Sounds interesting ! Regarding my bug report, I don't think it is very important.
Here's why: According to the standard MPI 2.2, Open-MPI is correct when blocking on any MPI_Send. So, even if Open-MPI __should__ (according to its documentation) send messages of 4096 bytes or less eagerly (with shared memory), the opposite is compliant too. What I have learn is that my program should be designed and implemented according to MPI 2.2, not Open-MPI 1.4.3 or another implementation. On Sat, 2010-11-20 at 11:14 -0500, Christopher Samuel wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hi folks, > > At SC10 this year there was an interesting tool presented > as a student paper called "FlowChecker: Detecting Bugs in > MPI Libraries via Message Flow Checking". > > http://sc10.supercomputing.org/schedule/event_detail.php?evid=pap352 > > Basically they instrument a program and derive "intentions" > from your MPI calls and the MPI standard and also trace the > data flow (including things like memcpy) and messages.Then > offline you run a correlator which compares what was meant > to happen and what did and tries to root cause the fault. > > They claim to have taken 5 random closed bugs from 3 different > MPI implementations (including 3 from Open-MPI) and been able > to detect all 5 and root-cause 4 of them (the one they missed > was a data type issue). > > The PDF of their paper is here: > > http://www.cse.ohio-state.edu/~chenzhe/sc10-flowchecker.pdf > > I've emailed them to see if the code is going to be available > as it could be quite a handy tool to have when trying to track > down issues like the one Sébastien posted about. > > cheers, > Chris > - -- > Christopher Samuel - Senior Systems Administrator > VLSCI - Victorian Life Sciences Computational Initiative > Email: sam...@unimelb.edu.au Phone: +61 (0)3 903 55545 > http://www.vlsci.unimelb.edu.au/ > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.10 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iEYEARECAAYFAkzn884ACgkQO2KABBYQAh+jAQCggP+izYq3rkSo1hPzADi2vCEI > z2QAmwX5oEYpgYYlc6ZWC3Pr3q1dBGp/ > =2KB+ > -----END PGP SIGNATURE----- > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel
