python - cpu_percent(interval=None) 无论间隔值 PYTHON 总是返回 0

Question

无论间隔值如何，代码始终返回 0.0 值。

import psutil
p = psutil.Process()
print p.cpu_percent(interval=1)
print p.cpu_percent(interval=None)

Answer 1

此行为是 documented :

When interval is 0.0 or None compares process times to system CPU times elapsed since last call, returning immediately. That means the first time this is called it will return a meaningless 0.0 value which you are supposed to ignore. In this case is recommended for accuracy that this function be called a second time with at least 0.1 seconds between calls.

还有一条警告不要对单个调用使用 interval=None:

Warning: the first time this function is called with interval = 0.0 or None it will return a meaningless 0.0 value which you are supposed to ignore.

如果使用 interval=None，请确保调用 .cpu_percent 与之前的调用相比。

p = psutil.Process(pid=pid)
p.cpu_percent(interval=None)
for i in range(100):
    usage = p.cpu_percent(interval=None)
    # do other things

代替:

for i in range(100):
    p = psutil.Process(pid=pid)
    p.cpu_percent(interval=None)
    # do other things