Re: [RFC PATCH 2/4] softirq: Per vector deferment to workqueue

Dmitry Safonov
2018-02-08T20:15:00Z

On Thu, 2018-02-08 at 13:45 -0500, David Miller wrote:
> From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Date: Thu, 8 Feb 2018 18:44:52 +0100
>
> > May I instead suggest to stick to ksoftirqd? So you run in softirq
> > context (after return from IRQ) and if takes too long, you offload
> the
> > vector to ksoftirqd instead. You may want to play with the metric
> on
> > which you decide when you want switch to ksoftirqd / account how
> long a
> > vector runs.
>
> Having read over this stuff for the past few weeks this is how I feel
> as well. Just make ksofbitrq do what we want (only execute the
> overloaded softirq vectors).
>
> The more I look at the workqueue stuff, the more complications and
> weird behavioral artifacts we are getting for questionable gain.

What about creating several ksoftirqd threads per-cpu?
Like I did with boot parameter to specify how many threads and which
softirqs to serve.

--
Thanks,
Dmitry