blk_queue_io_opt (9)

void blk_queue_io_opt(struct request_queue * q, unsigned int opt);

q

the request queue for the device

opt

optimal request size in bytes

Storage devices may report an optimal I/O size, which is the device's preferred unit for sustained I/O. This is rarely reported for disk drives. For RAID arrays it is usually the stripe width or the internal track size. A properly aligned multiple of optimal_io_size is the preferred request size for workloads where sustained throughput is desired.