cpu_percent return a bunch o 0s

[KaduUlson]

I'm running a python script in Red Hat 7.3.1-5 to log the Memory and CPU usage for each second.

import datetime
import psutil
import pandas as pd

def writeusage(delt) :
    i = 1 
    usageLog = []
    for i in range(delt):
        usageNow = {"Time" : datetime.datetime.now(),
                    "CPU" : psutil.cpu_percent(interval = 1),
                    "MEMu": psutil.virtual_memory().used / (1024.0 ** 3),       
                    "MEMt": psutil.virtual_memory().total / (1024.0 ** 3),       
                    }
        usageLog.append(usageNow)
    return usageLog

dfusage = pd.DataFrame(writeusage(60))

But it returns a lot of 0s for the cpu_percent.
Is that a expected behavior?

    CPU            ...                                   Time
0   0.0            ...             2018-12-10 13:15:18.510315
1   0.0            ...             2018-12-10 13:15:19.512034
2   0.0            ...             2018-12-10 13:15:20.513665
3   0.0            ...             2018-12-10 13:15:21.514604
4   0.0            ...             2018-12-10 13:15:22.516246
5   0.0            ...             2018-12-10 13:15:23.517942
6   0.0            ...             2018-12-10 13:15:24.519579
7   0.0            ...             2018-12-10 13:15:25.521220
8   0.0            ...             2018-12-10 13:15:26.522852
9   0.0            ...             2018-12-10 13:15:27.524489
10  0.0            ...             2018-12-10 13:15:28.526169
11  0.0            ...             2018-12-10 13:15:29.527820
12  0.0            ...             2018-12-10 13:15:30.529541
13  0.0            ...             2018-12-10 13:15:31.531167
14  0.0            ...             2018-12-10 13:15:32.532778
15  1.0            ...             2018-12-10 13:15:33.534429
16  0.0            ...             2018-12-10 13:15:34.536053
17  0.0            ...             2018-12-10 13:15:35.537690
18  0.0            ...             2018-12-10 13:15:36.539335

Thanks in advance.

[giampaolo]

Mmmm I cannot reproduce that.

[bshen-telesign]

This is happening in python3.6 on CentOS 6.9 for me as well. The same code above reproduces it on my machine.

Edit: As a note, I installed from source instead of using a binary wheel.

[Sygyzmundovych]

Try adding percpu=False like psutil.cpu_percent(percpu=False, interval = 1)

[giampaolo]

I'm gonna close this out as outdated. If the problem still occurs please paste the output below and we can reopen

import psutil, time
print(psutil.cpu_times())
stop_at = time.time() + 1
while time.time() < stop_at:
    psutil.cpu_times()
print(psutil.cpu_times())