08302: BGFX using all cpu cores even not being rendered any graphics onscreen

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
08302	Graphics	Major	Always	Apr 24, 2022, 20:15	May 16, 2022, 23:20

Tester	Augusto	View Status	Public	Platform	SDLMAME
Assigned To		Resolution	No change required	OS	Linux (64-bit)
Status [?]	Closed			Driver
Version	0.242	Fixed in Version		Build	64-bit
		Fixed in Git Commit		Github Pull Request #

Summary	08302: BGFX using all cpu cores even not being rendered any graphics onscreen
Description	Ubuntu 20.04.3 totally updated in current date using kernel 5.17 FX-6300 3.5 GHz 6 cores and nvidia driver 470 GT 640 1 GB. Using SDLMAME 0.242. If BGFX is selected when mame is being started in main game select GUI even only rendering an simple list of games is being used all cpus cores and less of 10 % GPU usage at point not is possible start any game in 100 % speed. That problem happen if selecting both backend opengl or vulkan. If selecting instead opengl return the normal mame speed. That problem also is happening in windows or only in Linux ? Thanks for read and have an nice week.
Steps To Reproduce
Additional Information
Github Commit

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Regression Version
Affected Sets / Systems

Attached Files	WindowOpenGL.png (112,430 bytes) May 7, 2022, 03:41 Uploaded by ozfalcon
	WindowUIVulcan.png (289,154 bytes) May 7, 2022, 03:41 Uploaded by ozfalcon
	WindowVulcan.png (111,627 bytes) May 7, 2022, 03:42 Uploaded by ozfalcon

No.20089 Tafoid Administrator Apr 25, 2022, 11:02	With some quick testing of -video bgfx in Windows and watching processor performance, I don't see any type of excessive CPU use when navigating menu in a -window compared to d3d or opengl. I'd have to think it is more of a non-windows/video driver issue of some type than something MAME can control.
No.20096 sairuk Tester Apr 27, 2022, 10:46 edited on: Apr 27, 2022, 11:32	Augusto, I understand you mentioned opengl/vulkan are similar. Please confirm your GPU operation, see my notes below. Run mame with -bgfx_debug and confirm your running mode and device in the top left of the screen Please make sure when using Vulkan, MAME is running with GPU Vulkan drivers and not the MESA software implementation, I found Ubuntu 22.04 was selecting MESA lavapipe in for Vulkan on my system instead of the GPU icd file, lavapipe is MESA's software vulkan implementation I worked around this (i expect its a distro issue) issue here by forcing the Vulkan icd file at launch for my AMD card with (yours will be different): VK_ICD_FILENAMES=/usr/share/vulkan/icd.d/radeon_icd.x86_64.json ./mame ... --- kept for reference --- This seems to be happening for me, If rendering the gameslist only, $ mame -video bgfx -bgfx_backend vulkan Fullscreen: approx 30% usage all cores Windowed: approx 20% usage all cores $ mame -video bgfx -bgfx_backend opengl No impact, core usage remained pretty close to normal for system Running Virtua Racing $ mame vr Average speed: 100.00% (29 seconds) negligable change in core usage $ mame vr -video bgfx -bgfx_backend opengl Average speed: 100.00% (32 seconds) negligable change in core usage $ mame vr -video bgfx -bgfx_backend vulkan Average speed: 92.75% (28 seconds) approx 40-50% all cores $ mame -version 0.242 (mame0242) Distro: Ubuntu 22.04 LTS Kernel: 5.15.0-25-generic CPU: AMD Ryzen 7 3700X 8-Core Processor RAM: 32GiB GPU: Device: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] (rev e7) Driver: 4.6 (Core Profile) Mesa 22.0.1 Info: AMD Radeon RX 580 Series (polaris10, LLVM 13.0.1, DRM 3.42, 5.15.0-25-generic)
No.20168 ozfalcon Tester May 7, 2022, 03:40 edited on: May 7, 2022, 03:45	Running Debian 11 (Bullseye) using nVidia GT1030 (Budget Card) with nvidia-kernel-460.91.03. Vulkan ./sdlmamearcade64.V0242.Mainline vr -video bgfx -bgfx_backend vulkan -window ./sdlmamearcade64.V0242.Mainline vr -video bgfx -bgfx_backend vulkan -nowindow Both appear to use around 23-24% CPU OpenGL ./sdlmamearcade64.V0242.Mainline vr -video bgfx -bgfx_backend opengl -nowindow Uses around 23-24% CPU ./sdlmamearcade64.V0242.Mainline vr -video bgfx -bgfx_backend opengl -window Used around 26-27% CPU Debug The UI is flipped for Vulkan (See attached images)
No.20176 Augusto Tester May 11, 2022, 05:29	Thanks for all replies. I had used BGFX Auto, OpenGL and Vulkan. I need more tests before post an reply about an solution fixed it.
No.20179 Augusto Tester May 13, 2022, 10:57	Here MAME was the only program using all cpu cores even thus having slow performance, but only if enabling BGFX. Using OpenGL had correct performance. Thus I had posted here sharing that problem. The problem was in OS using Mesa when selecting BGFX. Reinstalling Nvidia driver had fixed it. Possibly had restored default configuration files. Thus is how the correct install order : sudo apt-get update sudo apt-get upgrade sudo apt-get install pkg-config sudo apt-get install build-essential sudo apt-get install libglvnd-dev sudo apt-get install libglvnd-dev:i386 sudo apt-get install dkms sudo apt-get install libc6 sudo apt-get install mesa and last step installing Nvidia Driver Nvidia Forums has many topics about that same problem. Mesa files not having any file named Nvidia. Is how if Nvidia not allow Mesa accessing Geforce video cards resulting in problems. Have softwares need Mesa installed even if Mesa not will be used for video API. Thus is better install before Nvidia driver install. Now the topic is for reference if others users have the same problem. Have an nice day.
No.20189 Tafoid Administrator May 16, 2022, 23:20	So, the OP's issues are resolved as a system configuration issue? Closing.