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/dvfs.h"
7 #include "simgrid/plugins/load.h"
8 #include "simgrid/s4u/Engine.hpp"
9 #include "src/kernel/activity/ExecImpl.hpp"
10 #include "src/plugins/vm/VirtualMachineImpl.hpp"
11 #include "src/smpi/plugins/ampi/ampi.hpp"
12 #include <xbt/config.hpp>
14 #include <boost/algorithm/string.hpp>
16 SIMGRID_REGISTER_PLUGIN(host_dvfs, "Dvfs support", &sg_host_dvfs_plugin_init)
18 static simgrid::config::Flag<double> cfg_sampling_rate("plugin/dvfs/sampling-rate", {"plugin/dvfs/sampling_rate"},
19 "How often should the dvfs plugin check whether the frequency needs to be changed?", 0.1,
20 [](double val){if (val != 0.1) sg_host_dvfs_plugin_init();});
22 static simgrid::config::Flag<std::string> cfg_governor("plugin/dvfs/governor",
23 "Which Governor should be used that adapts the CPU frequency?", "performance",
25 std::map<std::string, std::string>({
26 {"adagio", "TODO: Doc"},
27 {"conservative", "TODO: Doc"},
28 {"ondemand", "TODO: Doc"},
29 {"performance", "TODO: Doc"},
30 {"powersave", "TODO: Doc"},
33 [](std::string val) { if (val != "performance") sg_host_dvfs_plugin_init(); });
35 static simgrid::config::Flag<int> cfg_min_pstate("plugin/dvfs/min-pstate", {"plugin/dvfs/min_pstate"},
36 "Which pstate is the minimum (and hence fastest) pstate for this governor?", 0,
39 static const int max_pstate_not_limited = -1;
40 static simgrid::config::Flag<int> cfg_max_pstate("plugin/dvfs/max-pstate", {"plugin/dvfs/max_pstate"},
41 "Which pstate is the maximum (and hence slowest) pstate for this governor?", max_pstate_not_limited,
44 /** @addtogroup SURF_plugin_load
46 This plugin makes it very simple for users to obtain the current load for each host.
50 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_dvfs, surf, "Logging specific to the SURF HostDvfs plugin");
58 * Add this to your host tag:
59 * - \<prop id="plugin/dvfs/governor" value="performance" /\>
61 * Valid values as of now are: performance, powersave, ondemand, conservative
62 * It doesn't matter if you use uppercase or lowercase.
64 * For the sampling rate, use this:
66 * - \<prop id="plugin/dvfs/sampling-rate" value="2" /\>
68 * This will run the update() method of the specified governor every 2 seconds
71 * These properties can also be used within the \<config\> tag to configure
72 * these values globally. Using them within the \<host\> will overwrite this
73 * global configuration
78 simgrid::s4u::Host* const host_;
79 double sampling_rate_;
84 explicit Governor(simgrid::s4u::Host* ptr)
86 , min_pstate(cfg_min_pstate)
87 , max_pstate(cfg_max_pstate == max_pstate_not_limited ? host_->get_pstate_count() - 1 : cfg_max_pstate)
91 virtual ~Governor() = default;
92 virtual std::string get_name() const = 0;
93 simgrid::s4u::Host* get_host() const { return host_; }
97 const char* local_sampling_rate_config = host_->get_property(cfg_sampling_rate.get_name());
98 if (local_sampling_rate_config != nullptr) {
99 sampling_rate_ = std::stod(local_sampling_rate_config);
101 sampling_rate_ = cfg_sampling_rate;
103 const char* local_min_pstate_config = host_->get_property(cfg_min_pstate.get_name());
104 if (local_min_pstate_config != nullptr) {
105 min_pstate = std::stoi(local_min_pstate_config);
108 const char* local_max_pstate_config = host_->get_property(cfg_max_pstate.get_name());
109 if (local_max_pstate_config != nullptr) {
110 max_pstate = std::stod(local_max_pstate_config);
112 xbt_assert(max_pstate <= host_->get_pstate_count() - 1, "Value for max_pstate too large!");
113 xbt_assert(min_pstate <= max_pstate, "min_pstate is larger than max_pstate!");
114 xbt_assert(0 <= min_pstate, "min_pstate is negative!");
117 virtual void update() = 0;
118 double get_sampling_rate() const { return sampling_rate_; }
122 * The linux kernel doc describes this governor as follows:
123 * https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
125 * > The CPUfreq governor "performance" sets the CPU statically to the
126 * > highest frequency within the borders of scaling_min_freq and
127 * > scaling_max_freq.
129 * We do not support scaling_min_freq/scaling_max_freq -- we just pick the lowest frequency.
131 class Performance : public Governor {
133 explicit Performance(simgrid::s4u::Host* ptr) : Governor(ptr) {}
134 std::string get_name() const override { return "Performance"; }
136 void update() override { get_host()->set_pstate(min_pstate); }
140 * The linux kernel doc describes this governor as follows:
141 * https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
143 * > The CPUfreq governor "powersave" sets the CPU statically to the
144 * > lowest frequency within the borders of scaling_min_freq and
145 * > scaling_max_freq.
147 * We do not support scaling_min_freq/scaling_max_freq -- we just pick the lowest frequency.
149 class Powersave : public Governor {
151 explicit Powersave(simgrid::s4u::Host* ptr) : Governor(ptr) {}
152 std::string get_name() const override { return "Powersave"; }
154 void update() override { get_host()->set_pstate(max_pstate); }
158 * The linux kernel doc describes this governor as follows:
159 * https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt
161 * > The CPUfreq governor "ondemand" sets the CPU frequency depending on the
162 * > current system load. [...] when triggered, cpufreq checks
163 * > the CPU-usage statistics over the last period and the governor sets the
166 class OnDemand : public Governor {
168 * See https://elixir.bootlin.com/linux/v4.15.4/source/drivers/cpufreq/cpufreq_ondemand.c
169 * DEF_FREQUENCY_UP_THRESHOLD and od_update()
171 double freq_up_threshold_ = 0.80;
174 explicit OnDemand(simgrid::s4u::Host* ptr) : Governor(ptr) {}
175 std::string get_name() const override { return "OnDemand"; }
177 void update() override
179 double load = get_host()->get_core_count() * sg_host_get_avg_load(get_host());
180 sg_host_load_reset(get_host()); // Only consider the period between two calls to this method!
182 if (load > freq_up_threshold_) {
183 get_host()->set_pstate(min_pstate); /* Run at max. performance! */
184 XBT_INFO("Load: %f > threshold: %f --> changed to pstate %i", load, freq_up_threshold_, min_pstate);
186 /* The actual implementation uses a formula here: (See Kernel file cpufreq_ondemand.c:158)
188 * freq_next = min_f + load * (max_f - min_f) / 100
190 * So they assume that frequency increases by 100 MHz. We will just use
191 * lowest_pstate - load*pstatesCount()
193 // Load is now < freq_up_threshold; exclude pstate 0 (the fastest)
194 // because pstate 0 can only be selected if load > freq_up_threshold_
195 int new_pstate = get_max_pstate() - load * (get_max_pstate() + 1);
196 if (new_pstate < get_min_pstate())
197 new_pstate = get_min_pstate();
198 get_host()->set_pstate(new_pstate);
200 XBT_DEBUG("Load: %f < threshold: %f --> changed to pstate %i", load, freq_up_threshold_, new_pstate);
207 * This is the conservative governor, which is very similar to the
208 * OnDemand governor. The Linux Kernel Documentation describes it
209 * very well, see https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt:
211 * > The CPUfreq governor "conservative", much like the "ondemand"
212 * > governor, sets the CPU frequency depending on the current usage. It
213 * > differs in behaviour in that it gracefully increases and decreases the
214 * > CPU speed rather than jumping to max speed the moment there is any load
215 * > on the CPU. This behaviour is more suitable in a battery powered
218 class Conservative : public Governor {
219 double freq_up_threshold_ = .8;
220 double freq_down_threshold_ = .2;
223 explicit Conservative(simgrid::s4u::Host* ptr) : Governor(ptr) {}
224 virtual std::string get_name() const override { return "Conservative"; }
226 virtual void update() override
228 double load = get_host()->get_core_count() * sg_host_get_avg_load(get_host());
229 int pstate = get_host()->get_pstate();
230 sg_host_load_reset(get_host()); // Only consider the period between two calls to this method!
232 if (load > freq_up_threshold_) {
233 if (pstate != min_pstate) {
234 get_host()->set_pstate(pstate - 1);
235 XBT_INFO("Load: %f > threshold: %f -> increasing performance to pstate %d", load, freq_up_threshold_,
238 XBT_DEBUG("Load: %f > threshold: %f -> but cannot speed up even more, already in highest pstate %d", load,
239 freq_up_threshold_, pstate);
241 } else if (load < freq_down_threshold_) {
242 if (pstate != max_pstate) { // Are we in the slowest pstate already?
243 get_host()->set_pstate(pstate + 1);
244 XBT_INFO("Load: %f < threshold: %f -> slowing down to pstate %d", load, freq_down_threshold_, pstate + 1);
246 XBT_DEBUG("Load: %f < threshold: %f -> cannot slow down even more, already in slowest pstate %d", load,
247 freq_down_threshold_, pstate);
253 class Adagio : public Governor {
256 double start_time = 0;
257 double comp_counter = 0;
258 double comp_timer = 0;
260 std::vector<std::vector<double>> rates;
262 unsigned int task_id = 0;
263 bool iteration_running = false; /*< Are we currently between iteration_in and iteration_out calls? */
266 explicit Adagio(simgrid::s4u::Host* ptr)
267 : Governor(ptr), rates(100, std::vector<double>(host_->get_pstate_count(), 0.0))
269 simgrid::smpi::plugin::ampi::on_iteration_in.connect([this](simgrid::s4u::ActorPtr actor) {
270 // Every instance of this class subscribes to this event, so one per host
271 // This means that for any actor, all 'hosts' are normally notified of these
272 // changes, even those who don't currently run the actor 'proc_id'.
273 // -> Let's check if this signal call is for us!
274 if (get_host() == actor->get_host()) {
275 iteration_running = true;
278 simgrid::smpi::plugin::ampi::on_iteration_out.connect([this](simgrid::s4u::ActorPtr actor) {
279 if (get_host() == actor->get_host()) {
280 iteration_running = false;
284 simgrid::kernel::activity::ExecImpl::on_creation.connect([this](simgrid::kernel::activity::ExecImplPtr activity) {
285 if (activity->host_ == get_host())
288 simgrid::kernel::activity::ExecImpl::on_completion.connect([this](simgrid::kernel::activity::ExecImplPtr activity) {
289 // For more than one host (not yet supported), we can access the host via
290 // simcalls_.front()->issuer->iface()->get_host()
291 if (activity->host_ == get_host() && iteration_running) {
292 comp_timer += activity->surf_action_->get_finish_time() - activity->surf_action_->get_start_time();
295 simgrid::s4u::Link::on_communicate.connect(
296 [this](kernel::resource::NetworkAction* action, s4u::Host* src, s4u::Host* dst) {
297 if ((get_host() == src || get_host() == dst) && iteration_running) {
303 virtual std::string get_name() const override { return "Adagio"; }
307 sg_host_load_reset(host_);
308 comp_counter = sg_host_get_computed_flops(host_); // Should be 0 because of the reset
310 start_time = simgrid::s4u::Engine::get_clock();
311 if (rates.size() <= task_id)
312 rates.resize(task_id + 5, std::vector<double>(host_->get_pstate_count(), 0.0));
313 if (rates[task_id][best_pstate] == 0)
315 host_->set_pstate(best_pstate); // Load our schedule
316 XBT_DEBUG("Set pstate to %i", best_pstate);
321 double computed_flops = sg_host_get_computed_flops(host_) - comp_counter;
322 double target_time = (simgrid::s4u::Engine::get_clock() - start_time);
325 static_cast<double>(99.0 / 100.0); // FIXME We account for t_copy arbitrarily with 1% -- this needs to be fixed
327 bool is_initialized = rates[task_id][best_pstate] != 0;
328 rates[task_id][best_pstate] = computed_flops / comp_timer;
329 if (not is_initialized) {
330 for (int i = 1; i < host_->get_pstate_count(); i++) {
331 rates[task_id][i] = rates[task_id][0] * (host_->get_pstate_speed(i) / host_->get_speed());
333 is_initialized = true;
336 for (int pstate = host_->get_pstate_count() - 1; pstate >= 0; pstate--) {
337 if (computed_flops / rates[task_id][pstate] <= target_time) {
338 // We just found the pstate we want to use!
339 best_pstate = pstate;
346 virtual void update() override {}
349 } // namespace plugin
350 } // namespace simgrid
352 /* **************************** events callback *************************** */
353 static void on_host_added(simgrid::s4u::Host& host)
355 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
358 std::string name = std::string("dvfs-daemon-") + host.get_cname();
359 simgrid::s4u::ActorPtr daemon = simgrid::s4u::Actor::create(name.c_str(), &host, []() {
361 * This lambda function is the function the actor (daemon) will execute
362 * all the time - in the case of the dvfs plugin, this controls when to
363 * lower/raise the frequency.
365 simgrid::s4u::ActorPtr daemon_proc = simgrid::s4u::Actor::self();
367 XBT_DEBUG("DVFS process on %s is a daemon: %d", daemon_proc->get_host()->get_cname(), daemon_proc->is_daemon());
369 std::string dvfs_governor;
370 const char* host_conf = daemon_proc->get_host()->get_property("plugin/dvfs/governor");
371 if (host_conf != nullptr) {
372 dvfs_governor = std::string(host_conf);
373 boost::algorithm::to_lower(dvfs_governor);
375 dvfs_governor = cfg_governor;
376 boost::algorithm::to_lower(dvfs_governor);
379 auto governor = [&dvfs_governor, &daemon_proc]() {
380 if (dvfs_governor == "conservative") {
381 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
382 new simgrid::plugin::dvfs::Conservative(daemon_proc->get_host()));
383 } else if (dvfs_governor == "ondemand") {
384 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
385 new simgrid::plugin::dvfs::OnDemand(daemon_proc->get_host()));
386 } else if (dvfs_governor == "adagio") {
387 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
388 new simgrid::plugin::dvfs::Adagio(daemon_proc->get_host()));
389 } else if (dvfs_governor == "performance") {
390 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
391 new simgrid::plugin::dvfs::Performance(daemon_proc->get_host()));
392 } else if (dvfs_governor == "powersave") {
393 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
394 new simgrid::plugin::dvfs::Powersave(daemon_proc->get_host()));
396 XBT_CRITICAL("No governor specified for host %s, falling back to Performance",
397 daemon_proc->get_host()->get_cname());
398 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
399 new simgrid::plugin::dvfs::Performance(daemon_proc->get_host()));
404 // Sleep *before* updating; important for startup (i.e., t = 0).
405 // In the beginning, we want to go with the pstates specified in the platform file
406 // (so we sleep first)
407 simgrid::s4u::this_actor::sleep_for(governor->get_sampling_rate());
409 XBT_DEBUG("Governor (%s) just updated!", governor->get_name().c_str());
412 XBT_WARN("I should have never reached this point: daemons should be killed when all regular processes are done");
416 // This call must be placed in this function. Otherwise, the daemonize() call comes too late and
417 // SMPI will take this process as an MPI process!
421 /* **************************** Public interface *************************** */
423 /** @ingroup SURF_plugin_load
424 * @brief Initializes the HostDvfs plugin
425 * @details The HostDvfs plugin provides an API to get the current load of each host.
427 void sg_host_dvfs_plugin_init()
429 static bool inited = false;
434 sg_host_load_plugin_init();
436 simgrid::s4u::Host::on_creation.connect(&on_host_added);