Comment 50 for bug 271070

There is a huge number of people that seem to be having different problems with intrepid, and multi-core amd64.

I have an Asus M3N78-VM motherboard with 4GB RAM and integrated NVIDIA 8200 GPU and dual-core AMD 6000.

I get the following message when booting with Intrepid with every kernel I've tried (2.6.27-4 - 2.6.27-10)

[ 0.004000] Aperture pointing to e820 RAM. Ignoring.
[ 0.004000] Your BIOS doesn't leave a aperture memory hole
[ 0.004000] Please enable the IOMMU option in the BIOS setup
[ 0.004000] This costs you 64 MB of RAM

I get rid of the message, and find the my system is most stable when I boot with iommu=noaperture,memaper=3

However, I reliably get system freezes (blank screen, solid colour), especially when using networking (Atheros wifi chipset, with ath9k driver). The system is solid, even with the accelerated NVIDIA drivers, if I use only a single core (obviously not desirable), by booting with "maxcpus=1"

This freezing I experience is UNRELATED to aperture issue.... I was able to prove this on my system by limiting the memory to less that 4GB and disabling iommu and any aperture.... and I'd still get system freezes (which could be eliminated with maxcpus=1) (In fact some of you may want to try that.... my understanding is that iommu and the aperture is only required for memory >= 4GB... so disable it and try limiting your memory in grub)

For those experiencing the booting problem above, I suggest you try booting
1) with "iommu=noaperture,memaper=3"
2) with "maxcpus=1"
3) with both "iommu=noaperture,memaper=3 maxcpus=1"

and report here if it makes any difference.