int do_wconsole(int argc, param *argv) {
if (argc != 1) return -1;
const char *line = argv[0].s;
while (*line) {
if (remote_msg(0x80000000 | *line)) return -1;
line++;
}
if (remote_msg(0x80000000 | '\r')) return -1;
return 0;
}
int main(int argc, char **argv) {
check_mpi_call( MPI_Init(&argc, &argv));
int mpi_rank;
int mpi_size;
check_mpi_call( MPI_Comm_size(MPI_COMM_WORLD, &mpi_size));
check_mpi_call( MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank));
const int mpi_root = 0;
auto hostname = get_hostname();
auto gpus = get_gpu_uuids();
auto num_gpus = gpus.size();
if(mpi_rank==mpi_root) {
std::cout << "GPU affinity test for " << mpi_size << " MPI ranks\n";
}
std::stringstream s;
s << "rank " << std::setw(6) << mpi_rank << " @ " << hostname;
if(num_gpus==1) {
s << " : GPU-" << gpus[0] << "\n";
}
else {
s << "\n";
for(auto i=0; i<num_gpus; ++i) {
s << " gpu " << std::setfill(' ') << std::setw(3) << i
<< " : GPU-" << gpus[i]
<< "\n";
}
}
auto message = s.str();
// add 1 for the terminating \0
int message_length = message.size() + 1;
std::vector<int> message_lengths(mpi_size);
check_mpi_call(
MPI_Gather( &message_length, 1, MPI_INT,
&message_lengths[0], 1, MPI_INT,
mpi_root, MPI_COMM_WORLD)
);
if(mpi_rank==mpi_root) {
std::cout << message;
for(auto i=1; i<mpi_size; ++i) {
std::vector<char> remote_msg(message_lengths[i]);
MPI_Status status;
check_mpi_call(
MPI_Recv( &remote_msg[0], message_lengths[i], MPI_CHAR,
i, i, MPI_COMM_WORLD, &status)
);
std::cout << &remote_msg[0];
}
}
else {
check_mpi_call(
MPI_Send( message.c_str(), message_length, MPI_CHAR,
mpi_root, mpi_rank, MPI_COMM_WORLD)
);
}
MPI_Finalize();
}
