diff options
Diffstat (limited to 'include/linux/sbitmap.h')
| -rw-r--r-- | include/linux/sbitmap.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 841585f6e5f2..0c4a9c242dd7 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -127,6 +127,12 @@ struct sbitmap_queue { * @round_robin: Allocate bits in strict round-robin order. */ bool round_robin; + + /** + * @min_shallow_depth: The minimum shallow depth which may be passed to + * sbitmap_queue_get_shallow() or __sbitmap_queue_get_shallow(). + */ + unsigned int min_shallow_depth; }; /** @@ -390,6 +396,9 @@ int __sbitmap_queue_get(struct sbitmap_queue *sbq); * @shallow_depth: The maximum number of bits to allocate from a single word. * See sbitmap_get_shallow(). * + * If you call this, make sure to call sbitmap_queue_min_shallow_depth() after + * initializing @sbq. + * * Return: Non-negative allocated bit number if successful, -1 otherwise. */ int __sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, @@ -424,6 +433,9 @@ static inline int sbitmap_queue_get(struct sbitmap_queue *sbq, * @shallow_depth: The maximum number of bits to allocate from a single word. * See sbitmap_get_shallow(). * + * If you call this, make sure to call sbitmap_queue_min_shallow_depth() after + * initializing @sbq. + * * Return: Non-negative allocated bit number if successful, -1 otherwise. */ static inline int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, @@ -439,6 +451,23 @@ static inline int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, } /** + * sbitmap_queue_min_shallow_depth() - Inform a &struct sbitmap_queue of the + * minimum shallow depth that will be used. + * @sbq: Bitmap queue in question. + * @min_shallow_depth: The minimum shallow depth that will be passed to + * sbitmap_queue_get_shallow() or __sbitmap_queue_get_shallow(). + * + * sbitmap_queue_clear() batches wakeups as an optimization. The batch size + * depends on the depth of the bitmap. Since the shallow allocation functions + * effectively operate with a different depth, the shallow depth must be taken + * into account when calculating the batch size. This function must be called + * with the minimum shallow depth that will be used. Failure to do so can result + * in missed wakeups. + */ +void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq, + unsigned int min_shallow_depth); + +/** * sbitmap_queue_clear() - Free an allocated bit and wake up waiters on a * &struct sbitmap_queue. * @sbq: Bitmap to free from. |