[torqueusers] altix cpu set support
brockp at umich.edu
Fri Jan 26 09:57:54 MST 2007
On Jan 26, 2007, at 11:01 AM, Malcolm Tobias wrote:
> On Friday 26 January 2007 09:06, you wrote:
>> Any tips would be helpful! Or insight into the benefits of
>> cpusets. I understand the thory. But I so far see no difference.
>> (manually setting with dplace)
> Greetings. I've been running an Altix for years, but went with
> PBSPro because
> at the time it was the only queuing system that supported cpusets.
Yeah we are aware that pbsPro supports it, I found some posts about
work going into torque which we use on all our clusters.
> When you see no difference using cpusets, you mean there's no
> difference between running with cpusets and without?
Yes our test is a collection of codes, the system we are evaluating
has 16 useable cores, For example if i run a 8 cpu without placement
(no dplace) vs with dplace i see no runtime change over the few
hour long run. I will try and force the system to push processes
around. But so far i have not seen a difference,
> You'll only see
> performance hits if the OS migrates one of the processes from one
> CPU to
> another. The cost of doing this also depends on how much memory
> each process
> is using.
One test was a abaqus model, it was using 24GB of ram (system is
equipped with 64GB) Even when using /dev/shm as scratch (another
20GB total 44 GB ram used) I see no change.
> Malcolm Tobias
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