Fix kernel_hung metric naming

README.md

@@ -134,6 +134,7 @@ filesystem | Exposes filesystem statistics, such as disk space used. | Darwin, D
 hwmon | Expose hardware monitoring and sensor data from `/sys/class/hwmon/`. | Linux
 infiniband | Exposes network statistics specific to InfiniBand and Intel OmniPath configurations. | Linux
 ipvs | Exposes IPVS status from `/proc/net/ip_vs` and stats from `/proc/net/ip_vs_stats`. | Linux
+kernel_hung | Exposes number of tasks that have been detected as hung from `/proc/sys/kernel/hung_task_detect_count`. | Linux
 loadavg | Exposes load average. | Darwin, Dragonfly, FreeBSD, Linux, NetBSD, OpenBSD, Solaris
 mdadm | Exposes statistics about devices in `/proc/mdstat` (does nothing if no `/proc/mdstat` present). | Linux
 meminfo | Exposes memory statistics. | Darwin, Dragonfly, FreeBSD, Linux, OpenBSD
@@ -195,7 +196,6 @@ drm | Expose GPU metrics using sysfs / DRM, `amdgpu` is the only driver which ex
 drbd | Exposes Distributed Replicated Block Device statistics (to version 8.4) | Linux
 ethtool | Exposes network interface information and network driver statistics equivalent to `ethtool`, `ethtool -S`, and `ethtool -i`. | Linux
 interrupts | Exposes detailed interrupts statistics. | Linux, OpenBSD
-kernel_hung | Exposes number of tasks that have been detected as hung from `/proc/sys/kernel/hung_task_detect_count`. | Linux
 ksmd | Exposes kernel and system statistics from `/sys/kernel/mm/ksm`. | Linux
 lnstat | Exposes stats from `/proc/net/stat/`. | Linux
 logind | Exposes session counts from [logind](http://www.freedesktop.org/wiki/Software/systemd/logind/). | Linux

collector/fixtures/e2e-64k-page-output.txt

@@ -1924,6 +1924,9 @@ node_ipvs_outgoing_bytes_total 0
 # HELP node_ipvs_outgoing_packets_total The total number of outgoing packets.
 # TYPE node_ipvs_outgoing_packets_total counter
 node_ipvs_outgoing_packets_total 0
+# HELP node_kernel_hung_tasks_total Total number of tasks that have been detected as hung since the system booted.
+# TYPE node_kernel_hung_tasks_total counter
+node_kernel_hung_tasks_total 42
 # HELP node_ksmd_full_scans_total ksmd 'full_scans' file.
 # TYPE node_ksmd_full_scans_total counter
 node_ksmd_full_scans_total 323
@@ -3660,6 +3663,7 @@ node_scrape_collector_success{collector="hwmon"} 1
 node_scrape_collector_success{collector="infiniband"} 1
 node_scrape_collector_success{collector="interrupts"} 1
 node_scrape_collector_success{collector="ipvs"} 1
+node_scrape_collector_success{collector="kernel_hung"} 1
 node_scrape_collector_success{collector="ksmd"} 1
 node_scrape_collector_success{collector="lnstat"} 1
 node_scrape_collector_success{collector="loadavg"} 1

collector/fixtures/e2e-output.txt

@@ -1956,6 +1956,9 @@ node_ipvs_outgoing_bytes_total 0
 # HELP node_ipvs_outgoing_packets_total The total number of outgoing packets.
 # TYPE node_ipvs_outgoing_packets_total counter
 node_ipvs_outgoing_packets_total 0
+# HELP node_kernel_hung_tasks_total Total number of tasks that have been detected as hung since the system booted.
+# TYPE node_kernel_hung_tasks_total counter
+node_kernel_hung_tasks_total 42
 # HELP node_ksmd_full_scans_total ksmd 'full_scans' file.
 # TYPE node_ksmd_full_scans_total counter
 node_ksmd_full_scans_total 323
@@ -3692,6 +3695,7 @@ node_scrape_collector_success{collector="hwmon"} 1
 node_scrape_collector_success{collector="infiniband"} 1
 node_scrape_collector_success{collector="interrupts"} 1
 node_scrape_collector_success{collector="ipvs"} 1
+node_scrape_collector_success{collector="kernel_hung"} 1
 node_scrape_collector_success{collector="ksmd"} 1
 node_scrape_collector_success{collector="lnstat"} 1
 node_scrape_collector_success{collector="loadavg"} 1

collector/fixtures/proc/sys/kernel/hung_task_detect_count

@@ -0,0 +1 @@
+42

collector/kernel_hung_linux.go

@@ -29,7 +29,7 @@ type kernelHungCollector struct {
 }
 
 func init() {
-	registerCollector("kernel_hung", defaultDisabled, NewKernelHungCollector)
+	registerCollector("kernel_hung", defaultEnabled, NewKernelHungCollector)
 }
 
 func NewKernelHungCollector(logger *slog.Logger) (Collector, error) {
@@ -44,8 +44,8 @@ func NewKernelHungCollector(logger *slog.Logger) (Collector, error) {
 }
 
 var (
-	taskDetectCount = prometheus.NewDesc(
-		prometheus.BuildFQName(namespace, "kernel_hung", "task_detect_count"),
+	kernelHungTasks = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "kernel_hung", "tasks_total"),
 		"Total number of tasks that have been detected as hung since the system booted.",
 		nil, nil,
 	)
@@ -57,7 +57,7 @@ func (c *kernelHungCollector) Update(ch chan<- prometheus.Metric) error {
 		return err
 	}
 
-	ch <- prometheus.MustNewConstMetric(taskDetectCount, prometheus.CounterValue, float64(*kernelHung.HungTaskDetectCount))
+	ch <- prometheus.MustNewConstMetric(kernelHungTasks, prometheus.CounterValue, float64(*kernelHung.HungTaskDetectCount))
 
 	return nil
 }

end-to-end-test.sh

@@ -57,6 +57,7 @@ enabled_collectors=$(cat << COLLECTORS
   infiniband
   interrupts
   ipvs
+  kernel_hung
   ksmd
   lnstat
   loadavg