Revert "Set temporary single CPU affinity..."

There's too much logic here figuring out which CPUs to use. Runc is a
low level tool and is not supposed to be that "smart". What's worse,
this logic is executed on every exec, making it slower. Some of the
logic in (*setnsProcess).start is executed even if no annotation is set,
thus making ALL execs slow.

Also, this should be a property of a process, rather than annotation.

The plan is to rework this.

This reverts commit afc23e3.

Signed-off-by: Kir Kolyshkin <[email protected]>

features.go

@@ -68,7 +68,6 @@ var featuresCommand = cli.Command{
  "bundle",
  "org.systemd.property.", // prefix form
  "org.criu.config",
- "org.opencontainers.runc.exec.isolated-cpu-affinity-transition",
  },
  }
 

libcontainer/cgroups/cgroups.go

@@ -72,8 +72,4 @@ type Manager interface {
 
  // OOMKillCount reports OOM kill count for the cgroup.
  OOMKillCount() (uint64, error)
-
- // GetEffectiveCPUs returns the effective CPUs of the cgroup, an empty
- // value means that the cgroups cpuset subsystem/controller is not enabled.
- GetEffectiveCPUs() string
 }

libcontainer/cgroups/fs/fs.go

@@ -4,8 +4,6 @@ import (
  "errors"
  "fmt"
  "os"
- "path/filepath"
- "strings"
  "sync"
 
  "golang.org/x/sys/unix"
@@ -265,28 +263,3 @@ func (m *Manager) OOMKillCount() (uint64, error) {
 
  return c, err
 }
-
-func (m *Manager) GetEffectiveCPUs() string {
- return GetEffectiveCPUs(m.Path("cpuset"), m.cgroups)
-}
-
-func GetEffectiveCPUs(cpusetPath string, cgroups *configs.Cgroup) string {
- // Fast path.
- if cgroups.CpusetCpus != "" {
- return cgroups.CpusetCpus
- } else if !strings.HasPrefix(cpusetPath, defaultCgroupRoot) {
- return ""
- }
-
- // Iterates until it goes to the cgroup root path.
- // It's required for containers in which cpuset controller
- // is not enabled, in this case a parent cgroup is used.
- for path := cpusetPath; path != defaultCgroupRoot; path = filepath.Dir(path) {
- cpus, err := fscommon.GetCgroupParamString(path, "cpuset.effective_cpus")
- if err == nil {
- return cpus
- }
- }
-
- return ""
-}

libcontainer/cgroups/fs2/fs2.go

@@ -4,13 +4,11 @@ import (
  "errors"
  "fmt"
  "os"
- "path/filepath"
  "strings"
 
  "github.com/opencontainers/runc/libcontainer/cgroups"
  "github.com/opencontainers/runc/libcontainer/cgroups/fscommon"
  "github.com/opencontainers/runc/libcontainer/configs"
- "github.com/opencontainers/runc/libcontainer/utils"
 )
 
 type parseError = fscommon.ParseError
@@ -34,9 +32,6 @@ func NewManager(config *configs.Cgroup, dirPath string) (*Manager, error) {
  if err != nil {
  return nil, err
  }
- } else {
- // Clean path for safety.
- dirPath = utils.CleanPath(dirPath)
  }
 
  m := &Manager{
@@ -321,26 +316,3 @@ func CheckMemoryUsage(dirPath string, r *configs.Resources) error {
 
  return nil
 }
-
-func (m *Manager) GetEffectiveCPUs() string {
- // Fast path.
- if m.config.CpusetCpus != "" {
- return m.config.CpusetCpus
- } else if !strings.HasPrefix(m.dirPath, UnifiedMountpoint) {
- return ""
- }
-
- // Iterates until it goes outside of the cgroup root path.
- // It's required for containers in which cpuset controller
- // is not enabled, in this case a parent cgroup is used.
- outsidePath := filepath.Dir(UnifiedMountpoint)
-
- for path := m.dirPath; path != outsidePath; path = filepath.Dir(path) {
- cpus, err := fscommon.GetCgroupParamString(path, "cpuset.cpus.effective")
- if err == nil {
- return cpus
- }
- }
-
- return ""
-}

libcontainer/cgroups/systemd/v1.go

@@ -411,7 +411,3 @@ func (m *LegacyManager) Exists() bool {
 func (m *LegacyManager) OOMKillCount() (uint64, error) {
  return fs.OOMKillCount(m.Path("memory"))
 }
-
-func (m *LegacyManager) GetEffectiveCPUs() string {
- return fs.GetEffectiveCPUs(m.Path("cpuset"), m.cgroups)
-}

libcontainer/cgroups/systemd/v2.go

@@ -514,7 +514,3 @@ func (m *UnifiedManager) Exists() bool {
 func (m *UnifiedManager) OOMKillCount() (uint64, error) {
  return m.fsMgr.OOMKillCount()
 }
-
-func (m *UnifiedManager) GetEffectiveCPUs() string {
- return m.fsMgr.GetEffectiveCPUs()
-}

libcontainer/cgroups/utils.go

@@ -136,18 +136,18 @@ func GetAllSubsystems() ([]string, error) {
  return subsystems, nil
 }
 
-func readProcsFile(dir string) ([]int, error) {
- f, err := OpenFile(dir, CgroupProcesses, os.O_RDONLY)
+func readProcsFile(dir string) (out []int, _ error) {
+ file := CgroupProcesses
+ retry := true
+
+again:
+ f, err := OpenFile(dir, file, os.O_RDONLY)
  if err != nil {
  return nil, err
  }
  defer f.Close()
 
- var (
- s = bufio.NewScanner(f)
- out = []int{}
- )
-
+ s := bufio.NewScanner(f)
  for s.Scan() {
  if t := s.Text(); t != "" {
  pid, err := strconv.Atoi(t)
@@ -157,6 +157,13 @@ func readProcsFile(dir string) ([]int, error) {
  out = append(out, pid)
  }
  }
+ if errors.Is(s.Err(), unix.ENOTSUP) && retry {
+ // For a threaded cgroup, read returns ENOTSUP, and we should
+ // read from cgroup.threads instead.
+ file = "cgroup.threads"
+ retry = false
+ goto again
+ }
  return out, s.Err()
 }
 

libcontainer/container_linux_test.go

@@ -69,10 +69,6 @@ func (m *mockCgroupManager) GetFreezerState() (configs.FreezerState, error) {
  return configs.Thawed, nil
 }
 
-func (m *mockCgroupManager) GetEffectiveCPUs() string {
- return ""
-}
-
 type mockProcess struct {
  _pid int
  started uint64