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 SIMGRID_REGISTER_PLUGIN(host_load, "Cpu load", &sg_host_load_plugin_init)
13 /** @addtogroup plugin_load
15 This plugin makes it very simple for users to obtain the current load for each host.
19 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
26 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
28 explicit HostLoad(simgrid::s4u::Host* ptr)
30 , last_updated_(surf_get_clock())
31 , last_reset_(surf_get_clock())
32 , current_speed_(host_->get_speed())
33 , current_flops_(host_->pimpl_cpu->get_constraint()->get_usage())
37 ~HostLoad() = default;
39 explicit HostLoad(simgrid::s4u::Host& ptr) = delete;
40 explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
42 double get_current_load();
43 double get_average_load() { update(); return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
44 double get_computed_flops() { update(); return computed_flops_; }
45 double get_idle_time() { update(); return idle_time_; } /** Return idle time since last reset */
46 double get_total_idle_time() { update(); return total_idle_time_; } /** Return idle time over the whole simulation */
51 simgrid::s4u::Host* host_ = nullptr;
52 double last_updated_ = 0;
53 double last_reset_ = 0;
55 * current_speed each core is running at; we need to store this as the speed
56 * will already have changed once we get notified
58 double current_speed_ = 0;
60 * How many flops are currently used by all the processes running on this
63 double current_flops_ = 0;
64 double computed_flops_ = 0;
65 double idle_time_ = 0;
66 double total_idle_time_ = 0; /* This gets never reset */
67 double theor_max_flops_ = 0;
70 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
72 void HostLoad::update()
74 double now = surf_get_clock();
76 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k @in {0, 1, ..., cores-1}
77 * designates number of active cores; will be 0 if CPU is currently idle */
78 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
80 /* flops == pstate_speed * cores_being_currently_used */
81 computed_flops_ += (now - last_updated_) * current_flops_;
83 if (current_flops_ == 0) {
84 idle_time_ += (now - last_updated_);
85 total_idle_time_ += (now - last_updated_);
86 XBT_DEBUG("[%s]: Currently idle -> Added %f seconds to idle time (totaling %fs)", host_->get_cname(), (now - last_updated_), idle_time_);
89 theor_max_flops_ += current_speed_ * host_->get_core_count() * (now - last_updated_);
90 current_speed_ = host_->get_speed();
95 * WARNING: This function does not guarantee that you have the real load at any time imagine all actions on your CPU
96 * terminate at time t. Your load is then 0. Then you query the load (still 0) and then another action starts (still at
97 * time t!). This means that the load was never really 0 (because the time didn't advance) but it will still be reported
100 * So, use at your own risk.
102 double HostLoad::get_current_load()
104 // We don't need to call update() here because it is called every time an action terminates or starts
105 // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
106 return current_flops_ / static_cast<double>(host_->get_speed() * host_->get_core_count());
110 * Resets the counters
112 void HostLoad::reset()
114 last_updated_ = surf_get_clock();
115 last_reset_ = surf_get_clock();
118 theor_max_flops_ = 0;
119 current_flops_ = host_->pimpl_cpu->get_constraint()->get_usage();
120 current_speed_ = host_->get_speed();
122 } // namespace plugin
123 } // namespace simgrid
125 using simgrid::plugin::HostLoad;
127 /* **************************** events callback *************************** */
128 /* This callback is fired either when the host changes its state (on/off) or its speed
129 * (because the user changed the pstate, or because of external trace events) */
130 static void on_host_change(simgrid::s4u::Host& host)
132 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
135 host.extension<HostLoad>()->update();
138 /* This callback is called when an action (computation, idle, ...) terminates */
139 static void on_action_state_change(simgrid::surf::CpuAction* action, simgrid::kernel::resource::Action::State /*previous*/)
141 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
142 simgrid::s4u::Host* host = cpu->get_host();
144 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
147 if (host != nullptr) {
148 host->extension<HostLoad>()->update();
153 /* **************************** Public interface *************************** */
155 /** @ingroup plugin_load
156 * @brief Initializes the HostLoad plugin
157 * @details The HostLoad plugin provides an API to get the current load of each host.
159 void sg_host_load_plugin_init()
161 if (HostLoad::EXTENSION_ID.valid())
164 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
166 if (simgrid::s4u::Engine::is_initialized()) { // If not yet initialized, this would create a new instance
167 // which would cause seg faults...
168 simgrid::s4u::Engine* e = simgrid::s4u::Engine::get_instance();
169 for (auto& host : e->get_all_hosts()) {
170 host->extension_set(new HostLoad(host));
174 /* When attaching a callback into a signal, you can use a lambda as follows, or a regular function as done below */
176 simgrid::s4u::Host::on_creation.connect([](simgrid::s4u::Host& host) {
177 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
179 host.extension_set(new HostLoad(&host));
182 simgrid::surf::CpuAction::on_state_change.connect(&on_action_state_change);
183 simgrid::s4u::Host::on_state_change.connect(&on_host_change);
184 simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
187 /** @brief Returns the current load of the host passed as argument
189 * See also @ref plugin_load
191 double sg_host_get_current_load(sg_host_t host)
193 xbt_assert(HostLoad::EXTENSION_ID.valid(),
194 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
196 return host->extension<HostLoad>()->get_current_load();
199 /** @brief Returns the current load of the host passed as argument
201 * See also @ref plugin_load
203 double sg_host_get_avg_load(sg_host_t host)
205 xbt_assert(HostLoad::EXTENSION_ID.valid(),
206 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
208 return host->extension<HostLoad>()->get_average_load();
211 /** @brief Returns the time this host was idle since the last reset
213 * See also @ref plugin_load
215 double sg_host_get_idle_time(sg_host_t host)
217 xbt_assert(HostLoad::EXTENSION_ID.valid(),
218 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
220 return host->extension<HostLoad>()->get_idle_time();
223 double sg_host_get_total_idle_time(sg_host_t host)
225 xbt_assert(HostLoad::EXTENSION_ID.valid(),
226 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
228 return host->extension<HostLoad>()->get_total_idle_time();
231 double sg_host_get_computed_flops(sg_host_t host)
233 xbt_assert(HostLoad::EXTENSION_ID.valid(),
234 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
236 return host->extension<HostLoad>()->get_computed_flops();
239 void sg_host_load_reset(sg_host_t host)
241 xbt_assert(HostLoad::EXTENSION_ID.valid(),
242 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
244 host->extension<HostLoad>()->reset();