Hi Sven,

thanks for the details!

Best, Julien

On 29/03/2019 17:21, Sven Hansen wrote:

Hi Julien,

SLURM will attempt sane binding under the premise that you give it the right information in your batch script. The reason it does not behave like you expect it to is the virtual sub-NUMA clustering of the Skylake CPUs which splits a single die(/socket) into two distinct NUMA nodes. Thus, you can even ask for

#SBATCH -B 4:12[:1]

without any problem but as soon as you try to request more than 12 cores per (virtual) socket - or more than 4 sockets for that matter -, SLURM will reject the request.

Best, Sven

On 3/29/19 4:40 PM, Julien Guénolé wrote:

...

Hi all,

is the binding to cores automatic with SLURM?

The command --cpu-bind=cores is not recognized.

I tried to force the binding by using #SBATCH -B 2:24:1 but it says that there is no such nodes available. However #SBATCH -B 2:12:1 works unexpectedly fine!

Thanks!

Bests, Julien