Re: [PATCH 4/5] x86, acpi, cpu-hotplug: Enable MADT APIs to return disabled apicid.

Tejun Heo
2015-07-15T22:06:30Z

Hello,

On Tue, Jul 07, 2015 at 05:30:24PM +0800, Tang Chen wrote:
> From: Gu Zheng <guz.fnst@cn.fujitsu.com>
>
> All processors' apicids can be obtained by _MAT method or from MADT in ACPI.
> The current code ignores disabled processors and returns -ENODEV.
>
> After this patch, a new parameter will be added to MADT APIs so that caller
> is able to control if disabled processors are ignored.

This describes what the patch does but doesn't really explain what the
patch is trying to achieve.

> @@ -282,8 +282,11 @@ static int acpi_processor_get_info(struct acpi_device *device)
> * Extra Processor objects may be enumerated on MP systems with
> * less than the max # of CPUs. They should be ignored _iff
> * they are physically not present.
> + *
> + * NOTE: Even if the processor has a cpuid, it may not present because
^
be
> + * cpuid <-> apicid mapping is persistent now.

Saying "now" is kinda weird as this is how the code is gonna be
forever.

Thanks.

--
tejun