Re: [PATCH] genirq: Fix irqs_unhandled in note_interrupt

From: Thomas Gleixner
Date: Mon Feb 19 2024 - 10:04:19 EST


On Tue, Nov 28 2023 at 10:10, Angus Chen wrote:
> Commit 4f27c00bf80f ("Improve behaviour of spurious IRQ detect")
> introduced a age of last_unhandled,after irq_count reached 100000,
> we set irqs_unhandled = 0,but we didn't clear last_unhandled.

We do nothing. Please write changelogs in passive voice.

> So we can see the print of irq_spurious_proc_show is not consistent.
> Like below:
> root@jmkernel:~# cat /proc/irq/138/spurious
> count 99998
> unhandled 1
> last_unhandled 1543930240 ms
>
> root@jmkernel:~# cat /proc/irq/138/spurious
> count 0
> unhandled 0
> last_unhandled 1548915240 ms

I can't figure out what you are trying to demonstrate here.

> we can set last_unhandled=1 as a prompting message.

This makes no sense either.

> Signed-off-by: Angus Chen <angus.chen@xxxxxxxxxxxxxxx>
> ---
> kernel/irq/spurious.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
> index 02b2daf07441..e883df04bdf1 100644
> --- a/kernel/irq/spurious.c
> +++ b/kernel/irq/spurious.c
> @@ -428,7 +428,7 @@ void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret)
> mod_timer(&poll_spurious_irq_timer,
> jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
> }
> - desc->irqs_unhandled = 0;
> + desc->irqs_unhandled = 1;

Why? Just to do some incomprehensible /proc/ output cosmetics instead of
fixing the related procfs function?

Thanks,

tglx