Re: [Patch v3 2/2] x86/acpi: Remove the repeated lapic address override entry parsing

From: Ingo Molnar
Date: Thu Aug 11 2016 - 04:37:58 EST



* Baoquan He <bhe@xxxxxxxxxx> wrote:

> On 08/10/16 at 04:02pm, Ingo Molnar wrote:
> >
> > * Baoquan He <bhe@xxxxxxxxxx> wrote:
> >
> > > ACPI MADT has a 32-bit field providing lapic address at which
> > > each processor can access its lapic information. MADT also contains
> > > an optional entry to provide a 64-bit address to override the 32-bit
> > > one. However the current code does the lapic address override entry
> > > parsing twice. One is in early_acpi_boot_init() because AMD NUMA need
> > > get boot_cpu_id earlier. The other is in acpi_boot_init() which parses
> > > all MADT entries.
> > >
> > > So in this patch remove the repeated code in the 2nd part. Meanwhile
> > > print lapic override entry information like other MADT entry, this
> > > will be added to boot log.
> >
> > it is not at all clear to me from this changelog whether the change is supposed to
> > change anything. If not then please spell it out explicitly:
> >
> > "This patch is not supposed to change any behavior."
>
> I don't know if adding new information to boot log can be seen as
> behavior change. If lapic override entry exist, the code change will
> add one line of message to boot log:
>
> LAPIC_ADDR_OVR (address[0xXXXXXXXX])
>
> If this is not behavior change, I will add the sentence you suggested.

Yeah, you can write it:

"This patch is not supposed to change any runtime behavior, other than
improving kernel messages."

Thanks,

Ingo