frequent tiny jackd xruns (x86_64) since 2.6.28 kernel

[Cezary Baginski]

Binary package hint: linux-image-2.6.28-11-generic

TESTED:
- Jackd worked for me in Hardy Desktop x86_64 until updated to a recent kernel (incredibly large xruns - x86-64 arch-specific jack bug?)
- jackd works fine on hardy (2.6.27-14-generic) on eeepc (i386)

PROBLEM:
Fresh install: Jaunty 9.04 Desktop (x86_64) on same PC as the Hardy mentioned gives regular and frequent xruns (4-15 per second, depending on jack settings, ~ 0.02 msecs each)
- playing sound of course gives tiny bits (msecs) of sound from the original stream

EXPECTED BEHAVIOR:
- jackd should at least not have xruns when not playing anything

HOW TO REPRODUCE:
- disable/kill pulseaudio
- jackd -d alsa .... (almost any combination of options give the same effect, w/wo realtime, etc)
- spits out many tiny xruns
- this is with _no_ playback - just jackd running

OTHER TESTS:
- same thing on both 2.6.28-11-generic and 2.6.28-3-rt (x86_64) - jackd version: 0.116.1-3ubuntu3
- same thing without X running, disabled services
- did not check Ubuntu Studio x86_64 yet, nor did I check i386 ...

INFO:
- I used "ubuntu-proposed" repositories for both Hardy and Jaunty
- limits.conf setup correctly for rtprio, memory locking, nice (@audio)
- pulse is installed, but I renamed pulseaudio binary to prevent it from loading

HARDWARE:
- lspci: onboard nVidia MCP51 AC97 Audio Controller (snd_intel8x0)
- /proc/interrupts shows sata_nv and Intel ICH on same irq
- AMD Sempron 2500+, 2GB RAM, 2x SATA HD, onboard GeForce6100

Questions:
- anything else I can attach/test/tryout that would be helpful?
- any specific kernel I should check? (from PPA or build specific version?)

Sorry if this issue is well know or a duplicate of another bug - I couldn't find anything similar or relevant.

The last idea I have: get latest vanilla kernel and jack sources - and try to debug the problem myself - any suggestions would be helpful, thanks.

[Jeremy Foshee (jeremyfoshee)]

Hi zatoichi0,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/lucid.

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 366884

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Jeremy Foshee (jeremyfoshee)]

This bug report was marked as Incomplete and has not had any updated comments for quite some time. As a result this bug is being closed. Please reopen if this is still an issue in the current Ubuntu release http://www.ubuntu.com/getubuntu/download . Also, please be sure to provide any requested information that may have been missing. To reopen the bug, click on the current status under the Status column and change the status back to "New". Thanks.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Cezary Baginski (cezary0)]

Hardware upgrade (new PC) seemed to solve the problem.