Precalculate the CPU frequency and then use that when synchronizing time,...

Precalculate the CPU frequency and then use that when synchronizing time, helps somewhat but we still have variance between nodes

swiftmpirdmaonestepsim.c

@@ -769,9 +769,10 @@ int main(int argc, char *argv[]) {
   if (myrank == 0) message("All RDMA servers are started");
 
   /* Reset time as previous can be thought of as setup costs? */
-  MPI_Barrier(MPI_COMM_WORLD);  // Vital...
+  long long freq = clocks_get_cpufreq();
+  MPI_Barrier(MPI_COMM_WORLD);  // Vital... but not accurate XXX
   if (myrank == 0) message("All synchronized, restarting time.");
-  clocks_set_cpufreq(0);
+  clocks_set_cpufreq(freq);
 
   /* Now we have a thread per rank to send the messages. */
   pthread_t sendthread[nr_ranks];

swiftmpirdmastepsim.c

@@ -541,8 +541,10 @@ int main(int argc, char *argv[]) {
   for (int k = 0; k < nr_ranks; k++) starting[k] = 1;
 
   /* Time to start time. Try to make it synchronous across the ranks. */
-  MPI_Barrier(MPI_COMM_WORLD);
   clocks_set_cpufreq(0);
+  long long freq = clocks_get_cpufreq();
+  MPI_Barrier(MPI_COMM_WORLD);
+  clocks_set_cpufreq(freq);
   if (myrank == 0) {
     message("Start of MPI tests");
     message("==================");
@@ -578,8 +580,8 @@ int main(int argc, char *argv[]) {
 
   /* Reset time as previous can be thought of as setup costs? */
   MPI_Barrier(MPI_COMM_WORLD);  // Vital...
+  clocks_set_cpufreq(freq);
   message("All synchronized");
-  clocks_set_cpufreq(0);
 
   /* Now we have a thread per rank to send the messages. */
   pthread_t sendthread[nr_ranks];

swiftmpistepsim.c

@@ -490,8 +490,10 @@ int main(int argc, char *argv[]) {
   pick_logs();
 
   /* Time to start time. Try to make it synchronous across the ranks. */
-  MPI_Barrier(MPI_COMM_WORLD);
   clocks_set_cpufreq(0);
+  long long freq = clocks_get_cpufreq();
+  MPI_Barrier(MPI_COMM_WORLD);
+  clocks_set_cpufreq(freq);
   if (myrank == 0) {
     message("Start of MPI tests");
     message("==================");