Segmentation fault when using cusolverSpScsrlsvchol in CUDA for sparse linear problems

Question

I'm trying to port a linear problem to CUDA in order to speed up solving times. I have successfully used cusolverDn to handle dense problems on the GPU. However, when I attempted to apply it to sparse problems using cusolverSpScsrlsvchol, I keep getting a segmentation fault.

To debug the issue, I used the CUDA compute sanitizers and received the following output:

$ /c/Programme/NVIDIA\ GPU\ Computing\ Toolkit/CUDA/v11.7/bin/compute-sanitizer.bat --tool memcheck bin/FEMaster_gpu.exe
========= COMPUTE-SANITIZER

========= Error: process didn't terminate successfully
========= Target application returned an error
========= ERROR SUMMARY: 0 errors
Segmentation fault

I narrowed down the problem to the following minimal code snippet:

cusolverSpHandle_t handle_cusolver_sp;
    cusparseHandle_t   handle_cusparse;

    // loading handles
    cusolverSpCreate(&handle_cusolver_sp);
    cusparseCreate  (&handle_cusparse);

    // get properties
    cudaSetDevice(0);

    // create csr arrays on cpu
    float host_csr_values[4]{1,1,1,1};
    int   host_csr_col_id[4]{0,1,2,3};
    int   host_csr_row_pt[5]{0,1,2,3,4};
    float host_rhs       [4]{0,3,7,1};
    int   host_singular  [1]{0};

    // allocate arrays on the gpu
    float* dev_csr_values;
    int  * dev_csr_col_id;
    int  * dev_csr_row_pt;
    float* dev_rhs;
    int  * dev_singular;

    runtime_assert_cuda(cudaMalloc((void**) &dev_csr_values,4 * sizeof(float)));
    runtime_assert_cuda(cudaMalloc((void**) &dev_csr_col_id,4 * sizeof(int  )));
    runtime_assert_cuda(cudaMalloc((void**) &dev_csr_row_pt,5 * sizeof(int  )));
    runtime_assert_cuda(cudaMalloc((void**) &dev_rhs       ,4 * sizeof(float)));
    runtime_assert_cuda(cudaMalloc((void**) &dev_singular  ,1 * sizeof(int  )));

    // move data to gpu
    runtime_assert_cuda(cudaMemcpy(dev_csr_values, host_csr_values, 4 * sizeof(float), cudaMemcpyHostToDevice));
    runtime_assert_cuda(cudaMemcpy(dev_csr_col_id, host_csr_col_id, 4 * sizeof(int  ), cudaMemcpyHostToDevice));
    runtime_assert_cuda(cudaMemcpy(dev_csr_row_pt, host_csr_row_pt, 5 * sizeof(int  ), cudaMemcpyHostToDevice));
    runtime_assert_cuda(cudaMemcpy(dev_rhs       , host_rhs       , 4 * sizeof(float), cudaMemcpyHostToDevice));

    // create matrix descriptor
    cusparseMatDescr_t descr;
    runtime_assert_cuda(cusparseCreateMatDescr(&descr));
    runtime_assert_cuda(cusparseSetMatType     (descr, CUSPARSE_MATRIX_TYPE_GENERAL));
    runtime_assert_cuda(cusparseSetMatIndexBase(descr, CUSPARSE_INDEX_BASE_ZERO    ));

    runtime_assert_cuda(cusolverSpScsrlsvchol(handle_cusolver_sp,
                                              4,
                                              4,
                                              descr,
                                              dev_csr_values,
                                              dev_csr_row_pt,
                                              dev_csr_col_id,
                                              dev_rhs,
                                              0,    // tolerance
                                              0,    // reorder
                                              dev_rhs,
                                              dev_singular));

The values I put in there for the sparse matrix is the one for a diagonal matrix.

I removed the memory deallocation, output retrieval, and other similar calls for simplicity. The code seems straightforward, but it results in a segmentation fault. The issue occurs specifically during the call to cusolverSpScsrlsvchol.

I've been stuck on this problem for over a day and I can't figure out why it's not working. Any help would be greatly appreciated!

Answer 1

The API states that the singularity parameter is supposed to be in host memory space, not device.