1 /* Copyright (c) 2010, 2012-2018. 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/simix.hpp"
9 #include "src/plugins/vm/VirtualMachineImpl.hpp"
10 #include "src/surf/cpu_interface.hpp"
12 #include <boost/algorithm/string.hpp>
13 #include <boost/algorithm/string/classification.hpp>
14 #include <boost/algorithm/string/split.hpp>
15 #include <simgrid/msg.h>
16 #include <simgrid/s4u/Engine.hpp>
20 #include <xbt/config.hpp>
22 /** @addtogroup SURF_plugin_load
24 This plugin makes it very simple for users to obtain the current load for each host.
28 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_dvfs, surf, "Logging specific to the SURF HostDvfs plugin");
30 static const char* property_sampling_rate = "plugin/dvfs/sampling_rate";
31 static const char* property_governor = "plugin/dvfs/governor";
40 simgrid::s4u::Host* host;
45 explicit Governor(simgrid::s4u::Host* ptr) : host(ptr) { init(); }
46 virtual ~Governor() = default;
50 const char* local_sampling_rate_config = host->getProperty(property_sampling_rate);
51 double global_sampling_rate_config = xbt_cfg_get_double(property_sampling_rate);
52 if (local_sampling_rate_config != nullptr) {
53 sampling_rate = std::stod(local_sampling_rate_config);
55 sampling_rate = global_sampling_rate_config;
59 virtual void update() = 0;
60 virtual std::string getName() = 0;
61 double samplingRate() { return sampling_rate; }
64 class Performance : public Governor {
66 explicit Performance(simgrid::s4u::Host* ptr) : Governor(ptr) {}
68 void update() override { host->setPstate(0); }
69 std::string getName() override { return "Performance"; }
72 class Powersave : public Governor {
74 explicit Powersave(simgrid::s4u::Host* ptr) : Governor(ptr) {}
76 void update() override { host->setPstate(host->getPstatesCount() - 1); }
77 std::string getName() override { return "Powersave"; }
80 class OnDemand : public Governor {
81 double freq_up_threshold = 0.95;
84 explicit OnDemand(simgrid::s4u::Host* ptr) : Governor(ptr) {}
86 std::string getName() override { return "OnDemand"; }
87 void update() override
89 double load = sg_host_get_current_load(host);
91 // FIXME I don't like that we multiply with the getCoreCount() just here...
92 if (load*host->getCoreCount() > freq_up_threshold) {
93 host->setPstate(0); /* Run at max. performance! */
94 XBT_INFO("Load: %f > threshold: %f --> changed to pstate %i", load * host->getCoreCount(), freq_up_threshold, 0);
96 /* The actual implementation uses a formula here: (See Kernel file cpufreq_ondemand.c:158)
98 * freq_next = min_f + load * (max_f - min_f) / 100
100 * So they assume that frequency increases by 100 MHz. We will just use
101 * lowest_pstate - load*pstatesCount()
103 int max_pstate = host->getPstatesCount() - 1;
104 int new_pstate = max_pstate - load * max_pstate;
105 host->setPstate(new_pstate);
107 XBT_DEBUG("Load: %f --> changed to pstate %i", load*host->getCoreCount(), new_pstate);
112 class Conservative : public Governor {
113 double freq_up_threshold = .8;
114 double freq_down_threshold = .2;
117 explicit Conservative(simgrid::s4u::Host* ptr) : Governor(ptr) {}
119 virtual std::string getName() override { return "Conservative"; }
120 virtual void update() override
122 double load = sg_host_get_current_load(host)*host->getCoreCount();
123 int pstate = host->getPstate();
125 if (load > freq_up_threshold) {
127 host->setPstate(pstate - 1);
128 XBT_INFO("Load: %f > threshold: %f -> increasing performance to pstate %d", load, freq_up_threshold, pstate - 1);
131 XBT_DEBUG("Load: %f > threshold: %f -> but cannot speed up even more, already in highest pstate %d", load, freq_up_threshold, pstate);
133 } else if (load < freq_down_threshold) {
134 int max_pstate = host->getPstatesCount() - 1;
135 if (pstate != max_pstate) { // Are we in the slowest pstate already?
136 host->setPstate(pstate + 1);
137 XBT_INFO("Load: %f < threshold: %f -> slowing down to pstate %d", load, freq_down_threshold, pstate + 1);
140 XBT_DEBUG("Load: %f < threshold: %f -> cannot slow down even more, already in slowest pstate %d", load, freq_down_threshold, pstate);
147 * Add this to your host tag:
148 * - <prop id="plugin/dvfs/governor" value="performance" />
150 * Valid values as of now are: performance, powersave, ondemand, conservative
151 * It doesn't matter if you use uppercase or lowercase.
153 * For the sampling rate, use this:
155 * - <prop id="plugin/dvfs/sampling_rate" value="2" />
157 * This will run the update() method of the specified governor every 2 seconds
160 * These properties can also be used within the <config> tag to configure
161 * these values globally. Using them within the <host> will overwrite this
162 * global configuration
166 static simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> EXTENSION_ID;
168 explicit HostDvfs(simgrid::s4u::Host*);
172 simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> HostDvfs::EXTENSION_ID;
174 HostDvfs::HostDvfs(simgrid::s4u::Host* ptr) {}
176 HostDvfs::~HostDvfs() = default;
181 using simgrid::plugin::dvfs::HostDvfs;
183 /* **************************** events callback *************************** */
184 static void on_host_added(simgrid::s4u::Host& host)
186 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
189 std::string name = std::string("dvfs-daemon-") + host.getCname();
190 simgrid::s4u::ActorPtr daemon = simgrid::s4u::Actor::createActor(name.c_str(), &host, []() {
192 * This lambda function is the function the actor (daemon) will execute
193 * all the time - in the case of the dvfs plugin, this controls when to
194 * lower/raise the frequency.
196 simgrid::s4u::ActorPtr daemonProc = simgrid::s4u::Actor::self();
198 XBT_DEBUG("DVFS process on %s is a daemon: %d", daemonProc->getHost()->getName().c_str(), daemonProc->isDaemon());
200 std::string dvfs_governor;
201 const char* host_conf = daemonProc->getHost()->getProperty(property_governor);
202 if (host_conf != nullptr) {
203 dvfs_governor = std::string(daemonProc->getHost()->getProperty(property_governor));
204 boost::algorithm::to_lower(dvfs_governor);
206 dvfs_governor = xbt_cfg_get_string(property_governor);
207 boost::algorithm::to_lower(dvfs_governor);
210 auto governor = [&dvfs_governor, &daemonProc]() {
211 if (dvfs_governor == "conservative") {
212 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
213 new simgrid::plugin::dvfs::Conservative(daemonProc->getHost()));
214 } else if (dvfs_governor == "ondemand") {
215 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
216 new simgrid::plugin::dvfs::OnDemand(daemonProc->getHost()));
217 } else if (dvfs_governor == "performance") {
218 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
219 new simgrid::plugin::dvfs::Performance(daemonProc->getHost()));
220 } else if (dvfs_governor == "powersave") {
221 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
222 new simgrid::plugin::dvfs::Powersave(daemonProc->getHost()));
224 XBT_CRITICAL("No governor specified for host %s, falling back to Performance",
225 daemonProc->getHost()->getCname());
226 return std::unique_ptr<simgrid::plugin::dvfs::Governor>(
227 new simgrid::plugin::dvfs::Performance(daemonProc->getHost()));
232 // Sleep *before* updating; important for startup (i.e., t = 0).
233 // In the beginning, we want to go with the pstates specified in the platform file
234 // (so we sleep first)
235 simgrid::s4u::this_actor::sleep_for(governor->samplingRate());
237 XBT_DEBUG("Governor (%s) just updated!", governor->getName().c_str());
240 XBT_WARN("I should have never reached this point: daemons should be killed when all regular processes are done");
244 // This call must be placed in this function. Otherweise, the daemonize() call comes too late and
245 // SMPI will take this process as an MPI process!
249 /* **************************** Public interface *************************** */
252 /** \ingroup SURF_plugin_load
253 * \brief Initializes the HostDvfs plugin
254 * \details The HostDvfs plugin provides an API to get the current load of each host.
256 void sg_host_dvfs_plugin_init()
258 if (HostDvfs::EXTENSION_ID.valid())
261 HostDvfs::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostDvfs>();
263 sg_host_load_plugin_init();
265 simgrid::s4u::Host::onCreation.connect(&on_host_added);
266 xbt_cfg_register_double(property_sampling_rate, 0.1, nullptr,
267 "How often should the dvfs plugin check whether the frequency needs to be changed?");
268 xbt_cfg_register_string(property_governor, "performance", nullptr,
269 "Which Governor should be used that adapts the CPU frequency?");