I actually get very very well latency in the 2.6.3-rc3 kernel... its the only 2.6 kernel i have used so far... and on the 2.4.23 kernel that is patched with low-latency has xrun saying 400+- ms which is crazy... and ll is turned on for sure... for 2.6 the highest i get is around 20 ms. but i am also running fluxbox which uses very little cpu.. my machine is a intel celron 533MHz with 256mb RAM with gentoo installed :) -- Marko Dimiskovski > Hi, > > torsdagen den 27 maj 2004 19.16 skrev cv223@xxxxxxxxxxx: > > So, based on Fernando's and Malcolm's advice, I decided to quit fussing > > with the 2.6 kernels and stick with the 2.4.23 that I have working to do > > some recording last night. The band came over - we were set and ready to > > go. I hit 'record' to get an idea of the drum mix (we're submixing to > > stereo) - 3 seconds in, Ardour stops with an 80ms xrun! Arrgh! I sweated > > through the rest of the evening, fearing another occurence at 3:30 into a > > 4:00 song. Fortunately, everything went ok. > > > > I guess I'm back to trying to figure out what's causing these long xruns, > > now under the 2.4.23 kernel. > > > > Do most people shut off non-essential daemons during recording sessions, or > > do any other tricks? This is kinda frustrating, as the CPU load seems > > rather low (< 15% when the xrun happened). I guess I'll test out reiserfs > > and even ext2 to see if the filesystem is the culprit. > > I actually run fullblown KDE most of the time, it works pretty well at 512x2, > I can run 256x2 but xruns get more frequent, but not unbearably so. I'm > mainly running MusE and I seldom get kicked out, but it does happen... > > There has been talk on the Jack list from time to time about adding a mode > where you won't get kicked out so easily even if Jack misses a beat. > For developing jack I think the current approach is good, the audio equivalent > of an assert, but for real usage it is a little hard on the user. Especially > if you are doing a performance, then it's devastating. > > To return to the subject, I hear others use lightweight window managers and do > stop all unnesesary services to get better stability, if you have problems it > will probably help. > > /Robert > > > > > Thanks for reading the ramble, > > > > Joel > > > > > > I guess my main motivation for trying out the 2.6 kernel is laziness. > > > > Just build the kernel and get the performance and ALSA without patches > > > > or compiling extra stuff. At least, that was _supposed_ to be the way > > > > it worked! I'll keep trying the new kernels, but keep the old faithful > > > > 2.4 kernel around for recording. > > > > > > > > I'm _still_ curious about what causes the long xruns, though. > > > > > > New versions of alsa can be compiled with the "--debug=full" option (I > > > don't think the current code in the kernel has that). That will enable > > > you to tweak a proc variable to dump the kernel stack on each xrun, it > > > is something like /proc/asound/card0/pcm0p/xrun_debug (for playback, > > > same for recording in pcm0c). "echo "2">/proc/.../xrun_debug" will turn > > > reporting on. You will get the stack traces in /var/log/messages. > > > > > > Not that you will immediately know exactly what has to be done to get it > > > fixed, of course :-) > > > > > > IMHO stick with 2.4.x, in my tests 2.6.x is not even close to being > > > ready for pro audio work. It will get better but it will take some time. > > > > > > -- Fernando > > -- > http://spamatica.se/music/
