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().
107 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin");
118 PowerRange(double idle, double min, double max) : idle(idle), min(min), max(max) {}
123 static simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> EXTENSION_ID;
125 explicit HostEnergy(simgrid::s4u::Host* ptr);
128 double getCurrentWattsValue(double cpu_load);
129 double getConsumedEnergy();
130 double getWattMinAt(int pstate);
131 double getWattMaxAt(int pstate);
135 void initWattsRangeList();
136 simgrid::s4u::Host* host = nullptr;
137 std::vector<PowerRange>
138 power_range_watts_list; /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */
140 /* We need to keep track of what pstate has been used, as we will sometimes
141 * be notified only *after* a pstate has been used (but we need to update the energy consumption
142 * with the old pstate!)
147 double watts_off = 0.0; /*< Consumption when the machine is turned off (shutdown) */
148 double total_energy = 0.0; /*< Total energy consumed by the host */
149 double last_updated; /*< Timestamp of the last energy update event*/
152 simgrid::xbt::Extension<simgrid::s4u::Host, HostEnergy> HostEnergy::EXTENSION_ID;
154 /* Computes the consumption so far. Called lazily on need. */
155 void HostEnergy::update()
157 double start_time = this->last_updated;
158 double finish_time = surf_get_clock();
160 double current_speed = host->speed();
162 if (start_time < finish_time) {
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 big if),
167 // which may have changed since that recent update.
169 if (current_speed <= 0)
170 // Some users declare a pstate of speed 0 flops (e.g., to model boot time).
171 // We consider that the machine is then fully loaded. That's arbitrary but it avoids a NaN
174 cpu_load = lmm_constraint_get_usage(host->pimpl_cpu->constraint()) / current_speed;
176 /** Divide by the number of cores here **/
177 cpu_load /= host->pimpl_cpu->coreCount();
179 if (cpu_load > 1) // A machine with a load > 1 consumes as much as a fully loaded machine, not more
182 /* The problem with this model is that the load is always 0 or 1, never something less.
183 * Another possibility could be to model the total energy as
185 * X/(X+Y)*W_idle + Y/(X+Y)*W_burn
187 * where X is the amount of idling cores, and Y the amount of computing cores.
190 double previous_energy = this->total_energy;
192 double instantaneous_consumption;
193 if (this->pstate == -1) // The host was off at the beginning of this time interval
194 instantaneous_consumption = this->watts_off;
196 instantaneous_consumption = this->getCurrentWattsValue(cpu_load);
198 double energy_this_step = instantaneous_consumption * (finish_time - start_time);
200 // TODO Trace: Trace energy_this_step from start_time to finish_time in host->name()
202 this->total_energy = previous_energy + energy_this_step;
203 this->last_updated = finish_time;
205 XBT_DEBUG("[update_energy of %s] period=[%.2f-%.2f]; current power peak=%.0E flop/s; consumption change: %.2f J -> "
207 host->cname(), start_time, finish_time, host->pimpl_cpu->speed_.peak, previous_energy, energy_this_step);
210 /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */
211 this->pstate = host->isOn() ? host->pstate() : -1;
214 HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host(ptr), last_updated(surf_get_clock())
216 initWattsRangeList();
218 const char* off_power_str = host->property("watt_off");
219 if (off_power_str != nullptr) {
220 char* msg = bprintf("Invalid value for property watt_off of host %s: %%s", host->cname());
221 this->watts_off = xbt_str_parse_double(off_power_str, msg);
224 /* watts_off is 0 by default */
227 HostEnergy::~HostEnergy() = default;
229 double HostEnergy::getWattMinAt(int pstate)
231 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->cname());
232 return power_range_watts_list[pstate].min;
235 double HostEnergy::getWattMaxAt(int pstate)
237 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->cname());
238 return power_range_watts_list[pstate].max;
241 /** @brief Computes the power consumed by the host according to the current pstate and processor load */
242 double HostEnergy::getCurrentWattsValue(double cpu_load)
244 xbt_assert(not power_range_watts_list.empty(), "No power range properties specified for host %s", host->cname());
246 /* min_power corresponds to the power consumed when only one core is active */
247 /* max_power is the power consumed at 100% cpu load */
248 auto range = power_range_watts_list.at(this->pstate);
249 double current_power = 0;
250 double min_power = 0;
251 double max_power = 0;
252 double power_slope = 0;
254 if (cpu_load > 0) { /* Something is going on, the machine is not idle */
255 double min_power = range.min;
256 double max_power = range.max;
259 * The min_power states how much we consume when only one single
260 * core is working. This means that when cpu_load == 1/coreCount, then
261 * current_power == min_power.
263 * The maximum must be reached when all cores are working (but 1 core was
264 * already accounted for by min_power)
265 * i.e., we need min_power + (maxCpuLoad-1/coreCount)*power_slope == max_power
266 * (maxCpuLoad is by definition 1)
269 int coreCount = host->coreCount();
270 double coreReciprocal = static_cast<double>(1) / static_cast<double>(coreCount);
272 power_slope = (max_power - min_power) / (1 - coreReciprocal);
274 power_slope = 0; // Should be 0, since max_power == min_power (in this case)
276 current_power = min_power + (cpu_load - coreReciprocal) * power_slope;
277 } else { /* Our machine is idle, take the dedicated value! */
278 current_power = range.idle;
281 XBT_DEBUG("[get_current_watts] min_power=%f, max_power=%f, slope=%f", min_power, max_power, power_slope);
282 XBT_DEBUG("[get_current_watts] Current power (watts) = %f, load = %f", current_power, cpu_load);
284 return current_power;
287 double HostEnergy::getConsumedEnergy()
289 if (last_updated < surf_get_clock()) // We need to simcall this as it modifies the environment
290 simgrid::simix::kernelImmediate(std::bind(&HostEnergy::update, this));
295 void HostEnergy::initWattsRangeList()
297 const char* all_power_values_str = host->property("watt_per_state");
298 if (all_power_values_str == nullptr)
301 std::vector<std::string> all_power_values;
302 boost::split(all_power_values, all_power_values_str, boost::is_any_of(","));
303 XBT_DEBUG("%s: profile: %s, cores: %d", host->cname(), all_power_values_str, host->coreCount());
306 for (auto current_power_values_str : all_power_values) {
307 /* retrieve the power values associated with the current pstate */
308 std::vector<std::string> current_power_values;
309 boost::split(current_power_values, current_power_values_str, boost::is_any_of(":"));
310 if (host->coreCount() == 1) {
311 xbt_assert(current_power_values.size() == 2 || current_power_values.size() == 3,
312 "Power properties incorrectly defined for host %s."
313 "It should be 'Idle:FullSpeed' power values because you have one core only.",
315 if (current_power_values.size() == 2) {
316 // In this case, 1core == AllCores
317 current_power_values.push_back(current_power_values.at(1));
318 } else { // size == 3
319 xbt_assert((current_power_values.at(1)) == (current_power_values.at(2)),
320 "Power properties incorrectly defined for host %s.\n"
321 "The energy profile of mono-cores should be formated as 'Idle:FullSpeed' only.\n"
322 "If you go for a 'Idle:OneCore:AllCores' power profile on mono-cores, then OneCore and AllCores "
327 xbt_assert(current_power_values.size() == 3,
328 "Power properties incorrectly defined for host %s."
329 "It should be 'Idle:OneCore:AllCores' power values because you have more than one core.",
333 /* min_power corresponds to the idle power (cpu load = 0) */
334 /* max_power is the power consumed at 100% cpu load */
335 char* msg_idle = bprintf("Invalid idle value for pstate %d on host %s: %%s", i, host->cname());
336 char* msg_min = bprintf("Invalid OneCore value for pstate %d on host %s: %%s", i, host->cname());
337 char* msg_max = bprintf("Invalid AllCores value for pstate %d on host %s: %%s", i, host->cname());
338 PowerRange range(xbt_str_parse_double((current_power_values.at(0)).c_str(), msg_idle),
339 xbt_str_parse_double((current_power_values.at(1)).c_str(), msg_min),
340 xbt_str_parse_double((current_power_values.at(2)).c_str(), msg_max));
341 power_range_watts_list.push_back(range);
351 using simgrid::energy::HostEnergy;
353 /* **************************** events callback *************************** */
354 static void onCreation(simgrid::s4u::Host& host)
356 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
359 //TODO Trace: set to zero the energy variable associated to host->name()
361 host.extension_set(new HostEnergy(&host));
364 static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf::Action::State previous)
366 for (simgrid::surf::Cpu* cpu : action->cpus()) {
367 simgrid::s4u::Host* host = cpu->getHost();
368 if (host != nullptr) {
370 // If it's a VM, take the corresponding PM
371 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
372 if (vm) // If it's a VM, take the corresponding PM
373 host = vm->pimpl_vm_->getPm();
375 // Get the host_energy extension for the relevant host
376 HostEnergy* host_energy = host->extension<HostEnergy>();
378 if (host_energy->last_updated < surf_get_clock())
379 host_energy->update();
384 /* This callback is fired either when the host changes its state (on/off) ("onStateChange") or its speed
385 * (because the user changed the pstate, or because of external trace events) ("onSpeedChange") */
386 static void onHostChange(simgrid::s4u::Host& host)
388 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
391 HostEnergy* host_energy = host.extension<HostEnergy>();
393 host_energy->update();
396 static void onHostDestruction(simgrid::s4u::Host& host)
398 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
401 HostEnergy* host_energy = host.extension<HostEnergy>();
402 host_energy->update();
403 XBT_INFO("Energy consumption of host %s: %f Joules", host.cname(), host_energy->getConsumedEnergy());
406 static void onSimulationEnd()
408 sg_host_t* host_list = sg_host_list();
409 int host_count = sg_host_count();
410 double total_energy = 0.0; // Total energy consumption (whole platform)
411 double used_hosts_energy = 0.0; // Energy consumed by hosts that computed something
412 for (int i = 0; i < host_count; i++) {
413 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host_list[i]) == nullptr) { // Ignore virtual machines
415 bool host_was_used = (host_list[i]->extension<HostEnergy>()->last_updated != 0);
416 double energy = host_list[i]->extension<HostEnergy>()->getConsumedEnergy();
417 total_energy += energy;
419 used_hosts_energy += energy;
422 XBT_INFO("Total energy consumption: %f Joules (used hosts: %f Joules; unused/idle hosts: %f)",
423 total_energy, used_hosts_energy, total_energy - used_hosts_energy);
427 /* **************************** Public interface *************************** */
430 /** \ingroup plugin_energy
431 * \brief Enable host energy plugin
432 * \details Enable energy plugin to get joules consumption of each cpu. Call this function before #MSG_init().
434 void sg_host_energy_plugin_init()
436 if (HostEnergy::EXTENSION_ID.valid())
439 HostEnergy::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostEnergy>();
441 simgrid::s4u::Host::onCreation.connect(&onCreation);
442 simgrid::s4u::Host::onStateChange.connect(&onHostChange);
443 simgrid::s4u::Host::onSpeedChange.connect(&onHostChange);
444 simgrid::s4u::Host::onDestruction.connect(&onHostDestruction);
445 simgrid::s4u::onSimulationEnd.connect(&onSimulationEnd);
446 simgrid::surf::CpuAction::onStateChange.connect(&onActionStateChange);
449 /** @ingroup plugin_energy
450 * @brief updates the consumption of all hosts
452 * After this call, sg_host_get_consumed_energy() will not interrupt your process
453 * (until after the next clock update).
455 void sg_host_energy_update_all()
457 simgrid::simix::kernelImmediate([]() {
458 std::vector<simgrid::s4u::Host*> list;
459 simgrid::s4u::Engine::instance()->hostList(&list);
460 for (auto host : list)
461 host->extension<HostEnergy>()->update();
465 /** @ingroup plugin_energy
466 * @brief Returns the total energy consumed by the host so far (in Joules)
468 * Please note that since the consumption is lazily updated, it may require a simcall to update it.
469 * The result is that the actor requesting this value will be interrupted,
470 * the value will be updated in kernel mode before returning the control to the requesting actor.
472 double sg_host_get_consumed_energy(sg_host_t host)
474 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
475 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
476 return host->extension<HostEnergy>()->getConsumedEnergy();
479 /** @ingroup plugin_energy
480 * @brief Get the amount of watt dissipated at the given pstate when the host is idling
482 double sg_host_get_wattmin_at(sg_host_t host, int pstate)
484 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
485 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
486 return host->extension<HostEnergy>()->getWattMinAt(pstate);
488 /** @ingroup plugin_energy
489 * @brief Returns the amount of watt dissipated at the given pstate when the host burns CPU at 100%
491 double sg_host_get_wattmax_at(sg_host_t host, int pstate)
493 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
494 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
495 return host->extension<HostEnergy>()->getWattMaxAt(pstate);
498 /** @ingroup plugin_energy
499 * @brief Returns the current consumption of the host
501 double sg_host_get_current_consumption(sg_host_t host)
503 xbt_assert(HostEnergy::EXTENSION_ID.valid(),
504 "The Energy plugin is not active. Please call sg_energy_plugin_init() during initialization.");
505 double cpu_load = lmm_constraint_get_usage(host->pimpl_cpu->constraint()) / host->speed();
506 return host->extension<HostEnergy>()->getCurrentWattsValue(cpu_load);