Crashes with the current -HEAD

[C. Jayachandran]

On Tue, Apr 27, 2010 at 1:19 AM, Juli Mallett <jmallett at freebsd.org> wrote:
> On Mon, Apr 26, 2010 at 12:36, C. Jayachandran <c.jayachandran at gmail.com> wrote:
>> I checked a few versions,  r206714 does not have the crash, r206717
>> has. I haven't looked at the changes yet, but if you have any
>> suggestions let me know.
>
> There are two things there that could be problematic.
>
> The first is that interrupt enable/disable has been changed.  I don't
> know anything about hazards on RMI systems, but if there's an
> interrupt disable hazard, you may want to change CLEAR_STATUS and
> DO_AST macros (in exception.S and asm.h respectively) to use many more
> nops or ehbs and see if that makes the problem go away.

XLR does not need any hazards for this.

> The second is the changes to the lmem pages.  If you reduce MAXMEM so
> that all of your memory is addressable within KSEG0 and KSEG1, you
> won't use lmem at all.  If that makes the problem go away, it suggests
> there is trouble in that area.
>
> I'm glad to do whatever I can, but I've been unable to get any RMI
> hardware, so all I can do is suggest you look at those two areas your
> try to narrow down to the specific change that caused the problem.


>From the crash it looks like the  PTE/PDE entires of some user
processes are getting corrupted. May be this is due to the LMEM
changes - will look at the code....

Regards,
JC.