On Fri, Aug 10, 2007 at 10:30:50AM +0200, Ingo Molnar wrote:
>
> * Jarek Poplawski <jarkao2@xxxxx> wrote:
>
> > > Hmm. This solution is still just pampering over the real problem.
> > > The delayed disable just re-sends level interrupts unnecessarily. I
> > > have a fix (needs some testing) for this, which I send out tomorrow,
> > > when I'm really back from vacation.
> > >
> > > But suppressing the resend is not fixing the driver problem. The
> > > problem can show up with spurious interrupts and with interrupts on
> > > a shared PCI interrupt line at any time. It just might take weeks
> > > instead of minutes.
> >
> > Doesn't it look like a little change of mind? [...]
>
> what change of mind do you mean exactly?
>
> > [...] Well, there are probably (but need more testing) two other
> > solutions: _SW_RESEND and disabling without delay for levels only...
>
> IIRC Marcin tested software-resend and it didnt fix the hang. That
> strongly points in the direction of a driver bug (or a genirq bug) being
> made more prominent by the genirq change - not any hardware detail such
> as the APIC vector-retrigger sequence.
>
> While we'd like to see the suspected driver bug (or any higher level
> genirq bug) fixed, we'll undo the effect of the genirq change (because
> it is causing a regression). We'll also add a separate, optional
> irq-debugging feature that generates high-rate interrupts on any shared
> irq line. (and thus artificially stresses the robustness of the driver
> and the genirq layer against spurious interrupts.)
Not exactly so... I've send modified version of your software-resend
patch, and it seems to work OK.
Jarek P.
>From marcin.slusarz@xxxxxxxxx Wed Aug 8 13:20:02 2007
From: "=?ISO-8859-2?Q?Marcin_=A6lusarz?=" <marcin.slusarz@xxxxxxxxx>
...
Subject: Re: 2.6.20->2.6.21 - networking dies after random time
...
2007/8/7, Jarek Poplawski <jarkao2@xxxxx>:
> So, the let's try this idea yet: modified Ingo's "x86: activate
> HARDIRQS_SW_RESEND" patch.
> (Don't forget about make oldconfig before make.)
> For testing only.
>
> Cheers,
> Jarek P.
>
> PS: alas there was not even time for "compile checking"...
>
> ---
>
> diff -Nurp 2.6.22.1-/arch/i386/Kconfig 2.6.22.1/arch/i386/Kconfig
> --- 2.6.22.1-/arch/i386/Kconfig 2007-07-09 01:32:17.000000000 +0200
> +++ 2.6.22.1/arch/i386/Kconfig 2007-08-07 13:13:03.000000000 +0200
> @@ -1252,6 +1252,10 @@ config GENERIC_PENDING_IRQ
> depends on GENERIC_HARDIRQS && SMP
> default y
>
> +config HARDIRQS_SW_RESEND
> + bool
> + default y
> +
> config X86_SMP
> bool
> depends on SMP && !X86_VOYAGER
> diff -Nurp 2.6.22.1-/arch/x86_64/Kconfig 2.6.22.1/arch/x86_64/Kconfig
> --- 2.6.22.1-/arch/x86_64/Kconfig 2007-07-09 01:32:17.000000000 +0200
> +++ 2.6.22.1/arch/x86_64/Kconfig 2007-08-07 13:13:03.000000000 +0200
> @@ -690,6 +690,10 @@ config GENERIC_PENDING_IRQ
> depends on GENERIC_HARDIRQS && SMP
> default y
>
> +config HARDIRQS_SW_RESEND
> + bool
> + default y
> +
> menu "Power management options"
>
> source kernel/power/Kconfig
> diff -Nurp 2.6.22.1-/kernel/irq/manage.c 2.6.22.1/kernel/irq/manage.c
> --- 2.6.22.1-/kernel/irq/manage.c 2007-07-09 01:32:17.000000000 +0200
> +++ 2.6.22.1/kernel/irq/manage.c 2007-08-07 13:13:03.000000000 +0200
> @@ -169,6 +169,14 @@ void enable_irq(unsigned int irq)
> desc->depth--;
> }
> spin_unlock_irqrestore(&desc->lock, flags);
> +#ifdef CONFIG_HARDIRQS_SW_RESEND
> + /*
> + * Do a bh disable/enable pair to trigger any pending
> + * irq resend logic:
> + */
> + local_bh_disable();
> + local_bh_enable();
> +#endif
> }
> EXPORT_SYMBOL(enable_irq);
>
> diff -Nurp 2.6.22.1-/kernel/irq/resend.c 2.6.22.1/kernel/irq/resend.c
> --- 2.6.22.1-/kernel/irq/resend.c 2007-07-09 01:32:17.000000000 +0200
> +++ 2.6.22.1/kernel/irq/resend.c 2007-08-07 13:57:54.000000000 +0200
> @@ -62,16 +62,24 @@ void check_irq_resend(struct irq_desc *d
> */
> desc->chip->enable(irq);
>
> + /*
> + * Temporary hack to figure out more about the problem, which
> + * is causing the ancient network cards to die.
> + */
> +
> if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
> desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;
>
> - if (!desc->chip || !desc->chip->retrigger ||
> - !desc->chip->retrigger(irq)) {
> + if (desc->handle_irq == handle_edge_irq) {
> + if (desc->chip->retrigger)
> + desc->chip->retrigger(irq);
> + return;
> + }
> #ifdef CONFIG_HARDIRQS_SW_RESEND
> - /* Set it pending and activate the softirq: */
> - set_bit(irq, irqs_resend);
> - tasklet_schedule(&resend_tasklet);
> + WARN_ON_ONCE(1);
> + /* Set it pending and activate the softirq: */
> + set_bit(irq, irqs_resend);
> + tasklet_schedule(&resend_tasklet);
> #endif
> - }
> }
> }
>
Works fine with:
WARNING: at kernel/irq/resend.c:79 check_irq_resend()
Call Trace:
[<ffffffff8025e660>] check_irq_resend+0xc0/0xd0
[<ffffffff8025e1cd>] enable_irq+0xed/0xf0
[<ffffffff8807f21d>] :8390:ei_start_xmit+0x14d/0x30c
[<ffffffff8024d055>] lock_release_non_nested+0xe5/0x190
[<ffffffff80539b78>] __qdisc_run+0x98/0x1f0
[<ffffffff80539b8e>] __qdisc_run+0xae/0x1f0
[<ffffffff8052b65e>] dev_hard_start_xmit+0x26e/0x2d0
[<ffffffff80539ba0>] __qdisc_run+0xc0/0x1f0
[<ffffffff8052dc2f>] dev_queue_xmit+0x24f/0x310
[<ffffffff805337a7>] neigh_resolve_output+0xe7/0x290
[<ffffffff8054f5c0>] dst_output+0x0/0x10
[<ffffffff80552aff>] ip_output+0x19f/0x340
[<ffffffff80551f77>] ip_queue_xmit+0x217/0x430
[<ffffffff80563b2a>] tcp_transmit_skb+0x40a/0x7c0
[<ffffffff805657bb>] __tcp_push_pending_frames+0x11b/0x940
[<ffffffff8055972a>] tcp_sendmsg+0x87a/0xc80
[<ffffffff80577735>] inet_sendmsg+0x45/0x80
[<ffffffff8051e2d4>] sock_aio_write+0x104/0x120
[<ffffffff80285fc1>] do_sync_write+0xf1/0x130
[<ffffffff80243290>] autoremove_wake_function+0x0/0x40
[<ffffffff802868e9>] vfs_write+0x159/0x170
[<ffffffff80286ef0>] sys_write+0x50/0x90
[<ffffffff802097fe>] system_call+0x7e/0x83
-
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