Practical Session: Debugging

Follow the instructions from the practical session page: https://github.com/sc-camp/2015-debug

0 - Pre-requisites

Configure your connection to Guane cluster

Edit the file ~/.ssh/config (create it if it does not already exist) and adding the following entries:

	Host toctoc
	        User *yourlogin*
	        Hostname toctoc.sc3.uis.edu.co
	        ForwardX11 yes

	Host guane
	        User *yourlogin*
	        Hostname guane
	        ForwardX11 yes
	        ProxyCommand ssh -q toctoc "nc -q 0 %h %p"

Now you shall be able to issue the following command to connect to the cluster and obtain the welcome banner:

	(laptop)$> ssh guane

In the sequel, we assume these aliases to be defined.

Connect to a node of the Guane cluster

The first step is the reservation of a resource. Connect to the cluster frontend

(laptop)$> ssh guane

Once connected to the user frontend, book 1 core for 3 hours

jdoe@guane:~$ oarsub -I -l core=1,walltime="03:00:00"

When the job is running, you can start the practical session.

1 - GDB Tutorial

Tutorial from A GDB Tutorial with Examples

2 - Valgrind Tutorial

Tutorial from Using Valgrind to Find Memory Leaks and Invalid Memory Use

3 - Bug Hunting

A list of programs demonstrating the different kind of bus are available in the exercises directory. Try the different debugging tools on every example to see how they behave and find the bugs.

Run the following command to download all the exercises:

git clone https://github.com/sc-camp/2015-debug.git sc-camp-2015-debug

Notes:

• You can compile each program manually using gcc or icc. You are encouraged to try both to see how differently they behave. Example: gcc program.c -o program. Add any additional parameter you might need.

• Some program required additional options to be compiled. They are indicated in comment at the beginning of each source file.