scsi: smartpqi: Add stream detection

Enhance performance by adding sequential stream detection for RAID5/RAID6
sequential write requests. Reduce stripe lock contention with full-stripe
write operations.

There is one common stripe lock for each RAID volume that can be set by
either the RAID engine or the AIO engine. The AIO path has I/O request
sizes well below the stripe size resulting in many Read-Modify-Write
operations.

Sending the request to the RAID engine allows for coalescing requests into
full stripe operations resulting in reduced Read-Modify-Write operations.

Link: https://lore.kernel.org/r/161549375693.25025.2962141451773219796.stgit@brunhilda
Reviewed-by: Scott Benesh <[email protected]>
Reviewed-by: Mike McGowen <[email protected]>
Reviewed-by: Scott Teel <[email protected]>
Reviewed-by: Kevin Barnett <[email protected]>
Signed-off-by: Don Brace <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

0 files changed, 0 insertions, 0 deletions