Merge pull request #61294 from derekwaynecarr/fix-cfs-quota

Automatic merge from submit-queue (batch tested with PRs 61351, 61294). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fix cpu cfs quota flag with pod cgroups

**What this PR does / why we need it**:
It fixes the cpu-cfs-quota flag in the kubelet when pod cgroups are enabled.

**Which issue(s) this PR fixes** 
Fixes #61293

**Special notes for your reviewer**:
This is a regression reported by some of our users that disable cpu quota enforcement.

**Release note**:
```release-note
Fix regression where kubelet --cpu-cfs-quota flag did not work when --cgroups-per-qos was enabled
```

cmd/kubelet/app/server.go

@@ -661,6 +661,7 @@ func run(s *options.KubeletServer, kubeDeps *kubelet.Dependencies) (err error) {
 				ExperimentalCPUManagerPolicy:          s.CPUManagerPolicy,
 				ExperimentalCPUManagerReconcilePeriod: s.CPUManagerReconcilePeriod.Duration,
 				ExperimentalPodPidsLimit:              s.PodPidsLimit,
+				EnforceCPULimits:                      s.CPUCFSQuota,
 			},
 			s.FailSwapOn,
 			devicePluginEnabled,

pkg/kubelet/cm/container_manager.go

@@ -111,6 +111,7 @@ type NodeConfig struct {
 	ExperimentalCPUManagerPolicy          string
 	ExperimentalCPUManagerReconcilePeriod time.Duration
 	ExperimentalPodPidsLimit              int64
+	EnforceCPULimits                      bool
 }
 
 type NodeAllocatableConfig struct {

pkg/kubelet/cm/container_manager_linux.go

@@ -301,6 +301,7 @@ func (cm *containerManagerImpl) NewPodContainerManager() PodContainerManager {
 			subsystems:        cm.subsystems,
 			cgroupManager:     cm.cgroupManager,
 			podPidsLimit:      cm.ExperimentalPodPidsLimit,
+			enforceCPULimits:  cm.EnforceCPULimits,
 		}
 	}
 	return &podContainerManagerNoop{

pkg/kubelet/cm/helpers_linux.go

@@ -103,7 +103,7 @@ func HugePageLimits(resourceList v1.ResourceList) map[int64]int64 {
 }
 
 // ResourceConfigForPod takes the input pod and outputs the cgroup resource config.
-func ResourceConfigForPod(pod *v1.Pod) *ResourceConfig {
+func ResourceConfigForPod(pod *v1.Pod, enforceCPULimits bool) *ResourceConfig {
 	// sum requests and limits.
 	reqs, limits := resource.PodRequestsAndLimits(pod)
 
@@ -146,6 +146,11 @@ func ResourceConfigForPod(pod *v1.Pod) *ResourceConfig {
 		}
 	}
 
+	// quota is not capped when cfs quota is disabled
+	if !enforceCPULimits {
+		cpuQuota = int64(-1)
+	}
+
 	// determine the qos class
 	qosClass := v1qos.GetPodQOS(pod)
 

pkg/kubelet/cm/helpers_linux_test.go

@@ -57,10 +57,12 @@ func TestResourceConfigForPod(t *testing.T) {
 	guaranteedShares := MilliCPUToShares(100)
 	guaranteedQuota, guaranteedPeriod := MilliCPUToQuota(100)
 	memoryQuantity = resource.MustParse("100Mi")
+	cpuNoLimit := int64(-1)
 	guaranteedMemory := memoryQuantity.Value()
 	testCases := map[string]struct {
-		pod      *v1.Pod
-		expected *ResourceConfig
+		pod              *v1.Pod
+		expected         *ResourceConfig
+		enforceCPULimits bool
 	}{
 		"besteffort": {
 			pod: &v1.Pod{
@@ -72,7 +74,8 @@ func TestResourceConfigForPod(t *testing.T) {
 					},
 				},
 			},
-			expected: &ResourceConfig{CpuShares: &minShares},
+			enforceCPULimits: true,
+			expected:         &ResourceConfig{CpuShares: &minShares},
 		},
 		"burstable-no-limits": {
 			pod: &v1.Pod{
@@ -84,7 +87,8 @@ func TestResourceConfigForPod(t *testing.T) {
 					},
 				},
 			},
-			expected: &ResourceConfig{CpuShares: &burstableShares},
+			enforceCPULimits: true,
+			expected:         &ResourceConfig{CpuShares: &burstableShares},
 		},
 		"burstable-with-limits": {
 			pod: &v1.Pod{
@@ -96,7 +100,21 @@ func TestResourceConfigForPod(t *testing.T) {
 					},
 				},
 			},
-			expected: &ResourceConfig{CpuShares: &burstableShares, CpuQuota: &burstableQuota, CpuPeriod: &burstablePeriod, Memory: &burstableMemory},
+			enforceCPULimits: true,
+			expected:         &ResourceConfig{CpuShares: &burstableShares, CpuQuota: &burstableQuota, CpuPeriod: &burstablePeriod, Memory: &burstableMemory},
+		},
+		"burstable-with-limits-no-cpu-enforcement": {
+			pod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Resources: getResourceRequirements(getResourceList("100m", "100Mi"), getResourceList("200m", "200Mi")),
+						},
+					},
+				},
+			},
+			enforceCPULimits: false,
+			expected:         &ResourceConfig{CpuShares: &burstableShares, CpuQuota: &cpuNoLimit, CpuPeriod: &burstablePeriod, Memory: &burstableMemory},
 		},
 		"burstable-partial-limits": {
 			pod: &v1.Pod{
@@ -111,7 +129,8 @@ func TestResourceConfigForPod(t *testing.T) {
 					},
 				},
 			},
-			expected: &ResourceConfig{CpuShares: &burstablePartialShares},
+			enforceCPULimits: true,
+			expected:         &ResourceConfig{CpuShares: &burstablePartialShares},
 		},
 		"guaranteed": {
 			pod: &v1.Pod{
@@ -123,11 +142,25 @@ func TestResourceConfigForPod(t *testing.T) {
 					},
 				},
 			},
-			expected: &ResourceConfig{CpuShares: &guaranteedShares, CpuQuota: &guaranteedQuota, CpuPeriod: &guaranteedPeriod, Memory: &guaranteedMemory},
+			enforceCPULimits: true,
+			expected:         &ResourceConfig{CpuShares: &guaranteedShares, CpuQuota: &guaranteedQuota, CpuPeriod: &guaranteedPeriod, Memory: &guaranteedMemory},
+		},
+		"guaranteed-no-cpu-enforcement": {
+			pod: &v1.Pod{
+				Spec: v1.PodSpec{
+					Containers: []v1.Container{
+						{
+							Resources: getResourceRequirements(getResourceList("100m", "100Mi"), getResourceList("100m", "100Mi")),
+						},
+					},
+				},
+			},
+			enforceCPULimits: false,
+			expected:         &ResourceConfig{CpuShares: &guaranteedShares, CpuQuota: &cpuNoLimit, CpuPeriod: &guaranteedPeriod, Memory: &guaranteedMemory},
 		},
 	}
 	for testName, testCase := range testCases {
-		actual := ResourceConfigForPod(testCase.pod)
+		actual := ResourceConfigForPod(testCase.pod, testCase.enforceCPULimits)
 		if !reflect.DeepEqual(actual.CpuPeriod, testCase.expected.CpuPeriod) {
 			t.Errorf("unexpected result, test: %v, cpu period not as expected", testName)
 		}

pkg/kubelet/cm/helpers_unsupported.go

@@ -43,7 +43,7 @@ func MilliCPUToShares(milliCPU int64) int64 {
 }
 
 // ResourceConfigForPod takes the input pod and outputs the cgroup resource config.
-func ResourceConfigForPod(pod *v1.Pod) *ResourceConfig {
+func ResourceConfigForPod(pod *v1.Pod, enforceCPULimit bool) *ResourceConfig {
 	return nil
 }
 

pkg/kubelet/cm/pod_container_manager_linux.go

@@ -49,6 +49,8 @@ type podContainerManagerImpl struct {
 	cgroupManager CgroupManager
 	// Maximum number of pids in a pod
 	podPidsLimit int64
+	// enforceCPULimits controls whether cfs quota is enforced or not
+	enforceCPULimits bool
 }
 
 // Make sure that podContainerManagerImpl implements the PodContainerManager interface
@@ -79,7 +81,7 @@ func (m *podContainerManagerImpl) EnsureExists(pod *v1.Pod) error {
 		// Create the pod container
 		containerConfig := &CgroupConfig{
 			Name:               podContainerName,
-			ResourceParameters: ResourceConfigForPod(pod),
+			ResourceParameters: ResourceConfigForPod(pod, m.enforceCPULimits),
 		}
 		if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) && m.podPidsLimit > 0 {
 			containerConfig.ResourceParameters.PodPidsLimit = &m.podPidsLimit