From: Paul H. Hargrove (PHHargrove_at_lbl_dot_gov)
Date: Tue Jun 09 2009 - 12:25:04 PDT
Gabriele, We do not have direct control of process/thread pinning via upcrun. In particular the only placement-related arguments we pass to aprun are -n and -N. However, on the Cray XT one can launch Berkeley UPC applications directly with aprun, for instance to use the -S and -d options. The only thing to keep in mind if one does so is that many of the options to upcrun operate by setting environment variables. So, if you use any non-default options to upcrun you should run 'upcrun -show <your args>' and look for lines beginning with "*** upcrun setting:", to find the env vars that are being used (you can safely ignore UPC_NODES and GASNET_SSH_SERVERS, which don't affect anything on the Cray XT). Let us know if you need more information. -Paul Gabriele Jost wrote: > Hello! > > Does upcrun support placing threads/processing on different sockets of a multi-core node? Like, on a Cray XT5 (just as an example), I can specify "aprun -S 1" to ensure that 1 MPI process is placed on each socket. I know about "upcrun -c 2" to use only 2 cores, but I guess this does not mean 1 core on each socket. > > Thanks in advance, > Gabriele > > -- Paul H. Hargrove PHHargrove_at_lbl_dot_gov Future Technologies Group Tel: +1-510-495-2352 HPC Research Department Fax: +1-510-486-6900 Lawrence Berkeley National Laboratory