Good report, thanks for all the info. Joel White <cv223@xxxxxxxxxxx> writes: > With 2.6.9 - In Duplex mode, xruns occur at a rate of scores per min > of recording on *either* drive. Kernel latency trace indicates that > the max kernel latencies were around 200 - 400 usec. Xruns are > eliminated when Jack is set to Capture only. > 3. It seems that there is some kind of interaction between Ardour, > the kernel, and the disk system. The fact that xrun behavior is so > different between the two kernels (xruns on the IDE drive with 2.6.9, > but not 2.4.23) suggests something is up with the kernel. The > latency_trace on 2.6.9 does not report that the kernel latency is the > problem, but it is clearly something going on with this kernel. It is > certainly possible that I have something misconfigured (Lee Revell > checked out my .config, so at least that seems ok). I can send more > info to anyone who may be able to help. I recently built 2.6.9 to test the latest realtime-lsm LKML patch. The patch worked, but realtime performance was horrible on my system, especially compared to 2.6.8.1. I ran JACK in Duplex mode with ardour and jamin. Next, I built 2.6.9-mm1, and things are working pretty well. So, despite not having done a careful test like yours, I think there is a latency problem with 2.6.9. I'd be very interested to see what happens if you run your test on 2.6.9-mm1. The kernel developers probably would, too. -- joq
