explorer.exe process spam with the testing ntsync version

[papaj-na-wrotkach]

I was trying to use the testing ntsync version from releases.
https://share.cachyos.org/proton/proton-cachyos-10.0-20250714-ntsync-slr.tar.xz

I set it up as the default compatibility tool. After restarting Steam, my RAM usage was increasing constantly because of a huge amount of explorer.exe /desktop processes.

proton-cachyos package from cachyos-v3 repo does not have this issue. After setting the default tool to that version and restarting Steam I was able to play the game (HELLDIVERS 2). After overriding the compatibility tool for the game to the ntsync testing version and launching the game the explorer.exe processes again hog all of my RAM.

This seems similar to an old issue I encountered a long time ago on a different Linux system.

Similar issues:
ValveSoftware/steam-for-linux#8255
ValveSoftware/steam-for-linux#8114

[loathingKernel]

There have been a few people that reported increased memory usage in the form of memory leaks, this might be a step towards identifying the issue. That being said I have not encountered it while using either the regular or the ntsync builds, so I don't know how to poke at the issue at this point to further see what is going on on my own. I will keep an eye out still.

[loathingKernel]

In the past few versions, I've imported a few changes from upstream Wine regarding ntsync, please re-test.

[papaj-na-wrotkach]

I tried testing with both wine-cachyos and wine-cachyos-slr from package manager as they already have built-in NTSync support.

After setting as the default compatibility tool and relaunching Steam there is only one explorer.exe process at most. The process spawns and terminates a few times but I think that's normal. After launching a game with PROTON_USE_NTSYNC=1 one explorer.exe process remains until I close the game.

I believe the problem is fixed now. Feel free to close this issue if you also think so.

[loathingKernel]

I see, thanks for re-testing. I'll keep it open for a little while more just to keep track of it.