Comment 139 for bug 190754

I just upgraded to 2.6.24-18 kernel as well. At first I was using the rt kernel, which did not behave any better in regards to audio drop outs (than previous versions in Hardy). Of note is that I'm NOT using PulseAudio, but just plain ALSA. I then tried the regular 2.6.24-18 kernel and I have yet to been able to get Rhythmbox to drop out. Using a small test application I wrote which does system calls like malloc() and chdir() and times how long they take, I found that running this app as a normal user with the rt kernel can spike up over 400ms for system calls when doing things like minimizing/maximizing windows, whereas the generic 2.6.24-18 kernel max is under 80ms. I believe the default gstreamer buffer size is 300ms. So there still exist some differences between the rt and non-rt 2.6.24-18 Ubuntu kernel which are causing rather significant system call latencies. Of note though, is that SCHED_FIFO audio applications are able to run on my system with the rt kernel at sub 4ms latency, without issues, so the problem is for the SCHED_OTHER normal user case. I was previously using the rt kernel in Gutsy without these issues, so there is likely still something to be fixed in the latest rt kernel.