Update cpufreq metrics collector (#1117)

* Update Linux cpufreq collector to use new procfs library functions.
* Split thermal throttle collection to a separate function.
* Add new required fixtures and repack ttar file.

Signed-off-by: Ben Kochie <superq@gmail.com>

1 files changed, 41 insertions, 27 deletions

diff --git a/collector/cpu_linux.go b/collector/cpu_linux.go
index e2a3122..640873f 100644
--- a/collector/cpu_linux.go
+++ b/collector/cpu_linux.go
@@ -17,14 +17,13 @@ package collector
 
 import (
         "fmt"
-        "os"
         "path/filepath"
         "strconv"
-        "strings"
 
         "github.com/prometheus/client_golang/prometheus"
         "github.com/prometheus/common/log"
         "github.com/prometheus/procfs"
+        "github.com/prometheus/procfs/sysfs"
 )
 
 type cpuCollector struct {
@@ -86,46 +85,61 @@ func (c *cpuCollector) Update(ch chan<- prometheus.Metric) error {
         if err := c.updateCPUfreq(ch); err != nil {
                 return err
         }
+        if err := c.updateThermalThrottle(ch); err != nil {
+                return err
+        }
         return nil
 }
 
 // updateCPUfreq reads /sys/devices/system/cpu/cpu* and expose cpu frequency statistics.
 func (c *cpuCollector) updateCPUfreq(ch chan<- prometheus.Metric) error {
+        fs, err := sysfs.NewFS(*sysPath)
+        if err != nil {
+                return fmt.Errorf("failed to open sysfs: %v", err)
+        }
+
+        cpuFreqs, err := fs.NewSystemCpufreq()
+        if err != nil {
+                return err
+        }
+
+        // sysfs cpufreq values are kHz, thus multiply by 1000 to export base units (hz).
+        // See https://www.kernel.org/doc/Documentation/cpu-freq/user-guide.txt
+        for _, stats := range cpuFreqs {
+                ch <- prometheus.MustNewConstMetric(
+                        c.cpuFreq,
+                        prometheus.GaugeValue,
+                        float64(stats.CurrentFrequency)*1000.0,
+                        stats.Name,
+                )
+                ch <- prometheus.MustNewConstMetric(
+                        c.cpuFreqMin,
+                        prometheus.GaugeValue,
+                        float64(stats.MinimumFrequency)*1000.0,
+                        stats.Name,
+                )
+                ch <- prometheus.MustNewConstMetric(
+                        c.cpuFreqMax,
+                        prometheus.GaugeValue,
+                        float64(stats.MaximumFrequency)*1000.0,
+                        stats.Name,
+                )
+        }
+        return nil
+}
+
+// updateThermalThrottle reads /sys/devices/system/cpu/cpu* and expose thermal throttle statistics.
+func (c *cpuCollector) updateThermalThrottle(ch chan<- prometheus.Metric) error {
         cpus, err := filepath.Glob(sysFilePath("devices/system/cpu/cpu[0-9]*"))
         if err != nil {
                 return err
         }
 
-        var value uint64
         packageThrottles := make(map[uint64]uint64)
         packageCoreThrottles := make(map[uint64]map[uint64]uint64)
 
         // cpu loop
         for _, cpu := range cpus {
-                _, cpuName := filepath.Split(cpu)
-                cpuNum := strings.TrimPrefix(cpuName, "cpu")
-
-                if _, err := os.Stat(filepath.Join(cpu, "cpufreq")); os.IsNotExist(err) {
-                        log.Debugf("CPU %v is missing cpufreq", cpu)
-                } else {
-                        // sysfs cpufreq values are kHz, thus multiply by 1000 to export base units (hz).
-                        // See https://www.kernel.org/doc/Documentation/cpu-freq/user-guide.txt
-                        if value, err = readUintFromFile(filepath.Join(cpu, "cpufreq", "scaling_cur_freq")); err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.cpuFreq, prometheus.GaugeValue, float64(value)*1000.0, cpuNum)
-
-                        if value, err = readUintFromFile(filepath.Join(cpu, "cpufreq", "scaling_min_freq")); err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.cpuFreqMin, prometheus.GaugeValue, float64(value)*1000.0, cpuNum)
-
-                        if value, err = readUintFromFile(filepath.Join(cpu, "cpufreq", "scaling_max_freq")); err != nil {
-                                return err
-                        }
-                        ch <- prometheus.MustNewConstMetric(c.cpuFreqMax, prometheus.GaugeValue, float64(value)*1000.0, cpuNum)
-                }
-
                 // See
                 // https://www.kernel.org/doc/Documentation/x86/topology.txt
                 // https://www.kernel.org/doc/Documentation/cputopology.txt