2 /**< Have control structure inside SLAB */
  64 #define SLAB_CACHE_MAGDEFERRED (0x4 | SLAB_CACHE_NOMAGAZINE) /**< We add magazine cache later, if we have this flag */
  65
  66 typedef struct {
  67         link_t link;
  68         count_t busy;  /**< Count of full slots in magazine */
  69         count_t size;  /**< Number of slots in magazine */
  70         void *objs[0]; /**< Slots in magazine */
  71 }slab_magazine_t;
  72
  73 typedef struct {
  74         slab_magazine_t *current;
  75         slab_magazine_t *last;
  76         SPINLOCK_DECLARE(lock);
  77 }slab_mag_cache_t;
  78
  79
  80 typedef struct {
  81         char *name;
  82
  83         link_t link;
  84         /* Configuration */
  85         size_t size;      /**< Size of slab position - align_up(sizeof(obj)) */
  86         int (*constructor)(void *obj, int kmflag);
  87         int (*destructor)(void *obj);
  88         int flags;        /**< Flags changing behaviour of cache */
  89
  90         /* Computed values */
  91         uint8_t order;        /**< Order of frames to be allocated */
  92         int objects;      /**< Number of objects that fit in */
  93
  94         /* Statistics */
  95         atomic_t allocated_slabs;
  96         atomic_t allocated_objs;
  97         atomic_t cached_objs;
  98         atomic_t magazine_counter; /**< How many magazines in magazines list */
  99
 100         /* Slabs */
 101         link_t full_slabs;     /**< List of full slabs */
 102         link_t partial_slabs;  /**< List of partial slabs */
 103         SPINLOCK_DECLARE(slablock);
 104         /* Magazines  */
 105         link_t magazines;      /**< List o full magazines */
 106         SPINLOCK_DECLARE(maglock);
 107
 108         /** CPU cache */
 109         slab_mag_cache_t *mag_cache;
 110 }slab_cache_t;
 111
 112 extern slab_cache_t * slab_cache_create(char *name,
 113                                         size_t size,
 114                                         size_t align,
 115                                         int (*constructor)(void *obj, int kmflag),
 116                                         int (*destructor)(void *obj),
 117                                         int flags);
 118 extern void slab_cache_destroy(slab_cache_t *cache);
 119
 120 extern void * slab_alloc(slab_cache_t *cache, int flags);
 121 extern void slab_free(slab_cache_t *cache, void *obj);
 122 extern count_t slab_reclaim(int flags);
 123
 124 /** Initialize slab subsytem */
 125 extern void slab_cache_init(void);
 126 extern void slab_enable_cpucache(void);
 127
 128 /* kconsole debug */
 129 extern void slab_print_list(void);
 130
 131 /* malloc support */
 132 extern void * malloc(unsigned int size, int flags);
 133 extern void free(void *obj);
 134 #endif
 135
 136 /** @}
 137  */