RH ES 4.0 SMP hangs at boot (&%$*!!11!!) - Solved (sort of)

[David Tonhofer, m-plify S.A.]

No answer from the list but I found out that adding "noapic"
to the kernel boot parameters makes the SMP kernel run just fine.

As "noapic" apparently means "less performance" (the first processor
will handle all the interrupts). From a sourceforge posting:

------
(...apic means:...)

1. more IRQs available, so less IRQ sharing.
2. reduced overhead and reduced performance side effects of taking each
interrput.

The benefit of the 1st one is probably overblown, unless you have tons
of devices.  The benefit of the 2nd, however, is something that gets
worse over time as hardware designers continue to assume that nobody in
their right mind would run a high performance system in PIC mode.  An
interrupt acknowledge cycle over the bus is a tragic thing to witness;-)
------


I tried this trick too: setting the SMP handling in the BIOS from
MPS 1.4 to MPS 1.1. This does not solve the problem though.

Additionally, unsetting the 'Plug and Play' option in the BIOS may
help. The BIOS in this case does not have such an option though.

Additionally, disabling "USB legacy"  option in the BIOS may
help. As it was already disabled, this is not going to help me.

A look through Redhat bugzilla does not yield much.

So I will keep the "noapic". I don't think this warrants a Bugzilla
entry.



Some docs:

I/O APIC and PIC explained (in German):

   <http://www.hardtecs4u.com/reviews/2002/irq/>

Decription of the I/O APIC on my motherboard: Intel® 82870P2 PCI/PCI-X 64-bit Hub 2

   <http://www.intel.com/design/chipsets/e7500/datashts/290732.htm>

PnP option. SuSE gives better Google hits than Red Hat:

   <http://portal.suse.com/sdb/de/2000/05/intnull.html>


<https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=159082>




> Hi,
>
> I have an Fujitsu-Siemens RX200 dual-XEON (with Hyperthreading, 32 bit)
> machine. It worked very well under RH AS 3. A reinstall to RH ES 4
> however brings grief: The 2.6.9-22.0.1.ELsmp kernel hangs at boot
> right after "Booting the kernel". The non-SMP kernel boots nicely.
> I have tried to boot w/o the bootime 'quiet' option but don't get
> any more messages.
>
> Next I will remove all the additional PCI cards from the server to
> see whether anything changes.
>
> Any additional hints? I checked Bugzilla and the Google but so far
> to no avail.
>
> Best,
>
> -- David