[mythtv-users] Mythbackend VERY unstable. Repetitive errors in log

[Mark Knecht]

On Mon, Sep 14, 2009 at 8:35 PM, Greg Hermsen <g.hermy15 at gmail.com> wrote:
> On Mon, Sep 14, 2009 at 9:55 PM, Mark Knecht <markknecht at gmail.com> wrote:
>>
>> On Mon, Sep 14, 2009 at 7:22 PM, Greg Hermsen <g.hermy15 at gmail.com> wrote:
>> > Hi.  I recently upgraded from Mythbuntu 8.04 to 8.10 and to 9.04.  Along
>> > with the Mythbuntu verion upgrade, I upgraded my CPU to an AMD Quad core
>> > processor and upgraded the mobo.  I have 2 Hauppauge 1600 PCI dual tuner
>> > cards and plenty of available drive space.  I recompiled the drivers for
>> > the
>> > Hauppauge cards after the Mythbuntu upgrade.  My system worked prior to
>> > the
>> > upgrade, but since upgrading the backend has become very unstable.  When
>> > I
>> > reboot, I may be good for a couple hours or as long as a day or 1.5
>> > days.
>> >
>> > My backend log has MANY repeating error repeating error messages.  I
>> > pasted
>> > samples below.  I've run repairs on the database, but that did not fix
>> > the
>> > problem.
>> >
>> > Please help!  I'm at a loss.
>> >
>> > Greg
>>
>>
>> Hi,
>>   I'm sure that this was because HyperThreading was a joke but when I
>> had my backend on a HyperThreaded processor with SMP turned on I had
>> all sort of problems with the backend that were solved by turning it
>> off.
>>
>>   That's all probably fixed now in the code but keep it in the back
>> of your mind if other suggestions don't solve your problems.
>>
>> Cheers,
>> Mark
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>
> Mark, where do you turn SMP on/off?
>
> Thanks,
> Greg

It's a kernel compile option which I figured in this case is probably
turned on by default since it was a quad-core type processor.

Again, my problems were SMP on a HyperThread processor which just
wasn't a good match. I'd be very surprised if this is really a problem
on a true multi-core chip.

There may be a way to disable cores by setting some variable in
/proc/kernel or proc/cpu or someplace like that there's a switch in
there. If not then you have to build a kernl with SMP turned off which
is what I did. (I'm Gentoo here so we build everything - 5 times a
week...)

However I REALLY doubt it's this. I'm just throwing the data in for
completeness.

Cheers
Mark