Re: Re: CONFIG_SPARSE_IRQ breaks single VCPU domain 0 between xen/master and xen/next

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Mar 01, 2010 at 10:33:17AM +0000, Ian Campbell wrote:
> On Sun, 2010-02-28 at 12:01 +0000, Erik Brakkee wrote:
> > Ian Campbell <Ian.Campbell <at> citrix.com> writes:
> > 
> > > 
> > > With a single VCPU domain 0 (either due to hardware on dom0_max_vcpus=1)
> > > and CONFIG_SPARSE_IRQ on xen/next I see:
> > > 
> > >         Kernel panic - not syncing: No available IRQ to bind to: increase
> > nr_irqs! (currently 256, started from 256)
> > > 
> > 
> > 
> > The strange thing is that the kernel panic at boot also appears with xen/master
> > now. I am using the .config from
> > http://wiki.xensource.com/xenwiki/XenParavirtOps. This behavior is occurring on
> > a Sony Vaio F11 laptop (Core i7 720QM, 8GB memory).
> > 
> > Is there a simple workaround for this problem?
> 
> I think the xen/master case is actually down to my "fix off-by-one error
> in find_unbound_irq" change -- should probably be reverted.

Shouldn't your other patch, the one that inserts the

if (start == nr_irqs) goto out;

be added instead?