4 files changed, 50 insertions, 5 deletions
diff --git a/collectors/python.d.plugin/cpufreq/Makefile.inc b/collectors/python.d.plugin/cpufreq/Makefile.inc
new file mode 100644
index 000000000..d6138801d
--- /dev/null
+++ b/collectors/python.d.plugin/cpufreq/Makefile.inc
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# THIS IS NOT A COMPLETE Makefile
+# IT IS INCLUDED BY ITS PARENT'S Makefile.am
+# IT IS REQUIRED TO REFERENCE ALL FILES RELATIVE TO THE PARENT
+
+# install these files
+dist_python_DATA       += cpufreq/cpufreq.chart.py
+dist_pythonconfig_DATA += cpufreq/cpufreq.conf
+
+# do not install these files, but include them in the distribution
+dist_noinst_DATA       += cpufreq/README.md cpufreq/Makefile.inc
+
diff --git a/collectors/python.d.plugin/cpufreq/README.md b/collectors/python.d.plugin/cpufreq/README.md
new file mode 100644
index 000000000..33891d59d
--- /dev/null
+++ b/collectors/python.d.plugin/cpufreq/README.md
@@ -0,0 +1,30 @@
+# cpufreq
+
+This module shows the current CPU frequency as set by the cpufreq kernel
+module.
+
+**Requirement:**
+You need to have `CONFIG_CPU_FREQ` and (optionally) `CONFIG_CPU_FREQ_STAT`
+enabled in your kernel.
+
+This module tries to read from one of two possible locations. On
+initialization, it tries to read the `time_in_state` files provided by
+cpufreq\_stats. If this file does not exist, or doesn't contain valid data, it
+falls back to using the more inaccurate `scaling_cur_freq` file (which only
+represents the **current** CPU frequency, and doesn't account for any state
+changes which happen between updates).
+
+It produces one chart with multiple lines (one line per core).
+
+### configuration
+
+Sample:
+
+```yaml
+sys_dir: "/sys/devices"
+```
+
+If no configuration is given, module will search for cpufreq files in `/sys/devices` directory.
+Directory is also prefixed with `NETDATA_HOST_PREFIX` if specified.
+
+---
diff --git a/python.d/cpufreq.chart.py b/collectors/python.d.plugin/cpufreq/cpufreq.chart.py
index 3abde736c..cbbab6d7f 100644
--- a/python.d/cpufreq.chart.py
+++ b/collectors/python.d.plugin/cpufreq/cpufreq.chart.py
@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 # Description: cpufreq netdata python.d module
-# Author: Pawel Krupa (paulfantom) and Steven Noonan (tycho)
+# Author: Pawel Krupa (paulfantom)
+# Author: Steven Noonan (tycho)
+# SPDX-License-Identifier: GPL-3.0-or-later
 
 import glob
 import os
@@ -17,7 +19,8 @@ CHARTS = {
         'options': [None, 'CPU Clock', 'MHz', 'cpufreq', 'cpufreq.cpufreq', 'line'],
         'lines': [
             # lines are created dynamically in `check()` method
-        ]}
+        ]
+    }
 }
 
 
@@ -92,7 +95,7 @@ class Service(SimpleService):
             self.assignment[cpu]['accurate'] = path
             self.accurate_last[cpu] = {}
 
-        if len(self.assignment) == 0:
+        if not self.assignment:
             self.accurate_exists = False
 
         for path in glob.glob(self.sys_dir + '/system/cpu/cpu*/cpufreq/scaling_cur_freq'):
@@ -102,7 +105,7 @@ class Service(SimpleService):
                 self.assignment[cpu] = {}
             self.assignment[cpu]['inaccurate'] = path
 
-        if len(self.assignment) == 0:
+        if not self.assignment:
             self.error("couldn't find a method to read cpufreq statistics")
             return False
 
@@ -110,4 +113,3 @@ class Service(SimpleService):
             self.definitions[ORDER[0]]['lines'].append([name, name, 'absolute', 1, 1000])
 
         return True
-
diff --git a/conf.d/python.d/cpufreq.conf b/collectors/python.d.plugin/cpufreq/cpufreq.conf
index 0890245d9..0890245d9 100644
--- a/conf.d/python.d/cpufreq.conf
+++ b/collectors/python.d.plugin/cpufreq/cpufreq.conf