agent-enviroments/builder/libs/seastar/demos/scheduling_group_demo.cc
2024-09-10 17:06:08 +03:00

187 lines
7.2 KiB
C++

/*
* 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).get();
auto ksg100 = seastar::defer([&] () noexcept { seastar::destroy_scheduling_group(sg100).get(); });
auto sg20 = seastar::create_scheduling_group("sg20", 20).get();
auto ksg20 = seastar::defer([&] () noexcept { seastar::destroy_scheduling_group(sg20).get(); });
auto sg50 = seastar::create_scheduling_group("sg50", 50).get();
auto ksg50 = seastar::defer([&] () noexcept { 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;
});
});
}