On Mon, Apr 2, 2012 at 8:57 PM, Barry Smith <bsmith@mcs.anl.gov> wrote:

On Apr 2, 2012, at 8:10 PM, Tabrez Ali wrote:

> Hello
>
> I am trying to debug a program using the switch '-on_error_attach_debugger' but  the vendor/sysadmin built PETSc 3.2.00 is unable to start the debugger in xterm (see text below). But xterm is installed. What am I doing wrong?
>
> Btw the segfault happens during a call to MatMult but only with vendor/sysadmin supplied PETSc 3.2 with PGI and Intel compilers only and _not_ with CRAY or GNU compilers.

  My advice, blow off "the vendor/sysadmin supplied PETSc 3.2" and just built it yourself so you can get real work done instead of trying to debug their mess.   I promise the vendor one is not like a billion times faster or anything.

If you want to justify this to anyone (like a funder), just run both on ex5 for a large size and look at the flops on MatMult. That

is probably your dominant cost (or your PC).

   Matt

 

  Barry

>
> I also dont get the segfault if I build PETSc 3.2-p7 myself with PGI/Intel compilers.
>
> Any ideas on how to diagnose the problem? Unfortunately I cannot seem to run valgrind on this particular machine.
>
> Thanks in advance.
>
> Tabrez
>
> ---
>
> stali@krakenpf1:~/meshes> which xterm
> /usr/bin/xterm
> stali@krakenpf1:~/meshes> aprun -n 1 ./defmod -f 2d_point_load_dyn_abc.inp -on_error_attach_debugger
> ...
> ...
> ...
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range
> [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/faq.html#valgrind[0]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X to find memory corruption errors
> [0]PETSC ERROR: configure using --with-debugging=yes, recompile, link, and run
> [0]PETSC ERROR: to get more information on the crash.
> [0]PETSC ERROR: User provided function() line 0 in unknown directory unknown file
> [0]PETSC ERROR: PETSC: Attaching gdb to ./defmod of pid 32384 on display localhost:20.0 on machine nid10649
> Unable to start debugger in xterm: No such file or directory
> aborting job:
> application called MPI_Abort(MPI_COMM_WORLD, 0) - process 0
> _pmii_daemon(SIGCHLD): [NID 10649] [c23-3c0s6n1] [Mon Apr  2 13:06:48 2012] PE 0 exit signal Aborted
> Application 133198 exit codes: 134
> Application 133198 resources: utime ~1s, stime ~0s

--
What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
-- Norbert Wiener