1502740 - Enable Vulkan backend for Skia

Status: UNCONFIRMED

(Core :: Graphics, enhancement, P5)

Description

[Shmerl]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0




Expected results:

Skia now has full featured Vulkan backend available which can be chosen at runtime: https://skia.org/user/special/vulkan

Given that OpenGL backend for Skia is problematic (see bug 1468801), using Vulkan can be an advantage to enable GPU acceleration, because fixing bugs in Vulkan drivers is easier in general (they are leaner and faster to fix).

Comment 1

[Kelsey Gilbert [:jgilbert]]

I suspect it will still not be compelling vs software skia, except in some benchmarks.

Comment 2

[Shmerl]

(In reply to Jeff Gilbert [:jgilbert] from comment #1)
> I suspect it will still not be compelling vs software skia, except in some
> benchmarks.

Well, Vulkan allows reducing CPU overhead in comparison with OpenGL, so if Skia is using it properly, it's possible for it to perform better, especially with better GPU. Such option doesn't need to be a default, but it shouldn't hurt having it?

Also, may be with move to WebRender this might become unimportant in the future, but Skia is used even with WebRender currently if I'm not mistaken?

Comment 3

[Kelsey Gilbert [:jgilbert]]

Integration isn't free. It's expensive engineering-wise to maintain multiple backends, and in particular ensuring that multiple combinations of backends for different modules play nice with eachother. Having only software Skia provides engineering value, which lets us move faster at developing improvements in other areas.

It's very cool, but if the performance is not a compelling improvement, the engineering drag this would exert would point to us sticking with software Skia. Generally speaking, Skia is not a major slow-path, but maintaining SkiaGL definitely took away engineering effort from other tasks.

Comment 4

[Lee Salzman [:lsalzman]]

Agree with Jeff's assessment in comment 3. Further, to validate Vulkan drivers and their relative stability and performance, update blocklists, etc. would be too much of a headache when we're not even sure Skia's OpenGL backend is a net benefit anymore. There are many cases where the software Skia performs better for us due to a heavy reliance on paths, text, and filters.

With WebRender, we do not use or rely upon Skia acceleration, only software Skia.

Comment 5

[Shmerl]

Will for example Vulkan based WebRender benefit from Vulkan Skia backend (mixing the two like Vulkan backend for WebRender and OpenGL one for Skia would be weird).

Comment 6

[Lee Salzman [:lsalzman]]

(In reply to Shmerl from comment #5)
> Will for example Vulkan based WebRender benefit from Vulkan Skia backend
> (mixing the two like Vulkan backend for WebRender and OpenGL one for Skia
> would be weird).

We don't use Skia acceleration with WebRender and have no plans to, so no, basically.