Re: [Xen-ia64-devel] Re: [patch] ia64: kexec: add __va_efi

[Simon Horman <horms@xxxxxxxxxxxx>]

On Fri, Mar 14, 2008 at 02:42:55PM -0600, Alex Williamson wrote:
> 
> On Thu, 2008-03-13 at 21:03 -0600, Alex Williamson wrote:
> > On Fri, 2008-03-14 at 10:51 +0900, Simon Horman wrote:
> > > On an HP rx2600 this eliminates the problem where the SAL rendezvous 
> > > address
> > > can't be registered and subsequently the boot fails. I suspect it
> > > solves similar problems that have been seen on other HP machines too.
> > > 
> > > Actually, its rather amazing that the HP rx2620 and Tiger2 that
> > > I have been using work without this fix.
> > 
> >    Wow, that is rather surprising.  Congratulations on tracking this
> > down.  I'll try to verify if this also solves the problem on superdome
> > tomorrow.  Thanks,

Hi Alex,

Thanks, it was certainly a moment of insight when I saw that.

> Hi Simon,
> 
>    Good news/bad news on the superdome.  It was definitely affected by
> the issue you solved on the rx2600 and no longer hangs at boot.
> However, PAL calls are still broken.  It does make it all the way up to
> dom0 userspace before it falls over completely though.  If you have any
> test code I'd be happy to try it, otherwise I'll see if I can find a
> system I can share with you the exhibits the problem.  FWIW, I didn't
> prune down the patch series for this test, I just added this on top of
> the previous 15 patches.  Are you as concerned as I am about how many
> other machine specific issues might still be hidden in this code?
> Thanks,

Patch 13/15 seems nasty, so I think that ought to be left out.
But the other patches that I suggested omitting seem harmless enough.

I am concerned that there might be other areas where __va_efi() needs to
be used and I intend to instrument and inspect that shortly - Friday
end up being meetings all afternoon and believe it or not the keyboard of
my laptop broke, so I wasn't able to do anything more after sending
my previous email.

As for machine specific issues. Yes, I am very concerned about that.
I had it in mind to try and get some good test coverage - somehow.
Some auditing - if someone has the patience and time might help -
it seems that these bugs often turn out to be "well how on earth
was that working at all?" cases, like one.

With regards to the superdome in particular, its good to hear that
there is progress :-) Though not particularly surprising that there
is another hurdle.

Is it worth me going through the logs that you sent last time?
If not, as you probably know I'm not real good with working things
out from logs, but it might be worth sending me some and giving it a
shot.

I think its best to attack these PAL problems, certainly things can't
be healthy while they remain. And they may lead to all manner of
problems that manifest elsewhere in the boot.

-- 
Horms


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