Re: Latest tip kernel(3.2-rc1-tip_cf6b3899) fails to boot on x3850x5 machine

From: Yinghai Lu
Date: Fri Dec 16 2011 - 13:03:49 EST


On Fri, Dec 16, 2011 at 12:40 AM, Ingo Molnar <mingo@xxxxxxx> wrote:

> IRQ_REMAP is a 'complex' option:
>
> config IRQ_REMAP
>        bool "Support for Interrupt Remapping (EXPERIMENTAL)"
>        depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
>        select DMAR_TABLE
>
> and selecting such complex options is generally dangerous, as
> the sub-dependencies are not explicitly selected. So if say
> PCI_MSI or ACPI are disabled, the select will still be performed
> by X86_X2APIC.
>
> Can we make the IRQ_REMAP default depend on X86_X2APIC or so, to
> solve this problem?

but user could use IRQ_REMAP without x2apic.

We could have

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -286,7 +286,8 @@ config SMP

config X86_X2APIC
bool "Support x2apic"
- depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
+ depends on X86_LOCAL_APIC && X86_64 && X86_IO_APIC && PCI_MSI && ACPI
+ select IRQ_REMAP
---help---
This enables x2apic support on CPUs that have this feature.

BTW:
Suresh, can we remove EXPERIMENTAL for IRQ_REMAP now?

Thanks

Yinghai
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