1 /* Copyright (c) 2010-2021. 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/load.h"
7 #include "src/include/surf/surf.hpp"
8 #include "src/kernel/activity/ExecImpl.hpp"
9 #include "src/plugins/vm/VirtualMachineImpl.hpp"
10 #include <simgrid/s4u.hpp>
12 // Makes sure that this plugin can be activated from the command line with ``--cfg=plugin:host_load``
13 SIMGRID_REGISTER_PLUGIN(host_load, "Cpu load", &sg_host_load_plugin_init)
15 /** @defgroup plugin_host_load Simple plugin that monitors the current load for each host.
18 In addition, this constitutes a good introductory example on how to write a plugin.
19 It attaches an extension to each host to store some data, and places callbacks in the following signals:
21 - :cpp:member:`simgrid::s4u::Host::on_creation`: Attach a new extension to the newly created host.
22 - :cpp:member:`simgrid::s4u::Exec::on_start`: Make note that a new execution started, increasing the load.
23 - :cpp:member:`simgrid::s4u::Exec::on_completion`: Make note that an execution completed, decreasing the load.
24 - :cpp:member:`simgrid::s4u::Host::on_state_change`: Do what is appropriate when the host gets suspended, turned off
26 - :cpp:member:`simgrid::s4u::Host::on_speed_change`: Do what is appropriate when the DVFS is modified.
28 Note that extensions are automatically destroyed when the host gets destroyed.
32 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
37 static const double activity_uninitialized_remaining_cost = -1;
39 /** This class stores the extra data needed by this plugin about a given host
41 * It is stored as an extension of s4u::Host. Such extensions are retrieved by type as follows:
44 * simgrid::s4u::Host* this_host = ???;
45 * this_extension = host->extension<HostLoad>();
48 * If no extension of that type was ever attached to the inspected object, the ``extension<X>()`` template returns
51 * Please refer to the implementation of ``sg_host_load_plugin_init()`` to see the extension objects are attached to
52 * hosts at initialization time.
56 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
58 explicit HostLoad(simgrid::s4u::Host* ptr)
60 , last_updated_(surf_get_clock())
61 , last_reset_(surf_get_clock())
62 , current_speed_(host_->get_speed())
63 , current_flops_(host_->get_load())
67 explicit HostLoad(simgrid::s4u::Host& ptr) = delete;
68 explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
70 double get_current_load() const;
71 /** Get the the average load since last reset(), as a ratio
73 * That's the ratio (amount of flops that were actually computed) / (amount of flops that could have been computed at full speed)
75 double get_average_load() { update(); return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
76 /** Amount of flops computed since last reset() */
77 double get_computed_flops() { update(); return computed_flops_; }
78 /** Return idle time since last reset() */
79 double get_idle_time() { update(); return idle_time_; }
80 /** Return idle time over the whole simulation */
81 double get_total_idle_time() { update(); return total_idle_time_; }
83 void add_activity(simgrid::kernel::activity::ExecImpl* activity);
87 simgrid::s4u::Host* host_ = nullptr;
88 /* Stores all currently ongoing activities (computations) on this machine */
89 std::map<simgrid::kernel::activity::ExecImpl*, /* cost still remaining*/ double> current_activities;
90 double last_updated_ = 0;
91 double last_reset_ = 0;
93 * current_speed each core is running at; we need to store this as the speed
94 * will already have changed once we get notified
96 double current_speed_ = 0;
98 * How many flops are currently used by all the processes running on this
101 double current_flops_ = 0;
102 double computed_flops_ = 0;
103 double idle_time_ = 0;
104 double total_idle_time_ = 0; /* This updated but never gets reset */
105 double theor_max_flops_ = 0;
108 // Create the static field that the extension mechanism needs
109 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
111 void HostLoad::add_activity(simgrid::kernel::activity::ExecImpl* activity)
113 current_activities.insert({activity, activity_uninitialized_remaining_cost});
116 void HostLoad::update()
118 double now = surf_get_clock();
120 // This loop updates the flops that the host executed for the ongoing computations
121 auto iter = begin(current_activities);
122 while (iter != end(current_activities)) {
123 auto& activity = iter->first; // Just an alias
124 auto& remaining_cost_after_last_update = iter->second; // Just an alias
125 auto& action = activity->surf_action_;
126 auto current_iter = iter;
129 if (action != nullptr && action->get_finish_time() != now && activity->state_ == kernel::activity::State::RUNNING) {
130 if (remaining_cost_after_last_update == activity_uninitialized_remaining_cost) {
131 remaining_cost_after_last_update = action->get_cost();
133 double computed_flops_since_last_update = remaining_cost_after_last_update - /*remaining now*/activity->get_remaining();
134 computed_flops_ += computed_flops_since_last_update;
135 remaining_cost_after_last_update = activity->get_remaining();
136 } else if (activity->state_ == kernel::activity::State::DONE) {
137 computed_flops_ += remaining_cost_after_last_update;
138 current_activities.erase(current_iter);
142 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k @in {0, 1, ..., cores-1}
143 * designates number of active cores; will be 0 if CPU is currently idle */
144 current_flops_ = host_->get_load();
146 if (current_flops_ == 0) {
147 idle_time_ += (now - last_updated_);
148 total_idle_time_ += (now - last_updated_);
149 XBT_DEBUG("[%s]: Currently idle -> Added %f seconds to idle time (totaling %fs)", host_->get_cname(), (now - last_updated_), idle_time_);
152 theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
153 current_speed_ = host_->get_speed();
157 /** @brief Get the current load as a ratio = achieved_flops / (core_current_speed * core_amount)
159 * You may also want to check simgrid::s4u::Host::get_load() that simply returns
160 * the achieved flop rate (in flops per seconds), ie the load that a new action arriving on
161 * that host would suffer.
163 * Please note that this function only returns an instantaneous load that may be deceiving
164 * in some scenarios. For example, imagine that an activity terminates at time t, and that
165 * another activity is created on the same host at the exact same timestamp. The load was
166 * never 0 on the simulated machine since the time did not advance between the two events.
167 * But still, if you call this function between the two events (in the simulator course), it
168 * returns 0 although there is no time (in the simulated time) where this value is valid.
170 double HostLoad::get_current_load() const
172 // We don't need to call update() here because it is called every time an action terminates or starts
173 return current_flops_ / (host_->get_speed() * host_->get_core_count());
177 * Resets the counters
179 void HostLoad::reset()
181 last_updated_ = surf_get_clock();
182 last_reset_ = surf_get_clock();
185 theor_max_flops_ = 0;
186 current_flops_ = host_->get_load();
187 current_speed_ = host_->get_speed();
189 } // namespace plugin
190 } // namespace simgrid
192 using simgrid::plugin::HostLoad;
194 /* **************************** events callback *************************** */
195 /* This callback is fired either when the host changes its state (on/off) or its speed
196 * (because the user changed the pstate, or because of external trace events) */
197 static void on_host_change(simgrid::s4u::Host const& host)
199 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
202 host.extension<HostLoad>()->update();
205 /* **************************** Public interface *************************** */
207 /** @brief Initializes the HostLoad plugin
208 * @ingroup plugin_host_load
210 void sg_host_load_plugin_init()
212 if (HostLoad::EXTENSION_ID.valid()) // Don't do the job twice
215 // First register our extension of Hosts properly
216 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
218 // If SimGrid is already initialized, we need to attach an extension to each existing host
219 if (simgrid::s4u::Engine::is_initialized()) {
220 const simgrid::s4u::Engine* e = simgrid::s4u::Engine::get_instance();
221 for (auto& host : e->get_all_hosts()) {
222 host->extension_set(new HostLoad(host));
226 // Make sure that every future host also gets an extension (in case the platform is not loaded yet)
227 simgrid::s4u::Host::on_creation.connect([](simgrid::s4u::Host& host) {
228 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
230 host.extension_set(new HostLoad(&host));
233 simgrid::s4u::Exec::on_start.connect([](simgrid::s4u::Exec const& activity) {
234 if (activity.get_host_number() == 1) { // We only run on one host
235 simgrid::s4u::Host* host = activity.get_host();
236 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
239 xbt_assert(host != nullptr);
240 host->extension<HostLoad>()->add_activity(static_cast<simgrid::kernel::activity::ExecImpl*>(activity.get_impl()));
241 host->extension<HostLoad>()->update(); // If the system was idle until now, we need to update *before*
242 // this computation starts running so we can keep track of the
243 // idle time. (Communication operations don't trigger this hook!)
245 else { // This runs on multiple hosts
246 XBT_WARN("HostLoad plugin currently does not support executions on several hosts");
249 simgrid::s4u::Exec::on_completion.connect([](simgrid::s4u::Exec const& activity) {
250 if (activity.get_host_number() == 1) { // We only run on one host
251 simgrid::s4u::Host* host = activity.get_host();
252 const simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
255 xbt_assert(host != nullptr);
256 host->extension<HostLoad>()->update();
258 else { // This runs on multiple hosts
259 XBT_WARN("HostLoad plugin currently does not support executions on several hosts");
262 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
263 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
266 /** @brief Returns the current load of that host, as a ratio = achieved_flops / (core_current_speed * core_amount)
267 * @ingroup plugin_host_load
269 double sg_host_get_current_load(const_sg_host_t host)
271 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
273 return host->extension<HostLoad>()->get_current_load();
276 /** @brief Returns the current load of that host
277 * @ingroup plugin_host_load
279 double sg_host_get_avg_load(const_sg_host_t host)
281 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
283 return host->extension<HostLoad>()->get_average_load();
286 /** @brief Returns the time this host was idle since the last reset
287 * @ingroup plugin_host_load
289 double sg_host_get_idle_time(const_sg_host_t host)
291 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
293 return host->extension<HostLoad>()->get_idle_time();
296 /** @brief Returns the time this host was idle since the beginning of the simulation
297 * @ingroup plugin_host_load
299 double sg_host_get_total_idle_time(const_sg_host_t host)
301 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
303 return host->extension<HostLoad>()->get_total_idle_time();
306 /** @brief Returns the amount of flops computed by that host since the last reset
307 * @ingroup plugin_host_load
309 double sg_host_get_computed_flops(const_sg_host_t host)
311 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
313 return host->extension<HostLoad>()->get_computed_flops();
316 /** @brief Resets the idle time and flops amount of that host
317 * @ingroup plugin_host_load
319 void sg_host_load_reset(const_sg_host_t host)
321 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
323 host->extension<HostLoad>()->reset();