Only report core throttles per core, not per cpu (#836)

* Only report core throttles per core, not per cpu

* Add topology/core_id to the cpu sysfs fixtures

* Add new cpu fixtures to ttar file

* Merge core_id reading and thermal throttle accounting

* Declare core_id

1 files changed, 18 insertions, 5 deletions

diff --git a/collector/cpu_linux.go b/collector/cpu_linux.go
index 4baf0ee..cd18bd9 100644
--- a/collector/cpu_linux.go
+++ b/collector/cpu_linux.go
@@ -21,6 +21,7 @@ import (
         "os"
         "path/filepath"
         "regexp"
+        "strconv"
         "strings"
 
         "github.com/prometheus/client_golang/prometheus"
@@ -70,11 +71,10 @@ func NewCPUCollector() (Collector, error) {
                         "Maximum cpu thread frequency in hertz.",
                         []string{"cpu"}, nil,
                 ),
-                // FIXME: This should be a per core metric, not per cpu!
                 cpuCoreThrottle: prometheus.NewDesc(
                         prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "core_throttles_total"),
                         "Number of times this cpu core has been throttled.",
-                        []string{"cpu"}, nil,
+                        []string{"core"}, nil,
                 ),
                 cpuPackageThrottle: prometheus.NewDesc(
                         prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "package_throttles_total"),
@@ -104,6 +104,8 @@ func (c *cpuCollector) updateCPUfreq(ch chan<- prometheus.Metric) error {
 
         var value uint64
 
+        cpu_core_throttles := make(map[int]uint64)
+
         // cpu loop
         for _, cpu := range cpus {
                 _, cpuName := filepath.Split(cpu)
@@ -134,10 +136,21 @@ func (c *cpuCollector) updateCPUfreq(ch chan<- prometheus.Metric) error {
                         log.Debugf("CPU %v is missing thermal_throttle", cpu)
                         continue
                 }
-                if value, err = readUintFromFile(filepath.Join(cpu, "thermal_throttle", "core_throttle_count")); err != nil {
-                        return err
+
+                if value, err := readUintFromFile(filepath.Join(cpu, "topology/core_id")); err != nil {
+                        log.Debugf("CPU %v is misssing topology/core_id", cpu)
+                } else {
+                        core_id := int(value)
+                        if value, err = readUintFromFile(filepath.Join(cpu, "thermal_throttle", "core_throttle_count")); err != nil {
+                                return err
+                        }
+                        cpu_core_throttles[core_id] = value
                 }
-                ch <- prometheus.MustNewConstMetric(c.cpuCoreThrottle, prometheus.CounterValue, float64(value), cpuNum)
+        }
+
+        // core throttles
+        for core_id, value := range cpu_core_throttles {
+                ch <- prometheus.MustNewConstMetric(c.cpuCoreThrottle, prometheus.CounterValue, float64(value), strconv.Itoa(core_id))
         }
 
         nodes, err := filepath.Glob(sysFilePath("bus/node/devices/node[0-9]*"))