diff options
Diffstat (limited to 'lib/slab.c')
| -rw-r--r-- | lib/slab.c | 40 |
1 files changed, 40 insertions, 0 deletions
@@ -8,6 +8,23 @@ * Can be freely distributed and used under the terms of the GNU GPL. */ +/** + * DOC: Slabs + * + * Slabs are collections of memory blocks of a fixed size. + * They support very fast allocation and freeing of such blocks, prevent memory + * fragmentation and optimize L2 cache usage. Slabs have been invented by Jeff Bonwick + * and published in USENIX proceedings as `The Slab Allocator: An Object-Caching Kernel + * Memory Allocator'. Our implementation follows this article except that we don't use + * constructors and destructors. + * + * When the |DEBUGGING| switch is turned on, we automatically fill all + * newly allocated and freed blocks with a special patterns to make detection + * of use of uninitialized or already freed memory easier. + * + * Example: Nodes of a FIB are allocated from a Slab. + */ + #include <stdlib.h> #include "nest/bird.h" @@ -139,6 +156,14 @@ struct sl_alignment { /* Magic structure for testing of alignment */ int x[0]; }; +/** + * sl_new - create a new Slab + * @p: resource pool + * @size: block size + * + * This function creates a new Slab resource from which + * objects of size @size can be allocated. + */ slab * sl_new(pool *p, unsigned size) { @@ -183,6 +208,13 @@ sl_new_head(slab *s) return h; } +/** + * sl_alloc - allocate an object from Slab + * @s: slab + * + * sl_alloc() allocates space for a single object from the + * Slab and returns a pointer to the object. + */ void * sl_alloc(slab *s) { @@ -223,6 +255,14 @@ no_partial: goto okay; } +/** + * sl_free - return a free object back to a Slab + * @s: slab + * @oo: object returned by sl_alloc() + * + * This function frees memory associated with the object @oo + * and returns it back to the Slab @s. + */ void sl_free(slab *s, void *oo) { |