[PATCH] kexec: Avoid migration of already disabled irqs (ia64)

[magnus.damm at gmail.com (Magnus Damm)]

Hi Nan hai,

On 1/31/07, Zou, Nanhai <nanhai.zou at intel.com> wrote:
> > On 1/31/07, Jay Lan <jlan at sgi.com> wrote:
> > > Magnus Damm wrote:
> > > > kexec: Avoid migration of already disabled irqs (ia64)
> > > >
> > > > This patch fixes up ia64 kexec support for HP rx2620 hardware. It does this
> > > > by skipping migration of already disabled irqs. This is most likely a problem
> > > > on other ia64 platforms as well, but I've only tested this on one machine
> > > > so far.
> > >
> > > I have not seen this problem on SN systems.
> >
> > Ok, thanks. Let me give you more details.
> >
> > When I perform "kexec -e" the following output appears on my serial
> > console (with my patch applied).
>
>  This patch is correct I think. I assume you will also see this bug when trying to offline a CPU by echo 0 > /sys/devices/system/cpu/cpuX/online

You are right, I can trigger the bug that way too.
And the bug goes away with the patch. Excellent!

> However it will not be triggered in crash dump case which has been tested heavily on different kind of platforms. We do not migrate IRQ at the time of crash. I guess that is why Jay has never seen it on SN platforms.

Booting into a crash kernel does not seem to work on this ia64 box
unfortunately. I'm about to investigate why, but I thought trying and
fixing kexec was a good first step.

Thanks for the help!

/ magnus