[lug] Processor assignment

[Zan Lynx]

On 3/30/2016 3:49 PM, Rob Nagler wrote:
> We are using OpenMPI to distribute a job across many cores, but the 
> kernel isn't cooperating. It overloads cores when there are many 
> available cores. At first, we thought this only showed up in Docker 
> containers, but we've been able to reproduce it natively both on 
> CentOS 6 and Fedora 23 and with Docker on CentOS 6, Fedora 23, and 
> Debian Jessie.
>
> A simple example program along with a short description can be found 
> here: https://github.com/robnagler/mpi-play/issues/1  On a 2 x 
> E5-2699-v3 node running Debian, we're seeing proper allocation 
> natively but in the container, the allocation is "incorrect".
>
I find your description a little confusion, because you say you were 
able to reproduce it natively but you also say it only happens inside 
containers.

To be sure, you aren't doing anything with resource limits, are you? 
This link includes the things you can do. And if you're running 
Kubernetes, these will happen automatically.
https://docs.docker.com/engine/reference/run/#runtime-constraints-on-resources

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