Description of problem:

The node_exporter sometimes uses high cpu under load and it looks like a spinlock race on multiple CPUs.

Version-Release number of selected component (if applicable):

4.8.23, large number of CPUs host like 96 CPUs

How reproducible:

Always in customer env

Steps to Reproduce:
1. Generate load and monitor node resources using top command with 10 sec interval
2.
3.

Actual results:

node_exporter sometimes use N * 100% CPU for a while. Normally it uses only 5%.

Expected results:

No unexpected high CPU usage with node_exporter

Additional info:

Similar spinlock race high CPU usage is reported in upstream when cpufreq collector is enabled. It sounds like the spinlock race happens without the cpufreq where the node_exporter cannot get metrics smoothly for some reason.

https://github.com/prometheus/node_exporter/issues/1963
https://github.com/prometheus/node_exporter/pull/1964
https://github.com/prometheus/node_exporter/issues/1880