-/* Copyright (c) 2010-2018. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2010-2019. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
explicit HostLoad(simgrid::s4u::Host&& ptr) = delete;
double get_current_load();
+ /** Get the the average load since last reset(), as a ratio
+ *
+ * That's the ratio (amount of flops that were actually computed) / (amount of flops that could have been computed at full speed)
+ */
double get_average_load() { update(); return (theor_max_flops_ == 0) ? 0 : computed_flops_ / theor_max_flops_; };
+ /** Amount of flops computed since last reset() */
double get_computed_flops() { update(); return computed_flops_; }
- double get_idle_time() { update(); return idle_time_; } /** Return idle time since last reset */
- double get_total_idle_time() { update(); return total_idle_time_; } /** Return idle time over the whole simulation */
+ /** Return idle time since last reset() */
+ double get_idle_time() { update(); return idle_time_; }
+ /** Return idle time over the whole simulation */
+ double get_total_idle_time() { update(); return total_idle_time_; }
void update();
void add_activity(simgrid::kernel::activity::ExecImplPtr activity);
void reset();
while (iter != end(current_activities)) {
auto& activity = iter->first; // Just an alias
auto& remaining_cost_after_last_update = iter->second; // Just an alias
+ auto& action = activity->surf_action_;
auto current_iter = iter;
++iter;
- if (activity->surf_action_->get_finish_time() != now && activity->state_ == e_smx_state_t::SIMIX_RUNNING) {
+ if (action != nullptr && action->get_finish_time() != now && activity->state_ == e_smx_state_t::SIMIX_RUNNING) {
if (remaining_cost_after_last_update == activity_uninitialized_remaining_cost) {
- remaining_cost_after_last_update = activity->surf_action_->get_cost();
+ remaining_cost_after_last_update = action->get_cost();
}
double computed_flops_since_last_update = remaining_cost_after_last_update - /*remaining now*/activity->get_remaining();
computed_flops_ += computed_flops_since_last_update;
last_updated_ = now;
}
-/**
- * WARNING: This function does not guarantee that you have the real load at any time imagine all actions on your CPU
- * terminate at time t. Your load is then 0. Then you query the load (still 0) and then another action starts (still at
- * time t!). This means that the load was never really 0 (because the time didn't advance) but it will still be reported
- * as 0.
+/** @brief Get the current load as a ratio = achieved_flops / (core_current_speed * core_amount)
+ *
+ * You may also want to check simgrid::s4u::Host::get_load() that simply returns
+ * the achieved flop rate (in flops per seconds), ie the load that a new action arriving on
+ * that host would suffer.
*
- * So, use at your own risk.
+ * Please note that this function only returns an instantaneous load that may be deceiving
+ * in some scenarios. For example, imagine that an activity terminates at time t, and that
+ * another activity is created on the same host at the exact same timestamp. The load was
+ * never 0 on the simulated machine since the time did not advance between the two events.
+ * But still, if you call this function between the two events (in the simulator course), it
+ * returns 0 although there is no time (in the simulated time) where this value is valid.
*/
double HostLoad::get_current_load()
{
// We don't need to call update() here because it is called every time an action terminates or starts
- // FIXME: Can this happen at the same time? stop -> call to getCurrentLoad, load = 0 -> next action starts?
- return current_flops_ / static_cast<double>(host_->get_speed() * host_->get_core_count());
+ return current_flops_ / (host_->get_speed() * host_->get_core_count());
}
/*
/* **************************** events callback *************************** */
/* This callback is fired either when the host changes its state (on/off) or its speed
* (because the user changed the pstate, or because of external trace events) */
-static void on_host_change(simgrid::s4u::Host& host)
+static void on_host_change(simgrid::s4u::Host const& host)
{
- if (dynamic_cast<simgrid::s4u::VirtualMachine*>(&host)) // Ignore virtual machines
+ if (dynamic_cast<simgrid::s4u::VirtualMachine const*>(&host)) // Ignore virtual machines
return;
host.extension<HostLoad>()->update();
}
-/* This callback is called when an action (computation, idle, ...) terminates */
-static void on_action_state_change(simgrid::surf::CpuAction* action, simgrid::kernel::resource::Action::State /*previous*/)
-{
- for (simgrid::surf::Cpu* const& cpu : action->cpus()) {
- simgrid::s4u::Host* host = cpu->get_host();
-
- if (dynamic_cast<simgrid::s4u::VirtualMachine*>(host)) // Ignore virtual machines
- return;
-
- if (host != nullptr) {
- host->extension<HostLoad>()->update();
- }
- }
-}
-
/* **************************** Public interface *************************** */
-/** @ingroup plugin_load
- * @brief Initializes the HostLoad plugin
+/** @brief Initializes the HostLoad plugin
* @details The HostLoad plugin provides an API to get the current load of each host.
*/
void sg_host_load_plugin_init()
host.extension_set(new HostLoad(&host));
});
- simgrid::kernel::activity::ExecImpl::on_creation.connect([](simgrid::kernel::activity::ExecImplPtr activity){
- if (activity->host_ != nullptr) { // We only run on one host
- simgrid::s4u::Host* host = activity->host_;
- if (dynamic_cast<simgrid::s4u::VirtualMachine*>(activity->host_))
- host = dynamic_cast<simgrid::s4u::VirtualMachine*>(activity->host_)->get_pm();
-
- host->extension<HostLoad>()->add_activity(activity);
+ simgrid::kernel::activity::ExecImpl::on_creation.connect([](simgrid::kernel::activity::ExecImpl& activity) {
+ if (activity.get_host_number() == 1) { // We only run on one host
+ simgrid::s4u::Host* host = activity.get_host();
+ simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
+ if (vm != nullptr)
+ host = vm->get_pm();
+ xbt_assert(host != nullptr);
+ host->extension<HostLoad>()->add_activity(&activity);
host->extension<HostLoad>()->update(); // If the system was idle until now, we need to update *before*
// this computation starts running so we can keep track of the
// idle time. (Communication operations don't trigger this hook!)
XBT_DEBUG("HostLoad plugin currently does not support executions on several hosts");
}
});
- simgrid::kernel::activity::ExecImpl::on_completion.connect([](simgrid::kernel::activity::ExecImplPtr activity){
- if (activity->host_ != nullptr) { // We only run on one host
- simgrid::s4u::Host* host = activity->host_;
- if (dynamic_cast<simgrid::s4u::VirtualMachine*>(activity->host_))
- host = dynamic_cast<simgrid::s4u::VirtualMachine*>(activity->host_)->get_pm();
-
+ simgrid::kernel::activity::ExecImpl::on_completion.connect([](simgrid::kernel::activity::ExecImpl const& activity) {
+ if (activity.get_host_number() == 1) { // We only run on one host
+ simgrid::s4u::Host* host = activity.get_host();
+ simgrid::s4u::VirtualMachine* vm = dynamic_cast<simgrid::s4u::VirtualMachine*>(host);
+ if (vm != nullptr)
+ host = vm->get_pm();
+ xbt_assert(host != nullptr);
host->extension<HostLoad>()->update();
}
else { // This runs on multiple hosts
simgrid::s4u::Host::on_speed_change.connect(&on_host_change);
}
-/** @brief Returns the current load of the host passed as argument
+/** @brief Returns the current load of that host, as a ratio = achieved_flops / (core_current_speed * core_amount)
*
- * See also @ref plugin_load
+ * See simgrid::plugin::HostLoad::get_current_load() for the full documentation.
*/
double sg_host_get_current_load(sg_host_t host)
{
