[mythtv-users] Mythtranscode lock up

[Michael T. Dean]

Ryan Steffes wrote:

> Trying to narrow this down, I've got an A7N8X mobo and I'm using 
> kernel options apci=no and nolapic to get it to run mostly stable at all.

I think the options you're looking for are:
  noapic nolapic
and possibly:
  acpi=off
or even:
  pci=noacpi

FYI, APIC is the Advanced Programmable Interrupt Controller and LAPIC is 
the Local APIC (i.e. on the CPU).  ACPI is the Advanced Configuration 
and Power Interface (which handles things like the soft-off power 
switch--allowing you to shutdown nicely with the power button instead of 
powering off a running system), and performs Input/Output- (IO-) APIC 
enumeration.  APCI does not exist (to the best of my knowlege--at least 
not in a context that's relevant to the Linux kernel).  PCI is the 
Peripheral Component Interconnect, the slots into which most expansion 
cards are inserted; the parameter "pci=noacpi" specifies that ACPI 
should not be used for routing interrupt requests or scanning the PCI bus.

Note that you can find information about the available kernel parameters 
in the file Documentation/kernel-parameters.txt in your Linux source 
directory.  This file is available in both 2.4 and 2.6 kernel source trees.

Also, you're not the first to mis-type one of these acronyms--it's 
amazing how many web pages try things like "apic=off" or "noacpi" or 
worse (which probably explains how you found your parameter).  
Unfortuantely, it's really hard to find the right options when there are 
so many wrong pages out there (probably outnumbering the pages that got 
it right).  If using "apci=no" or even "acpi=no" you should be able to 
find a message about an unrecognized kernel option in your boot log.  
BTW, spelling _and_ capitalization is important.

/me stops ranting
(Sorry, the "millions" of pages on the 'net with bad options is a 
pet-peeve of mine, so I wanted to cover all the bases.)

I don't know exactly which options are necessary for your 
motherboard...  Any nForce2 users with more information?

> It's transcoding just fine sometimes and locking up other times.  I'm 
> starting to wonder if there is a correlation between LAN activity with 
> the onboard nic and the lock ups but I'm not entirely sure how to test 
> for it.  I'm just thinking that because a couple times I've been 
> browsing the the web (Firefox 0.8) or using urpmi (4.4.5) to install 
> some other stuff while mythtranscoder was running while it locked up.

Try the parameters above (in multiple combinations, if necessary).  If 
they don't help, it may be worth trying to find out what's causing the 
conflicts, but otherwise, you might be in for a lot of testing which may 
not even provide a solution.

> If I leave my computer unattended, it seems to usually run fine now.

Interrupt problems typically occur on a stressed system--i.e. when 
transcoding or watching LiveTV.

> If this gives a clue to anyone as to something to try ot test, please 
> let me know.

HTH.

Mike