hi,

> The queue is shared for all non-urgent pmap updates (e.g. thoses that can wait
> until the next context switch). I know it's not empty, because of the panic
> I'm seeing. I could try to see if there are updates pending for this
> PA, but this would mean making the queue updates interrupt-safe, which I'm
> trying to avoid ...

which panic are you seeing?

xpq_queue_* routines need to be interrupt safe anyway.

YAMAMOTO Takashi