Re: [patch 06/14] genirq: Cache the condition for /proc/interrupts exposure

[Dmitry Ilvokhin]

On Wed, Mar 04, 2026 at 07:55:53PM +0100, Thomas Gleixner wrote:
> show_interrupts() evaluates a boatload of conditions to establish whether
> exposing an interrupt in /proc/interrupts or not.
> 
> That can be simplified by caching the condition in an internal status flag,
> which is updated when one of the relevant inputs changes.
> 
> As a result the number of instructions and branches for reading
> /proc/interrupts is reduced significantly.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxx>
> ---
>  include/linux/irq.h    |    1 +
>  kernel/irq/chip.c      |    2 ++
>  kernel/irq/internals.h |    2 ++
>  kernel/irq/manage.c    |    2 ++
>  kernel/irq/proc.c      |   16 ++++++++++++----
>  kernel/irq/settings.h  |   14 ++++++++++++++
>  6 files changed, 33 insertions(+), 4 deletions(-)
> 
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -99,6 +99,7 @@ enum {
>  	IRQ_DISABLE_UNLAZY	= (1 << 19),
>  	IRQ_HIDDEN		= (1 << 20),
>  	IRQ_NO_DEBUG		= (1 << 21),
> +	IRQF_RESERVED		= (1 << 22),
>  };

nit: IRQF_ prefix doesn't match the IRQ_ convention used by the other
entries in the enum.

[...]

> --- a/kernel/irq/settings.h
> +++ b/kernel/irq/settings.h
> @@ -37,6 +37,9 @@ enum {
>  #undef IRQF_MODIFY_MASK
>  #define IRQF_MODIFY_MASK	GOT_YOU_MORON
>  
> +#define _IRQ_PROC_VALID		IRQF_RESERVED
> +#undef IRQF_RESERVED

The #undef IRQF_RESERVED is a no-op since IRQF_RESERVED is an enum
constant, not a macro. Probably, need to follow the same pattern as
values above to shadow with GOT_YOU_MORON.

Other than that:

Reviewed-by: Dmitry Ilvokhin <d@xxxxxxxxxxxx>