cpplattica

Building the Code

Locally on MacOS

Next step is to build the code. We'll follow a CMake tree build:

> mkdir build
> cd build

Next step is configure the build in either Debug mode or Release mode.

> cmake -DCMAKE_BUILD_TYPE=Release ..

Once the build is configured, we may actually execute the build:

> make

Debugging with LLDB

Configure the build in debug mode:

> cmake -DCMAKE_BUILD_TYPE=Debug ..

Once the build is configured, we may actually execute the build:

> make

Activate lldb with executable file:

> lldb ./mpi

General debugging commands

Set a breakpoint in a specific file:

> breakpoint set --file /Users/xavi/Documents/grad_school/CS267/final_project/cpplattica/main.cpp --line 39

Online resource, LLBDB Quick Reference

On NERSC

First make sure the CMake module is loaded:

> module load cmake

If the armadillo dependency is not installed download the tar from the website and untar. Change directory the resulting library. Follow the cmake installation instructions in the README. Make sure the library is in the include path. For example,

> export CMAKE_PREFIX_PATH=$CMAKE_PREFIX_PATH:/global/homes/x/xlinn/armadillo-12.8.4

Next step is to build the code. We'll follow a CMake tree build:

> mkdir build
> cd build

Next step is configure the build in either Debug mode or Release mode.

> cmake -DCMAKE_BUILD_TYPE=Release ..

Once the build is configured, we may actually execute the build:

> make

Running the Code

You will need to test on at most two nodes for this assignment. To allocate two interactive KNL nodes instead of just one (as we did in previous assignments), the syntax is simple:

build> salloc -N 2 -C cpu -q interactive -t 01:00:00

srun -N 2 --ntasks-per-node=2 ./mpi

Viewing current jobs on NERSC

To view current user jobs:

squeue -u $USER

To cancel a specific job:

scancel $JobID

Debugging with GDB

Set breakpoint on a specific file and line:

break /global/homes/x/xlinn/cpplattica/src/synchronous_runner.cpp:37

Print variables:

Resources

• MPI 3.1 docs