1 /* Copyright (c) 2017-2022. 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/s4u.hpp>
8 XBT_LOG_NEW_DEFAULT_CATEGORY(s4u_ptask_multicore, "Messages specific for this s4u example");
10 namespace sg4 = simgrid::s4u;
14 auto e = sg4::Engine::get_instance();
15 std::vector<double> comp(2, 1e9);
16 std::vector<double> comm(4, 0.0);
18 std::vector<sg4::Host*> hosts_diff = {e->host_by_name("MyHost2"), e->host_by_name("MyHost3")};
19 double start_time = sg4::Engine::get_clock();
20 sg4::this_actor::parallel_execute(hosts_diff, comp, comm);
21 XBT_INFO("Computed 2-core activity on two different hosts. Took %g s", e->get_clock() - start_time);
23 // Same host, monocore.
24 std::vector<sg4::Host*> monocore_hosts = {e->host_by_name("MyHost2"), e->host_by_name("MyHost2")};
25 start_time = sg4::Engine::get_clock();
26 sg4::this_actor::parallel_execute(monocore_hosts, comp, comm);
27 XBT_INFO("Computed 2-core activity a 1-core host. Took %g s", e->get_clock() - start_time);
29 // Same host, multicore.
30 std::vector<sg4::Host*> multicore_host = {e->host_by_name("MyHost1"), e->host_by_name("MyHost1")};
31 start_time = sg4::Engine::get_clock();
32 sg4::this_actor::parallel_execute(multicore_host, comp, comm);
33 XBT_INFO("Computed 2-core activity on a 4-core host. Took %g s", e->get_clock() - start_time);
35 // Same host, using too many cores
36 std::vector<double> comp6(6, 1e9);
37 std::vector<double> comm6(36, 0.0);
38 std::vector<sg4::Host*> multicore_overload(6, e->host_by_name("MyHost1"));
39 start_time = sg4::Engine::get_clock();
40 sg4::this_actor::parallel_execute(multicore_overload, comp6, comm6);
41 XBT_INFO("Computed 6-core activity on a 4-core host. Took %g s", e->get_clock() - start_time);
43 // Same host, adding some communication
44 std::vector<double> comm2 = {0, 1E7, 1E7, 0};
45 start_time = sg4::Engine::get_clock();
46 sg4::this_actor::parallel_execute(multicore_host, comp, comm2);
47 XBT_INFO("Computed 2-core activity on a 4-core host with some communication. Took %g s", e->get_clock() - start_time);
49 // See if the multicore execution continues to work after changing pstate
50 XBT_INFO("Switching machine multicore to pstate 1.");
51 e->host_by_name("MyHost1")->set_pstate(1);
52 XBT_INFO("Switching back to pstate 0.");
53 e->host_by_name("MyHost1")->set_pstate(0);
55 start_time = sg4::Engine::get_clock();
56 sg4::this_actor::parallel_execute(multicore_host, comp, comm);
57 XBT_INFO("Computed 2-core activity on a 4-core host. Took %g s", e->get_clock() - start_time);
59 start_time = sg4::Engine::get_clock();
60 sg4::this_actor::parallel_execute(hosts_diff, comp, comm);
61 XBT_INFO("Computed 2-core activity on two different hosts. Took %g s", e->get_clock() - start_time);
63 // Add a background task and change ptask on the fly
64 auto MyHost1 = e->host_by_name("MyHost1");
65 simgrid::s4u::ExecPtr background_task = MyHost1->exec_async(5e9);
66 XBT_INFO("Start a 1-core background task on the 4-core host.");
68 start_time = sg4::Engine::get_clock();
69 sg4::this_actor::parallel_execute(multicore_host, comp, comm);
70 XBT_INFO("Computed 2-core activity on the 4-core host. Took %g s", e->get_clock() - start_time);
71 XBT_INFO("Remaining amount of work for the background task: %.0f%%",
72 100 * background_task->get_remaining_ratio());
74 XBT_INFO("Switching to pstate 1 while background task is still running.");
75 MyHost1->set_pstate(1);
76 start_time = sg4::Engine::get_clock();
77 sg4::this_actor::parallel_execute(multicore_host, comp, comm);
78 XBT_INFO("Computed again the same 2-core activity on it. Took %g s", e->get_clock() - start_time);
80 background_task->wait();
81 XBT_INFO("The background task has ended.");
84 int main(int argc, char* argv[])
86 sg4::Engine e(&argc, argv);
88 xbt_assert(argc == 2, "Usage: %s <platform file>", argv[0]);
90 e.load_platform(argv[1]);
91 sg4::Actor::create("test", e.host_by_name("MyHost1"), runner);
94 XBT_INFO("Simulation done.");