Hi Ewan,
In my experiences of RT kernels, they usually slow down graphics. This is
due to the way the RT works, and is unavoidable, actually its precisely
what you want! Sounds confusing but let me explain:
Ie: The audio thread's of a program can get all the attention if they want
it, and the GUI won't update unless there's spare CPU time. The result is
that there should be less audio drop outs under heavier load, but the
screen won't redraw as much, niether will the network card get attention,
etc.
You can define the "priorities" using interrupts for hardware, and using RT
scheduling (SCHED_FIFO) in programs.
Sorry if you knew this already! -Harry
PS: Regarding the audio dropping out for Mixxx... I don't know why that
would happen. But perhaps look into your interrupts ( $ cat
/proc/interrupts ), and make sure that your audio card has a lower
interrupt than your graphics adapter, mouse, usbs etc...
On Wed, Nov 9, 2011 at 2:01 AM, ewan colsell <[email protected]> wrote:
> after a bit of testing i found the same problem in other programs so
> i't not mixxx's fault.
>
> i was really impressed by the latency differnce between linux and windows.
>
> and so dissapointed that it doesent work in ubuntu11.11!
>
> even though i'm using the same kernel version: 3.0.0-13 on both the
> laptop 11.11 and the netbook 11.04; this was using the same interface
> (bcd3000)
>
> i guess i'll try to install 11.04 on the laptop and see what happens.
>
> i'd recomend that everybody tries a rt_prempt kernel, all you have to
> do is add a repository, install a package and restart.
>
>
> https://launchpad.net/~abogani/+archive/ppa
>
>
> ewan.
>
>
>
>
> On 9 November 2011 01:38, RJ Ryan <[email protected]> wrote:
> > Hey Ewan,
> > We don't actually test with or recommend realtime kernels since they can
> be
> > notoriously unstable depending on your hardware and on bugs in Mixxx. I'm
> > not sure why the waveforms would move so slowly but it likely has to do
> with
> > your audio drivers not playing nice with the realtime kernel. It's also
> > possible that either we or PortAudio have a bug.
> > It's very encouraging that you're getting such good results with the
> > low-latency kernel. We should look into whether we should recommend
> people
> > to install that for running Mixxx.
> > thanks,
> > RJ
> > On Tue, Nov 8, 2011 at 6:31 PM, ewan colsell <[email protected]> wrote:
> >>
> >> i just tried xubuntu oneric with the realtime kernel from abogani on
> >> my spare laptop
> >>
> >> unfortunatly with the realtime kernel mixxx's waveforms crawl along in
> >> slow motion and i can't hear anything
> >>
> >> with the generic kernel however things are good at 5.8ms latency on this
> >> laptop.
> >>
> >>
> >> is this a known issue? or should i be reporting a bug to the kernel
> >> maintainer?
> >>
> >>
> >> i have a netbook that runs at 2.9ms with a lowlatency kernel from the
> >> same repository on xubuntu 11.04
> >>
> >>
> >> ewan.
> >>
> >> --
> >> http://www.ewancolsell.com/
> >>
> >>
> >>
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> >
>
>
>
> --
> http://www.ewancolsell.com/
>
>
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