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Debugging Tools

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jgp edited this page Sep 30, 2019 · 2 revisions

Several debugging tools are available on Piz Daint:

ARM Forge/DDT

ARM DDT

  • DDT provides source-level debugging of Fortran, C, and C++ codes. It can be used for debugging serial, multi-threaded (OpenMP), multi-process (MPI) and accelerator based (Cuda, OpenACC) programs. It can be executed either as a graphical user interface (ddt --connect client mode) or from the command-line (ddt --offline mode).

To use ddt on Piz Daint, load the modulefile:

module load craype-accel-nvidia60
module swap cudatoolkit/9.2.148_3.19-6.0.7.1_2.1__g3d9acc8
module load ddt/19.1.3-Suse-12.0

ddt -v
    Arm DDT
    Part of Arm Forge. Copyright (c) 2002-2019 Arm Limited (or its affiliates).
    All rights reserved.
    Version: 19.1.3

For further information check the documentation:

or read further:

ddt with mpi+cuda

  • Install the client on your laptop
  • Load the modulefiles
  • Compile and link your code with cuda: nvcc -G and CC -g
  • Add ddt to your jobscript
ddt --connect srun ./exe

Start the ddt client on your laptop and use it to connect to Piz Daint: ddtTunnel

Launch the debugging session: ddtcudarun

ddt will stop in the first cuda kernel reached: ddtcudabkp

start debugging your cuda code: ddtcudakernel

ddt with mpi+openacc

  • Install the client on your laptop
  • Load the modulefiles
module load daint-gpu
module unload PrgEnv-cray
module load PrgEnv-pgi
module load craype-accel-nvidia60
module load ddt/19.1.3-Suse-12.0
module unload cudatoolkit
module load cudatoolkit/9.2.148_3.19-6.0.7.1_2.1__g3d9acc8
export CRAYPE_LINK_TYPE=dynamic
export OMP_NUM_THREADS=1
export ALLINEA_FORCE_CUDA_VERSION=9.2
export PATH=/opt/cray/pe/cce/8.7.3/binutils/x86_64/bin:$PATH

CC -std=c++14 -g -O1 -acc -ta=tesla:cc60,debug sqpatch.cpp
  • Compile and link your code with cuda: CC -g
  • Add ddt to your jobscript
ddt --connect srun ./exe

ddtopenacc

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