Re: [PATCH 1/4] softirq: implement IRQ flood detection mechanism

[Bart Van Assche]

On 9/4/19 10:31 AM, Daniel Lezcano wrote:
> On 04/09/2019 19:07, Bart Van Assche wrote:
> > Only if CONFIG_IRQ_TIME_ACCOUNTING has been enabled. However, I don't
> > know any Linux distro that enables that option. That's probably because
> > that option introduces two rdtsc() calls in each interrupt. Given the
> > overhead introduced by this option, I don't think this is the solution
> > Ming is looking for.
>
> Was this overhead reported somewhere ?
 I think it is widely known that rdtsc is a relatively slow x86 
instruction. So I expect that using that instruction will cause a 
measurable overhead if it is called frequently enough. I'm not aware of 
any publicly available measurement data however.

Bart.