mempool: Add mempool_init()/mempool_exit()

Allows mempools to be embedded in other structs, getting rid of a
pointer indirection from allocation fastpaths.

mempool_exit() is safe to call on an uninitialized but zeroed mempool.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Kent Overstreet 2015-05-04 16:52:20 -07:00 committed by Jens Axboe
parent c854ab5773
commit c1a67fefd0
2 changed files with 115 additions and 27 deletions

View File

@ -25,6 +25,18 @@ typedef struct mempool_s {
wait_queue_head_t wait;
} mempool_t;
static inline bool mempool_initialized(mempool_t *pool)
{
return pool->elements != NULL;
}
void mempool_exit(mempool_t *pool);
int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data,
gfp_t gfp_mask, int node_id);
int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data);
extern mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data);
extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
@ -43,6 +55,14 @@ extern void mempool_free(void *element, mempool_t *pool);
*/
void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data);
void mempool_free_slab(void *element, void *pool_data);
static inline int
mempool_init_slab_pool(mempool_t *pool, int min_nr, struct kmem_cache *kc)
{
return mempool_init(pool, min_nr, mempool_alloc_slab,
mempool_free_slab, (void *) kc);
}
static inline mempool_t *
mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
{
@ -56,6 +76,13 @@ mempool_create_slab_pool(int min_nr, struct kmem_cache *kc)
*/
void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data);
void mempool_kfree(void *element, void *pool_data);
static inline int mempool_init_kmalloc_pool(mempool_t *pool, int min_nr, size_t size)
{
return mempool_init(pool, min_nr, mempool_kmalloc,
mempool_kfree, (void *) size);
}
static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
{
return mempool_create(min_nr, mempool_kmalloc, mempool_kfree,
@ -68,6 +95,13 @@ static inline mempool_t *mempool_create_kmalloc_pool(int min_nr, size_t size)
*/
void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data);
void mempool_free_pages(void *element, void *pool_data);
static inline int mempool_init_page_pool(mempool_t *pool, int min_nr, int order)
{
return mempool_init(pool, min_nr, mempool_alloc_pages,
mempool_free_pages, (void *)(long)order);
}
static inline mempool_t *mempool_create_page_pool(int min_nr, int order)
{
return mempool_create(min_nr, mempool_alloc_pages, mempool_free_pages,

View File

@ -137,6 +137,28 @@ static void *remove_element(mempool_t *pool, gfp_t flags)
return element;
}
/**
* mempool_exit - exit a mempool initialized with mempool_init()
* @pool: pointer to the memory pool which was initialized with
* mempool_init().
*
* Free all reserved elements in @pool and @pool itself. This function
* only sleeps if the free_fn() function sleeps.
*
* May be called on a zeroed but uninitialized mempool (i.e. allocated with
* kzalloc()).
*/
void mempool_exit(mempool_t *pool)
{
while (pool->curr_nr) {
void *element = remove_element(pool, GFP_KERNEL);
pool->free(element, pool->pool_data);
}
kfree(pool->elements);
pool->elements = NULL;
}
EXPORT_SYMBOL(mempool_exit);
/**
* mempool_destroy - deallocate a memory pool
* @pool: pointer to the memory pool which was allocated via
@ -150,15 +172,65 @@ void mempool_destroy(mempool_t *pool)
if (unlikely(!pool))
return;
while (pool->curr_nr) {
void *element = remove_element(pool, GFP_KERNEL);
pool->free(element, pool->pool_data);
}
kfree(pool->elements);
mempool_exit(pool);
kfree(pool);
}
EXPORT_SYMBOL(mempool_destroy);
int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data,
gfp_t gfp_mask, int node_id)
{
spin_lock_init(&pool->lock);
pool->min_nr = min_nr;
pool->pool_data = pool_data;
pool->alloc = alloc_fn;
pool->free = free_fn;
init_waitqueue_head(&pool->wait);
pool->elements = kmalloc_array_node(min_nr, sizeof(void *),
gfp_mask, node_id);
if (!pool->elements)
return -ENOMEM;
/*
* First pre-allocate the guaranteed number of buffers.
*/
while (pool->curr_nr < pool->min_nr) {
void *element;
element = pool->alloc(gfp_mask, pool->pool_data);
if (unlikely(!element)) {
mempool_exit(pool);
return -ENOMEM;
}
add_element(pool, element);
}
return 0;
}
EXPORT_SYMBOL(mempool_init_node);
/**
* mempool_init - initialize a memory pool
* @min_nr: the minimum number of elements guaranteed to be
* allocated for this pool.
* @alloc_fn: user-defined element-allocation function.
* @free_fn: user-defined element-freeing function.
* @pool_data: optional private data available to the user-defined functions.
*
* Like mempool_create(), but initializes the pool in (i.e. embedded in another
* structure).
*/
int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data)
{
return mempool_init_node(pool, min_nr, alloc_fn, free_fn,
pool_data, GFP_KERNEL, NUMA_NO_NODE);
}
EXPORT_SYMBOL(mempool_init);
/**
* mempool_create - create a memory pool
* @min_nr: the minimum number of elements guaranteed to be
@ -186,35 +258,17 @@ mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
gfp_t gfp_mask, int node_id)
{
mempool_t *pool;
pool = kzalloc_node(sizeof(*pool), gfp_mask, node_id);
if (!pool)
return NULL;
pool->elements = kmalloc_array_node(min_nr, sizeof(void *),
gfp_mask, node_id);
if (!pool->elements) {
if (mempool_init_node(pool, min_nr, alloc_fn, free_fn, pool_data,
gfp_mask, node_id)) {
kfree(pool);
return NULL;
}
spin_lock_init(&pool->lock);
pool->min_nr = min_nr;
pool->pool_data = pool_data;
init_waitqueue_head(&pool->wait);
pool->alloc = alloc_fn;
pool->free = free_fn;
/*
* First pre-allocate the guaranteed number of buffers.
*/
while (pool->curr_nr < pool->min_nr) {
void *element;
element = pool->alloc(gfp_mask, pool->pool_data);
if (unlikely(!element)) {
mempool_destroy(pool);
return NULL;
}
add_element(pool, element);
}
return pool;
}
EXPORT_SYMBOL(mempool_create_node);