1 /* Copyright (c) 2010-2017. 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 "simgrid/simix.hpp"
8 #include "src/plugins/vm/VirtualMachineImpl.hpp"
9 #include "src/surf/cpu_interface.hpp"
11 #include "simgrid/s4u/Engine.hpp"
13 #include <boost/algorithm/string/classification.hpp>
14 #include <boost/algorithm/string/split.hpp>
19 /** @addtogroup plugin_load
21 This plugin makes it very simple for users to obtain the current load for each host.
25 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_plugin_load, surf, "Logging specific to the HostLoad plugin");
32 static simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> EXTENSION_ID;
34 explicit HostLoad(simgrid::s4u::Host* ptr);
37 double getCurrentLoad();
38 double getComputedFlops();
39 double getAverageLoad();
45 simgrid::s4u::Host* host = nullptr;
46 double last_updated = 0;
47 double last_reset = 0;
48 double current_speed = 0;
49 double current_flops = 0;
50 double computed_flops = 0;
52 long theor_max_flops = 0;
53 bool was_prev_idle = true; /* A host is idle at the beginning */
56 simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
58 HostLoad::HostLoad(simgrid::s4u::Host* ptr)
60 , last_updated(surf_get_clock())
61 , last_reset(surf_get_clock())
62 , current_speed(host->getSpeed())
63 , current_flops(host->pimpl_cpu->constraint()->get_usage())
65 , was_prev_idle(current_flops == 0)
69 HostLoad::~HostLoad() = default;
71 void HostLoad::update()
73 double now = surf_get_clock();
74 if (last_updated < now) {
75 /* flops == pstate_speed * cores_being_currently_used */
76 computed_flops += (now - last_updated) * current_flops;
78 /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
79 * number of active cores */
80 current_flops = host->pimpl_cpu->constraint()->get_usage();
83 idle_time += (now - last_updated);
86 theor_max_flops += current_speed * host->getCoreCount() * (now - last_updated);
87 current_speed = host->getSpeed();
89 was_prev_idle = (current_flops == 0);
94 * WARNING: This function does not guarantee that you have the real load at any time;
95 * imagine all actions on your CPU terminate at time t. Your load is then 0. Then
96 * you query the load (still 0) and then another action starts (still at time t!).
97 * This means that the load was never really 0 (because the time didn't advance) but
98 * it will still be reported as 0.
100 * So, use at your own risk.
102 double HostLoad::getCurrentLoad()
104 // We don't need to call update() here because it is called everytime an
105 // action terminates or starts
106 // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
107 return current_flops / static_cast<double>(host->getSpeed() * host->getCoreCount());
111 * Return idle time since last reset
113 double HostLoad::getIdleTime() {
117 double HostLoad::getAverageLoad()
119 return getComputedFlops() / theor_max_flops;
122 double HostLoad::getComputedFlops()
126 return computed_flops;
130 * Resets the counters
132 void HostLoad::reset()
134 last_updated = surf_get_clock();
135 last_reset = surf_get_clock();
139 current_flops = host->pimpl_cpu->constraint()->get_usage();
140 was_prev_idle = (current_flops == 0);
145 using simgrid::plugin::HostLoad;
147 /* **************************** events callback *************************** */
148 /* This callback is fired either when the host changes its state (on/off) or its speed
149 * (because the user changed the pstate, or because of external trace events) */
150 static void onHostChange(simgrid::s4u::Host& host)
152 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
155 host.extension<HostLoad>()->update();
158 /* This callback is called when an action (computation, idle, ...) terminates */
159 static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf::Action::State /*previous*/)
161 for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
162 simgrid::s4u::Host* host = cpu->getHost();
164 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
167 if (host != nullptr) {
168 host->extension<HostLoad>()->update();
173 /* **************************** Public interface *************************** */
176 /** \ingroup plugin_load
177 * \brief Initializes the HostLoad plugin
178 * \details The HostLoad plugin provides an API to get the current load of each host.
180 void sg_host_load_plugin_init()
182 if (HostLoad::EXTENSION_ID.valid())
185 HostLoad::EXTENSION_ID = simgrid::s4u::Host::extension_create<HostLoad>();
187 /* When attaching a callback into a signal, you can use a lambda as follows, or a regular function as done below */
189 simgrid::s4u::Host::onCreation.connect([](simgrid::s4u::Host& host) {
190 if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
192 host.extension_set(new HostLoad(&host));
195 simgrid::surf::CpuAction::onStateChange.connect(&onActionStateChange);
196 simgrid::s4u::Host::onStateChange.connect(&onHostChange);
197 simgrid::s4u::Host::onSpeedChange.connect(&onHostChange);
200 /** @brief Returns the current load of the host passed as argument
202 * See also @ref plugin_load
204 double sg_host_get_current_load(sg_host_t host)
206 xbt_assert(HostLoad::EXTENSION_ID.valid(),
207 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
209 return host->extension<HostLoad>()->getCurrentLoad();
212 /** @brief Returns the current load of the host passed as argument
214 * See also @ref plugin_load
216 double sg_host_get_avg_load(sg_host_t host)
218 xbt_assert(HostLoad::EXTENSION_ID.valid(),
219 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
221 return host->extension<HostLoad>()->getAverageLoad();
224 /** @brief Returns the time this host was idle since the last reset
226 * See also @ref plugin_load
228 double sg_host_get_idle_time(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 return host->extension<HostLoad>()->getIdleTime();
236 double sg_host_get_computed_flops(sg_host_t host)
238 xbt_assert(HostLoad::EXTENSION_ID.valid(),
239 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
241 return host->extension<HostLoad>()->getComputedFlops();
244 void sg_host_load_reset(sg_host_t host)
246 xbt_assert(HostLoad::EXTENSION_ID.valid(),
247 "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
249 host->extension<HostLoad>()->reset();