Merge pull request #74859 from ahadas/static_policy

kubelet/cm: code optimization for the static policy

pkg/kubelet/cm/cpumanager/cpu_assignment.go

@@ -158,25 +158,31 @@ func takeByTopology(topo *topology.CPUTopology, availableCPUs cpuset.CPUSet, num
 	// Algorithm: topology-aware best-fit
 	// 1. Acquire whole sockets, if available and the container requires at
 	//    least a socket's-worth of CPUs.
-	for _, s := range acc.freeSockets() {
 	if acc.needs(acc.topo.CPUsPerSocket()) {
+		for _, s := range acc.freeSockets() {
 			klog.V(4).Infof("[cpumanager] takeByTopology: claiming socket [%d]", s)
 			acc.take(acc.details.CPUsInSocket(s))
 			if acc.isSatisfied() {
 				return acc.result, nil
 			}
+			if !acc.needs(acc.topo.CPUsPerSocket()) {
+				break
+			}
 		}
 	}
 
 	// 2. Acquire whole cores, if available and the container requires at least
 	//    a core's-worth of CPUs.
-	for _, c := range acc.freeCores() {
 	if acc.needs(acc.topo.CPUsPerCore()) {
+		for _, c := range acc.freeCores() {
 			klog.V(4).Infof("[cpumanager] takeByTopology: claiming core [%d]", c)
 			acc.take(acc.details.CPUsInCore(c))
 			if acc.isSatisfied() {
 				return acc.result, nil
 			}
+			if !acc.needs(acc.topo.CPUsPerCore()) {
+				break
+			}
 		}
 	}
 

pkg/kubelet/cm/cpumanager/cpu_assignment_test.go

@@ -356,7 +356,7 @@ func TestTakeByTopology(t *testing.T) {
 			cpuset.NewCPUSet(2, 6),
 		},
 		{
-			"take three cpus from dual socket with HT - core from Socket 0",
+			"take one cpu from dual socket with HT - core from Socket 0",
 			topoDualSocketHT,
 			cpuset.NewCPUSet(1, 2, 3, 4, 5, 7, 8, 9, 10, 11),
 			1,