[PATCH 7/7] um: simplify IRQ handling code

[Johannes Berg]

On Wed, 2020-12-02 at 09:03 +0000, Anton Ivanov wrote:
> 
> raw sockets on a vEth pair.
> 
> I avoid tap as it does not exercise the full vector IO code for now.
> One day I will find a way to extract from the kernel the underlying
> socket which tap uses internally and it will become 100% equivalent to
> the other transports.

OK, thanks.

> > > Try to ifup/ifdown the vecX interface inside the UML.
> > > 
> > > With master it works fine. With this patch it fails.
> > How does it fail?
> 
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 401 at arch/um/kernel/irq.c:177 um_request_irq+0xff/0x22e

Hm, interesting. So that means the IRQ was still busy after
vector_net_close()?

I'm still digging and trying to build a test case, but if you have a
test case at hand .. I wonder if IRQ aliasing happened - if you remove
the "goto out;" in free_irq_by_irq_and_dev(), does that help?


johannes