On Fri, Oct 13, 2017 at 04:31:04PM +0000, Bart Van Assche wrote:

On Sat, 2017-10-14 at 00:07 +0800, Ming Lei wrote:

quoted

Actually it is in hot path, for example, lpfc and qla2xx's queue depth is 3,

Sorry but I doubt whether that is correct. More in general, I don't know any modern
storage HBA for which the default queue depth is so low.

You can grep:

[ming@ming linux]$ git grep -n cmd_per_lun ./drivers/scsi/ | grep -E "qla2xxx|lpfc"

Even SRP/IB isn't big too, just 32.

-- 
Ming