psutil.cpu_freq() error in VMs

[liuliqiang]

hello, guys.

I use psutil in a vm build with KVM, installed with Centos 7.2, and using psutil.cpu_freq() to get the cpu frequence, however it does not would and catch following error:

>>> psutil.cpu_freq()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'cpu_freq'

and i review the code for cpu_freq, and found these:https://github.com/giampaolo/psutil/blob/release-5.4.2/psutil/_pslinux.py#L656-L657。

My doubt is why we only get cpu frequence by these two files? how about /proc/cpuinfo, any question for using it?

Thanks for psutil's contribution.

[giampaolo]

/proc/cpuinfo does not provide max and min values. I suppose we may set them to None though, in case these file:

https://github.com/giampaolo/psutil/blob/release-5.4.2/psutil/_pslinux.py#L656-L657%E3%80%82

...are not defined.

[liuliqiang]

yes，it's well, and would you mind i take a pull request for it?

[giampaolo]

Please go for it

On Wed, 27 Dec 2017 at 02:08, Liqiang Lau ***@***.***> wrote: yes，it's well, and would you mind i take a pull request for it? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#1197 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAplLPDd-yWO6mOY-3r6HQK9vHisztSlks5tEZibgaJpZM4RMddT> .

-- Giampaolo - http://grodola.blogspot.com

[giampaolo]

This is now implemented. Closing.

[davidbrochart]

I have a machine where:

• /sys/devices/system/cpu/cpufreq/ exists but is empty.
• /sys/devices/system/cpu/cpu0/ exists but doesn't have cpufreq in it.

Hence we will not fall back to:

psutil/psutil/_pslinux.py

Lines 705 to 716 in c0aba35

	elif os.path.exists("/proc/cpuinfo"):
	def cpu_freq():
	"""Alternate implementation using /proc/cpuinfo.
	min and max frequencies are not available and are set to None.
	"""
	ret = []
	with open_binary('%s/cpuinfo' % get_procfs_path()) as f:
	for line in f:
	if line.lower().startswith(b'cpu mhz'):
	key, value = line.split(b'\t:', 1)
	ret.append(_common.scpufreq(float(value), None, None))
	return ret

[davidbrochart]

I created a PR for this (#1493).