1 /* Copyright (c) 2010-2019. 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
19 Simple plugin that monitors the current load for each host.
21 In addition, this constitutes a good introductory example on how to write a plugin.
22 It attaches an extension to each host to store some data, and places callbacks in the following signals:
24 - :cpp:member:`simgrid::s4u::Host::on_creation`: Attach a new extension to the newly created host.
25 - :cpp:member:`simgrid::s4u::Exec::on_start`: Make note that a new execution started, increasing the load.
26 - :cpp:member:`simgrid::s4u::Exec::on_completion`: Make note that an execution completed, decreasing the load.
27 - :cpp:member:`simgrid::s4u::Host::on_state_change`: Do what is appropriate when the host gets suspended, turned off or similar.
28 - :cpp:member:`simgrid::s4u::Host::on_speed_change`: Do what is appropriate when the DVFS is modified.
30 Note that extensions are automatically destroyed when the host gets destroyed.
34 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
39 static const double activity_uninitialized_remaining_cost = -1;
41 /** This class stores the extra data needed by this plugin about a given host
43 * It is stored as an extension of s4u::Host. Such extensions are retrieved by type as follows:
46 * simgrid::s4u::Host* this_host = ???;
47 * this_extension = host->extension<HostLoad>();
50 * If no extension of that type was ever attached to the inspected object, the ``extension<X>()`` template returns
53 * Please refer to the implementation of ``sg_host_load_plugin_init()`` to see the extension objects are attached to
54 * hosts at initialization time.
58 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
60 explicit HostLoad(simgrid::s4u::Host* ptr)
62 , last_updated_(surf_get_clock())
63 , last_reset_(surf_get_clock())
64 , current_speed_(host_->get_speed())
65 , current_flops_(host_->pimpl_cpu->get_constraint()->get_usage())
69 ~HostLoad() = default;
71 explicit HostLoad(simgrid::s4u::Host& ptr) = delete;
72 explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
74 double get_current_load();
75 /** Get the the average load since last reset(), as a ratio
77 * That's the ratio (amount of flops that were actually computed) / (amount of flops that could have been computed at full speed)
79 double get_average_load() { update(); return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
80 /** Amount of flops computed since last reset() */
81 double get_computed_flops() { update(); return computed_flops_; }
82 /** Return idle time since last reset() */
83 double get_idle_time() { update(); return idle_time_; }
84 /** Return idle time over the whole simulation */
85 double get_total_idle_time() { update(); return total_idle_time_; }
87 void add_activity(simgrid::kernel::activity::ExecImpl* activity);
91 simgrid::s4u::Host* host_ = nullptr;
92 /* Stores all currently ongoing activities (computations) on this machine */
93 std::map<simgrid::kernel::activity::ExecImpl*, /* cost still remaining*/ double> current_activities;
94 double last_updated_ = 0;
95 double last_reset_ = 0;
97 * current_speed each core is running at; we need to store this as the speed
98 * will already have changed once we get notified
100 double current_speed_ = 0;
102 * How many flops are currently used by all the processes running on this
105 double current_flops_ = 0;
106 double computed_flops_ = 0;
107 double idle_time_ = 0;
108 double total_idle_time_ = 0; /* This updated but never gets reset */
109 double theor_max_flops_ = 0;
112 // Create the static field that the extension mechanism needs
113 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
115 void HostLoad::add_activity(simgrid::kernel::activity::ExecImpl* activity)
117 current_activities.insert({activity, activity_uninitialized_remaining_cost});
120 void HostLoad::update()
122 double now = surf_get_clock();
124 // This loop updates the flops that the host executed for the ongoing computations
125 auto iter = begin(current_activities);
126 while (iter != end(current_activities)) {
127 auto& activity = iter->first; // Just an alias
128 auto& remaining_cost_after_last_update = iter->second; // Just an alias
129 auto& action = activity->surf_action_;
130 auto current_iter = iter;
133 if (action != nullptr && action->get_finish_time() != now && activity->state_ == e_smx_state_t::SIMIX_RUNNING) {
134 if (remaining_cost_after_last_update == activity_uninitialized_remaining_cost) {
135 remaining_cost_after_last_update = action->get_cost();
137 double computed_flops_since_last_update = remaining_cost_after_last_update - /*remaining now*/activity->get_remaining();
138 computed_flops_ += computed_flops_since_last_update;
139 remaining_cost_after_last_update = activity->get_remaining();
141 else if (activity->state_ == e_smx_state_t::SIMIX_DONE) {
142 computed_flops_ += remaining_cost_after_last_update;
143 current_activities.erase(current_iter);
147 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k @in {0, 1, ..., cores-1}
148 * designates number of active cores; will be 0 if CPU is currently idle */
149 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
151 if (current_flops_ == 0) {
152 idle_time_ += (now - last_updated_);
153 total_idle_time_ += (now - last_updated_);
154 XBT_DEBUG("[%s]: Currently idle -> Added %f seconds to idle time (totaling %fs)", host_->get_cname(), (now - last_updated_), idle_time_);
157 theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
158 current_speed_ = host_->get_speed();
162 /** @brief Get the current load as a ratio = achieved_flops / (core_current_speed * core_amount)
164 * You may also want to check simgrid::s4u::Host::get_load() that simply returns
165 * the achieved flop rate (in flops per seconds), ie the load that a new action arriving on
166 * that host would suffer.
168 * Please note that this function only returns an instantaneous load that may be deceiving
169 * in some scenarios. For example, imagine that an activity terminates at time t, and that
170 * another activity is created on the same host at the exact same timestamp. The load was
171 * never 0 on the simulated machine since the time did not advance between the two events.
172 * But still, if you call this function between the two events (in the simulator course), it
173 * returns 0 although there is no time (in the simulated time) where this value is valid.
175 double HostLoad::get_current_load()
177 // We don't need to call update() here because it is called every time an action terminates or starts
178 return current_flops_ / (host_->get_speed() * host_->get_core_count());
182 * Resets the counters
184 void HostLoad::reset()
186 last_updated_ = surf_get_clock();
187 last_reset_ = surf_get_clock();
190 theor_max_flops_ = 0;
191 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
192 current_speed_ = host_->get_speed();
194 } // namespace plugin
195 } // namespace simgrid
197 using simgrid::plugin::HostLoad;
199 /* **************************** events callback *************************** */
200 /* This callback is fired either when the host changes its state (on/off) or its speed
201 * (because the user changed the pstate, or because of external trace events) */
202 static void on_host_change(simgrid::s4u::Host const& host)
204 if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
207 host.extension<HostLoad>()->update();
210 /* **************************** Public interface *************************** */
212 /** @brief Initializes the HostLoad plugin
213 * @ingroup plugin_host_load
215 void sg_host_load_plugin_init()
217 if (HostLoad::EXTENSION_ID.valid()) // Don't do the job twice
220 // First register our extension of Hosts properly
221 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
223 // If SimGrid is already initialized, we need to attach an extension to each existing host
224 if (simgrid::s4u::Engine::is_initialized()) {
225 simgrid::s4u::Engine* e = simgrid::s4u::Engine::get_instance();
226 for (auto& host : e->get_all_hosts()) {
227 host->extension_set(new HostLoad(host));
231 // Make sure that every future host also gets an extension (in case the platform is not loaded yet)
232 simgrid::s4u::Host::on_creation.connect([](simgrid::s4u::Host& host) {
233 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
235 host.extension_set(new HostLoad(&host));
238 simgrid::s4u::Exec::on_start.connect([](simgrid::s4u::Actor const&, simgrid::s4u::Exec const& activity) {
239 if (activity.get_host_number() == 1) { // We only run on one host
240 simgrid::s4u::Host* host = activity.get_host();
241 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
244 xbt_assert(host != nullptr);
245 host->extension<HostLoad>()->add_activity(static_cast<simgrid::kernel::activity::ExecImpl*>(activity.get_impl()));
246 host->extension<HostLoad>()->update(); // If the system was idle until now, we need to update *before*
247 // this computation starts running so we can keep track of the
248 // idle time. (Communication operations don't trigger this hook!)
250 else { // This runs on multiple hosts
251 XBT_WARN("HostLoad plugin currently does not support executions on several hosts");
254 simgrid::s4u::Exec::on_completion.connect([](simgrid::s4u::Actor const&, simgrid::s4u::Exec const& activity) {
255 if (activity.get_host_number() == 1) { // We only run on one host
256 simgrid::s4u::Host* host = activity.get_host();
257 simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
260 xbt_assert(host != nullptr);
261 host->extension<HostLoad>()->update();
263 else { // This runs on multiple hosts
264 XBT_WARN("HostLoad plugin currently does not support executions on several hosts");
267 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
268 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
271 /** @brief Returns the current load of that host, as a ratio = achieved_flops / (core_current_speed * core_amount)
272 * @ingroup plugin_host_load
274 double sg_host_get_current_load(sg_host_t host)
276 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
278 return host->extension<HostLoad>()->get_current_load();
281 /** @brief Returns the current load of that host
282 * @ingroup plugin_host_load
284 double sg_host_get_avg_load(sg_host_t host)
286 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
288 return host->extension<HostLoad>()->get_average_load();
291 /** @brief Returns the time this host was idle since the last reset
292 * @ingroup plugin_host_load
294 double sg_host_get_idle_time(sg_host_t host)
296 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
298 return host->extension<HostLoad>()->get_idle_time();
301 /** @brief Returns the time this host was idle since the beginning of the simulation
302 * @ingroup plugin_host_load
304 double sg_host_get_total_idle_time(sg_host_t host)
306 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
308 return host->extension<HostLoad>()->get_total_idle_time();
311 /** @brief Returns the amount of flops computed by that host since the last reset
312 * @ingroup plugin_host_load
314 double sg_host_get_computed_flops(sg_host_t host)
316 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
318 return host->extension<HostLoad>()->get_computed_flops();
321 /** @brief Resets the idle time and flops amount of that host
322 * @ingroup plugin_host_load
324 void sg_host_load_reset(sg_host_t host)
326 xbt_assert(HostLoad::EXTENSION_ID.valid(), "Please sg_host_load_plugin_init() to initialize this plugin.");
328 host->extension<HostLoad>()->reset();