Hi, I need to use Open MPI to distribute 2d-array in the PGM file among 10 working computers. Then I need to manipulate each value of the array to get a negative image (255-i) and then print the output back. I'm thinking of using mpi_scatterv and mpi_gatherv to distribute the data. After i compile the program, it got segmentation faults. I dont know what is the problem whether my code wrong or compiler. I integrate the code to read/write pgm from pgm_RW_1.c and the MPI code in exmpi_2.c.
--I install OPEN MPI version 1.4.1-2 via Synaptic Package Manager on UBUNTU 10.04. --I compile with : mpicc -o exmpi_2 exmpi_2.c --I run for testing (segmentation faults): mpirun -np 10 ./exmpi_2 2.pgm out.pgm --Then I run with hostfile: mpirun -np 10 --hostfile .mpi_hostfile ./exmpi_2 2.pgm out.pgm Here is the error: ____________________________________________________________________________ arep@ubuntu:~/Desktop/fyp$ mpirun -np 10 ./exmpi_2 2.pgm out.pgm [ubuntu:02948] *** Process received signal *** [ubuntu:02948] Signal: Segmentation fault (11) [ubuntu:02948] Signal code: Address not mapped (1) [ubuntu:02948] Failing at address: (nil) [ubuntu:02948] [ 0] [0x792410] [ubuntu:02948] [ 1] ./exmpi_2(main+0x1f6) [0x8048d2a] [ubuntu:02948] [ 2] /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6) [0x126bd6] [ubuntu:02948] [ 3] ./exmpi_2() [0x8048aa1] [ubuntu:02948] *** End of error message *** -------------------------------------------------------------------------- mpirun noticed that process rank 0 with PID 2948 on node ubuntu exited on signal 11 (Segmentation fault). -------------------------------------------------------------------------- ____________________________________________________________________________ Here is the input 2.pgm image : http://orion.math.iastate.edu/burkardt/data/pgm/balloons.pgm TQ for your help.
pgmmpi.tar.gz
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