The CPU.Time is always set to Container StartTime in pod metrics

[AbelHu]

What happened:

kubernetes/pkg/kubelet/stats/cri_stats_provider.go

Lines 467 to 479 in 55412b6

	ps.CPU.Time = cs.StartTime
	usageCoreNanoSeconds := getUint64Value(cs.CPU.UsageCoreNanoSeconds) + getUint64Value(ps.CPU.UsageCoreNanoSeconds)
	usageNanoCores := getUint64Value(cs.CPU.UsageNanoCores) + getUint64Value(ps.CPU.UsageNanoCores)
	ps.CPU.UsageCoreNanoSeconds = &usageCoreNanoSeconds
	ps.CPU.UsageNanoCores = &usageNanoCores
	}
	if cs.Memory != nil {
	if ps.Memory == nil {
	ps.Memory = &statsapi.MemoryStats{}
	}
	ps.Memory.Time = cs.Memory.Time

CPU.Time is set to cs.StartTime but ps.Memory.Time is set to timestamp when collecting the memoryusage.

What you expected to happen:
CPU.Time is set to cs.CPU.Time

How to reproduce it (as minimally and precisely as possible):
Check the code

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):
  master branch when creating this issue.
• Cloud provider or hardware configuration:
• OS (e.g: cat /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Network plugin and version (if this is a network-related bug):
• Others:

[Zheaoli]

/assign

[Zheaoli]

/sig kubelet

[k8s-ci-robot]

@Zheaoli: The label(s) sig/kubelet cannot be applied, because the repository doesn't have them

In response to this:

/sig kubelet

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Zheaoli]

/sig node

[qiutongs]

I am happy to take over this.

/assign