2023-11-28 02:12:07

by Angus Chen

Subject: [PATCH] genirq: Fix irqs_unhandled in note_interrupt

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.
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

we can set last_unhandled=1 as a prompting message.

Signed-off-by: Angus Chen <[email protected]>
---
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;
}

bool noirqdebug __read_mostly;
--
2.34.1

2024-02-19 15:04:22

by Thomas Gleixner

Subject: Re: [PATCH] genirq: Fix irqs_unhandled in note_interrupt

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 <[email protected]>
> ---
> 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