Performance drawback

[TyKonKet]

With the latest versions I noticed a performance issue, I usually work with a large Lua workspace (more than 850 source files), before that issue the workspace diagnostics used to load up in less then 3 minutes or so.
Now with the latest version it takes never less then 2-3 hours to complete the diagnostic analysis.
I'm pretty sure it's an issue introduced with latest versions because when i rolled back the VSCode extension to version 1.20.1 the issue disappeared and diagnostics started back to load in 2-3 minutes.

Environment:

• OS: Windows
• Is WSL remote? No.
• Client: VSCode

[sumneko]

Did you use generics in your project?

[TyKonKet]

No, also the project isn't currently fully EmmyLua documented, most of files are still "plain lua".
One more info that may help you is that when the diagnostics runs fine, the project have zero errors and warnings.

[TyKonKet]

Tested now with 1.20.3, but it's still very slow, seems that the issue exists both with 1.20.2 and 1.20.3

[mcb5637]

I noticed this too, and maybe this helps: When it hangs on diagnosis, there were a lot of notifications, that VS Code is currently running diagnosis on one file. Maybe the previous diagnosis doesnt get stopped when a new one starts?

[b0kker]

Can confirm what @mcb5637 said: https://i.imgur.com/rn5LfU4.mp4

[sumneko]

I noticed this too, and maybe this helps: When it hangs on diagnosis, there were a lot of notifications, that VS Code is currently running diagnosis on one file. Maybe the previous diagnosis doesnt get stopped when a new one starts?

It seems that the previous diagnosis task has fallen into an endless loop, so that it cannot handle the signal to stop the diagnosis.

[Nelvin]

Same issue here, also while this happens, the language server uses a lot of memory - usually 3-5GB but sometimes even more than 10GB.

[WuJiayiSH]

looks like diagnosis takes much longer since 1.20.2 than 1.20.1

[WuJiayiSH]

might be caused by duplicated meta files, I have a copy of meta/3rd/cocos4.0 folder in my project, it doesn't happen when I remove it

[Nelvin]

I don't have any meta folder in my project (it's a game using the Löve framework).

My guess at the moment is, that it might be caused by big files as one of my Lua files I do a lot of work in, is ~15k lines. Maybe it's just a kind of race condition in such situations ... but that's also just a guess.

[oblitum]

I just reported a similar experience here.

EDIT

I just figured out that when using lua-dev if I do:

local lua_settings = require('lua-dev').setup().settings.Lua
lua_settings.workspace.library = require('lua-dev.sumneko').library()
lua_settings.workspace.library['/usr/share/nvim/runtime'] = nil
vim.fn['coc#config']('Lua', lua_settings)

Everything becomes snappy. The key was to remove '/usr/share/nvim/runtime' from workspace.library. (cc @folke)

[akinsho]

FWIW I also observed the same behaviour and so disabled the runtime options, I still saw quite high CPU usage so I disabled the plugins as well. For more context for non-neovim users both these settings can add several hundred files to library for sumneko. Which I think it currently handles quite poorly i.e. very high CPU usage

[folke]

@oblitum @akinsho I was still running 1.20.1 and with that version everything runs very smoothly.

Just upgraded and sumneko is totally unusable.