[Documentation] Explain calling of external executables in more detail #733
Description
It is important to use srun or flux run when calling external executables from Python functions submitted to executorlib. Still unless nested executors are used, these jobs appear as additional tasks in the list of tasks from the queuing system. This should be explained in more detail, for example by extending the following sections:
- https://executorlib.readthedocs.io/en/latest/5-2-quantum-espresso.html
- https://executorlib.readthedocs.io/en/latest/3-hpc-job.html#nested-executors
This becomes even more important when calling GPU applications like nvidia-smi, without flux run or srun these applications have access to all GPUs of a given compute node. This can result in unintended resource sharing and slower performance. In the same way the relation to block_allocation=True should be explained in more detail.