4:14 p.m.
On Mon, 2008-12-01 at 14:41 -0700, David Nielson wrote:
I think it's time to get Linus' attention. The hard hang bug
is a kernel
regression. MIDI not working with ALSA is a kernel regression. Linus has
said many times that a regression is a thousand times worse than any
other bug, so if kernel devs aren't paying attention, I say it's time to
do an end-run around them and go to a higher authority.
Well, that would be the right approach if the rt patch were to be part
of the standard kernel tree. Regretfully it is not, so I doubt it would
have much effect.
I have not had the time to try to see what is going on with the hard
hangs (set up a serial console and something to receive it, etc, etc,
etc). So I have not posted on lkml about the hangs. I think you need to
have some hard data before doing that, otherwise what is the point?
But re: Practicality, is it best for now to use F8 with the 2.6.24
CCRMA
kernel? I will be building a new system in about a week, and stability
is the most important thing right now.
I guess that would be the most stable thing to run. Depending on how low
latency it is you actually need you could also run the regular Fedora
kernel on f9 or 10.
-- Fernando
Thanks for all you're doing.
David
Fernando Lopez-Lezcano wrote:
> On Mon, 2008-12-01 at 12:58 -0500, Hector Centeno wrote:
>
>> I wonder what are the latest news about the issues with the RT kernel?
>> It seems to me that all recent distros are struggling with it and I
>> remember reading some thread in LKML a few months ago. Will it be
>> possible to have a RT kernel in Fedora 10 any time soon? (I'm not
>> pressuring, just wondering about getting some info to plan my
>> upgrades).
>>
>
> The current status (for Planet CCRMA + Fedora) is as follows:
>
> The rt patches available online are:
>
> 2.6.24.7-rt21
> 2.6.26.6-rt11 (last updated October 13th)
> [http://www.kernel.org/pub/linux/kernel/projects/rt/]
>
> That hints as to the status of the rt patch :-(
> How do they interact with Fedora >= 9?
>
> 2.6.24.7-rt21: stable and the one I would use, except for the fact that
> the new X server in >= fc9 don't like something in the "old"
2.6.24
> kernel and segfault every once in a while, taking the whole session with
> it. Not usable unless you downgrade X to the one that comes with Fedora
> 8 (I tried it and that appears to work but it is not very practical).
>
> 2.6.26.6-rt11: that seems to mostly work but I have seen this kernel
> hang hard. Not very often but it happens. The big problem (other that
> the hangs) that I have with that one is that external midi interfaces
> don't work when accessed through the alsa sequencer api. So, your midi
> keyboard can't be used to control software synthesis, for example. I
> tried to tickle kernel gurus to pay attention to this one but almost
> nobody responded to my posts in lkml. One suggestion made midi input
> work but the internal timer in the alsa seq api is not working (I have
> not had time to try to get that fixed - maybe this week).
>
> You may notice there is _no_ realtime preemption patches for 2.6.27.x
> yet (and 2.6.28 is already in the rc status stage!). At least not in the
> official web site. There is a tree somewhere I tried but at least for me
> that did not result in a bootable kernel.
>
> So.... back to the original question:
>
> I could (and probably will) release a 2.6.26.x based rt kernel for fc10
> soon, with the above mentioned caveats... (so not very usable).
>
> Right now I'm just running Fedora's kernel on my fc10 test machine....
> :-(
>
> [the Fedora kernel developers are not interested in the rt patches and
> currently RedHat's GRM kernel _is_ based on 2.6.24[*], so I don't
> anticipate much change coming soon, the relevant gurus are not working
> in up to date patches AFAICT]
>
> -- Fernando
>
> PS: That's the realtime commercial offering from RedHat and presumably
> what Ingo is working on, see here:
> http://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/RHEMRG/SRPMS/
>
>
>
>
>> On Sat, Nov 29, 2008 at 2:12 PM, Steve Harris <swh(a)ecs.soton.ac.uk>
wrote:
>>
>>> I've just tried it, on a machine with with a fresh FC10 install, all
>>> seems to work fine.
>>>
>>> - Steve
>>>
>>> On 26 Nov 2008, at 22:32, Fernando Lopez-Lezcano wrote:
>>>
>>>
>>>> Well, in tune with the universe Planet CCRMA crash lands its tiny
>>>> landing craft on Fedora 10. Luckily no casualties ('cause nobody
has
>>>> tried to run it!) After a rebuild marathon there are quite a few
>>>> packages available for brave souls to test drive, and a few stragglers
>>>> still on the way.
>>>>
>>>> So far _only_ in the 'planetccrma' repository.
>>>> No planetcore packages yet[*].
>>>>
>>>> Having not tested it I can't really recommend it :-)
>>>> This shows what's there:
>>>>
>>>>
http://ccrma.stanford.edu/planetccrma/mirror/fedora/linux/planetccrma/10/...
>>>>
http://ccrma.stanford.edu/planetccrma/mirror/fedora/linux/planetccrma/10/...
>>>>
>>>> doing:
>>>>
>>>> rpm -Uvh
>>>>
http://ccrma.stanford.edu/planetccrma/mirror/fedora/linux/planetccrma/10/...
>>>>
>>>> (all in one line) should get you started...
>>>>
>>>> CAVEAT: the Jack on the Planet on fc10 is jackmp 1.9.1! It should work
>>>> fine, let me (and Stefan on the jack-devel list) know otherwise. It
>>>> should override the lame 0.109.2 that still comes with Fedora and
>>>> set up
>>>> permissions so that any user will have the right to use the realtime
>>>> scheduler (you will have to log out and login again for that to take
>>>> effect!).
>>>>
>>>> Enjoy! (if possible).
>>>> -- Fernando
>>>>
>>>> [*] the kernel situation has seen no changes...
>>>>
>
>
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>
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