resources: make maxsamples configurable

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

executor/resources/monitor.go

@@ -51,7 +51,7 @@ func (r *cgroupRecord) Start() {
 	if stat, err := r.monitor.proc.Stat(); err == nil {
 		r.startCPUStat = &stat.CPUTotal
 	}
-	s := NewSampler(2*time.Second, r.sample)
+	s := NewSampler(2*time.Second, 10, r.sample)
 	r.sampler = s.Record()
 	r.closeSampler = s.Close
 }

executor/resources/sampler.go

@@ -12,6 +12,7 @@ type WithTimestamp interface {
 type Sampler[T WithTimestamp] struct {
 	mu          sync.RWMutex
 	minInterval time.Duration
+	maxSamples  int
 	callback    func(ts time.Time) (T, error)
 	doneOnce    sync.Once
 	done        chan struct{}
@@ -57,9 +58,10 @@ func (s *Sub[T]) Close(captureLast bool) ([]T, error) {
 	return out, nil
 }
 
-func NewSampler[T WithTimestamp](minInterval time.Duration, cb func(time.Time) (T, error)) *Sampler[T] {
+func NewSampler[T WithTimestamp](minInterval time.Duration, maxSamples int, cb func(time.Time) (T, error)) *Sampler[T] {
 	s := &Sampler[T]{
 		minInterval: minInterval,
+		maxSamples:  maxSamples,
 		callback:    cb,
 		done:        make(chan struct{}),
 		subs:        make(map[*Sub[T]]struct{}),
@@ -115,7 +117,7 @@ func (s *Sampler[T]) run() {
 					ss.err = nil
 				}
 				dur := ss.last.Sub(ss.first)
-				if time.Duration(ss.interval)*10 <= dur {
+				if time.Duration(ss.interval)*time.Duration(s.maxSamples) <= dur {
 					ss.interval *= 2
 				}
 			}

executor/resources/sys.go

@@ -16,7 +16,7 @@ func NewSysSampler() (*Sampler[*types.SysSample], error) {
 		return nil, err
 	}
 
-	return NewSampler(2*time.Second, func(tm time.Time) (*types.SysSample, error) {
+	return NewSampler(2*time.Second, 20, func(tm time.Time) (*types.SysSample, error) {
 		return sampleSys(procfs, tm)
 	}), nil
 }