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IDProjectCategoryView StatusLast Update
0009285ardourbugspublic2023-08-09 17:00
Reporterenorrmann Assigned To 
Status newResolutionopen 
PlatformUbuntuOSLinuxOS Version(any)
Product Version7.3 
Summary0009285: Ubuntu 23.04 Cue view causes ibus daemon to use 100% cpu and system turns unresponsive
DescriptionUpgrading to Ubuntu 23.04 the version of ardour shipped with ubuntu is 7.3, if I go to cue view and add some clips and start them, ibus service goes to more than 100% cpu usage and the system becomes unresponsive. Closing ardour, ibus goes back to normal.
This happens with ardour shipped with ubuntu 23.04 AND compiling from 7.3 source on ubuntu 23.04
Binaries downloaded from doesn't have this issue
TagsNo tags attached.



2023-03-21 18:07

administrator   ~0027486

Sorry, if this does not occur with our binaries, then it's not a problem we can (or will) investigate. You would need to take it up with the Ubuntu packager(s).


2023-08-09 16:30

reporter   ~0027956

Just thought I'd add it doesn't only happen on Ubuntu. It started happening to me on Fedora 37 as well, and I can confirm it's still happening on Fedora 38 (updated today) with Ardour 7.5.0 and IBus 1.5.28. My experience seems to be a bit different, though, as closing Ardour doesn't seem to bring IBus back to normal, or at least not right away (it takes a bit). Besides, the system doesn't become entirely unresponsive: only keyboard input where you can type stuff is, and after a long time input seems to work again, but incredibly sluggish (I'm typing right now with this effect).

When I check with top (if I opened it before Ardour, otherwise I won't be able to type top in the terminal) I can see both Ardour and ibus-data taking a huge amount of CPU (0000087:0000160 and 0000102:0000120 respectively). Not sure if there's any other info I can provide, or even if this existing post is the right place to provide it.

Besides, not sure if the fault lies in Ardour, ibus, or pipewire, since it may be related to the number of connections that Ardour creates (and I have many in my templates).


2023-08-09 16:31

reporter   ~0027957

Sorry, the amount of CPU seems to have been turned into some Mantis specific code... I meant about 160 and 120 percent respectively.


2023-08-09 16:33

administrator   ~0027958

about 99.875% certain that this has nothing directly to do with Ardour, but is the fault of ibus and/or pipewire.

you can check this by running ardour with the ALSA audio/MIDI backend as a test, and see if the same thing happens. i'd wager that it does not.


2023-08-09 16:52

reporter   ~0027959

I tried configuring Ardour to use ALSA in the Audio/MIDI setup window, and it looks like it still does it. Maybe less sluggish on the input, but the high CPU on both processes is still there.


2023-08-09 16:56

administrator   ~0027960

ibus should play zero role if Ardour is using ALSA directly. So something is still wrong, but outside Ardour.

I have no idea who you can ask about this, but it's not something we're likely to investigate. If someone can provide any evidence that we're doing something wrong, we'll fix it, but I really do not believe this is the case,


2023-08-09 17:00

reporter   ~0027961

Thanks for the clarification and the prompt replies!
Just FYI, I see there's a bug open on the ibus repo (which has a link to this issue too) but no activity unfortunately:
Hopefully someone will give it a look sooner or later.

Issue History

Date Modified Username Field Change
2023-03-21 17:41 enorrmann New Issue
2023-03-21 18:07 paul Note Added: 0027486
2023-08-09 16:30 lminiero Note Added: 0027956
2023-08-09 16:31 lminiero Note Added: 0027957
2023-08-09 16:33 paul Note Added: 0027958
2023-08-09 16:52 lminiero Note Added: 0027959
2023-08-09 16:56 paul Note Added: 0027960
2023-08-09 17:00 lminiero Note Added: 0027961