jmartin wrote:
> Hi,
>
> I have checked the WLM documentation and it seems that you can limit
> the percentage of CPU that an application or user can use, but not the
> number of processors that it can use. I have 3 processors but
> specifying 66% or CPU usage doesn't assure that you are using 2
> processors, I think.
>
> Is there a way to limit the processors an application can use?
>
> There is an application: LoadLeveler, anybody knows if it can be
> configured to limit the number of processors an application or user can
> use?
>
> Thanks in advance,
>
> Hajo Ehlers ha escrito:
>
> > jmartin schrieb:
> >
> > > Hi,
> > >
> > > I am working on a AIX 5 system with three processors and we would like
> > > to limit the maximum number of processors a multithread application is
> > > allowed to use to two.
> > >
> > > Is this possible at application level, or is it possible at user level
> > > to limit the number of processors that the application or user is going
> > > to use.
> >
> > man wlm ( Work Load Manager )
> >
> > The wsm has a nice interface for the work load manager ( wlm )
> >
> > hth
> > Hajo

Hi,

Depending on the AIX version and hardware you can disable a processor
completely.

Use the following procedure:

WARNING! The CPU can only be reenabled by rebooting!

List available processors:

$ bindprocessor -q
The available processors are: 0 1 2 3 4 5

Then use cpu_deallocate to switch one off:
cpu_deallocate requires a logical CPU number
Usage: cpu_deallocate logical_CPU_id [-P]

$ cpu_deallocate 5

Then enter the following:

$ chdev -a cpuguard=enable -l sys0
sys0 changed

And now list processors again:

$ bindprocessor -q
The available processors are: 0 1 2 3 4


I don't know what the -P flag does, so I suggest not using it (because
perhaps it means 'permanent'?)!!

Scott