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Re: ddb(4) and LOCKDEBUG incompatibility

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.

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.

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