func resMatchNUMANodes()

in pkg/noderesourcetopology/filter.go [104:142]

• 26 lines of code
• 12 McCabe index (conditional complexity)

func resMatchNUMANodes(nodes NUMANodeList, resources v1.ResourceList, qos v1.PodQOSClass) bool {
	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()

	zeroQuantity := resource.MustParse("0")
	for resource, quantity := range resources {
		// 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
		resourceBitmask := bm.NewEmptyBitMask()
		for _, numaNode := range nodes {
			numaQuantity, ok := numaNode.Resources[resource]
			// if can't find requested resource on the node - skip (don't set it as available NUMA node)
			// if unfound resource has 0 quantity probably this numa node can be considered
			if !ok && quantity.Cmp(zeroQuantity) != 0 {
				continue
			}
			// Check for the following:
			// 1. set numa node as possible node if resource is memory or Hugepages
			// 2. set numa node as possible node if resource is cpu and it's not guaranteed QoS, since cpu will flow
			// 3. set numa node as possible node if zero quantity for non existing resource was requested
			// 4. otherwise check amount of resources
			if resource == v1.ResourceMemory ||
				strings.HasPrefix(string(resource), v1.ResourceHugePagesPrefix) ||
				resource == v1.ResourceCPU && qos != v1.PodQOSGuaranteed ||
				quantity.Cmp(zeroQuantity) == 0 ||
				numaQuantity.Cmp(quantity) >= 0 {
				// possible to align resources on NUMA node
				resourceBitmask.Add(numaNode.NUMAID)
			}
		}
		bitmask.And(resourceBitmask)
		if bitmask.IsEmpty() {
			return true
		}
	}
	return bitmask.IsEmpty()
}