SMP Support for AMD Athlon MP motherboards

SMP Support for AMD Athlon MP motherboards

[Andre Tomt]

I recently got my hands on a unreleased evaluation AthlonMP motherboard with
two 1.1Ghz Athlon CPU's. First thing I tried was of course Linux. I ran into
some problems, however.

1. the SCSI subsystem hung during loading. Before anything card-specefic
driver loaded. SMP og non-SMP kernels, same thing. Modular loading of
scsi-drivers did the same thing upon loading. Full lockup. Got it partly
working on an IDE drive after a while.

2. Linux did only see one CPU.

3. It were highly unstable, even in non-SMP mode.

Whats the degree of support in Linux for such an AMD mobo? Is the Athlon MP
architecture supported at all yet?

I managed to get FreeBSD running on it, and use the SCSI-controller
(Adaptec, not sure about what board since I do not have physical access as I
write this. Uses the aic7xxx driver, u160scsi). However, FreeBSD would not
boot in SMP mode (scsi lockup like Linux did in both SMP and non-SMP
kernels, it did see both CPU's however...).

Now, shed some light on this. I tried kernels fram 2.0.3x to 2.4.7, 2.0 and
2.2 did alot of really strange stuff, like making user space apps saying
"You do not exist"(?).

How is the support for AMD Athlon MP, really :-)

--
Regards,
André Tomt

Re: SMP Support for AMD Athlon MP motherboards

[Chris Wedgwood]

On Sun, Aug 05, 2001 at 05:55:22AM +0200, Andre Tomt wrote:

    I recently got my hands on a unreleased evaluation AthlonMP
                                 ^^^^^^^^^^^^^^^^^^^^^
    motherboard with two 1.1Ghz Athlon CPU's. First thing I tried was
    of course Linux. I ran into some problems, however.

Linux does support this, and people are using it --- with no
major problems.

Maybe your board is busted?  If you think that not the case, please
try 2.4.7+ and report specifically what the problems are in more
detail if you can (ie. supply dmesg from boot, etc).




Anyhow, you 2.2.x you need something very recent, maybe 2.2.20+ I
think.




  --cw

Re: SMP Support for AMD Athlon MP motherboards

[Johannes Erdfelt]

On Sun, Aug 05, 2001, Chris Wedgwood <cw@f00f.org> wrote:
> On Sun, Aug 05, 2001 at 05:55:22AM +0200, Andre Tomt wrote:
> 
>     I recently got my hands on a unreleased evaluation AthlonMP
>                                  ^^^^^^^^^^^^^^^^^^^^^
>     motherboard with two 1.1Ghz Athlon CPU's. First thing I tried was
>     of course Linux. I ran into some problems, however.
> 
> Linux does support this, and people are using it --- with no
> major problems.
> 
> Maybe your board is busted?  If you think that not the case, please
> try 2.4.7+ and report specifically what the problems are in more
> detail if you can (ie. supply dmesg from boot, etc).

All of the 2.4 kernels that worked on PIII systems worked on my Dual
Athlon.

> Anyhow, you 2.2.x you need something very recent, maybe 2.2.20+ I
> think.

Only for SMP. Atleast all of the later 2.2 kernels worked fine with the
Tyan MP Athlon board with the UP kernel.

To get SMP working you need to apply the patches I created. They just
got to Alan and I don't think they're in 2.2.20pre yet, but it sounds
like they'll be in there soon.

Anyway, it sounds like a hardware problem.

JE

Re: SMP Support for AMD Athlon MP motherboards

[Paul G. Allen]

Andre Tomt wrote:
> 
> I recently got my hands on a unreleased evaluation AthlonMP motherboard with
> two 1.1Ghz Athlon CPU's. First thing I tried was of course Linux. I ran into
> some problems, however.

First of all, I have a K7 Thunder with dual 1.4GHz Thunderbird CPUs, 1
ATA100 (IBM) drive, and 1 U160 (also IBM) drive. I have a friend with
the same board using dual 1.2GHz MP CPUs. They both work fine.

> 
> 1. the SCSI subsystem hung during loading. Before anything card-specefic
> driver loaded. SMP og non-SMP kernels, same thing. Modular loading of
> scsi-drivers did the same thing upon loading. Full lockup. Got it partly
> working on an IDE drive after a while.

Which release of Linux? I started with Red Hat 7.1 and it works with
both SMP and non-SMP kernels, Athlon and PIII compiled kernels, and with
a single CPU installed as well as both CPUs. I now have the original
2.4.2-2 SMP kernel, a UP 2.4.2-2 kernel, a 2.4.7 kernel, and a modified
2.4.x SMP kernel that all work fine.

>From what you say below, it sounds like it uses an onboard Adaptec 7899P
SCSI controller, so Linux 2.4.2-2 (Red Hat Seawolf) should work fine.
Make sure your termination and SCSI BIOS settings are correct (if BSD
works, they are probably OK).

> 
> 2. Linux did only see one CPU.

Both CPUs need to be configured the same as far as FSB speed. I don't
know what your board will do, or even if you can change the settings,
but mine would not even POST when the two CPUs were set for different
FSB speeds. (Tyan warns that setting the two differently can damage the
MoBo. What a nice thing to see when you find that yours is configured
wrong. I'm glad I only had a single CPU installed at the time. :)

> 
> 3. It were highly unstable, even in non-SMP mode.

Early versions of the AMD760MP chipset had serious problems. One of
these was a DMA issue that may cause this. If you can set the results of
lspci -x, we can tell you if your MP chipset may suffer from any (known)
anomalies.

My system has been running 24/7 for weeks and only gets rebooted to test
new kernel builds (about once or twice every night.)

> 
> Whats the degree of support in Linux for such an AMD mobo? Is the Athlon MP
> architecture supported at all yet?

More or less. The chipset works fine for the most part, but not all the
features are fully supported. It also depends upon the BIOS. My BIOS has
some problems, for example it does not set up the MTRRs on both CPUs
properly and there are no settings for AGP and PCI modes (unlike my Asus
A7V133, that seems to have just about everything, too bad the thing is
so unstable)

> 
> I managed to get FreeBSD running on it, and use the SCSI-controller
> (Adaptec, not sure about what board since I do not have physical access as I
> write this. Uses the aic7xxx driver, u160scsi). However, FreeBSD would not
> boot in SMP mode (scsi lockup like Linux did in both SMP and non-SMP
> kernels, it did see both CPU's however...).

Sounds like a hardware problem.

> 
> Now, shed some light on this. I tried kernels fram 2.0.3x to 2.4.7, 2.0 and
> 2.2 did alot of really strange stuff, like making user space apps saying
> "You do not exist"(?).
> 
> How is the support for AMD Athlon MP, really :-)

Start with Red Hat 7.1. I know it works out of the box. If that doesn't
work, I'd look at hardware, BIOS configuration, board jumpers (if any),
and the like.


That's about all that comes to mind at the moment.


PGA

-- 
Paul G. Allen
UNIX Admin II/Network Security
Akamai Technologies, Inc.
www.akamai.com

Re: SMP Support for AMD Athlon MP motherboards

[Andre Tomt]

> To get SMP working you need to apply the patches I created. They just
> got to Alan and I don't think they're in 2.2.20pre yet, but it sounds
> like they'll be in there soon.

I noticed a few patches lying around, after I got home 05:00 AM :-)

> Anyway, it sounds like a hardware problem.

Mhm, the board behaves beatiful under Windows 2000. Could still be a
hardware problem, tho.
I'll hook up a serial console later today and see what I can get out of it.

Re: SMP Support for AMD Athlon MP motherboards

[Alan Cox]

> Whats the degree of support in Linux for such an AMD mobo? Is the Athlo=
> n MP
> architecture supported at all yet?

It is supported yes. You should have seen both processors and stability

Alan