More: SAM-5 Command Timeout Subproposal for 14-107

Paul Suhler Paul.Suhler at hgst.com
Thu May 29 09:30:50 PDT 2014


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Okay, that attempt to provoke the lions' den did not evoke any roars, so it
must have been acceptable, n'est pas?  So, here's another try:
The previously-posted revision specified when a command timeout occurs.  I
now propose to implement the timeout into the state machines by stating that
when a timeout occurs, the device server sends a (newly-defined) Time Out
Command message to the appropriate set of LU_CS states.  And I'll define the
resulting behaviors.
Thanks,
Paul
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Paul Suhler
Sent: Wednesday, May 28, 2014 4:01 PM
To: T10 E-mail Reflector (t10 at t10.org)
Subject: SAM-5 Command Timeout Subproposal for 14-107
Hi, George (and anyone else who wishes to comment).
As suggested in CAP in May, I'm trying to leverage the new state machines in
14-054 for defining the command deadline operations.  For example, in order
to record the arrival time of a command and set its expiration time, I want
to abandon adding an argument to the Route Command operation and instead hang
it on a newly-defined transition.  Using 14-054r3 as a base, I propose to add
the paragraph in blue:
8.9.4.2 LU_CS1:Idle state
8.9.4.2.1 LU_CS1:Idle state description
This is the initial state of the LU_CS state machine.
8.9.4.2.2 Transition LU_CS1:Idle to LU_CS2:Dormant
This transition shall occur after receiving:
a) a Queue Command message with a Task Attribute argument set to Simple; or
b) a Queue Command message with a Task Attribute argument set to Ordered.
This transition shall include the following arguments:
a) I_T_L_Q Nexus;
b) CDB;
c) Task Attribute;
d) CRN, if any;
e) Command Priority, if any; and
f) First Burst Enabled, if any.
If this transition occurred after receiving a Queue Command message with a
Task Attribute set to simple, then the Deadline Expiration time attribute of
this command shall be set as specified in 8.7.2.2.
The new subclause 8.7.2.2 relies upon the proposed command deadline clock,
which is in the logical unit, and upon a command deadline value in the
proposed Command Deadline mode page.
Any problems with specifying this behavior here?  Other questions?
Thanks,
Paul
Paul A. Suhler, PhD
Research Staff Member
HGST Research
paul.suhler at hgst.com
o: 949-476-1180 x275448
m: 949-241-6443
3001 Daimler St.
Santa Ana, CA 92705-5812
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