are at 200 Watts, 170 Watts, and 150 Watts respectively.
To change the pstate of a given CPU, use the following functions:
-#MSG_host_get_nb_pstates(), simgrid#s4u#Host#set_pstate(), #MSG_host_get_power_peak_at().
+#MSG_host_get_nb_pstates(), simgrid#s4u#Host#setPstate(), #MSG_host_get_power_peak_at().
To simulate the energy-related elements, first call the simgrid#energy#sg_energy_plugin_init() before your #MSG_init(),
and then use the following function to retrieve the consumption of a given host: MSG_host_get_consumed_energy().
double start_time = this->last_updated;
double finish_time = surf_get_clock();
double cpu_load;
- if (surf_host->cpu_->speed_.peak <= 0)
+ if (surf_host->cpu_->getPstateSpeedCurrent() <= 0)
// Some users declare a pstate of speed 0 flops (e.g., to model boot time).
// We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
cpu_load = 1;
else
- cpu_load = lmm_constraint_get_usage(surf_host->cpu_->getConstraint()) / surf_host->cpu_->speed_.peak;
+ cpu_load = lmm_constraint_get_usage(surf_host->cpu_->getConstraint()) / surf_host->cpu_->getPstateSpeedCurrent();
- if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not mores
+ /** Divide by the number of cores here **/
+ cpu_load /= surf_host->cpu_->getCoreCount();
+
+ if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
cpu_load = 1;
+ /* The problem with this model is that the load is always 0 or 1, never something less.
+ * Another possibility could be to model the total energy as
+ *
+ * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
+ *
+ * where X is the amount of ideling cores, and Y the amount of computing cores.
+ */
+
double previous_energy = this->total_energy;
double instantaneous_consumption;
double HostEnergy::getWattMinAt(int pstate)
{
xbt_assert(!power_range_watts_list.empty(), "No power range properties specified for host %s", host->name().c_str());
- return power_range_watts_list[pstate].first;
+ return power_range_watts_list[pstate].min;
}
double HostEnergy::getWattMaxAt(int pstate)
{
xbt_assert(!power_range_watts_list.empty(), "No power range properties specified for host %s", host->name().c_str());
- return power_range_watts_list[pstate].second;
+ return power_range_watts_list[pstate].max;
}
/** @brief Computes the power consumed by the host according to the current pstate and processor load */
/* min_power corresponds to the idle power (cpu load = 0) */
/* max_power is the power consumed at 100% cpu load */
- auto range = power_range_watts_list.at(host->pstate());
- double min_power = range.first;
- double max_power = range.second;
- double power_slope = max_power - min_power;
- double current_power = min_power + cpu_load * power_slope;
+ auto range = power_range_watts_list.at(host->pstate());
+ double current_power = 0;
+ double min_power = 0;
+ double max_power = 0;
+ double power_slope = 0;
+
+ if (cpu_load != 0) { /* Something is going on, the machine is not idle */
+ double min_power = range.min;
+ double max_power = range.max;
+ double power_slope = max_power - min_power;
+ current_power = min_power + cpu_load * power_slope;
+ }
+ else { /* Our machine is idle, take the dedicated value! */
+ current_power = range.idle;
+ }
XBT_DEBUG("[get_current_watts] min_power=%f, max_power=%f, slope=%f", min_power, max_power, power_slope);
XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
/* min_power corresponds to the idle power (cpu load = 0) */
/* max_power is the power consumed at 100% cpu load */
+ char *msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host->name().c_str());
char *msg_min = bprintf("Invalid min value for pstate %d on host %s: %%s", i, host->name().c_str());
- char *msg_max = bprintf("Invalid min value for pstate %d on host %s: %%s", i, host->name().c_str());
- power_range_watts_list.push_back(power_range(
- xbt_str_parse_double(xbt_dynar_get_as(current_power_values, 0, char*), msg_min),
- xbt_str_parse_double(xbt_dynar_get_as(current_power_values, 1, char*), msg_max)
- ));
+ char *msg_max = bprintf("Invalid max value for pstate %d on host %s: %%s", i, host->name().c_str());
+ PowerRange range(
+ xbt_str_parse_double(xbt_dynar_get_as(current_power_values, 0, char*), msg_idle),
+ xbt_str_parse_double(xbt_dynar_get_as(current_power_values, 1, char*), msg_min),
+ xbt_str_parse_double(xbt_dynar_get_as(current_power_values, 2, char*), msg_max)
+ );
+ power_range_watts_list.push_back(range);
xbt_free(msg_min);
xbt_free(msg_max);
