On Thursday, 21 February 2019 1:00:52 PM PST Sam Hawarden wrote: > Linux assigns numbers to your CPUs. 0-15 will be socket 1, thread 1. 16-31 > are socket 2, thread 1, 32-47 are socket 1, thread 2. 48-63 are socket 2, > thread 2.
This isn't strictly true, for x86 for instance the kernel will read firmware tables to discover how the vendor has assigned the core numbering. This means it can vary from vendor to vendor and model to model plus it can potentially change on a firmware upgrade, just to make life even more exciting. This is why hwloc (and its predecessors) exist, to give a sane interface and default logical layout. Slurm uses a similar system that results in something that looks very similar, so to Slurm CPU 0 is socket 1, core 1, thread 1 and CPU 2 is socket 1, core 1, thread 2, etc... All the best, Chris -- Chris Samuel : http://www.csamuel.org/ : Berkeley, CA, USA