About pulsar CPU usage problem

**Describe the bug**
The CPU utilization calculated by process_cpu_seconds_total, pulsar_lb_cpu_usage provided by pulsar and container metrics provided by kubernetes are inconsistent and vary greatly, which is the correct one? Why is there a difference?

**Expressions for calculation of indicators**
```
# process_cpu_seconds_totall
irate(process_cpu_seconds_total{pod="pulsar-private-broker-0"}[5m])

# pulsar_lb_cpu_usagel
pulsar_lb_cpu_usage{pod="pulsar-private-broker-0"}

# Container Metrics Metrics provided by kubernetes
sum(irate(container_cpu_usage_seconds_total{pod="pulsar-private-broker-0"}[5m])) by (pod) / sum(kube_pod_container_resource_limits_cpu_cores{pod="pulsar-private-broker-0"}) by (pod)
```

Start by comparing the definitions and units of process_cpu_seconds_total, pulsar_lb_cpu_usage, and container_cpu_usage_seconds_total in the reported PromQL expressions. Determine why their CPU values differ and document which metric answers each utilization question; no source file or test is identified in the issue.

Written by the indexing model from the issue text.