On Tue, 1 Oct 2002, khoa nguyen wrote: > I've run a couple of applications with LAM, and it keeps giving me the > error message like : > > MPI process rank 1 (n2, p20124) caught a SIGSEGV in MPI_Isend. > Rank (1, MPI_COMM_WORLD): Call stack within LAM: > Rank (1, MPI_COMM_WORLD): - MPI_Isend() > Rank (1, MPI_COMM_WORLD): - main() > > Anyone has experienced this kind of error like this before?
These errors are pretty common in MPI programs - they are usually the result of "memory badness", meaning that some memory LAM maintains in your process space got scribbled on by the application. And it all goes down hill from there :). The other common problem is improper arguments to the MPI call. One thing that commonly causes problems is the length field, which is number of datatypes, not the number of bytes (unless the datatype is MPI_BYTE), or if you are using FORTRAN, forgetting to add the last argument can cause segfaults. Without seeing your code, I can't really point you to the exact problem. However, a memory checking debugger (or even using the debug flags in GNU's malloc - man malloc for more information) can be useful. Can you run any MPI applications? For example, if you download the LAM testsuite off of the LAM web page (http://www.lam-mpi.org/download/), does it run to completion? > Since I wonder whether or not the LAM environment has been setting up > corresponding w/ my system, and I'm thinking of re-install the LAM > packages. If that is the case, which directory should I re-run the LAM > tar bar sothat it won't create any problems w/ the rest of packages in > OSCAR. Also, once I run the script LAM , configure, would it over-write > all configurations that have been setted by the LAM that is going along > w/ OSCAR ? In other words, are there any case could I have co-exist 2 > LAMs (one by OSCAR, and one by my own). I'm using oscar1.2.1rh72. I would recommend against trying to update LAM yourself. You don't gain any functionality and getting everything "just right" is a pain. As I stated before, I would guess your problems are somewhere beside the LAM install. Brian -- Brian Barrett LAM/MPI developer and all around nice guy Have a LAM/MPI day: http://www.lam-mpi.org/ ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ Oscar-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/oscar-users
