[mythtv-users] Mythtranscode lock up

Tim Tait t.tait at comcast.net
Tue Jun 15 15:30:51 EDT 2004

Michael T. Dean wrote:

> 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 

I've mentioned this on a few other threads, but try getting the 
"athcool" package (debian has it I know, other might) and do "athcool 
off". This shuts off the "CPU Disconnect" feature of the Athlons, 
causing slighty more heat, but eliminating a race condition that occurs 
when interrupts come in while CPU is disonnected from the bus. If you 
search hard enough there is some kernal chat about this. Some patches 
exist which I believe put in long waits before reading interrupt causes 
(slow!). I know it fixed my AU13, which runs rock solid for weeks doing 
builds, when it used to die daily. And the apic is being used. Note that 
some BIOS's allow "CPU Disconnect" to be disabled and some don't.


More information about the mythtv-users mailing list