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");
37 simgrid::s4u::Host* host;
42 explicit Governor(simgrid::s4u::Host* ptr) : host(ptr) { init(); }
43 virtual ~Governor() = default;
47 const char* local_sampling_rate_config = host->getProperty("plugin/dvfs/sampling_rate");
48 double global_sampling_rate_config = xbt_cfg_get_double("plugin/dvfs/sampling_rate");
49 if (local_sampling_rate_config != nullptr) {
50 sampling_rate = std::stod(local_sampling_rate_config);
52 sampling_rate = global_sampling_rate_config;
56 virtual void update() = 0;
57 virtual std::string getName() =0 ;
58 double samplingRate() { return sampling_rate; }
61 class Performance : public Governor {
63 explicit Performance(simgrid::s4u::Host* ptr) : Governor(ptr) {}
65 void update() { host->setPstate(0); }
66 std::string getName() { return "Performance"; }
69 class Powersave : public Governor {
71 explicit Powersave(simgrid::s4u::Host* ptr) : Governor(ptr) {}
73 void update() { host->setPstate(host->getPstatesCount() - 1); }
74 std::string getName() { return "Powersave"; }
77 class OnDemand : public Governor {
78 double freq_up_threshold = 0.95;
81 explicit OnDemand(simgrid::s4u::Host* ptr) : Governor(ptr) {}
83 std::string getName() { return "OnDemand"; }
86 double load = sg_host_get_current_load(host);
88 // FIXME I don't like that we multiply with the getCoreCount() just here...
89 if (load*host->getCoreCount() > freq_up_threshold) {
90 host->setPstate(0); /* Run at max. performance! */
91 XBT_INFO("Changed to pstate %f", 0.0);
93 /* The actual implementation uses a formula here: (See Kernel file cpufreq_ondemand.c:158)
95 * freq_next = min_f + load * (max_f - min_f) / 100
97 * So they assume that frequency increases by 100 MHz. We will just use
98 * lowest_pstate - load*pstatesCount()
100 int max_pstate = host->getPstatesCount() - 1;
101 int new_pstate = max_pstate - load * max_pstate;
102 host->setPstate(new_pstate);
104 XBT_DEBUG("Load: %f --> changed to pstate %i", load*host->getCoreCount(), new_pstate);
109 class Conservative : public Governor {
110 double freq_up_threshold = .8;
111 double freq_down_threshold = .2;
114 explicit Conservative(simgrid::s4u::Host* ptr) : Governor(ptr) {}
116 virtual std::string getName() { return "Conservative"; }
117 virtual void update()
119 double load = sg_host_get_current_load(host)*host->getCoreCount();
120 int pstate = host->getPstate();
122 if (load > freq_up_threshold) {
124 host->setPstate(pstate - 1);
125 XBT_INFO("Load: %f > threshold: %f -> increasing performance to pstate %d", load, freq_up_threshold, pstate - 1);
128 XBT_DEBUG("Load: %f > threshold: %f -> but cannot speed up even more, already in highest pstate %d", load, freq_up_threshold, pstate);
131 else if (load < freq_down_threshold) {
132 int max_pstate = host->getPstatesCount() - 1;
133 if (pstate != max_pstate) { // Are we in the slowest pstate already?
134 host->setPstate(pstate + 1);
135 XBT_INFO("Load: %f < threshold: %f -> slowing down to pstate %d", load, freq_down_threshold, pstate + 1);
138 XBT_DEBUG("Load: %f < threshold: %f -> cannot slow down even more, already in slowest pstate %d", load, freq_down_threshold, pstate);
147 static simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> EXTENSION_ID;
149 explicit HostDvfs(simgrid::s4u::Host*);
153 simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> HostDvfs::EXTENSION_ID;
155 HostDvfs::HostDvfs(simgrid::s4u::Host* ptr) {}
157 HostDvfs::~HostDvfs() = default;
161 using simgrid::plugin::HostDvfs;
163 /* **************************** events callback *************************** */
164 static void on_host_added(simgrid::s4u::Host& host)
166 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
169 std::string name = std::string("dvfs-daemon-") + host.getCname();
170 simgrid::s4u::ActorPtr daemon = simgrid::s4u::Actor::createActor(name.c_str(), &host, []() {
172 * This lambda function is the function the actor (daemon) will execute
173 * all the time - in the case of the dvfs plugin, this controls when to
174 * lower/raise the frequency.
176 simgrid::s4u::ActorPtr daemonProc = simgrid::s4u::Actor::self();
178 XBT_DEBUG("DVFS process on %s is a daemon: %d", daemonProc->getHost()->getName().c_str(), daemonProc->isDaemon());
180 std::string dvfs_governor;
181 const char* host_conf = daemonProc->getHost()->getProperty("plugin/dvfs/governor");
182 if (host_conf != nullptr) {
183 dvfs_governor = std::string(daemonProc->getHost()->getProperty("plugin/dvfs/governor"));
184 boost::algorithm::to_lower(dvfs_governor);
186 dvfs_governor = xbt_cfg_get_string("plugin/dvfs/governor");
187 boost::algorithm::to_lower(dvfs_governor);
190 // FIXME This is really ugly. When do we free the governor? Actually, never, because
191 // daemons never stop to run - they will be killed when the simulation is over. :(
192 simgrid::plugin::dvfs::Governor* governor;
193 if (dvfs_governor == "conservative") {
194 governor = new simgrid::plugin::dvfs::Conservative(daemonProc->getHost());
196 else if (dvfs_governor == "ondemand") {
197 governor = new simgrid::plugin::dvfs::OnDemand(daemonProc->getHost());
199 else if (dvfs_governor == "performance") {
200 governor = new simgrid::plugin::dvfs::Performance(daemonProc->getHost());
202 else if (dvfs_governor == "powersave") {
203 governor = new simgrid::plugin::dvfs::Powersave(daemonProc->getHost());
206 XBT_CRITICAL("No governor specified for host %s", daemonProc->getHost()->getCname());
210 // Sleep *before* updating; important for startup (i.e., t = 0).
211 // In the beginning, we want to go with the pstates specified in the platform file
212 // (so we sleep first)
213 simgrid::s4u::this_actor::sleep_for(governor->samplingRate());
215 XBT_DEBUG("Governor (%s) just updated!", governor->getName().c_str());
218 XBT_WARN("I should have never reached this point: daemons should be killed when all regular processes are done");
222 // This call must be placed in this function. Otherweise, the daemonize() call comes too late and
223 // SMPI will take this process as an MPI process!
227 /* **************************** Public interface *************************** */
230 /** \ingroup SURF_plugin_load
231 * \brief Initializes the HostDvfs plugin
232 * \details The HostDvfs plugin provides an API to get the current load of each host.
234 void sg_host_dvfs_plugin_init()
236 if (HostDvfs::EXTENSION_ID.valid())
239 HostDvfs::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostDvfs>();
241 sg_host_load_plugin_init();
243 simgrid::s4u::Host::onCreation.connect(&on_host_added);
244 xbt_cfg_register_double("plugin/dvfs/sampling_rate", 0.1, nullptr,
245 "How often should the dvfs plugin check whether the frequency needs to be changed?");
246 xbt_cfg_register_string("plugin/dvfs/governor", "performance", nullptr,
247 "Which Governor should be used that adapts the CPU frequency?");