Re: 2.2.14 SMP 3com905: transmit timed out: Odd lost irq and ip-stack lockup

From: Dr. Michael Weller (
Date: Fri Oct 13 2000 - 03:11:09 EST

On Fri, 13 Oct 2000, Andrew Morton wrote:

> "Dr. Michael Weller" wrote:
> >
> > Dear list,
> >
> > I run a Compaq Proliant 1500 (dual Pentium 75.200) with hardware raid
> > (Smart2) with two ethernet cards 3com905 (b or c, I can't tell you right
> > now) as a firewall and web/mail virus scanner which (needless to say)
> > needs to be up 7d/24h.

They are two 3Com 3c905B Cyclone 100baseTx cards, btw.

> > Oct 9 17:29:02 fwintern kernel: eth0: Interrupt posted but not
> > delivered -- IRQ blocked by another device?
> This is the infamous APIC bug. I have about ten reports of this over a
> four-month period. Mark Hemment mentioned it just yesterday.

> Donald Becker says that this is a software bug (I don't know why he
> thinks this). He says that he _always_ boots linux with the `noapic'
> option to prevent it happening.

Question: I thought the APIC was very important for SMP and SMP
performance. Would the machine still work as SMP with noapic (well, I can
just try, I know).

> > The problem was reproducible (several times) with the same download (a
> > 300MB file) after a reboot.
> Interesting. So you had a stable 2.2.14 machine which suddenly started
> repeatedly exhibiting this problem? Is it still reproducible?

Yes, No. In more detail: The machine is a firewall/virus scanner for a
company network. It worked 100% reliably, however a 300MB iso image
download triggered the problem repeatedly. Right now I cannot reproduce
the problem anymore. However, it seems bandwuitdh to the internet is
currently a bit slower. You said it's related to the IRQ frequency. The
machine serves a 2Mbit internet link only. I'd guess its normally not
stressed enough. Except with this long relatively fast (~1.5Mbit when it
crashed) download.



Michael Weller:,, or even If you encounter an eowmob account on any machine in the net, it's very likely it's me.

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