diff options
Diffstat (limited to 'vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/cpuset.go')
-rw-r--r-- | vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/cpuset.go | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/cpuset.go b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/cpuset.go new file mode 100644 index 000000000..20c9eafac --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/cgroups/fs/cpuset.go @@ -0,0 +1,163 @@ +// +build linux + +package fs + +import ( + "bytes" + "fmt" + "io/ioutil" + "os" + "path/filepath" + + "github.com/opencontainers/runc/libcontainer/cgroups" + "github.com/opencontainers/runc/libcontainer/configs" + libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils" +) + +type CpusetGroup struct { +} + +func (s *CpusetGroup) Name() string { + return "cpuset" +} + +func (s *CpusetGroup) Apply(d *cgroupData) error { + dir, err := d.path("cpuset") + if err != nil && !cgroups.IsNotFound(err) { + return err + } + return s.ApplyDir(dir, d.config, d.pid) +} + +func (s *CpusetGroup) Set(path string, cgroup *configs.Cgroup) error { + if cgroup.Resources.CpusetCpus != "" { + if err := writeFile(path, "cpuset.cpus", cgroup.Resources.CpusetCpus); err != nil { + return err + } + } + if cgroup.Resources.CpusetMems != "" { + if err := writeFile(path, "cpuset.mems", cgroup.Resources.CpusetMems); err != nil { + return err + } + } + return nil +} + +func (s *CpusetGroup) Remove(d *cgroupData) error { + return removePath(d.path("cpuset")) +} + +func (s *CpusetGroup) GetStats(path string, stats *cgroups.Stats) error { + return nil +} + +func (s *CpusetGroup) ApplyDir(dir string, cgroup *configs.Cgroup, pid int) error { + // This might happen if we have no cpuset cgroup mounted. + // Just do nothing and don't fail. + if dir == "" { + return nil + } + mountInfo, err := ioutil.ReadFile("/proc/self/mountinfo") + if err != nil { + return err + } + root := filepath.Dir(cgroups.GetClosestMountpointAncestor(dir, string(mountInfo))) + // 'ensureParent' start with parent because we don't want to + // explicitly inherit from parent, it could conflict with + // 'cpuset.cpu_exclusive'. + if err := s.ensureParent(filepath.Dir(dir), root); err != nil { + return err + } + if err := os.MkdirAll(dir, 0755); err != nil { + return err + } + // We didn't inherit cpuset configs from parent, but we have + // to ensure cpuset configs are set before moving task into the + // cgroup. + // The logic is, if user specified cpuset configs, use these + // specified configs, otherwise, inherit from parent. This makes + // cpuset configs work correctly with 'cpuset.cpu_exclusive', and + // keep backward compatbility. + if err := s.ensureCpusAndMems(dir, cgroup); err != nil { + return err + } + + // because we are not using d.join we need to place the pid into the procs file + // unlike the other subsystems + if err := cgroups.WriteCgroupProc(dir, pid); err != nil { + return err + } + + return nil +} + +func (s *CpusetGroup) getSubsystemSettings(parent string) (cpus []byte, mems []byte, err error) { + if cpus, err = ioutil.ReadFile(filepath.Join(parent, "cpuset.cpus")); err != nil { + return + } + if mems, err = ioutil.ReadFile(filepath.Join(parent, "cpuset.mems")); err != nil { + return + } + return cpus, mems, nil +} + +// ensureParent makes sure that the parent directory of current is created +// and populated with the proper cpus and mems files copied from +// it's parent. +func (s *CpusetGroup) ensureParent(current, root string) error { + parent := filepath.Dir(current) + if libcontainerUtils.CleanPath(parent) == root { + return nil + } + // Avoid infinite recursion. + if parent == current { + return fmt.Errorf("cpuset: cgroup parent path outside cgroup root") + } + if err := s.ensureParent(parent, root); err != nil { + return err + } + if err := os.MkdirAll(current, 0755); err != nil { + return err + } + return s.copyIfNeeded(current, parent) +} + +// copyIfNeeded copies the cpuset.cpus and cpuset.mems from the parent +// directory to the current directory if the file's contents are 0 +func (s *CpusetGroup) copyIfNeeded(current, parent string) error { + var ( + err error + currentCpus, currentMems []byte + parentCpus, parentMems []byte + ) + + if currentCpus, currentMems, err = s.getSubsystemSettings(current); err != nil { + return err + } + if parentCpus, parentMems, err = s.getSubsystemSettings(parent); err != nil { + return err + } + + if s.isEmpty(currentCpus) { + if err := writeFile(current, "cpuset.cpus", string(parentCpus)); err != nil { + return err + } + } + if s.isEmpty(currentMems) { + if err := writeFile(current, "cpuset.mems", string(parentMems)); err != nil { + return err + } + } + return nil +} + +func (s *CpusetGroup) isEmpty(b []byte) bool { + return len(bytes.Trim(b, "\n")) == 0 +} + +func (s *CpusetGroup) ensureCpusAndMems(path string, cgroup *configs.Cgroup) error { + if err := s.Set(path, cgroup); err != nil { + return err + } + return s.copyIfNeeded(path, filepath.Dir(path)) +} |