[Jack-Devel] advice on xruns

Anyone have an in depth treatise on xruns and how to minimize them. By that I dont mean just adjusting the buffer size, I mean really getting into the gears of why xruns happen and how to potentially minimize them. Reason I ask is that I use jack on a live music basis amd it is crucial for me to get no more than 2.9ms latency. I can hear and feel every latency above above that. I am lucky with mixbus and jack on Linux to get 2.9ms with the occasional xrun every 2 minutes, but I want to see if I cannot eliminate them. Any advice or point to very relevant reference material will be appreciated. Thanks