Re: [RFC 1/2] softirq: Defer net rx/tx processing to ksoftirqd context

[Linus Torvalds]

On Thu, Jan 11, 2018 at 12:34 PM, Dmitry Safonov <dima@xxxxxxxxxx> wrote:
>
> I could try to write a PoC for that..
> What should be the trigger to fall into workqueue?
> How to tell if there're too many softirqs of the kind?

I suspect it would have to be time-based, probably using the scheduler clock.

Most softirqs are really really small. So just counting them probably
isn't all that meaningful, although the count is good as a fallback
(as shown by the jiffy issues).

The good news is that we only have a fairly small handful of softirqs,
so counting/timing them separately is still mainly a pretty small
array (which needs to be percpu, of course).

                 Linus