X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/29a3b2869c0075fc75e8ccc66fc1d9c4c8bf6a85..7415b6acc6794b420f8884de0f73fcb3e020d9c0:/src/plugins/host_load.cpp diff --git a/src/plugins/host_load.cpp b/src/plugins/host_load.cpp index ad42f71b6f..c529ac8067 100644 --- a/src/plugins/host_load.cpp +++ b/src/plugins/host_load.cpp @@ -1,4 +1,4 @@ -/* 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. */ @@ -43,10 +43,17 @@ public: 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(); @@ -121,18 +128,22 @@ void HostLoad::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(host_->get_speed() * host_->get_core_count()); } @@ -165,25 +176,9 @@ static void on_host_change(simgrid::s4u::Host& host) host.extension()->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(host)) // Ignore virtual machines - return; - - if (host != nullptr) { - host->extension()->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() @@ -212,8 +207,9 @@ void sg_host_load_plugin_init() 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(activity->host_)) - host = dynamic_cast(activity->host_)->get_pm(); + simgrid::s4u::VirtualMachine* vm = dynamic_cast(host); + if (vm != nullptr) + host = vm->get_pm(); host->extension()->add_activity(activity); host->extension()->update(); // If the system was idle until now, we need to update *before* @@ -227,8 +223,9 @@ void sg_host_load_plugin_init() 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(activity->host_)) - host = dynamic_cast(activity->host_)->get_pm(); + simgrid::s4u::VirtualMachine* vm = dynamic_cast(host); + if (vm != nullptr) + host = vm->get_pm(); host->extension()->update(); } @@ -240,9 +237,9 @@ void sg_host_load_plugin_init() 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) {