I recently installed Fedora Core 6 (with a 2.6.18.1 kernel) on my Intel G965 motherboard based PC. AGP was built in the kernel by default, and agpgart created /dev/agpgart by recognizing 965G graphics chipset well.

However, I compiled and installed a 2.6.18.2 kernel with the exact same configuration as the old one. This time, agpgart does show in dmesg as Linux agpgart interface v0.101 (c) Dave Jones but there are no devices listed below it. Consequentially, no /dev/agpgart device is created.

I just can't figure out why would it behave like this when configurations are exactly the same. I'll be thankful if anyone can provide me with some guidance on this issue.

P.S. Both of the kernels also had intel-agp built in them.

Problem solved. Intel G965 support wasn't included in 2.6.18 line kernels. Redhat backported it from 2.6.19 ones.