fix scaler

godeltaprof/block.go

@@ -27,7 +27,7 @@ type BlockProfiler struct {
 	impl           pprof.DeltaMutexProfiler
 	mutex          sync.Mutex
 	runtimeProfile func([]runtime.BlockProfileRecord) (int, bool)
-	scaleProfile   func(int64, float64) (int64, float64)
+	scaleProfile   pprof.MutexProfileScaler
 }
 
 // NewMutexProfiler creates a new BlockProfiler instance for profiling mutex contention.
@@ -39,7 +39,7 @@ type BlockProfiler struct {
 //	    ...
 //	    err := mp.Profile(someWriter)
 func NewMutexProfiler() *BlockProfiler {
-	return &BlockProfiler{runtimeProfile: runtime.MutexProfile, scaleProfile: scaleMutexProfile}
+	return &BlockProfiler{runtimeProfile: runtime.MutexProfile, scaleProfile: pprof.ScalerMutexProfile}
 }
 
 // NewBlockProfiler creates a new BlockProfiler instance for profiling goroutine blocking events.
@@ -51,7 +51,7 @@ func NewMutexProfiler() *BlockProfiler {
 //	...
 //	err := bp.Profile(someWriter)
 func NewBlockProfiler() *BlockProfiler {
-	return &BlockProfiler{runtimeProfile: runtime.BlockProfile, scaleProfile: scaleBlockProfile}
+	return &BlockProfiler{runtimeProfile: runtime.BlockProfile, scaleProfile: pprof.ScalerBlockProfile}
 }
 
 func (d *BlockProfiler) Profile(w io.Writer) error {
@@ -73,16 +73,3 @@ func (d *BlockProfiler) Profile(w io.Writer) error {
 
 	return d.impl.PrintCountCycleProfile(w, "contentions", "delay", d.scaleProfile, p)
 }
-
-func scaleMutexProfile(cnt int64, ns float64) (int64, float64) {
-	period := runtime.SetMutexProfileFraction(-1)
-	return cnt * int64(period), ns * float64(period)
-}
-
-func scaleBlockProfile(cnt int64, ns float64) (int64, float64) {
-	// Do nothing.
-	// The current way of block profile sampling makes it
-	// hard to compute the unsampled number. The legacy block
-	// profile parse doesn't attempt to scale or unsample.
-	return cnt, ns
-}

godeltaprof/internal/pprof/delta_mutex.go

@@ -14,7 +14,7 @@ type DeltaMutexProfiler struct {
 // are done because The proto expects count and time (nanoseconds) instead of count
 // and the number of cycles for block, contention profiles.
 // Possible 'scaler' functions are scaleBlockProfile and scaleMutexProfile.
-func (d *DeltaMutexProfiler) PrintCountCycleProfile(w io.Writer, countName, cycleName string, scaler func(int64, float64) (int64, float64), records []runtime.BlockProfileRecord) error {
+func (d *DeltaMutexProfiler) PrintCountCycleProfile(w io.Writer, countName, cycleName string, scaler MutexProfileScaler, records []runtime.BlockProfileRecord) error {
 	// Output profile in protobuf form.
 	b := newProfileBuilder(w)
 	b.pbValueType(tagProfile_PeriodType, countName, "count")
@@ -27,7 +27,7 @@ func (d *DeltaMutexProfiler) PrintCountCycleProfile(w io.Writer, countName, cycl
 	values := []int64{0, 0}
 	var locs []uint64
 	for _, r := range records {
-		count, nanosec := scaler(r.Count, float64(r.Cycles)/cpuGHz)
+		count, nanosec := scaleMutexProfile(scaler, r.Count, float64(r.Cycles)/cpuGHz)
 		inanosec := int64(nanosec)
 
 		// do the delta

godeltaprof/internal/pprof/mutex_scale_go19.go

@@ -0,0 +1,27 @@
+//go:build go1.16 && !go1.20
+// +build go1.16,!go1.20
+
+package pprof
+
+import "runtime"
+
+type MutexProfileScaler struct {
+	f func(cnt int64, ns float64) (cnt int64, ns float64)
+}
+
+func scaleMutexProfile(scaler MutexProfileScaler, cnt int64, ns float64) (int64, float64) {
+	return scaler.f(cnt, ns)
+}
+
+var ScalerMutexProfile = MutexProfileScaler{func(cnt int64, ns float64) (int64, float64) {
+	period := runtime.SetMutexProfileFraction(-1)
+	return cnt * int64(period), ns * float64(period)
+}}
+
+var ScalerBlockProfile = MutexProfileScaler{func(cnt int64, ns float64) (int64, float64) {
+	// Do nothing.
+	// The current way of block profile sampling makes it
+	// hard to compute the unsampled number. The legacy block
+	// profile parse doesn't attempt to scale or unsample.
+	return cnt, ns
+}}

godeltaprof/internal/pprof/mutex_scale_go20.go

@@ -0,0 +1,15 @@
+//go:build go1.20
+// +build go1.20
+
+package pprof
+
+type MutexProfileScaler struct {
+}
+
+func scaleMutexProfile(_ MutexProfileScaler, cnt int64, ns float64) (int64, float64) {
+	return cnt, ns
+}
+
+var ScalerMutexProfile = MutexProfileScaler{}
+
+var ScalerBlockProfile = MutexProfileScaler{}