This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] RE: [PATCH v2 2/2] x86: don't unmask disabled irqs when migr

On Fri, 6 May 2011, Tian, Kevin wrote:
> > From: Thomas Gleixner
> > Sent: Friday, May 06, 2011 6:00 PM
> > 
> > On Fri, 6 May 2011, Tian, Kevin wrote:
> > > x86: don't unmask disabled irqs when migrating them
> > >
> > > it doesn't make sense to mask/unmask a disabled irq when migrating it
> > > from offlined cpu to another, because it's not expected to handle any
> > > instance of it. Current mask/set_affinity/unmask steps may trigger
> > > unexpected instance on disabled irq which then simply bug on when
> > > there is no handler for it. One failing example is observed in Xen.
> > > Xen pvops
> > 
> > So there is no handler, why the heck is there an irq action?
> > 
> >       if (!irq_has_action(irq) ....
> >             continue;
> > 
> > Should have caught an uninitialized interrupt. If Xen abuses interrupts 
> > that way,
> > then it rightfully explodes. And we do not fix it by magic somewhere else.
> sorry that my bad description here. there does be a dummy handler registered
> on such irqs which simply throws out a BUG_ON when hit. I should just say 
> such 
> injection is not expected instead of no handler. :-)

I don't think this patch is necessary anymore after the event channel
handling cleanup patches I have just sent to the list.
Could you please try the following two patches:


and let me know if you still need this patch?

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>