Fixing cusparse aligned address issue and adding note

cpp/include/raft/sparse/linalg/spmm.hpp

@@ -72,6 +72,10 @@ void spmm(raft::resources const& handle,
 
   detail::spmm(handle, trans_x, trans_y, is_row_major, alpha, descr_x, descr_y, beta, descr_z);
 
+  // WARNING: Do not remove the following copy unless you can, with certainty, say that
+  // the underlying cuSPARSE issue affecting CUDA 12.2+ has been resolved.
+  raft::copy(
+    z.data_handle(), z_tmp.data_handle(), z_tmp.size(), raft::resource::get_cuda_stream(handle));
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroySpMat(descr_x));
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroyDnMat(descr_y));
   RAFT_CUSPARSE_TRY_NO_THROW(cusparseDestroyDnMat(descr_z));

cpp/test/CMakeLists.txt

@@ -101,9 +101,11 @@ if(BUILD_TESTS)
     PATH
     test/cluster/kmeans.cu
     test/cluster/kmeans_balanced.cu
+          test/cluster/kmeans_find_k.cu
     test/cluster/cluster_solvers.cu
     test/cluster/linkage.cu
-    test/cluster/kmeans_find_k.cu
+    test/cluster/spectral.cu
+
     LIB
     EXPLICIT_INSTANTIATE_ONLY
   )

cpp/test/cluster/cluster_solvers_deprecated.cu

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

cpp/test/cluster/spectral.cu

@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2020-2024, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+#include <iostream>
+#include <memory>
+#include <raft/core/handle.hpp>
+#include <raft/spectral/modularity_maximization.cuh>
+#include <raft/spectral/partition.cuh>
+
+namespace raft {
+namespace cluster {
+
+/**
+ * Warning: There appears to be a CUDA 12.2 bug in cusparse that causes an
+ * alignment issue. We've fixed the bug in our code through a workaround
+ * (see raft/sparse/linalg/spmm.hpp for fix). This test is meant to fail
+ * in the case where the fix is accidentally reverted, so that it doesn't
+ * break any downstream libraries that depend on RAFT
+ */
+TEST(Raft, Spectral)
+{
+  raft::handle_t handle;
+
+  std::vector<int32_t> h_offsets({0, 2, 4, 7, 10, 12, 14});
+  std::vector<int32_t> h_indices({1, 2, 0, 2, 0, 1, 3, 2, 4, 5, 3, 5, 3, 4});
+  std::vector<float> h_values(
+    {1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0});
+  std::vector<int32_t> expected_clustering({1, 1, 1, 0, 0, 0});
+
+  int32_t n_clusters{2};
+  int32_t n_eigenvectors{2};
+  int32_t evs_max_it{100};
+  int32_t kmean_max_it{100};
+  int32_t restartIter_lanczos = 15 + n_eigenvectors;
+  float evs_tol{0.001};
+  float kmean_tol{0.001};
+  unsigned long long seed1{1234567};
+  unsigned long long seed2{12345678};
+  bool reorthog{false};
+
+  rmm::device_uvector<int32_t> offsets(h_offsets.size(), handle.get_stream());
+  rmm::device_uvector<int32_t> indices(h_indices.size(), handle.get_stream());
+  rmm::device_uvector<float> values(h_indices.size(), handle.get_stream());
+  rmm::device_uvector<int32_t> clustering(expected_clustering.size(), handle.get_stream());
+  rmm::device_uvector<float> eigenvalues(n_eigenvectors, handle.get_stream());
+  rmm::device_uvector<float> eigenvectors(n_eigenvectors * expected_clustering.size(),
+                                          handle.get_stream());
+
+  rmm::device_uvector<int32_t> exp_dev(expected_clustering.size());
+
+  raft::update_device(
+    exp_dev.data(), expected_clustering.data(), expected_clustering.size(), handle.get_stream());
+
+  raft::update_device(offsets.data(), h_offsets.data(), h_offsets.size(), handle.get_stream());
+  raft::update_device(indices.data(), h_indices.data(), h_indices.size(), handle.get_stream());
+  raft::update_device(values.data(), h_values.data(), h_values.size(), handle.get_stream());
+
+  raft::spectral::matrix::sparse_matrix_t<int32_t, float> const matrix{
+    handle,
+    offsets.data(),
+    indices.data(),
+    values.data(),
+    static_cast<int32_t>(offsets.size() - 1),
+    static_cast<int32_t>(indices.size())};
+
+  raft::spectral::eigen_solver_config_t<int32_t, float> eig_cfg{
+    n_eigenvectors, evs_max_it, restartIter_lanczos, evs_tol, reorthog, seed1};
+  raft::spectral::lanczos_solver_t<int32_t, float> eig_solver{eig_cfg};
+
+  raft::spectral::cluster_solver_config_t<int32_t, float> clust_cfg{
+    n_clusters, kmean_max_it, kmean_tol, seed2};
+  raft::spectral::kmeans_solver_t<int32_t, float> cluster_solver{clust_cfg};
+
+  raft::spectral::partition(handle,
+                            matrix,
+                            eig_solver,
+                            cluster_solver,
+                            clustering.data(),
+                            eigenvalues.data(),
+                            eigenvectors.data());
+
+  ASSERT_TRUE(devArrMatch(expected_clustering.data(),
+                          exp_dev.data(),
+                          exp_dev.size(),
+                          1,
+                          raft::Compare<int32_t>(),
+                          stream));
+}
+
+}  // namespace cluster
+}  // namespace raft