[PATCH v6 01/29] irq/matrix: Expose functions to allocate the best CPU for new vectors

Thomas Gleixner tglx at linutronix.de
Sat May 7 05:48:28 AEST 2022


Ricardo,

On Thu, May 05 2022 at 16:59, Ricardo Neri wrote:
> Certain types of interrupts, such as NMI, do not have an associated vector.
> They, however, target specific CPUs. Thus, when assigning the destination
> CPU, it is beneficial to select the one with the lowest number of
> vectors.

Why is that beneficial especially in the context of a NMI watchdog which
then broadcasts the NMI to all other CPUs?

That's wishful thinking perhaps, but I don't see any benefit at all.

> Prepend the functions matrix_find_best_cpu_managed() and
> matrix_find_best_cpu_managed()

The same function prepended twice becomes two functions :)

> with the irq_ prefix and expose them for
> IRQ controllers to use when allocating and activating vector-less IRQs.

There is no such thing like a vectorless IRQ. NMIs have a vector. Can we
please describe facts and not pulled out of thin air concepts which do
not exist?

Thanks,

        tglx


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