virtio balloon: do not call blocking ops when !TASK_RUNNING

Thomas Huth
2015-02-26T07:36:25Z

On Thu, 26 Feb 2015 11:50:42 +1030
Rusty Russell <rusty at rustcorp.com.au> wrote:

> Thomas Huth <thuth at linux.vnet.ibm.com> writes:
> >  Hi all,
> >
> > with the recent kernel 3.19, I get a kernel warning when I start my
> > KVM guest on s390 with virtio balloon enabled:
>
> The deeper problem is that virtio_ccw_get_config just silently fails on
> OOM.
>
> Neither get_config nor set_config are expected to fail.

AFAIK this is currently not a problem. According to
http://lwn.net/Articles/627419/ these kmalloc calls never
fail because they allocate less than a page.

 Thomas