Early init of procfs (#1315)

Minor change to match naming convention in other collectors.

Initialize the proc or sys FS instance once while initializing
each collector instead of re-creating for each metric update.

Signed-off-by: Paul Gier <pgier@redhat.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/collector/stat_linux.go b/collector/stat_linux.go
index 290205f..13a4b01 100644
--- a/collector/stat_linux.go
+++ b/collector/stat_linux.go
@@ -24,6 +24,7 @@ import (
 )
 
 type statCollector struct {
+        fs           procfs.FS
         intr         *prometheus.Desc
         ctxt         *prometheus.Desc
         forks        *prometheus.Desc
@@ -38,7 +39,12 @@ func init() {
 
 // NewStatCollector returns a new Collector exposing kernel/system statistics.
 func NewStatCollector() (Collector, error) {
+        fs, err := procfs.NewFS(*procPath)
+        if err != nil {
+                return nil, fmt.Errorf("failed to open procfs: %v", err)
+        }
         return &statCollector{
+                fs: fs,
                 intr: prometheus.NewDesc(
                         prometheus.BuildFQName(namespace, "", "intr_total"),
                         "Total number of interrupts serviced.",
@@ -74,11 +80,7 @@ func NewStatCollector() (Collector, error) {
 
 // Update implements Collector and exposes kernel and system statistics.
 func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
-        fs, err := procfs.NewFS(*procPath)
-        if err != nil {
-                return fmt.Errorf("failed to open procfs: %v", err)
-        }
-        stats, err := fs.NewStat()
+        stats, err := c.fs.NewStat()
         if err != nil {
                 return err
         }