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

[Ingo Molnar]

* Dean Nelson <dcn@xxxxxxx> wrote:

> On Mon, Aug 11, 2008 at 12:39:22PM -0700, Eric W. Biederman wrote:
> >
> > Although I am not at all convinced that dynamic allocation of
> > the vector number (instead of statically reserving it makes sense).
> 
> 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()). 

while i understand the UV_BAU_MESSAGE case (TLB flushes are special), 
why does sgi-gru and sgi-xp need to go that deep? They are drivers, they 
should be able to make use of an ordinary irq just like the other 2000 
drivers we have do.

> 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.

which debugger is this?

	Ingo
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