Improve MG PageRank scalability (#2038)

Improve MG PageRank performance & scalability in multi-node many GPU systems

Authors:
  - Seunghwa Kang (https://github.com/seunghwak)

Approvers:
  - Chuck Hastings (https://github.com/ChuckHastings)
  - Andrei Schaffer (https://github.com/aschaffer)
  - Kumar Aatish (https://github.com/kaatish)

URL: #2038

cpp/CMakeLists.txt

@@ -230,7 +230,6 @@ add_library(cugraph SHARED
  src/structure/create_graph_from_edgelist_mg.cu
  src/structure/symmetrize_edgelist_sg.cu
  src/structure/symmetrize_edgelist_mg.cu
- src/utilities/host_barrier.cpp
  src/visitors/graph_envelope.cpp
  src/visitors/visitors_factory.cpp
  src/visitors/bfs_visitor.cpp

cpp/include/cugraph/prims/copy_to_adj_matrix_row_col.cuh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2021, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2022, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -170,7 +170,7 @@ void copy_to_matrix_major(raft::handle_t const& handle,
  matrix_partition_device_view_t<vertex_t, edge_t, weight_t, GraphViewType::is_multi_gpu>(
  graph_view.get_matrix_partition_view(i));
 
- if (col_comm_rank == i) {
+ if (i == col_comm_rank) {
  auto vertex_partition =
  vertex_partition_device_view_t<vertex_t, GraphViewType::is_multi_gpu>(
  graph_view.get_vertex_partition_view());
@@ -365,7 +365,7 @@ void copy_to_matrix_minor(raft::handle_t const& handle,
  matrix_partition_device_view_t<vertex_t, edge_t, weight_t, GraphViewType::is_multi_gpu>(
  graph_view.get_matrix_partition_view(size_t{0}));
  for (int i = 0; i < row_comm_size; ++i) {
- if (row_comm_rank == i) {
+ if (i == row_comm_rank) {
  auto vertex_partition =
  vertex_partition_device_view_t<vertex_t, GraphViewType::is_multi_gpu>(
  graph_view.get_vertex_partition_view());