1 /* Copyright (c) 2010-2017. 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/simix.hpp"
8 #include "src/plugins/vm/VirtualMachineImpl.hpp"
9 #include "src/surf/cpu_interface.hpp"
11 #include "simgrid/s4u/Engine.hpp"
13 #include <boost/algorithm/string/classification.hpp>
14 #include <boost/algorithm/string/split.hpp>
19 /** @addtogroup plugin_energy
21 This is the energy plugin, enabling to account not only for computation time, but also for the dissipated energy in the
23 To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(), and then use
24 MSG_host_get_consumed_energy() to retrieve the consumption of a given host.
26 When the host is on, this energy consumption naturally depends on both the current CPU load and the host energy profile.
27 According to our measurements, the consumption is somehow linear in the amount of cores at full speed, with an
28 abnormality when all the cores are idle. The full details are in
29 <a href="https://hal.inria.fr/hal-01523608">our scientific paper</a> on that topic.
31 As a result, our energy model takes 4 parameters:
33 - \b Idle: instantaneous consumption (in Watt) when your host is up and running, but without anything to do.
34 - \b OneCore: instantaneous consumption (in Watt) when only one core is active, at 100%.
35 - \b AllCores: instantaneous consumption (in Watt) when all cores of the host are at 100%.
36 - \b Off: instantaneous consumption (in Watt) when the host is turned off.
38 Here is an example of XML declaration:
41 <host id="HostA" power="100.0Mf" cores="4">
42 <prop id="watt_per_state" value="100.0:120.0:200.0" />
43 <prop id="watt_off" value="10" />
47 This example gives the following parameters: \b Off is 10 Watts; \b Idle is 100 Watts; \b OneCore is 120 Watts and \b
48 AllCores is 200 Watts.
49 This is enough to compute the consumption as a function of the amount of loaded cores:
52 <tr><th>#Cores loaded</th><th>Consumption</th><th>Explanation</th></tr>
53 <tr><td>0</td><td> 100 Watts</td><td>Idle value</td></tr>
54 <tr><td>1</td><td> 120 Watts</td><td>OneCore value</td></tr>
55 <tr><td>2</td><td> 147 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
56 <tr><td>3</td><td> 173 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
57 <tr><td>4</td><td> 200 Watts</td><td>AllCores value</td></tr>
60 ### What if a given core is only at load 50%?
62 This is impossible in SimGrid because we recompute everything each time that the CPU starts or stops doing something.
63 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
64 the time, and our model holds.
66 ### What if the host has only one core?
68 In this case, the parameters \b OneCore and \b AllCores are obviously the same.
69 Actually, SimGrid expect an energetic profile formatted as 'Idle:Running' for mono-cores hosts.
70 If you insist on passing 3 parameters in this case, then you must have the same value for \b OneCore and \b AllCores.
73 <host id="HostC" power="100.0Mf" cores="1">
74 <prop id="watt_per_state" value="95.0:200.0" /> <!-- we may have used '95:200:200' instead -->
75 <prop id="watt_off" value="10" />
79 ### How does DVFS interact with the host energy model?
81 If your host has several DVFS levels (several pstates), then you should give the energetic profile of each pstate level:
84 <host id="HostC" power="100.0Mf,50.0Mf,20.0Mf" cores="4">
85 <prop id="watt_per_state" value="95.0:120.0:200.0, 93.0:115.0:170.0, 90.0:110.0:150.0" />
86 <prop id="watt_off" value="10" />
90 This encodes the following values
92 <tr><th>pstate</th><th>Performance</th><th>Idle</th><th>OneCore</th><th>AllCores</th></tr>
93 <tr><td>0</td><td>100 Mflop/s</td><td>95 Watts</td><td>120 Watts</td><td>200 Watts</td></tr>
94 <tr><td>1</td><td>50 Mflop/s</td><td>93 Watts</td><td>115 Watts</td><td>170 Watts</td></tr>
95 <tr><td>2</td><td>20 Mflop/s</td><td>90 Watts</td><td>110 Watts</td><td>150 Watts</td></tr>
98 To change the pstate of a given CPU, use the following functions:
99 #MSG_host_get_nb_pstates(), simgrid#s4u#Host#setPstate(), #MSG_host_get_power_peak_at().
101 ### How accurate are these models?
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 <a href="https://hal.inria.fr/hal-01523608">this paper</a> to see all what you need to do
107 before you can get accurate energy predictions.
110 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
121 PowerRange(double idle, double min, double max) : idle(idle), min(min), max(max) {}
126 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
128 explicit HostEnergy(simgrid::s4u::Host* ptr);
131 double getCurrentWattsValue();
132 double getCurrentWattsValue(double cpu_load);
133 double getConsumedEnergy();
134 double getWattMinAt(int pstate);
135 double getWattMaxAt(int pstate);
139 void initWattsRangeList();
140 simgrid::s4u::Host* host = nullptr;
141 std::vector<PowerRange>
142 power_range_watts_list; /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */
144 /* We need to keep track of what pstate has been used, as we will sometimes be notified only *after* a pstate has been
145 * used (but we need to update the energy consumption with the old pstate!)
148 const int pstate_off = -1;
151 double watts_off = 0.0; /*< Consumption when the machine is turned off (shutdown) */
152 double total_energy = 0.0; /*< Total energy consumed by the host */
153 double last_updated; /*< Timestamp of the last energy update event*/
156 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
158 /* Computes the consumption so far. Called lazily on need. */
159 void HostEnergy::update()
161 double start_time = this->last_updated;
162 double finish_time = surf_get_clock();
164 if (start_time < finish_time) {
165 double previous_energy = this->total_energy;
167 double instantaneous_consumption = this->getCurrentWattsValue();
169 double energy_this_step = instantaneous_consumption * (finish_time - start_time);
171 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->getName()
173 this->total_energy = previous_energy + energy_this_step;
174 this->last_updated = finish_time;
176 XBT_DEBUG("[update_energy of %s] period=[%.2f-%.2f]; current power peak=%.0E flop/s; consumption change: %.2f J -> "
178 host->getCname(), start_time, finish_time, host->pimpl_cpu->speed_.peak, previous_energy,
182 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
183 this->pstate = host->isOn() ? host->getPstate() : pstate_off;
186 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host(ptr), last_updated(surf_get_clock())
188 initWattsRangeList();
190 const char* off_power_str = host->getProperty("watt_off");
191 if (off_power_str != nullptr) {
193 this->watts_off = std::stod(std::string(off_power_str));
194 } catch (std::invalid_argument& ia) {
195 throw std::invalid_argument(std::string("Invalid value for property watt_off of host ") + host->getCname() +
196 ": " + off_power_str);
199 /* watts_off is 0 by default */
202 HostEnergy::~HostEnergy() = default;
204 double HostEnergy::getWattMinAt(int pstate)
206 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
207 return power_range_watts_list[pstate].min;
210 double HostEnergy::getWattMaxAt(int pstate)
212 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
213 return power_range_watts_list[pstate].max;
216 /** @brief Computes the power consumed by the host according to the current situation
218 * - If the host is off, that's the watts_off value
219 * - if it's on, take the current pstate and the current processor load into account */
220 double HostEnergy::getCurrentWattsValue()
222 if (this->pstate == pstate_off) // The host is off (or was off at the beginning of this time interval)
223 return this->watts_off;
225 double current_speed = host->getSpeed();
228 // We may have start == finish if the past consumption was updated since the simcall was started
229 // for example if 2 actors requested to update the same host's consumption in a given scheduling round.
231 // Even in this case, we need to save the pstate for the next call (after this big if),
232 // which may have changed since that recent update.
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->constraint()->get_usage() / current_speed;
241 /** Divide by the number of cores here **/
242 cpu_load /= host->pimpl_cpu->coreCount();
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 getCurrentWattsValue(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::getCurrentWattsValue(double cpu_load)
263 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
266 * * Return watts_off if pstate == pstate_off
267 * * this happens when host is off
269 if (this->pstate == pstate_off) {
273 /* min_power corresponds to the power consumed when only one core is active */
274 /* max_power is the power consumed at 100% cpu load */
275 auto range = power_range_watts_list.at(this->pstate);
276 double current_power = 0;
277 double min_power = 0;
278 double max_power = 0;
279 double power_slope = 0;
281 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
282 double min_power = range.min;
283 double max_power = range.max;
286 * The min_power states how much we consume when only one single
287 * core is working. This means that when cpu_load == 1/coreCount, then
288 * current_power == min_power.
290 * The maximum must be reached when all cores are working (but 1 core was
291 * already accounted for by min_power)
292 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
293 * (maxCpuLoad is by definition 1)
296 int coreCount = host->getCoreCount();
297 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
299 power_slope = (max_power - min_power) / (1 - coreReciprocal);
301 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
303 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
304 } else { /* Our machine is idle, take the dedicated value! */
305 current_power = range.idle;
308 XBT_DEBUG("[get_current_watts] min_power=%f, max_power=%f, slope=%f", min_power, max_power, power_slope);
309 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
311 return current_power;
314 double HostEnergy::getConsumedEnergy()
316 if (last_updated < surf_get_clock()) // We need to simcall this as it modifies the environment
317 simgrid::simix::kernelImmediate(std::bind(&HostEnergy::update, this));
322 void HostEnergy::initWattsRangeList()
324 const char* all_power_values_str = host->getProperty("watt_per_state");
325 if (all_power_values_str == nullptr)
328 std::vector<std::string> all_power_values;
329 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
330 XBT_DEBUG("%s: profile: %s, cores: %d", host->getCname(), all_power_values_str, host->getCoreCount());
333 for (auto const& current_power_values_str : all_power_values) {
334 /* retrieve the power values associated with the current pstate */
335 std::vector<std::string> current_power_values;
336 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
337 if (host->getCoreCount() == 1) {
338 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
339 "Power properties incorrectly defined for host %s."
340 "It should be 'Idle:FullSpeed' power values because you have one core only.",
342 if (current_power_values.size() == 2) {
343 // In this case, 1core == AllCores
344 current_power_values.push_back(current_power_values.at(1));
345 } else { // size == 3
346 xbt_assert((current_power_values.at(1)) == (current_power_values.at(2)),
347 "Power properties incorrectly defined for host %s.\n"
348 "The energy profile of mono-cores should be formatted as 'Idle:FullSpeed' only.\n"
349 "If you go for a 'Idle:OneCore:AllCores' power profile on mono-cores, then OneCore and AllCores "
354 xbt_assert(current_power_values.size() == 3,
355 "Power properties incorrectly defined for host %s."
356 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
360 /* min_power corresponds to the idle power (cpu load = 0) */
361 /* max_power is the power consumed at 100% cpu load */
362 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host->getCname());
363 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host->getCname());
364 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host->getCname());
365 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
366 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
367 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
368 power_range_watts_list.push_back(range);
378 using simgrid::plugin::HostEnergy;
380 /* **************************** events callback *************************** */
381 static void onCreation(simgrid::s4u::Host& host)
383 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
386 // TODO Trace: set to zero the energy variable associated to host->getName()
388 host.extension_set(new HostEnergy(&host));
391 static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf::Action::State previous)
393 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
394 simgrid::s4u::Host* host = cpu->getHost();
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 onHostChange(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 onHostDestruction(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.getCname(),
429 host.extension<HostEnergy>()->getConsumedEnergy());
432 static void onSimulationEnd()
434 sg_host_t* host_list = sg_host_list();
435 int host_count = sg_host_count();
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 (int i = 0; i < host_count; i++) {
439 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host_list[i]) == nullptr) { // Ignore virtual machines
441 bool host_was_used = (host_list[i]->extension<HostEnergy>()->last_updated != 0);
442 double energy = host_list[i]->extension<HostEnergy>()->getConsumedEnergy();
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)",
449 total_energy, used_hosts_energy, total_energy - used_hosts_energy);
453 /* **************************** 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 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
467 simgrid::s4u::Host::onCreation.connect(&onCreation);
468 simgrid::s4u::Host::onStateChange.connect(&onHostChange);
469 simgrid::s4u::Host::onSpeedChange.connect(&onHostChange);
470 simgrid::s4u::Host::onDestruction.connect(&onHostDestruction);
471 simgrid::s4u::onSimulationEnd.connect(&onSimulationEnd);
472 simgrid::surf::CpuAction::onStateChange.connect(&onActionStateChange);
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::kernelImmediate([]() {
484 std::vector<simgrid::s4u::Host*> list;
485 simgrid::s4u::Engine::getInstance()->getHostList(&list);
486 for (auto const& host : list)
487 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) // Ignore virtual machines
488 host->extension<HostEnergy>()->update();
492 /** @ingroup plugin_energy
493 * @brief Returns the total energy consumed by the host so far (in Joules)
495 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
496 * The result is that the actor requesting this value will be interrupted,
497 * the value will be updated in kernel mode before returning the control to the requesting actor.
499 double sg_host_get_consumed_energy(sg_host_t host)
501 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
502 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
503 return host->extension<HostEnergy>()->getConsumedEnergy();
506 /** @ingroup plugin_energy
507 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
509 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
511 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
512 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
513 return host->extension<HostEnergy>()->getWattMinAt(pstate);
515 /** @ingroup plugin_energy
516 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
518 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
520 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
521 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
522 return host->extension<HostEnergy>()->getWattMaxAt(pstate);
525 /** @ingroup plugin_energy
526 * @brief Returns the current consumption of the host
528 double sg_host_get_current_consumption(sg_host_t host)
530 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
531 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
532 return host->extension<HostEnergy>()->getCurrentWattsValue();