* tip-bot for HATAYAMA Daisuke <tip...@zytor.com> wrote:
> /*
> + * Processor to be disabled specified by kernel parameter
> + * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
> + * avoid undefined behaviour caused by sending INIT from AP to BSP.
> + */
> +unsigned int disabled_cpu_apicid = BAD_APICID;
Any reason why this isn't static & read_mostly?
> @@ -2114,6 +2121,39 @@ int generic_processor_info(int apicid, int version)
> phys_cpu_present_map);
>
> /*
> + * boot_cpu_physical_apicid is designed to have the apicid
> + * returned by read_apic_id(), i.e, the apicid of the
> + * currently booting-up processor. However, on some platforms,
> + * it is temporarilly modified by the apicid reported as BSP
s/temporarily
> + * through MP table. Concretely:
> + *
> + * - arch/x86/kernel/mpparse.c: MP_processor_info()
> + * - arch/x86/mm/amdtopology.c: amd_numa_init()
> + * - arch/x86/platform/visws/visws_quirks.c: MP_processor_info()
> + *
> + * This function is executed with the modified
> + * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
> + * parameter doesn't work to disable APs on kdump 2nd kernel.
> + *
> + * Since fixing handling of boot_cpu_physical_apicid requires
> + * another discussion and tests on each platform, we leave it
> + * for now and here we use read_apic_id() directly in this
> + * function, generic_processor_info().
> + */
> + if (disabled_cpu_apicid != BAD_APICID &&
> + disabled_cpu_apicid != read_apic_id() &&
> + disabled_cpu_apicid == apicid) {
> + int thiscpu = num_processors + disabled_cpus;
> +
> + pr_warning("ACPI: Disabling requested cpu."
> + " Processor %d/0x%x ignored.\n",
> + thiscpu, apicid);
Why does this message say 'ACPI'? Shouldn't it say 'apic' instead?
Thanks,
Ingo
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