Avoid using socket for hints

Sockets don't affect performance as NUMA node does, since NUMA
node has dedicated memory controller, but socket it's physical
extension point.
Socket it's only cpu specific thing and it's strange to merge bitmask of
deviceplugin's and cpu manager, when cpu manager takes into account
socket.

Signed-off-by: Alexey Perevalov <[email protected]>

Author: AlexeyPerevalov

pkg/kubelet/cm/cpumanager/policy_static.go

@@ -364,24 +364,18 @@ func (p *staticPolicy) GetTopologyHints(s state.State, pod *v1.Pod, container *v
 func (p *staticPolicy) generateCPUTopologyHints(availableCPUs cpuset.CPUSet, reusableCPUs cpuset.CPUSet, request int) []topologymanager.TopologyHint {
 	// Initialize minAffinitySize to include all NUMA Nodes.
 	minAffinitySize := p.topology.CPUDetails.NUMANodes().Size()
-	// Initialize minSocketsOnMinAffinity to include all Sockets.
-	minSocketsOnMinAffinity := p.topology.CPUDetails.Sockets().Size()
 
-	// Iterate through all combinations of socket bitmask and build hints from them.
+	// Iterate through all combinations of numa nodes bitmask and build hints from them.
 	hints := []topologymanager.TopologyHint{}
 	bitmask.IterateBitMasks(p.topology.CPUDetails.NUMANodes().ToSlice(), func(mask bitmask.BitMask) {
-		// First, update minAffinitySize and minSocketsOnMinAffinity for the
-		// current request size.
+		// First, update minAffinitySize for the current request size.
 		cpusInMask := p.topology.CPUDetails.CPUsInNUMANodes(mask.GetBits()...).Size()
-		socketsInMask := p.topology.CPUDetails.SocketsInNUMANodes(mask.GetBits()...).Size()
 		if cpusInMask >= request && mask.Count() < minAffinitySize {
 			minAffinitySize = mask.Count()
-			if socketsInMask < minSocketsOnMinAffinity {
-				minSocketsOnMinAffinity = socketsInMask
-			}
 		}
 
-		// Then check to see if all of the reusable CPUs are part of the bitmask.
+		// Then check to see if we have enough CPUs available on the current
+		// numa node bitmask to satisfy the CPU request.
 		numMatching := 0
 		for _, c := range reusableCPUs.ToSlice() {
 			// Disregard this mask if its NUMANode isn't part of it.
@@ -404,7 +398,7 @@ func (p *staticPolicy) generateCPUTopologyHints(availableCPUs cpuset.CPUSet, reu
 			return
 		}
 
-		// Otherwise, create a new hint from the socket bitmask and add it to the
+		// Otherwise, create a new hint from the numa node bitmask and add it to the
 		// list of hints.  We set all hint preferences to 'false' on the first
 		// pass through.
 		hints = append(hints, topologymanager.TopologyHint{
@@ -416,14 +410,10 @@ func (p *staticPolicy) generateCPUTopologyHints(availableCPUs cpuset.CPUSet, reu
 	// Loop back through all hints and update the 'Preferred' field based on
 	// counting the number of bits sets in the affinity mask and comparing it
 	// to the minAffinitySize. Only those with an equal number of bits set (and
-	// with a minimal set of sockets) will be considered preferred.
+	// with a minimal set of numa nodes) will be considered preferred.
 	for i := range hints {
 		if hints[i].NUMANodeAffinity.Count() == minAffinitySize {
-			nodes := hints[i].NUMANodeAffinity.GetBits()
-			numSockets := p.topology.CPUDetails.SocketsInNUMANodes(nodes...).Size()
-			if numSockets == minSocketsOnMinAffinity {
-				hints[i].Preferred = true
-			}
+			hints[i].Preferred = true
 		}
 	}