Thanks. I said "jobstep task" -- I was thinking of a batch job.

Right, the ATTACH(X) doc is fairly clear on the relationship of subtasks to
the mother task.

So this is inherent in the guts of MVS -- not something in PROGxx or
somewhere like that?

Charles

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On
Behalf Of Greg Dyck
Sent: Thursday, May 26, 2016 3:11 PM
To: [email protected]
Subject: Re: Questions on DPMOD

On 5/26/2016 2:51 PM, Charles Mills wrote:
> 1. Where is the original dispatching and limit priority for the 
> jobstep task set? How do I determine (not with an API at runtime, but 
> in advance with a command or looking at a parm member) what it is
presumably going to be?
>

Sigh... the initial starting value varies by who attaches the jobstep task.
And then any subsequent attaches in the task tree effect the value for the
attached task.

The thing to remember is that the (task) minor priority is a tie-breaker
between work (tasks and preemptable SRBs) running within a single address
space.  Between the work for two different address spaces it is irrelevant.

It's been over 20 years since I had to deal with problems in this area
(MVS/ESA SP5.1), and I don't remember all the specifics.  I know that
jobsteps attached by the started task controller start with a minor priority
of 255.  I think the same is true of batch initiator jobs.  I believe the
TSO TMP attaches all commands with a minor priority of 250. 
And UNIX Systems Services did not exist at the time.

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