Re: Task Sets in SCSI and Linux

James Bottomley
2002-05-08T16:34:45Z

mheinz@infiniconsys.com said:
> From perusing the source code it appears to me that the Linux SCSI
> layers do not take advantage of SCSI task sets. Is that correct?

Could you elaborate on what you mean by "task set"? SCSI 3 defines a task
simply as "work to be performed by the logical unit in the form of a command
or a group of linked commands". This basically means the I_T_L or I_T_L_Q
nexus of scsi2, however scsi3 expands this for multi-ported devices. "task
set" usually just means the outstanding tasks on a given logical unit, and as
such it's really a target concept although the initiator must know how to
track outstanding tasks correctly.

If by "take advantage of SCSI task sets" you mean use tagged tasks to get
multiple outstanding tasks on a logical unit, the answer is yes but it depends
on the low level driver implementation.

James Bottomley