Re: [PATCH] add netconsole support for xen-netfront

From: Konrad Rzeszutek Wilk
Date: Mon Jan 23 2012 - 13:27:11 EST


On Wed, Jan 18, 2012 at 01:06:47PM -0800, Tina Yang wrote:
> On 1/18/2012 12:59 AM, Ian Campbell wrote:
> >On Tue, 2012-01-17 at 23:15 +0000, Tina Yang wrote:
> >>On 1/17/2012 1:51 PM, Konrad Rzeszutek Wilk wrote:
> >>>On Tue, Jan 17, 2012 at 01:42:22PM -0800, Tina Yang wrote:
> >>>>On 1/13/2012 3:06 AM, Ian Campbell wrote:
> >>>>Although netdump is now obsolete, I think it's always a good practice
> >>>>to preserve caller's irq status as we had a very bad experience
> >>>>chasing a similar problem caused by such a irq change in RDS
> >>>Did you find the culprit of it? Was there a patch for that in the
> >>>upstream kernel?
> >>Yes. It has nothing to do with net drivers but same cause
> >>elsewhere in the kernel.
> >I didn't think start_xmit could be called with interrupts disabled or
> >from interrupt context but perhaps I am wrong about that or perhaps
> >netconsole changes things?
> Netdump does call it with interrupt disabled and hang because of
> it in 2.6.9 as I remember it. And you are right, netconsole has
> undergone changes from time to time, which also can change
> this specification.
> >
> >Right, Documentation/networking/netdevices.txt states that start_xmit
> >can be called with interrupts disabled by netconsole and therefore using
> >the irqsave/restore locking in this function is, AFAICT, correct.

Ok, so let me update the git commit description to include this.

I am listed as the maintainer but I would have thought that it should
go through David?

David, should it go through you or should I stick it in my tree? Here
is the patch with a better git description.