MVS/370 also used absolute zero for the IPL processor.
In MVS/XA, we changed to use a non-zero prefix for every processor.
Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp.
Poughkeepsie NY
"IBM Mainframe Assembler List" wrote on
11/12/2019 01:51:22 PM:
> From: "Seymour J
From memories of 30-ish years ago...
I worked on MDF (Multiple Domain Facility -- What IBM came to
call PR/SM and domains got called LPARs) at Amdahl.
So let me elaborate on what Seymour said just based on the Amdahl
MVS Structure and Flow class I had (2 weeks of in depth teaching).
When
No, it's not a waste of resources. There is a valid use case regardless of
whether you can conceive of it.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From: IBM Mainframe Assembler List on behalf
of John McKown
Sent: Tuesday, November
I don't know about MVS, but OS/360 support for 65MP used absolute address 0 for
one processor.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From: IBM Mainframe Assembler List on behalf
of John McKown
Sent: Tuesday, November 12, 2019 9:49
I believe that z/OS creates a PSA virtual address for every processor. As you
guessed, absolute address zero is defined in the context of the LPAR or virtual
machine, not the bare metal.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
From:
I had a reason a couple weeks ago. We were trying to programmatically
verify whether we were running certain code on a zIIP or a CP. I found
a bit in the PSA that it appeared was set if you're on a zIIP and not if
not. It was not set for my PSA, (not surprising since I was on TSO ISPF
running
On Tue, 12 Nov 2019 08:49:36 -0600, John McKown wrote:
> I have never wanted to look at the PSA of any CP other than the
>one that I am running on. I'm not really sure why I would. Do you know of a
>reason to do so? I am curious.
I have no need to do so, and don't know why I might. But the post
On Tue, Nov 12, 2019 at 8:43 AM Tom Marchant <
00a69b48f3bb-dmarc-requ...@listserv.uga.edu> wrote:
> >I cannot fathom the reason to use _any_ base for the PSA other than GPR0.
> >It is simply wasteful of a scarce resource.
>
> It isn't "the" PSA. There is the PSA of the processor that you are
The question is what reasonable use is there is of USING on a number?
I'm not sure what the rest of this post means, but it doesn't seem relevant.
sas
On Mon, Nov 11, 2019 at 2:35 PM Paul Gilmartin <
0014e0e4a59b-dmarc-requ...@listserv.uga.edu> wrote:
> On 2019-11-11, at 09:08:39, Steve
On Tue, 12 Nov 2019 07:13:16 -0600, John McKown wrote:
>On Tue, Nov 12, 2019 at 6:56 AM Peter Relson wrote:
>
>>
>> What if R9 is not supposed to be zero? Maybe the code is looking at the
>> PSA
>> of another processor.
>>
>>
>> The normal way to accomplish that is
>> USING PSA,R9
>>
On Tue, Nov 12, 2019 at 6:56 AM Peter Relson wrote:
>
> What if R9 is not supposed to be zero? Maybe the code is looking at the
> PSA
> of another processor.
>
>
> The normal way to accomplish that is
> USING PSA,R9
> rather than leaving a time-bomb for those who come after by using
What if R9 is not supposed to be zero? Maybe the code is looking at the
PSA
of another processor.
The normal way to accomplish that is
USING PSA,R9
rather than leaving a time-bomb for those who come after by using "0".
Peter Relson
z/OS Core Technology Design
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