Excessive memory usage with clangd 19

[TobiasBohnen]

Clangd-19's memory usage is at about 1GB on startup and steadily grows with each file opened, eventually reaching 8GB before crashing.
In my tests, version 18.1.8 peaks around 1GB, and typically idles at about 500MB.

Logs
clangdlog.txt

System information
clangd version: 19.1.3
clangd extension version: 0.1.29
Operating system: Windows 10

[HighCommander4]

Are you able to share a code example on which a difference in memory usage can be observed?

[TobiasBohnen]

I get this behavior even with a nearly empty project, although to a lesser extent:
https://github.com/TobiasBohnen/test

v19: ~150MB on startup, increases by ~1MB if I close and reopen 'main.cpp'
v18: ~13MB on startup, increases by ~100KB

[Lev275568]

I have same for:

• clangd version 19.1.5
• Ubuntu 24.04.1 LTS
• llvm-vs-code-extensions.vscode-clangd 0.1.33

clangd command line parameter "--malloc-trim" helps to drop from 8000MB to 1600MB after changing file in IDE and after 1 minute.

[Lev275568]

In my case, switching to tcmalloc for clangd decreased memory consumption about 30%
sudo apt install google-perftools for tcmalloc
LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libtcmalloc.so.4 clangd

Also I've found that clangd creates additional thread for each opened vscode tab and this thread does not honor "-j" command line parameter. So, if there are a lot of tabs, and some common header file is changed, then clangd consumes a lot of memory (because is not honor?).

Related clice-project/clice#5