Re: ddb(4) and LOCKDEBUG incompatibility

[Andrew Doran <ad%netbsd.org@localhost>]

On Thu, May 29, 2008 at 11:23:42PM -0500, David Young wrote:

> I hit the magic keys on a NetBSD router to break into ddb, and I got
> the LOCKDEBUG panic and page fault loop (see below).  I'm wondering if
> there is a prayer of using ddb and LOCKDEBUG together, since it can be
> awfully useful.
> 
> It seems that we can sometimes punt on synchronization when ddb is active,
> since that implies that the other CPUs on the system are suspended.
> Thoughts?

There's no way we can resolve page faults from interrupt context, so I have
changed x86 to not call uvm_fault() if an interrupt is active. I think that
should fix it.

Thanks,
Andrew