[powerpc] Next tree Nov 2 : kernel BUG at mm/mmap.c:2135!

[David Gibson]

On Thu, Nov 12, 2009 at 04:46:40PM +0530, Sachin Sant wrote:
> David Gibson wrote:
> >On Wed, Nov 04, 2009 at 06:08:44PM +0530, Sachin Sant wrote:
> >>Sachin Sant wrote:
> >>>Today's next tree failed to boot on a POWER 6 box with :
> >>>
> >>>------------[ cut here ]------------
> >>>kernel BUG at mm/mmap.c:2135!
> >>>Oops: Exception in kernel mode, sig: 5 [#2]
> >>>SMP NR_CPUS=1024 NUMA pSeries
> >>Problem exists with today's next as well.
> >>
> >>Likely cause for this problem seems to the following commit.
> >>If i revert this patch the machine boots fine.
> >>
> >>commit a0668cdc154e54bf0c85182e0535eea237d53146
> >>powerpc/mm: Cleanup management of kmem_caches for pagetables
> >
> >Ugh.  Ok, it's not at all obvious how my patch could cause this bug.
> >Can you send your .config?
> >
> Still present in today's next.

Sorry, I've been sidetracked by other issues and have only managed to
look into this today.  My initial attempts to reproduce the bug with
your config on both POWER6 and POWER5+ have failed though.

Is it possible to get the complete boot log from this system - not
just the [cut here] section around the BUG()?  This should help to
determine exactly when during boot the bug is being triggered.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson