[clue-tech] Ubuntu lock-up problems

[dennisjperkins at comcast.net]

----- Original Message ----- 
From: "Michael J. Hammel" <mjhammel at graphics-muse.org> 
To: "CLUE tech" <clue-tech at cluedenver.org> 
Sent: Monday, February 2, 2009 8:28:38 AM GMT -07:00 US/Canada Mountain 
Subject: Re: [clue-tech] Ubuntu lock-up problems 

On Sun, 2009-02-01 at 18:55 -0700, Dennis J Perkins wrote: 
> This might make the problem more tractable. Assuming it's not the 
> kernel, I can try killing background processes and see if it still locks 
> up. 

System lockups cannot occur in user space. That's the design intent of 
kernel vs user space. You can tell if its a user-level process (thus 
knowing if killing it would help) by pinging the box after the lockup. 
If it responds then the kernel is still running. If not, and you don't 
have pings blocked on that box, then the kernel is locked up and killing 
user space daemons may or may not have any affect depending on what 
kernel drivers they interact with directly. 

If you're lucky then an ssh or telnet session might still work after the 
lockup, in which case its definitely video related on the laptop. I had 
this sort of problem for a while last year using NVidia's drivers. The 
newest open source drivers (or at least the stuff in Fedora's RPM Fusion 
repositories) works fine now. 

And you may still have a video driver loaded into the kernel even if X 
is not running. The driver may be getting loaded to do some kind of 
framebuffer interaction. 

You might try booting some other LiveCDs with older kernels just to see 
if anything boots and stays up. Try PuppyLinux (small kernel) or an 
older Knoppix. Or some distro that doesn't do much in the way of video. 

-- 
Michael J. Hammel Principal Software Engineer 
mjhammel at graphics-muse.org http://graphics-muse.org 
------------------------------------------------------------------------------ 

Should not occur in user space. User-space interaction with a driver, such as udev, might cause a lockup in a few cases. There are some reports of problems with a wireless network driver locking things up, and problems with the Radeon driver. I think the problem is with the Xorg driver, but the kernel does have a Radeon module that I had overlooked. I can see if that is loaded. 

The Arch Linux CD doesn't cause lockups. I would just install that and be done with it, but I'm giving this computer to someone who has never used Linux. 

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