I forgot to add that snd_hrtimer is used by jackd. If I turn jackd off, the snd_hrtimer module is not used:
$ lsmod | grep timer snd_hrtimer 2148 0 ## <<< not used snd_timer 17408 3 snd_hrtimer,snd_seq,snd_pcm J. --- On Sat, 11/7/09, James Warden <warj...@yahoo.com> wrote: > From: James Warden <warj...@yahoo.com> > Subject: Re: [LAD] timers > To: "Emanuel Rumpf" <xb...@web.de>, "Ralf Mardorf" > <ralf.mard...@alice-dsl.net> > Cc: linux-audio-dev@lists.linuxaudio.org > Date: Saturday, November 7, 2009, 7:34 AM > Hi guys, > > Here is what I have: > > > $ cat /proc/asound/timers > G0: system timer : 1000.000us (10000000 ticks) > G3: HR timer : 0.001us (1000000000 ticks) > Client sequencer queue 0 : running > P1-0-0: PCM playback 1-0-0 : SLAVE > P1-0-1: PCM capture 1-0-1 : SLAVE > > Ralf, you do not benefit from a high res timer. See how > much more precise the HR timer is from the output above. > Check which snd timer you have loaded: > > $ lsmod | grep timer > > snd_hrtimer > 2148 1 > snd_timer > 17408 3 snd_hrtimer,snd_seq,snd_pcm > > Of course, your h/w should have a HR timer: > > $ ll /dev/hpet > crw-rw---- 1 root audio 10, 228 2009-11-05 12:59 /dev/hpet > > you can specify the clock source to jackd: > > $ jackd --help > ... > [ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ] > ... > > > > J. > > > --- On Sat, 11/7/09, Ralf Mardorf <ralf.mard...@alice-dsl.net> > wrote: > > > From: Ralf Mardorf <ralf.mard...@alice-dsl.net> > > Subject: Re: [LAD] timers > > To: "Emanuel Rumpf" <xb...@web.de> > > Cc: linux-audio-dev@lists.linuxaudio.org > > Date: Saturday, November 7, 2009, 7:04 AM > > Emanuel Rumpf wrote: > > > Hi > > > > > > I'm confused about all the timers. > > > > > > There is: > > > - system timer > > > - hpet (high precision event timer) > > > - hr-timer (high resolution timer) > > > - rtc (real time clock) > > > - cyclic (what's that? a coded loop?) > > > - anything else ? > > > > > > > > > What is the relation of all these ? > > > Which hardware devices are actually used by those > ? > > > Which is the prefered timer for sequencing ? > hr-timer > > / rtc ? > > > > > > > If hardware is fine with Linux real-time audio, if I > > understand > > correctly, the preferred timer for MIDI sequencers is > > (should be) system > > timer at ! 1000 Hz ! For my hardware, that has got > problems > > with > > real-time audio, it's PCM playback and PCM capture. > Using > > this timers > > MIDI jitter will decrease a little bit. > > > > This is the output I get for 64 Studio 3.0-beta3: > > > > spinymouse-s...@64studio:~$ cat /proc/asound/timers > > G0: system timer : 1000.000us (10000000 ticks) > > P0-0-0: PCM playback 0-0-0 : SLAVE > > P0-0-1: PCM capture 0-0-1 : SLAVE > > Client sequencer queue 0 : stopped > > _______________________________________________ > > Linux-audio-dev mailing list > > Linux-audio-dev@lists.linuxaudio.org > > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev > > > > > > _______________________________________________ > Linux-audio-dev mailing list > Linux-audio-dev@lists.linuxaudio.org > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev > _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
