1 /* Copyright (c) 2018. 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 <xbt/replay.hpp>
14 #include "src/kernel/activity/ExecImpl.hpp"
15 #include "src/simix/ActorImpl.hpp"
16 #include <simgrid/smpi/loadbalancer/load_balancer.hpp>
18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(plugin_load_balancer, smpi, "Logging specific to the SMPI load balancing plugin");
20 static simgrid::config::Flag<int> cfg_migration_frequency("smpi/plugin/lb/migration-frequency", {"smpi/plugin/lb/migration_frequency"},
21 "After how many calls to the migration function should the migration be actually executed?", 10,
22 [](double val){if (val != 10) sg_load_balancer_plugin_init();});
28 static simgrid::plugin::loadbalancer::LoadBalancer lb;
30 class MigrateParser : public simgrid::smpi::replay::ActionArgParser {
32 double memory_consumption;
33 void parse(simgrid::xbt::ReplayAction& action, std::string name)
35 // The only parameter is the amount of memory used by the current process.
36 CHECK_ACTION_PARAMS(action, 1, 0);
37 memory_consumption = std::stod(action[2]);
41 /* This function simulates what happens when the original application calls
42 * (A)MPI_Migrate. It executes the load balancing heuristics, makes the necessary
43 * migrations and updates the task mapping in the load balancer.
45 class MigrateAction : public simgrid::smpi::replay::ReplayAction<simgrid::smpi::plugin::MigrateParser> {
47 explicit MigrateAction() : ReplayAction("Migrate") {}
48 void kernel(simgrid::xbt::ReplayAction& action)
50 static std::map<simgrid::s4u::ActorPtr, int> migration_counter;
51 static simgrid::s4u::Barrier smpilb_bar(smpi_process_count());
52 simgrid::s4u::Host* cur_host = simgrid::s4u::this_actor::get_host();
53 simgrid::s4u::Host* migrate_to_host;
55 TRACE_migration_call(my_proc_id, NULL);
57 // TODO cheinrich: Why do we need this barrier?
60 static bool was_executed = false;
61 if (not was_executed) {
64 XBT_INFO("RUNNING THE LB");
69 // This barrier is required to ensure that the mapping has been computed and is available
71 was_executed = false; // Must stay behind this barrier so that all processes have passed the if clause
72 migration_counter[simgrid::s4u::Actor::self()]++;
73 if ((migration_counter[simgrid::s4u::Actor::self()] % simgrid::config::get_value<int>(cfg_migration_frequency.get_name())) != 0) {
77 migrate_to_host = lb.get_mapping();
79 if (cur_host != migrate_to_host) { // Origin and dest are not the same -> migrate
80 sg_host_t migration_hosts[2] = {cur_host, migrate_to_host};
81 // Changing this to double[2] ... will cause trouble with parallel_execute, because that fct is trying to call free().
82 double* comp_amount = new double[2]{0, 0};
83 double* comm_amount = new double[4]{0, std::max(args.memory_consumption, 1.0), 0, 0};
85 xbt_os_timer_t timer = smpi_process()->timer();
86 xbt_os_threadtimer_start(timer);
87 simgrid::s4u::this_actor::parallel_execute(2, migration_hosts, comp_amount, comm_amount, -1.0);
88 xbt_os_threadtimer_stop(timer);
89 smpi_execute(xbt_os_timer_elapsed(timer));
91 // Update the process and host mapping in SimGrid.
92 TRACE_smpi_process_change_host(my_proc_id, migrate_to_host);
93 simgrid::s4u::this_actor::migrate(migrate_to_host);
102 /******************************************************************************
103 * Code to include the duration of iterations in the trace. *
104 ******************************************************************************/
106 // FIXME Move declaration
107 XBT_PRIVATE void action_iteration_in(simgrid::xbt::ReplayAction& action);
108 void action_iteration_in(simgrid::xbt::ReplayAction& action)
110 CHECK_ACTION_PARAMS(action, 0, 0)
111 TRACE_Iteration_in(simgrid::s4u::this_actor::get_pid(), nullptr);
114 // FIXME Move declaration
115 XBT_PRIVATE void action_iteration_out(simgrid::xbt::ReplayAction& action);
116 void action_iteration_out(simgrid::xbt::ReplayAction& action)
118 CHECK_ACTION_PARAMS(action, 0, 0)
119 TRACE_Iteration_out(simgrid::s4u::this_actor::get_pid(), nullptr);
125 /** @ingroup plugin_loadbalancer
126 * @brief Initializes the load balancer plugin
127 * @details The load balancer plugin supports several AMPI load balancers that move ranks
128 * around, based on their host's load.
130 void sg_load_balancer_plugin_init()
132 static bool done = false;
135 simgrid::kernel::activity::ExecImpl::on_completion.connect([](simgrid::kernel::activity::ExecImplPtr activity){
136 simgrid::smpi::plugin::lb.record_actor_computation(activity->simcalls_.front()->issuer->iface(), activity->surf_action_->get_cost());
139 xbt_replay_action_register(
140 "migrate", [](simgrid::xbt::ReplayAction& action) { simgrid::smpi::plugin::MigrateAction().execute(action); });
141 xbt_replay_action_register("iteration_in", simgrid::smpi::plugin::action_iteration_in);
142 xbt_replay_action_register("iteration_out", simgrid::smpi::plugin::action_iteration_out);