add TTL for label cache

flags/flags.go

@@ -259,6 +259,7 @@ type FlagsOTLP struct {
 // FlagsProfiling provides profiling configuration flags.
 type FlagsProfiling struct {
 	Duration             time.Duration `default:"5s"                                help:"The agent profiling duration to use. Leave this empty to use the defaults."`
+	LabelTTL             time.Duration `default:"10m"                               help:"The interval at which the agent will refresh the labels of a tid."`
 	CPUSamplingFrequency int           `default:"${default_cpu_sampling_frequency}" help:"The frequency at which profiling data is collected, e.g., 19 samples per second."`
 
 	PerfEventBufferPollInterval       time.Duration `default:"250ms" help:"[deprecated] The interval at which the perf event buffer is polled for new events."`

main.go

@@ -329,6 +329,7 @@ func mainWithExitCode() flags.ExitCode {
 		debuginfoClient,
 		externalLabels,
 		f.Profiling.Duration,
+		f.Profiling.LabelTTL,
 		f.Debuginfo.Strip,
 		f.Debuginfo.UploadMaxParallel,
 		f.Debuginfo.UploadDisable || isOfflineMode,

reporter/parca_reporter.go

@@ -518,6 +518,7 @@ func New(
 	debuginfoClient debuginfogrpc.DebuginfoServiceClient,
 	externalLabels []Label,
 	reportInterval time.Duration,
+	labelTTL time.Duration,
 	stripTextSection bool,
 	symbolUploadConcurrency int,
 	disableSymbolUpload bool,
@@ -543,6 +544,7 @@ func New(
 	if err != nil {
 		return nil, err
 	}
+	labels.SetLifetime(labelTTL)
 
 	stacks, err := lru.NewSynced[libpf.TraceHash, stack](cacheSize, libpf.TraceHash.Hash32)
 	if err != nil {