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IDProjectCategoryView StatusLast Update
0009568ardourbugspublic2023-12-13 17:46
Reporterautomaciej Assigned To 
Status newResolutionopen 
PlatformDebian GNUOSLinuxOS Version(any)
Product Version8.1 
Summary0009568: Slow operations on markers
DescriptionInitially discussed in

A session with 0000010:0000030 regions and 0000102:0000120 markers is slow to make operations on markers.

Slow operations:
Session load
Opening the side panel with the list of markers (shift+L)
Adding / removing markers
Steps To ReproduceImport/open the attached session. Open the side panel (shift+L). Try adding a marker and/or removing a marker.

Expected: Operation is near instantaneous.

Observed: There's a spike in CPU usage / one saturated core, for a good few seconds. The desktop opes a dialog saying that Ardour is not responding and asking if I want to force-quit or wait.
Additional InformationArdour generally works, and it's enough to wait for the marker to be created or removed.

I couldn't reproduce the issue by creating a new session and tapping Tab 120 times.
The issue remained after I removed all the tracks and all the audio sources from the session.
I couldn't pinpoint what exactly about the markers and/or regions makes them slow, because the slowness built up gradually over time. But the slowness is persistent, and I verified that does persist in the session archive I'm uploading.



2023-12-07 17:59



2023-12-08 16:44

administrator   ~0028400

Thanks for the session. That helped to track down the issue.
The Slowdown problem is now fixed since Ardour 8.1.156. It was caused by a significant amount of Section and Location Markers.

There is still an issue with your session when undoing a marker change. That apparently results in an endless loop.


2023-12-09 15:47

reporter   ~0028402

I downloaded Ardour-8.1.164 and I can confirm that adding and removing markers are now fast. Thank you!

I'll avoid undoing marker changes for now.


2023-12-09 21:57

reporter   ~0028403

I worked some more using Ardour 8.1.164.

- Loading the session is much faster
- Adding and removing markers is fast just like in an new/empty session
- Opening the markers pane (shift+L) is still slow
- Undoing a marker change is indeed still slow and/or maybe doesn't even work at all, I'm not sure. I realized that I can't avoid undoing marker changes - if I work with markers, and I need to undo a sequence of steps, there's no way other than trying to undo a marker change. Today I tried to undo a chance, I eventually gave up on the undo and instead used an earlier saved session and redid a small amount of work.


2023-12-10 03:48

administrator   ~0028404

It helps significantly if you never show the Location list or the sidebar. Then undo/redo works just fine.

Once the location UI and/or the sidebar version is shown, here, it can take up to 15 sec here with your session to re-populate that pane.


2023-12-13 13:40

reporter   ~0028415

The location UI is important to my workflow, I use it to navigate around the session. But fortunately I don't use the undo option too often, and I try to separate the times when I work with markers (which don't need undo generally) and when I work with regions (where I need to undo quite often).

I'm wonder what is it about my session that is a challenge for Ardour? It's not like it's millions of markers or millions of regions. Is it about some sort of relationship between the two?


2023-12-13 17:46

administrator   ~0028416

It's just that GTK performance sucks if there are more than 64 elements in a box - It's entirely a GUI issue.
undo/redo restores the whole state and if locations were added/removed the LocationUI is repopuplated, which can take ages.

Perhaps use the mini-timeline at the top to navigate?

I've checked with a few thousand locations and everything's fine as long as I never show the Location List, and I don't see a way to fix the UI performance of that right now.

Issue History

Date Modified Username Field Change
2023-12-07 17:59 automaciej New Issue
2023-12-07 17:59 automaciej Tag Attached: performance
2023-12-07 17:59 automaciej File Added: Slow markers repro.ardour-session-archive
2023-12-08 16:17 x42 Assigned To => x42
2023-12-08 16:17 x42 Status new => assigned
2023-12-08 16:44 x42 Note Added: 0028400
2023-12-09 15:47 automaciej Note Added: 0028402
2023-12-09 21:57 automaciej Note Added: 0028403
2023-12-10 03:48 x42 Note Added: 0028404
2023-12-13 13:40 automaciej Note Added: 0028415
2023-12-13 17:46 x42 Note Added: 0028416
2023-12-13 17:46 x42 Assigned To x42 =>
2023-12-13 17:46 x42 Status assigned => new