cmd/prometheus: Undo GOGC adjustment

cmd/prometheus/main.go

@@ -20,7 +20,6 @@ import (
 	_ "net/http/pprof" // Comment this line to disable pprof endpoint.
 	"os"
 	"os/signal"
-	"runtime/debug"
 	"syscall"
 	"time"
 
@@ -42,13 +41,6 @@ func main() {
 	os.Exit(Main())
 }
 
-// defaultGCPercent is the value used to to call SetGCPercent if the GOGC
-// environment variable is not set or empty. The value here is intended to hit
-// the sweet spot between memory utilization and GC effort. It is lower than the
-// usual default of 100 as a lot of the heap in Prometheus is used to cache
-// memory chunks, which have a lifetime of hours if not days or weeks.
-const defaultGCPercent = 40
-
 var (
 	configSuccess = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace: "prometheus",
@@ -78,10 +70,6 @@ func Main() int {
 		return 0
 	}
 
-	if os.Getenv("GOGC") == "" {
-		debug.SetGCPercent(defaultGCPercent)
-	}
-
 	log.Infoln("Starting prometheus", version.Info())
 	log.Infoln("Build context", version.BuildContext())