GeopJr
Performance drop while viewing long post
Describe the bug
Lag while scrolling over a long post in feed and single post views.
Steps To Reproduce
- view post in tuba: link: https://cubhub.social/@Rusty/114669646173179239
- click show warning triangle
- scroll
Logs and/or Screenshots
no mention of any graphics issues just networking stuff
Instance Backend
Mastodon
Operating System
Linux fairphone-fp5 6.15.0 #1-postmarketos-qcom-sc7280 SMP Mon Jun 2 23:43:25 UTC 2025 aarch64 Linux
Package
OS repositories
Troubleshooting information
os: postmarketOS edge prefix: /usr flatpak: false version: 0.9.2 (production) gtk: 4.18.6 (4.18.2) libadwaita: 1.7.4 (1.7.0) libsoup: 3.6.5 (3.6.4) libgtksourceview: 5.16.0 (5.16.0) libspelling: false Clapper: false GStreamer: false
Additional Context
awesome app... performance is usually fine when scrolling but it seems this msg post was really long or just rendered differently
Can't reproduce on desktop, might be a different story on mobile but I don't have access to a device to debug this. You can try using a different renderer, try running tuba with GSK_RENDERER=ngl.
It is still slow when I run with the GSK flag. Since it is on a phone it could be my config or it could maybe just be limited processing power, although this is a relatively new phone with a decent chip (https://www.gsmarena.com/fairphone_5-12540.php)
Maybe you will notice a difference with different performance governors if you use cpupower on powersave? Your desktop might be too powerful to notice a slowdown. Is there any other advice you have?
You can also try the old gl if that's still available GSK_RENDERER=gl. I see no difference on my side with any cpu limiting software (and my desktop is actually a mid range laptop).
Is it actually the post size that's the problem? For example if you open this post do you notice the same performance issue? https://samthursfield.wordpress.com/2025/03/07/media-playback-tablet-running-gnome-and-postmarketos/ (yes it's a wordpress blog post, but if you paste it in search it will be fetched like a normal post)
When you say that it becomes laggy, do you mean as the reveal animation plays or while the post is visible? If it's the latter, it kinda reminds me of this https://gitlab.gnome.org/GNOME/gnome-software/-/issues/2172#note_2261948
My last guess is that either the custom emojis or the images might be the culprit. edit: or the hashtags at the bottom, they have been optimized on the current main branch though (#1367)
If the length is actually the issue, not that it fixes the problem really, but the next version will have long posts collapsed by default #1354
The lag kind of goes away when I am at the bottom of the post. There are a couple of emojis at the top but there are also some near the bottom. There is also some markdown at the top but I don't think it's that. Maybe it's the emojis.
I don't know how to get that link to open directly in Tuba, so instead I searched Sam Thursfield's profile and tried scrolling down on his profile page in the 'posts' section. There are posts with long text sections on this page that do not create the same laggy behavior. I notice that the difference is that the post with issues has a NSFW toggle (don't know the proper name). The posts on Thursfield's profile do not have the NSFW blocker thingy. These posts load and do not have performance issues with scrolling... even ones with emojis, markdown, and links.
To clarify, laggy scrolling means there seems to be less fps (like a laggy video game) when I scroll. It is not the reveal animation. It is the latter you described.
So I ended up searching for other NSFW content and I found another post that has the same behavior. This post was short and had just an image. I didn't even have to unblur the image. Simply clicking the show button with the triangle icon started lagging the scrolling.