多进程-为什么多进程。管道python2比python3快

我在多处理管道上进行了性能测试，发现python2中的管道比python3快得多。蟒蛇3的速度大约是蟒蛇2的四倍。我担心如此巨大的性能损失。是什么导致了这个问题？下面是我的测试结果

CentOS Linux 7.4.1708版

[root@localhost tests]# python --version
Python 2.7.5
[root@localhost tests]# python test.py pipe
sending 10000 message to pipe cost 0.0198199748993s
sending 100000 message to pipe cost 0.212320804596s
sending 1000000 message to pipe cost 1.94675683975s
[root@localhost tests]# python3 --version
Python 3.6.8
[root@localhost tests]# python3 test.py pipe
sending 10000 message to pipe cost 0.10193729400634766s
sending 100000 message to pipe cost 0.7190062999725342s
sending 1000000 message to pipe cost 6.87559700012207s

视窗10

C:\Users\tests>py -2 --version
Python 2.7.18

C:\Users\tests>py -2 test.py pipe
sending 10000 message to pipe cost 0.121000051498s
sending 100000 message to pipe cost 0.535000085831s
sending 1000000 message to pipe cost 3.50300002098s

C:\Users\tests>py -3 --version
Python 3.7.6

C:\Users\tests>py -3 test.py pipe
sending 10000 message to pipe cost 0.2459118366241455s
sending 100000 message to pipe cost 1.256772518157959s
sending 1000000 message to pipe cost 10.282079935073853s

源代码：

import sys
import time
import multiprocessing


def reader(channel):
    try:
        recv = channel.get
    except AttributeError:
        recv = channel[0].recv
    while True:
        msg = recv()
        if msg is None:
            break


def writer(count, channel):
    try:
        send = channel.put
    except AttributeError:
        send = channel[1].send
    for i in range(0, count):
        send(i)
    send(None)


if __name__ == '__main__':
    arg = sys.argv[1]
    if arg == "pipe":
        channel = multiprocessing.Pipe()
    else:
        channel = multiprocessing.Queue()

    for count in [10 ** 4, 10 ** 5, 10 ** 6]:
        reader_p = multiprocessing.Process(target=reader, args=(channel,))
        reader_p.daemon = True
        reader_p.start()
        start = time.time()
        writer(count, channel)
        reader_p.join()
        print("sending {} message to {} cost {}s".format(count, arg, time.time()-start))

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