topic Re: Turn OFF CPU Affinity on Itanium OVMS 8.2 in Operating System - OpenVMS

Turn OFF CPU Affinity on Itanium OVMS 8.2

Paul Goslin — Wed, 10 Dec 2008 15:02:33 GMT

Programmer has requested I turn off CPU affinity , they wrote:
working with a customer on a problem and need to test on ARCHER with the affinity off.

CPU 0 has affinity set in the bindings:

Bindings:
DECW$SERVER_0 PID = 00001036 Reason: Affinitized to this CPU
----------------------------
How do I turn this OFF ? or even see it ?

Re: Turn OFF CPU Affinity on Itanium OVMS 8.2

Robert Gezelter — Wed, 10 Dec 2008 15:14:16 GMT

Paul,

Check the HELP text for SET PROCESS/AFFINITY. The correct online documentation can be found in the DCL Dictionary (currently, the SET PROCESS command can be found at http://h71000.www7.hp.com/doc/83final/9996/9996pro_209.html#brass_78 ) on the OpenVMS www site at http://www.hp.com/go/openvms .

A cautionary note is in order to also check the DECwindows documentation to see the precise reason it has affinity set to CPU 0.

- Bob Gezelter, http://www.rlgsc.com

Re: Turn OFF CPU Affinity on Itanium OVMS 8.2

Hoff — Wed, 10 Dec 2008 15:24:22 GMT

Do ask your programmer what is needed when presented with this. As a rule, we're further removed from the intended request than you are.

Closing the loop with the programmer making the request is usually faster than using ITRC, as you'll now have to back-determine if I've given the right answer for the particular context.

The basic command for scheduling-level affinity (there are a couple of confusingly-named constructs here that share the "affinity" naming) is built on the command:

SET PROCESS /[NO]AFFINITY/PERMANENT

What you're showing is a cut-down version of the output from the command:

SHOW CPU/FULL 0

where the parameter s the CPU number.

Check the HELP libraries and the OpenVMS manuals and Google for some additional details on these commands, and on scheduling-level affinity.

I'd probably poke around the system startup files looking for "AFFINITY" and such, and would discuss what's going on here with the programmer. As was mentioned.

Re: Turn OFF CPU Affinity on Itanium OVMS 8.2

Volker Halle — Thu, 11 Dec 2008 13:45:52 GMT

Paul,

to turn off affinity of the DECW$SERVER_0 process to CPU 0, you could use the following command (based on your SHOW CPU/FULL output):

$ SET PROC/AFF/PERM/ID=00001036/CLEAR=0

Volker.

Re: Turn OFF CPU Affinity on Itanium OVMS 8.2

Paul Goslin — Fri, 12 Dec 2008 12:30:53 GMT

Thank you all for your suggestions, tips... etc...

We have resolved this issue for now.