Making sampling interval and end time configurable, updating READMe file about sampling options

src/network-workloads/README_synthetic.txt

@@ -53,6 +53,12 @@ num_msgs: number of messages generated per terminal. Each message has a size of
 traffic: 1 for uniform random traffic, 2 for nearest group traffic and 3 for
 nearest neighbor traffic.
 
+sampling-interval: if time-stepped series sampling is turned on, this parameter
+can be used to configure the sampling interval.
+
+sampling-end-time: if time-stepped series sampling is turned on, this parameter
+can be used to configure end time.
+
 lp-io-dir: generates network traffic information on dragonfly terminals and
 routers. Here is information on individual files:
 

src/network-workloads/model-net-synthetic.c

@@ -34,6 +34,8 @@ static lp_io_handle io_handle;
 static unsigned int lp_io_use_suffix = 0;
 static int do_lp_io = 0;
 static int num_msgs = 20;
+static unsigned int sampling_interval = 800000;
+static unsigned int sampling_end_time = 1600000;
 
 typedef struct svr_msg svr_msg;
 typedef struct svr_state svr_state;
@@ -107,6 +109,8 @@ const tw_optdef app_opt [] =
         TWOPT_GROUP("Model net synthetic traffic " ),
     	TWOPT_UINT("traffic", traffic, "UNIFORM RANDOM=1, NEAREST NEIGHBOR=2 "),
     	TWOPT_UINT("num_messages", num_msgs, "Number of messages to be generated per terminal "),
+    	TWOPT_UINT("sampling-interval", sampling_interval, "the sampling interval "),
+    	TWOPT_UINT("sampling-end-time", sampling_end_time, "sampling end time "),
 	    TWOPT_STIME("arrival_time", arrival_time, "INTER-ARRIVAL TIME"),
         TWOPT_CHAR("lp-io-dir", lp_io_dir, "Where to place io output (unspecified -> no output"),
         TWOPT_UINT("lp-io-use-suffix", lp_io_use_suffix, "Whether to append uniq suffix to lp-io directory (default 0)"),
@@ -368,7 +372,7 @@ int main(
 
     /* 5 days of simulation time */
     g_tw_ts_end = s_to_ns(5 * 24 * 60 * 60);
-//    model_net_enable_sampling(800000, 1600000);
+    model_net_enable_sampling(sampling_interval, sampling_end_time);
 
     if(net_id != DRAGONFLY)
     {