From 25bff5949b34430aa173f3819529e2924ec76a20 Mon Sep 17 00:00:00 2001
From: Dmitri Naumov <github@naumov.de>
Date: Fri, 1 Nov 2024 11:19:15 +0100
Subject: [PATCH] [MeL] Use BaseLib::MPI::allgatherv
---
.../transformMeshToNodePartitionedMesh.cpp | 31 +++++--------------
1 file changed, 8 insertions(+), 23 deletions(-)
diff --git a/MeshLib/Utils/transformMeshToNodePartitionedMesh.cpp b/MeshLib/Utils/transformMeshToNodePartitionedMesh.cpp
index 477566dd5b6..4a8fed12f10 100644
--- a/MeshLib/Utils/transformMeshToNodePartitionedMesh.cpp
+++ b/MeshLib/Utils/transformMeshToNodePartitionedMesh.cpp
@@ -180,34 +180,19 @@ std::vector<std::size_t> computeGhostBaseNodeGlobalNodeIDsOfSubDomainPartition(
}
}
- // send ids of bulk ghost nodes belonging to the subdomain mesh to all
- // other ranks and at the same time receive from all other ranks
- // first send the sizes to all other to are able to allocate buffer
- auto const size = subdomain_node_id_to_bulk_node_id.size();
- std::size_t const global_number_of_subdomain_node_id_to_bulk_node_id =
- BaseLib::MPI::allreduce(size, MPI_SUM, mpi);
+ // Send ids of bulk ghost nodes belonging to the subdomain mesh to all
+ // other ranks and at the same time receive from all other ranks.
+ std::vector<std::size_t> ghost_node_ids_of_all_ranks;
+ std::vector<int> const offsets =
+ BaseLib::MPI::allgatherv(std::span{subdomain_node_id_to_bulk_node_id},
+ ghost_node_ids_of_all_ranks, mpi);
+ std::size_t const global_number_of_subdomain_node_id_to_bulk_node_id =
+ offsets.back();
DBUG("[{}] global_number_of_subdomain_node_id_to_bulk_node_id: '{}' ",
subdomain_mesh->getName(),
global_number_of_subdomain_node_id_to_bulk_node_id);
- std::vector<int> const numbers_of_ids_at_ranks =
- BaseLib::MPI::allgather(static_cast<int>(size), mpi);
-
- std::vector<int> const offsets =
- BaseLib::sizesToOffsets(numbers_of_ids_at_ranks);
-
- std::vector<std::size_t> ghost_node_ids_of_all_ranks(
- global_number_of_subdomain_node_id_to_bulk_node_id);
- MPI_Allgatherv(subdomain_node_id_to_bulk_node_id.data(), /* sendbuf */
- size, /* sendcount */
- MPI_UNSIGNED_LONG, /* sendtype */
- ghost_node_ids_of_all_ranks.data(), /* recvbuf (out) */
- numbers_of_ids_at_ranks.data(), /* recvcounts */
- offsets.data(), /* displs */
- MPI_UNSIGNED_LONG, /* recvtype */
- mpi.communicator);
-
// construct a map for fast search of local bulk node ids
std::map<std::size_t, std::size_t> global_to_local_bulk_node_ids;
for (auto const id : bulk_mesh->getNodes() | MeshLib::views::ids)
--
GitLab