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Diffstat (limited to 'src/seastar/demos/scheduling_group_demo.cc')
| -rw-r--r-- | src/seastar/demos/scheduling_group_demo.cc | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/src/seastar/demos/scheduling_group_demo.cc b/src/seastar/demos/scheduling_group_demo.cc new file mode 100644 index 000000000..8e1314c66 --- /dev/null +++ b/src/seastar/demos/scheduling_group_demo.cc @@ -0,0 +1,186 @@ +/* + * This file is open source software, licensed to you under the terms + * of the Apache License, Version 2.0 (the "License"). See the NOTICE file + * distributed with this work for additional information regarding copyright + * ownership. You may not use this file except in compliance with the License. + * + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +/* + * Copyright (C) 2016 Scylla DB Ltd + */ + + +#include <seastar/core/app-template.hh> +#include <seastar/core/future.hh> +#include <seastar/core/scheduling.hh> +#include <seastar/core/thread.hh> +#include <seastar/core/loop.hh> +#include <seastar/core/when_all.hh> +#include <seastar/core/with_scheduling_group.hh> +#include <seastar/core/condition-variable.hh> +#include <seastar/util/defer.hh> +#include <fmt/printf.h> +#include <chrono> +#include <cmath> +#include <boost/range/irange.hpp> + +using namespace seastar; +using namespace std::chrono_literals; + +template <typename Func, typename Duration> +future<> +compute_intensive_task(Duration duration, unsigned& counter, Func func) { + auto end = std::chrono::steady_clock::now() + duration; + while (std::chrono::steady_clock::now() < end) { + func(); + } + ++counter; + return make_ready_future<>(); +} + +future<> +heavy_task(unsigned& counter) { + return compute_intensive_task(1ms, counter, [] { + static thread_local double x = 1; + x = std::exp(x) / 3; + }); +} + +future<> +light_task(unsigned& counter) { + return compute_intensive_task(100us, counter, [] { + static thread_local double x = 0.1; + x = std::log(x + 1); + }); +} + +future<> +medium_task(unsigned& counter) { + return compute_intensive_task(400us, counter, [] { + static thread_local double x = 0.1; + x = std::cos(x); + }); +} + +using done_func = std::function<bool ()>; + +future<> +run_compute_intensive_tasks(seastar::scheduling_group sg, done_func done, unsigned concurrency, unsigned& counter, std::function<future<> (unsigned& counter)> task) { + return seastar::async([task = std::move(task), sg, concurrency, done, &counter] () mutable { + while (!done()) { + parallel_for_each(boost::irange(0u, concurrency), [task, sg, &counter] (unsigned i) mutable { + return with_scheduling_group(sg, [task, &counter] { + return task(counter); + }); + }).get(); + thread::maybe_yield(); + } + }); +} + +future<> +run_compute_intensive_tasks_in_threads(seastar::scheduling_group sg, done_func done, unsigned concurrency, unsigned& counter, std::function<future<> (unsigned& counter)> task) { + auto attr = seastar::thread_attributes(); + attr.sched_group = sg; + return parallel_for_each(boost::irange(0u, concurrency), [attr, done, &counter, task] (unsigned i) { + return seastar::async(attr, [done, &counter, task] { + while (!done()) { + task(counter).get(); + thread::maybe_yield(); + } + }); + }); +} + +future<> +run_with_duty_cycle(float utilization, std::chrono::steady_clock::duration period, done_func done, std::function<future<> (done_func done)> task) { + return seastar::async([=] { + bool duty_toggle = true; + auto t0 = std::chrono::steady_clock::now(); + condition_variable cv; + timer<> tmr_on([&] { duty_toggle = true; cv.signal(); }); + timer<> tmr_off([&] { duty_toggle = false; }); + tmr_on.arm(t0, period); + tmr_off.arm(t0 + std::chrono::duration_cast<decltype(t0)::duration>(period * utilization), period); + auto combined_done = [&] { + return done() || !duty_toggle; + }; + while (!done()) { + while (!combined_done()) { + task(std::cref(combined_done)).get(); + thread::maybe_yield(); + } + cv.wait([&] { + return done() || duty_toggle; + }).get(); + } + tmr_on.cancel(); + tmr_off.cancel(); + }); +} + +#include <fenv.h> + +template <typename T> +auto var_fn(T& var) { + return [&var] { return var; }; +} + +int main(int ac, char** av) { + app_template app; + return app.run(ac, av, [] { + return seastar::async([] { + auto sg100 = seastar::create_scheduling_group("sg100", 100).get0(); + auto ksg100 = seastar::defer([&] { seastar::destroy_scheduling_group(sg100).get(); }); + auto sg20 = seastar::create_scheduling_group("sg20", 20).get0(); + auto ksg20 = seastar::defer([&] { seastar::destroy_scheduling_group(sg20).get(); }); + auto sg50 = seastar::create_scheduling_group("sg50", 50).get0(); + auto ksg50 = seastar::defer([&] { seastar::destroy_scheduling_group(sg50).get(); }); + + bool done = false; + auto end = timer<>([&done] { + done = true; + }); + + end.arm(10s); + unsigned ctr100 = 0, ctr20 = 0, ctr50 = 0; + fmt::print("running three scheduling groups with 100% duty cycle each:\n"); + when_all( + run_compute_intensive_tasks(sg100, var_fn(done), 5, ctr100, heavy_task), + run_compute_intensive_tasks(sg20, var_fn(done), 3, ctr20, light_task), + run_compute_intensive_tasks_in_threads(sg50, var_fn(done), 2, ctr50, medium_task) + ).get(); + fmt::print("{:10} {:15} {:10} {:12} {:8}\n", "shares", "task_time (us)", "executed", "runtime (ms)", "vruntime"); + fmt::print("{:10d} {:15d} {:10d} {:12d} {:8.2f}\n", 100, 1000, ctr100, ctr100 * 1000 / 1000, ctr100 * 1000 / 1000 / 100.); + fmt::print("{:10d} {:15d} {:10d} {:12d} {:8.2f}\n", 20, 100, ctr20, ctr20 * 100 / 1000, ctr20 * 100 / 1000 / 20.); + fmt::print("{:10d} {:15d} {:10d} {:12d} {:8.2f}\n", 50, 400, ctr50, ctr50 * 400 / 1000, ctr50 * 400 / 1000 / 50.); + fmt::print("\n"); + + fmt::print("running two scheduling groups with 100%/50% duty cycles (period=1s:\n"); + unsigned ctr100_2 = 0, ctr50_2 = 0; + done = false; + end.arm(10s); + when_all( + run_compute_intensive_tasks(sg50, var_fn(done), 5, ctr50_2, heavy_task), + run_with_duty_cycle(0.5, 1s, var_fn(done), [=, &ctr100_2] (done_func done) { + return run_compute_intensive_tasks(sg100, done, 4, ctr100_2, heavy_task); + }) + ).get(); + fmt::print("{:10} {:10} {:15} {:10} {:12} {:8}\n", "shares", "duty", "task_time (us)", "executed", "runtime (ms)", "vruntime"); + fmt::print("{:10d} {:10d} {:15d} {:10d} {:12d} {:8.2f}\n", 100, 50, 1000, ctr100_2, ctr100_2 * 1000 / 1000, ctr100_2 * 1000 / 1000 / 100.); + fmt::print("{:10d} {:10d} {:15d} {:10d} {:12d} {:8.2f}\n", 50, 100, 400, ctr50_2, ctr50_2 * 1000 / 1000, ctr50_2 * 1000 / 1000 / 50.); + + return 0; + }); + }); +} |