Re: [RFC 0/4] dynamically allocate arch specific system vectors

Dean Nelson
2008-09-12T11:46:51Z

On Thu, Sep 11, 2008 at 01:04:35PM -0700, H. Peter Anvin wrote:
> Dean Nelson wrote:
> >
> >We (SGI) need somewhere around eight vectors.
> >
> >There are two kernel modules, sgi-gru and sgi-xp (in drivers/misc), that
> >each need two vectors. And there's the broadcast assist unit (BAU) that is
> >involved in tlb shootdown on uv, which currently uses statically reserved
> >vector 0xf8 (UV_BAU_MESSAGE -- see uv_bau_init()). I know of a debugger
> >that
> >also uses 0xf8 because it was previously available until UV_BAU_MESSAGE
> >came
> >along. The BAU would be happy with a dynamically allocated system vector.
> >We have a couple of other things in the works that also need vectors.
> >
> >All of these eight or so vectors are only meaningful on SGI uv systems.
> >
>
> Are these kernel-internal vectors, or exposed to userspace (i.e. the INT
> instruction works in userspace)? From what I'm gathering, I think this
> is the former.

Yeah, these are kernel-internal vectors and are not exposed to userspace.