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=[%.8f-%.8f]; current speed=%.2E flop/s (pstate %i); total consumption before: consumption change: %.8f J -> added now: %.8f J",
181 host_->get_cname(), start_time, finish_time, host_->pimpl_cpu->get_pstate_peak_speed(this->pstate_), this->pstate_, previous_energy,
185 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
186 this->pstate_ = host_->is_on() ? host_->get_pstate() : pstate_off_;
189 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host_(ptr), last_updated_(surf_get_clock())
191 init_watts_range_list();
193 const char* off_power_str = host_->get_property("watt_off");
194 if (off_power_str != nullptr) {
196 this->watts_off_ = std::stod(std::string(off_power_str));
197 } catch (std::invalid_argument& ia) {
198 throw std::invalid_argument(std::string("Invalid value for property watt_off of host ") + host_->get_cname() +
199 ": " + off_power_str);
202 /* watts_off is 0 by default */
205 HostEnergy::~HostEnergy() = default;
207 double HostEnergy::get_watt_min_at(int pstate)
209 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
211 return power_range_watts_list_[pstate].min_;
214 double HostEnergy::get_watt_max_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].max_;
221 /** @brief Computes the power consumed by the host according to the current situation
223 * - If the host is off, that's the watts_off value
224 * - if it's on, take the current pstate and the current processor load into account */
225 double HostEnergy::get_current_watts_value()
227 if (this->pstate_ == pstate_off_) // The host is off (or was off at the beginning of this time interval)
228 return this->watts_off_;
230 double current_speed = host_->get_speed();
234 if (current_speed <= 0)
235 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
236 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
239 cpu_load = host_->pimpl_cpu->get_constraint()->get_usage() / current_speed;
241 /** Divide by the number of cores here **/
242 cpu_load /= host_->pimpl_cpu->get_core_count();
244 if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
247 /* The problem with this model is that the load is always 0 or 1, never something less.
248 * Another possibility could be to model the total energy as
250 * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
252 * where X is the amount of idling cores, and Y the amount of computing cores.
254 return get_current_watts_value(cpu_load);
257 /** @brief Computes the power that the host would consume at the provided processor load
259 * Whether the host is ON or OFF is not taken into account.
261 double HostEnergy::get_current_watts_value(double cpu_load)
263 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
266 /* Return watts_off if pstate == pstate_off (ie, if the host is off) */
267 if (this->pstate_ == pstate_off_) {
271 /* min_power corresponds to the power consumed when only one core is active */
272 /* max_power is the power consumed at 100% cpu load */
273 auto range = power_range_watts_list_.at(this->pstate_);
274 double current_power = 0;
275 double min_power = 0;
276 double max_power = 0;
277 double power_slope = 0;
279 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
280 min_power = range.min_;
281 max_power = range.max_;
284 * The min_power states how much we consume when only one single
285 * core is working. This means that when cpu_load == 1/coreCount, then
286 * current_power == min_power.
288 * The maximum must be reached when all cores are working (but 1 core was
289 * already accounted for by min_power)
290 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
291 * (maxCpuLoad is by definition 1)
294 int coreCount = host_->get_core_count();
295 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
297 power_slope = (max_power - min_power) / (1 - coreReciprocal);
299 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
301 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
302 } else { /* Our machine is idle, take the dedicated value! */
303 current_power = range.idle_;
306 XBT_DEBUG("[get_current_watts] pstate=%i, min_power=%f, max_power=%f, slope=%f", this->pstate_, min_power, max_power, power_slope);
307 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
309 return current_power;
312 double HostEnergy::get_consumed_energy()
314 if (last_updated_ < surf_get_clock()) // We need to simcall this as it modifies the environment
315 simgrid::simix::simcall(std::bind(&HostEnergy::update, this));
317 return total_energy_;
320 void HostEnergy::init_watts_range_list()
322 const char* all_power_values_str = host_->get_property("watt_per_state");
323 if (all_power_values_str == nullptr)
326 std::vector<std::string> all_power_values;
327 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
328 XBT_DEBUG("%s: profile: %s, cores: %d", host_->get_cname(), all_power_values_str, host_->get_core_count());
331 for (auto const& current_power_values_str : all_power_values) {
332 /* retrieve the power values associated with the current pstate */
333 std::vector<std::string> current_power_values;
334 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
335 if (host_->get_core_count() == 1) {
336 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
337 "Power properties incorrectly defined for host %s."
338 "It should be 'Idle:FullSpeed' power values because you have one core only.",
340 if (current_power_values.size() == 2) {
341 // In this case, 1core == AllCores
342 current_power_values.push_back(current_power_values.at(1));
343 } else { // size == 3
344 current_power_values[2] = current_power_values.at(1);
345 static thread_local bool displayed_warning = false;
346 if (not displayed_warning) { // Otherwise we get in the worst case no_pstate*no_hosts warnings
347 XBT_WARN("Host %s is a single-core machine and part of the power profile is '%s'"
348 ", which is in the 'Idle:OneCore:AllCores' format."
349 " Since this is a single-core machine, AllCores and OneCore are identical."
350 " Here, only the value for 'OneCore' is used.", host_->get_cname(), current_power_values_str.c_str());
351 displayed_warning = true;
355 xbt_assert(current_power_values.size() == 3,
356 "Power properties incorrectly defined for host %s."
357 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
361 /* min_power corresponds to the idle power (cpu load = 0) */
362 /* max_power is the power consumed at 100% cpu load */
363 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host_->get_cname());
364 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host_->get_cname());
365 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host_->get_cname());
366 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
367 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
368 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
369 power_range_watts_list_.push_back(range);
376 } // namespace plugin
377 } // namespace simgrid
379 using simgrid::plugin::HostEnergy;
381 /* **************************** events callback *************************** */
382 static void on_creation(simgrid::s4u::Host& host)
384 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
387 // TODO Trace: set to zero the energy variable associated to host->getName()
389 host.extension_set(new HostEnergy(&host));
392 static void on_action_state_change(simgrid::surf::CpuAction* action,
393 simgrid::kernel::resource::Action::State /*previous*/)
395 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
396 simgrid::s4u::Host* host = cpu->get_host();
397 if (host != nullptr) {
399 // If it's a VM, take the corresponding PM
400 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
401 if (vm) // If it's a VM, take the corresponding PM
404 // Get the host_energy extension for the relevant host
405 HostEnergy* host_energy = host->extension<HostEnergy>();
407 if (host_energy->last_updated_ < surf_get_clock())
408 host_energy->update();
413 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
414 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
415 static void on_host_change(simgrid::s4u::Host& host)
417 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
420 HostEnergy* host_energy = host.extension<HostEnergy>();
422 host_energy->update();
425 static void on_host_destruction(simgrid::s4u::Host& host)
427 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
430 XBT_INFO("Energy consumption of host %s: %f Joules", host.get_cname(),
431 host.extension<HostEnergy>()->get_consumed_energy());
434 static void on_simulation_end()
436 std::vector<simgrid::s4u::Host*> hosts = simgrid::s4u::Engine::get_instance()->get_all_hosts();
438 double total_energy = 0.0; // Total energy consumption (whole platform)
439 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
440 for (size_t i = 0; i < hosts.size(); i++) {
441 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(hosts[i]) == nullptr) { // Ignore virtual machines
443 bool host_was_used = (sg_host_get_computed_flops(hosts[i]) != 0);
444 double energy = hosts[i]->extension<HostEnergy>()->get_consumed_energy();
445 total_energy += energy;
447 used_hosts_energy += energy;
450 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)", total_energy,
451 used_hosts_energy, total_energy - used_hosts_energy);
454 /* **************************** Public interface *************************** */
456 /** @ingroup plugin_energy
457 * @brief Enable host energy plugin
458 * @details Enable energy plugin to get joules consumption of each cpu. Call this function before #MSG_init().
460 void sg_host_energy_plugin_init()
462 if (HostEnergy::EXTENSION_ID.valid())
465 sg_host_load_plugin_init();
467 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
469 simgrid::s4u::Host::on_creation.connect(&on_creation);
470 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
471 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
472 simgrid::s4u::Host::on_destruction.connect(&on_host_destruction);
473 simgrid::s4u::on_simulation_end.connect(&on_simulation_end);
474 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
477 /** @ingroup plugin_energy
478 * @brief updates the consumption of all hosts
480 * After this call, sg_host_get_consumed_energy() will not interrupt your process
481 * (until after the next clock update).
483 void sg_host_energy_update_all()
485 simgrid::simix::simcall([]() {
486 std::vector<simgrid::s4u::Host*> list = simgrid::s4u::Engine::get_instance()->get_all_hosts();
487 for (auto const& host : list)
488 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) // Ignore virtual machines
489 host->extension<HostEnergy>()->update();
493 /** @ingroup plugin_energy
494 * @brief Returns the total energy consumed by the host so far (in Joules)
496 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
497 * The result is that the actor requesting this value will be interrupted,
498 * the value will be updated in kernel mode before returning the control to the requesting actor.
500 double sg_host_get_consumed_energy(sg_host_t host)
502 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
503 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
504 return host->extension<HostEnergy>()->get_consumed_energy();
507 /** @ingroup plugin_energy
508 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
510 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
512 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
513 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
514 return host->extension<HostEnergy>()->get_watt_min_at(pstate);
516 /** @ingroup plugin_energy
517 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
519 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
521 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
522 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
523 return host->extension<HostEnergy>()->get_watt_max_at(pstate);
526 /** @ingroup plugin_energy
527 * @brief Returns the current consumption of the host
529 double sg_host_get_current_consumption(sg_host_t host)
531 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
532 "The Energy plugin is not active. Please call sg_host_energy_plugin_init() during initialization.");
533 return host->extension<HostEnergy>()->get_current_watts_value();