Re: [RFC PATCH 0/2] net: threadable napi poll loop

From: Eric Dumazet
Date: Tue May 10 2016 - 17:09:47 EST


On Tue, May 10, 2016 at 1:46 PM, Hannes Frederic Sowa
<hannes@xxxxxxxxxxxxxxxxxxx> wrote:

> I agree here, but I don't think this patch particularly is a lot of
> bloat and something very interesting people can play with and extend upon.
>

Sure, very rarely patch authors think their stuff is bloat.

I prefer to fix kernel softirq.c, or at least show me that you tried
hard enough.

I am pretty sure that the following would work :

When ksoftirqd is scheduled, remember this in a per cpu variable
(ksoftiqd_scheduled)

When enabling BH , do not call do_softirq() if this variable is set.

ksoftirqd would clear the variable at the right place (probably in
run_ksoftirqd())

Sure, this might add a lot of latency regressions, but lets fix them.