Make mergeProviderHints policy-specific:

- Remove need to pass policy and numaNodes as arguments
- Remove PolicySingleNUMANode special case check in policy_best_effort
- Add mergeProviderHints base to policy_single_numa_node for upcoming
commit

pkg/kubelet/cm/topologymanager/policy_best_effort.go

@@ -48,7 +48,7 @@ func (p *bestEffortPolicy) canAdmitPodResult(hint *TopologyHint) lifecycle.PodAd
 }
 
 func (p *bestEffortPolicy) Merge(providersHints []map[string][]TopologyHint) (TopologyHint, lifecycle.PodAdmitResult) {
-	hint := mergeProvidersHints(p, p.numaNodes, providersHints)
+	hint := p.mergeProvidersHints(providersHints)
 	admit := p.canAdmitPodResult(&hint)
 	return hint, admit
 }
@@ -72,7 +72,7 @@ func (p *bestEffortPolicy) Merge(providersHints []map[string][]TopologyHint) (To
 //                     providerHints[-1][z]
 //                 }
 //                 callback(permutation)
-func iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback func([]TopologyHint)) {
+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) {
@@ -94,10 +94,10 @@ func iterateAllProviderTopologyHints(allProviderHints [][]TopologyHint, callback
 // 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.
-func mergePermutation(policy Policy, numaNodes []int, permutation []TopologyHint) TopologyHint {
+func (p *bestEffortPolicy) mergePermutation(permutation []TopologyHint) TopologyHint {
 	// Get the NUMANodeAffinity from each hint in the permutation and see if any
 	// of them encode unpreferred allocations.
-	defaultAffinity, _ := bitmask.NewBitMask(numaNodes...)
+	defaultAffinity, _ := bitmask.NewBitMask(p.numaNodes...)
 	preferred := true
 	var numaAffinities []bitmask.BitMask
 	for _, hint := range permutation {
@@ -111,17 +111,10 @@ func mergePermutation(policy Policy, numaNodes []int, permutation []TopologyHint
 		if !hint.Preferred {
 			preferred = false
 		}
-
-		// Special case PolicySingleNumaNode to only prefer hints where
-		// all providers have a single NUMA affinity set.
-		if policy != nil && policy.Name() == PolicySingleNumaNode && hint.NUMANodeAffinity != nil && hint.NUMANodeAffinity.Count() > 1 {
-			preferred = false
-		}
-
 	}
 
 	// Merge the affinities using a bitwise-and operation.
-	mergedAffinity, _ := bitmask.NewBitMask(numaNodes...)
+	mergedAffinity, _ := bitmask.NewBitMask(p.numaNodes...)
 	mergedAffinity.And(numaAffinities...)
 	// Build a mergedHint from the merged affinity mask, indicating if an
 	// preferred allocation was used to generate the affinity mask or not.
@@ -129,10 +122,10 @@ func mergePermutation(policy Policy, numaNodes []int, permutation []TopologyHint
 }
 
 // Merge the hints from all hint providers to find the best one.
-func mergeProvidersHints(policy Policy, numaNodes []int, providersHints []map[string][]TopologyHint) TopologyHint {
+func (p *bestEffortPolicy) mergeProvidersHints(providersHints []map[string][]TopologyHint) TopologyHint {
 	// Set the default affinity as an any-numa affinity containing the list
 	// of NUMA Nodes available on this machine.
-	defaultAffinity, _ := bitmask.NewBitMask(numaNodes...)
+	defaultAffinity, _ := bitmask.NewBitMask(p.numaNodes...)
 
 	// Loop through all hint providers and save an accumulated list of the
 	// hints returned by each hint provider. If no hints are provided, assume
@@ -170,10 +163,10 @@ func mergeProvidersHints(policy Policy, numaNodes []int, providersHints []map[st
 	// 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}
-	iterateAllProviderTopologyHints(allProviderHints, func(permutation []TopologyHint) {
+	p.iterateAllProviderTopologyHints(allProviderHints, func(permutation []TopologyHint) {
 		// Get the NUMANodeAffinity from each hint in the permutation and see if any
 		// of them encode unpreferred allocations.
-		mergedHint := mergePermutation(policy, numaNodes, permutation)
+		mergedHint := p.mergePermutation(permutation)
 
 		// Only consider mergedHints that result in a NUMANodeAffinity > 0 to
 		// replace the current bestHint.

pkg/kubelet/cm/topologymanager/policy_restricted.go

@@ -52,7 +52,7 @@ func (p *restrictedPolicy) canAdmitPodResult(hint *TopologyHint) lifecycle.PodAd
 }
 
 func (p *restrictedPolicy) Merge(providersHints []map[string][]TopologyHint) (TopologyHint, lifecycle.PodAdmitResult) {
-	hint := mergeProvidersHints(p, p.numaNodes, providersHints)
+	hint := p.mergeProvidersHints(providersHints)
 	admit := p.canAdmitPodResult(&hint)
 	return hint, admit
 }

pkg/kubelet/cm/topologymanager/policy_single_numa_node.go

@@ -17,6 +17,7 @@ limitations under the License.
 package topologymanager
 
 import (
+	"k8s.io/kubernetes/pkg/kubelet/cm/topologymanager/bitmask"
 	"k8s.io/kubernetes/pkg/kubelet/lifecycle"
 )
 
@@ -52,8 +53,17 @@ func (p *singleNumaNodePolicy) canAdmitPodResult(hint *TopologyHint) lifecycle.P
 	}
 }
 
+func (p *singleNumaNodePolicy) mergeProvidersHints(providersHints []map[string][]TopologyHint) TopologyHint {
+	// Set the default hint to return from this function as an any-NUMANode
+	// affinity with an unpreferred allocation. This will only be returned if
+	// no better hint can be found when merging hints from each hint provider.
+	defaultAffinity, _ := bitmask.NewBitMask(p.numaNodes...)
+	defaultHint := TopologyHint{defaultAffinity, false}
+	return defaultHint
+}
+
 func (p *singleNumaNodePolicy) Merge(providersHints []map[string][]TopologyHint) (TopologyHint, lifecycle.PodAdmitResult) {
-	hint := mergeProvidersHints(p, p.numaNodes, providersHints)
+	hint := p.mergeProvidersHints(providersHints)
 	admit := p.canAdmitPodResult(&hint)
 	return hint, admit
 }