Subject: Re: [PATCH 2/3] genirq: use runtime constant to optimize handle_arch_irq access

From: Thomas Gleixner <[email-masked]>
Date: Sun, 22 Feb 2026 23:06:11 +0100

On Fri, Feb 20 2026 at 17:09, Jisheng Zhang wrote:
> Currently, on GENERIC_IRQ_MULTI_HANDLER platforms, the handle_arch_irq
> is a pointer which is set during booting, and every irq processing needs
> to access it, so it sits in hot code path. We can use the
> runtime constant mechanism which was introduced by Linus to speed up
> its accessing.

The proper solution is to use a static call and update it in
set_handle_irq().  That removes the complete indirect call issue from
the hot path.

Thanks,

        tglx