Re: 2.6.15-mm4 failure on power5

Michael Ellerman
2006-01-18T00:19:57Z

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On Wed, 18 Jan 2006 01:00, Ingo Molnar wrote:
> * Michael Ellerman <michael@ellerman.id.au> wrote:
> > On Tue, 17 Jan 2006 08:52, Dave C Boutcher wrote:
> > > 2.6.15-mm4 won't boot on my power5 either. I tracked it down to the
> > > following mutex patch from Ingo: kernel-kernel-cpuc-to-mutexes.patch
> > >
> > > If I revert just that patch, mm4 boots fine. Its really not obvious to
> > > me at all why that patch is breaking things though...
> >
> > My POWER5 (gr) LPAR seems to boot ok (3 times so far) with that patch,
> > guess it's something subtle. That's with CONFIG_DEBUG_MUTEXES=y. And
> > it's just booted once with CONFIG_DEBUG_MUTEXES=n.
> >
> > And now it's booted the full mm4 patch set without blinking.
>
> so it booted fine with CONFIG_DEBUG_MUTEXES=n but with that patch not
> applied?
>
> the patch will likely work around the bug, so DEBUG_MUTEXES=y/n should
> make no difference with that patch applied.

It booted fine _with_ the patch applied, with DEBUG_MUTEXES=y and n.

Boutcher, to be clear, you can't boot with kernel-kernel-cpuc-to-mutexes.patch
applied and DEBUG_MUTEXES=y ?

But if you revert kernel-kernel-cpuc-to-mutexes.patch it boots ok?

This is looking quite similar to another hang we're seeing on Power4 iSeries
on mainline git:
http://ozlabs.org/pipermail/linuxppc64-dev/2006-January/007679.html

cheers

--
Michael Ellerman
IBM OzLabs

email: michael:ellerman.id.au
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wwweb: http://michael.ellerman.id.au
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We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person

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