Better multi-node communication: fire and forget.

This commit is contained in:
jpekkila
2019-10-17 18:17:37 +03:00
parent 3d852e5082
commit 26bbfa089d

View File

@@ -873,7 +873,59 @@ acDeviceCommunicateHalosMPI(const Device device)
const size_t count = device->local_config.int_params[AC_mx] * const size_t count = device->local_config.int_params[AC_mx] *
device->local_config.int_params[AC_my] * NGHOST; device->local_config.int_params[AC_my] * NGHOST;
MPI_Request request_front[NUM_VTXBUF_HANDLES];
MPI_Status status_front[NUM_VTXBUF_HANDLES];
MPI_Request request_back[NUM_VTXBUF_HANDLES];
MPI_Status status_back[NUM_VTXBUF_HANDLES];
for (int i = 0; i < NUM_VTXBUF_HANDLES; ++i) {
{ // Front
// ...|ooooxxx|... -> xxx|ooooooo|...
const size_t src_idx = acVertexBufferIdx(0, 0, device->local_config.int_params[AC_nz],
device->local_config);
const size_t dst_idx = acVertexBufferIdx(0, 0, 0, device->local_config);
const int send_pid = (pid + 1) % num_processes;
MPI_Isend(&device->vba.in[i][src_idx], count, datatype, send_pid, i, MPI_COMM_WORLD,
&request_front[i]);
}
{ // Back
// ...|ooooooo|xxx <- ...|xxxoooo|...
const size_t src_idx = acVertexBufferIdx(0, 0, NGHOST, device->local_config);
const size_t dst_idx = acVertexBufferIdx(
0, 0, NGHOST + device->local_config.int_params[AC_nz], device->local_config);
const int send_pid = (pid + num_processes - 1) % num_processes;
MPI_Isend(&device->vba.in[i][src_idx], count, datatype, send_pid,
NUM_VTXBUF_HANDLES + i, MPI_COMM_WORLD, &request_back[i]);
}
}
for (int i = 0; i < NUM_VTXBUF_HANDLES; ++i) {
{ // Front
// ...|ooooxxx|... -> xxx|ooooooo|...
const size_t src_idx = acVertexBufferIdx(0, 0, device->local_config.int_params[AC_nz],
device->local_config);
const size_t dst_idx = acVertexBufferIdx(0, 0, 0, device->local_config);
const int recv_pid = (pid + num_processes - 1) % num_processes;
MPI_Recv(&device->vba.in[i][dst_idx], count, datatype, recv_pid, i, MPI_COMM_WORLD,
&status_front[i]);
}
{ // Back
// ...|ooooooo|xxx <- ...|xxxoooo|...
const size_t src_idx = acVertexBufferIdx(0, 0, NGHOST, device->local_config);
const size_t dst_idx = acVertexBufferIdx(
0, 0, NGHOST + device->local_config.int_params[AC_nz], device->local_config);
const int recv_pid = (pid + 1) % num_processes;
MPI_Recv(&device->vba.in[i][dst_idx], count, datatype, recv_pid, NUM_VTXBUF_HANDLES + i,
MPI_COMM_WORLD, &status_back[i]);
}
}
for (int i = 0; i < NUM_VTXBUF_HANDLES; ++i) {
MPI_Wait(&request_front[i], &status_front[i]);
MPI_Wait(&request_back[i], &status_back[i]);
}
/*
for (int i = 0; i < NUM_VTXBUF_HANDLES; ++i) { for (int i = 0; i < NUM_VTXBUF_HANDLES; ++i) {
{ // Front { // Front
// ...|ooooxxx|... -> xxx|ooooooo|... // ...|ooooxxx|... -> xxx|ooooooo|...
@@ -913,6 +965,7 @@ acDeviceCommunicateHalosMPI(const Device device)
MPI_Wait(&request, &status); MPI_Wait(&request, &status);
} }
} }
*/
return AC_SUCCESS; return AC_SUCCESS;
} }