collector: publish base units and _total counter names (#2743)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/collector/cpu/AGENTS.md

@@ -28,7 +28,8 @@ Hyper-V guest with 12 logical processors in one processor group.
 - `Interrupts/sec`, `DPCs Queued/sec` and `Clock Interrupts/sec`
   (`PERF_COUNTER_COUNTER`) and `C1/C2/C3 Transitions/sec`,
   `Idle Break Events/sec` (`PERF_COUNTER_BULK_COUNT`) are cumulative counts.
-- `Processor Frequency` is a gauge in MHz (3700 here). `Parking Status` is a
+- `Processor Frequency` is a gauge in MHz (3700 here); the collector multiplies
+  it by 1e6 for `windows_cpu_core_frequency_hertz`. `Parking Status` is a
   gauge, 0 when the processor is not parked. `% Performance Limit` is a gauge
   percentage (100 here). `% C3 Time` and `C3 Transitions/sec` stayed 0 on this
   virtual machine.

internal/collector/cpu/cpu.go

@@ -57,7 +57,7 @@ type Collector struct {
 	clockInterruptsTotal       *prometheus.Desc
 	idleBreakEventsTotal       *prometheus.Desc
 	parkingStatus              *prometheus.Desc
-	processorFrequencyMHz      *prometheus.Desc
+	processorFrequencyHertz    *prometheus.Desc
 	processorPerformance       *prometheus.Desc
 	processorMPerf             *prometheus.Desc
 	processorRTC               *prometheus.Desc
@@ -107,7 +107,7 @@ func (c *Collector) Build(logger *slog.Logger, _ *mi.Session) error {
 		nil,
 	)
 	c.timeTotal = prometheus.NewDesc(
-		prometheus.BuildFQName(types.Namespace, Name, "time_total"),
+		prometheus.BuildFQName(types.Namespace, Name, "time_seconds_total"),
 		"Time that processor spent in different modes (dpc, idle, interrupt, privileged, user)",
 		[]string{"core", "mode"},
 		nil,
@@ -142,9 +142,9 @@ func (c *Collector) Build(logger *slog.Logger, _ *mi.Session) error {
 		[]string{"core"},
 		nil,
 	)
-	c.processorFrequencyMHz = prometheus.NewDesc(
-		prometheus.BuildFQName(types.Namespace, Name, "core_frequency_mhz"),
-		"Core frequency in megahertz",
+	c.processorFrequencyHertz = prometheus.NewDesc(
+		prometheus.BuildFQName(types.Namespace, Name, "core_frequency_hertz"),
+		"Core frequency in hertz",
 		[]string{"core"},
 		nil,
 	)
@@ -321,9 +321,9 @@ func (c *Collector) Collect(ch chan<- prometheus.Metric, _ time.Duration) error
 		)
 
 		ch <- prometheus.MustNewConstMetric(
-			c.processorFrequencyMHz,
+			c.processorFrequencyHertz,
 			prometheus.GaugeValue,
-			coreData.ProcessorFrequencyMHz,
+			coreData.ProcessorFrequencyMHz*1e6,
 			core,
 		)