1 /* Copyright (c) 2010-2018. 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/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 SIMGRID_REGISTER_PLUGIN(host_load, "Cpu load", &sg_host_load_plugin_init)
14 /** @addtogroup plugin_load
16 This plugin makes it very simple for users to obtain the current load for each host.
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
25 static const double activity_uninitialized_remaining_cost = -1;
29 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
31 explicit HostLoad(simgrid::s4u::Host* ptr)
33 , last_updated_(surf_get_clock())
34 , last_reset_(surf_get_clock())
35 , current_speed_(host_->get_speed())
36 , current_flops_(host_->pimpl_cpu->get_constraint()->get_usage())
40 ~HostLoad() = default;
42 explicit HostLoad(simgrid::s4u::Host& ptr) = delete;
43 explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
45 double get_current_load();
46 double get_average_load() { update(); return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
47 double get_computed_flops() { update(); return computed_flops_; }
48 double get_idle_time() { update(); return idle_time_; } /** Return idle time since last reset */
49 double get_total_idle_time() { update(); return total_idle_time_; } /** Return idle time over the whole simulation */
51 void add_activity(simgrid::kernel::activity::ExecImplPtr activity);
55 simgrid::s4u::Host* host_ = nullptr;
56 /* Stores all currently ongoing activities (computations) on this machine */
57 std::map<simgrid::kernel::activity::ExecImplPtr, /* cost still remaining*/double> current_activities;
58 double last_updated_ = 0;
59 double last_reset_ = 0;
61 * current_speed each core is running at; we need to store this as the speed
62 * will already have changed once we get notified
64 double current_speed_ = 0;
66 * How many flops are currently used by all the processes running on this
69 double current_flops_ = 0;
70 double computed_flops_ = 0;
71 double idle_time_ = 0;
72 double total_idle_time_ = 0; /* This gets never reset */
73 double theor_max_flops_ = 0;
76 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
78 void HostLoad::add_activity(simgrid::kernel::activity::ExecImplPtr activity)
80 current_activities.insert({activity, activity_uninitialized_remaining_cost});
83 void HostLoad::update()
85 double now = surf_get_clock();
87 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k @in {0, 1, ..., cores-1}
88 * designates number of active cores; will be 0 if CPU is currently idle */
89 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
91 /* flops == pstate_speed * cores_being_currently_used */
92 computed_flops_ += (now - last_updated_) * current_flops_;
94 if (current_flops_ == 0) {
95 idle_time_ += (now - last_updated_);
96 total_idle_time_ += (now - last_updated_);
97 XBT_DEBUG("[%s]: Currently idle -> Added %f seconds to idle time (totaling %fs)", host_->get_cname(), (now - last_updated_), idle_time_);
100 theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
101 current_speed_ = host_->get_speed();
106 * WARNING: This function does not guarantee that you have the real load at any time imagine all actions on your CPU
107 * terminate at time t. Your load is then 0. Then you query the load (still 0) and then another action starts (still at
108 * time t!). This means that the load was never really 0 (because the time didn't advance) but it will still be reported
111 * So, use at your own risk.
113 double HostLoad::get_current_load()
115 // We don't need to call update() here because it is called every time an action terminates or starts
116 // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
117 return current_flops_ / static_cast<double>(host_->get_speed() * host_->get_core_count());
121 * Resets the counters
123 void HostLoad::reset()
125 last_updated_ = surf_get_clock();
126 last_reset_ = surf_get_clock();
129 theor_max_flops_ = 0;
130 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
131 current_speed_ = host_->get_speed();
133 } // namespace plugin
134 } // namespace simgrid
136 using simgrid::plugin::HostLoad;
138 /* **************************** events callback *************************** */
139 /* This callback is fired either when the host changes its state (on/off) or its speed
140 * (because the user changed the pstate, or because of external trace events) */
141 static void on_host_change(simgrid::s4u::Host& host)
143 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
146 host.extension<HostLoad>()->update();
149 /* This callback is called when an action (computation, idle, ...) terminates */
150 static void on_action_state_change(simgrid::surf::CpuAction* action, simgrid::kernel::resource::Action::State /*previous*/)
152 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
153 simgrid::s4u::Host* host = cpu->get_host();
155 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
158 if (host != nullptr) {
159 host->extension<HostLoad>()->update();
164 /* **************************** Public interface *************************** */
166 /** @ingroup plugin_load
167 * @brief Initializes the HostLoad plugin
168 * @details The HostLoad plugin provides an API to get the current load of each host.
170 void sg_host_load_plugin_init()
172 if (HostLoad::EXTENSION_ID.valid())
175 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
177 if (simgrid::s4u::Engine::is_initialized()) { // If not yet initialized, this would create a new instance
178 // which would cause seg faults...
179 simgrid::s4u::Engine* e = simgrid::s4u::Engine::get_instance();
180 for (auto& host : e->get_all_hosts()) {
181 host->extension_set(new HostLoad(host));
185 /* When attaching a callback into a signal, you can use a lambda as follows, or a regular function as done below */
187 simgrid::s4u::Host::on_creation.connect([](simgrid::s4u::Host& host) {
188 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
190 host.extension_set(new HostLoad(&host));
193 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
194 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
195 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
198 /** @brief Returns the current load of the host passed as argument
200 * See also @ref plugin_load
202 double sg_host_get_current_load(sg_host_t host)
204 xbt_assert(HostLoad::EXTENSION_ID.valid(),
205 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
207 return host->extension<HostLoad>()->get_current_load();
210 /** @brief Returns the current load of the host passed as argument
212 * See also @ref plugin_load
214 double sg_host_get_avg_load(sg_host_t host)
216 xbt_assert(HostLoad::EXTENSION_ID.valid(),
217 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
219 return host->extension<HostLoad>()->get_average_load();
222 /** @brief Returns the time this host was idle since the last reset
224 * See also @ref plugin_load
226 double sg_host_get_idle_time(sg_host_t host)
228 xbt_assert(HostLoad::EXTENSION_ID.valid(),
229 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
231 return host->extension<HostLoad>()->get_idle_time();
234 double sg_host_get_total_idle_time(sg_host_t host)
236 xbt_assert(HostLoad::EXTENSION_ID.valid(),
237 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
239 return host->extension<HostLoad>()->get_total_idle_time();
242 double sg_host_get_computed_flops(sg_host_t host)
244 xbt_assert(HostLoad::EXTENSION_ID.valid(),
245 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
247 return host->extension<HostLoad>()->get_computed_flops();
250 void sg_host_load_reset(sg_host_t host)
252 xbt_assert(HostLoad::EXTENSION_ID.valid(),
253 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
255 host->extension<HostLoad>()->reset();