리눅스 데브코스 [4주차 - 2]<프로파일링 툴 사용해보기>

프로파일링 툴 사용해보기

problem1

코드

import threading
import time

def busy_loop():
    count = 0
    while count < 10**8:
        count += 1

threads = []

for _ in range(10):
    t = threading.Thread(target=busy_loop)
    t.start()
    threads.append(t)

for t in threads:
    t.join()

strace 결과

문제점

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problem 2

코드

import os
import mmap

file_size = 10**9  # 1 GB
file_name = "large_file.dat"

with open(file_name, "wb") as f:
    f.seek(file_size - 1)
    f.write(b"\0")

with open(file_name, "r+b") as f:
    mmapped_data = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_WRITE)

    for i in range(0, file_size, 4096):
        mmapped_data[i] = 0

os.remove(file_name)

strace 결과

문제점

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problem 3

코드

import os
import time

def main():
    num_iterations = 3000
    file_name = "test_file.txt"

    # 파일 생성
    with open(file_name, "w") as f:
        f.write("This is a test file for I/O overhead example.\n" * 100000)

    # 캐시 삭제
    os.system("sync; echo 3 > /proc/sys/vm/drop_caches")

    # 파일 읽기 반복
    start_time = time.time()
    for _ in range(num_iterations):
        with open(file_name, "r") as f:
            f.read()
    end_time = time.time()

    print(f"Total time for {num_iterations} iterations: {end_time - start_time:.2f} seconds")

    # 파일 삭제
    os.remove(file_name)

if __name__ == "__main__":
    main()

strace 결과

문제점

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problem 4

코드

import threading
import time

lock = threading.Lock()

def resource_competing_thread():
    for _ in range(100000):
        with lock:
            time.sleep(0.0001)

threads = []

for _ in range(10):
    t = threading.Thread(target=resource_competing_thread)
    t.start()
    threads.append(t)

for t in threads:
    t.join()

strace 결과

문제점

최적화 방법