[linux-audio-user] 2.6.15.4, realtime-lsm, jackd -R, system performance down!

[fons adriaensen]

On Sun, Feb 12, 2006 at 08:18:10PM -0500, Will Dyson wrote:
>
> On 2/12/06, Ismael Valladolid Torres <ivalladt at punkass.com> wrote:
>
> > Then I try horgand. It takes a lot for it to load, then it sounds
> > nicely, I get no xruns, but my X Window system becomes unresponsive.
> > ...
> 
> How much memory does your machine have? Is it swapping when this
> slowdown occurs?

Good question. This really looks like an 'out of memory' problem.

> 1. The realtime audio thread(s) are as independant of the GUI as possible.
> 
> 2. Only the code and data actually needed by those threads would be mlock()ed.
> 
> I think most jack apps are already written such that 1 is true, and it
> should not be too hard to selectivly mlock() the data buffers used in
> the realtime thread. But I don't know how to tell the Linux kernel to
> mlock() only the code pages used by a certain thread. Doing that
> automaticly seems like a rather hairy technical problem (it may even
> be equivalent to solving the halting problem, i.e. impossible).
> ...

The real solution is to put the UI and RT parts in separate processes.
It's a bit more work, but not so much if you want to have a clean
interface between the two anyway.

-- 
FA