CPU at 100% in menu in Vulkan on Linux

[hrydgard]

As it says on the tin.

Reported to happen on NVIDIA by KickMeElmo on the discord.

[foxsevent]

Small clarification, it's not just in menus but everywhere at all times with the Vulcan backend, menus and games, a CPU core is being pushed to 100%, which core it is can switch while running.
This is on Steam Deck Linux AMD APU.
https://ibb.co/58wN3Xy
https://ibb.co/8jzJRhv

Like @foxsevent said, it's on the menu of PPSSPP AND also in game, tested with Tekken 6, Medal Of Honor Heroes and PES 6, one core is locked at 100% for no apparent reason and the core used can change at any time.
The issue only happens with the native PPSSPP Vulkan renderer, I'm on Linux and it didn't happen when using the OpenGL renderer with the Zink driver(Zink is a translator that translate OpenGL calls to Vulkan).

Here is my specs and PPSSPP info :
CPU : Ryzen 7 7840HS 8C/16T 5.1GHz.
RAM : 64GB DDR5 4800MHz.
GPU : Radeon 780M 4GB VRAM set in UEFI.
OS : openSUSE Tumbleweed Linux, kernel version : 6.8.9.
PPSSPP Version : latest git revision, self compiled with Clang 18.1.5 and lld as the linker.
PPSSPP CPU Backend : IR Interpreter.
PPSSPP Render Resolution 4X (1080p).

[PhantomX]

Starts after Some renaming, add a bunch of sanity debug-asserts .

[hrydgard]

Thanks, that's interesting!

[hrydgard]

Hm, in my testing, I'm seeing 100% CPU in commits before that one. I'll bisect myself (maybe it's a different cause..)

[hrydgard]

Alright, I've figured this out as far as I can tell. When I switched the SDL build to run independently of the message pump in Vulkan mode, I forgot to switch from SDL_PollEvent to SDL_WaitEvent. So without being throttled by rendering, it'll just spin.

There seems to be some differences in behavior to iron out but once that's done, this will be fixed.

The starting commit mentioned by PhantomX above doesn't seem to have anything to do with it..