Add documentation on the "Building MFEM" page for cmake install #291
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Based on information provided in the INSTALL file and CMake documentation Followed the directory structure in the Makefile based tutorial
| cmake .. -DMFEM_USE_CUDA=YES | ||
| ``` | ||
| Note that this requires CMake 3.8 or newer | ||
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| To specify what CUDA architecture to target: | |
| ```sh | |
| cmake .. -DCUDA_ARCH="sm_70" | |
| ``` | |
| The CUDA architecture is formatted as `sm_{CC}`, where CC is the GPU compute capability of the target GPU without the decimal point. A list of Nvidia GPU compute capabilities can be found in [the Nividia developers documentation](https://developer.nvidia.com/cuda-gpus). |
TODO: currently I think MFEM's CMake setup doesn't allow targeting multiple CUDA architectures at once. I think we should fix this?
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There is a CMake 3.18 target property CUDA_ARCHITECTURES that allows semicolon separated lists https://cmake.org/cmake/help/latest/prop_tgt/CUDA_ARCHITECTURES.html
Right now it looks like mfem manually sets the -arch flag. From the nvcc compiler documentation it seems like it might take comma separated lists if the format is the same as the --gpu-code flag. I don't have access to cuda enabled machines to try this out right now.
The all, all-major, and native options for the architecture may be worth mentioning.
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I expanded support for all, all-major, and native as well as multiple specific cuda architectures in this PR: pr4561.
Supported formats now include:
-DCUDA_ARCH="all"
-DCUDA_ARCH="all-major"
-DCUDA_ARCH="native"
-DCUDA_ARCH="{ARCH1},{ARCH2},..."
-DCUDA_ARCH="{ARCH1};{ARCH2};..."
where ARCHN can be either just the CC number (70, 86, etc.), or optionally prefixed with sm_ (sm_70, sm_86, etc.).
This should work even for CMake older than 3.18 (the current CMakeLists minimum version is 3.8).
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looks great, added some documentation for this!
Co-authored-by: Andrew Ho <[email protected]>
| @@ -239,3 +239,99 @@ git clone https://github.com/spack/spack.git | |||
| cd spack | |||
| ./bin/spack install -v mfem | |||
| ``` | |||
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| ## Building MFEM with CMake | |||
| To build a serial form of MFEM with CMake first create a build directory. For example, using a build directory named `build`: | |||
| cmake --build . -j 4 | ||
| ``` | ||
| ### Parallel build using CMake | ||
| To build a parallel form of MFEM with CMake first build METIS and Hypre as described above. |
| To build a parallel form of MFEM with CMake first build METIS and Hypre as described above. | ||
| From the MFEM source directory, create a build directory. For example, using a build directory named `build`: | ||
| ```sh | ||
| cd mfem-4.5 |
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don't add versions to general instructions
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This was something I had a question about while writing this, the Makefile section of these instructions assume mfem-4.5, should I stick to that convention or use "MFEM_DIR", and should the Makefile instructions do the same?
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| Run the CMake configuration on the MFEM source directory using the `MFEM_USE_MPI` CMake variable to enable MPI. | ||
| This will automatically search for the system MPI implementation, the METIS installation (in `<mfem-source-dir>/../metis-4.0`), and Hypre installation (in `<mfem-source-dir/../hypre`). |
| cmake --build . -j 4 | ||
| ``` | ||
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| ### Alternate configuration steps |
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s/Alternate/Alternative
or "Advanced"?
Based on information provided in the INSTALL file and CMake documentation.
Followed the directory structure in the Makefile based tutorial
Closes issue #290