diff options
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7a43ff774fe0..914498e8e4b9 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -153,6 +153,12 @@ struct request_queue prep_rq_fn *prep_rq_fn; /* + * The VM-level readahead tunable for this device. In + * units of 512-byte sectors. + */ + unsigned ra_sectors; + + /* * The queue owner gets to use this for whatever they like. * ll_rw_blk doesn't touch it. */ @@ -308,6 +314,8 @@ extern void blk_queue_hardsect_size(request_queue_t *q, unsigned short); extern void blk_queue_segment_boundary(request_queue_t *q, unsigned long); extern void blk_queue_assign_lock(request_queue_t *q, spinlock_t *); extern void blk_queue_prep_rq(request_queue_t *q, prep_rq_fn *pfn); +extern int blk_set_readahead(kdev_t dev, unsigned sectors); +extern unsigned blk_get_readahead(kdev_t dev); extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *); extern void blk_dump_rq_flags(struct request *, char *); @@ -322,10 +330,6 @@ extern int * blksize_size[MAX_BLKDEV]; #define MAX_SEGMENT_SIZE 65536 -/* read-ahead in pages.. */ -#define MAX_READAHEAD 31 -#define MIN_READAHEAD 3 - #define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist) extern void drive_stat_acct(struct request *, int, int); |