Re: BUG: 'list_empty(&vgdev->free_vbufs)' is true!

From: Gerd Hoffmann
Date: Wed Nov 16 2016 - 08:13:01 EST


On Fr, 2016-11-11 at 17:28 +0100, Jiri Slaby wrote:
> On 11/09/2016, 09:01 AM, Gerd Hoffmann wrote:
> > On Di, 2016-11-08 at 22:37 +0200, Michael S. Tsirkin wrote:
> >> On Mon, Nov 07, 2016 at 09:43:24AM +0100, Jiri Slaby wrote:
> >>> Hi,
> >>>
> >>> I can relatively easily reproduce this bug:
> >
> > How?
>
> Run dmesg -w in the qemu window (virtio_gpu) to see a lot of output.
> Run pps [1] without exit(0); on e.g. serial console.
> Wait a bit. The lot of output causes the BUG.
>
> [1] https://github.com/jirislaby/collected_sources/blob/master/pps.c

Doesn't reproduce here.

Running "while true; do dmesg; done" on the virtio-gpu fbcon.
Running the pps fork bomb on the serial console.

Can watch dmesg printing the kernel messages over and over, until the
shell can't spawn dmesg any more due to the fork bomb hitting the
process limit. No BUG() triggered.

Tried spice, gtk and sdl.

Hmm.

Any ideas what else might be needed to reproduce it?

cheers,
Gerd