Random thoughts, tips & tricks about Slackware-Linux, Lego and Star Wars

NVIDIA "Failed to allocate primary buffer" error

October 12th, 2010 by Niels Horn in , ,

nvidia_logoYesterday I installed Slackware on a computer that came with a Debian-derivative installed. Nothing against Debian, but I'm more used to Slackware, and the hard drive had enough space left…
This box is an all "no-brand / low-price" system, but has very reasonable specs: Quad-core AMD GHz processor, 4GB memory, 400GB hard drive, 6150SE nForce 430 on-board, and - best of all - does *not* come with that paid operating system from Redmond :)
The monitor that came with it is a 20″ Philips model, with 1600×900 maximum resolution.

Installation of Slackware 13.1 went smoothly, as always, except for one thing: the maximum resolution with the NVIDIA driver (built with the script from ) was 1280×1024. This annoyed me and intrigued me at the same time, as the Debian spin-off worked flawlessly at 1600×900. :(

In the /var/log/Xorg.0.log (the first place to look when X does not work the way you expect) I noticed the following strange error message: 

Failed to allocate primary buffer: out of memory

The /etc/X11/xorg.conf created by the nvidia-settings program was almost the same on both Linux flavors, so that was not the problem.

Then I started to check the differences between the two installations…
I noticed that the Debian spin-off used an older kernel and an older version of the NVIDIA driver, but I never had problems with the newer versions on other systems.

Next step: Google.

I found several reports of the same problem, and the "solution" (more like a work-around) was adding the "nopat" parameter to the kernel.
I checked the configuration of the kernel used by Slackware 13.1 (/boot/config) against the configuration used to build the kernel that came with the Debian spin-off and they were different indeed:

in Slackware it is: 

CONFIG_X86_PAT=y

While the other has: 

# CONFIG_X86_PAT is not set

I added the "nopat" parameter in /etc/lilo.conf: 

...
append=" vt.default_utf8=0 nopat"
...

After running lilo and rebooting, the resolution went to 1600×900 without problems! :)

Now it's just a lot of irony that I have to set "nopat" to use Slackware, but I hope forgives me until I compile my own kernel for this box ;)