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/s4u/Engine.hpp"
8 #include "src/include/surf/surf.hpp"
9 #include "src/plugins/vm/VirtualMachineImpl.hpp"
10 #include "src/surf/cpu_interface.hpp"
12 #include <boost/algorithm/string/classification.hpp>
13 #include <boost/algorithm/string/split.hpp>
15 SIMGRID_REGISTER_PLUGIN(host_energy, "Cpu energy consumption.", &sg_host_energy_plugin_init)
17 /** @addtogroup plugin_energy
19 This is the energy plugin, enabling to account not only for computation time, but also for the dissipated energy in the
21 To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(), and then use
22 MSG_host_get_consumed_energy() to retrieve the consumption of a given host.
24 When the host is on, this energy consumption naturally depends on both the current CPU load and the host energy profile.
25 According to our measurements, the consumption is somehow linear in the amount of cores at full speed, with an
26 abnormality when all the cores are idle. The full details are in
27 <a href="https://hal.inria.fr/hal-01523608">our scientific paper</a> on that topic.
29 As a result, our energy model takes 4 parameters:
31 - @b Idle: instantaneous consumption (in Watt) when your host is up and running, but without anything to do.
32 - @b OneCore: instantaneous consumption (in Watt) when only one core is active, at 100%.
33 - @b AllCores: instantaneous consumption (in Watt) when all cores of the host are at 100%.
34 - @b Off: instantaneous consumption (in Watt) when the host is turned off.
36 Here is an example of XML declaration:
39 <host id="HostA" power="100.0Mf" cores="4">
40 <prop id="watt_per_state" value="100.0:120.0:200.0" />
41 <prop id="watt_off" value="10" />
45 This example gives the following parameters: @b Off is 10 Watts; @b Idle is 100 Watts; @b OneCore is 120 Watts and @b
46 AllCores is 200 Watts.
47 This is enough to compute the consumption as a function of the amount of loaded cores:
50 <tr><th>@#Cores loaded</th><th>Consumption</th><th>Explanation</th></tr>
51 <tr><td>0</td><td> 100 Watts</td><td>Idle value</td></tr>
52 <tr><td>1</td><td> 120 Watts</td><td>OneCore value</td></tr>
53 <tr><td>2</td><td> 147 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
54 <tr><td>3</td><td> 173 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
55 <tr><td>4</td><td> 200 Watts</td><td>AllCores value</td></tr>
58 ### What if a given core is only at load 50%?
60 This is impossible in SimGrid because we recompute everything each time that the CPU starts or stops doing something.
61 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
62 the time, and our model holds.
64 ### What if the host has only one core?
66 In this case, the parameters @b OneCore and @b AllCores are obviously the same.
67 Actually, SimGrid expect an energetic profile formatted as 'Idle:Running' for mono-cores hosts.
68 If you insist on passing 3 parameters in this case, then you must have the same value for @b OneCore and @b AllCores.
71 <host id="HostC" power="100.0Mf" cores="1">
72 <prop id="watt_per_state" value="95.0:200.0" /> <!-- we may have used '95:200:200' instead -->
73 <prop id="watt_off" value="10" />
77 ### How does DVFS interact with the host energy model?
79 If your host has several DVFS levels (several pstates), then you should give the energetic profile of each pstate level:
82 <host id="HostC" power="100.0Mf,50.0Mf,20.0Mf" cores="4">
83 <prop id="watt_per_state" value="95.0:120.0:200.0, 93.0:115.0:170.0, 90.0:110.0:150.0" />
84 <prop id="watt_off" value="10" />
88 This encodes the following values
90 <tr><th>pstate</th><th>Performance</th><th>Idle</th><th>OneCore</th><th>AllCores</th></tr>
91 <tr><td>0</td><td>100 Mflop/s</td><td>95 Watts</td><td>120 Watts</td><td>200 Watts</td></tr>
92 <tr><td>1</td><td>50 Mflop/s</td><td>93 Watts</td><td>115 Watts</td><td>170 Watts</td></tr>
93 <tr><td>2</td><td>20 Mflop/s</td><td>90 Watts</td><td>110 Watts</td><td>150 Watts</td></tr>
96 To change the pstate of a given CPU, use the following functions:
97 #MSG_host_get_nb_pstates(), simgrid#s4u#Host#setPstate(), #MSG_host_get_power_peak_at().
99 ### How accurate are these models?
101 This model cannot be more accurate than your instantiation: with the default values, your result will not be accurate at
102 all. You can still get accurate energy prediction, provided that you carefully instantiate the model.
103 The first step is to ensure that your timing prediction match perfectly. But this is only the first step of the path,
104 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
105 before you can get accurate energy predictions.
108 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
110 // Forwards declaration needed to make this function a friend (because friends have external linkage by default)
111 static void on_simulation_end();
122 PowerRange(double idle, double min, double max) : idle_(idle), min_(min), max_(max) {}
126 friend void ::on_simulation_end(); // For access to host_was_used_
128 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
130 explicit HostEnergy(simgrid::s4u::Host* ptr);
133 double get_current_watts_value();
134 double get_current_watts_value(double cpu_load);
135 double get_consumed_energy();
136 double get_watt_min_at(int pstate);
137 double get_watt_max_at(int pstate);
141 void init_watts_range_list();
142 simgrid::s4u::Host* host_ = nullptr;
143 /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */
144 std::vector<PowerRange> power_range_watts_list_;
146 /* We need to keep track of what pstate has been used, as we will sometimes be notified only *after* a pstate has been
147 * used (but we need to update the energy consumption with the old pstate!)
150 const int pstate_off_ = -1;
152 /* Only used to split total energy into unused/used hosts.
153 * If you want to get this info for something else, rather use the host_load plugin
155 bool host_was_used_ = false;
157 double watts_off_ = 0.0; /*< Consumption when the machine is turned off (shutdown) */
158 double total_energy_ = 0.0; /*< Total energy consumed by the host */
159 double last_updated_; /*< Timestamp of the last energy update event*/
162 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
164 /* Computes the consumption so far. Called lazily on need. */
165 void HostEnergy::update()
167 double start_time = this->last_updated_;
168 double finish_time = surf_get_clock();
170 // We may have start == finish if the past consumption was updated since the simcall was started
171 // for example if 2 actors requested to update the same host's consumption in a given scheduling round.
173 // Even in this case, we need to save the pstate for the next call (after this if),
174 // which may have changed since that recent update.
175 if (start_time < finish_time) {
176 double previous_energy = this->total_energy_;
178 double instantaneous_consumption = this->get_current_watts_value();
180 double energy_this_step = instantaneous_consumption * (finish_time - start_time);
182 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->getName()
184 this->total_energy_ = previous_energy + energy_this_step;
185 this->last_updated_ = finish_time;
187 XBT_DEBUG("[update_energy of %s] period=[%.8f-%.8f]; current speed=%.2E flop/s (pstate %i); total consumption before: consumption change: %.8f J -> added now: %.8f J",
188 host_->get_cname(), start_time, finish_time, host_->pimpl_cpu->get_pstate_peak_speed(this->pstate_), this->pstate_, previous_energy,
192 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
193 this->pstate_ = host_->is_on() ? host_->get_pstate() : pstate_off_;
196 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host_(ptr), last_updated_(surf_get_clock())
198 init_watts_range_list();
200 const char* off_power_str = host_->get_property("watt_off");
201 if (off_power_str != nullptr) {
203 this->watts_off_ = std::stod(std::string(off_power_str));
204 } catch (std::invalid_argument& ia) {
205 throw std::invalid_argument(std::string("Invalid value for property watt_off of host ") + host_->get_cname() +
206 ": " + off_power_str);
209 /* watts_off is 0 by default */
212 HostEnergy::~HostEnergy() = default;
214 double HostEnergy::get_watt_min_at(int pstate)
216 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
218 return power_range_watts_list_[pstate].min_;
221 double HostEnergy::get_watt_max_at(int pstate)
223 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
225 return power_range_watts_list_[pstate].max_;
228 /** @brief Computes the power consumed by the host according to the current situation
230 * - If the host is off, that's the watts_off value
231 * - if it's on, take the current pstate and the current processor load into account */
232 double HostEnergy::get_current_watts_value()
234 if (this->pstate_ == pstate_off_) // The host is off (or was off at the beginning of this time interval)
235 return this->watts_off_;
237 double current_speed = host_->get_speed();
241 if (current_speed <= 0)
242 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
243 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
246 cpu_load = host_->pimpl_cpu->get_constraint()->get_usage() / current_speed;
248 /** Divide by the number of cores here **/
249 cpu_load /= host_->pimpl_cpu->get_core_count();
251 if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
254 host_was_used_ = true;
256 /* The problem with this model is that the load is always 0 or 1, never something less.
257 * Another possibility could be to model the total energy as
259 * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
261 * where X is the amount of idling cores, and Y the amount of computing cores.
263 return get_current_watts_value(cpu_load);
266 /** @brief Computes the power that the host would consume at the provided processor load
268 * Whether the host is ON or OFF is not taken into account.
270 double HostEnergy::get_current_watts_value(double cpu_load)
272 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
275 /* Return watts_off if pstate == pstate_off (ie, if the host is off) */
276 if (this->pstate_ == pstate_off_) {
280 /* min_power corresponds to the power consumed when only one core is active */
281 /* max_power is the power consumed at 100% cpu load */
282 auto range = power_range_watts_list_.at(this->pstate_);
283 double current_power = 0;
284 double min_power = 0;
285 double max_power = 0;
286 double power_slope = 0;
288 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
289 min_power = range.min_;
290 max_power = range.max_;
293 * The min_power states how much we consume when only one single
294 * core is working. This means that when cpu_load == 1/coreCount, then
295 * current_power == min_power.
297 * The maximum must be reached when all cores are working (but 1 core was
298 * already accounted for by min_power)
299 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
300 * (maxCpuLoad is by definition 1)
303 int coreCount = host_->get_core_count();
304 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
306 power_slope = (max_power - min_power) / (1 - coreReciprocal);
308 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
310 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
311 } else { /* Our machine is idle, take the dedicated value! */
312 current_power = range.idle_;
315 XBT_DEBUG("[get_current_watts] pstate=%i, min_power=%f, max_power=%f, slope=%f", this->pstate_, min_power, max_power, power_slope);
316 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
318 return current_power;
321 double HostEnergy::get_consumed_energy()
323 if (last_updated_ < surf_get_clock()) // We need to simcall this as it modifies the environment
324 simgrid::simix::simcall(std::bind(&HostEnergy::update, this));
326 return total_energy_;
329 void HostEnergy::init_watts_range_list()
331 const char* all_power_values_str = host_->get_property("watt_per_state");
332 if (all_power_values_str == nullptr)
335 std::vector<std::string> all_power_values;
336 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
337 XBT_DEBUG("%s: profile: %s, cores: %d", host_->get_cname(), all_power_values_str, host_->get_core_count());
340 for (auto const& current_power_values_str : all_power_values) {
341 /* retrieve the power values associated with the current pstate */
342 std::vector<std::string> current_power_values;
343 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
344 if (host_->get_core_count() == 1) {
345 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
346 "Power properties incorrectly defined for host %s."
347 "It should be 'Idle:FullSpeed' power values because you have one core only.",
349 if (current_power_values.size() == 2) {
350 // In this case, 1core == AllCores
351 current_power_values.push_back(current_power_values.at(1));
352 } else { // size == 3
353 current_power_values[2] = current_power_values.at(1);
354 static bool displayed_warning = false;
355 if (not displayed_warning) { // Otherwise we get in the worst case no_pstate*no_hosts warnings
356 XBT_WARN("Host %s is a single-core machine and part of the power profile is '%s'"
357 ", which is in the 'Idle:OneCore:AllCores' format."
358 " Since this is a single-core machine, AllCores and OneCore are identical."
359 " Here, only the value for 'OneCore' is used.", host_->get_cname(), current_power_values_str.c_str());
360 displayed_warning = true;
364 xbt_assert(current_power_values.size() == 3,
365 "Power properties incorrectly defined for host %s."
366 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
370 /* min_power corresponds to the idle power (cpu load = 0) */
371 /* max_power is the power consumed at 100% cpu load */
372 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host_->get_cname());
373 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host_->get_cname());
374 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host_->get_cname());
375 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
376 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
377 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
378 power_range_watts_list_.push_back(range);
385 } // namespace plugin
386 } // namespace simgrid
388 using simgrid::plugin::HostEnergy;
390 /* **************************** events callback *************************** */
391 static void on_creation(simgrid::s4u::Host& host)
393 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
396 // TODO Trace: set to zero the energy variable associated to host->getName()
398 host.extension_set(new HostEnergy(&host));
401 static void on_action_state_change(simgrid::surf::CpuAction* action,
402 simgrid::kernel::resource::Action::State /*previous*/)
404 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
405 simgrid::s4u::Host* host = cpu->get_host();
406 if (host != nullptr) {
408 // If it's a VM, take the corresponding PM
409 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
410 if (vm) // If it's a VM, take the corresponding PM
413 // Get the host_energy extension for the relevant host
414 HostEnergy* host_energy = host->extension<HostEnergy>();
416 if (host_energy->last_updated_ < surf_get_clock())
417 host_energy->update();
422 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
423 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
424 static void on_host_change(simgrid::s4u::Host& host)
426 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
429 HostEnergy* host_energy = host.extension<HostEnergy>();
431 host_energy->update();
434 static void on_host_destruction(simgrid::s4u::Host& host)
436 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
439 XBT_INFO("Energy consumption of host %s: %f Joules", host.get_cname(),
440 host.extension<HostEnergy>()->get_consumed_energy());
443 static void on_simulation_end()
445 std::vector<simgrid::s4u::Host*> hosts = simgrid::s4u::Engine::get_instance()->get_all_hosts();
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 (size_t i = 0; i < hosts.size(); i++) {
450 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(hosts[i]) == nullptr) { // Ignore virtual machines
452 double energy = hosts[i]->extension<HostEnergy>()->get_consumed_energy();
453 total_energy += energy;
454 if (hosts[i]->extension<HostEnergy>()->host_was_used_)
455 used_hosts_energy += energy;
458 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)", total_energy,
459 used_hosts_energy, total_energy - used_hosts_energy);
462 /* **************************** Public interface *************************** */
464 /** @ingroup plugin_energy
465 * @brief Enable host energy plugin
466 * @details Enable energy plugin to get joules consumption of each cpu. Call this function before #MSG_init().
468 void sg_host_energy_plugin_init()
470 if (HostEnergy::EXTENSION_ID.valid())
473 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
475 simgrid::s4u::Host::on_creation.connect(&on_creation);
476 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
477 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
478 simgrid::s4u::Host::on_destruction.connect(&on_host_destruction);
479 simgrid::s4u::on_simulation_end.connect(&on_simulation_end);
480 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
483 /** @ingroup plugin_energy
484 * @brief updates the consumption of all hosts
486 * After this call, sg_host_get_consumed_energy() will not interrupt your process
487 * (until after the next clock update).
489 void sg_host_energy_update_all()
491 simgrid::simix::simcall([]() {
492 std::vector<simgrid::s4u::Host*> list = simgrid::s4u::Engine::get_instance()->get_all_hosts();
493 for (auto const& host : list)
494 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) // Ignore virtual machines
495 host->extension<HostEnergy>()->update();
499 /** @ingroup plugin_energy
500 * @brief Returns the total energy consumed by the host so far (in Joules)
502 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
503 * The result is that the actor requesting this value will be interrupted,
504 * the value will be updated in kernel mode before returning the control to the requesting actor.
506 double sg_host_get_consumed_energy(sg_host_t host)
508 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
509 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
510 return host->extension<HostEnergy>()->get_consumed_energy();
513 /** @ingroup plugin_energy
514 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
516 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
518 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
519 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
520 return host->extension<HostEnergy>()->get_watt_min_at(pstate);
522 /** @ingroup plugin_energy
523 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
525 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
527 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
528 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
529 return host->extension<HostEnergy>()->get_watt_max_at(pstate);
532 /** @ingroup plugin_energy
533 * @brief Returns the current consumption of the host
535 double sg_host_get_current_consumption(sg_host_t host)
537 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
538 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
539 return host->extension<HostEnergy>()->get_current_watts_value();