Messages in this thread | | | Date | Tue, 20 Oct 2020 13:32:03 +0100 | From | Marc Zyngier <> | Subject | Re: [PATCH v5 1/5] arm64: Add framework to turn IPI as NMI |
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On 2020-10-20 13:25, Daniel Thompson wrote: > On Tue, Oct 20, 2020 at 04:52:43PM +0530, Sumit Garg wrote:
[...]
>> So in general, IPI as a normal IRQ is still useful for debugging but >> it can't debug a core which is stuck in deadlock with interrupts >> disabled. >> >> And since we choose override default implementations for pseudo NMI >> support, we need to be backwards compatible for platforms which don't >> possess pseudo NMI support. > > Do the fallback implementations require a new IPI? The fallbacks > could rely on existing mechanisms such as the smp_call_function > family.
Indeed. I'd be worried of using that mechanism for NMIs, but normal IPIs should stick to the normal cross-call stuff.
The jury is still out on why this is a good idea, given that it doesn't work in the only interesting case (deadlocked CPUs).
M. -- Jazz is not dead. It just smells funny...
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