Re: [LAU] Is ALSA using hrtimer?

Many thanks for the explanations. Of course, now I have even more questions :-) Seeking clarification: does this mean the jitter issues affect only using Jack MIDI ? If I'm just using qjackctl to patch between different ALSA midi sources, and am not using jack midi at all, then I won't suffer from the aforementioned jitter issues? My typical use cases involve patching (via qjackctl) ALSA midi to ALSA midi such as: * external midi keyboard --> sequencer (e.g. qtractor or rosegarden) * sequencer --> external midi synth/sampler * sequencer or external midi keyboard --> ALSA synth (e.g. yoshimi or qsynth) In the future, I want to try getting my external MIDI gear to generate midi clock and attempt to sync jack midi and transport to my external gear. Is this where I'll run into problems, as I will need to bridge ALSA midi to Jack midi in order to access the jack transport? What's the most reliable way of slaving Jackd to an external MIDI clock? (as opposed to using http://www.teuton.org/~gabriel/jack_midi_clock/ to slave external devices to jack's midi clock). What are the advantages of using Jack Midi over ALSA midi? Perhaps due to its newness, I only have one synth that uses jack-midi:: http://ll-plugins.nongnu.org/azr3/ -- Is Jack Midi and a2jmidid the direction we should be moving towards in the future, and currently isn't well represented by tools and software because it's newer than ALSA? Thanks! -- Niels. PS: what happens with ALSA and Jack timing when running a "tickless kernel": http://kerneltrap.org/node/6750