Ensure devicemanager TopologyHints are regenerated after kubelet restart

This patch also includes test to make sure the newly added logic works
as expected.

pkg/kubelet/cm/devicemanager/BUILD

@@ -60,6 +60,7 @@ go_test(
         "//staging/src/k8s.io/api/core/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/api/resource:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/types:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/uuid:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",

pkg/kubelet/cm/devicemanager/topology_hints.go

@@ -46,6 +46,21 @@ func (m *ManagerImpl) GetTopologyHints(pod v1.Pod, container v1.Container) map[s
 				continue
 			}
 
+			// Short circuit to regenerate the same hints if there are already
+			// devices allocated to the Container. This might happen after a
+			// kubelet restart, for example.
+			allocated := m.podDevices.containerDevices(string(pod.UID), container.Name, resource)
+			if allocated.Len() > 0 {
+				if allocated.Len() != requested {
+					klog.Errorf("[devicemanager] Resource '%v' already allocated to (pod %v, container %v) with different number than request: requested: %d, allocated: %d", resource, string(pod.UID), container.Name, requested, allocated.Len())
+					deviceHints[resource] = []topologymanager.TopologyHint{}
+					continue
+				}
+				klog.Infof("[devicemanager] Regenerating TopologyHints for resource '%v' already allocated to (pod %v, container %v)", resource, string(pod.UID), container.Name)
+				deviceHints[resource] = m.generateDeviceTopologyHints(resource, allocated, requested)
+				continue
+			}
+
 			// Get the list of available devices, for which TopologyHints should be generated.
 			available := m.getAvailableDevices(resource)
 			if available.Len() < requested {

pkg/kubelet/cm/devicemanager/topology_hints_test.go

@@ -23,6 +23,7 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/sets"
 	pluginapi "k8s.io/kubelet/pkg/apis/deviceplugin/v1beta1"
 	"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager"
@@ -52,13 +53,17 @@ func makeSocketMask(sockets ...int) bitmask.BitMask {
 func TestGetTopologyHints(t *testing.T) {
 	tcases := []struct {
 		description      string
+		podUID           string
+		containerName    string
 		request          map[string]string
 		devices          map[string][]pluginapi.Device
-		allocatedDevices map[string][]string
+		allocatedDevices map[string]map[string]map[string][]string
 		expectedHints    map[string][]topologymanager.TopologyHint
 	}{
 		{
 			description:   "Single Request, no alignment",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "1",
 			},
@@ -74,6 +79,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "Single Request, only one with alignment",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "1",
 			},
@@ -98,6 +105,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "Single Request, one device per socket",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "1",
 			},
@@ -126,6 +135,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "Request for 2, one device per socket",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "2",
 			},
@@ -146,6 +157,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "Request for 2, 2 devices per socket",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "2",
 			},
@@ -176,6 +189,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "Request for 2, optimal on 1 NUMA node, forced cross-NUMA",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice": "2",
 			},
@@ -187,9 +202,13 @@ func TestGetTopologyHints(t *testing.T) {
 					makeNUMADevice("Dev4", 1),
 				},
 			},
-			allocatedDevices: map[string][]string{
+			allocatedDevices: map[string]map[string]map[string][]string{
+				"fakePod": {
+					"fakeOtherContainer": {
 						"testdevice": {"Dev1", "Dev2"},
 					},
+				},
+			},
 			expectedHints: map[string][]topologymanager.TopologyHint{
 				"testdevice": {
 					{
@@ -201,6 +220,8 @@ func TestGetTopologyHints(t *testing.T) {
 		},
 		{
 			description:   "2 device types, mixed configuration",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
 			request: map[string]string{
 				"testdevice1": "2",
 				"testdevice2": "1",
@@ -243,6 +264,110 @@ func TestGetTopologyHints(t *testing.T) {
 				},
 			},
 		},
+		{
+			description:   "Single device type, more requested than available",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
+			request: map[string]string{
+				"testdevice": "6",
+			},
+			devices: map[string][]pluginapi.Device{
+				"testdevice": {
+					makeNUMADevice("Dev1", 0),
+					makeNUMADevice("Dev2", 0),
+					makeNUMADevice("Dev3", 1),
+					makeNUMADevice("Dev4", 1),
+				},
+			},
+			expectedHints: map[string][]topologymanager.TopologyHint{
+				"testdevice": {},
+			},
+		},
+		{
+			description:   "Single device type, all already allocated to container",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
+			request: map[string]string{
+				"testdevice": "2",
+			},
+			devices: map[string][]pluginapi.Device{
+				"testdevice": {
+					makeNUMADevice("Dev1", 0),
+					makeNUMADevice("Dev2", 0),
+				},
+			},
+			allocatedDevices: map[string]map[string]map[string][]string{
+				"fakePod": {
+					"fakeContainer": {
+						"testdevice": {"Dev1", "Dev2"},
+					},
+				},
+			},
+			expectedHints: map[string][]topologymanager.TopologyHint{
+				"testdevice": {
+					{
+						NUMANodeAffinity: makeSocketMask(0),
+						Preferred:        true,
+					},
+					{
+						NUMANodeAffinity: makeSocketMask(0, 1),
+						Preferred:        false,
+					},
+				},
+			},
+		},
+		{
+			description:   "Single device type, less already allocated to container than requested",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
+			request: map[string]string{
+				"testdevice": "4",
+			},
+			devices: map[string][]pluginapi.Device{
+				"testdevice": {
+					makeNUMADevice("Dev1", 0),
+					makeNUMADevice("Dev2", 0),
+					makeNUMADevice("Dev3", 1),
+					makeNUMADevice("Dev4", 1),
+				},
+			},
+			allocatedDevices: map[string]map[string]map[string][]string{
+				"fakePod": {
+					"fakeContainer": {
+						"testdevice": {"Dev1", "Dev2"},
+					},
+				},
+			},
+			expectedHints: map[string][]topologymanager.TopologyHint{
+				"testdevice": {},
+			},
+		},
+		{
+			description:   "Single device type, more already allocated to container than requested",
+			podUID:        "fakePod",
+			containerName: "fakeContainer",
+			request: map[string]string{
+				"testdevice": "2",
+			},
+			devices: map[string][]pluginapi.Device{
+				"testdevice": {
+					makeNUMADevice("Dev1", 0),
+					makeNUMADevice("Dev2", 0),
+					makeNUMADevice("Dev3", 1),
+					makeNUMADevice("Dev4", 1),
+				},
+			},
+			allocatedDevices: map[string]map[string]map[string][]string{
+				"fakePod": {
+					"fakeContainer": {
+						"testdevice": {"Dev1", "Dev2", "Dev3", "Dev4"},
+					},
+				},
+			},
+			expectedHints: map[string][]topologymanager.TopologyHint{
+				"testdevice": {},
+			},
+		},
 	}
 
 	for _, tc := range tcases {
@@ -252,6 +377,8 @@ func TestGetTopologyHints(t *testing.T) {
 		}
 
 		pod := makePod(resourceList)
+		pod.UID = types.UID(tc.podUID)
+		pod.Spec.Containers[0].Name = tc.containerName
 
 		m := ManagerImpl{
 			allDevices:       make(map[string]map[string]pluginapi.Device),
@@ -259,7 +386,7 @@ func TestGetTopologyHints(t *testing.T) {
 			allocatedDevices: make(map[string]sets.String),
 			podDevices:       make(podDevices),
 			sourcesReady:     &sourcesReadyStub{},
-			activePods:       func() []*v1.Pod { return []*v1.Pod{} },
+			activePods:       func() []*v1.Pod { return []*v1.Pod{pod} },
 			numaNodes:        []int{0, 1},
 		}
 
@@ -273,13 +400,18 @@ func TestGetTopologyHints(t *testing.T) {
 			}
 		}
 
-		for r := range tc.allocatedDevices {
+		for p := range tc.allocatedDevices {
-			m.allocatedDevices[r] = sets.NewString()
+			for c := range tc.allocatedDevices[p] {
+				for r, devices := range tc.allocatedDevices[p][c] {
+					m.podDevices.insert(p, c, r, sets.NewString(devices...), nil)
 
-			for _, d := range tc.allocatedDevices[r] {
+					m.allocatedDevices[r] = sets.NewString()
+					for _, d := range devices {
 						m.allocatedDevices[r].Insert(d)
 					}
 				}
+			}
+		}
 
 		hints := m.GetTopologyHints(*pod, pod.Spec.Containers[0])