Massive lag when searching files using the launcher [Performance Issue]

[Kartonrealista]

(1) Issue/Bug Description:

After typing "files ste" into the launcher it freezes for a whole minute before displaying results or allowing you to type another letter or exit the launcher. There's probably nothing special about "ste", I may just have a lot of files with that name. I assume it's looking up everything at once instead of giving up after getting enough results (it only displays seven anyways).

(2) Steps to reproduce (if you know):
Open launcher.
Type:

After a long wait I get this:

(3) Expected behavior:

It shouldn't take so long and make you unable to do anything with your system unless you wait or manage to crash it.

(4) Distribution (run cat /etc/os-release):

Pop!_OS 21.04

[chrsrns]

I also have lag on my installation while typing on the launcher. Additionally, there's a little delay before the launcher shows up when pressing the Super key.

[talhajunaidd]

The new PopOS application launcher is very slow

Following are the system details

OS: Pop!_OS 21.04 x86_64 
Host: Inspiron 3580 
Kernel: 5.11.0-7620-generic 
Uptime: 6 hours, 59 mins 
Packages: 3689 (dpkg), 52 (flatpak), 13 (snap) 
Shell: bash 5.1.4 
Resolution: 1920x1080 
DE: GNOME 
WM: Mutter 
WM Theme: Pop 
Theme: Pop-dark [GTK2/3] 
Icons: korla [GTK2/3] 
Terminal: tilix 
CPU: Intel i7-8565U (8) @ 4.600GHz 
GPU: Intel WhiskeyLake-U GT2 [UHD Graphics 620] 
GPU: AMD ATI Radeon R5 M230 / R7 M260DX / Radeon 520 Mobile 
Memory: 6311MiB / 15737MiB 

Following is the graph I generated using psrecord it when I search using the launcher it uses too much CPU which render is unusable. If I search it using application menu it's fast.

psrecord gnome-shell-pid --interval 1 --duration 30 --plot plot1.png

Happy to provide more details and dig deep.

[NathanLovato]

I can confirm the general lag when typing anything in the launcher. And can confirm one CPU's usage spikes to 100% when typing in the launcher.

Pop_OS! 2021.04, all available updates applied (July 2nd).

From System Monitor, using only the launcher:

System info:

[Kartonrealista]

It seems that the issue is resolved, so for now I'm closing it.

[NathanLovato]

It's not as bad now, but search is still pretty choppy. As in, there's no more X seconds freeze, but the UI still freezes for a fraction of a second when making a search. And one CPU usage still gets to hit 100% when typing the first few letters:

So I end up using the Applications view to open apps and do searches still for now, as it runs smoothly.

The part where multiple CPU cores engage on the right of the graph has to do with a file search.

[mmstick]

This is simply the limit of what can be done in JavaScript, on the same GJS (MozJS) process that is also running the entire desktop environment. Only by transitioning to a separated isolated Rust service will we get better performance.

[NathanLovato]

I see, thanks for the explanation!

[NathanLovato]

Following my previous comment, a new update made it much more responsive. Now there are no UI freezes anymore, it's really good. Thanks!

[talhajunaidd]

much better now.