Re: [PATCH 3/3] x86/irq: update first_system_vector only when X86_LOCAL_PIC is on

From: Thomas Gleixner
Date: Sun Mar 13 2016 - 07:14:29 EST

On Sun, 13 Mar 2016, Jianyu Zhan wrote:
> On Sun, Mar 13, 2016 at 5:33 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > IRQ_WORK can work w/o APIC
> >
> > Emphasis on CAN. If the APIC is available it's used, if not then there is no
> > point in setting up the gate for nothing.
> >
> > So why would your patch do any good?
> I understood it is no point setting up if APIC is not available, but
> just got confused by
> your wording 'can', now all clear.
> As for the patch set. My initial purpose is just wanting to make the
> layout clear and
> clean up stale comments and dead code:
> #define first_system_vector NR_VECTORS
> #endif
> as we've talked about this before, it won't ever be change on
> so no point define it here(it is initialized to NR_VECTORS).

Hell no. If CONFIG_X86_LOCAL_APIC=n then first_system_vector is not a variable
and not available and not initialized at all.

> Since all points are clear now,

Obviously not.