Re: ddb(4) and LOCKDEBUG incompatibility

[Matt Thomas <matt%3am-software.com@localhost>]

On May 30, 2008, at 3:42 AM, Andrew Doran wrote:

> 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.

That than changing all the ports (powerpc has done that check since  
'03),
now that we have cpu_intr_p(), make uvm_fault check it.