1 /* Copyright (c) 2010-2021. 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/Exception.hpp"
7 #include "simgrid/plugins/energy.h"
8 #include "simgrid/s4u/Engine.hpp"
9 #include "simgrid/s4u/Exec.hpp"
10 #include "src/include/surf/surf.hpp"
11 #include "src/kernel/activity/ExecImpl.hpp"
12 #include "src/plugins/vm/VirtualMachineImpl.hpp"
13 #include "src/surf/cpu_interface.hpp"
15 #include <boost/algorithm/string/classification.hpp>
16 #include <boost/algorithm/string/split.hpp>
18 SIMGRID_REGISTER_PLUGIN(host_energy, "Cpu energy consumption.", &sg_host_energy_plugin_init)
20 /** @defgroup plugin_host_energy plugin_host_energy Plugin Host Energy
24 This is the energy plugin, enabling to account not only for computation time, but also for the dissipated energy in the
26 To activate this plugin, first call :cpp:func:`sg_host_energy_plugin_init()` before your loading your platform, and
27 then use :cpp:func:`sg_host_get_consumed_energy()` to retrieve the consumption of a given host.
29 When the host is on, this energy consumption naturally depends on both the current CPU load and the host energy profile.
30 According to our measurements, the consumption is somehow linear in the amount of cores at full speed, with an
31 abnormality when all the cores are idle. The full details are in `our scientific paper
32 <https://hal.inria.fr/hal-01523608>`_ on that topic.
34 As a result, our energy model takes 4 parameters:
36 - ``Idle`` wattage (i.e., instantaneous consumption in Watt) when your host is up and running, but without anything to
38 - ``Epsilon`` wattage when all cores are at 0 or epsilon%, but not in Idle state.
39 - ``AllCores`` wattage when all cores of the host are at 100%.
40 - ``Off`` wattage when the host is turned off.
42 Here is an example of XML declaration:
46 <host id="HostA" speed="100.0Mf" core="4">
47 <prop id="wattage_per_state" value="100.0:120.0:200.0" />
48 <prop id="wattage_off" value="10" />
51 If only two values are given, ``Idle`` is used for the missing ``Epsilon`` value.
53 This example gives the following parameters: ``Off`` is 10 Watts; ``Idle`` is 100 Watts; ``Epsilon`` is 120 Watts and
54 ``AllCores`` is 200 Watts.
55 This is enough to compute the wattage as a function of the amount of loaded cores:
60 <tr><th>#Cores loaded</th><th>Wattage</th><th>Explanation</th></tr>
61 <tr><td>0 (idle)</td><td> 100 Watts </td><td> Idle value</td></tr>
62 <tr><td>0 (not idle)</td><td> 120 Watts</td><td> Epsilon value</td></tr>
63 <tr><td>1</td><td> 140 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
64 <tr><td>2</td><td> 160 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
65 <tr><td>3</td><td> 180 Watts</td><td> Linear extrapolation between Epsilon and AllCores</td></tr>
66 <tr><td>4</td><td> 200 Watts</td><td> AllCores value</td></tr>
72 <h4>How does DVFS interact with the host energy model?</h4>
74 If your host has several DVFS levels (several pstates), then you should give the energetic profile of each pstate level:
78 <host id="HostC" speed="100.0Mf,50.0Mf,20.0Mf" core="4">
79 <prop id="wattage_per_state"
80 value="95.0:120.0:200.0, 93.0:115.0:170.0, 90.0:110.0:150.0" />
81 <prop id="wattage_off" value="10" />
84 This encodes the following values:
89 <tr><th>pstate</th><th>Performance</th><th>Idle</th><th>Epsilon</th><th>AllCores</th></tr>
90 <tr><td>0</td><td>100 Mflop/s</td><td>95 Watts</td><td>120 Watts</td><td>200 Watts</td></tr>
91 <tr><td>1</td><td>50 Mflop/s</td><td>93 Watts</td><td>115 Watts</td><td>170 Watts</td></tr>
92 <tr><td>2</td><td>20 Mflop/s</td><td>90 Watts</td><td>110 Watts</td><td>150 Watts</td></tr>
95 To change the pstate of a given CPU, use the following functions:
96 :cpp:func:`MSG_host_get_nb_pstates()`, :cpp:func:`simgrid::s4u::Host::set_pstate()`,
97 :cpp:func:`MSG_host_get_power_peak_at()`.
101 <h4>How accurate are these models?</h4>
103 This model cannot be more accurate than your instantiation: with the default values, your result will not be accurate at
104 all. You can still get accurate energy prediction, provided that you carefully instantiate the model.
105 The first step is to ensure that your timing prediction match perfectly. But this is only the first step of the path,
106 and you really want to read `this paper <https://hal.inria.fr/hal-01523608>`_ to see all what you need to do
107 before you can get accurate energy predictions.
112 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
114 // Forwards declaration needed to make this function a friend (because friends have external linkage by default)
115 static void on_simulation_end();
127 PowerRange(double idle, double epsilon, double max) : idle_(idle), epsilon_(epsilon), max_(max), slope_(max-epsilon) {}
131 simgrid::s4u::Host* host_ = nullptr;
132 /*< List of (idle_power, epsilon_power, max_power) tuple corresponding to each cpu pstate */
133 std::vector<PowerRange> power_range_watts_list_;
135 /* We need to keep track of what pstate has been used, as we will sometimes be notified only *after* a pstate has been
136 * used (but we need to update the energy consumption with the old pstate!)
139 const int pstate_off_ = -1;
140 double watts_off_ = 0.0; /*< Consumption when the machine is turned off (shutdown) */
141 double total_energy_ = 0.0; /*< Total energy consumed by the host */
142 double last_updated_ = surf_get_clock(); /*< Timestamp of the last energy update event*/
144 /* Only used to split total energy into unused/used hosts.
145 * If you want to get this info for something else, rather use the host_load plugin
147 bool host_was_used_ = false;
149 void init_watts_range_list();
150 friend void ::on_simulation_end(); // For access to host_was_used_
153 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
155 explicit HostEnergy(simgrid::s4u::Host* ptr);
158 double get_current_watts_value();
159 double get_current_watts_value(double cpu_load) const;
160 double get_consumed_energy();
161 double get_watt_idle_at(int pstate) const;
162 double get_watt_min_at(int pstate) const;
163 double get_watt_max_at(int pstate) const;
164 double get_power_range_slope_at(int pstate) const;
165 double get_last_update_time() const { return last_updated_; }
169 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
171 /* Computes the consumption so far. Called lazily on need. */
172 void HostEnergy::update()
174 double start_time = last_updated_;
175 double finish_time = surf_get_clock();
177 // We may have start == finish if the past consumption was updated since the simcall was started
178 // for example if 2 actors requested to update the same host's consumption in a given scheduling round.
180 // Even in this case, we need to save the pstate for the next call (after this if),
181 // which may have changed since that recent update.
182 if (start_time < finish_time) {
183 double previous_energy = total_energy_;
185 double instantaneous_power_consumption = this->get_current_watts_value();
187 double energy_this_step = instantaneous_power_consumption * (finish_time - start_time);
189 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->getName()
191 total_energy_ = previous_energy + energy_this_step;
192 last_updated_ = finish_time;
194 XBT_DEBUG("[update_energy of %s] period=[%.8f-%.8f]; current speed=%.2E flop/s (pstate %i); total consumption "
195 "before: %.8f J -> added now: %.8f J",
196 host_->get_cname(), start_time, finish_time, host_->get_pstate_speed(pstate_), pstate_, previous_energy,
200 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
201 pstate_ = host_->is_on() ? host_->get_pstate() : pstate_off_;
204 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host_(ptr)
206 init_watts_range_list();
208 const char* off_power_str = host_->get_property("wattage_off");
209 if (off_power_str != nullptr) {
211 this->watts_off_ = std::stod(std::string(off_power_str));
212 } catch (const std::invalid_argument&) {
213 throw std::invalid_argument(std::string("Invalid value for property wattage_off of host ") + host_->get_cname() +
214 ": " + off_power_str);
217 /* watts_off is 0 by default */
220 HostEnergy::~HostEnergy() = default;
222 double HostEnergy::get_watt_idle_at(int pstate) const
224 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
226 return power_range_watts_list_[pstate].idle_;
229 double HostEnergy::get_watt_min_at(int pstate) const
231 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
233 return power_range_watts_list_[pstate].epsilon_;
236 double HostEnergy::get_watt_max_at(int pstate) const
238 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
240 return power_range_watts_list_[pstate].max_;
243 double HostEnergy::get_power_range_slope_at(int pstate) const
245 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
247 return power_range_watts_list_[pstate].slope_;
250 /** @brief Computes the power consumed by the host according to the current situation
252 * - If the host is off, that's the watts_off value
253 * - if it's on, take the current pstate and the current processor load into account */
254 double HostEnergy::get_current_watts_value()
256 if (this->pstate_ == pstate_off_) // The host is off (or was off at the beginning of this time interval)
257 return this->watts_off_;
259 double current_speed = host_->get_pstate_speed(this->pstate_);
263 if (current_speed <= 0)
264 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
265 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
268 cpu_load = host_->get_load() / current_speed;
270 /* Divide by the number of cores here to have a value between 0 and 1 */
271 cpu_load /= host_->get_core_count();
273 if (cpu_load > 1) // This condition is true for energy_ptask on 32 bits, even if cpu_load is displayed as 1.000000
274 cpu_load = 1; // That may be an harmless rounding error?
276 host_was_used_ = true;
279 return get_current_watts_value(cpu_load);
282 /** @brief Computes the power that the host would consume at the provided processor load
284 * Whether the host is ON or OFF is not taken into account.
286 double HostEnergy::get_current_watts_value(double cpu_load) const
288 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
291 /* Return watts_off if pstate == pstate_off (ie, if the host is off) */
292 if (this->pstate_ == pstate_off_) {
296 PowerRange power_range = power_range_watts_list_.at(this->pstate_);
297 double current_power;
302 * Something is going on, the host is not idle.
304 * The power consumption follows the regular model:
305 * P(cpu_load) = Pstatic + Pdynamic * cpu_load
306 * where Pstatic = power_range.epsilon_ and Pdynamic = power_range.slope_
307 * and the cpu_load is a value between 0 and 1.
309 current_power = power_range.epsilon_ + cpu_load * power_range.slope_;
313 /* The host is idle, take the dedicated value! */
314 current_power = power_range.idle_;
317 XBT_DEBUG("[get_current_watts] pstate=%i, epsilon_power=%f, max_power=%f, slope=%f", this->pstate_, power_range.epsilon_,
318 power_range.max_, power_range.slope_);
319 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
321 return current_power;
324 double HostEnergy::get_consumed_energy()
326 if (last_updated_ < surf_get_clock()) // We need to simcall this as it modifies the environment
327 simgrid::kernel::actor::simcall(std::bind(&HostEnergy::update, this));
329 return total_energy_;
332 void HostEnergy::init_watts_range_list()
334 const char* all_power_values_str = host_->get_property("wattage_per_state");
335 if (all_power_values_str == nullptr) {
336 /* If no power values are given, we assume it's 0 everywhere */
337 XBT_DEBUG("No energetic profiles given for host %s, using 0 W by default.", host_->get_cname());
338 for (int i = 0; i < host_->get_pstate_count(); ++i) {
339 PowerRange range(0,0,0);
340 power_range_watts_list_.push_back(range);
345 std::vector<std::string> all_power_values;
346 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
347 XBT_DEBUG("%s: power properties: %s", host_->get_cname(), all_power_values_str);
349 xbt_assert(all_power_values.size() == (unsigned)host_->get_pstate_count(),
350 "Invalid XML file. Found %zu energetic profiles for %d pstates", all_power_values.size(),
351 host_->get_pstate_count());
354 for (auto const& current_power_values_str : all_power_values) {
355 /* retrieve the power values associated with the pstate i */
356 std::vector<std::string> current_power_values;
357 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
359 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
360 "Power properties incorrectly defined for host %s."
361 "It should be 'Idle:AllCores' (or 'Idle:Epsilon:AllCores') power values.",
365 double epsilon_power;
368 auto msg_idle = xbt::string_printf("Invalid Idle value for pstate %d on host %s", i, host_->get_cname());
369 auto msg_epsilon = xbt::string_printf("Invalid Epsilon value for pstate %d on host %s", i, host_->get_cname());
370 auto msg_max = xbt::string_printf("Invalid AllCores value for pstate %d on host %s", i, host_->get_cname());
372 idle_power = xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle.c_str());
373 if (current_power_values.size() == 2) { // Case: Idle:AllCores
374 epsilon_power = xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle.c_str());
375 max_power = xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_max.c_str());
376 } else { // Case: Idle:Epsilon:AllCores
377 epsilon_power = xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_epsilon.c_str());
378 max_power = xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max.c_str());
381 XBT_DEBUG("Creating PowerRange for host %s. Idle:%f, Epsilon:%f, AllCores:%f.", host_->get_cname(), idle_power, epsilon_power, max_power);
383 PowerRange range(idle_power, epsilon_power, max_power);
384 power_range_watts_list_.push_back(range);
388 } // namespace plugin
389 } // namespace simgrid
391 using simgrid::plugin::HostEnergy;
393 /* **************************** events callback *************************** */
394 static void on_creation(simgrid::s4u::Host& host)
396 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
399 // TODO Trace: set to zero the energy variable associated to host->get_name()
401 host.extension_set(new HostEnergy(&host));
404 static void on_action_state_change(simgrid::kernel::resource::CpuAction const& action,
405 simgrid::kernel::resource::Action::State /*previous*/)
407 for (simgrid::kernel::resource::CpuImpl* const& cpu : action.cpus()) {
408 simgrid::s4u::Host* host = cpu->get_iface();
409 if (host != nullptr) {
410 // If it's a VM, take the corresponding PM
411 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
412 if (vm) // If it's a VM, take the corresponding PM
415 // Get the host_energy extension for the relevant host
416 auto* host_energy = host->extension<HostEnergy>();
418 if (host_energy->get_last_update_time() < surf_get_clock())
419 host_energy->update();
424 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
425 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
426 static void on_host_change(simgrid::s4u::Host const& host)
428 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
431 auto* host_energy = host.extension<HostEnergy>();
433 host_energy->update();
436 static void on_host_destruction(simgrid::s4u::Host const& host)
438 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
441 XBT_INFO("Energy consumption of host %s: %f Joules", host.get_cname(),
442 host.extension<HostEnergy>()->get_consumed_energy());
445 static void on_simulation_end()
447 double total_energy = 0.0; // Total energy consumption (whole platform)
448 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
449 for (simgrid::s4u::Host const* host : simgrid::s4u::Engine::get_instance()->get_all_hosts()) {
450 if (host && dynamic_cast<const simgrid::s4u::VirtualMachine*>(host) == nullptr) { // Ignore virtual machines
451 double energy = host->extension<HostEnergy>()->get_consumed_energy();
452 total_energy += energy;
453 if (host->extension<HostEnergy>()->host_was_used_)
454 used_hosts_energy += energy;
457 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)", total_energy,
458 used_hosts_energy, total_energy - used_hosts_energy);
461 /* **************************** Public interface *************************** */
463 /** @ingroup plugin_host_energy
464 * @brief Enable host energy plugin
465 * @details Enable energy plugin to get joules consumption of each cpu. Call this function before loading your platform.
467 void sg_host_energy_plugin_init()
469 if (HostEnergy::EXTENSION_ID.valid())
472 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
474 simgrid::s4u::Host::on_creation.connect(&on_creation);
475 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
476 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
477 simgrid::s4u::Host::on_destruction.connect(&on_host_destruction);
478 simgrid::s4u::Engine::on_simulation_end.connect(&on_simulation_end);
479 simgrid::kernel::resource::CpuAction::on_state_change.connect(&on_action_state_change);
480 // We may only have one actor on a node. If that actor executes something like
481 // compute -> recv -> compute
482 // the recv operation will not trigger a "CpuAction::on_state_change". This means
483 // that the next trigger would be the 2nd compute, hence ignoring the idle time
484 // during the recv call. By updating at the beginning of a compute, we can
485 // fix that. (If the cpu is not idle, this is not required.)
486 simgrid::s4u::Exec::on_start.connect([](simgrid::s4u::Exec const& activity) {
487 if (activity.get_host_number() == 1) { // We only run on one host
488 simgrid::s4u::Host* host = activity.get_host();
489 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
492 xbt_assert(host != nullptr);
493 host->extension<HostEnergy>()->update();
498 /** @ingroup plugin_host_energy
499 * @brief updates the consumption of all hosts
501 * After this call, sg_host_get_consumed_energy() will not interrupt your process
502 * (until after the next clock update).
504 void sg_host_energy_update_all()
506 simgrid::kernel::actor::simcall([]() {
507 std::vector<simgrid::s4u::Host*> list = simgrid::s4u::Engine::get_instance()->get_all_hosts();
508 for (auto const& host : list)
509 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) { // Ignore virtual machines
510 xbt_assert(host != nullptr);
511 host->extension<HostEnergy>()->update();
516 static void ensure_plugin_inited()
518 if (not HostEnergy::EXTENSION_ID.valid())
519 throw simgrid::xbt::InitializationError("The Energy plugin is not active. Please call sg_host_energy_plugin_init() "
520 "before calling any function related to that plugin.");
523 /** @ingroup plugin_host_energy
524 * @brief Returns the total energy consumed by the host so far (in Joules)
526 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
527 * The result is that the actor requesting this value will be interrupted,
528 * the value will be updated in kernel mode before returning the control to the requesting actor.
530 double sg_host_get_consumed_energy(const_sg_host_t host)
532 ensure_plugin_inited();
533 return host->extension<HostEnergy>()->get_consumed_energy();
536 /** @ingroup plugin_host_energy
537 * @brief Get the amount of watt dissipated when the host is idling
539 double sg_host_get_idle_consumption(const_sg_host_t host)
541 ensure_plugin_inited();
542 return host->extension<HostEnergy>()->get_watt_idle_at(0);
545 /** @ingroup plugin_host_energy
546 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
548 double sg_host_get_idle_consumption_at(const_sg_host_t host, int pstate)
550 ensure_plugin_inited();
551 return host->extension<HostEnergy>()->get_watt_idle_at(pstate);
554 /** @ingroup plugin_host_energy
555 * @brief Get the amount of watt dissipated at the given pstate when the host is at 0 or epsilon% CPU usage.
557 double sg_host_get_wattmin_at(const_sg_host_t host, int pstate)
559 ensure_plugin_inited();
560 return host->extension<HostEnergy>()->get_watt_min_at(pstate);
562 /** @ingroup plugin_host_energy
563 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
565 double sg_host_get_wattmax_at(const_sg_host_t host, int pstate)
567 ensure_plugin_inited();
568 return host->extension<HostEnergy>()->get_watt_max_at(pstate);
570 /** @ingroup plugin_host_energy
571 * @brief Returns the power slope at the given pstate
573 double sg_host_get_power_range_slope_at(const_sg_host_t host, int pstate)
575 ensure_plugin_inited();
576 return host->extension<HostEnergy>()->get_power_range_slope_at(pstate);
578 /** @ingroup plugin_host_energy
579 * @brief Returns the current consumption of the host
581 double sg_host_get_current_consumption(const_sg_host_t host)
583 ensure_plugin_inited();
584 return host->extension<HostEnergy>()->get_current_watts_value();