scsi: core: Only re-run queue in scsi_end_request() if device queue is busy

The request queue is currently run unconditionally in scsi_end_request() if
both target queue and host queue are ready.

Recently Long Li reported that cost of a queue run can be very heavy in
case of high queue depth. Improve this situation by only running the
request queue when this LUN is busy.

Link: https://lore.kernel.org/r/[email protected]
Reported-by: Long Li <[email protected]>
Tested-by: Long Li <[email protected]>
Tested-by: Kashyap Desai <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Ewan D. Milne <[email protected]>
Reviewed-by: John Garry <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

0 files changed, 0 insertions, 0 deletions