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
22 This is the energy plugin, enabling to account not only for computation time,
23 but also for the dissipated energy in the simulated platform.
24 To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(),
25 and then use MSG_host_get_consumed_energy() to retrieve the consumption of a given host.
27 When the host is on, this energy consumption naturally depends on both the
28 current CPU load and the host energy profile. According to our measurements,
29 the consumption is somehow linear in the amount of cores at full speed,
30 with an abnormality when all the cores are idle. The full details are in
31 <a href="https://hal.inria.fr/hal-01523608">our scientific paper</a> on that topic.
33 As a result, our energy model takes 4 parameters:
35 - \b Idle: instantaneous consumption (in Watt) when your host is up and running, but without anything to do.
36 - \b OneCore: instantaneous consumption (in Watt) when only one core is active, at 100%.
37 - \b AllCores: instantaneous consumption (in Watt) when all cores of the host are at 100%.
38 - \b Off: instantaneous consumption (in Watt) when the host is turned off.
40 Here is an example of XML declaration:
43 <host id="HostA" power="100.0Mf" cores="4">
44 <prop id="watt_per_state" value="100.0:120.0:200.0" />
45 <prop id="watt_off" value="10" />
49 This example gives the following parameters: \b Off is 10 Watts; \b Idle is 100 Watts; \b OneCore is 120 Watts and \b
50 AllCores is 200 Watts.
51 This is enough to compute the consumption as a function of the amount of loaded cores:
54 <tr><th>#Cores loaded</th><th>Consumption</th><th>Explanation</th></tr>
55 <tr><td>0</td><td> 100 Watts</td><td>Idle value</td></tr>
56 <tr><td>1</td><td> 120 Watts</td><td>OneCore value</td></tr>
57 <tr><td>2</td><td> 147 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
58 <tr><td>3</td><td> 173 Watts</td><td>linear extrapolation between OneCore and AllCores</td></tr>
59 <tr><td>4</td><td> 200 Watts</td><td>AllCores value</td></tr>
62 ### What if a given core is only at load 50%?
64 This is impossible in SimGrid because we recompute everything each time
65 that the CPU starts or stops doing something. So if a core is at load 50% over
66 a period, it means that it is at load 100% half of the time and at load 0% the
67 rest of the time, and our model holds.
69 ### What if the host has only one core?
71 In this case, the parameters \b OneCore and \b AllCores are obviously the same.
72 Actually, SimGrid expect an energetic profile formated as 'Idle:Running' for mono-cores hosts.
73 If you insist on passing 3 parameters in this case, then you must have the same value for \b OneCore and \b AllCores.
76 <host id="HostC" power="100.0Mf" cores="1">
77 <prop id="watt_per_state" value="95.0:200.0" /> <!-- we may have used '95:200:200' instead -->
78 <prop id="watt_off" value="10" />
82 ### How does DVFS interact with the host energy model?
84 If your host has several DVFS levels (several pstates), then you should
85 give the energetic profile of each pstate level:
88 <host id="HostC" power="100.0Mf,50.0Mf,20.0Mf" cores="4">
89 <prop id="watt_per_state" value="95.0:120.0:200.0, 93.0:115.0:170.0, 90.0:110.0:150.0" />
90 <prop id="watt_off" value="10" />
94 This encodes the following values
96 <tr><th>pstate</th><th>Performance</th><th>Idle</th><th>OneCore</th><th>AllCores</th></tr>
97 <tr><td>0</td><td>100 Mflop/s</td><td>95 Watts</td><td>120 Watts</td><td>200 Watts</td></tr>
98 <tr><td>1</td><td>50 Mflop/s</td><td>93 Watts</td><td>115 Watts</td><td>170 Watts</td></tr>
99 <tr><td>2</td><td>20 Mflop/s</td><td>90 Watts</td><td>110 Watts</td><td>150 Watts</td></tr>
102 To change the pstate of a given CPU, use the following functions:
103 #MSG_host_get_nb_pstates(), simgrid#s4u#Host#setPstate(), #MSG_host_get_power_peak_at().
105 ### How accurate are these models?
107 This model cannot be more accurate than your instantiation:
108 with the default values, your result will not be accurate at all. You can still get
109 accurate energy prediction, provided that you carefully instantiate the model.
110 The first step is to ensure that your timing prediction match perfectly. But this
111 is only the first step of the path, and you really want to read
112 <a href="https://hal.inria.fr/hal-01523608">this paper</a> to see all what you need
113 to do before you can get accurate energy predictions.
117 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
128 PowerRange(double idle, double min, double max) : idle(idle), min(min), max(max) {}
133 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
135 explicit HostEnergy(simgrid::s4u::Host* ptr);
138 double getCurrentWattsValue(double cpu_load);
139 double getConsumedEnergy();
140 double getWattMinAt(int pstate);
141 double getWattMaxAt(int pstate);
145 void initWattsRangeList();
146 simgrid::s4u::Host* host = nullptr;
147 std::vector<PowerRange>
148 power_range_watts_list; /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */
150 /* We need to keep track of what pstate has been used, as we will sometimes
151 * be notified only *after* a pstate has been used (but we need to update the energy consumption
152 * with the old pstate!)
155 const int pstate_off = -1;
158 double watts_off = 0.0; /*< Consumption when the machine is turned off (shutdown) */
159 double total_energy = 0.0; /*< Total energy consumed by the host */
160 double last_updated; /*< Timestamp of the last energy update event*/
163 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
165 /* Computes the consumption so far. Called lazily on need. */
166 void HostEnergy::update()
168 double start_time = this->last_updated;
169 double finish_time = surf_get_clock();
170 double current_speed = host->getSpeed();
172 if (start_time < finish_time) {
174 // We may have start == finish if the past consumption was updated since the simcall was started
175 // for example if 2 actors requested to update the same host's consumption in a given scheduling round.
177 // Even in this case, we need to save the pstate for the next call (after this big if),
178 // which may have changed since that recent update.
180 if (current_speed <= 0)
181 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
182 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
185 cpu_load = lmm_constraint_get_usage(host->pimpl_cpu->constraint()) / current_speed;
187 /** Divide by the number of cores here **/
188 cpu_load /= host->pimpl_cpu->coreCount();
190 if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
193 /* The problem with this model is that the load is always 0 or 1, never something less.
194 * Another possibility could be to model the total energy as
196 * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
198 * where X is the amount of idling cores, and Y the amount of computing cores.
201 double previous_energy = this->total_energy;
203 double instantaneous_consumption;
204 if (this->pstate == pstate_off) // The host was off at the beginning of this time interval
205 instantaneous_consumption = this->watts_off;
207 instantaneous_consumption = this->getCurrentWattsValue(cpu_load);
209 double energy_this_step = instantaneous_consumption * (finish_time - start_time);
211 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->name()
213 this->total_energy = previous_energy + energy_this_step;
214 this->last_updated = finish_time;
216 XBT_DEBUG("[update_energy of %s] period=[%.2f-%.2f]; current power peak=%.0E flop/s; consumption change: %.2f J -> "
218 host->getCname(), start_time, finish_time, host->pimpl_cpu->speed_.peak, previous_energy,
222 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
223 this->pstate = host->isOn() ? host->getPstate() : pstate_off;
226 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host(ptr), last_updated(surf_get_clock())
228 initWattsRangeList();
230 const char* off_power_str = host->getProperty("watt_off");
231 if (off_power_str != nullptr) {
232 char* msg = bprintf("Invalid value for property watt_off of host %s: %%s", host->getCname());
233 this->watts_off = xbt_str_parse_double(off_power_str, msg);
236 /* watts_off is 0 by default */
239 HostEnergy::~HostEnergy() = default;
241 double HostEnergy::getWattMinAt(int pstate)
243 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
244 return power_range_watts_list[pstate].min;
247 double HostEnergy::getWattMaxAt(int pstate)
249 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
250 return power_range_watts_list[pstate].max;
253 /** @brief Computes the power consumed by the host according to the current pstate and processor load */
254 double HostEnergy::getCurrentWattsValue(double cpu_load)
256 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->getCname());
258 /* min_power corresponds to the power consumed when only one core is active */
259 /* max_power is the power consumed at 100% cpu load */
260 auto range = power_range_watts_list.at(this->pstate);
261 double current_power = 0;
262 double min_power = 0;
263 double max_power = 0;
264 double power_slope = 0;
266 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
267 double min_power = range.min;
268 double max_power = range.max;
271 * The min_power states how much we consume when only one single
272 * core is working. This means that when cpu_load == 1/coreCount, then
273 * current_power == min_power.
275 * The maximum must be reached when all cores are working (but 1 core was
276 * already accounted for by min_power)
277 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
278 * (maxCpuLoad is by definition 1)
281 int coreCount = host->getCoreCount();
282 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
284 power_slope = (max_power - min_power) / (1 - coreReciprocal);
286 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
288 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
289 } else { /* Our machine is idle, take the dedicated value! */
290 current_power = range.idle;
293 XBT_DEBUG("[get_current_watts] min_power=%f, max_power=%f, slope=%f", min_power, max_power, power_slope);
294 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
296 return current_power;
299 double HostEnergy::getConsumedEnergy()
301 if (last_updated < surf_get_clock()) // We need to simcall this as it modifies the environment
302 simgrid::simix::kernelImmediate(std::bind(&HostEnergy::update, this));
307 void HostEnergy::initWattsRangeList()
309 const char* all_power_values_str = host->getProperty("watt_per_state");
310 if (all_power_values_str == nullptr)
313 std::vector<std::string> all_power_values;
314 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
315 XBT_DEBUG("%s: profile: %s, cores: %d", host->getCname(), all_power_values_str, host->getCoreCount());
318 for (auto current_power_values_str : all_power_values) {
319 /* retrieve the power values associated with the current pstate */
320 std::vector<std::string> current_power_values;
321 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
322 if (host->getCoreCount() == 1) {
323 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
324 "Power properties incorrectly defined for host %s."
325 "It should be 'Idle:FullSpeed' power values because you have one core only.",
327 if (current_power_values.size() == 2) {
328 // In this case, 1core == AllCores
329 current_power_values.push_back(current_power_values.at(1));
330 } else { // size == 3
331 xbt_assert((current_power_values.at(1)) == (current_power_values.at(2)),
332 "Power properties incorrectly defined for host %s.\n"
333 "The energy profile of mono-cores should be formated as 'Idle:FullSpeed' only.\n"
334 "If you go for a 'Idle:OneCore:AllCores' power profile on mono-cores, then OneCore and AllCores "
339 xbt_assert(current_power_values.size() == 3,
340 "Power properties incorrectly defined for host %s."
341 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
345 /* min_power corresponds to the idle power (cpu load = 0) */
346 /* max_power is the power consumed at 100% cpu load */
347 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host->getCname());
348 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host->getCname());
349 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host->getCname());
350 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
351 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
352 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
353 power_range_watts_list.push_back(range);
363 using simgrid::energy::HostEnergy;
365 /* **************************** events callback *************************** */
366 static void onCreation(simgrid::s4u::Host& host)
368 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
371 //TODO Trace: set to zero the energy variable associated to host->name()
373 host.extension_set(new HostEnergy(&host));
376 static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf::Action::State previous)
378 for (simgrid::surf::Cpu* cpu : action->cpus()) {
379 simgrid::s4u::Host* host = cpu->getHost();
380 if (host != nullptr) {
382 // If it's a VM, take the corresponding PM
383 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
384 if (vm) // If it's a VM, take the corresponding PM
385 host = vm->pimpl_vm_->getPm();
387 // Get the host_energy extension for the relevant host
388 HostEnergy* host_energy = host->extension<HostEnergy>();
390 if (host_energy->last_updated < surf_get_clock())
391 host_energy->update();
396 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
397 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
398 static void onHostChange(simgrid::s4u::Host& host)
400 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
403 HostEnergy* host_energy = host.extension<HostEnergy>();
405 host_energy->update();
408 static void onHostDestruction(simgrid::s4u::Host& host)
410 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
413 HostEnergy* host_energy = host.extension<HostEnergy>();
414 host_energy->update();
415 XBT_INFO("Energy consumption of host %s: %f Joules", host.getCname(), host_energy->getConsumedEnergy());
418 static void onSimulationEnd()
420 sg_host_t* host_list = sg_host_list();
421 int host_count = sg_host_count();
422 double total_energy = 0.0; // Total energy consumption (whole platform)
423 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
424 for (int i = 0; i < host_count; i++) {
425 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host_list[i]) == nullptr) { // Ignore virtual machines
427 bool host_was_used = (host_list[i]->extension<HostEnergy>()->last_updated != 0);
428 double energy = host_list[i]->extension<HostEnergy>()->getConsumedEnergy();
429 total_energy += energy;
431 used_hosts_energy += energy;
434 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)",
435 total_energy, used_hosts_energy, total_energy - used_hosts_energy);
439 /* **************************** Public interface *************************** */
442 /** \ingroup plugin_energy
443 * \brief Enable host energy plugin
444 * \details Enable energy plugin to get joules consumption of each cpu. Call this function before #MSG_init().
446 void sg_host_energy_plugin_init()
448 if (HostEnergy::EXTENSION_ID.valid())
451 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
453 simgrid::s4u::Host::onCreation.connect(&onCreation);
454 simgrid::s4u::Host::onStateChange.connect(&onHostChange);
455 simgrid::s4u::Host::onSpeedChange.connect(&onHostChange);
456 simgrid::s4u::Host::onDestruction.connect(&onHostDestruction);
457 simgrid::s4u::onSimulationEnd.connect(&onSimulationEnd);
458 simgrid::surf::CpuAction::onStateChange.connect(&onActionStateChange);
461 /** @ingroup plugin_energy
462 * @brief updates the consumption of all hosts
464 * After this call, sg_host_get_consumed_energy() will not interrupt your process
465 * (until after the next clock update).
467 void sg_host_energy_update_all()
469 simgrid::simix::kernelImmediate([]() {
470 std::vector<simgrid::s4u::Host*> list;
471 simgrid::s4u::Engine::getInstance()->getHostList(&list);
472 for (auto host : list)
473 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host) == nullptr) // Ignore virtual machines
474 host->extension<HostEnergy>()->update();
478 /** @ingroup plugin_energy
479 * @brief Returns the total energy consumed by the host so far (in Joules)
481 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
482 * The result is that the actor requesting this value will be interrupted,
483 * the value will be updated in kernel mode before returning the control to the requesting actor.
485 double sg_host_get_consumed_energy(sg_host_t host)
487 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
488 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
489 return host->extension<HostEnergy>()->getConsumedEnergy();
492 /** @ingroup plugin_energy
493 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
495 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
497 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
498 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
499 return host->extension<HostEnergy>()->getWattMinAt(pstate);
501 /** @ingroup plugin_energy
502 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
504 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
506 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
507 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
508 return host->extension<HostEnergy>()->getWattMaxAt(pstate);
511 /** @ingroup plugin_energy
512 * @brief Returns the current consumption of the host
514 double sg_host_get_current_consumption(sg_host_t host)
516 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
517 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
518 double cpu_load = lmm_constraint_get_usage(host->pimpl_cpu->constraint()) / host->getSpeed();
519 return host->extension<HostEnergy>()->getCurrentWattsValue(cpu_load);