Sublime Forum

ST 4092 and 4093 on Ubuntu 20.04, interface problems


I’m running ST 4093 on Ubuntu 20.04.

The whole interface halts for seconds before starting to work smoothly, and it blocks again when activating/deactivating the ST’s window, even when changing from two ST windows. Sometimes only the window title is drawn, and after a while the full window content gets rendered. It also happens while launching ST.
Same for ST 4092, but the version 4090 works fine.

Any ideas?



Could it be this issue: Sublime Text freezes on Linux (Fedora / GNOME). Which version of Gnome are you using?



It seems the same issue, but I’m not entirely sure - actually it isn’t easy to describe it exactly, maybe the users on that thread just used completely different words for the same thing or they are experiencing a different, but somehow similar, problem.

I’m using KDE Plasma 5.18.5 (Kubuntu, to be precise).

Running ST in safe mode shows the same issue.



If you’re using KDE then I doubt it’s the same issue.



I took a look at what’s changed since 4090 and there aren’t any rendering related changes. Do you see CPU spikes when those halts are happening? Are you seeing anything similar in other apps like LibreOffice?



I also noticed some lags starting a short while ago. Don’t know if it is smth related to Kubuntu or ST. When I tried to reproduce it in context of this thread I noticed it only seems to happen when a second ST window has been opened before (but the problem stays after closing it). Thus, I can not really nail it down.



I checked and yes, while blocked the ST process cpu usage goes up to 100%. Then, when the rendering completes, goes down to a regular almost 0.

The same happens on Debian running KDE Plasma 5.17.5. Also, running ST 4093 through a X network connection (yes, sometimes I do that) works fine. EDIT: No, I was wrong, though the X network connection the problem is still there.

LibreOffice Writer works fine.



Have you tried reverting to a freshly installed state?



I just tried. The problem is still there, but it is far less visibile. This seems a good hint! What else can I do?



You could try profiling the application (using gprof, callgrind or similar) to see where it’s spending those CPU cycles during the halts. A video of the issue might also help narrow things down. Do you have hardware acceleration enabled? Does changing hardware acceleration change anything?



Turning off HW acc doesn’t change it for me.

Sent you a pm with a strace file.



@clci I have no idea if this could be related, but is changing the font size with ctrl+mousewheel also deadly slow for you suddenly?



@bschaaf I sent you a private message with a link to a video.

@milkman for some reason ctrl+mousewheel doesn’t work for me (maybe I disabled it, I dont remember) but I change font size using ctrl++ or control± and in ST 4093 it is perceptibly slower compared to ST 4090, but not deadly slow.



@clci The windows changing focus like that is most likely a DE issue. My guess would be it’s also the cause of the high-cpu usage and thus the cause of the slow rendering.



With SublimeMERGE Build 2041 (coming from 2037) I see the same behavior, thus I guess it is related to some changes in S* (maybe the titlebar-stuff? idk).

Extracted From the PM Answer of you:
I learned
sudo strace -tt -s 1024 -o ~/sublime_text.trace -p <pid>
will trace IO and not CPU, could you provide a “noob” command for me to trace the CPU ? Would be helpful.

I am not sure if your suggestion “changing the GTK theme” is possible in KDE of Kubuntu (would have to dive into this), but there are no problems with GIMP (mother of all GTK Applications :wink: ). Could be a next step.

Edit: I just reverted to ST 4090 and with it works fine. Just wanted to ensure nothing else changed in the OS/…



I just reverted to ST 4090 and with it works fine. Just wanted to ensure nothing else changed in the OS/…

Thanks for confirming that. I’ve taken another look at what’s changed between 4090 and 4093 for Linux (Title bar changes were for Windows), and the only thing that’s changed is that we now restore full screen windows on startup and some tab dragging stuff on X11 - I don’t see how either of those changes could cause the problem you guys are seeing.

I’ve installed a Kubuntu VM and I don’t get the same issue. Are you able to reproduce it with a completely clean Sublime Text install (ie. after reverting to a freshly installed state) and just opening 2 windows?



Unfortunately: yes, with a newly created profile I have immediately the same behavior. Using exactly this new profile with 4090 works fine and fast as it always did.

Very odd :-/



I made a brand new installation of ST on a virtualized Kubuntu made some months ago (using VirtualBox) and I get exactly the same problems I see on my laptop. VirtualBox is running on Debian testing (if it matters, likely not).

Just to let you know. Replicating the issue on a virtualized environment is possible.



Thanks for trying.
Just noticed that ctrl+mousewheel is also quite slow on 4090, so this might be another (or no) Problem.



Not that I think it would be relevant, my Hardware is a T480 Thinkpad (i7, Full HD, including a second, currently not used GeForce MX150) with an additional FullHD screen.