Re: [PATCH 1/2] net: Assert proper context while calling napi_schedule()

Breno Leitao
2025-02-14T13:05:22Z

On Thu, Feb 13, 2025 at 11:04:52AM -0800, Jakub Kicinski wrote:
> On Thu, 13 Feb 2025 10:14:02 -0800 Breno Leitao wrote:
> > > The problem is a bit nasty, on a closer look. We don't know if netcons
> > > is called in IRQ context or not. How about we add an hrtimer to netdevsim,
> > > schedule it to fire 5usec in the future instead of scheduling NAPI
> > > immediately? We can call napi_schedule() from a timer safely.
> > >
> > > Unless there's another driver which schedules NAPI from xmit.
> > > Then we'd need to try harder to fix this in netpoll.
> > > veth does use NAPI on xmit but it sets IFF_DISABLE_NETPOLL already.
> >
> > Just to make sure I follow the netpoll issue. What would you like to fix
> > in netpoll exactly?
>
> Nothing in netpoll, the problem is that netdevsim calls napi_schedule

Hm, you said the following above:

Then we'd need to try harder to fix this in netpoll.

I was curious about the meaning of that statement?

Thanks
--breno