[LAU] Are RT-patches needed anymore? (Was Re: >= 2.6.27 RT ETA? )

[Cassiel]

Hi again,

debian stock kernels are not rt. In order to work with lower latencies and
boost audio performance you need to patch the generic kernel.

A fix for midi should be in this rt patch
http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.26.8-rt16.bz2(but
I am not sure) and higher. Otherwise you can download the patch here
http://offog.org/stuff/rt-200901/tasklets-fix-tasklet_hi_action.patch

Actually I am on 2.6.29-rt-vanilla, debian way compiled, on testing/squeeze
but I did it on lenny a couple of days after it was released.

When compiling from vanilla sources you must prevent compiler warnings to
stop building by checking "Kernel hacking" -> "Continue building despite
compiler warnings" and then go with make-kpkg as usual on debian.

regards
r


2009/3/10 alex stone <compose59 at gmail.com>

>
>
> On Tue, Mar 10, 2009 at 4:06 PM, Cassiel <raffaele.morelli at gmail.com>wrote:
>
>> generic or custom (rt patched) kernel?
>> r
>>
>> 2009/3/10 nescivi <nescivi at gmail.com>
>>
>>>
>>> realtime priorities were handled through limits.conf, and I am running on
>>> the
>>> Debian kernel 2.6.26-1-amd64 on a Intel Core2 Duo, T7500 2.20 GHz. (It's
>>> a
>>> Lenovo Thinkpad T61).
>>>
>>> The previous Debian kernel 2.6.24, did give me better results with JACK,
>>> but
>>> had problem with the serial chip driver (the FTDI), at certain baudrates.
>>>
>>> So yes, the few xruns were problematic, since my soundtrack was the only
>>> sound
>>> that was going on, and I would really like to know how I could make this
>>> whole setup a bit more robust.
>>>
>>> The video capturing and the visualisation are certainly less time
>>> critical, as
>>> I am only deriving control data from it, and/or using it to monitor. It
>>> is
>>> not projected out again.
>>>
>>> sincerely,
>>> Marije
>>
>>
>>
>>
>> _______________________________________________
>> Linux-audio-user mailing list
>> Linux-audio-user at lists.linuxaudio.org
>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
>>
>
> For what it's worth, and i'm certainly not a kernel or linux expert by any
> stretch of the imagination, I've just built (via the debian build method) an
> RT kernel from vanilla, and Igno's patches, for 2.6.26-(rt16 build). As i
> understand it, 2.6.26-rt8, and previous, had a problem with sound and midi.
> I did read a discussion about this, in which a clever fellow had built a
> patch to remedy the problems, and it was intimated that this patch would be
> included in subsequent rt<number> builds.
>
> I don't know if this has happened, but here, on Debian 5 32bit, i'm running
> jack2, with Alsa 1.0.19, 128-n3, and have no problems. No xruns, or glitches
> so far. (The kernel is still warm from a few days ago).
>
> I have a question related to this.
>
> Is it possible to build a custom RT kenel using 2.6.29, that will work in
> Lenny? Is there an incompatability with Glib, or anything else, that will
> prevent this happening?
>
> Alex.
>
>
> --
> Parchment Studios (It started as a joke...)
>
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