我编写了一个程序，通过将列表分成子部分并使用Python中的多处理来添加列表，代码如下：

from concurrent.futures import ProcessPoolExecutor, as_completed
import random
import time
      
def dummyFun(l):
    s=0
    for i in range(0,len(l)):
        s=s+l[i]
    return s

 
def sumaSec(v):
    start=time.time()
    sT=0
    for k in range(0,len(v),10):
        vc=v[k:k+10]
        print ("vector ",vc)
        for item in vc:
            sT=sT+item
        print ("sequential sum result ",sT)
        sT=0
    start1=time.time()
    print ("sequential version time ",start1-start)
    
        
def main():
    workers=5
    vector=random.sample(range(1,101),100)
    print (vector)
    sumaSec(vector)
    dim=10
    sT=0
    for k in range(0,len(vector),dim):
        vc=vector[k:k+dim]
        print (vc)
        for item in vc:
            sT=sT+item
        print ("sub list result ",sT)
        sT=0
        
    chunks=(vector[k:k+dim] for k in range(0,len(vector),10))
    start=time.time()
    with ProcessPoolExecutor(max_workers=workers) as executor:
        futures=[executor.submit(dummyFun,chunk) for chunk in chunks]
    for future in as_completed(futures):
        print (future.result())
    start1=time.time()
    print (start1-start)

if __name__=="__main__":
    main()

问题是，对于顺序版本，我得到的时间为：

0.0009753704071044922

而对于并发版本，我的时间是：

0.10629010200500488

当我把工人的数量减少到2时，我的时间是：

0.08622884750366211

为什么会这样呢？