Re: [PATCH v8 06/13] x86/apic: Mark the apic_intr_mode extern for sanity check cleanup

[Dou Liyang]

Hi Baoquan,

At 09/06/2017 01:26 PM, Baoquan He wrote:
[...]
> > >  static void __init smp_cpu_index_default(void)
> > > @@ -1335,19 +1295,20 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
> >
> > Please also cleanup the passed in max_cpus since it's not used here any
> > more. And up to the caller:
>
> Oops, I just checked x86 code, other arch also have this hook. Please
> ingore this comment.

Yes, you are right.

As I also found the comments for native_smp_prepare_cpus() is out of
date. I will update the comment and explain it like:

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 4f63afc..9f8479c 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1260,8 +1260,10 @@ static void __init smp_get_logical_apicid(void)
 }

 /*
- * Prepare for SMP bootup.  The MP table or ACPI has been read
- * earlier.  Just do some sanity checking here and enable APIC mode.
+ * Prepare for SMP bootup.
+ *
+ * @max_cpus: configured maximum number of CPUs
+ * It don't be used, but other arch also have this hook, so keep it.
  */
 void __init native_smp_prepare_cpus(unsigned int max_cpus)
 {

Thanks,
	dou.
> > static noinline void __init kernel_init_freeable(void)
> > {
> > 	...
> > 	smp_prepare_cpus(setup_max_cpus);
> > 	...
> > }
> >
> > >  	apic_intr_mode_init();
> > >
> > > -	switch (smp_sanity_check(max_cpus)) {
> > > -	case SMP_NO_CONFIG:
> > > -		disable_smp();
> > > -		return;
> > > -	case SMP_NO_APIC:
> > > +	smp_sanity_check();
> > > +
> > > +	switch (apic_intr_mode) {
> > > +	case APIC_PIC:
> > > +	case APIC_VIRTUAL_WIRE_NO_CONFIG:
> > >  		disable_smp();
> > >  		return;
> > > -	case SMP_FORCE_UP:
> > > +	case APIC_SYMMETRIC_IO_NO_ROUTING:
> > >  		disable_smp();
> > >  		/* Setup local timer */
> > >  		x86_init.timers.setup_percpu_clockev();
> > >  		return;
> > > -	case SMP_OK:
> > > +	case APIC_VIRTUAL_WIRE:
> > > +	case APIC_SYMMETRIC_IO:
> > >  		break;
> > >  	}
> > >
> > > --
> > > 2.5.5