#774: hack to unfix OpenMP threads from cores on Cray machines -----------------------+---------------------------------------------------- Reporter: rhaas | Owner: eschnett Type: task | Status: closed Priority: optional | Milestone: Component: Carpet | Version: Resolution: fixed | Keywords: hack -----------------------+----------------------------------------------------
Comment (by rhaas):
The current implementation in Carpet will warn (I believe) on Kraken even when everything is ok since the run was started with aprun -cc numa_mode. In that case, 6 threads are bound to cores 0-5 and 6 threads are bound to cores 7-11 (ie half to one socket half to the other) presumably to avoid having to access memory belonging to the "other" socket.
Since Carpet checks (on a single root thread only) that the number of cores on which this thread might run is at least as large as the number of threads requested, the test fails (since any given thread is only allowed to run on half the cores).