On Saturday 21 July 2007, Atte André Jensen wrote: > > Which kernel version is this? > > Homemade (with mingo rt-patch) 2.6.18-rt7 > > 2.6.20-16-lowlatency The lowlatency kernel of ubuntu is not a realtime kernel. And for your home made kernel, please let us see your .config e.g. ~$ grep PREEMPT /boot/config-$(uname -r) # CONFIG_PREEMPT_NONE is not set # CONFIG_PREEMPT_VOLUNTARY is not set # CONFIG_PREEMPT_DESKTOP is not set CONFIG_PREEMPT_RT=y ^^^^^^^^^^^^^^^ CONFIG_PREEMPT=y CONFIG_PREEMPT_SOFTIRQS=y CONFIG_PREEMPT_HARDIRQS=y CONFIG_PREEMPT_BKL=y CONFIG_PREEMPT_RCU=y # CONFIG_DEBUG_PREEMPT is not set # CONFIG_CRITICAL_PREEMPT_TIMING is not set I underlined the relevant line there > > > On Debian, I get ksoftirqd as well, one > > per processor core. ksoftirqd is part of the 2.6 kernel series. I > > imagine you're still using a 2.4 kernel on your Debian system, > > Nope... > > > or the > > kernel is configured and built differently to mine. > > Might be... > > > It may be possible to rebuild the Ubuntu kernel you are using to match > > what you are used to, but I don't know if that will get you what you > > want. > > I grabbed a vanilla 2.6.22.1 and applied the latest patch and quick > testing seems to suggest that the system is running at least at well as > under debian: > > atte@ajstrup:~$ uname -r > 2.6.22.1-rt4 > > atte@ajstrup:~$ ps aux | grep IRQ > root 36 0.0 0.0 0 0 ? S< 18:15 0:00 [IRQ-9] > root 268 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-4] > root 292 0.0 0.0 0 0 ? S< 18:16 0:00 > [IRQ-12] > root 293 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-1] > root 1108 0.0 0.0 0 0 ? S< 18:16 0:00 > [IRQ-14] > root 1139 0.0 0.0 0 0 ? S< 18:16 0:00 > [IRQ-15] > root 1140 0.2 0.0 0 0 ? S< 18:16 0:02 > [IRQ-11] > root 1936 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-8] > root 2025 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-7] > root 2103 0.3 0.0 0 0 ? S< 18:16 0:03 > [IRQ-10] > root 3432 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-3] > atte 4674 0.0 0.0 2888 772 pts/2 R+ 18:33 0:00 grep > IRQ > > > I've never tried setting real-time priority on kernel threads > > like that, and I don't know if it would achieve anything. I trust it > > did for you? > > Alot! > > Bottom line: It seems it's still necessary to roll your own kernel to > get optimal realtime performance under ubuntu :-( -- Palimm Palimm! http://tapas.affenbande.org _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
