#1850: Severe performance problem on Stampede -------------------------+-------------------------------------------------- Reporter: hinder | Owner: Type: defect | Status: confirmed Priority: major | Milestone: Component: SimFactory | Version: development version Resolution: | Keywords: -------------------------+--------------------------------------------------
Comment (by eschnett):
SystemTopology's default behaviour is harmful if you run multiple independent simulations on the same node, e.g. if you are using a personal workstation. In this case, the two SystemTopology instances don't know about each other, and will both choose the same cores, reducing performance by 1/2. There is no good way around this -- if a simulation doesn't "own" a node, then something else with more knowledge (e.g. the kernel) needs to schedule thread/core assignments.
Otherwise, SystemTopology should always be beneficial, or at least not harmful.