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

alex stone compose59 at gmail.com
Tue Mar 10 09:54:12 EDT 2009


On Tue, Mar 10, 2009 at 4:45 PM, Cassiel <raffaele.morelli at gmail.com> wrote:

> 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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> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user



Cassiel,
You have it, and it was the rt16 patch i used. Seems to work fine.

Thanks for the 2.6.29 info.
I may have a go at this sometime in the next couple of days, and i
appreciate the tips, and advice.

Alex.



-- 
Parchment Studios (It started as a joke...)
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