Here is my so far experince for those interested: I could not find a realtime-preempt patch that will apply correctly to a recent 2.6.12 kernel. It could be that some combination of 2.6.12 and realtime-preempt-2.6.12-final will work but I decided to give up. All attempts resulted in rejected hunks, -R?, and/or missing files (which file to patch:). No compilable kernel ever resulted. The two patches I tried are realtime-preempt-2.6.12-final-V0.7.51-38 and realtime-preempt-2.6.12-rc6-V0.7.48-37. Kernel was 2.6.12.5 (when did they add the extra number btw??)....I haven't tried straight up 2.6.12 yet and that may be worth while. 2.6.13-rc6 has some of the realtime preempt patch in it already but it is incomplete. Applying the patch results in a kernel that won't compile for the amd64. 2.6.11.12 can be patched with realtime-preempt-2.6.11-rc4-V0.7.39-02 with success. It compiles on the amd64 and seems to work. I had to use the realtime-lsm patch with it instead of RT-RLimits because the later doesn't seem to exist as a seperate entity from the kernel anymore...even for old versions...or at least I couldn't find it anywhere. Using realtime-lsm was easy as I just did an "emerge realtime-lsm" and set up the gid to audio when loading the module...requires no PAM patch even though I already did one. Right now, without some more serious testing, I am leaning toward the older 2.6.11.12 as the more viable kernel for this computer. I have it set up with complete preemption and it seems to respond quite well to that setting. I still have yet to figure out which entry, if any, in /proc/interrupts is my soundcard but I'll deal with that when I can.
