https://github.com/tudasc/mpi-precompute
https://github.com/tudasc/mpi-precompute
Last synced: 2 months ago
JSON representation
- Host: GitHub
- URL: https://github.com/tudasc/mpi-precompute
- Owner: tudasc
- Created: 2024-05-06T09:20:50.000Z (about 1 year ago)
- Default Branch: precompute-release
- Last Pushed: 2024-05-06T09:28:34.000Z (about 1 year ago)
- Last Synced: 2025-01-17T15:52:46.331Z (4 months ago)
- Language: C++
- Size: 2.73 MB
- Stars: 0
- Watchers: 4
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: Readme.md
Awesome Lists containing this project
README
# Compiler-Based Precalculation of MPI Message Envelopes
This Repository contains the llvm pass that inserts the precalculation of MPI message tags into an
application [[1]](ref-1), alongside the openmpi patch developed in [[2]](ref-2) and MUrB (
by [Adrien Cassange](https://largo.lip6.fr/~cassagnea/)) as an example application to showcase the pass.
## Prerequisites
For this Project, we used clang/`llvm 16.0.1`
`openmpi 4.1.1` will be downloaded and build during the cmake build step (see below)
## Building
Before Building with cmake, one may need to have a look at [openmpi-patch/CMakeLists.txt](openmpi-patch/CMakeLists.txt)
and change the ``OMPI_CONFIGURE_FLAGS`` variable to fit their system.
The variable is used to configure openmpi.
After one had adjusted the openmpi configuration, building with cmake is quite straightforward:
```
mkdir build && cd build
cmake ..
make -j
source setup_env.sh
ctest # run the tests to check if build was successful
```
## Usage
The build step creates a ``setup_env.sh`` file, that sets the required environment variables.
To build an application with the pass, replace the compiler to use with ``clang_wrap_cc`` or ``clang_wrap_cxx``
respectively.
The ``setup_env.sh`` automatically sets the compiler to use with ``mpicc`` and ``mpicxx`` to those wrappers.
In order to activate the pass, one needs to supply the environment
variable ``export USE_MPI_COMPILER_ASSISTANCE_PASS=true``
The compile step needs the following command line arguments to work
correctly ``-fno-inline -flto -fwhole-program-vtables``.
The ``-fno-inline`` will be removed after the analysis, so that inlining does happen.
## Build of MUrB example application
Before building MUrB be sure to init the submodules (``git submodule update --init --recursive``) to download the
prerequisite requirements; also refer to the [Readme](sample_apps/MUrB/README.md) in the MUrB directory.
MUrB can then be built using cmake, we used the following build settings with our Pass:
```
cmake .. -DCMAKE_CXX_COMPILER=$MPICXX -DCMAKE_CXX_FLAGS="-fopenmp -O3 -fno-inline -fuse-ld=lld -flto -fwhole-program-vtables" -DENABLE_MURB_MPI=ON -DENABLE_VISU=OFF -DENABLE_MURB_READER=OFF
mpirun -n 2 ./bin/murb -v --im 100 -i 10 -n 100 # to test if it runs
```
The file [sample_apps/scripts/showcase_experiment.sh](sample_apps/scripts/showcase_experiment.sh) details all steps
required to reproduce our measurements from [[1]](ref-1)
#### References
[1]
Tim Jammer, Tim Heldmann, Michael Blesel, Michael Kuhn, Christian Bischof, "Compiler-Based Precalculation of MPI Message Envelopes" To Appear In: ISC High Performance 2024 International Workshops
[2]
Tim Jammer and Christian Bischof "Compiler-enabled optimization of persistent MPI Operations" In : 2022 IEEE/ACM International Workshop on Exascale MPI (ExaMPI) https://doi.org/10.1109/ExaMPI56604.2022.00006