Okay, looked at it some more. When RT is enabled, jack just locks up
and the watchdog terminates the process, regardless of the buffer
size. When RT is disabled the xruns are allowed to continue, and the
number of xruns decreases with a higher buffer size (but never go
below about 10/second). There's no evidence that RT mode has failed to
be set. This is all as root.
I am using the proprietary NVIDIA drivers, as gotten from the Ubuntu
repositories. I would be surprised if this had anything to do with it
though, since direct alsa works fine with the same xOrg drivers.
Unless, of course, there's some software conflict between the video
drivers and jack itself (as opposed to there being a hardware-level
conflict).
hmm....
thanks for the advice.
-Ian
On 6/13/06, Lee Revell <rlrevell(a)joe-job.com> wrote:
On Tue, 2006-06-13 at 16:17 -0400, I. E.
Smith-Heisters wrote:
I've futzed around a bit more. I'd done
this before, but I'd forgotten
the exact results except that it didn't work. Tried all this both with
and without RT and 16bit mode forced:
upping frames/period to 4096 reduces the number of xruns to several/second.
upping periods/buffer to 3 still gives xruns, as well as "usecs
exceeds estimated spare time" messages.
upping periods/buffer to 4 makes initialization fail with "ALSA: got
smaller periods 2 than 4 for playback"
putting it into non-duplex (ie. playback only) has no effect on behavior.
So, yeah, that's why it's mysterious. In the past I sacrifice latency
for no xruns, and everything's dandy. Not so, this time...
Thanks for the suggestions.
Are you saying that RT mode has no effect on the xruns? I find this
hard to believe.
Check the messages from JACK - maybe it's failing to set RT mode (thisis
a bug that's fixed in the development tree).
Try these tests in RT mode as root to be sure.
Are you using the proprietary ATI or Nvidia drivers?
Lee