func resourcesAvailableInAnyNUMANodes()

in pkg/noderesourcetopology/filter.go [89:155]
43 lines of code
10 McCabe index (conditional complexity)

func resourcesAvailableInAnyNUMANodes(lh logr.Logger, numaNodes NUMANodeList, resources v1.ResourceList, qos v1.PodQOSClass, nodeInfo *framework.NodeInfo) (int, bool) {
	numaID := highestNUMAID
	bitmask := bm.NewEmptyBitMask()
	// set all bits, each bit is a NUMA node, if resources couldn't be aligned
	// on the NUMA node, bit should be unset
	bitmask.Fill()

	nodeResources := util.ResourceList(nodeInfo.Allocatable)

	for resource, quantity := range resources {
		if quantity.IsZero() {
			// why bother? everything's fine from the perspective of this resource
			lh.V(4).Info("ignoring zero-qty resource request", "resource", resource)
			continue
		}

		if _, ok := nodeResources[resource]; !ok {
			// some resources may not expose NUMA affinity (device plugins, extended resources), but all resources
			// must be reported at node level; thus, if they are not present at node level, we can safely assume
			// we don't have the resource at all.
			lh.V(2).Info("early verdict: cannot meet request", "resource", resource, "suitable", "false")
			return numaID, false
		}

		// for each requested resource, calculate which NUMA slots are good fits, and then AND with the aggregated bitmask, IOW unset appropriate bit if we can't align resources, or set it
		// obvious, bits which are not in the NUMA id's range would be unset
		hasNUMAAffinity := false
		resourceBitmask := bm.NewEmptyBitMask()
		for _, numaNode := range numaNodes {
			numaQuantity, ok := numaNode.Resources[resource]
			if !ok {
				continue
			}

			hasNUMAAffinity = true
			if !isResourceSetSuitable(qos, resource, quantity, numaQuantity) {
				continue
			}

			resourceBitmask.Add(numaNode.NUMAID)
			lh.V(6).Info("feasible", "numaCell", numaNode.NUMAID, "resource", resource)
		}

		// non-native resources or ephemeral-storage may not expose NUMA affinity,
		// but since they are available at node level, this is fine
		if !hasNUMAAffinity && isHostLevelResource(resource) {
			lh.V(6).Info("resource available at host level (no NUMA affinity)", "resource", resource)
			continue
		}

		bitmask.And(resourceBitmask)
		if bitmask.IsEmpty() {
			lh.V(2).Info("early verdict", "resource", resource, "suitable", "false")
			return numaID, false
		}
	}
	// according to TopologyManager, the preferred NUMA affinity, is the narrowest one.
	// https://github.com/kubernetes/kubernetes/blob/v1.24.0-rc.1/pkg/kubelet/cm/topologymanager/policy.go#L155
	// in single-numa-node policy all resources should be allocated from a single NUMA,
	// which means that the lowest NUMA ID (with available resources) is the one to be selected by Kubelet.
	numaID = bitmask.GetBits()[0]

	// at least one NUMA node is available
	ret := !bitmask.IsEmpty()
	lh.V(2).Info("final verdict", "suitable", ret)
	return numaID, ret
}