PL 5000 Random Reboots

Robert Slade bsd at bathnetworks.com
Sun Sep 11 02:55:45 PDT 2005


Hi,

I have been having problems with random reboots when using the SMP
Kernel on the above Quad processor machine. It occurs with bot 5.4 and
6.0B4. It does not happen with a single processor kernel, well not in
the last 12 hours.

Searching the mailing list and google has thrown up a number of possible
causes:

a. there was an issue with the SMP kernel under load in 5.3 but the
errata says the fix was incorporated in 5.4;

b. there appears to be some problems with with the ACPI with some
machines. Unfortunately, the SMP kernel needs ACPI so turning it off is
not an option. 

c. there appears to be an issue with some network cards and USB with
interupt 'storms'. The machine has 2 network cards both identified in
dmesg as Compaq Netelligent 10/100, athough only one is in use. I am
getting tl0: tx underrun -- increasing tx threshold to 512 bytes when
using vncserver to run xwindows with KDE which maybe related.

It looks like the most likely cause is ACPI, SMP or both, but as ACPI
relates to interups, the interup 'storm' issue could be impacting.
However I do not know enough about the workings of ACPI etc to be able
to judge this. It looks to me that there is a number of things I could
do to isolate the problem:

1. try building a kernel without SMP but with ACPI to see what effect
that has. Question is is this possible with 6.0B4?

2. if the above gives a problem try changing the network cards for
another type.

3. fix the underrun issue but I am not sure how to do that.

I would be grateful for any comments ideas on the way forward as the
machine is quite slow without the SMP kernel.

Thanks

Rob      



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