lib/cgroup: remove SetGOGC() function

GOGC can be already set via environment variable. There is no need in adding
new approaches for setting the GOGC (such as command-line flag), since they complicate operations.

app/victoria-logs/main.go

@@ -11,7 +11,6 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vlselect"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vlstorage"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/buildinfo"
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/cgroup"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/envflag"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/flagutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
@@ -26,7 +25,6 @@ var (
 	useProxyProtocol = flag.Bool("httpListenAddr.useProxyProtocol", false, "Whether to use proxy protocol for connections accepted at -httpListenAddr . "+
 		"See https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt . "+
 		"With enabled proxy protocol http server cannot serve regular /metrics endpoint. Use -pushmetrics.url for metrics pushing")
-	gogc = flag.Int("gogc", 100, "GOGC to use. See https://tip.golang.org/doc/gc-guide")
 )
 
 func main() {
@@ -34,7 +32,6 @@ func main() {
 	flag.CommandLine.SetOutput(os.Stdout)
 	flag.Usage = usage
 	envflag.Parse()
-	cgroup.SetGOGC(*gogc)
 	buildinfo.Init()
 	logger.Init()
 

lib/cgroup/mem.go

@@ -34,18 +34,6 @@ func initGOGC() {
 	}
 }
 
-// SetGOGC sets GOGC to the given percent
-func SetGOGC(percent int) {
-	if percent <= 0 {
-		return
-	}
-	if percent > 100 {
-		percent = 100
-	}
-	gogc = percent
-	debug.SetGCPercent(gogc)
-}
-
 var gogc int
 
 // GetMemoryLimit returns cgroup memory limit