Single-numa-node Topology Manager bug fix

Added one off fix for single-numa-node policy to correctly
reject pod admission on a resource allocation that spans
NUMA nodes

Co-authored-by: Kevin Klues <[email protected]>

Author: lmdaly

pkg/kubelet/cm/topologymanager/topology_manager.go

@@ -231,6 +231,11 @@ func (m *manager) calculateAffinity(pod v1.Pod, container v1.Container) Topology
 				if !hint.Preferred {
 					preferred = false
 				}
+				// Special case PolicySingleNumaNode to only prefer hints where
+				// all providers have a single NUMA affinity set.
+				if m.policy != nil && m.policy.Name() == PolicySingleNumaNode && hint.NUMANodeAffinity.Count() > 1 {
+					preferred = false
+				}
 				numaAffinities = append(numaAffinities, hint.NUMANodeAffinity)
 			}
 		}

pkg/kubelet/cm/topologymanager/topology_manager_test.go

@@ -111,6 +111,7 @@ func TestCalculateAffinity(t *testing.T) {
 		name     string
 		hp       []HintProvider
 		expected TopologyHint
+		policy   Policy
 	}{
 		{
 			name: "TopologyHint not set",
@@ -655,10 +656,45 @@ func TestCalculateAffinity(t *testing.T) {
 				Preferred:        true,
 			},
 		},
+		{
+			name:   "Special cased PolicySingleNumaNode for single NUMA hint generation",
+			policy: NewSingleNumaNodePolicy(),
+			hp: []HintProvider{
+				&mockHintProvider{
+					map[string][]TopologyHint{
+						"resource1": {
+							{
+								NUMANodeAffinity: NewTestSocketMask(0, 1),
+								Preferred:        true,
+							},
+						},
+						"resource2": {
+							{
+								NUMANodeAffinity: NewTestSocketMask(0),
+								Preferred:        true,
+							},
+							{
+								NUMANodeAffinity: NewTestSocketMask(1),
+								Preferred:        true,
+							},
+							{
+								NUMANodeAffinity: NewTestSocketMask(0, 1),
+								Preferred:        false,
+							},
+						},
+					},
+				},
+			},
+			expected: TopologyHint{
+				NUMANodeAffinity: NewTestSocketMask(0),
+				Preferred:        false,
+			},
+		},
 	}
 
 	for _, tc := range tcases {
 		mngr := manager{
+			policy:        tc.policy,
 			hintProviders: tc.hp,
 			numaNodes:     numaNodes,
 		}