double getCurrentLoad();
double getComputedFlops();
double getAverageLoad();
+ double getIdleTime();
void update();
void reset();
simgrid::s4u::Host* host = nullptr;
double last_updated = 0;
double last_reset = 0;
+ double current_speed = 0;
double current_flops = 0;
double computed_flops = 0;
+ double idle_time = 0;
+ double theor_max_flops = 0;
+ bool was_prev_idle = true; /* A host is idle at the beginning */
};
simgrid::xbt::Extension<simgrid::s4u::Host, HostLoad> HostLoad::EXTENSION_ID;
: host(ptr)
, last_updated(surf_get_clock())
, last_reset(surf_get_clock())
+ , current_speed(host->getSpeed())
, current_flops(host->pimpl_cpu->constraint()->get_usage())
+ , theor_max_flops(0)
+ , was_prev_idle(current_flops == 0)
{
}
void HostLoad::update()
{
double now = surf_get_clock();
- if (last_updated < now) {
- /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
- * number of active cores */
- current_flops = host->pimpl_cpu->constraint()->get_usage();
-
- /* flops == pstate_speed * cores_being_currently_used */
- computed_flops += (now - last_updated) * current_flops;
- last_updated = now;
+
+ /* Current flop per second computed by the cpu; current_flops = k * pstate_speed_in_flops, k \in {0, 1, ..., cores}
+ * number of active cores */
+ current_flops = host->pimpl_cpu->constraint()->get_usage();
+
+ /* flops == pstate_speed * cores_being_currently_used */
+ computed_flops += (now - last_updated) * current_flops;
+
+ if (was_prev_idle) {
+ idle_time += (now - last_updated);
}
+
+ theor_max_flops += current_speed * host->getCoreCount() * (now - last_updated);
+ current_speed = host->getSpeed();
+ last_updated = now;
+ was_prev_idle = (current_flops == 0);
}
+/**
+ * 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.
+ *
+ * So, use at your own risk.
+ */
double HostLoad::getCurrentLoad()
{
+ // We don't need to call update() here because it is called everytime 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->getSpeed() * host->getCoreCount());
}
+/**
+ * Return idle time since last reset
+ */
+double HostLoad::getIdleTime() {
+ return idle_time;
+}
+
double HostLoad::getAverageLoad()
{
- return getComputedFlops() / (host->getSpeed() * host->getCoreCount() * (surf_get_clock() - last_reset));
+ if (theor_max_flops == 0) { // Avoid division by 0
+ return 0;
+ }
+
+ return computed_flops / theor_max_flops;
}
double HostLoad::getComputedFlops()
{
- update();
-
return computed_flops;
}
*/
void HostLoad::reset()
{
- last_updated = surf_get_clock();
- last_reset = surf_get_clock();
- computed_flops = 0;
+ last_updated = surf_get_clock();
+ last_reset = surf_get_clock();
+ idle_time = 0;
+ computed_flops = 0;
+ theor_max_flops = 0;
+ current_flops = host->pimpl_cpu->constraint()->get_usage();
+ current_speed = host->getSpeed();
+ was_prev_idle = (current_flops == 0);
}
}
}
return host->extension<HostLoad>()->getCurrentLoad();
}
+/** @brief Returns the current load of the host passed as argument
+ *
+ * See also @ref plugin_load
+ */
+double sg_host_get_avg_load(sg_host_t host)
+{
+ xbt_assert(HostLoad::EXTENSION_ID.valid(),
+ "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
+
+ return host->extension<HostLoad>()->getAverageLoad();
+}
+
+/** @brief Returns the time this host was idle since the last reset
+ *
+ * See also @ref plugin_load
+ */
+double sg_host_get_idle_time(sg_host_t host)
+{
+ xbt_assert(HostLoad::EXTENSION_ID.valid(),
+ "The Load plugin is not active. Please call sg_host_load_plugin_init() during initialization.");
+
+ return host->extension<HostLoad>()->getIdleTime();
+}
+
double sg_host_get_computed_flops(sg_host_t host)
{
xbt_assert(HostLoad::EXTENSION_ID.valid(),