2 ms·
This can be a problem on physical machines too. Ran into an issue where on two identical machines one was showing cpu usage 30% higher. A quick `perf top` sho
by justinsaccount 5y ago
This can be a problem on physical machines too.
Ran into an issue where on two identical machines one was showing cpu usage 30% higher. A quick `perf top` showed it was spending the majority of its time in `read_hpet` in the kernel. Found that one machine was set to hpet because the kernel thought tsc was unstable at bootup:
tsc: Marking TSC unstable due to check_tsc_sync_source failed
Only ever happened one time and we could never reproduce it. bios/firmware updates might have also helped. We still added a monitoring check to ensure that current_clocksource was tsc.