graphics: optimize getNvidiaSmi()

[jhgg]

narrows down candidate directories smarter, uses stat to check for file existence instead of listing all files in the directory and then checking inside that array, and also avoids calling stat for the same file multiple times.

[jhgg]

this may or may not be true. we may want to broaden this to just look inside all directories that start with nv (case insensitive.)

[apacheli]

Heloo jhgg,

Thanks for letting my borrow you lamborghini that one day.

[WamWooWam]

at least on my system, nvidia-smi is just sitting in C:\Windows\system32, would it be an idea to add a fastpath for that case?

[jhgg]

at least on my system, nvidia-smi is just sitting in C:\Windows\system32, would it be an idea to add a fastpath for that case?

from my understanding that's a legacy path. can you check the creation time?

[WamWooWam]

11/07/2024, last time i updated my drivers

[x3rt]

11/07/2024, last time i updated my drivers

Mine is also located in C:\Windows\System32

Created: ‎July ‎21, ‎2024
Modified: ‎July ‎11, ‎2024

So I am assuming I installed the driver on the 21st, and it was released on the 11th

[sylveon]

When a driver is installed, it gets staged into the driver store, and then most of its files get a corresponding symlink in System32 (via the CopyFiles directive in the driver's .inf). Thus, we can expect there to be a nvidia-smi.exe in System32 which matches the currently installed driver. If nvidia-smi.exe is missing, there is no Nvidia driver on the system.

PS C:\Users\Sylveon> Get-ChildItem -Path "C:\Windows\System32\nvidia-smi.exe" | ft FullName,LinkType,Target

FullName                           LinkType Target
--------                           -------- ------
C:\Windows\System32\nvidia-smi.exe HardLink {C:\Windows\System32\DriverStore\FileRepository\nvdm.inf_amd64_0d61be38b98be4ce\nvidia-smi.exe}

There is absolutely no need to scan the driver store.

[sylveon]

We can be sure nvidia-smi.exe always gets symlinked, because, when looking at a driver's INF file, we can find the following:

And every section in the driver INF has a CopyFile directive for that:

It's not legacy, as they do not implement the corresponding state for Run From Driver Store