Yes, That's what i see when i type uname -a : Linux melinda 2.6.18.8-86 #2 SMP Mon Feb 11 00:50:59 EET 2008 i686 mobile AMD Athlon(tm) XP-M 2200+ GNU/Linux So it looks like i don't have realtime support. But i can use any audio application without having any xruns or latencies. I changed my /etc/security/limits.conf file as: @audio - rtprio 95 @audio - memlock 512000 @audio - nice -19 and it works ok. On Tue, Mar 18, 2008 at 7:55 PM, Asmo Koskinen <asmo.koskinen(a)arkki.info> wrote: -- Arda EDEN Cumhuriyet University Faculty of Fine Arts Department of Music Technology Sivas/TURKEY

On Tue, Mar 18, 2008 at 11:25 AM, Arda Eden <ardaeden(a)gmail.com> wrote: It is not possible to use ANY kernel with NO latencies. EVERY kernel has latencies. The question is how low do you want the latencies to be? If you can exist with 50mS or higher you might get away with a standard kernel. If you want to run with 1.2mS latency then you will absolutely have to have a real-time enabled kernel.

So what does a realtime kernel change ? Makes my latency 1 ms ?

Am Dienstag, 18. März 2008 schrieb Fons Adriaensen: Unfortunately this comes at a price: During development it is way easier to lock your system when you use an rt kernel. Because the amoc-running process with realtime-priority gets all the processing time it wants, it can be _very_ hard to get the system to react to keyboard/mouse or network-ssh to get it back under control... Of course this isn't really an issue for the mere user.

On Tue, Mar 18, 2008 at 11:41 AM, Arda Eden <ardaeden(a)gmail.com> wrote: wrote: wrote: use Absolutely. The most recent kernels are often quite good. However I would say that the difference between a standard kernel running 5mS and a RT kernel running 5mS is that the RT kernel is far more likely to meet the 5mS requirement under heavy system loads while the standard kernel may, at times, give a bit too much time to non-rt threads and not get back to your audio thread as fast as someone might want. If you want the highest reliability means of meeting your RT requirements all the time then use the RT kernel. If you are just doing home recording and can accept an occasional xrun (i.e. - a glitch in the recorded data) then stick with the standard kernel for as long as it works for you. Just my view, Mark

That kernel is getting pretty old. I'm running 2.6.24-rt1 here. you might want to check out the RT-Wiki or some of the sites for using RT kernels with audio apps. http://rt.wiki.kernel.org/index.php/Main_Page The above link gives instructions for patching a kernel to get to an RT kernel. Hope this helps, Mark On Tue, Mar 18, 2008 at 12:02 PM, Arda Eden <ardaeden(a)gmail.com> wrote: mobile wrote: wrote: to kernel to a will a

There is really no reason that I know of that you cannot build this kernel yourself. It's not horribly difficult once you've done it a few times. It can be quite daunting when you're up to bat for the first time though. the trick is understanding what driver modules you are using and making sure all of those are included in the configuration of your new kernel. Once you get past that step it's just a matter of adding a new option in the grub config file and trying it out. From the RTWiki these are the commands to download and patch a kernel: # wget ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-2.6.23.1.tar.bz2 # wget http://www.kernel.org/pub/linux/kernel/projects/rt/patch-2.6.23.1-rt11.bz2 # tar xfj linux-2.6.23.1.tar.bz2 # cd linux-2.6.23.1 # bzcat2 ../patch-2.6.23.1-rt11.bz2 | patch -p1 The above is for 2.6.23. If you were going to do it you might as well go for 2.6.24. Changing the kernel itself should not cause any changes in the stability of your applications. They really exist at a higher level and just talk to the kernel underneath it. If a new minor revision kernel upgrade breaks an application I think it would generally be considered a regression in the kernel and would get fixed. I have kernels ranging back to 2.6.14. they all work. Hope this helps, Mark On Tue, Mar 18, 2008 at 12:41 PM, Arda Eden <ardaeden(a)gmail.com> wrote: don't ? wrote: RT wrote: ardaeden(a)gmail.com> order EVERY latencies with you without I 5mS likely might for

On Tue, Mar 18, 2008 at 3:36 PM, Arda Eden <ardaeden(a)gmail.com> wrote: EET Congrats! So that appears tobe a release candidate kernel from some months ago. None the less I ran some 2.6.24_rc8 kernels for awhile on AMD64 and had no problems. No big deal but when you get around to it you might want to get on the stable kernel just to make sure you're not effected by any last minute changes they made. Excellent work! let us know how it works out. Cheers, Mark

On Tue, Mar 18, 2008 at 11:25 AM, Arda Eden <ardaeden(a)gmail.com> wrote: linux It is not possible to use ANY kernel with NO latencies. EVERY kernel has latencies. The question is how low do you want the latencies to be? If you can exist with 50mS or higher you might get away with a standard kernel. If you want to run with 1.2mS latency then you will absolutely have to have a real-time enabled kernel. xruns are just an indication of the system not meeting the latency requirement you set in Jack, i.e. - a by product of how you answered the question in the first paragraph. - Mark

"Arda Eden" <ardaeden(a)gmail.com> writes: Looking at the name of the kernel is not a good idea;). zcat /proc/config.gz | grep CONFIG_PREEMPT_RT