[LAD] jack / sched_deadline

tim tim at klingt.org
Thu Jun 19 19:17:01 UTC 2014

hi leonardo,

> Next week I'll be in Pisa, Italy, for a workshop held by some of the 
> SCHED_DEADLINE guys. I'm not a serious dev but I do research and I'll be 
> glad to evaluate the benefit of SCHED_DEADLINE for audio and jack, 
> compared to SCHED_FIFO.

that would be nice! the interface is much more robust than SCHED_FIFO
and it is rather similar to time-constraint threads as found on mach
threads. and it perfectly maps to rate-monotonic schedulers as found in
audio systems ...
however my initial tests were not very promising: my multicore audio
engine performed worse when using SCHED_DEADLINE for the helper threads
compared to SCHED_FIFO ...


>> since recent kernels provide SCHED_DEADLINE, i'm porting my code to make
>> use of it.
>> * is there any plan to migrate jack1 and/or jack2 to use this scheduling
>> policy for the jack thread(s) of the application?
>> * what is the recommended way to set the scheduling policy of the jack
>> thread with the current API? afaict, the JackThreadInitCallback is
>> called before JackClient::AcquireSelfRealTime in jack2. (i cannot use
>> jack1 due to the old bug that jack corrupts the stack while trying to
>> pre-fault it)

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