Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch 37/53] x86/cpu: Detect real BSP on crash kernels | Date | Mon, 08 Jan 2024 17:13:31 +0100 |
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On Mon, Jan 08 2024 at 15:54, Thomas Gleixner wrote:
> On Mon, Jan 08 2024 at 14:11, Zhang, Rui wrote: >>> +static __init void check_for_kdump_kernel(void) >>> +{ >>> + u32 bsp_apicid; >>> + >>> + /* >>> + * There is no real good way to detect whether this a kdump() >>> + * kernel, but except on the Voyager SMP monstrosity which is >>> not >>> + * longer supported, the real BSP has always the lowest >>> numbered >>> + * APIC ID. If a crash happened on an AP, which then ends up >>> as >>> + * boot CPU in the kdump() kernel, then sending INIT to the >>> real >>> + * BSP would reset the whole system. >>> + */ >> >> >> Hi, Thomas, >> >> Unfortunately this causes a regression on Intel Meteorlake platform, >> where the BSP APIC ID is NOT the lowest numbered APIC ID (instead, >> CPU12, the first Ecore CPU, has APIC ID 0). > > Bah. Let me think about that.
In which order are the APICs/CPUs enumerated by ACPI?
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