carry: add support for missing uncore cache

no uncore cache can be treated as all CPUs belonging to the same group, so alignment is implicit and always guaranteed. Signed-off-by: Francesco Romani <[email protected]>
openshift · Oct 1, 2024 · 6a21e34 · 6a21e34
1 parent c653eed
commit 6a21e34
Show file tree

Hide file tree

Showing 3 changed files with 65 additions and 2 deletions.
diff --git a/pkg/kubelet/cm/cpumanager/cpu_manager.go b/pkg/kubelet/cm/cpumanager/cpu_manager.go
@@ -157,7 +157,7 @@ func NewManager(cpuPolicyName string, cpuPolicyOptions map[string]string, reconc
 	var policy Policy
 	var err error
 
-	klog.InfoS("LLC alignment available", "version", "2024093001")
+	klog.InfoS("LLC alignment available", "version", "2024100101")
 
 	switch policyName(cpuPolicyName) {
 

diff --git a/pkg/kubelet/cm/cpumanager/topology/topology.go b/pkg/kubelet/cm/cpumanager/topology/topology.go
@@ -337,7 +337,7 @@ func Discover(machineInfo *cadvisorapi.MachineInfo) (*CPUTopology, error) {
 						CoreID:        coreID,
 						SocketID:      core.SocketID,
 						NUMANodeID:    node.Id,
-						UnCoreCacheID: core.UncoreCaches[0].Id,
+						UnCoreCacheID: getUncoreCacheID(core.UncoreCaches),
 					}
 				}
 			} else {
@@ -357,6 +357,19 @@ func Discover(machineInfo *cadvisorapi.MachineInfo) (*CPUTopology, error) {
 	}, nil
 }
 
+const (
+	NullUncoreCacheID int = 65535 // TODO: "high enough" value to signal "impossible"
+)
+
+func getUncoreCacheID(uncoreCaches []cadvisorapi.Cache) int {
+	if len(uncoreCaches) < 1 {
+		return NullUncoreCacheID
+	}
+	// Even though cadvisor API returns a slice, we only expect either 0 or 1 uncore caches,
+	// so everything past first entry should be discarded
+	return uncoreCaches[0].Id
+}
+
 // getUniqueCoreID computes coreId as the lowest cpuID
 // for a given Threads []int slice. This will assure that coreID's are
 // platform unique (opposite to what cAdvisor reports)

diff --git a/pkg/kubelet/cm/cpumanager/topology/topology_test.go b/pkg/kubelet/cm/cpumanager/topology/topology_test.go
@@ -1379,3 +1379,53 @@ func TestCPUNUMANodeID(t *testing.T) {
 		})
 	}
 }
+
+func Test_getUncoreCacheID(t *testing.T) {
+	tests := []struct {
+		name         string
+		uncoreCaches []cadvisorapi.Cache
+		expectedID   int
+	}{
+		{
+			name:       "nil",
+			expectedID: NullUncoreCacheID,
+		},
+		{
+			name:         "empty",
+			uncoreCaches: []cadvisorapi.Cache{},
+			expectedID:   NullUncoreCacheID,
+		},
+		{
+			name: "one-entry",
+			uncoreCaches: []cadvisorapi.Cache{
+				{
+					Id: 42,
+				},
+			},
+			expectedID: 42,
+		},
+		{
+			name: "multi-entries",
+			uncoreCaches: []cadvisorapi.Cache{
+				{
+					Id: 1,
+				},
+				{
+					Id: 12,
+				},
+				{
+					Id: 42,
+				},
+			},
+			expectedID: 1,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := getUncoreCacheID(tt.uncoreCaches)
+			if got != tt.expectedID {
+				t.Errorf("getUncoreCacheID = %v expected %v", got, tt.expectedID)
+			}
+		})
+	}
+}