Re: need help on a DEADLOCK problem related to function try_one_irq()

[Edward Donovan]

Yes, I will try to do that in the next couple days.  Thanks -

Ed


On Mon, Nov 26, 2012 at 3:09 AM, Wang, Warner <warner.wang@xxxxxx> wrote:
> Hi Thomas and Edward,
>
> This patch works fine for our problems, but I'm not sure if it works for the recent submit "genirq: fix regression in irqfixup, irqpoll" "52553ddffad76ccf192d4dd9ce88d5818f57f62a", which submitted by Edward Donovan.
>
> Edward can you help verify it on your environment?
>
>
> Thanks,
> -Warner
>
> -----Original Message-----
> From: Thomas Gleixner [mailto:tglx@xxxxxxxxxxxxx]
> Sent: 2012å11æ23æ PM 5:09
> To: Wang, Warner
> Cc: Wang, Song-Bo (Stoney)
> Subject: Re: need help on a DEADLOCK problem related to function try_one_irq()
>
> On Thu, 22 Nov 2012, Thomas Gleixner wrote:
>
>> Warner,
>>
>> On Thu, 22 Nov 2012, Wang, Warner wrote:
>>
>> please send such bug reports to the kernel mailinglist in the future.
>>
>> > We met a problem on some of our x86 server and after a few weeks
>> > trace-down effort, we believe the problem is in the file
>> > "linux/kernel/irq/spurious.c".  We created a patch but we are not
>> > 100% sure if it is correct or complete.  That is why we want to
>> > consult you.
>>
>> You spotted the problem right, but I'm not sure at the first glance,
>> whether this is correct. I need to go back into history and figure out
>> why we added that call in the first place. It looks fundamentally
>> wrong.
>>
>> Thanks for analyzing it. I'll keep you posted on my findings.
>
> Can you try the patch below ?
>
> Thanks,
>
>         tglx
>
> ---
>  kernel/irq/spurious.c |    8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
>
> Index: tip/kernel/irq/spurious.c
> ===================================================================
> --- tip.orig/kernel/irq/spurious.c
> +++ tip/kernel/irq/spurious.c
> @@ -80,13 +80,11 @@ static int try_one_irq(int irq, struct i
>
>         /*
>          * All handlers must agree on IRQF_SHARED, so we test just the
> -        * first. Check for action->next as well.
> +        * first.
>          */
>         action = desc->action;
>         if (!action || !(action->flags & IRQF_SHARED) ||
> -           (action->flags & __IRQF_TIMER) ||
> -           (action->handler(irq, action->dev_id) == IRQ_HANDLED) ||
> -           !action->next)
> +           (action->flags & __IRQF_TIMER))
>                 goto out;
>
>         /* Already running on another processor */ @@ -104,7 +102,7 @@ static int try_one_irq(int irq, struct i
>         do {
>                 if (handle_irq_event(desc) == IRQ_HANDLED)
>                         ret = IRQ_HANDLED;
> -               action = desc->action;
> +               action = action->next;
>         } while ((desc->istate & IRQS_PENDING) && action);
>         desc->istate &= ~IRQS_POLL_INPROGRESS;
>  out:
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/