feat(binder): persist fractional GPU compute mode

Signed-off-by: davidLif <davidshani12@gmail.com>

Author: davidLif

.changes/unreleased/added-20260810-112536.yaml

@@ -0,0 +1,3 @@
+kind: Added
+body: |-
+  Persist fractional GPU compute mode

pkg/binder/binding/binder.go

@@ -119,18 +119,22 @@ func (b *Binder) Rollback(ctx context.Context, pod *v1.Pod, node *v1.Node, bindR
 }
 
 func (b *Binder) reserveGPUs(ctx context.Context, pod *v1.Pod, bindRequest *v1alpha2.BindRequest) ([]string, error) {
-	if len(bindRequest.Spec.SelectedGPUGroups) == 0 {
+	fractionalGpuGroups := bindRequest.Spec.SelectedFractionalGpuGroupsOrDefault()
+	if len(fractionalGpuGroups) == 0 {
 		// Old bindingRequest bad conversion. delete the binding request.
-		return nil, fmt.Errorf("no SelectedGPUGroups for fractional pod: %w", InvalidCrdWarning)
+		return nil, fmt.Errorf("no selected GPU groups for fractional pod: %w", InvalidCrdWarning)
 	}
 
 	var gpuIndexes []string
-	for _, gpuGroup := range bindRequest.Spec.SelectedGPUGroups {
-		gpuIndex, err := b.resourceReservationService.ReserveGpuDevice(ctx, pod, bindRequest.Spec.SelectedNode, gpuGroup)
+	for _, fractionalGpuGroup := range fractionalGpuGroups {
+		gpuIndex, err := b.resourceReservationService.ReserveGpuDevice(
+			ctx, pod, bindRequest.Spec.SelectedNode, fractionalGpuGroup)
 		if err != nil {
 			// Cleanup will be handled by the rollback function
 
-			return nil, fmt.Errorf("failed to reserve GPUs for pod <%s/%s> in gpu group <%s>: %w", pod.Namespace, pod.Name, gpuGroup, err)
+			return nil, fmt.Errorf(
+				"failed to reserve GPUs for pod <%s/%s> in gpu group <%s>: %w",
+				pod.Namespace, pod.Name, fractionalGpuGroup.ID, err)
 		}
 		gpuIndexes = append(gpuIndexes, gpuIndex)
 	}

pkg/binder/binding/resourcereservation/mock/resource_reservation_mock.go

@@ -34,16 +34,18 @@ type Interface interface {
 	Sync(ctx context.Context) error
 	SyncForNode(ctx context.Context, nodeName string) error
 	SyncForGpuGroup(ctx context.Context, gpuGroup string) error
-	ReserveGpuDevice(ctx context.Context, pod *v1.Pod, nodeName string, gpuGroup string) (string, error)
+	ReserveGpuDevice(
+		ctx context.Context, pod *v1.Pod, nodeName string,
+		fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
+	) (string, error)
 	RemovePodGpuGroupsConnection(ctx context.Context, pod *v1.Pod) error
 }
 
 const (
-	resourceReservation     = "resource-reservation"
-	gpuReservationPodPrefix = "gpu-reservation"
-	gpuIndexAnnotationName  = "run.ai/reserve_for_gpu_index"
-	numberOfGPUsToReserve   = 1
-	unknownGpuIndicator     = "-1"
+	resourceReservation    = "resource-reservation"
+	gpuIndexAnnotationName = "run.ai/reserve_for_gpu_index"
+	numberOfGPUsToReserve  = 1
+	unknownGpuIndicator    = "-1"
 )
 
 type service struct {
@@ -240,19 +242,23 @@ func (rsc *service) hasActiveBindRequestsForGpuGroup(ctx context.Context, gpuGro
 			br.Status.Phase == schedulingv1alpha2.BindRequestPhaseFailed {
 			continue
 		}
-		if slices.Contains(br.Spec.SelectedGPUGroups, gpuGroup) {
+		if slices.Contains(br.Spec.SelectedFractionalGpuGroupIDs(), gpuGroup) {
 			return true, nil
 		}
 	}
 	return false, nil
 }
-func (rsc *service) ReserveGpuDevice(ctx context.Context, pod *v1.Pod, nodeName string, gpuGroup string) (string, error) {
+func (rsc *service) ReserveGpuDevice(
+	ctx context.Context, pod *v1.Pod, nodeName string, fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
+) (string, error) {
 	logger := log.FromContext(ctx)
+	fractionalGpuGroup = fractionalGpuGroup.WithDefaults()
+	gpuGroup := fractionalGpuGroup.ID
 
 	rsc.gpuGroupMutex.LockMutexForGroup(gpuGroup)
 	defer rsc.gpuGroupMutex.ReleaseMutex(gpuGroup)
 
-	gpuIndex, err := rsc.acquireGPUIndexByGroup(ctx, pod, nodeName, gpuGroup)
+	gpuIndex, err := rsc.acquireGPUIndexByGroup(ctx, nodeName, fractionalGpuGroup)
 	if err != nil {
 		return unknownGpuIndicator, err
 	}
@@ -333,16 +339,16 @@ func escapeJSONPointer(s string) string {
 }
 
 func (rsc *service) acquireGPUIndexByGroup(
-	ctx context.Context, sourcePod *v1.Pod, nodeName, gpuGroup string,
+	ctx context.Context, nodeName string, fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
 ) (string, error) {
-	gpuIndex, err := rsc.findGPUIndexByGroup(gpuGroup)
+	gpuIndex, err := rsc.findGPUIndexByGroup(fractionalGpuGroup.ID)
 	if err != nil {
 		return "", err
 	}
 	if gpuIndex != "" {
 		return gpuIndex, err
 	}
-	return rsc.createGPUReservationPodAndGetIndex(ctx, sourcePod, nodeName, gpuGroup)
+	return rsc.createGPUReservationPodAndGetIndex(ctx, nodeName, fractionalGpuGroup)
 }
 
 func (rsc *service) findGPUIndexByGroup(gpuGroup string) (
@@ -369,11 +375,11 @@ func (rsc *service) findGPUIndexByGroup(gpuGroup string) (
 }
 
 func (rsc *service) createGPUReservationPodAndGetIndex(
-	ctx context.Context, sourcePod *v1.Pod, nodeName, gpuGroup string,
+	ctx context.Context, nodeName string, fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
 ) (
 	gpuIndex string, err error) {
 	logger := log.FromContext(ctx)
-	pod, err := rsc.createGPUReservationPod(ctx, sourcePod, nodeName, gpuGroup)
+	pod, err := rsc.createGPUReservationPod(ctx, nodeName, fractionalGpuGroup)
 	if err != nil {
 		return unknownGpuIndicator, err
 	}
@@ -426,14 +432,14 @@ func (rsc *service) deleteReservationPod(ctx context.Context, pod *v1.Pod) error
 }
 
 func (rsc *service) createGPUReservationPod(
-	ctx context.Context, sourcePod *v1.Pod, nodeName, gpuGroup string,
+	ctx context.Context, nodeName string, fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
 ) (*v1.Pod, error) {
 	logger := log.FromContext(ctx)
 	if rsc.isScalingUp(ctx) {
 		return nil, fmt.Errorf("cluster is scaling up, could not create reservation pod")
 	}
 
-	podName := reservationPodName(nodeName, gpuGroup)
+	podName := reservationPodName(nodeName, fractionalGpuGroup.ID)
 
 	// Build resource requirements starting with GPU resources
 	resources := v1.ResourceRequirements{
@@ -456,15 +462,15 @@ func (rsc *service) createGPUReservationPod(
 		}
 	}
 
-	pod, err := rsc.createResourceReservationPod(sourcePod, nodeName, gpuGroup, podName, resources)
+	pod, err := rsc.createResourceReservationPod(nodeName, fractionalGpuGroup, podName, resources)
 	if err != nil {
 		// The reservation pod name is deterministic per (node, gpu-group). AlreadyExists
 		// means another actor (a concurrent bind, a retry, or another binder replica)
 		// already created the reservation pod for this gpu-group, so reuse it rather than
 		// creating a duplicate on a different physical GPU.
 		if apierrors.IsAlreadyExists(err) {
 			logger.Info("GPU reservation pod already exists for gpu group, reusing",
-				"nodeName", nodeName, "namespace", rsc.namespace, "name", podName, "gpuGroup", gpuGroup)
+				"nodeName", nodeName, "namespace", rsc.namespace, "name", podName, "gpuGroup", fractionalGpuGroup.ID)
 			return pod, nil
 		}
 		logger.Error(err, "Failed to create GPU reservation pod on node",
@@ -531,29 +537,25 @@ func (rsc *service) waitForGPUReservationPodAllocation(
 }
 
 func (rsc *service) createResourceReservationPod(
-	sourcePod *v1.Pod, nodeName, gpuGroup, podName string, resources v1.ResourceRequirements,
+	nodeName string, fractionalGpuGroup schedulingv1alpha2.FractionalGpuGroup,
+	podName string, resources v1.ResourceRequirements,
 ) (*v1.Pod, error) {
-	var tolerations []v1.Toleration
-	if sourcePod != nil {
-		sourcePodSpec := sourcePod.Spec.DeepCopy()
-		tolerations = sourcePodSpec.Tolerations
-	}
-
+	fractionalGpuGroup = fractionalGpuGroup.WithDefaults()
 	podSpec := &v1.Pod{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      podName,
 			Namespace: rsc.namespace,
 			Labels: map[string]string{
 				constants.AppLabelName: rsc.appLabelValue,
-				constants.GPUGroup:     gpuGroup,
+				constants.GPUGroup:     fractionalGpuGroup.ID,
 			},
 			Annotations: map[string]string{
 				karpenterv1.DoNotDisruptAnnotationKey: "true",
+				constants.GpuComputeSharingMode:       string(fractionalGpuGroup.ComputeSharingMode),
 			},
 		},
 		Spec: v1.PodSpec{
-			NodeName:    nodeName,
-			Tolerations: tolerations,
+			NodeName: nodeName,
 			RuntimeClassName: func() *string {
 				if len(rsc.runtimeClassName) == 0 {
 					return nil
@@ -633,7 +635,7 @@ func (rsc *service) isScalingUp(ctx context.Context) bool {
 }
 
 func IsGPUReservationPod(pod *v1.Pod) bool {
-	return strings.HasPrefix(pod.Name, gpuReservationPodPrefix)
+	return strings.HasPrefix(pod.Name, constants.GPUReservationPodPrefix)
 }
 
 // reservationPodName derives a deterministic reservation pod name from the node and
@@ -642,5 +644,5 @@ func IsGPUReservationPod(pod *v1.Pod) bool {
 // pods on different physical GPUs.
 func reservationPodName(nodeName, gpuGroup string) string {
 	hash := sha256.Sum256([]byte(nodeName + "/" + gpuGroup))
-	return fmt.Sprintf("%s-%s", gpuReservationPodPrefix, hex.EncodeToString(hash[:8]))
+	return fmt.Sprintf("%s-%s", constants.GPUReservationPodPrefix, hex.EncodeToString(hash[:8]))
 }