On 11/10/05, thewade <pdman@xxxxxxxxxxxxxxxx> wrote: > Hello, > > I have given up on the mainstream Fedora 4 kernel and am trying to build > 2.6.14-rt5. So far I can get it built and running, but without jack it > seems. > > I am wondering what are the best settings for jack using Ingo's RT > patch: how do I make the most of the patch? > (I am trying to use CONFIG_PREEMPT_RT=y) > I use qjackctl and my .jackrc is: /usr/local/bin/jackd -u -dalsa -dhw:1 > -r48000 -p128 -n2 -m -H -M > hw:1 corresponds to the card number from /proc/asound/cards associated > with my RME Hammerfall Multiface. > > I may have to change my .asoundrc as in the mainstream kernel cards 0 > and 1 are switched for some reason (if that is what is sotpping jackd). > The only message I get is something to the effect of NTpolltime timed > out, or something... My biggest question is not how to get jackd working > - I will fix that. I am curious how to get PD running on my machine > processing complex patches but with a latency of 5.33 msec (128 frame > buffer size I think) or less. I would even settle fo 10msec (256) with > no XRUNS. > > Thank you all for your help! > -thewade > Hi, A few comments: 1) The current kernel from Ingo would be 2.4.16-rt9. I think that rt5 didn;t last very long and had some problems. Please try -rt9. 2) Make sure you reinstall the realtime-lsm package after building that kernel. 3) Make sure you create a realtime group and modprobe realtime to enable that group: modprobe realtime gid=600 any=1 where gid=600 is for my realtime group in /etc/groups. 4) Making best use of the kernel requires that you understand the ISR number for your sound card and reset it's priority higher. This helps a lot in reducing or eliminating xruns. 5) Remove .jackrc completely and let your system set a new one. 6) Here are my HDSP 9652 settings: jackd -R -p 64 -d alsa -r 44100 -p 64 -n2 -d hw:1,0 I get a few xruns at -p 64 -n2. I get none at -p 256 -n 2. I am still looking for the root cause of the few xruns I get at 64/2. 7) Make sure you have the Jack FIFOS mounted on tmpfs. As a comment, I don't personally like Jack in /usr local. You might consider rebuilding Jack one of these days with: ./configure --prefix=/usr Hope this all helps a bit,. Cheers, Mark
