#921: Automatic undersubscribing --------------------------+------------------------------------------------- Reporter: hinder | Owner: eschnett Type: enhancement | Status: new Priority: minor | Milestone: Component: SimFactory | Version: Resolution: | Keywords: --------------------------+-------------------------------------------------
Comment (by eschnett):
The current behaviour does not assume that you are running on only a single node. It works as follows: - user requests N cores (via --procs) - system granularity is determined (e.g. can allocate only integer number of nodes) (depends on --ppn-used) - if necessary, N is rounded up
What you suggest is to modify the value specified via --ppn-used instead of the value specified via --procs. Or are you suggesting to do this only if at most a single node is allocated? Or do you suggest to not round up at all, and leave some cores unused?
The intention behind rounding up is that you will have to pay for these cores anyway, so you may as well use them. Whether this is correct very likely doesn't depend on the PPN of the system you use. In a production run, you probably want to use the additional cores (why not?), in a benchmark you don't. But then, in a benchmark you probably need to be aware of the node configuration anyway, so you may as well specify --ppn- used.