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) {
210 off_power_str = host_->get_property("watt_off");
212 static bool warned = false;
213 if (off_power_str != nullptr && not warned) {
215 XBT_WARN("Please use 'wattage_off' instead of 'watt_off' to define the idle wattage of hosts in your XML.");
218 if (off_power_str != nullptr) {
220 this->watts_off_ = std::stod(std::string(off_power_str));
221 } catch (const std::invalid_argument&) {
222 throw std::invalid_argument(std::string("Invalid value for property wattage_off of host ") + host_->get_cname() +
223 ": " + off_power_str);
226 /* watts_off is 0 by default */
229 HostEnergy::~HostEnergy() = default;
231 double HostEnergy::get_watt_idle_at(int pstate) const
233 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
235 return power_range_watts_list_[pstate].idle_;
238 double HostEnergy::get_watt_min_at(int pstate) const
240 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
242 return power_range_watts_list_[pstate].epsilon_;
245 double HostEnergy::get_watt_max_at(int pstate) const
247 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
249 return power_range_watts_list_[pstate].max_;
252 double HostEnergy::get_power_range_slope_at(int pstate) const
254 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
256 return power_range_watts_list_[pstate].slope_;
259 /** @brief Computes the power consumed by the host according to the current situation
261 * - If the host is off, that's the watts_off value
262 * - if it's on, take the current pstate and the current processor load into account */
263 double HostEnergy::get_current_watts_value()
265 if (this->pstate_ == pstate_off_) // The host is off (or was off at the beginning of this time interval)
266 return this->watts_off_;
268 double current_speed = host_->get_pstate_speed(this->pstate_);
272 if (current_speed <= 0)
273 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
274 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
277 cpu_load = host_->get_load() / current_speed;
279 /* Divide by the number of cores here to have a value between 0 and 1 */
280 cpu_load /= host_->get_core_count();
282 if (cpu_load > 1) // This condition is true for energy_ptask on 32 bits, even if cpu_load is displayed as 1.000000
283 cpu_load = 1; // That may be an harmless rounding error?
285 host_was_used_ = true;
288 return get_current_watts_value(cpu_load);
291 /** @brief Computes the power that the host would consume at the provided processor load
293 * Whether the host is ON or OFF is not taken into account.
295 double HostEnergy::get_current_watts_value(double cpu_load) const
297 xbt_assert(not power_range_watts_list_.empty(), "No power range properties specified for host %s",
300 /* Return watts_off if pstate == pstate_off (ie, if the host is off) */
301 if (this->pstate_ == pstate_off_) {
305 PowerRange power_range = power_range_watts_list_.at(this->pstate_);
306 double current_power;
311 * Something is going on, the host is not idle.
313 * The power consumption follows the regular model:
314 * P(cpu_load) = Pstatic + Pdynamic * cpu_load
315 * where Pstatic = power_range.epsilon_ and Pdynamic = power_range.slope_
316 * and the cpu_load is a value between 0 and 1.
318 current_power = power_range.epsilon_ + cpu_load * power_range.slope_;
322 /* The host is idle, take the dedicated value! */
323 current_power = power_range.idle_;
326 XBT_DEBUG("[get_current_watts] pstate=%i, epsilon_power=%f, max_power=%f, slope=%f", this->pstate_, power_range.epsilon_,
327 power_range.max_, power_range.slope_);
328 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
330 return current_power;
333 double HostEnergy::get_consumed_energy()
335 if (last_updated_ < surf_get_clock()) // We need to simcall this as it modifies the environment
336 simgrid::kernel::actor::simcall(std::bind(&HostEnergy::update, this));
338 return total_energy_;
341 void HostEnergy::init_watts_range_list()
343 const char* old_prop = host_->get_property("watt_per_state");
344 if (old_prop != nullptr) {
345 std::vector<std::string> all_power_values;
346 boost::split(all_power_values, old_prop, boost::is_any_of(","));
348 xbt_assert(all_power_values.size() == (unsigned)host_->get_pstate_count(),
349 "Invalid XML file. Found %zu energetic profiles for %d pstates", all_power_values.size(),
350 host_->get_pstate_count());
352 // XBT_ATTRIB_DEPRECATED_v328: putting this macro name here so that we find it during the deprecation cleanups
353 std::string msg = "DEPRECATION WARNING: Property 'watt_per_state' will only work until v3.28.\n";
354 msg += std::string("The old syntax 'Idle:OneCore:AllCores' must be converted into 'Idle:Epsilon:AllCores' to "
355 "properly model the consumption of non-whole tasks on mono-core hosts. Here are the values to "
357 host_->get_cname() + "' in your XML file:\n";
358 msg += " <prop id=\"wattage_per_state\" value=\"";
359 for (auto const& current_power_values_str : all_power_values) {
360 std::vector<std::string> current_power_values;
361 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
362 double p_idle = xbt_str_parse_double((current_power_values.at(0)).c_str(),
363 "Invalid obsolete XML file. Fix your watt_per_state property.");
367 if (current_power_values.size() == 3) {
368 double p_one_core = xbt_str_parse_double((current_power_values.at(1)).c_str(),
369 "Invalid obsolete XML file. Fix your watt_per_state property.");
370 p_full = xbt_str_parse_double((current_power_values.at(2)).c_str(),
371 "Invalid obsolete XML file. Fix your watt_per_state property.");
372 if (host_->get_core_count() == 1) {
375 p_epsilon = p_one_core - ((p_full - p_one_core) / (host_->get_core_count() - 1));
377 } else { // consumption given with idle and full only
378 p_full = xbt_str_parse_double((current_power_values.at(1)).c_str(),
379 "Invalid obsolete XML file. Fix your watt_per_state property.");
380 if (host_->get_core_count() == 1) {
387 PowerRange range(p_idle, p_epsilon, p_full);
388 power_range_watts_list_.push_back(range);
390 msg += std::to_string(p_idle) + ":" + std::to_string(p_epsilon) + ":" + std::to_string(p_full);
393 msg.pop_back(); // Remove the extraneous ','
395 XBT_WARN("%s", msg.c_str());
399 const char* all_power_values_str = host_->get_property("wattage_per_state");
400 if (all_power_values_str == nullptr) {
401 /* If no power values are given, we assume it's 0 everywhere */
402 XBT_DEBUG("No energetic profiles given for host %s, using 0 W by default.", host_->get_cname());
403 for (int i = 0; i < host_->get_pstate_count(); ++i) {
404 PowerRange range(0,0,0);
405 power_range_watts_list_.push_back(range);
410 std::vector<std::string> all_power_values;
411 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
412 XBT_DEBUG("%s: power properties: %s", host_->get_cname(), all_power_values_str);
414 xbt_assert(all_power_values.size() == (unsigned)host_->get_pstate_count(),
415 "Invalid XML file. Found %zu energetic profiles for %d pstates", all_power_values.size(),
416 host_->get_pstate_count());
419 for (auto const& current_power_values_str : all_power_values) {
420 /* retrieve the power values associated with the pstate i */
421 std::vector<std::string> current_power_values;
422 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
424 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
425 "Power properties incorrectly defined for host %s."
426 "It should be 'Idle:AllCores' (or 'Idle:Epsilon:AllCores') power values.",
430 double epsilon_power;
433 char* msg_idle = bprintf("Invalid Idle value for pstate %d on host %s: %%s", i, host_->get_cname());
434 char* msg_epsilon = bprintf("Invalid Epsilon value for pstate %d on host %s: %%s", i, host_->get_cname());
435 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host_->get_cname());
437 idle_power = xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle);
438 if (current_power_values.size() == 2) { // Case: Idle:AllCores
439 epsilon_power = xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle);
440 max_power = xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_max);
441 } else { // Case: Idle:Epsilon:AllCores
442 epsilon_power = xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_epsilon);
443 max_power = xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max);
446 XBT_DEBUG("Creating PowerRange for host %s. Idle:%f, Epsilon:%f, AllCores:%f.", host_->get_cname(), idle_power, epsilon_power, max_power);
448 PowerRange range(idle_power, epsilon_power, max_power);
449 power_range_watts_list_.push_back(range);
451 xbt_free(msg_epsilon);
456 } // namespace plugin
457 } // namespace simgrid
459 using simgrid::plugin::HostEnergy;
461 /* **************************** events callback *************************** */
462 static void on_creation(simgrid::s4u::Host& host)
464 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
467 // TODO Trace: set to zero the energy variable associated to host->get_name()
469 host.extension_set(new HostEnergy(&host));
472 static void on_action_state_change(simgrid::kernel::resource::CpuAction const& action,
473 simgrid::kernel::resource::Action::State /*previous*/)
475 for (simgrid::kernel::resource::Cpu* const& cpu : action.cpus()) {
476 simgrid::s4u::Host* host = cpu->get_host();
477 if (host != nullptr) {
478 // If it's a VM, take the corresponding PM
479 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
480 if (vm) // If it's a VM, take the corresponding PM
483 // Get the host_energy extension for the relevant host
484 auto* host_energy = host->extension<HostEnergy>();
486 if (host_energy->get_last_update_time() < surf_get_clock())
487 host_energy->update();
492 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
493 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
494 static void on_host_change(simgrid::s4u::Host const& host)
496 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
499 auto* host_energy = host.extension<HostEnergy>();
501 host_energy->update();
504 static void on_host_destruction(simgrid::s4u::Host const& host)
506 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
509 XBT_INFO("Energy consumption of host %s: %f Joules", host.get_cname(),
510 host.extension<HostEnergy>()->get_consumed_energy());
513 static void on_simulation_end()
515 double total_energy = 0.0; // Total energy consumption (whole platform)
516 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
517 for (simgrid::s4u::Host const* host : simgrid::s4u::Engine::get_instance()->get_all_hosts()) {
518 if (host && dynamic_cast<const simgrid::s4u::VirtualMachine*>(host) == nullptr) { // Ignore virtual machines
519 double energy = host->extension<HostEnergy>()->get_consumed_energy();
520 total_energy += energy;
521 if (host->extension<HostEnergy>()->host_was_used_)
522 used_hosts_energy += energy;
525 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)", total_energy,
526 used_hosts_energy, total_energy - used_hosts_energy);
529 /* **************************** Public interface *************************** */
531 /** @ingroup plugin_host_energy
532 * @brief Enable host energy plugin
533 * @details Enable energy plugin to get joules consumption of each cpu. Call this function before loading your platform.
535 void sg_host_energy_plugin_init()
537 if (HostEnergy::EXTENSION_ID.valid())
540 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
542 simgrid::s4u::Host::on_creation.connect(&on_creation);
543 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
544 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
545 simgrid::s4u::Host::on_destruction.connect(&on_host_destruction);
546 simgrid::s4u::Engine::on_simulation_end.connect(&on_simulation_end);
547 simgrid::kernel::resource::CpuAction::on_state_change.connect(&on_action_state_change);
548 // We may only have one actor on a node. If that actor executes something like
549 // compute -> recv -> compute
550 // the recv operation will not trigger a "CpuAction::on_state_change". This means
551 // that the next trigger would be the 2nd compute, hence ignoring the idle time
552 // during the recv call. By updating at the beginning of a compute, we can
553 // fix that. (If the cpu is not idle, this is not required.)
554 simgrid::s4u::Exec::on_start.connect([](simgrid::s4u::Exec const& activity) {
555 if (activity.get_host_number() == 1) { // We only run on one host
556 simgrid::s4u::Host* host = activity.get_host();
557 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
560 xbt_assert(host != nullptr);
561 host->extension<HostEnergy>()->update();
566 /** @ingroup plugin_host_energy
567 * @brief updates the consumption of all hosts
569 * After this call, sg_host_get_consumed_energy() will not interrupt your process
570 * (until after the next clock update).
572 void sg_host_energy_update_all()
574 simgrid::kernel::actor::simcall([]() {
575 std::vector<simgrid::s4u::Host*> list = simgrid::s4u::Engine::get_instance()->get_all_hosts();
576 for (auto const& host : list)
577 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) { // Ignore virtual machines
578 xbt_assert(host != nullptr);
579 host->extension<HostEnergy>()->update();
584 static void ensure_plugin_inited()
586 if (not HostEnergy::EXTENSION_ID.valid())
587 throw simgrid::xbt::InitializationError("The Energy plugin is not active. Please call sg_host_energy_plugin_init() "
588 "before calling any function related to that plugin.");
591 /** @ingroup plugin_host_energy
592 * @brief Returns the total energy consumed by the host so far (in Joules)
594 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
595 * The result is that the actor requesting this value will be interrupted,
596 * the value will be updated in kernel mode before returning the control to the requesting actor.
598 double sg_host_get_consumed_energy(const_sg_host_t host)
600 ensure_plugin_inited();
601 return host->extension<HostEnergy>()->get_consumed_energy();
604 /** @ingroup plugin_host_energy
605 * @brief Get the amount of watt dissipated when the host is idling
607 double sg_host_get_idle_consumption(const_sg_host_t host)
609 ensure_plugin_inited();
610 return host->extension<HostEnergy>()->get_watt_idle_at(0);
613 /** @ingroup plugin_host_energy
614 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
616 double sg_host_get_idle_consumption_at(const_sg_host_t host, int pstate)
618 ensure_plugin_inited();
619 return host->extension<HostEnergy>()->get_watt_idle_at(pstate);
622 /** @ingroup plugin_host_energy
623 * @brief Get the amount of watt dissipated at the given pstate when the host is at 0 or epsilon% CPU usage.
625 double sg_host_get_wattmin_at(const_sg_host_t host, int pstate)
627 ensure_plugin_inited();
628 return host->extension<HostEnergy>()->get_watt_min_at(pstate);
630 /** @ingroup plugin_host_energy
631 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
633 double sg_host_get_wattmax_at(const_sg_host_t host, int pstate)
635 ensure_plugin_inited();
636 return host->extension<HostEnergy>()->get_watt_max_at(pstate);
638 /** @ingroup plugin_host_energy
639 * @brief Returns the power slope at the given pstate
641 double sg_host_get_power_range_slope_at(const_sg_host_t host, int pstate)
643 ensure_plugin_inited();
644 return host->extension<HostEnergy>()->get_power_range_slope_at(pstate);
646 /** @ingroup plugin_host_energy
647 * @brief Returns the current consumption of the host
649 double sg_host_get_current_consumption(const_sg_host_t host)
651 ensure_plugin_inited();
652 return host->extension<HostEnergy>()->get_current_watts_value();