Hi Gilbert, Checksums are turned off by default. If you need checksums to be activated add "-mca pml csum" to the mpirun command line. Checksums are enabled only for inter-node communication. Intra-node communication is typically over shared memory and hence checksum is disabled for this case. If you have built a debug version of Open MPI (--enable-debug), you can see the checksum output by appending "-mca pml_base_verbose 5" to your command line. If you are interested in the relevant code it is located here - ompi/mca/pml/csum
--Nysal On Tue, Aug 31, 2010 at 1:22 PM, Gilbert Grosdidier <gro...@mail.cern.ch>wrote: > Bonjour, >> >> I'm not sure I understand how to trigger CHECKSUM use >> inside of OpenMPI 1.4.1 (after digging in the FAQs, I got not >> explanations, sorry): >> >> - Is checksuming activated by default and embedded automatically >> within the Send/Recv pair mechanism, please ? >> - If not, which MCA param(S) should I set to activate it ? >> - Is there a time penalty for using it, please ? >> >> Thanks in advance for any help. >> >> -- >> Regards, Gilbert. >> >> >> > -- > *---------------------------------------------------------------------* > Gilbert Grosdidier gilbert.grosdid...@in2p3.fr > LAL / IN2P3 / CNRS Phone : +33 1 6446 8909 > Facult??des Sciences, Bat. 200 Fax : +33 1 6446 8546 > B.P. 34, F-91898 Orsay Cedex (FRANCE) > --------------------------------------------------------------------- > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
