From f798cee51e9b194a416945f28e97b98ceb6ff7c3 Mon Sep 17 00:00:00 2001
From: Paul Fisher <pfisher@lyft.com>
Date: Fri, 30 Aug 2019 09:58:59 -0700
Subject: [PATCH 1/2] pkg/kubelet: fix uint64 overflow when elapsed
 UsageCoreNanoSeconds exceeds 18446744073

---
 pkg/kubelet/stats/cri_stats_provider.go      |  3 ++-
 pkg/kubelet/stats/cri_stats_provider_test.go | 26 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/pkg/kubelet/stats/cri_stats_provider.go b/pkg/kubelet/stats/cri_stats_provider.go
index 492c16bbd77..7c23166be36 100644
--- a/pkg/kubelet/stats/cri_stats_provider.go
+++ b/pkg/kubelet/stats/cri_stats_provider.go
@@ -661,7 +661,8 @@ func (p *criStatsProvider) getAndUpdateContainerUsageNanoCores(stats *runtimeapi
 		if nanoSeconds <= 0 {
 			return nil, fmt.Errorf("zero or negative interval (%v - %v)", newStats.Timestamp, cachedStats.Timestamp)
 		}
-		usageNanoCores := (newStats.UsageCoreNanoSeconds.Value - cachedStats.UsageCoreNanoSeconds.Value) * uint64(time.Second/time.Nanosecond) / uint64(nanoSeconds)
+		usageNanoCores := uint64(float64(newStats.UsageCoreNanoSeconds.Value-cachedStats.UsageCoreNanoSeconds.Value) /
+			float64(nanoSeconds) * float64(time.Second/time.Nanosecond))
 
 		// Update cache with new value.
 		usageToUpdate := usageNanoCores
diff --git a/pkg/kubelet/stats/cri_stats_provider_test.go b/pkg/kubelet/stats/cri_stats_provider_test.go
index 8d65e71ea4c..cf7852705a5 100644
--- a/pkg/kubelet/stats/cri_stats_provider_test.go
+++ b/pkg/kubelet/stats/cri_stats_provider_test.go
@@ -757,6 +757,7 @@ func makeFakeLogStats(seed int) *volume.Metrics {
 func TestGetContainerUsageNanoCores(t *testing.T) {
 	var value0 uint64
 	var value1 uint64 = 10000000000
+	var value2 uint64 = 188427786383
 
 	tests := []struct {
 		desc          string
@@ -856,6 +857,31 @@ func TestGetContainerUsageNanoCores(t *testing.T) {
 			},
 			expected: &value1,
 		},
+		{
+			desc: "should return correct value if elapsed UsageCoreNanoSeconds exceeds 18446744073",
+			stats: &runtimeapi.ContainerStats{
+				Attributes: &runtimeapi.ContainerAttributes{
+					Id: "1",
+				},
+				Cpu: &runtimeapi.CpuUsage{
+					Timestamp: int64(time.Second / time.Nanosecond),
+					UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+						Value: 68172016162105,
+					},
+				},
+			},
+			cpuUsageCache: map[string]*cpuUsageRecord{
+				"1": {
+					stats: &runtimeapi.CpuUsage{
+						Timestamp: 0,
+						UsageCoreNanoSeconds: &runtimeapi.UInt64Value{
+							Value: 67983588375722,
+						},
+					},
+				},
+			},
+			expected: &value2,
+		},
 	}
 
 	for _, test := range tests {

From d32aa6af1d7efae531f0b4d671a827155ad0f436 Mon Sep 17 00:00:00 2001
From: Paul Fisher <pfisher@lyft.com>
Date: Wed, 4 Sep 2019 11:49:15 -0700
Subject: [PATCH 2/2] Add comment for testing 100+ CPU usage

---
 pkg/kubelet/stats/cri_stats_provider_test.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkg/kubelet/stats/cri_stats_provider_test.go b/pkg/kubelet/stats/cri_stats_provider_test.go
index cf7852705a5..18f70ba65bd 100644
--- a/pkg/kubelet/stats/cri_stats_provider_test.go
+++ b/pkg/kubelet/stats/cri_stats_provider_test.go
@@ -757,6 +757,8 @@ func makeFakeLogStats(seed int) *volume.Metrics {
 func TestGetContainerUsageNanoCores(t *testing.T) {
 	var value0 uint64
 	var value1 uint64 = 10000000000
+
+	// Test with a large container of 100+ CPUs
 	var value2 uint64 = 188427786383
 
 	tests := []struct {