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/* Copyright (c) 2007-2025. 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. */
/* This is an example of how the bootup and shutdown periods can be modeled
* with SimGrid, taking both the time and overall consumption into account.
*
* The main idea is to augment the platform description to declare fake
* pstate that represent these states. The CPU speed of these state is zero
* (the CPU delivers 0 flop per second when booting) while the energy
* consumption is the one measured on average on the modeled machine.
*
* When you want to bootup the machine, you set it into the pstate encoding
* the boot (3 in this example), and leave it so for the right time using a
* sleep_for(). During that time no other execution can progress since the
* resource speed is set at 0 flop/s in this fake pstate. Once this is over,
* the boot is done and we switch back to the regular pstate. Conversely,
* the fake pstate 4 is used to encode the shutdown delay.
*
* Some people don't like the idea to add fake pstates for the boot time, and
* would like SimGrid to provide a "cleaner" model for that. But the "right"
* model depends on the study you want to conduct. If you want to study the
* instantaneous consumption of a rebooting data center, the model used here
* is not enough since it considers only the average consumption over the boot,
* while the instantaneous consumption changes dramatically. Conversely, a
* model taking the instantaneous changes into account will be very difficult
* to instantiate correctly (which values will you use?), so it's not adapted
* to most studies. At least, fake pstates allow you to do exactly what you
* need for your very study.
*/
#include "simgrid/s4u.hpp"
#include "simgrid/plugins/energy.h"
XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_test, "Messages specific for this example");
namespace sg4 = simgrid::s4u;
static void simulate_bootup(sg4::Host* host)
{
unsigned long previous_pstate = host->get_pstate();
XBT_INFO("Switch to virtual pstate 3, that encodes the 'booting up' state in that platform");
host->set_pstate(3);
XBT_INFO("Actually start the host");
host->turn_on();
XBT_INFO("Wait 150s to simulate the boot time.");
sg4::this_actor::sleep_for(150);
XBT_INFO("The host is now up and running. Switch back to previous pstate %lu", previous_pstate);
host->set_pstate(previous_pstate);
}
static void simulate_shutdown(sg4::Host* host)
{
unsigned long previous_pstate = host->get_pstate();
XBT_INFO("Switch to virtual pstate 4, that encodes the 'shutting down' state in that platform");
host->set_pstate(4);
XBT_INFO("Wait 7 seconds to simulate the shutdown time.");
sg4::this_actor::sleep_for(7);
XBT_INFO("Switch back to previous pstate %lu, that will be used on reboot.", previous_pstate);
host->set_pstate(previous_pstate);
XBT_INFO("Actually shutdown the host");
host->turn_off();
}
static void monitor()
{
sg4::Host* host1 = sg4::Host::by_name("MyHost1");
XBT_INFO("Initial pstate: %lu; Energy dissipated so far:%.0E J", host1->get_pstate(),
sg_host_get_consumed_energy(host1));
XBT_INFO("Sleep for 10 seconds");
sg4::this_actor::sleep_for(10);
XBT_INFO("Done sleeping. Current pstate: %lu; Energy dissipated so far: %.2f J", host1->get_pstate(),
sg_host_get_consumed_energy(host1));
simulate_shutdown(host1);
XBT_INFO("Host1 is now OFF. Current pstate: %lu; Energy dissipated so far: %.2f J", host1->get_pstate(),
sg_host_get_consumed_energy(host1));
XBT_INFO("Sleep for 10 seconds");
sg4::this_actor::sleep_for(10);
XBT_INFO("Done sleeping. Current pstate: %lu; Energy dissipated so far: %.2f J", host1->get_pstate(),
sg_host_get_consumed_energy(host1));
simulate_bootup(host1);
XBT_INFO("Host1 is now ON again. Current pstate: %lu; Energy dissipated so far: %.2f J", host1->get_pstate(),
sg_host_get_consumed_energy(host1));
}
int main(int argc, char* argv[])
{
sg_host_energy_plugin_init();
sg4::Engine e(&argc, argv);
xbt_assert(argc == 2, "Usage: %s platform_file\n\tExample: %s platform.xml\n", argv[0], argv[0]);
e.load_platform(argv[1]);
e.add_actor("Boot Monitor", e.host_by_name("MyHost2"), monitor);
e.run();
XBT_INFO("End of simulation.");
return 0;
}
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