Change MPI block size and minor SYCL document update

3dem · Nov 1, 2023 · 1343fa3 · 1343fa3
1 parent da8ee23
commit 1343fa3
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/README_sycl.md b/README_sycl.md
@@ -35,7 +35,6 @@ $ cmake \
 -DCMAKE_BUILD_TYPE=Release \
 -DCMAKE_C_FLAGS="-O3" \
 -DCMAKE_CXX_FLAGS="-O3 -march=native" \
--DCMAKE_EXE_LINKER_FLAGS="-O3 -march=native" \
 ..
 
 $ #### This is Intel GPU Level Zero backend specific #####

diff --git a/src/mpi.cpp b/src/mpi.cpp
@@ -108,9 +108,10 @@ MpiNode::MpiNode(int &argc, char ** argv)
 	MPI_Comm_create_group(MPI_COMM_WORLD, root_evenG, 1, &root_evenC);
 	MPI_Comm_create_group(MPI_COMM_WORLD, root_oddG, 2, &root_oddC);
 
-	constexpr std::ptrdiff_t defBlock = RELION_MPI_MAX_SIZE;	// default for MPI communication
+	constexpr std::ptrdiff_t defPtBlock = 4ULL*1024*1024*1024;	// 4 GiB, default for MPI communication
+	constexpr std::ptrdiff_t defColBlock = 64*1024*1024;		// 64 MiB, default for MPI communication
 	constexpr std::ptrdiff_t maxPtBlock = 8ULL*1024*1024*1024;		// 8 GiB, max for MPI pt-2-pt. Normal limit is sizeof(variable) * INT_MAX bytes
-	constexpr std::ptrdiff_t maxCollBlock = 4ULL*1024*1024*1024;	// 4 GiB, max for MPI collective. Normal limit is sizeof(variable) * INT_MAX bytes
+	constexpr std::ptrdiff_t maxCollBlock = 1ULL*1024*1024*1024;	// 1 GiB, max for MPI collective. Normal limit is sizeof(variable) * INT_MAX bytes
 
 	// User input to change default MPI communication blocking size
 	char* pEnvBlock = std::getenv("MAX_MPI_BLOCK");     // For both pt-2-pt and collective
@@ -144,7 +145,7 @@ MpiNode::MpiNode(int &argc, char ** argv)
 				p2p_blocksize = maxPtBlock;
 		}
 		else
-			p2p_blocksize = defBlock;
+			p2p_blocksize = defPtBlock;
 
 		if (lColl > 0)  // "MAX_MPI_COLL_BLOCK" is set
 		{
@@ -154,7 +155,7 @@ MpiNode::MpiNode(int &argc, char ** argv)
 				coll_blocksize = maxCollBlock;
 		}
 		else
-			coll_blocksize = defBlock;
+			coll_blocksize = defColBlock;
 	}
 	// Make it multiple of 8 bytes
 	p2p_blocksize = (p2p_blocksize / 8ULL) * 8ULL;