Making tracing optional

clock-res/src/clockres.c

@@ -24,6 +24,7 @@ typedef struct thread_stat {
 typedef struct thread_param {
   int priority;
   int max_cycles;
+  int enable_tracing;
   uint64_t interval;
   uint64_t latency_threshold;
   thread_stat_t stat;
@@ -31,6 +32,7 @@ typedef struct thread_param {
 
 typedef struct main_param {
   int refresh_rate;
+  int enable_tracing;
 } main_param_t;
 
 static void process_options(int argc, char *argv[], thread_param_t *param,
@@ -60,17 +62,21 @@ static void *timerthread(void *p) {
   for (stat->nb_cycles = 0;; stat->nb_cycles++) {
     if (param->max_cycles && (stat->nb_cycles >= param->max_cycles)) break;
 
-    tracing(1);
+    if(param->enable_tracing)
+      tracing(1);
+
     clock_gettime(CLOCK_ID, &previous);
     clock_gettime(CLOCK_ID, &current);
-    tracing(0);
+
+    if(param->enable_tracing)
+      tracing(0);
 
     diff = calcdiff_ns(current, previous);
 
     stat->max_res = max(stat->max_res, diff);
     stat->min_res = min(stat->min_res, diff);
 
-    if( diff > param->latency_threshold ) break;
+    if( param->enable_tracing && (diff > param->latency_threshold) ) break;
 
     usleep(param->interval);
   }
@@ -89,10 +95,16 @@ int main(int argc, char *argv[]) {
   param.interval = 1000;
   param.max_cycles = 100000;
   param.priority = 99;
+  param.enable_tracing = 0;
+  main_param.enable_tracing = 0;
   main_param.refresh_rate = 10000;
 
   process_options(argc, argv, &param, &main_param);
-  setup_tracer();
+
+  if(main_param.enable_tracing) {
+    param.enable_tracing = 1;
+    setup_tracer();
+  }
 
   usleep(10000);
 
@@ -108,7 +120,7 @@ int main(int argc, char *argv[]) {
            param.stat.nb_cycles);
 
     if (param.max_cycles == param.stat.nb_cycles) break;
-    if (param.stat.max_res >= param.latency_threshold) break;
+    if (main_param.enable_tracing && (param.stat.max_res >= param.latency_threshold)) break;
   }
 
   tracing(0);
@@ -119,7 +131,7 @@ int main(int argc, char *argv[]) {
 static void process_options(int argc, char *argv[], thread_param_t *param,
                             main_param_t *main_param) {
   for (;;) {
-    int c = getopt(argc, argv, "l:p:i:r:b:");
+    int c = getopt(argc, argv, "l:p:i:r:b:f:");
 
     if (c == -1) break;
 
@@ -139,6 +151,9 @@ static void process_options(int argc, char *argv[], thread_param_t *param,
       case 'r':
         main_param->refresh_rate = atoi(optarg);
         break;
+      case 'f':
+        main_param->enable_tracing = 1;
+        break;
       default:
         exit(EXIT_FAILURE);
         break;