[Darshan-users] Segmentation fault with Darshan-3.1.1

[Phil Carns]

Hi Preeti,

Kevin is right; it is preferable to just set LD_PRELOAD for the 
application that you want to instrument.

That said, LD_PRELOAD of Darshan on normal command line programs isn't 
supposed to cause a segmentation fault.  In principle it should just 
silently do nothing if MPI isn't initialized in the executable in 
question.  There can be a number of complicating factors, though.  If 
you can't avoid the problem then let us know (maybe with a stack trace 
from the core file) and we can try to debug it further.

thanks,
-Phil

On 10/24/2016 05:08 PM, Harms, Kevin wrote:
>    If you set LD_PRELOAD in your shell, then you will be intercepting any POSIX operations by any program, such as ls. I’m guessing you don’t want to profile ‘ls’? You can set LD_PRELOAD only for the application you want to profile.
>
>    $ LD_PRELOAD=/path/to/darshan/lib/libdarshan.so ./myapp
>
>    Add the FORTRAN library as well if you are profiling FORTRAN code. You can also export LD_PRELOAD it with the proper mpirun options.
>
> kevin
>
> -----Original Message-----
> From: <darshan-users-bounces at lists.mcs.anl.gov> on behalf of "Suman, Preeti" <preeti.suman at intel.com>
> Date: Monday, October 24, 2016 at 4:01 PM
> To: "darshan-users at lists.mcs.anl.gov" <darshan-users at lists.mcs.anl.gov>
> Subject: [Darshan-users] Segmentation fault with Darshan-3.1.1
>
>      Hello,
>       
>      With Darshan-3.1.1, compiled with GCC-5.1 or Intel-17 compilers on KNL, when LD_PRELOAD=<path_to>/darshan-runtime/lib/libdarshan.so is set, I am getting a segmentation fault whenever I do ‘ls’.
>      Example:
>      bash-4.2$ ls
>      Segmentation fault (core dumped)
>       
>      Have you encountered this before?
>      For version-3.1.1 is it recommended to build Darshan with
>      --disable-ld-preload
>      ?
>       
>      Thanks,
>      Preeti Suman
>      Software Development Engineer,
>      Systems Engineering, Architecture & Runtimes
>      Email:
>      preeti.suman at intel.com <mailto:preeti.suman at intel.com>
>       
>      
>      
>
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