Re: [patch 03/12] x86/irq/64: Adjust the per CPU irq stack pointer by 8

[Peter Zijlstra]

On Thu, Feb 04, 2021 at 09:49:06PM +0100, Thomas Gleixner wrote:
>  Move the definition
> next to the inuse flag so they end up in the same cache line.

> -DEFINE_PER_CPU(struct irq_stack *, hardirq_stack_ptr);
> +DEFINE_PER_CPU(void *, hardirq_stack_ptr);
>  DEFINE_PER_CPU(bool, hardirq_stack_inuse);

Not strictly guaranteed they end up in the same line. If you stick them
in a struct and force alignment on the instance you'll have better
guarantees.