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/plugins/vm/VirtualMachineImpl.hpp"
9 #include <simgrid/s4u.hpp>
11 /** @addtogroup plugin_load
13 This plugin makes it very simple for users to obtain the current load for each host.
17 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
24 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
26 explicit HostLoad(simgrid::s4u::Host* ptr)
28 , last_updated_(surf_get_clock())
29 , last_reset_(surf_get_clock())
30 , current_speed_(host_->get_speed())
31 , current_flops_(host_->pimpl_cpu->get_constraint()->get_usage())
33 , was_prev_idle_(current_flops_ == 0)
36 ~HostLoad() = default;
38 explicit HostLoad(simgrid::s4u::Host& ptr) = delete;
39 explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
41 double get_current_load();
42 double get_average_load() { return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
43 double get_computed_flops() { return computed_flops_; }
44 double get_idle_time() { return idle_time_; } /** Return idle time since last reset */
49 simgrid::s4u::Host* host_ = nullptr;
50 double last_updated_ = 0;
51 double last_reset_ = 0;
53 * current_speed each core is running at right now
55 double current_speed_ = 0;
57 * How many flops are currently used by all the processes running on this
60 double current_flops_ = 0;
61 double computed_flops_ = 0;
62 double idle_time_ = 0;
63 double theor_max_flops_ = 0;
64 bool was_prev_idle_ = true; /* A host is idle at the beginning */
67 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
69 void HostLoad::update()
71 double now = surf_get_clock();
73 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
74 * number of active cores */
75 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
77 /* flops == pstate_speed * cores_being_currently_used */
78 computed_flops_ += (now - last_updated_) * current_flops_;
81 idle_time_ += (now - last_updated_);
84 theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
85 current_speed_ = host_->get_speed();
87 was_prev_idle_ = (current_flops_ == 0);
91 * WARNING: This function does not guarantee that you have the real load at any time imagine all actions on your CPU
92 * terminate at time t. Your load is then 0. Then you query the load (still 0) and then another action starts (still at
93 * time t!). This means that the load was never really 0 (because the time didn't advance) but it will still be reported
96 * So, use at your own risk.
98 double HostLoad::get_current_load()
100 // We don't need to call update() here because it is called every time an action terminates or starts
101 // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
102 return current_flops_ / static_cast<double>(host_->get_speed() * host_->get_core_count());
106 * Resets the counters
108 void HostLoad::reset()
110 last_updated_ = surf_get_clock();
111 last_reset_ = surf_get_clock();
114 theor_max_flops_ = 0;
115 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
116 current_speed_ = host_->get_speed();
117 was_prev_idle_ = (current_flops_ == 0);
119 } // namespace plugin
120 } // namespace simgrid
122 using simgrid::plugin::HostLoad;
124 /* **************************** events callback *************************** */
125 /* This callback is fired either when the host changes its state (on/off) or its speed
126 * (because the user changed the pstate, or because of external trace events) */
127 static void on_host_change(simgrid::s4u::Host& host)
129 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
132 host.extension<HostLoad>()->update();
135 /* This callback is called when an action (computation, idle, ...) terminates */
136 static void on_action_state_change(simgrid::surf::CpuAction* action, simgrid::kernel::resource::Action::State /*previous*/)
138 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
139 simgrid::s4u::Host* host = cpu->get_host();
141 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
144 if (host != nullptr) {
145 host->extension<HostLoad>()->update();
150 /* **************************** Public interface *************************** */
152 /** \ingroup plugin_load
153 * \brief Initializes the HostLoad plugin
154 * \details The HostLoad plugin provides an API to get the current load of each host.
156 void sg_host_load_plugin_init()
158 if (HostLoad::EXTENSION_ID.valid())
161 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
163 if (simgrid::s4u::Engine::is_initialized()) { // If not yet initialized, this would create a new instance
164 // which would cause seg faults...
165 simgrid::s4u::Engine* e = simgrid::s4u::Engine::get_instance();
166 for (auto& host : e->get_all_hosts()) {
167 host->extension_set(new HostLoad(host));
171 /* When attaching a callback into a signal, you can use a lambda as follows, or a regular function as done below */
173 simgrid::s4u::Host::on_creation.connect([](simgrid::s4u::Host& host) {
174 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
176 host.extension_set(new HostLoad(&host));
179 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
180 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
181 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
184 /** @brief Returns the current load of the host passed as argument
186 * See also @ref plugin_load
188 double sg_host_get_current_load(sg_host_t host)
190 xbt_assert(HostLoad::EXTENSION_ID.valid(),
191 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
193 return host->extension<HostLoad>()->get_current_load();
196 /** @brief Returns the current load of the host passed as argument
198 * See also @ref plugin_load
200 double sg_host_get_avg_load(sg_host_t host)
202 xbt_assert(HostLoad::EXTENSION_ID.valid(),
203 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
205 return host->extension<HostLoad>()->get_average_load();
208 /** @brief Returns the time this host was idle since the last reset
210 * See also @ref plugin_load
212 double sg_host_get_idle_time(sg_host_t host)
214 xbt_assert(HostLoad::EXTENSION_ID.valid(),
215 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
217 return host->extension<HostLoad>()->get_idle_time();
220 double sg_host_get_computed_flops(sg_host_t host)
222 xbt_assert(HostLoad::EXTENSION_ID.valid(),
223 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
225 return host->extension<HostLoad>()->get_computed_flops();
228 void sg_host_load_reset(sg_host_t host)
230 xbt_assert(HostLoad::EXTENSION_ID.valid(),
231 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
233 host->extension<HostLoad>()->reset();