From: Bruno Turcksin <bruno.turcksin@gmail.com>
Date: Mon, 8 Jul 2019 00:54:00 +0000 (+0000)
Subject: Add explanation on the use of __synchtreads()
X-Git-Tag: v9.2.0-rc1~1408^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F8337%2Fhead;p=dealii.git

Add explanation on the use of __synchtreads()
---

diff --git a/include/deal.II/matrix_free/cuda_hanging_nodes_internal.h b/include/deal.II/matrix_free/cuda_hanging_nodes_internal.h
index 9a9b828749..8abf9b68ec 100644
--- a/include/deal.II/matrix_free/cuda_hanging_nodes_internal.h
+++ b/include/deal.II/matrix_free/cuda_hanging_nodes_internal.h
@@ -830,6 +830,8 @@ namespace CUDAWrappers
               }
           }
 
+        // The synchronization is done for all the threads in one block with
+        // each block being assigned to one element.
         __syncthreads();
 
         if (constrained_face && constrained_dof)