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

Eric W. Biederman
2008-09-17T19:05:46Z

Dimitri Sivanich <sivanich@sgi.com> writes:

> On Tue, Sep 16, 2008 at 03:46:54PM -0500, Dean Nelson wrote:
>> On Tue, Sep 16, 2008 at 10:24:48AM +0200, Ingo Molnar wrote:
>> >
>> > * Dean Nelson <dcn@sgi.com> wrote:
>> >
>> > > > 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.
>> > >
>> > > The sgi-gru driver needs to be able to allocate a single irq/vector
>> > > pair for all CPUs even those that are not currently online. The sgi-xp
>> > > driver has similar but not as stringent needs.

I need to look at these patches some more (apologies I got busy).

We can not assign a vector to all CPUS.

We don't have the fields for vector -> irq mapping for cpus that
are not-online. So we can only assign to cpus that are online now.
And latter add the other cpus when they come online.

I have had that oops, it sucks, I don't want to go back.

Eric