[Crash-utility] crash-4.0-2.10 ppc64 4-level pagetable fixes

[Dave Anderson]

Badari Pulavarty wrote:

> On Tue, 2005-11-08 at 17:17 -0500, Dave Anderson wrote:
> > Badari Pulavarty wrote:
> >
> > > On Tue, 2005-11-08 at 14:52 -0500, Dave Anderson wrote:
> > > > BTW-- what kernel version introduced this change for ppc64?
> > >
> > > 4-level pagetable went into 2.6.14 for ppc64.
> > > Yuck. That reminds me that "pud_clear_bad()" is not a good
> > > choice for detecting new layout (its a generic routine - not
> > > ppc64 specific and is in 2.6.11 onwards).
> > >
> > > Funny thing is, I am not sure original crash is working
> > > on pre-2.6.14 kernel either. I see PTE_SHIFT changed from
> > > 16 to 17 in 2.6.10. I guess crash is broken from 2.6.10
> > > onwards for ppc64.
> > >
> > > 2.6.10 onwards:
> > > #define PTE_SHIFT (17)
> > >
> > > < 2.6.10: (which crash understands)
> > > #define PTE_SHIFT (16)
> >
> > The PTE_SHIFT change was orthogonal to the intro of 4-level page tables?
> > You would think that they would be tied together, no?
>
> PTE_SHIFT is orthogonal to 4-level changes and it happened in 2.6.10.
> My point is, "crash" wouldn't work for kernels between 2.6.10-2.6.14
> (even with my changes).

Right -- that's what I thought you were implying.  Does that bother
you guys (IBM)?  I'm looking at throught Red-Hat-colored glasses,
presuming that RHEL5 will be based on 2.6.14 or later.  It seems to
be a rather large hole, but I'll let you guys decide on how to best
handle it (or not) .

Dave