1797887 - Shader disk cache is not supported with nightly on Windows

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P1)

Description

[Sotaro Ikeda [:sotaro]]

It seems like a regression from bug 1347710 Comment 78.

I saw the following error log in about:support with latest nightly on Windows.

GP+[GFX1-]: shader-cache: Shader disk cache is not supported

The problem did not happen with pref security.sandbox.gpu.level=0.

Comment 1

[Sotaro Ikeda [:sotaro]]

Old diagram of Shader disk cache implementation.

https://github.com/sotaroikeda/firefox-diagrams/blob/master/gfx/gecko_gfx_webrender_bindings_WrProgramCache_68.pdf

Comment 2

[Jeff Muizelaar [:jrmuizel]]

Chris, the shader cache is stored at [profile-path]/shader-cache. Can we allow the gpu process access to that path?

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Hmm.. seems like this should already be allowed:
https://searchfox.org/mozilla-central/rev/85cbcecd24554c1fa88360412452ad0f7ed48630/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp#990

Comment 4

[Sotaro Ikeda [:sotaro]]

use_disk_cache in WrProgramCache::new() was false

• https://searchfox.org/mozilla-central/rev/85cbcecd24554c1fa88360412452ad0f7ed48630/gfx/webrender_bindings/src/program_cache.rs#310

Once Firefox run with pref security.sandbox.gpu.level=0, the use_disk_cache became true even with pref security.sandbox.gpu.level=1.

But the following new error message exists.

GP+[GFX1-]: shader-cache: Failed to write startup whitelist

Comment 5

[Sotaro Ikeda [:sotaro]]

gfxUtils::RemoveShaderCacheFromDiskIfNecessary() removes shader disk cache from parent process if Firefox build version or gfx driver is updated. It might be related to the following error.

GP+[GFX1-]: shader-cache: Shader disk cache is not supported

Comment 6

[Chris Martin [:cmartin]]

Attachment: Bug 1797887 - Workaround: allow access to entire filesystem from GPU sandbox r=handyman,jrmuizel

Comment 7

[Chris Martin [:cmartin]]

FWIW on my machine, the code Jeff shared in Comment 3 still works and allows access to the shader cache... So there must be some difference between machines here.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1fa40d8e9320
Workaround: allow access to entire filesystem from GPU sandbox r=handyman,jrmuizel

Comment 9

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/1fa40d8e9320

Comment 10

[Gian-Carlo Pascutto [:gcp]]

This TEMPORARY WORKAROUND should have at the very least a follow-up bug to fix the hack it introduces.

Comment 11

[Chris Martin [:cmartin]]

Whoops -- Meant to do this before I left for PTO. FWIW I did have it at the top of my notes to file a follow-up bug :)