controller: add support for 64k-pages kernel on aarch64

This commit consist of the following changes:
* Enhanced the performanceprofile controller to choose 64k-pages MC kernelType, when 64K pages specified.
* Added unit tests to cover the following scenarios:
 RealTime kernel disabled + 64K => 64-pages kernelType
 RealTime kernel disabled + 4K => default kernelType
 RealTime kernel enabled + 4K => realtime kernelType

Note that the case of RealTime kernel enabled + 64K is not tested, as it is expected to be rejected by validation.

Signed-off-by: Ronny Baturov <[email protected]>

pkg/performanceprofile/controller/performanceprofile/components/machineconfig/machineconfig.go

@@ -37,6 +37,8 @@ const (
 	MCKernelRT = "realtime"
 	// MCKernelDefault is the value of the kernel setting in MachineConfig for the default kernel
 	MCKernelDefault = "default"
+	// MCKernel64kPages is the value of the kernel setting in MachineConfig for 64k-pages kernel on aarch64
+	MCKernel64kPages = "64k-pages"
 	// HighPerformanceRuntime contains the name of the high-performance runtime
 	HighPerformanceRuntime = "high-performance"
 
@@ -146,8 +148,14 @@ func New(profile *performancev2.PerformanceProfile, opts *components.MachineConf
 		profile.Spec.RealTimeKernel.Enabled != nil &&
 		*profile.Spec.RealTimeKernel.Enabled
 
+	// Real time kernel with 64k-pages for aarch64 not yet supported and rejected in the validation webhook.
 	if enableRTKernel {
 		mc.Spec.KernelType = MCKernelRT
+
+	} else if profile.Spec.KernelPageSize != nil && *profile.Spec.KernelPageSize == performancev2.KernelPageSize("64K") {
+		// During validation, we ensure that nodes are based on aarch64 when the administrator specifies 64K for this field.
+		// Hence, this assignment is guaranteed to be safe.
+		mc.Spec.KernelType = MCKernel64kPages
 	} else {
 		mc.Spec.KernelType = MCKernelDefault
 	}

pkg/performanceprofile/controller/performanceprofile_controller_test.go

@@ -395,24 +395,31 @@ var _ = Describe("Controller", func() {
 					}
 				})
 
-				It("should update MC when RT kernel gets disabled", func() {
-					profile.Spec.RealTimeKernel.Enabled = ptr.To(false)
-					r := newFakeReconciler(profile, mc, kc, tunedPerformance, profileMCP, infra, clusterOperator)
-
-					Expect(reconcileTimes(r, request, 1)).To(Equal(reconcile.Result{}))
-
-					key := types.NamespacedName{
-						Name:      machineconfig.GetMachineConfigName(profile.Name),
-						Namespace: metav1.NamespaceNone,
-					}
-
-					// verify MachineConfig update
-					mc := &mcov1.MachineConfig{}
-					err := r.Get(context.TODO(), key, mc)
-					Expect(err).ToNot(HaveOccurred())
-
-					Expect(mc.Spec.KernelType).To(Equal(machineconfig.MCKernelDefault))
-				})
+				DescribeTable("MachineConfig kernelType updates",
+					func(rtKernelEnabled bool, kernelPageSize *performancev2.KernelPageSize, expectedKernelType string) {
+						// Set up profile
+						profile.Spec.RealTimeKernel.Enabled = ptr.To(rtKernelEnabled)
+						profile.Spec.KernelPageSize = kernelPageSize
+
+						r := newFakeReconciler(profile, mc, kc, tunedPerformance, profileMCP, infra, clusterOperator)
+
+						Expect(reconcileTimes(r, request, 1)).To(Equal(reconcile.Result{}))
+
+						// Verify MachineConfig update
+						key := types.NamespacedName{
+							Name:      machineconfig.GetMachineConfigName(profile.Name),
+							Namespace: metav1.NamespaceNone,
+						}
+
+						mc := &mcov1.MachineConfig{}
+						err := r.Get(context.TODO(), key, mc)
+						Expect(err).ToNot(HaveOccurred())
+						Expect(mc.Spec.KernelType).To(Equal(expectedKernelType))
+					},
+					Entry("should set kernelType to default when RealTimeKernel is disabled", false, nil, machineconfig.MCKernelDefault),
+					Entry("should set kernelType to 64k-pages when RT kernel disabled and 64K kernel page size selected", false, ptr.To(performancev2.KernelPageSize("64K")), machineconfig.MCKernel64kPages),
+					Entry("should set kernelType to realtime when RT kernel is enabled", true, nil, machineconfig.MCKernelRT),
+				)
 
 				It("should update MC, KC and Tuned when CPU params change", func() {
 					reserved := performancev2.CPUSet("0-1")