blk_queue_max_hw_sectors (9) - Linux Man Pages
blk_queue_max_hw_sectors: set max sectors for a request for this queue
blk_queue_max_hw_sectors - set max sectors for a request for this queue
void blk_queue_max_hw_sectors(struct request_queue
*q, unsigned int max_hw_sectors);
- the request queue for the device
- max hardware sectors in the usual 512b unit
Enables a low level driver to set a hard upper limit, max_hw_sectors, on the size of requests. max_hw_sectors is set by the device driver based upon the capabilities of the I/O controller.
max_dev_sectors is a hard limit imposed by the storage device for READ/WRITE requests. It is set by the disk driver.
max_sectors is a soft limit imposed by the block layer for filesystem type requests. This value can be overridden on a per-device basis in /sys/block/<device>/queue/max_sectors_kb. The soft limit can not exceed max_hw_sectors.