Skiasharp: [BUG] Much higher RAM usage on x64 compared with x86

[Mikolaytis]

Description

We are putting images to GPU(texture based SKImage) to render them later with perfect performance.
On x86 build images are allocating only GPU RAM.
On x64 build images are allocating also CPU RAM.

This is a huge issue for us 👎. App is working some times slower on x64 and eating a lot more RAM, like 10 times more in some cases(200mb vs 2gb), because we store a lot images on GPU.

I've provided a repro project repo link below.

Code

using (var surf = SKSurface.Create(_grContext, false, _imageInfo, 1, GRSurfaceOrigin.TopLeft))
{
    surf.Canvas.DrawImage(_rasterImg, 0, 0);
    surf.Canvas.Flush();
    _textureImages.Add(surf.Snapshot());
}

Is there a better way to transform raster image to texture-backed image? We've tried to create textures and then push image to it - but this approach generated some artifacts on rendering.

Expected Behavior

On x86 Snapshot() SKImage is allocating only GPU memory
On x64 Snapshot() SKImage is allocating only GPU memory

Actual Behavior

On x64 Snapshot() SKImage is allocating only GPU memory
On x64 Snapshot() SKImage is allocating GPU and CPU memory

Basic Information

• Version with issue: 1.68
• IDE: Visual Studio
  
  
  
  • Windows Classic: Windows 10
  
  
• Target Devices: High-end PC

Reproduction Link

https://github.com/Mikolaytis/SkiaSharpMemoryIssue

[AndreyGrishin]

Yes, this is really a problem(

[marizombie]

+1. Our team would highly appreciate your attention to this issue.

[Donsezan]

This is a big problem! Please help!

[Mikolaytis]

New prerelease 1.68.1-pre did not fix this issue

[Mikolaytis]

Update:
Turns out there is no issue about increased memory usage on x64. It has an another behavior on x64.

On x86 test prefers to use shared GPU memory,

_(shared GPU memory was used by x86 launch and disposed after test end)_

but x64 test prefers to use just a process RAM, not shared GPU memory.

_(second test on x64 started right after first, you can see a rise on GPU memory, but nothing is going in the shared GPU memory - because somehow it started to eat regular RAM)_

It can be:

1. a driver issue
2. an OpenGL issue
3. Windows issue
4. Skia issue
5. SkiaSharp issue

Now I think that this is not an issue at all. Because it looks like it does not matter how used RAM will be named in Windows - shared GPU RAM or regular RAM, it should work almost the same as I believe. So I think I can close this issue.