how to set a processor

[Wahyono_1]

i have two processors running in an alpha server. both are running but i cannot assign one of the processor to a processor set.
so if we check with 'pset_info', only one processor is running. what are the ways to set these processors.

[Ravi_8]

Hi,

Look into man pages of 'psradmin' or 'psradm'. It explains well

[Michael Schulte zur Sur]

Hi,
you can do it in this sequence:
pset_create
pset_assign_cpu 2 1
2 is the new processor set, 1 the cpu you assign to it.

greetings,

Michael

[Hein van den Heuvel]

>> i cannot assign one of the processor to a processor set.


Why not? Do you not know how to do it, or does it give an error? Which commands used?
What does 'pset_info -v' show?

More importantly... what real problem are you trying to solve.
I suspect that dividing a 2-cpu box into 2-psets makes it inflexible and poorly performaning for some tasks.
That would be because psets are exclusive, non-overlapping.

You may want to consider runon to force a select process/command on a selected processor. Maybe toss some renice (nasty) in the mix to enforce near exclusive usage... if the process needs it. This will hopefully reduce context switches just about as much, and give you some extra performance through affinity while keeping the system flexible to do say backups without having to change those psets again.

hth,
Hein.

[Ross Minkov]

I second the previous post.

Also check cpu_mask (or something like that) SRM variable at the >>> prompt. Make sure it enables all the CPUs.

Regards,
Ross

[Wahyono_1]

Hi all,

thanks for your help.
i have tried some of your suggestions.
if i use 'assign_cpu_to_pset', nothing happens.
if i use 'psradm', it says 'permission denied (login using root).
i haven't tried other options, cause it's in the running system...i have to consider the impact

[Michael Schulte zur Sur]

Hi,

have you done it in the sequence I posted?
Can you post pset_info?

thanks,

Michael

[Wahyono_1]

Dear Michael,

yes i have already tried that.
it says 'too many processors requested'

rgrds
wahyono

[Michael Schulte zur Sur]

Hi,

please post the pset_info output. I suspect as Ross that you are not running all cpus. Does monitor show all cpus?

greetings,

Michael

[Ross Minkov]

You don't need to shutdown the system to check the value of a SRN variable. Do this from the OS:

/sbin/consvar -g cpu_enabled

Let us know what the value was.

Regards,
Ross