1 files changed, 148 insertions, 0 deletions
diff --git a/collectors/python.d.plugin/cpuidle/cpuidle.chart.py b/collectors/python.d.plugin/cpuidle/cpuidle.chart.py
new file mode 100644
index 0000000..feac025
--- /dev/null
+++ b/collectors/python.d.plugin/cpuidle/cpuidle.chart.py
@@ -0,0 +1,148 @@
+# -*- coding: utf-8 -*-
+# Description: cpuidle netdata python.d module
+# Author: Steven Noonan (tycho)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import ctypes
+import glob
+import os
+import platform
+
+from bases.FrameworkServices.SimpleService import SimpleService
+
+syscall = ctypes.CDLL('libc.so.6').syscall
+
+# default module values (can be overridden per job in `config`)
+# update_every = 2
+
+
+class Service(SimpleService):
+    def __init__(self, configuration=None, name=None):
+        prefix = os.getenv('NETDATA_HOST_PREFIX', "")
+        if prefix.endswith('/'):
+            prefix = prefix[:-1]
+        self.sys_dir = prefix + "/sys/devices/system/cpu"
+        self.schedstat_path = prefix + "/proc/schedstat"
+        SimpleService.__init__(self, configuration=configuration, name=name)
+        self.order = []
+        self.definitions = {}
+        self.fake_name = 'cpu'
+        self.assignment = {}
+        self.last_schedstat = None
+
+    @staticmethod
+    def __gettid():
+        # This is horrendous. We need the *thread id* (not the *process id*),
+        # but there's no Python standard library way of doing that. If you need
+        # to enable this module on a non-x86 machine type, you'll have to find
+        # the Linux syscall number for gettid() and add it to the dictionary
+        # below.
+        syscalls = {
+            'i386':    224,
+            'x86_64':  186,
+        }
+        if platform.machine() not in syscalls:
+            return None
+        tid = syscall(syscalls[platform.machine()])
+        return tid
+
+    def __wake_cpus(self, cpus):
+        # Requires Python 3.3+. This will "tickle" each CPU to force it to
+        # update its idle counters.
+        if hasattr(os, 'sched_setaffinity'):
+            pid = self.__gettid()
+            save_affinity = os.sched_getaffinity(pid)
+            for idx in cpus:
+                os.sched_setaffinity(pid, [idx])
+                os.sched_getaffinity(pid)
+            os.sched_setaffinity(pid, save_affinity)
+
+    def __read_schedstat(self):
+        cpus = {}
+        for line in open(self.schedstat_path, 'r'):
+            if not line.startswith('cpu'):
+                continue
+            line = line.rstrip().split()
+            cpu = line[0]
+            active_time = line[7]
+            cpus[cpu] = int(active_time) // 1000
+        return cpus
+
+    def _get_data(self):
+        results = {}
+
+        # Use the kernel scheduler stats to determine how much time was spent
+        # in C0 (active).
+        schedstat = self.__read_schedstat()
+
+        # Determine if any of the CPUs are idle. If they are, then we need to
+        # tickle them in order to update their C-state residency statistics.
+        if self.last_schedstat is None:
+            needs_tickle = list(self.assignment.keys())
+        else:
+            needs_tickle = []
+            for cpu, active_time in self.last_schedstat.items():
+                delta = schedstat[cpu] - active_time
+                if delta < 1:
+                    needs_tickle.append(cpu)
+
+        if needs_tickle:
+            # This line is critical for the stats to update. If we don't "tickle"
+            # idle CPUs, then the counters for those CPUs stop counting.
+            self.__wake_cpus([int(cpu[3:]) for cpu in needs_tickle])
+
+            # Re-read schedstat now that we've tickled any idlers.
+            schedstat = self.__read_schedstat()
+
+        self.last_schedstat = schedstat
+
+        for cpu, metrics in self.assignment.items():
+            update_time = schedstat[cpu]
+            results[cpu + '_active_time'] = update_time
+
+            for metric, path in metrics.items():
+                residency = int(open(path, 'r').read())
+                results[metric] = residency
+
+        return results
+
+    def check(self):
+        if self.__gettid() is None:
+            self.error('Cannot get thread ID. Stats would be completely broken.')
+            return False
+
+        for path in sorted(glob.glob(self.sys_dir + '/cpu*/cpuidle/state*/name')):
+            # ['', 'sys', 'devices', 'system', 'cpu', 'cpu0', 'cpuidle', 'state3', 'name']
+            path_elem = path.split('/')
+            cpu = path_elem[-4]
+            state = path_elem[-2]
+            statename = open(path, 'rt').read().rstrip()
+
+            orderid = '%s_cpuidle' % (cpu,)
+            if orderid not in self.definitions:
+                self.order.append(orderid)
+                active_name = '%s_active_time' % (cpu,)
+                self.definitions[orderid] = {
+                    'options': [None, 'C-state residency', 'time%', 'cpuidle', 'cpuidle.cpuidle', 'stacked'],
+                    'lines': [
+                        [active_name, 'C0 (active)', 'percentage-of-incremental-row', 1, 1],
+                    ],
+                }
+                self.assignment[cpu] = {}
+
+            defid = '%s_%s_time' % (orderid, state)
+
+            self.definitions[orderid]['lines'].append(
+                [defid, statename, 'percentage-of-incremental-row', 1, 1]
+            )
+
+            self.assignment[cpu][defid] = '/'.join(path_elem[:-1] + ['time'])
+
+        # Sort order by kernel-specified CPU index
+        self.order.sort(key=lambda x: int(x.split('_')[0][3:]))
+
+        if not self.definitions:
+            self.error("couldn't find cstate stats")
+            return False
+
+        return True