for (i = 0; i < extra->num_processes; i++)
fprintf(trace_file, "%d ", extra->recvcounts[i]);
fprintf(trace_file, "%s %s \n", extra->datatype1, extra->datatype2);
break;
case TRACING_REDUCE_SCATTER: // rank reducescatter [recvcounts] comp_size (sendtype)
for (i = 0; i < extra->num_processes; i++)
fprintf(trace_file, "%d ", extra->recvcounts[i]);
fprintf(trace_file, "%s %s \n", extra->datatype1, extra->datatype2);
break;
case TRACING_REDUCE_SCATTER: // rank reducescatter [recvcounts] comp_size (sendtype)