On 12/12/2010 01:03 PM, ailo wrote: > I've been looking around for any tests made comparing the different > kernels, -rt, generic, or any other type of realtime enchanced kernel. > I haven't found any test results yet, at least none audio related. I did > find some testing tools at rt.wiki.kernel.org, but don't know if and how > they could be made relevant to audio low latency testing. > > I suppose the most interesting results would come from testing different > kernels with jack/alsa and jack/ffado. > > Has anyone done such tests? It is not trivial to perform such tests and AFAIK there's no benchmark suite to automate the process. There are a few tools to test JACK's realtime performance: - the ardour-source includes `tools/jacktest.c` checks for the max DSP load at which an x-run occurs. - http://wiki.linuxaudio.org/wiki/jack_latency_tests git://rg42.org/latentor is a tool to automate measuring round-trip audio latency iterating all JACKd -n/-p/-S parameters However latentor is a pretty recent development and does not yet report x-runs. We watch qjackctl's icon for now. AFAICT there's no recipe. It's a matter of knowing some internals about RT-linux to come up with a proper kernel .config and doing real-life tests. I think it is impossible to assign a number "suitability for pro-audio" to a kernel. For testing performance of the 64studio RT kernel: I do run a couple of heavy-sessions (e.g. 16 jconvolvers in a 16 track ardour session + jamin which procudes quite some DSP, system and IO load). If there's no x-run at 32fpp*2p/48kHz after 24 h while I to surf the web and read email and compile another kernel in the meantime I bless the build OK :) There's a few additional things: wifi, suspend/resume, freq scaling, etc on the checklist, too. 2c, robin _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
