I cannot reproduce. Also, the download link to the json file is invalid, you need to pass ?raw=true.

Note that garbage collection takes some time until unused text models are cleaned up.
I cannot explain why there are some text models kept alive even if all editors are closed, but even after opening hundreds of files, there are at most two such hanging (and disposed) text models. These text models no longer keep the text buffer alive.

I think a text model that is being disposed when you close an editor is immediately freed from memory if there are no more references. But one thing I remember is that when an extension resolves a text document for any reason, we only free up such a reference after a certain timeout because there is no API to release the use of a text model. So maybe retry with extensions disabled.

@cynecx I also tried, but failed to reproduce the leakage. However, while investigating I ran into #143111 and #143112 .

In the past, in order to be overly careful, when a TextModel gets disposed I've added that we swap its text buffer with an empty one. This helps to minimize the effect in those rare cases where a reference to a disposed TextModel lingers somewhere.

Looking at your screenshot, I see that there is a reference via v8's deoptimization data left to a disposed TextModel. While we cannot control how v8 functions, we can try to be even more protective. Again, from your screenshot, it looks that TextModel._bufferDisposable still ends up referencing the text buffer and we can also manually remove that reference as part of being overly careful.

@alexdima 120318d seems to have fixed this. I can't seem to reproduce this on the latest insiders. Thanks!