1 /* Copyright (c) 2018-2019. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #include <simgrid/plugins/load_balancer.h>
7 #include <simgrid/s4u.hpp>
8 #include <simgrid/smpi/replay.hpp>
10 #include <src/smpi/include/smpi_comm.hpp>
11 #include <src/smpi/include/smpi_actor.hpp>
12 #include <src/smpi/plugins/ampi/instr_ampi.hpp>
13 #include <src/smpi/plugins/ampi/ampi.hpp>
14 #include <xbt/replay.hpp>
16 #include "src/kernel/activity/ExecImpl.hpp"
17 #include "src/kernel/actor/ActorImpl.hpp"
18 #include "src/smpi/plugins/load_balancer/load_balancer.hpp" // This is not yet ready to be public
20 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(plugin_load_balancer, smpi, "Logging specific to the SMPI load balancing plugin");
22 static simgrid::config::Flag<int> cfg_migration_frequency("smpi/plugin/lb/migration-frequency", {"smpi/plugin/lb/migration_frequency"},
23 "After how many calls to the migration function should the migration be actually executed?", 10,
24 [](double val){if (val != 10) sg_load_balancer_plugin_init();});
30 static simgrid::plugin::loadbalancer::LoadBalancer lb;
32 class MigrateParser : public simgrid::smpi::replay::ActionArgParser {
34 double memory_consumption;
35 void parse(simgrid::xbt::ReplayAction& action, const std::string&)
37 // The only parameter is the amount of memory used by the current process.
38 CHECK_ACTION_PARAMS(action, 1, 0);
39 memory_consumption = std::stod(action[2]);
43 /* This function simulates what happens when the original application calls
44 * (A)MPI_Migrate. It executes the load balancing heuristics, makes the necessary
45 * migrations and updates the task mapping in the load balancer.
47 class MigrateAction : public simgrid::smpi::replay::ReplayAction<simgrid::smpi::plugin::MigrateParser> {
49 explicit MigrateAction() : ReplayAction("Migrate") {}
50 void kernel(simgrid::xbt::ReplayAction&)
52 static std::map<simgrid::s4u::ActorPtr, int> migration_call_counter;
53 static simgrid::s4u::Barrier smpilb_bar(smpi_get_universe_size());
54 simgrid::s4u::Host* cur_host = simgrid::s4u::this_actor::get_host();
55 simgrid::s4u::Host* migrate_to_host;
57 TRACE_migration_call(my_proc_id, nullptr);
59 // We only migrate every "cfg_migration_frequency"-times, not at every call
60 migration_call_counter[simgrid::s4u::Actor::self()]++;
61 if ((migration_call_counter[simgrid::s4u::Actor::self()] % simgrid::config::get_value<int>(cfg_migration_frequency.get_name())) != 0) {
65 // TODO cheinrich: Why do we need this barrier?
68 static bool was_executed = false;
69 if (not was_executed) {
71 XBT_DEBUG("Process %li runs the load balancer", my_proc_id);
77 // This barrier is required to ensure that the mapping has been computed and is available
79 was_executed = false; // Must stay behind this barrier so that all processes have passed the if clause
81 migrate_to_host = lb.get_mapping(simgrid::s4u::Actor::self());
82 if (cur_host != migrate_to_host) { // Origin and dest are not the same -> migrate
83 std::vector<simgrid::s4u::Host*> migration_hosts = {cur_host, migrate_to_host};
84 std::vector<double> comp_amount = {0, 0};
85 std::vector<double> comm_amount = {0, /*must not be 0*/ std::max(args.memory_consumption, 1.0), 0, 0};
87 xbt_os_timer_t timer = smpi_process()->timer();
88 xbt_os_threadtimer_start(timer);
89 simgrid::s4u::this_actor::parallel_execute(migration_hosts, comp_amount, comm_amount, -1.0);
90 xbt_os_threadtimer_stop(timer);
91 smpi_execute(xbt_os_timer_elapsed(timer));
93 // Update the process and host mapping in SimGrid.
94 XBT_DEBUG("Migrating process %li from %s to %s", my_proc_id, cur_host->get_cname(), migrate_to_host->get_cname());
95 TRACE_smpi_process_change_host(my_proc_id, migrate_to_host);
96 simgrid::s4u::this_actor::migrate(migrate_to_host);
105 /******************************************************************************
106 * Code to include the duration of iterations in the trace. *
107 ******************************************************************************/
109 // FIXME Move declaration
110 XBT_PRIVATE void action_iteration_in(simgrid::xbt::ReplayAction& action);
111 void action_iteration_in(simgrid::xbt::ReplayAction& action)
113 CHECK_ACTION_PARAMS(action, 0, 0)
114 TRACE_Iteration_in(simgrid::s4u::this_actor::get_pid(), nullptr);
115 simgrid::smpi::plugin::ampi::on_iteration_in(*MPI_COMM_WORLD->group()->actor(std::stol(action[0])));
118 XBT_PRIVATE void action_iteration_out(simgrid::xbt::ReplayAction& action);
119 void action_iteration_out(simgrid::xbt::ReplayAction& action)
121 CHECK_ACTION_PARAMS(action, 0, 0)
122 TRACE_Iteration_out(simgrid::s4u::this_actor::get_pid(), nullptr);
123 simgrid::smpi::plugin::ampi::on_iteration_out(*MPI_COMM_WORLD->group()->actor(std::stol(action[0])));
129 /** @ingroup plugin_loadbalancer
130 * @brief Initializes the load balancer plugin
131 * @details The load balancer plugin supports several AMPI load balancers that move ranks
132 * around, based on their host's load.
134 void sg_load_balancer_plugin_init()
136 static bool done = false;
139 simgrid::kernel::activity::ExecImpl::on_completion.connect([](simgrid::kernel::activity::ExecImpl const& activity) {
140 simgrid::smpi::plugin::lb.record_actor_computation(activity.simcalls_.front()->issuer_->iface(),
141 activity.surf_action_->get_cost());
144 xbt_replay_action_register(
145 "migrate", [](simgrid::xbt::ReplayAction& action) { simgrid::smpi::plugin::MigrateAction().execute(action); });
146 xbt_replay_action_register("iteration_in", simgrid::smpi::plugin::action_iteration_in);
147 xbt_replay_action_register("iteration_out", simgrid::smpi::plugin::action_iteration_out);