Make iterateAllProviderTopologyHints generic:

- Remove policy parameters to make this function generic.
- Move function out of individual policies and into policy.go

pkg/kubelet/cm/topologymanager/policy.go

@@ -28,3 +28,41 @@ type Policy interface {
 	// and a Pod Admit Handler Response based on hints and policy type
 	Merge(providersHints []map[string][]TopologyHint) (TopologyHint, lifecycle.PodAdmitResult)
 }
+
+// Iterate over all permutations of hints in 'allProviderHints [][]TopologyHint'.
+//
+// This procedure is implemented as a recursive function over the set of hints
+// in 'allproviderHints[i]'. It applies the function 'callback' to each
+// permutation as it is found. It is the equivalent of:
+//
+// for i := 0; i < len(providerHints[0]); i++
+//     for j := 0; j < len(providerHints[1]); j++
+//         for k := 0; k < len(providerHints[2]); k++
+//             ...
+//             for z := 0; z < len(providerHints[-1]); z++
+//                 permutation := []TopologyHint{
+//                     providerHints[0][i],
+//                     providerHints[1][j],
+//                     providerHints[2][k],
+//                     ...
+//                     providerHints[-1][z]
+//                 }
+//                 callback(permutation)
+func iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback func([]TopologyHint)) {
+	// Internal helper function to accumulate the permutation before calling the callback.
+	var iterate func(i int, accum []TopologyHint)
+	iterate = func(i int, accum []TopologyHint) {
+		// Base case: we have looped through all providers and have a full permutation.
+		if i == len(allProviderHints) {
+			callback(accum)
+			return
+		}
+
+		// Loop through all hints for provider 'i', and recurse to build the
+		// the permutation of this hint with all hints from providers 'i++'.
+		for j := range allProviderHints[i] {
+			iterate(i+1, append(accum, allProviderHints[i][j]))
+		}
+	}
+	iterate(0, []TopologyHint{})
+}

pkg/kubelet/cm/topologymanager/policy_best_effort.go

@@ -53,44 +53,6 @@ func (p *bestEffortPolicy) Merge(providersHints []map[string][]TopologyHint) (To
 	return hint, admit
 }
 
-// Iterate over all permutations of hints in 'allProviderHints [][]TopologyHint'.
-//
-// This procedure is implemented as a recursive function over the set of hints
-// in 'allproviderHints[i]'. It applies the function 'callback' to each
-// permutation as it is found. It is the equivalent of:
-//
-// for i := 0; i < len(providerHints[0]); i++
-//     for j := 0; j < len(providerHints[1]); j++
-//         for k := 0; k < len(providerHints[2]); k++
-//             ...
-//             for z := 0; z < len(providerHints[-1]); z++
-//                 permutation := []TopologyHint{
-//                     providerHints[0][i],
-//                     providerHints[1][j],
-//                     providerHints[2][k],
-//                     ...
-//                     providerHints[-1][z]
-//                 }
-//                 callback(permutation)
-func (p *bestEffortPolicy) iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback func([]TopologyHint)) {
-	// Internal helper function to accumulate the permutation before calling the callback.
-	var iterate func(i int, accum []TopologyHint)
-	iterate = func(i int, accum []TopologyHint) {
-		// Base case: we have looped through all providers and have a full permutation.
-		if i == len(allProviderHints) {
-			callback(accum)
-			return
-		}
-
-		// Loop through all hints for provider 'i', and recurse to build the
-		// the permutation of this hint with all hints from providers 'i++'.
-		for j := range allProviderHints[i] {
-			iterate(i+1, append(accum, allProviderHints[i][j]))
-		}
-	}
-	iterate(0, []TopologyHint{})
-}
-
 // Merge a TopologyHints permutation to a single hint by performing a bitwise-AND
 // of their affinity masks. The hint shall be preferred if all hits in the permutation
 // are preferred.
@@ -163,7 +125,7 @@ func (p *bestEffortPolicy) mergeProvidersHints(providersHints []map[string][]Top
 	// permutations that have at least one NUMA ID set. If no merged mask can be
 	// found that has at least one NUMA ID set, return the 'defaultAffinity'.
 	bestHint := TopologyHint{defaultAffinity, false}
-	p.iterateAllProviderTopologyHints(allProviderHints, func(permutation []TopologyHint) {
+	iterateAllProviderTopologyHints(allProviderHints, func(permutation []TopologyHint) {
 		// Get the NUMANodeAffinity from each hint in the permutation and see if any
 		// of them encode unpreferred allocations.
 		mergedHint := p.mergePermutation(permutation)

pkg/kubelet/cm/topologymanager/policy_single_numa_node.go

@@ -54,44 +54,6 @@ func (p *singleNumaNodePolicy) canAdmitPodResult(hint *TopologyHint) lifecycle.P
 	}
 }
 
-// Iterate over all permutations of hints in 'allProviderHints [][]TopologyHint'.
-//
-// This procedure is implemented as a recursive function over the set of hints
-// in 'allproviderHints[i]'. It applies the function 'callback' to each
-// permutation as it is found. It is the equivalent of:
-//
-// for i := 0; i < len(providerHints[0]); i++
-//     for j := 0; j < len(providerHints[1]); j++
-//         for k := 0; k < len(providerHints[2]); k++
-//             ...
-//             for z := 0; z < len(providerHints[-1]); z++
-//                 permutation := []TopologyHint{
-//                     providerHints[0][i],
-//                     providerHints[1][j],
-//                     providerHints[2][k],
-//                     ...
-//                     providerHints[-1][z]
-//                 }
-//                 callback(permutation)
-func (p *singleNumaNodePolicy) iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback func([]TopologyHint)) {
-	// Internal helper function to accumulate the permutation before calling the callback.
-	var iterate func(i int, accum []TopologyHint)
-	iterate = func(i int, accum []TopologyHint) {
-		// Base case: we have looped through all providers and have a full permutation.
-		if i == len(allProviderHints) {
-			callback(accum)
-			return
-		}
-
-		// Loop through all hints for provider 'i', and recurse to build the
-		// the permutation of this hint with all hints from providers 'i++'.
-		for j := range allProviderHints[i] {
-			iterate(i+1, append(accum, allProviderHints[i][j]))
-		}
-	}
-	iterate(0, []TopologyHint{})
-}
-
 // Merge a TopologyHints permutation to a single hint by performing a bitwise-AND
 // of their affinity masks. At this point, all hints have single numa node affinity
 // and preferred-true.
@@ -203,7 +165,7 @@ func (p *singleNumaNodePolicy) mergeProvidersHints(providersHints []map[string][
 	// no better hint can be found when merging hints from each hint provider.
 	defaultAffinity, _ := bitmask.NewBitMask(p.numaNodes...)
 	bestHint := TopologyHint{defaultAffinity, false}
-	p.iterateAllProviderTopologyHints(allResourcesHints, func(permutation []TopologyHint) {
+	iterateAllProviderTopologyHints(allResourcesHints, func(permutation []TopologyHint) {
 		mergedHint := p.mergePermutation(permutation)
 		// Only consider mergedHints that result in a NUMANodeAffinity == 1 to
 		// replace the current defaultHint.