gmres_aux.cu

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/*
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#include <stdio.h>
#include "gmres_kernel.h"
#include <device/device_config.h>
#include <device/cuda/check.h>
 
#ifdef HAVE_NVSHMEM
#include <nvshmem.h>
#include <nvshmemx.h>
#endif
 
extern "C" {
 
#include <math/bcknd/device/device_mpi_reduce.h>
#include <math/bcknd/device/device_mpi_op.h>
 
#ifdef HAVE_NCCL
#include <math/bcknd/device/device_nccl_reduce.h>
#include <math/bcknd/device/device_nccl_op.h>
#endif
 
  real * gmres_bf1 = NULL;
  real * gmres_bfd1 = NULL;
  int gmres_bf_len = 0;
 
  real cuda_gmres_part2(void *w, void *v, void *h, void * mult, int *j, int *n) {
 
    const dim3 nthrds(1024, 1, 1);
    const dim3 nblcks(((*n)+1024 - 1)/ 1024, 1, 1);
    const int nb = ((*n) + 1024 - 1)/ 1024;
    const cudaStream_t stream = (cudaStream_t) glb_cmd_queue;
 
    if (gmres_bf1 != NULL && gmres_bf_len < nb) {
      CUDA_CHECK(cudaFreeHost(gmres_bf1));
#ifdef HAVE_NVSHMEM
      nvshmem_free(gmres_bfd1);
#else
      CUDA_CHECK(cudaFree(gmres_bfd1));
#endif
      gmres_bf1 = NULL;
    }
 
    if (gmres_bf1 == NULL){
      CUDA_CHECK(cudaMallocHost(&gmres_bf1, nb*sizeof(real)));
#ifdef HAVE_NVSHMEM
      gmres_bfd1 = (real *) nvshmem_malloc(nb*sizeof(real));
#else
      CUDA_CHECK(cudaMalloc(&gmres_bfd1, nb*sizeof(real)));
#endif
      gmres_bf_len = nb;
    }
 
    gmres_part2_kernel<real>
      <<<nblcks, nthrds, 0, stream>>>((real *) w, (real **) v,
                                      (real *) mult,(real *) h,
                                      (real *) gmres_bfd1, *j, *n);
    CUDA_CHECK(cudaGetLastError());
    reduce_kernel<real><<<1, 1024, 0, stream>>>((real *) gmres_bfd1, nb);
    CUDA_CHECK(cudaGetLastError());
 
#ifdef HAVE_NCCL
    device_nccl_allreduce(gmres_bfd1, gmres_bfd1, 1, sizeof(real),
                          DEVICE_NCCL_SUM, stream);
    CUDA_CHECK(cudaMemcpyAsync(gmres_bf1, gmres_bfd1, sizeof(real),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#elif HAVE_NVSHMEM
    if (sizeof(real) == sizeof(float)) {
      nvshmemx_float_sum_reduce_on_stream(NVSHMEM_TEAM_WORLD,
                                           (float *) gmres_bfd1,
                                           (float *) gmres_bfd1, 1, stream);
    }
    else if (sizeof(real) == sizeof(double)) {
      nvshmemx_double_sum_reduce_on_stream(NVSHMEM_TEAM_WORLD,
                                           (double *) gmres_bfd1,
                                           (double *) gmres_bfd1, 1, stream);
    }
    CUDA_CHECK(cudaMemcpyAsync(gmres_bf1, gmres_bfd1, sizeof(real),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#elif HAVE_DEVICE_MPI
    cudaStreamSynchronize(stream);
    device_mpi_allreduce(gmres_bfd1, gmres_bf1, 1, sizeof(real), DEVICE_MPI_SUM);
#else
 
    CUDA_CHECK(cudaMemcpyAsync(gmres_bf1, gmres_bfd1, sizeof(real),
                               cudaMemcpyDeviceToHost, stream));
    cudaStreamSynchronize(stream);
#endif
    return gmres_bf1[0];
  }
  real cuda_gmres_part2(void *w, void *v, void *h, void * mult, int *j, int *n) {…}
}