Re: 2.6.20->2.6.21 - networking dies after random time

Jean-Baptiste Vignaud
2007-08-06T20:42:58Z

Mmm, bad news, after 4 hours of intensive network stressing, one of the 2 3com card failed with the latest fedora kernel.

Aug 6 22:31:09 loki kernel: NETDEV WATCHDOG: eth2: transmit timed out
Aug 6 22:31:09 loki kernel: eth2: transmit timed out, tx_status 00 status e601.
Aug 6 22:31:09 loki kernel: diagnostics: net 0ccc media 8880 dma 0000003a fifo 8000
Aug 6 22:31:09 loki kernel: eth2: Interrupt posted but not delivered -- IRQ blocked by another device?
Aug 6 22:31:09 loki kernel: Flags; bus-master 1, dirty 26085000(8) current 26085000(8)
Aug 6 22:31:09 loki kernel: Transmit list 00000000 vs. ffff81007c807700.

Stressing eth2 by copying large files on a samba on share and eth0 by downloading big files on the internet.

Jb

>
> * Chuck Ebbert <cebbert@redhat.com> wrote:
>
> > Before, they would print:
> >
> > eth0: transmit timed out, tx_status 00 status e601.
> > diagnostics: net 0ccc media 8880 dma 0000003a fifo 0000
> > eth0: Interrupt posted but not delivered -- IRQ blocked by another device?
> > Flags; bus-master 1, dirty 295757(13) current 295757(13)
> > Transmit list 00000000 vs. f7150a20.
> > 0: @f7150200 length 80000070 status 0c010070
> > 1: @f71502a0 length 80000070 status 0c010070
> > 2: @f7150340 length 8000005c status 0c01005c
> >
> > Now they just work, apparently...
>
> could you please try the patch below? If this doesnt do the trick then i
> guess we need to revert that change.
>
> Ingo
>
> ------------>
> (take 2)
>
> Subject: genirq: fix simple and fasteoi irq handlers
>
> After the "genirq: do not mask interrupts by default" patch interrupts
> should be disabled not immediately upon request, but after they happen.
> But, handle_simple_irq() and handle_fasteoi_irq() can skip this once or
> more if an irq is just serviced (IRQ_INPROGRESS), possibly disrupting a
> driver's work.
>
> The main reason of problems here, pointing the broken patch and making
> the first patch which can fix this was done by Marcin Slusarz.
> Additional test patches of Thomas Gleixner and Ingo Molnar tested by
> Marcin Slusarz helped to narrow possible reasons even more. Thanks.
>
> PS: this patch fixes only one evident error here, but there could be
> more places affected by above-mentioned change in irq handling.
>
> PS 2:
> After rethinking, IMHO, there are two most probable scenarios here:
>
> 1. After hw resend there could be a conflict between retriggered
> edge type irq and the next level type one: e.g. if this level type
> irq (io_apic is enabled then) is triggered while retriggered irq is
> serviced (IRQ_INPROGRESS) there is goto out with eoi, and probably
> the next such levels are triggered and looping, so probably kind of
> flood in io_apic until this retriggered edge service has ended.
> 2. There is something wrong with ioapic_retrigger_irq (less probable
> because this should be probably seen with 'normal' edge retriggers,
> but on the other hand, they could be less common).
>
> So, if there is #1, this fixed patch should work.
>
> But, since level types don't need this retriggers too much I think
> this "don't mask interrupts by default" idea should be rethinked:
> is there enough gain to risk such hard to diagnose errors?
>
> So, IMHO, there should be at least possibility to turn this off for
> level types in config (it should be a visible option, so people could
> find & try this before writing for help or changing a network card).
>
>
> Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
>
> ---
>
> diff -Nurp 2.6.23-rc1-/kernel/irq/chip.c 2.6.23-rc1/kernel/irq/chip.c
> --- 2.6.23-rc1-/kernel/irq/chip.c 2007-07-09 01:32:17.000000000 +0200
> +++ 2.6.23-rc1/kernel/irq/chip.c 2007-08-05 21:49:46.000000000 +0200
> @@ -295,12 +295,11 @@ handle_simple_irq(unsigned int irq, stru
>
> spin_lock(&desc->lock);
>
> - if (unlikely(desc->status & IRQ_INPROGRESS))
> - goto out_unlock;
> kstat_cpu(cpu).irqs[irq]++;
>
> action = desc->action;
> - if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
> + if (unlikely(!action || (desc->status & (IRQ_INPROGRESS |
> + IRQ_DISABLED)))) {
> if (desc->chip->mask)
> desc->chip->mask(irq);
> desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
> @@ -318,6 +317,8 @@ handle_simple_irq(unsigned int irq, stru
>
> spin_lock(&desc->lock);
> desc->status &= ~IRQ_INPROGRESS;
> + if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
> + desc->chip->unmask(irq);
> out_unlock:
> spin_unlock(&desc->lock);
> }
> @@ -392,18 +393,16 @@ handle_fasteoi_irq(unsigned int irq, str
>
> spin_lock(&desc->lock);
>
> - if (unlikely(desc->status & IRQ_INPROGRESS))
> - goto out;
> -
> desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
> kstat_cpu(cpu).irqs[irq]++;
>
> /*
> - * If its disabled or no action available
> + * If it's running, disabled or no action available
> * then mask it and get out of here:
> */
> action = desc->action;
> - if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
> + if (unlikely(!action || (desc->status & (IRQ_INPROGRESS |
> + IRQ_DISABLED)))) {
> desc->status |= IRQ_PENDING;
> if (desc->chip->mask)
> desc->chip->mask(irq);
> @@ -420,6 +419,8 @@ handle_fasteoi_irq(unsigned int irq, str
>
> spin_lock(&desc->lock);
> desc->status &= ~IRQ_INPROGRESS;
> + if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
> + desc->chip->unmask(irq);
> out:
> desc->chip->eoi(irq);
>
>