updated readme ; workload_type checking improvement

src/network-workload/README

@@ -3,7 +3,7 @@
 
 3- To run the program with 16 MPI ranks do:
 
-mpirun -np 8 ./codes-nw-test --sync=3 --total_nw_lps=16 --offset_file="offsets" --workload_file="scala-trace-data"
+mpirun -np 8 ./codes-nw-test --sync=3 --workload_type=scalatrace --total_nw_lps=16 --offset_file="offsets" --workload_file="scala-trace-data"
 
 The total_nw_lps is equal to the number of MPI ranks on which the data was recorded for scala-trace. In this case,
 total_nw_lps = 16 as the scala-trace data was recorded on 16 MPI ranks.

src/network-workload/codes-nw-test.c

@@ -66,6 +66,10 @@ void nw_test_init(nw_state* s, tw_lp* lp)
        return;
 #endif
    }
+   else{
+        tw_error(TW_LOC, "unsupported option: %s\n", workload_type);
+        return;
+   }
    wrkld_id = codes_nw_workload_load(wtype, params, (int)lp->gid);
    
    tw_event *e;