[petsc-users] If valgrind says no memory prolbem.

[Aron Ahmadia]

A SEGV is definitely a memory access problem, as PETSc suggests, it is
likely to be a memory access out of range.

I don't recommend trying to debug this problem on amdahl, can you reproduce
the problem just running with multiple processes on your workstation?

Warm Regards,
Aron

On Wed, Apr 21, 2010 at 12:34 PM, (Rebecca) Xuefei YUAN <xy2102 at columbia.edu
> wrote:

> Dear all,
>
> I checked the code with valgrind, and there is no memory problem, but when
> running parallelly, there is a message like
>
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
> probably memory access out of range
> srun: error: task 0: Exited with exit code 59
> [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [0]PETSC ERROR: or see
> http://www.mcs.anl.gov/petsc/petsc-as/documentation/troubleshooting.html#Signal[0]PETSCERROR: or try
> http://valgrind.org on linux or man libgmalloc on Apple to find memory
> corruption errors
> [0]PETSC ERROR: likely location of problem given in stack below
> [0]PETSC ERROR: ---------------------  Stack Frames
> ------------------------------------
> [0]PETSC ERROR: Note: The EXACT line numbers in the stack are not
> available,
> [0]PETSC ERROR:       INSTEAD the line number of the start of the function
> [0]PETSC ERROR:       is given.
> [0]PETSC ERROR: --------------------- Error Message
> ------------------------------------
> [0]PETSC ERROR: Signal received!
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: Petsc Release Version 3.0.0, Patch 7, Mon Jul  6 11:33:34
> CDT 2009
> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
> [0]PETSC ERROR: See docs/index.html for manual pages.
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: /tmp/lustre/home/xy2102/April2110/die0/./twqt2ff.exe on a
> linux-c-g named sci-m0n0.scsystem by xy2102 Wed Apr 21 05:30:10 2010
> [0]PETSC ERROR: Libraries linked from
> /home/xy2102/soft/petsc-3.0.0-p7/linux-c-gnu-debug/lib
> [0]PETSC ERROR: Configure run at Mon Jul 20 13:56:37 2009
> [0]PETSC ERROR: Configure options --with-cc=mpicc --with-fc=mpif77
> --with-mpiexec=srun --with-debugging=1 --with-fortran-kernels=generic
> --with-shared=0 --CFLAGS=-G0 --FFLAGS=-G0
> [0]PETSC ERROR:
> ------------------------------------------------------------------------
> [0]PETSC ERROR: User provided function() line 0 in unknown directory
> unknown file
> application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0
> In: PMI_Abort(59, application called MPI_Abort(MPI_COMM_WORLD, 59) -
> process 0)
> srun: error: task 2-3: Killed
> srun: error: task 1: Killed
>
> What is wrong?
>
> Cheers,
>
> Rebecca
>
> --
> (Rebecca) Xuefei YUAN
> Department of Applied Physics and Applied Mathematics
> Columbia University
> Tel:917-399-8032
> www.columbia.edu/~xy2102
>
>
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