1732726 - Use PBO uploads on Windows

Status: RESOLVED WONTFIX

(Core :: Graphics: WebRender, enhancement, P3)

Comment 1

[Nicolas Silva [:nical]]

Attachment: Bug 1732726 - Use PBO uploads on Windows. r=#gfx-reviewers

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fa3496e5bb76
Use PBO uploads on Windows. r=gfx-reviewers,gw

Comment 3

[Sandor Molnar[:smolnar]]

Backed out for causing mulitple failures on win webrender

Backout link

Push with failures

Failuire log dt3

Failuire log dt2

Failuire log crashtest

Failuire log talos

Comment 4

[Nicolas Silva [:nical]]

I see two flavors of what is probably the same issue, both of which coming from gl::map_buffer_range:

• One shows up as out-of-memory errors raised by the GL implementation (gl error 0x505) (picked up by the assertion on gl errors pref).
• The other is with HRESULT 0x887A000A (DXGI_ERROR_WAS_STILL_DRAWING) leading to "Failed to transiently map PBO of size 1048576 bytes" in get_pbo. That size is the default PBO size, not surprising nor unreasonable.

The latter is a bit worrying since we use fence objects to ensure upload PBOs are not recycled while they are still in use.

I ran tsvgx locally and didn't find content in there causing us to upload an unreasonable amount of blob pixels in the same frame.

Comment 5

[Nicolas Silva [:nical]]

Attachment: Bug 1732726 - Delay PBO reuse if fences don't work. r=#gfx-reviewers

With ANGLE we can run into DXGI_ERROR_WAS_STILL_DRAWING errors when trying to map a PBO even if we are using a fence to ensure the GPU is done.