1// +build linux 2 3package fs 4 5import ( 6 "bufio" 7 "os" 8 "path/filepath" 9 "strconv" 10 11 "github.com/opencontainers/runc/libcontainer/cgroups" 12 "github.com/opencontainers/runc/libcontainer/configs" 13) 14 15type CpuGroup struct { 16} 17 18func (s *CpuGroup) Name() string { 19 return "cpu" 20} 21 22func (s *CpuGroup) Apply(d *cgroupData) error { 23 // We always want to join the cpu group, to allow fair cpu scheduling 24 // on a container basis 25 path, err := d.path("cpu") 26 if err != nil && !cgroups.IsNotFound(err) { 27 return err 28 } 29 return s.ApplyDir(path, d.config, d.pid) 30} 31 32func (s *CpuGroup) ApplyDir(path string, cgroup *configs.Cgroup, pid int) error { 33 // This might happen if we have no cpu cgroup mounted. 34 // Just do nothing and don't fail. 35 if path == "" { 36 return nil 37 } 38 if err := os.MkdirAll(path, 0755); err != nil { 39 return err 40 } 41 // We should set the real-Time group scheduling settings before moving 42 // in the process because if the process is already in SCHED_RR mode 43 // and no RT bandwidth is set, adding it will fail. 44 if err := s.SetRtSched(path, cgroup); err != nil { 45 return err 46 } 47 // because we are not using d.join we need to place the pid into the procs file 48 // unlike the other subsystems 49 return cgroups.WriteCgroupProc(path, pid) 50} 51 52func (s *CpuGroup) SetRtSched(path string, cgroup *configs.Cgroup) error { 53 if cgroup.Resources.CpuRtPeriod != 0 { 54 if err := writeFile(path, "cpu.rt_period_us", strconv.FormatUint(cgroup.Resources.CpuRtPeriod, 10)); err != nil { 55 return err 56 } 57 } 58 if cgroup.Resources.CpuRtRuntime != 0 { 59 if err := writeFile(path, "cpu.rt_runtime_us", strconv.FormatInt(cgroup.Resources.CpuRtRuntime, 10)); err != nil { 60 return err 61 } 62 } 63 return nil 64} 65 66func (s *CpuGroup) Set(path string, cgroup *configs.Cgroup) error { 67 if cgroup.Resources.CpuShares != 0 { 68 if err := writeFile(path, "cpu.shares", strconv.FormatUint(cgroup.Resources.CpuShares, 10)); err != nil { 69 return err 70 } 71 } 72 if cgroup.Resources.CpuPeriod != 0 { 73 if err := writeFile(path, "cpu.cfs_period_us", strconv.FormatUint(cgroup.Resources.CpuPeriod, 10)); err != nil { 74 return err 75 } 76 } 77 if cgroup.Resources.CpuQuota != 0 { 78 if err := writeFile(path, "cpu.cfs_quota_us", strconv.FormatInt(cgroup.Resources.CpuQuota, 10)); err != nil { 79 return err 80 } 81 } 82 return s.SetRtSched(path, cgroup) 83} 84 85func (s *CpuGroup) Remove(d *cgroupData) error { 86 return removePath(d.path("cpu")) 87} 88 89func (s *CpuGroup) GetStats(path string, stats *cgroups.Stats) error { 90 f, err := os.Open(filepath.Join(path, "cpu.stat")) 91 if err != nil { 92 if os.IsNotExist(err) { 93 return nil 94 } 95 return err 96 } 97 defer f.Close() 98 99 sc := bufio.NewScanner(f) 100 for sc.Scan() { 101 t, v, err := getCgroupParamKeyValue(sc.Text()) 102 if err != nil { 103 return err 104 } 105 switch t { 106 case "nr_periods": 107 stats.CpuStats.ThrottlingData.Periods = v 108 109 case "nr_throttled": 110 stats.CpuStats.ThrottlingData.ThrottledPeriods = v 111 112 case "throttled_time": 113 stats.CpuStats.ThrottlingData.ThrottledTime = v 114 } 115 } 116 return nil 117} 118