From 7db7847b1f2a74cd7de4113f8da7c667ce86df64 Mon Sep 17 00:00:00 2001 From: Daniel Arndt Date: Fri, 10 May 2019 11:12:24 -0400 Subject: [PATCH] Be a bit more verbose documenting DEAL_II_MPI_WITH_CUDA_SUPPORT --- doc/external-libs/cuda.html | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/doc/external-libs/cuda.html b/doc/external-libs/cuda.html index 54605dda39..67d3834b8c 100644 --- a/doc/external-libs/cuda.html +++ b/doc/external-libs/cuda.html @@ -56,15 +56,20 @@

- In order to enable MPI Cuda support (provided that your MPI library - supports it) configure with: + Several MPI implementations are able to perform MPI operations with data + located in device memory directly without the need to copy to CPU memory + explicitly first. This feature is commonly known as "CUDA-aware MPI". + In case deal.II is compiled with MPI support and the MPI implementation + supports this feature, you can tell deal.II to use it by configuring with 

 
         -DDEAL_II_WITH_CUDA=ON
         -DDEAL_II_WITH_MPI=ON
         -DDEAL_II_MPI_WITH_CUDA_SUPPORT=ON
- This configuration option is currently not autodetected. + Note, that there is no check that detects if the MPI implementation + really is CUDA-aware. Activating this flag for incompatible MPI libraries + will lead to segmentation faults in MPI calls.

-- 2.39.5