I notice Absoft's MTT runs are failing due to the change in bind-to-core-by-default:
http://mtt.open-mpi.org/index.php?do_redir=2136 I asked Tony, who runs the Absoft MTT runs; he confirms that this particular machine has 1 socket with 2 cores (and we're running -np 4 on this machine). 1. This is an unintended consequence of the bind-to-core-by-default policy: we fail with "oversubscribed!" when running on a single machine for test runs like this. Do we like this? See #3, below, for more on this. 2. Also, the error message that is displayed says: ----- A request was made to bind to that would result in binding more processes than cpus on a resource: Bind to: CORE Node: ltljoe3 #processes: 2 #cpus: 1 ----- Which is odd, because the command line is "mpirun -np 4 --mca btl sm,tcp,self ./c_hello". Any idea what's happening here? 3. Finally, we're giving a warning saying: ----- WARNING: a request was made to bind a process. While the system supports binding the process itself, at least one node does NOT support binding memory to the process location. ----- For both #1 and #3, I wonder if we shouldn't be warning if no binding was explicitly stated (i.e., we're just using the defaults). Specifically, if no binding is specified: - if we oversubscribe, (possibly) warn about the performance loss of oversubscription, and don't bind - don't warn about lack of memory binding Thoughts? -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
