1 /* Copyright (c) 2010-2018. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include "simgrid/plugins/energy.h"
7 #include "simgrid/plugins/load.h"
8 #include "simgrid/s4u/Engine.hpp"
9 #include "src/include/surf/surf.hpp"
10 #include "src/plugins/vm/VirtualMachineImpl.hpp"
11 #include "src/surf/cpu_interface.hpp"
13 #include <boost/algorithm/string/classification.hpp>
14 #include <boost/algorithm/string/split.hpp>
16 SIMGRID_REGISTER_PLUGIN(host_energy, "Cpu energy consumption.", &sg_host_energy_plugin_init)
18 /** @addtogroup plugin_energy
20 This is the energy plugin, enabling to account not only for computation time, but also for the dissipated energy in the
22 To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(), and then use
23 MSG_host_get_consumed_energy() to retrieve the consumption of a given host.
25 When the host is on, this energy consumption naturally depends on both the current CPU load and the host energy profile.
26 According to our measurements, the consumption is somehow linear in the amount of cores at full speed, with an
27 abnormality when all the cores are idle. The full details are in
28 <a href="https://hal.inria.fr/hal-01523608">our scientific paper</a> on that topic.
30 As a result, our energy model takes 4 parameters:
32 - \b Idle: instantaneous consumption (in Watt) when your host is up and running, but without anything to do.
33 - \b OneCore: instantaneous consumption (in Watt) when only one core is active, at 100%.
34 - \b AllCores: instantaneous consumption (in Watt) when all cores of the host are at 100%.
35 - \b Off: instantaneous consumption (in Watt) when the host is turned off.
37 Here is an example of XML declaration:
40 <host id="HostA" power="100.0Mf" cores="4">
41 <prop id="watt_per_state" value="100.0:120.0:200.0" />
42 <prop id="watt_off" value="10" />
46 This example gives the following parameters: \b Off is 10 Watts; \b Idle is 100 Watts; \b OneCore is 120 Watts and \b
47 AllCores is 200 Watts.
48 This is enough to compute the consumption as a function of the amount of loaded cores:
51 <tr><th>\#Cores loaded</th><th>Consumption</th><th>Explanation</th></tr>
52 <tr><td>0</td><td> 100 Watts</td><td>Idle value</td></tr>
53 <tr><td>1</td><td> 120 Watts</td><td>OneCore value</td></tr>
54 <tr><td>2</td><td> 147 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
55 <tr><td>3</td><td> 173 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
56 <tr><td>4</td><td> 200 Watts</td><td>AllCores value</td></tr>
59 ### What if a given core is only at load 50%?
61 This is impossible in SimGrid because we recompute everything each time that the CPU starts or stops doing something.
62 So if a core is at load 50% over a period, it means that it is at load 100% half of the time and at load 0% the rest of
63 the time, and our model holds.
65 ### What if the host has only one core?
67 In this case, the parameters \b OneCore and \b AllCores are obviously the same.
68 Actually, SimGrid expect an energetic profile formatted as 'Idle:Running' for mono-cores hosts.
69 If you insist on passing 3 parameters in this case, then you must have the same value for \b OneCore and \b AllCores.
72 <host id="HostC" power="100.0Mf" cores="1">
73 <prop id="watt_per_state" value="95.0:200.0" /> <!-- we may have used '95:200:200' instead -->
74 <prop id="watt_off" value="10" />
78 ### How does DVFS interact with the host energy model?
80 If your host has several DVFS levels (several pstates), then you should give the energetic profile of each pstate level:
83 <host id="HostC" power="100.0Mf,50.0Mf,20.0Mf" cores="4">
84 <prop id="watt_per_state" value="95.0:120.0:200.0, 93.0:115.0:170.0, 90.0:110.0:150.0" />
85 <prop id="watt_off" value="10" />
89 This encodes the following values
91 <tr><th>pstate</th><th>Performance</th><th>Idle</th><th>OneCore</th><th>AllCores</th></tr>
92 <tr><td>0</td><td>100 Mflop/s</td><td>95 Watts</td><td>120 Watts</td><td>200 Watts</td></tr>
93 <tr><td>1</td><td>50 Mflop/s</td><td>93 Watts</td><td>115 Watts</td><td>170 Watts</td></tr>
94 <tr><td>2</td><td>20 Mflop/s</td><td>90 Watts</td><td>110 Watts</td><td>150 Watts</td></tr>
97 To change the pstate of a given CPU, use the following functions:
98 #MSG_host_get_nb_pstates(), simgrid#s4u#Host#setPstate(), #MSG_host_get_power_peak_at().
100 ### How accurate are these models?
102 This model cannot be more accurate than your instantiation: with the default values, your result will not be accurate at
103 all. You can still get accurate energy prediction, provided that you carefully instantiate the model.
104 The first step is to ensure that your timing prediction match perfectly. But this is only the first step of the path,
105 and you really want to read <a href="https://hal.inria.fr/hal-01523608">this paper</a> to see all what you need to do
106 before you can get accurate energy predictions.
109 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
120 PowerRange(double idle, double min, double max) : idle_(idle), min_(min), max_(max) {}
125 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
127 explicit HostEnergy(simgrid::s4u::Host* ptr);
130 double get_current_watts_value();
131 double get_current_watts_value(double cpu_load);
132 double get_consumed_energy();
133 double get_watt_min_at(int pstate);
134 double get_watt_max_at(int pstate);
138 void init_watts_range_list();
139 simgrid::s4u::Host* host_ = nullptr;
140 /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */
141 std::vector<PowerRange> power_range_watts_list_;
143 /* We need to keep track of what pstate has been used, as we will sometimes be notified only *after* a pstate has been
144 * used (but we need to update the energy consumption with the old pstate!)
147 const int pstate_off_ = -1;
150 double watts_off_ = 0.0; /*< Consumption when the machine is turned off (shutdown) */
151 double total_energy_ = 0.0; /*< Total energy consumed by the host */
152 double last_updated_; /*< Timestamp of the last energy update event*/
155 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
157 /* Computes the consumption so far. Called lazily on need. */
158 void HostEnergy::update()
160 double start_time = this->last_updated_;
161 double finish_time = surf_get_clock();
163 // We may have start == finish if the past consumption was updated since the simcall was started
164 // for example if 2 actors requested to update the same host's consumption in a given scheduling round.
166 // Even in this case, we need to save the pstate for the next call (after this if),
167 // which may have changed since that recent update.
168 if (start_time < finish_time) {
169 double previous_energy = this->total_energy_;
171 double instantaneous_consumption = this->get_current_watts_value();
173 double energy_this_step = instantaneous_consumption * (finish_time - start_time);
175 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->getName()
177 this->total_energy_ = previous_energy + energy_this_step;
178 this->last_updated_ = finish_time;
180 XBT_DEBUG("[update_energy of %s] period=[%.2f-%.2f]; current power peak=%.0E flop/s; consumption change: %.2f J -> "
182 host_->get_cname(), start_time, finish_time, host_->pimpl_cpu->get_speed(1.0), previous_energy,
186 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
187 this->pstate_ = host_->is_on() ? host_->get_pstate() : pstate_off_;
190 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host_(ptr), last_updated_(surf_get_clock())
192 init_watts_range_list();
194 const char* off_power_str = host_->get_property("watt_off");
195 if (off_power_str != nullptr) {
197 this->watts_off_ = std::stod(std::string(off_power_str));
198 } catch (std::invalid_argument& ia) {
199 throw std::invalid_argument(std::string("Invalid value for property watt_off of host ") + host_->get_cname() +
200 ": " + off_power_str);
203 /* watts_off is 0 by default */
206 HostEnergy::~HostEnergy() = default;
208 double HostEnergy::get_watt_min_at(int pstate)
210 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
212 return power_range_watts_list_[pstate].min_;
215 double HostEnergy::get_watt_max_at(int pstate)
217 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
219 return power_range_watts_list_[pstate].max_;
222 /** @brief Computes the power consumed by the host according to the current situation
224 * - If the host is off, that's the watts_off value
225 * - if it's on, take the current pstate and the current processor load into account */
226 double HostEnergy::get_current_watts_value()
228 if (this->pstate_ == pstate_off_) // The host is off (or was off at the beginning of this time interval)
229 return this->watts_off_;
231 double current_speed = host_->get_speed();
235 if (current_speed <= 0)
236 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
237 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
240 cpu_load = host_->pimpl_cpu->get_constraint()->get_usage() / current_speed;
242 /** Divide by the number of cores here **/
243 cpu_load /= host_->pimpl_cpu->get_core_count();
245 if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
248 /* The problem with this model is that the load is always 0 or 1, never something less.
249 * Another possibility could be to model the total energy as
251 * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
253 * where X is the amount of idling cores, and Y the amount of computing cores.
255 return get_current_watts_value(cpu_load);
258 /** @brief Computes the power that the host would consume at the provided processor load
260 * Whether the host is ON or OFF is not taken into account.
262 double HostEnergy::get_current_watts_value(double cpu_load)
264 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
267 /* Return watts_off if pstate == pstate_off (ie, if the host is off) */
268 if (this->pstate_ == pstate_off_) {
272 /* min_power corresponds to the power consumed when only one core is active */
273 /* max_power is the power consumed at 100% cpu load */
274 auto range = power_range_watts_list_.at(this->pstate_);
275 double current_power = 0;
276 double min_power = 0;
277 double max_power = 0;
278 double power_slope = 0;
280 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
281 min_power = range.min_;
282 max_power = range.max_;
285 * The min_power states how much we consume when only one single
286 * core is working. This means that when cpu_load == 1/coreCount, then
287 * current_power == min_power.
289 * The maximum must be reached when all cores are working (but 1 core was
290 * already accounted for by min_power)
291 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
292 * (maxCpuLoad is by definition 1)
295 int coreCount = host_->get_core_count();
296 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
298 power_slope = (max_power - min_power) / (1 - coreReciprocal);
300 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
302 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
303 } else { /* Our machine is idle, take the dedicated value! */
304 current_power = range.idle_;
307 XBT_DEBUG("[get_current_watts] min_power=%f, max_power=%f, slope=%f", min_power, max_power, power_slope);
308 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
310 return current_power;
313 double HostEnergy::get_consumed_energy()
315 if (last_updated_ < surf_get_clock()) // We need to simcall this as it modifies the environment
316 simgrid::simix::simcall(std::bind(&HostEnergy::update, this));
318 return total_energy_;
321 void HostEnergy::init_watts_range_list()
323 const char* all_power_values_str = host_->get_property("watt_per_state");
324 if (all_power_values_str == nullptr)
327 std::vector<std::string> all_power_values;
328 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
329 XBT_DEBUG("%s: profile: %s, cores: %d", host_->get_cname(), all_power_values_str, host_->get_core_count());
332 for (auto const& current_power_values_str : all_power_values) {
333 /* retrieve the power values associated with the current pstate */
334 std::vector<std::string> current_power_values;
335 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
336 if (host_->get_core_count() == 1) {
337 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
338 "Power properties incorrectly defined for host %s."
339 "It should be 'Idle:FullSpeed' power values because you have one core only.",
341 if (current_power_values.size() == 2) {
342 // In this case, 1core == AllCores
343 current_power_values.push_back(current_power_values.at(1));
344 } else { // size == 3
345 xbt_assert((current_power_values.at(1)) == (current_power_values.at(2)),
346 "Power properties incorrectly defined for host %s.\n"
347 "The energy profile of mono-cores should be formatted as 'Idle:FullSpeed' only.\n"
348 "If you go for a 'Idle:OneCore:AllCores' power profile on mono-cores, then OneCore and AllCores "
353 xbt_assert(current_power_values.size() == 3,
354 "Power properties incorrectly defined for host %s."
355 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
359 /* min_power corresponds to the idle power (cpu load = 0) */
360 /* max_power is the power consumed at 100% cpu load */
361 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host_->get_cname());
362 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host_->get_cname());
363 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host_->get_cname());
364 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
365 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
366 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
367 power_range_watts_list_.push_back(range);
374 } // namespace plugin
375 } // namespace simgrid
377 using simgrid::plugin::HostEnergy;
379 /* **************************** events callback *************************** */
380 static void on_creation(simgrid::s4u::Host& host)
382 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
385 // TODO Trace: set to zero the energy variable associated to host->getName()
387 host.extension_set(new HostEnergy(&host));
390 static void on_action_state_change(simgrid::surf::CpuAction* action,
391 simgrid::kernel::resource::Action::State /*previous*/)
393 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
394 simgrid::s4u::Host* host = cpu->get_host();
395 if (host != nullptr) {
397 // If it's a VM, take the corresponding PM
398 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
399 if (vm) // If it's a VM, take the corresponding PM
402 // Get the host_energy extension for the relevant host
403 HostEnergy* host_energy = host->extension<HostEnergy>();
405 if (host_energy->last_updated_ < surf_get_clock())
406 host_energy->update();
411 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
412 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
413 static void on_host_change(simgrid::s4u::Host& host)
415 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
418 HostEnergy* host_energy = host.extension<HostEnergy>();
420 host_energy->update();
423 static void on_host_destruction(simgrid::s4u::Host& host)
425 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
428 XBT_INFO("Energy consumption of host %s: %f Joules", host.get_cname(),
429 host.extension<HostEnergy>()->get_consumed_energy());
432 static void on_simulation_end()
434 std::vector<simgrid::s4u::Host*> hosts = simgrid::s4u::Engine::get_instance()->get_all_hosts();
436 double total_energy = 0.0; // Total energy consumption (whole platform)
437 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
438 for (size_t i = 0; i < hosts.size(); i++) {
439 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(hosts[i]) == nullptr) { // Ignore virtual machines
441 bool host_was_used = (sg_host_get_computed_flops(hosts[i]) != 0);
442 double energy = hosts[i]->extension<HostEnergy>()->get_consumed_energy();
443 total_energy += energy;
445 used_hosts_energy += energy;
448 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)", total_energy,
449 used_hosts_energy, total_energy - used_hosts_energy);
452 /* **************************** Public interface *************************** */
454 /** \ingroup plugin_energy
455 * \brief Enable host energy plugin
456 * \details Enable energy plugin to get joules consumption of each cpu. Call this function before #MSG_init().
458 void sg_host_energy_plugin_init()
460 if (HostEnergy::EXTENSION_ID.valid())
463 sg_host_load_plugin_init();
465 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
467 simgrid::s4u::Host::on_creation.connect(&on_creation);
468 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
469 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
470 simgrid::s4u::Host::on_destruction.connect(&on_host_destruction);
471 simgrid::s4u::on_simulation_end.connect(&on_simulation_end);
472 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
475 /** @ingroup plugin_energy
476 * @brief updates the consumption of all hosts
478 * After this call, sg_host_get_consumed_energy() will not interrupt your process
479 * (until after the next clock update).
481 void sg_host_energy_update_all()
483 simgrid::simix::simcall([]() {
484 std::vector<simgrid::s4u::Host*> list = simgrid::s4u::Engine::get_instance()->get_all_hosts();
485 for (auto const& host : list)
486 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) // Ignore virtual machines
487 host->extension<HostEnergy>()->update();
491 /** @ingroup plugin_energy
492 * @brief Returns the total energy consumed by the host so far (in Joules)
494 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
495 * The result is that the actor requesting this value will be interrupted,
496 * the value will be updated in kernel mode before returning the control to the requesting actor.
498 double sg_host_get_consumed_energy(sg_host_t host)
500 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
501 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
502 return host->extension<HostEnergy>()->get_consumed_energy();
505 /** @ingroup plugin_energy
506 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
508 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
510 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
511 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
512 return host->extension<HostEnergy>()->get_watt_min_at(pstate);
514 /** @ingroup plugin_energy
515 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
517 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
519 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
520 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
521 return host->extension<HostEnergy>()->get_watt_max_at(pstate);
524 /** @ingroup plugin_energy
525 * @brief Returns the current consumption of the host
527 double sg_host_get_current_consumption(sg_host_t host)
529 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
530 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
531 return host->extension<HostEnergy>()->get_current_watts_value();