The processors and processors_per_node Settings in the Hosts File

For hosts with multiple processors that are not running a queueing system, set processors to the number of processors on the host. For batch queues, set processors to the number of processors available to the queue.

Here, “processors” refers to hardware units capable of running a job, which for most recent hardware means “cores”.

For applications (such as Jaguar) that use OpenMP for threaded parallel execution, set processors_per_node to the number of processors available on each node available to a batch queue. You should ensure that the host for the queue does not have nodes with different numbers of processors.

Within the qargs setting, you can use %PPN% as a variable that has the value of the processors_per_node setting, and %NPROC/PPN% for the number of nodes (total number of processors divided by the number of processors per node).