Re: [RFC 8/8] x86_64: Support for new UV apic

From: Glauber Costa
Date: Tue Mar 25 2008 - 23:24:19 EST


On Tue, Mar 25, 2008 at 1:31 PM, Jack Steiner <steiner@xxxxxxx> wrote:
> On Tue, Mar 25, 2008 at 03:30:59PM +0100, Ingo Molnar wrote:
> >
> > * Jack Steiner <steiner@xxxxxxx> wrote:
> >
> > > Index: linux/arch/x86/kernel/genapic_64.c
> >
> > > @@ -69,7 +73,16 @@ void send_IPI_self(int vector)
> > >
> > > unsigned int get_apic_id(void)
> > > {
> > > - return (apic_read(APIC_ID) >> 24) & 0xFFu;
> > > + unsigned int id;
> > > +
> > > + preempt_disable();
> > > + id = apic_read(APIC_ID);
> > > + if (uv_system_type >= UV_X2APIC)
> > > + id |= __get_cpu_var(x2apic_extra_bits);
> > > + else
> > > + id = (id >> 24) & 0xFFu;;
> > > + preempt_enable();
> > > + return id;
> >
> > dont we want to put get_apic_id() into struct genapic instead? We
> > already have ID management there.
> >
> > also, we want to unify 32-bit and 64-bit genapic code and just have
> > genapic all across x86.
>
> Long term, I think that makes sense. However, I think that should be a
> separate series of patches since there are significant differences between
> the 32-bit and 64-bit genapic structs.
>
However, if you add more code, they'll keep diverging. The moment you
touch them, and get your
hands warmed up, is the perfect moment for an integration series.

--
Glauber Costa.
"Free as in Freedom"
http://glommer.net

"The less confident you are, the more serious you have to act."
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