OffCPU flag (#3037)

* OffCPU flags

* Update go.mod

Author: gnurizen

flags/flags.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/alecthomas/kong"
 	log "github.com/sirupsen/logrus"
+	"go.opentelemetry.io/ebpf-profiler/support"
 	"go.opentelemetry.io/ebpf-profiler/tracer"
 	_ "google.golang.org/grpc/encoding/proto"
 )
@@ -122,7 +123,8 @@ type Flags struct {
 
 	BPF FlagsBPF `embed:"" prefix:"bpf-"`
 
-	OfflineMode FlagsOfflineMode `embed:"" prefix:"offline-mode-"`
+	OfflineMode     FlagsOfflineMode `embed:"" prefix:"offline-mode-"`
+	OffCPUThreshold uint             `default:"0" help:"The per-mille probablity of off-CPU event being recorded."`
 }
 
 type ExitCode int
@@ -202,6 +204,11 @@ func (f Flags) Validate() ExitCode {
 		return ParseError("Specified --offline-mode-upload without --offline-mode-storage-path.")
 	}
 
+	if f.OffCPUThreshold > support.OffCPUThresholdMax {
+		return ParseError("Off-CPU threshold %d exceeds limit (max: %d)",
+			f.OffCPUThreshold, support.OffCPUThresholdMax)
+	}
+
 	return ExitSuccess
 }
 
@@ -355,7 +362,7 @@ type FlagsBPF struct {
 }
 
 type FlagsOfflineMode struct {
-	StoragePath       string        `help:"Enables offline mode, with the data stored at the given path."`
-	RotationInterval  time.Duration `default:"10m" help:"How often to rotate and compress the offline mode log."`
-	Upload            bool          `help:"Run the uploader for data written in offline mode."`
+	StoragePath      string        `help:"Enables offline mode, with the data stored at the given path."`
+	RotationInterval time.Duration `default:"10m" help:"How often to rotate and compress the offline mode log."`
+	Upload           bool          `help:"Run the uploader for data written in offline mode."`
 }

go.mod

@@ -153,4 +153,4 @@ require (
 	sigs.k8s.io/yaml v1.3.0 // indirect
 )
 
-replace go.opentelemetry.io/ebpf-profiler => github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250306230038-78e858b85337
+replace go.opentelemetry.io/ebpf-profiler => github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250311092013-ec1cdb3482af

go.sum

@@ -258,8 +258,8 @@ github.com/opencontainers/runtime-spec v1.1.0 h1:HHUyrt9mwHUjtasSbXSMvs4cyFxh+Bl
 github.com/opencontainers/runtime-spec v1.1.0/go.mod h1:jwyrGlmzljRJv/Fgzds9SsS/C5hL+LL3ko9hs6T5lQ0=
 github.com/opencontainers/selinux v1.11.0 h1:+5Zbo97w3Lbmb3PeqQtpmTkMwsW5nRI3YaLpt7tQ7oU=
 github.com/opencontainers/selinux v1.11.0/go.mod h1:E5dMC3VPuVvVHDYmi78qvhJp8+M586T4DlDRYpFkyec=
-github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250306230038-78e858b85337 h1:qJ3p+TmnDFPAX+XhBSHpgnETRofp8Yn6FzOBfwxKzyc=
-github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250306230038-78e858b85337/go.mod h1:q15sN2PgXSh337bNjdeUz4WCIlqQrO/Nx0H5O7o5WiI=
+github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250311092013-ec1cdb3482af h1:2MhE8xUeyjPux1INz/40WEt7raxzUNMiRfGSNIb7gc0=
+github.com/parca-dev/opentelemetry-ebpf-profiler v0.0.0-20250311092013-ec1cdb3482af/go.mod h1:q15sN2PgXSh337bNjdeUz4WCIlqQrO/Nx0H5O7o5WiI=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 h1:onHthvaw9LFnH4t2DcNVpwGmV9E1BkGknEliJkfwQj0=
 github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58/go.mod h1:DXv8WO4yhMYhSNPKjeNKa5WY9YCIEBRbNzFFPJbWO6Y=
 github.com/pierrec/lz4/v4 v4.1.21 h1:yOVMLb6qSIDP67pl/5F7RepeKYu/VmTyEXvuMI5d9mQ=

main.go

@@ -361,6 +361,7 @@ func mainWithExitCode() flags.ExitCode {
 		ProbabilisticInterval:  f.Profiling.ProbabilisticInterval,
 		ProbabilisticThreshold: f.Profiling.ProbabilisticThreshold,
 		CollectCustomLabels:    f.CollectCustomLabels,
+		OffCPUThreshold:        uint32(f.OffCPUThreshold),
 	})
 	if err != nil {
 		return flags.Failure("Failed to load eBPF tracer: %v", err)