* Eric Dumazet <eduma...@google.com> wrote:
> I noticed high latencies caused by a daemon periodically reading
> various MSR on all cpus. KASAN kernels would see ~10ms latencies
> simply reading one MSR. Even without KASAN, sending IPI to CPU
> in deep sleep state or blocking hard IRQ in a a long section,
> then waiting for the answer can consume hundreds of usec.
>
> Converts rdmsr_safe_on_cpu() to use a completion instead
> of busy polling.
>
> Overall daemon cpu usage was reduced by 35 %,
> and latencies caused by msr_read() disappeared.
What "daemon" is this and why is it reading MSRs?
Thanks,
Ingo
