Anyone else having problems with dropouts and X-runs since a recent kernel update?

[RyanH]

Just in the last day I have started getting crazy x-runs - not even while recording anything, just playing a song in QTractor. I have closed everything, shut down the computer and started everything up again, to no avail.

This is the same song I've been working on for months with no issues. Same plugins and synths (Yoshimi x2, run as stand-alone) using the same settings, same DAW (QTractor), about the same number of tracks being played at once, same Jack settings. I have added one track and a couple of small MIDI edits in the last day, but nothing huge, and I opened an earlier version of the file from a few days ago and it's now giving me the same problem.

One thing I think I have noticed - but could be imagining it - is that, as I save more and more versions of this project, they seem to save more and more slowly, and also open more slowly, AND the fan seems to run harder and harder. I'm saving them as the zipped .qtz files, though, so I would think each new one would be completely distinct from the others and therefore not affect anything. Is there some way I'm gunking things up under the hood?

The system monitor shows I'm only using 1.5 of my 19.3 GB RAM, zero swap, CPU load 4%.

I think I updated my system two or three days ago, and if memory serves, it was only a kernel update (no software). But as I said the x-runs only started today, so aren't the immediate result of the update (I've worked on the song nearly every day since).

I'm using Ubuntu Studio installed over Kubuntu. If it's relevant, my system info is...

Operating System: Kubuntu 20.04
KDE Plasma Version: 5.18.8
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Kernel Version: 5.4.0-124-lowlatency
OS Type: 64-bit
Processors: 8 × Intel® Core™ i5-1035G1 CPU @ 1.00GHz
Memory: 19.3 GiB of RAM

... but as I said, nothing has changed since the glory days when everything was working smoothly.

Any thoughts?

[rncbc]

and what about qtractor version and package source?...
environmental jack settings might have changed though, are you sure you're on genuine jack or under pipewire substitution as is the new craze?

[RyanH]

and what about qtractor version and package source?...
environmental jack settings might have changed though, are you sure you're on genuine jack or under pipewire substitution as is the new craze?

Haha, no, no Pipewire. I'm still using Ubuntu Studio/Kubuntu 20.04, waiting to update to the the latest LTS (which will happen in the next couple of weeks). The QTractor version is 0.9.12, which is what came with my distro a couple of years ago. I know you gave me a link to your PPA in another thread, but I figured I would wait and just update the whole distro to avoid a lot of tinkering.

I'm pretty sure this isn't a QTractor issue and have changed the title of the post to remove that reference. I think it's a kernel issue. My reason for thinking that is that I have another laptop with the exact same setup and which also got the kernel update. The night before I had this x-runs issue on this computer, I had some audio dropouts on the other laptop while recording a single audio track in Audacity.

If you're interested to know, I figured out today that most of the x-runs happen when the automation in one of my midi tracks triggers tunnel reverb in Yoshimi, which was not an issue before. And the x-runs are more likely to happen when I have more things connected in Jack - for example when I use Carla to host a second reverb plugin, or when I have a second sound card plugged in.

[RyanH]

Rncbc, I have a question which might have nothing to do with anything...

Looking at my system monitor, I noticed a couple of "baloo" entries (baloo_file, baloorunner). I didn't know what this was so looked it up and some people thought it was using too much system resources and said it could be disabled without causing any problems. Seems like it's used for some types of searching which I don't use. I was going to try to see if disabling it made a difference but first wanted to know: does QTractor use the baloo file for anything? I don't want to make things worse.

[bluzee]

I suppose the simplest thing to try if you have not deleted the previous kernel yet is to reboot to the older kernel and see if the problem resolves.

[rncbc]

does QTractor use the baloo file for anything?

nope. baloo is part of the kde framework, you may disable it anytime on system settings / search

cheers

[sunrat]

Baloo is KDE file indexing service. Disable it! System Settings > Search > File Search, untick "Enable File Search"

Snap @rncbc

[RyanH]

Baloo is KDE file indexing service. Disable it! System Settings > Search > File Search, untick "Enable File Search"

Snap @rncbc

Haha, love the enthusiasm! How can I resist now?

[RyanH]

does QTractor use the baloo file for anything?

nope. baloo is part of the kde framework, you may disable it anytime on system settings / search

cheers

Perfect, thanks!

[RyanH]

Thanks, Bluzee. I had to give my head a "doh" smack. Someone in another forum also mentioned booting into an earlier kernel, which I totally forgot was an option. I guess it's a testament to the reliability of Linux that that's something I've only had to do once or twice before.

So I booted into the previous kernel and everything worked normally. Then back into the current kernel, and lo! everything seems as it should be. So not sure if maybe booting into the earlier kernel reset something or what. Either way, I'm happy to be back working on my song. Fingers crossed that the issue is gone for good.

Cheers all.