nrt: filter: distinguish host-level resources

"host-level" resources are resources which are not
expected to have NUMA affinity. This means
that these resources not showing up in per-NUMA
resource counters should not prevent per se scheduling
on a given node.

Signed-off-by: Francesco Romani <[email protected]>

Author: ffromani

pkg/noderesourcetopology/filter.go

@@ -132,8 +132,8 @@ func resourcesAvailableInAnyNUMANodes(lh logr.Logger, numaNodes NUMANodeList, re
 
 		// non-native resources or ephemeral-storage may not expose NUMA affinity,
 		// but since they are available at node level, this is fine
-		if !hasNUMAAffinity && (!v1helper.IsNativeResource(resource) || resource == v1.ResourceEphemeralStorage) {
-			lh.V(6).Info("resource available at node level (no NUMA affinity)", "resource", resource)
+		if !hasNUMAAffinity && isHostLevelResource(resource) {
+			lh.V(6).Info("resource available at host level (no NUMA affinity)", "resource", resource)
 			continue
 		}
 

pkg/noderesourcetopology/numaresources.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package noderesourcetopology
+
+import (
+	corev1 "k8s.io/api/core/v1"
+	v1helper "k8s.io/kubernetes/pkg/apis/core/v1/helper"
+)
+
+func isHostLevelResource(resource corev1.ResourceName) bool {
+	// host-level resources are resources which *may* not be bound to NUMA nodes.
+	// A Key example is generic [ephemeral] storage which doesn't expose NUMA affinity.
+	if resource == corev1.ResourceEphemeralStorage {
+		return true
+	}
+	if resource == corev1.ResourceStorage {
+		return true
+	}
+	if !v1helper.IsNativeResource(resource) {
+		return true
+	}
+	return false
+}

pkg/noderesourcetopology/numaresources_test.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package noderesourcetopology
+
+import (
+	"testing"
+
+	corev1 "k8s.io/api/core/v1"
+)
+
+func TestIsHostLevelResource(t *testing.T) {
+	testCases := []struct {
+		resource corev1.ResourceName
+		expected bool
+	}{
+		{
+			resource: corev1.ResourceCPU,
+			expected: false,
+		},
+		{
+			resource: corev1.ResourceMemory,
+			expected: false,
+		},
+		{
+			resource: corev1.ResourceName("hugepages-1Gi"),
+			expected: false,
+		},
+		{
+			resource: corev1.ResourceStorage,
+			expected: true,
+		},
+		{
+			resource: corev1.ResourceEphemeralStorage,
+			expected: true,
+		},
+		{
+			resource: corev1.ResourceName("vendor.io/fastest-nic"),
+			expected: true,
+		},
+		{
+			resource: corev1.ResourceName("awesome.com/gpu-for-ai"),
+			expected: true,
+		},
+	}
+	for _, testCase := range testCases {
+		t.Run(string(testCase.resource), func(t *testing.T) {
+			got := isHostLevelResource(testCase.resource)
+			if got != testCase.expected {
+				t.Fatalf("expected %t to equal %t", got, testCase.expected)
+			}
+		})
+	}
+}