Re: [PATCH] x86/jailhouse: fix building without X86_X2APIC

[Dou Liyang]

Hi Arnd,

At 01/16/2018 04:50 PM, Arnd Bergmann wrote:
> On Tue, Jan 16, 2018 at 9:17 AM, Dou Liyang <douly.fnst@xxxxxxxxxxxxxx> wrote:
> > Hi Arnd,
> >
> > [...]
> > > > The reason I don't want to expose the x2apic_mode and x2apic_phys is
> > > > that they may be misused in X2APIC=n case. So I create an interface to
> > > > wrap it. do you think so? ;-)
> > >
> > >
> > > I'm not sure I follow what the intention of that is. If you want to hide
> >
> >
> > My purpose of that is hiding the variables in X2APIC=n case.
>
> But why? I'd say either hide them all the time, or don't hide them at all.

In this case, I prefer to hide them all the time.

> > > I see nothing wrong it with this, but also don't see anything it does
> > > that improves the interface.
> >
> > Another way we can choice is wrap the code with "CONFIG_X86_X2APIC".
>
> But why? That just makes perfectly reasonably code uglier. Generally
> speaking, compiler conditionals are better than preprocessor conditionals
> for this, as they are easier to read and provide better compile-time coverage
> when things go wrong, such as the missing declaration.

Yes, Indeed. Thank you for telling me that.

Thanks,
	dou.