X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7ef49c428ab0209965a09a36ab28b59789aaa4b5..91393c642a33b6bc34e21bfd2465bdc645264c32:/src/surf/plugins/host_energy.cpp diff --git a/src/surf/plugins/host_energy.cpp b/src/surf/plugins/host_energy.cpp index 3096d22d72..6e102e470e 100644 --- a/src/surf/plugins/host_energy.cpp +++ b/src/surf/plugins/host_energy.cpp @@ -18,16 +18,14 @@ /** @addtogroup plugin_energy - -This is the energy plugin, enabling to account not only for computation time, -but also for the dissipated energy in the simulated platform. -To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(), -and then use MSG_host_get_consumed_energy() to retrieve the consumption of a given host. - -When the host is on, this energy consumption naturally depends on both the -current CPU load and the host energy profile. According to our measurements, -the consumption is somehow linear in the amount of cores at full speed, -with an abnormality when all the cores are idle. The full details are in +This is the energy plugin, enabling to account not only for computation time, but also for the dissipated energy in the +simulated platform. +To activate this plugin, first call sg_host_energy_plugin_init() before your #MSG_init(), and then use +MSG_host_get_consumed_energy() to retrieve the consumption of a given host. + +When the host is on, this energy consumption naturally depends on both the current CPU load and the host energy profile. +According to our measurements, the consumption is somehow linear in the amount of cores at full speed, with an +abnormality when all the cores are idle. The full details are in our scientific paper on that topic. As a result, our energy model takes 4 parameters: @@ -61,15 +59,14 @@ This is enough to compute the consumption as a function of the amount of loaded ### What if a given core is only at load 50%? -This is impossible in SimGrid because we recompute everything each time -that the CPU starts or stops doing something. So if a core is at load 50% over -a period, it means that it is at load 100% half of the time and at load 0% the -rest of the time, and our model holds. +This is impossible in SimGrid because we recompute everything each time that the CPU starts or stops doing something. +So if a core is at load 50% over a period, it means that it is at load 100% half of the time and at load 0% the rest of +the time, and our model holds. ### What if the host has only one core? In this case, the parameters \b OneCore and \b AllCores are obviously the same. -Actually, SimGrid expect an energetic profile formated as 'Idle:Running' for mono-cores hosts. +Actually, SimGrid expect an energetic profile formatted as 'Idle:Running' for mono-cores hosts. If you insist on passing 3 parameters in this case, then you must have the same value for \b OneCore and \b AllCores. \code{.xml} @@ -81,8 +78,7 @@ If you insist on passing 3 parameters in this case, then you must have the same ### How does DVFS interact with the host energy model? -If your host has several DVFS levels (several pstates), then you should -give the energetic profile of each pstate level: +If your host has several DVFS levels (several pstates), then you should give the energetic profile of each pstate level: \code{.xml} @@ -104,14 +100,11 @@ To change the pstate of a given CPU, use the following functions: ### How accurate are these models? -This model cannot be more accurate than your instantiation: -with the default values, your result will not be accurate at all. You can still get -accurate energy prediction, provided that you carefully instantiate the model. -The first step is to ensure that your timing prediction match perfectly. But this -is only the first step of the path, and you really want to read -this paper to see all what you need -to do before you can get accurate energy predictions. - +This model cannot be more accurate than your instantiation: with the default values, your result will not be accurate at +all. You can still get accurate energy prediction, provided that you carefully instantiate the model. +The first step is to ensure that your timing prediction match perfectly. But this is only the first step of the path, +and you really want to read this paper to see all what you need to do +before you can get accurate energy predictions. */ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(surf_energy, surf, "Logging specific to the SURF energy plugin"); @@ -147,11 +140,11 @@ private: std::vector power_range_watts_list; /*< List of (min_power,max_power) pairs corresponding to each cpu pstate */ - /* We need to keep track of what pstate has been used, as we will sometimes - * be notified only *after* a pstate has been used (but we need to update the energy consumption - * with the old pstate!) + /* We need to keep track of what pstate has been used, as we will sometimes be notified only *after* a pstate has been + * used (but we need to update the energy consumption with the old pstate!) */ int pstate = 0; + const int pstate_off = -1; public: double watts_off = 0.0; /*< Consumption when the machine is turned off (shutdown) */ @@ -161,7 +154,7 @@ public: simgrid::xbt::Extension HostEnergy::EXTENSION_ID; -/* Computes the consumption so far. Called lazily on need. */ +/* Computes the consumption so far. Called lazily on need. */ void HostEnergy::update() { double start_time = this->last_updated; @@ -200,7 +193,7 @@ void HostEnergy::update() double previous_energy = this->total_energy; double instantaneous_consumption; - if (this->pstate == -1) // The host was off at the beginning of this time interval + if (this->pstate == pstate_off) // The host was off at the beginning of this time interval instantaneous_consumption = this->watts_off; else instantaneous_consumption = this->getCurrentWattsValue(cpu_load); @@ -219,7 +212,7 @@ void HostEnergy::update() } /* Save data for the upcoming time interval: whether it's on/off and the pstate if it's on */ - this->pstate = host->isOn() ? host->getPstate() : -1; + this->pstate = host->isOn() ? host->getPstate() : pstate_off; } HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host(ptr), last_updated(surf_get_clock()) @@ -228,9 +221,12 @@ HostEnergy::HostEnergy(simgrid::s4u::Host* ptr) : host(ptr), last_updated(surf_g const char* off_power_str = host->getProperty("watt_off"); if (off_power_str != nullptr) { - char* msg = bprintf("Invalid value for property watt_off of host %s: %%s", host->getCname()); - this->watts_off = xbt_str_parse_double(off_power_str, msg); - xbt_free(msg); + try { + this->watts_off = std::stod(std::string(off_power_str)); + } catch (std::invalid_argument& ia) { + throw std::invalid_argument(std::string("Invalid value for property watt_off of host ") + host->getCname() + + ": " + off_power_str); + } } /* watts_off is 0 by default */ } @@ -314,7 +310,7 @@ void HostEnergy::initWattsRangeList() XBT_DEBUG("%s: profile: %s, cores: %d", host->getCname(), all_power_values_str, host->getCoreCount()); int i = 0; - for (auto current_power_values_str : all_power_values) { + for (auto const& current_power_values_str : all_power_values) { /* retrieve the power values associated with the current pstate */ std::vector current_power_values; boost::split(current_power_values, current_power_values_str, boost::is_any_of(":")); @@ -329,7 +325,7 @@ void HostEnergy::initWattsRangeList() } else { // size == 3 xbt_assert((current_power_values.at(1)) == (current_power_values.at(2)), "Power properties incorrectly defined for host %s.\n" - "The energy profile of mono-cores should be formated as 'Idle:FullSpeed' only.\n" + "The energy profile of mono-cores should be formatted as 'Idle:FullSpeed' only.\n" "If you go for a 'Idle:OneCore:AllCores' power profile on mono-cores, then OneCore and AllCores " "must be equal.", host->getCname()); @@ -374,7 +370,7 @@ static void onCreation(simgrid::s4u::Host& host) static void onActionStateChange(simgrid::surf::CpuAction* action, simgrid::surf::Action::State previous) { - for (simgrid::surf::Cpu* cpu : action->cpus()) { + for (simgrid::surf::Cpu* const& cpu : action->cpus()) { simgrid::s4u::Host* host = cpu->getHost(); if (host != nullptr) { @@ -468,7 +464,7 @@ void sg_host_energy_update_all() simgrid::simix::kernelImmediate([]() { std::vector list; simgrid::s4u::Engine::getInstance()->getHostList(&list); - for (auto host : list) + for (auto const& host : list) if (dynamic_cast(host) == nullptr) // Ignore virtual machines host->extension()->update(); });