MVME2604 Problems with MMU

[Don Holmgren]

On Fri, 10 Nov 2000, Gabriel Paubert wrote:

>
> On Thu, 9 Nov 2000, fraher wrote:
>
> >
> >    I've got a 2.2.12 kernel with Gabriel's patches (NFS mounted root),
> > and it works beautifully on a MVME2603 board (many thanks, Gabriel).
> > However, when I swap out the MVME2603 with a MVME2604, and cause some
> > SCSI disk activity, the system crashes with
> >
> >         end_scsi_request: buffer-list destroyed
> >         page fault in interrupt handler, addr=8000000
> >         NIP: 08000000 XER: 20000000 LR: C00C67BC REGS: c00ffc48 TRAP: 0400
> >         MSR: 40001032 EE: 0 PR: 0 FP: 0 ME: 1 IR/DR: 11
> >         TASK = c00fdfe8[0] 'swapper' mm->pgd c00fc000 Last syscall: 112
> >                 ...
> >         kernel panic: kernel access of bad area pc 8000000 lr c00c67bc address 8000000 tsk swapper/0
> >
> > The 'page fault' makes me wonder if the 604's TLB miss response differs
> > sufficiently to cause the kernel panic.
> > Has anyone else seen problems running on 2.2.12 with an MVME2604?
> > Are there other patches needed to compensate for the MMU differences
> > with the 604e?
>
> I don't have any MVME2604, but I have several MVME2400 with uptimes in
> the months range. MVME2400 don't have SCSI, but a 750 has processor with
> an MMU very similar to the 604e. Could it be a subtle SCSI/timing problem ?
>
> OTOH, I have reports of working 2604, but I don't remember if it's with
> root on NFS or using SCSI.
>
> 	Gabriel.
>
>

I've been running 2.2.9 successfully on a '2604 with no problems.  Did
specific scsi activities cause the crash, or any just activity at all?

When I get a chance I'll give 2.2.12 a try.

Don Holmgren
Fermilab
djholm at fnal.gov


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