diff options
| -rw-r--r-- | include/linux/mempool.h | 1 | ||||
| -rw-r--r-- | mm/mempool.c | 37 |
2 files changed, 38 insertions, 0 deletions
diff --git a/include/linux/mempool.h b/include/linux/mempool.h index 4aae6c06c5f2..7be1e32e6d42 100644 --- a/include/linux/mempool.h +++ b/include/linux/mempool.h @@ -51,6 +51,7 @@ extern mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn, extern int mempool_resize(mempool_t *pool, int new_min_nr); extern void mempool_destroy(mempool_t *pool); extern void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask) __malloc; +extern void *mempool_alloc_preallocated(mempool_t *pool) __malloc; extern void mempool_free(void *element, mempool_t *pool); /* diff --git a/mm/mempool.c b/mm/mempool.c index 103dc4770cfb..cb7b4b56cec1 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -457,6 +457,43 @@ repeat_alloc: EXPORT_SYMBOL(mempool_alloc); /** + * mempool_alloc_preallocated - allocate an element from preallocated elements + * belonging to a specific memory pool + * @pool: pointer to the memory pool which was allocated via + * mempool_create(). + * + * This function is similar to mempool_alloc, but it only attempts allocating + * an element from the preallocated elements. It does not sleep and immediately + * returns if no preallocated elements are available. + * + * Return: pointer to the allocated element or %NULL if no elements are + * available. + */ +void *mempool_alloc_preallocated(mempool_t *pool) +{ + void *element; + unsigned long flags; + + spin_lock_irqsave(&pool->lock, flags); + if (likely(pool->curr_nr)) { + element = remove_element(pool); + spin_unlock_irqrestore(&pool->lock, flags); + /* paired with rmb in mempool_free(), read comment there */ + smp_wmb(); + /* + * Update the allocation stack trace as this is more useful + * for debugging. + */ + kmemleak_update_trace(element); + return element; + } + spin_unlock_irqrestore(&pool->lock, flags); + + return NULL; +} +EXPORT_SYMBOL(mempool_alloc_preallocated); + +/** * mempool_free - return an element to the pool. * @element: pool element pointer. * @pool: pointer to the memory pool which was allocated via |