Subject: Re: -current TLB panics on 3100?
To: Toru Nishimura <nisimura@itc.aist-nara.ac.jp>
From: Michael L. Hitch <mhitch@lightning.msu.montana.edu>
List: port-pmax
Date: 11/09/1999 13:51:52
On Tue, 9 Nov 1999, Toru Nishimura wrote:

> >        Actually, it was just MIPS1.  When I uncommented MIPS3 and rebuilt
> > the kernel I was able to do several 'make install's in /usr/src without the
> > machine panicking even once.  Seems to be working great!
> 
> Aiyah.  I must have broken MIPS1-only configuration.  Earlier this year
> I made changes in TLB handling which takes effects MIPS1-only kernel.
> I got another panic report about MIPS1 TLB miss, so this issue
> definitely needs to be solved before 1.5.   It's strange since my
> MIPS1-only kernel made no TLB miss for long time since then.

  I can't think of how a MIPS1-only system might be causing the pm_segtab
entry to be NULL, since the segment table & segment map stuff should be
independent of MIPS1 and/or MIPS3.

> Is anyone out there experiencing a similar trouble w/ MIPS1-only kernel
> these days?

  I have just 'successfully' reproduced this, and it's easily reproduced
on my system (in fact, it's almost completely unusable!).

  I just built my custom kernel for a 5000/200 I've been running, and it
gets the TLB bug 'reliably' during boot up.  I am in the process right
now of trying to get a core dump of the system so I can do some
post-mortem kernel groveling.  I've also added some additional debugging
output in the UTLBmod handler.  Hopefully this shouldn't take too long
to track down now.

Michael
--
Michael L. Hitch			mhitch@montana.edu
Computer Consultant
Information Technology Center
Montana State University	Bozeman, MT	USA