Re: [LAD] JACK and vanilla 3.19.2 startup issue

On 04/04/15 19:08, Harry van Haaren wrote: Not enough information. I recommend starting jackd with strace, so you get an idea what's actually failing. Also read the code that generates said message: https://github.com/jackaudio/jack1/blob/efd4794001db845433a1eff175256fc9a34… The key thing here is system_user_can_rtprio(): https://github.com/jackaudio/jack1/blob/efd4794001db845433a1eff175256fc9a34… This code tries to call sched_setscheduler() with SCHED_FIFO. My bet is that your "almost vanilla kernel" fails to fulfil this request, but strace will tell you for sure. The question is why said call should fail. The only thing that comes to my mind are CGROUPS. Maybe your old kernel comes without, the new kernel supports them and the configuration is set in a way that disables SCHED_FIFO by default. You could of course always diff the two kernel configs and roll your own (or just recompile vanilla 3.19.x with your 3.18 config). Maybe there are new config options that interfere or change the defaults. HTH