cmd/swarm: add pprof custom profiles through flags

cmd/swarm/flags.go

@@ -249,4 +249,12 @@ var (
 		Name:  "verbose",
 		Usage: "Display more verbose output",
 	}
+	SwarmMutexProfileFlag = cli.BoolFlag{
+		Name:  "mutex-profile",
+		Usage: "Enable pprof mutex profile",
+	}
+	SwarmBlockProfileFlag = cli.BoolFlag{
+		Name:  "block-profile",
+		Usage: "Enable pprof block profile",
+	}
 )

cmd/swarm/main.go

@@ -102,6 +102,8 @@ func init() {
 	defaultNodeConfig.IPCPath = "bzzd.ipc"
 	// Set flag defaults for --help display.
 	utils.ListenPortFlag.Value = 30399
+
+	runtime.SetMutexProfileFraction(5)
 }
 
 var app = utils.NewApp("", "", "Ethereum Swarm")
@@ -213,6 +215,9 @@ func init() {
 		SwarmStoreCapacity,
 		SwarmStoreCacheCapacity,
 		SwarmGlobalStoreAPIFlag,
+		// debugging
+		SwarmMutexProfileFlag,
+		SwarmBlockProfileFlag,
 	}
 	rpcFlags := []cli.Flag{
 		utils.WSEnabledFlag,
@@ -295,6 +300,9 @@ func bzzd(ctx *cli.Context) error {
 		cfg.DataDir = bzzconfig.Path
 	}
 
+	// start any custom pprof profiles
+	pprofProfiles(ctx)
+
 	//optionally set the bootnodes before configuring the node
 	setSwarmBootstrapNodes(ctx, &cfg)
 	//setup the ethereum node
@@ -567,3 +575,13 @@ func setSwarmNATFromInterface(ctx *cli.Context, cfg *node.Config) {
 	}
 	cfg.P2P.NAT = nat.ExtIP(ip)
 }
+
+func pprofProfiles(ctx *cli.Context) {
+	if ctx.GlobalBool(SwarmMutexProfileFlag.Name) {
+		runtime.SetMutexProfileFraction(1)
+	}
+
+	if ctx.GlobalBool(SwarmBlockProfileFlag.Name) {
+		runtime.SetBlockProfileRate(1)
+	}
+}