package cgroup import ( "os" "runtime" "github.com/VictoriaMetrics/VictoriaMetrics/lib/logger" ) // UpdateGOMAXPROCSToCPUQuota updates GOMAXPROCS to cgroup CPU quota if GOMAXPROCS isn't set in environment var. // // This function must be called after logger.Init(). func UpdateGOMAXPROCSToCPUQuota() { if v := os.Getenv("GOMAXPROCS"); v != "" { return } q := getCPUQuota() if q <= 0 { // Do not change GOMAXPROCS return } gomaxprocs := int(q + 0.5) if gomaxprocs <= 0 { gomaxprocs = 1 } logger.Infof("updating GOMAXPROCS to %d according to cgroup CPU quota", gomaxprocs) runtime.GOMAXPROCS(gomaxprocs) } func getCPUQuota() float64 { quotaUS, err := readInt64("/sys/fs/cgroup/cpu/cpu.cfs_quota_us", "cat /sys/fs/cgroup/cpu$(cat /proc/self/cgroup | grep cpu, | cut -d: -f3)/cpu.cfs_quota_us") if err != nil { return 0 } periodUS, err := readInt64("/sys/fs/cgroup/cpu/cpu.cfs_period_us", "cat /sys/fs/cgroup/cpu$(cat /proc/self/cgroup | grep cpu, | cut -d: -f3)/cpu.cfs_period_us") if err != nil { return 0 } return float64(quotaUS) / float64(periodUS) }