Trying to debug memory error lockup + kernel panic
 

Greetings. I am having a problem with lockups on a new FC12 box (dual core 3 ghz, 4 gb memory,HDPVR,nvidia 8400gs). This happens reliably when replaying MythTV videos, but also randomly at other times using other apps. Usually but not always this is accompanied by a kernel panic (caps lock + scroll lock lights flash on keyboard).

I did a core dump with kdump and it reports:

Thread 1 (<main task>):
Cannot access memory at address 0xffff880028025b70

I am in the process of running memtest86+ right now, and it's been through several passes without errors. I know it needs to run more, but given the reliability of this problem with MythTV video playback I am wondering if the problem could be in the video card memory.

Does anyone know of a linux (or bootable) tester for video memory? All I am able to find are some things for windoze such as this.

Also is there any way to track that address from the core dump back to a physical location?

Thx,

Steve

Hi,

did you run memtest86 for a longer time (24h minimum) ? This sounds like your memory is not okay.
did you read http://www.av8n.com/computer/htm/kernel-lockup.htm and this Linux journal link.

Both seems to be helpful for you.

Well I didn't run it for 24 hrs but I ran it through 10 passes with no errors indicated. And the thing is, I am only reliably having problems when there some video output operation is going on. It runs fine for days when it's just recording programs, but when I try to play one back, bam. So I'm becoming convinced there is something wrong with the graphics card or its drivers. Thanks for the link, I will check it out.

Hi,

so a software like pc-doctor or some like this (not sure what there exists) can eventually help you determining if your graphics hardware is okay or not. In case that hardware is okay check mailing list for your video driver. Do you use xorg driver? or the closed source nvidia driver?

Someone suggested I try the drivers from nvidia (rather than the ones available via yum) so I'm going to try that.

Might peek here for ideas.

http://www.ibm.com/developerworks/li...brary/l-debug/