[1.1] libct: rm intelrtd.Manager interface, NewIntelRdtManager

[This is a manual port of commit dbd990d to release-1.1
branch. Original description follows.]

Remove intelrtd.Manager interface, since we only have a single
implementation, and do not expect another one.

Rename intelRdtManager to Manager, and modify its users accordingly.

Remove NewIntelRdtManager from factory.

Remove IntelRdtfs. Instead, make intelrdt.NewManager return nil if the
feature is not available.

Remove TestFactoryNewIntelRdt as it is now identical to TestFactoryNew.

Add internal function newManager to be used for tests (to make sure
some testing is done even when the feature is not available in
kernel/hardware).

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

Author: kolyshkin

libcontainer/container_linux.go

@@ -40,7 +40,7 @@ type linuxContainer struct {
 	root                 string
 	config               *configs.Config
 	cgroupManager        cgroups.Manager
-	intelRdtManager      intelrdt.Manager
+	intelRdtManager      *intelrdt.Manager
 	initPath             string
 	initArgs             []string
 	initProcess          parentProcess

libcontainer/factory_linux.go

@@ -48,20 +48,6 @@ func InitArgs(args ...string) func(*LinuxFactory) error {
 	}
 }
 
-// IntelRdtfs is an options func to configure a LinuxFactory to return
-// containers that use the Intel RDT "resource control" filesystem to
-// create and manage Intel RDT resources (e.g., L3 cache, memory bandwidth).
-func IntelRdtFs(l *LinuxFactory) error {
-	if !intelrdt.IsCATEnabled() && !intelrdt.IsMBAEnabled() {
-		l.NewIntelRdtManager = nil
-	} else {
-		l.NewIntelRdtManager = func(config *configs.Config, id string, path string) intelrdt.Manager {
-			return intelrdt.NewManager(config, id, path)
-		}
-	}
-	return nil
-}
-
 // TmpfsRoot is an option func to mount LinuxFactory.Root to tmpfs.
 func TmpfsRoot(l *LinuxFactory) error {
 	mounted, err := mountinfo.Mounted(l.Root)
@@ -136,9 +122,6 @@ type LinuxFactory struct {
 
 	// Validator provides validation to container configurations.
 	Validator validate.Validator
-
-	// NewIntelRdtManager returns an initialized Intel RDT manager for a single container.
-	NewIntelRdtManager func(config *configs.Config, id string, path string) intelrdt.Manager
 }
 
 func (l *LinuxFactory) Create(id string, config *configs.Config) (Container, error) {
@@ -208,18 +191,16 @@ func (l *LinuxFactory) Create(id string, config *configs.Config) (Container, err
 		return nil, err
 	}
 	c := &linuxContainer{
-		id:            id,
-		root:          containerRoot,
-		config:        config,
-		initPath:      l.InitPath,
-		initArgs:      l.InitArgs,
-		criuPath:      l.CriuPath,
-		newuidmapPath: l.NewuidmapPath,
-		newgidmapPath: l.NewgidmapPath,
-		cgroupManager: cm,
-	}
-	if l.NewIntelRdtManager != nil {
-		c.intelRdtManager = l.NewIntelRdtManager(config, id, "")
+		id:              id,
+		root:            containerRoot,
+		config:          config,
+		initPath:        l.InitPath,
+		initArgs:        l.InitArgs,
+		criuPath:        l.CriuPath,
+		newuidmapPath:   l.NewuidmapPath,
+		newgidmapPath:   l.NewgidmapPath,
+		cgroupManager:   cm,
+		intelRdtManager: intelrdt.NewManager(config, id, ""),
 	}
 	c.state = &stoppedState{c: c}
 	return c, nil
@@ -261,12 +242,10 @@ func (l *LinuxFactory) Load(id string) (Container, error) {
 		newuidmapPath:        l.NewuidmapPath,
 		newgidmapPath:        l.NewgidmapPath,
 		cgroupManager:        cm,
+		intelRdtManager:      intelrdt.NewManager(&state.Config, id, state.IntelRdtPath),
 		root:                 containerRoot,
 		created:              state.Created,
 	}
-	if l.NewIntelRdtManager != nil {
-		c.intelRdtManager = l.NewIntelRdtManager(&state.Config, id, state.IntelRdtPath)
-	}
 	c.state = &loadedState{c: c}
 	if err := c.refreshState(); err != nil {
 		return nil, err

libcontainer/factory_linux_test.go

@@ -37,28 +37,6 @@ func TestFactoryNew(t *testing.T) {
 	}
 }
 
-func TestFactoryNewIntelRdt(t *testing.T) {
-	root := t.TempDir()
-	factory, err := New(root, IntelRdtFs)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if factory == nil {
-		t.Fatal("factory should not be nil")
-	}
-	lfactory, ok := factory.(*LinuxFactory)
-	if !ok {
-		t.Fatal("expected linux factory returned on linux based systems")
-	}
-	if lfactory.Root != root {
-		t.Fatalf("expected factory root to be %q but received %q", root, lfactory.Root)
-	}
-
-	if factory.Type() != "libcontainer" {
-		t.Fatalf("unexpected factory type: %q, expected %q", factory.Type(), "libcontainer")
-	}
-}
-
 func TestFactoryNewTmpfs(t *testing.T) {
 	root := t.TempDir()
 	factory, err := New(root, TmpfsRoot)
@@ -157,7 +135,7 @@ func TestFactoryLoadContainer(t *testing.T) {
 	if err := marshal(filepath.Join(root, id, stateFilename), expectedState); err != nil {
 		t.Fatal(err)
 	}
-	factory, err := New(root, IntelRdtFs)
+	factory, err := New(root)
 	if err != nil {
 		t.Fatal(err)
 	}

libcontainer/intelrdt/intelrdt.go

@@ -146,34 +146,27 @@ import (
  * }
  */
 
-type Manager interface {
-	// Applies Intel RDT configuration to the process with the specified pid
-	Apply(pid int) error
-
-	// Returns statistics for Intel RDT
-	GetStats() (*Stats, error)
-
-	// Destroys the Intel RDT container-specific 'container_id' group
-	Destroy() error
-
-	// Returns Intel RDT path to save in a state file and to be able to
-	// restore the object later
-	GetPath() string
-
-	// Set Intel RDT "resource control" filesystem as configured.
-	Set(container *configs.Config) error
-}
-
-// This implements interface Manager
-type intelRdtManager struct {
+// NewManager returns a new instance of Manager, or nil, if the Intel RDT
+// functionality is not available from hardware or not enabled in the kernel.
+type Manager struct {
 	mu     sync.Mutex
 	config *configs.Config
 	id     string
 	path   string
 }
 
-func NewManager(config *configs.Config, id string, path string) Manager {
-	return &intelRdtManager{
+func NewManager(config *configs.Config, id string, path string) *Manager {
+	if _, err := Root(); err != nil {
+		// Intel RDT is not available.
+		return nil
+	}
+	return newManager(config, id, path)
+}
+
+// newManager is the same as NewManager, except it does not check if the feature
+// is actually available. Used by unit tests that mock intelrdt paths.
+func newManager(config *configs.Config, id string, path string) *Manager {
+	return &Manager{
 		config: config,
 		id:     id,
 		path:   path,
@@ -507,7 +500,7 @@ func IsMBAScEnabled() bool {
 }
 
 // Get the path of the clos group in "resource control" filesystem that the container belongs to
-func (m *intelRdtManager) getIntelRdtPath() (string, error) {
+func (m *Manager) getIntelRdtPath() (string, error) {
 	rootPath, err := Root()
 	if err != nil {
 		return "", err
@@ -522,7 +515,7 @@ func (m *intelRdtManager) getIntelRdtPath() (string, error) {
 }
 
 // Applies Intel RDT configuration to the process with the specified pid
-func (m *intelRdtManager) Apply(pid int) (err error) {
+func (m *Manager) Apply(pid int) (err error) {
 	// If intelRdt is not specified in config, we do nothing
 	if m.config.IntelRdt == nil {
 		return nil
@@ -557,7 +550,7 @@ func (m *intelRdtManager) Apply(pid int) (err error) {
 }
 
 // Destroys the Intel RDT container-specific 'container_id' group
-func (m *intelRdtManager) Destroy() error {
+func (m *Manager) Destroy() error {
 	// Don't remove resctrl group if closid has been explicitly specified. The
 	// group is likely externally managed, i.e. by some other entity than us.
 	// There are probably other containers/tasks sharing the same group.
@@ -574,15 +567,15 @@ func (m *intelRdtManager) Destroy() error {
 
 // Returns Intel RDT path to save in a state file and to be able to
 // restore the object later
-func (m *intelRdtManager) GetPath() string {
+func (m *Manager) GetPath() string {
 	if m.path == "" {
 		m.path, _ = m.getIntelRdtPath()
 	}
 	return m.path
 }
 
 // Returns statistics for Intel RDT
-func (m *intelRdtManager) GetStats() (*Stats, error) {
+func (m *Manager) GetStats() (*Stats, error) {
 	// If intelRdt is not specified in config
 	if m.config.IntelRdt == nil {
 		return nil, nil
@@ -668,7 +661,7 @@ func (m *intelRdtManager) GetStats() (*Stats, error) {
 }
 
 // Set Intel RDT "resource control" filesystem as configured.
-func (m *intelRdtManager) Set(container *configs.Config) error {
+func (m *Manager) Set(container *configs.Config) error {
 	// About L3 cache schema:
 	// It has allocation bitmasks/values for L3 cache on each socket,
 	// which contains L3 cache id and capacity bitmask (CBM).

libcontainer/intelrdt/intelrdt_test.go

@@ -20,7 +20,7 @@ func TestIntelRdtSetL3CacheSchema(t *testing.T) {
 	})
 
 	helper.config.IntelRdt.L3CacheSchema = l3CacheSchemeAfter
-	intelrdt := NewManager(helper.config, "", helper.IntelRdtPath)
+	intelrdt := newManager(helper.config, "", helper.IntelRdtPath)
 	if err := intelrdt.Set(helper.config); err != nil {
 		t.Fatal(err)
 	}
@@ -50,7 +50,7 @@ func TestIntelRdtSetMemBwSchema(t *testing.T) {
 	})
 
 	helper.config.IntelRdt.MemBwSchema = memBwSchemeAfter
-	intelrdt := NewManager(helper.config, "", helper.IntelRdtPath)
+	intelrdt := newManager(helper.config, "", helper.IntelRdtPath)
 	if err := intelrdt.Set(helper.config); err != nil {
 		t.Fatal(err)
 	}
@@ -80,7 +80,7 @@ func TestIntelRdtSetMemBwScSchema(t *testing.T) {
 	})
 
 	helper.config.IntelRdt.MemBwSchema = memBwScSchemeAfter
-	intelrdt := NewManager(helper.config, "", helper.IntelRdtPath)
+	intelrdt := newManager(helper.config, "", helper.IntelRdtPath)
 	if err := intelrdt.Set(helper.config); err != nil {
 		t.Fatal(err)
 	}
@@ -103,7 +103,7 @@ func TestApply(t *testing.T) {
 	const closID = "test-clos"
 
 	helper.config.IntelRdt.ClosID = closID
-	intelrdt := NewManager(helper.config, "", helper.IntelRdtPath)
+	intelrdt := newManager(helper.config, "", helper.IntelRdtPath)
 	if err := intelrdt.Apply(1234); err == nil {
 		t.Fatal("unexpected success when applying pid")
 	}
@@ -112,7 +112,7 @@ func TestApply(t *testing.T) {
 	}
 
 	// Dir should be created if some schema has been specified
-	intelrdt.(*intelRdtManager).config.IntelRdt.L3CacheSchema = "L3:0=f"
+	intelrdt.config.IntelRdt.L3CacheSchema = "L3:0=f"
 	if err := intelrdt.Apply(1235); err != nil {
 		t.Fatalf("Apply() failed: %v", err)
 	}

libcontainer/process_linux.go

@@ -299,7 +299,7 @@ type initProcess struct {
 	logFilePair     filePair
 	config          *initConfig
 	manager         cgroups.Manager
-	intelRdtManager intelrdt.Manager
+	intelRdtManager *intelrdt.Manager
 	container       *linuxContainer
 	fds             []string
 	process         *Process

utils_linux.go

@@ -32,8 +32,6 @@ func loadFactory(context *cli.Context) (libcontainer.Factory, error) {
 		return nil, err
 	}
 
-	intelRdtManager := libcontainer.IntelRdtFs
-
 	// We resolve the paths for {newuidmap,newgidmap} from the context of runc,
 	// to avoid doing a path lookup in the nsexec context. TODO: The binary
 	// names are not currently configurable.
@@ -46,7 +44,7 @@ func loadFactory(context *cli.Context) (libcontainer.Factory, error) {
 		newgidmap = ""
 	}
 
-	return libcontainer.New(abs, intelRdtManager,
+	return libcontainer.New(abs,
 		libcontainer.CriuPath(context.GlobalString("criu")),
 		libcontainer.NewuidmapPath(newuidmap),
 		libcontainer.NewgidmapPath(newgidmap))