Hi, I wrote to the Linux Audio User list and didn't get any bites, so I thought I'd see if anyone here has any advice on this problem I've been having. I've been seeing noticeably worse performance with USB audio devices using 3.4.5 and 3.4.11 PlanetCCRMA fc17 kernels over my old 2.6.33 PlanetCCRMA kernel, and I was wondering if anyone else has experienced this. Running seven instances of OP-X under WINE, for example, consumed about 10% more CPU. I didn't see a similar increase using PCI audio. I also whipped out LatencyTOP to take some readings, and I see that poll_schedule_timeout and pipe_wait seem to be culprits. What is interesting is that the maximum milliseconds reading is staying roughly the same for poll_schedule_timeout, yet the percentage increases as much as 4x or more. I take this to mean that although the worst-case is about the same between the new kernel and the old, that on average it's waiting on this function longer. I'm also seeing consistently more page faults using perf stat. The realtime priorities, in general, look sane, though there may be something I'm missing. What else could I check? I know going from 2.6.33 to 3.4.x is a leap-- have there been any major scheduler changes that might be impacting performance? -Louis -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
