When more than a minimal load is place upon the synth (more than 2-10% of a single cpu depending on nice settings) the synthesis stops and jack disconnects zynaddsubfx.
The ui remains responsive however the only way to get sound back is to restart the program.
Upping the nice value mitigates it a little however only delays the problem. At best I could use 11% of a single cpu (on a modern quad core system) before running into the problem.
I have a feeling (correct if wrong) that this could be a threading granularity problem. Does zynaddsubfx use real-time threads on linux for it's main audio thread? Does the zynaddsubfx architecture lend itself to it?
While I have made small patches to other synths before I am not familiar with zyn's code base, any pointers as to where to start trying to resolve?