Parallel Debuggers are important tools when trying to eliminate bugs in parallel programs. Commercial parallel debuggers are expensive. In this blog post I will show you a free and open source alternative which is good enough for education purposes and for small codes. Suppose you want to debug the famous cpi.c code which computes an approximation to pi by a parallel numerical integration. This demo uses the free Data Display Debugger (ddd) which is based on gdb but has a nice GUI. Step 1, compile: mpicc -g -o cpi ./cpi.c Step 2, run (without a debugger): mpirun -np 2 ./cpi Step 3, run with the free Data Display Debugger (ddd) : mpirun -np 2 ddd ./cpi The last command will open two MPI processes (instances) of ddd each running cpi, see screen capture: Finally, I enclose here a short video which I hope is convincing: hi-res version: https://youtu.be/N_J4NKJkuMs Happy (Free) MPI debugging!
HPL Benchmark on my laptop It's the Top500 season time. I therefore tested HPL on my laptop using Intel's latest OneAPI version 2021.1.10.2261. The laptop specifications are obtained from lscpu : $ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 39 bits physical, 48 bits virtual CPU(s): 8 On-line CPU(s) list: ...
Nice profiling using TAU from U. of Oregon This tool together with many other useful Parallel Processing tools and packages are available as a single VirtualBox ova image here from Vi-HPS . You may also be interested to visit Paratools (HPCLinux) website.
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