public override void setThrottling()
{
#if DEBUG_NETUTIL
Console.Write("\n:: cycle {0} ::",
Simulator.CurrentRound);
#endif
//get the MPKI value
for (int i = 0; i < Config.N; i++)
{
prev_MPKI[i] = MPKI[i];
if (num_ins_last_epoch[i] == 0)
{
MPKI[i] = ((double)(L1misses[i] * 1000)) / (Simulator.stats.insns_persrc[i].Count);
}
else
{
if (Simulator.stats.insns_persrc[i].Count - num_ins_last_epoch[i] > 0)
{
MPKI[i] = ((double)(L1misses[i] * 1000)) / (Simulator.stats.insns_persrc[i].Count - num_ins_last_epoch[i]);
}
else if (Simulator.stats.insns_persrc[i].Count - num_ins_last_epoch[i] == 0)
{
MPKI[i] = 0;
}
else
{
throw new Exception("MPKI error!");
}
}
}
recordStats();
if (isThrottling)
{
double netutil = ((double)(Simulator.stats.netutil.Total - lastNetUtil) / (double)Config.throttle_sampling_period);
#if DEBUG_NETUTIL
Console.WriteLine("In throttle mode: avg netUtil = {0} thres at {1}",
netutil, Config.netutil_throttling_threshold);
#endif
/* TODO:
* 1.If the netutil remains high, lower the threshold value for each cluster
* to reduce the netutil further more and create a new pool/schedule for
* all the clusters. How to raise it back?
* Worst case: 1 app per cluster.
*
* 2.Find the difference b/w the current netutil and the threshold.
* Then increase the throttle rate for each cluster based on that difference.
*
* 3.maybe add stalling clusters?
* */
isThrottling = false;
//un-throttle the network
for (int i = 0; i < Config.N; i++)
{
setThrottleRate(i, false);
}
cluster_pool.removeAllClusters();
double diff = netutil - Config.netutil_throttling_threshold;
//Option1: adjust the mpki thresh for each cluster
//if netutil within range of 10% increase MPKI boundary for each cluster
if (Config.adaptive_cluster_mpki)
{
double new_MPKI_thresh = cluster_pool.clusterThreshold();
if (diff < 0.10)
{
new_MPKI_thresh += 10;
}
else if (diff > 0.2)
{
new_MPKI_thresh -= 20;
}
cluster_pool.changeThresh(new_MPKI_thresh);
}
//Option2: adjust the throttle rate
//
//
//Use alpha*total_MPKI+base to find the optimal netutil for performance
//0.5 is the baseline netutil threshold
//0.03 is calculated empricically using some base cases to find this number b/w total_mpki and target netutil
double total_mpki = 0.0;
for (int i = 0; i < Config.N; i++)
{
total_mpki += MPKI[i];
}
double target_netutil = (0.03 * total_mpki + 50) / 100;
//50% baseline
if (Config.alpha)
{
//within 2% range
if (netutil < (0.98 * target_netutil))
{
Config.RR_throttle_rate -= 0.02;
}
else if (netutil > (1.02 * target_netutil))
{
if (Config.RR_throttle_rate < 0.95)//max is 95%
{
Config.RR_throttle_rate += 0.01;
}
}
//if target is too high, only throttle max to 95% inj rate
if (target_netutil > 0.9)
{
Config.RR_throttle_rate = 0.95;
}
}
//Trying to force 60-70% netutil
if (Config.adaptive_rate)
{
if (diff < 0.1)
{
Config.RR_throttle_rate -= 0.02;
}
else if (diff > 0.2)
{
if (Config.RR_throttle_rate < 0.95)
{
Config.RR_throttle_rate += 0.01;
}
}
}
#if DEBUG_CLUSTER_RATE
Console.WriteLine("Netutil diff: {2}-{3}={1} New th rate:{0} New MPKI thresh: {6} Target netutil:{4} Total MPKI:{5}",
Config.RR_throttle_rate, diff,
netutil, Config.netutil_throttling_threshold, target_netutil, total_mpki, cluster_pool.clusterThreshold());
#endif
Simulator.stats.total_th_rate.Add(Config.RR_throttle_rate);
}
if (thresholdTrigger()) // an abstract fn() that trigger whether to start throttling or not
{
//determine if the node is high intensive by using MPKI
int total_high = 0;
double total_mpki = 0.0;
for (int i = 0; i < Config.N; i++)
{
total_mpki += MPKI[i];
if (MPKI[i] > Config.MPKI_high_node)
{
cluster_pool.addNewNode(i, MPKI[i]);
total_high++;
//TODO: add stats?
#if DEBUG
Console.Write("#ON#:Node {0} with MPKI {1} ", i, MPKI[i]);
#endif
}
else
{
#if DEBUG
Console.Write("@OFF@:Node {0} with MPKI {1} ", i, MPKI[i]);
#endif
}
}
Simulator.stats.total_sum_mpki.Add(total_mpki);
#if DEBUG
Console.WriteLine(")");
#endif
//if no node needs to be throttled, set throttling to false
isThrottling = (total_high > 0)?true:false;
#if DEBUG_CLUSTER
cluster_pool.printClusterPool();
#endif
}
}
