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() override { host->setPstate(0); }
66 std::string getName() override { return "Performance"; }
69 class Powersave : public Governor {
71 explicit Powersave(simgrid::s4u::Host* ptr) : Governor(ptr) {}
73 void update() override { host->setPstate(host->getPstatesCount() - 1); }
74 std::string getName() override { 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() override { return "OnDemand"; }
84 void update() override
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("Load: %f > threshold: %f --> changed to pstate %i", load * host->getCoreCount(), freq_up_threshold, 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() override { return "Conservative"; }
117 virtual void update() override
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);
130 } else if (load < freq_down_threshold) {
131 int max_pstate = host->getPstatesCount() - 1;
132 if (pstate != max_pstate) { // Are we in the slowest pstate already?
133 host->setPstate(pstate + 1);
134 XBT_INFO("Load: %f < threshold: %f -> slowing down to pstate %d", load, freq_down_threshold, pstate + 1);
137 XBT_DEBUG("Load: %f < threshold: %f -> cannot slow down even more, already in slowest pstate %d", load, freq_down_threshold, pstate);
146 static simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> EXTENSION_ID;
148 explicit HostDvfs(simgrid::s4u::Host*);
152 simgrid::xbt::Extension<simgrid::s4u::Host, HostDvfs> HostDvfs::EXTENSION_ID;
154 HostDvfs::HostDvfs(simgrid::s4u::Host* ptr) {}
156 HostDvfs::~HostDvfs() = default;
160 using simgrid::plugin::HostDvfs;
162 /* **************************** events callback *************************** */
163 static void on_host_added(simgrid::s4u::Host& host)
165 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
168 std::string name = std::string("dvfs-daemon-") + host.getCname();
169 simgrid::s4u::ActorPtr daemon = simgrid::s4u::Actor::createActor(name.c_str(), &host, []() {
171 * This lambda function is the function the actor (daemon) will execute
172 * all the time - in the case of the dvfs plugin, this controls when to
173 * lower/raise the frequency.
175 simgrid::s4u::ActorPtr daemonProc = simgrid::s4u::Actor::self();
177 XBT_DEBUG("DVFS process on %s is a daemon: %d", daemonProc->getHost()->getName().c_str(), daemonProc->isDaemon());
179 std::string dvfs_governor;
180 const char* host_conf = daemonProc->getHost()->getProperty("plugin/dvfs/governor");
181 if (host_conf != nullptr) {
182 dvfs_governor = std::string(daemonProc->getHost()->getProperty("plugin/dvfs/governor"));
183 boost::algorithm::to_lower(dvfs_governor);
185 dvfs_governor = xbt_cfg_get_string("plugin/dvfs/governor");
186 boost::algorithm::to_lower(dvfs_governor);
189 // FIXME This is really ugly. When do we free the governor? Actually, never, because
190 // daemons never stop to run - they will be killed when the simulation is over. :(
191 simgrid::plugin::dvfs::Governor* governor;
192 if (dvfs_governor == "conservative") {
193 governor = new simgrid::plugin::dvfs::Conservative(daemonProc->getHost());
194 } else if (dvfs_governor == "ondemand") {
195 governor = new simgrid::plugin::dvfs::OnDemand(daemonProc->getHost());
196 } else if (dvfs_governor == "performance") {
197 governor = new simgrid::plugin::dvfs::Performance(daemonProc->getHost());
198 } else if (dvfs_governor == "powersave") {
199 governor = new simgrid::plugin::dvfs::Powersave(daemonProc->getHost());
201 XBT_CRITICAL("No governor specified for host %s", daemonProc->getHost()->getCname());
205 // Sleep *before* updating; important for startup (i.e., t = 0).
206 // In the beginning, we want to go with the pstates specified in the platform file
207 // (so we sleep first)
208 simgrid::s4u::this_actor::sleep_for(governor->samplingRate());
210 XBT_DEBUG("Governor (%s) just updated!", governor->getName().c_str());
213 XBT_WARN("I should have never reached this point: daemons should be killed when all regular processes are done");
217 // This call must be placed in this function. Otherweise, the daemonize() call comes too late and
218 // SMPI will take this process as an MPI process!
222 /* **************************** Public interface *************************** */
225 /** \ingroup SURF_plugin_load
226 * \brief Initializes the HostDvfs plugin
227 * \details The HostDvfs plugin provides an API to get the current load of each host.
229 void sg_host_dvfs_plugin_init()
231 if (HostDvfs::EXTENSION_ID.valid())
234 HostDvfs::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostDvfs>();
236 sg_host_load_plugin_init();
238 simgrid::s4u::Host::onCreation.connect(&on_host_added);
239 xbt_cfg_register_double("plugin/dvfs/sampling_rate", 0.1, nullptr,
240 "How often should the dvfs plugin check whether the frequency needs to be changed?");
241 xbt_cfg_register_string("plugin/dvfs/governor", "performance", nullptr,
242 "Which Governor should be used that adapts the CPU frequency?");