1679863 - HTMLCanvasElement.getContext is slow

Status: NEW

(Core :: Security: Process Sandboxing, task, P5)

Description

[Olli Pettay [:smaug][[e-mail]]]

The profile seems to hint that sandboxing is adding non-trivial overhead
https://share.firefox.dev/3ljFFmR

The profile was created by loading youtube.com and then clicking one of the suggested videos. The profile is from 64 bit linux, the results might be quite different on other platforms.

Comment 1

[Gian-Carlo Pascutto [:gcp]]

It's invoking the OpenGL drivers, which seem to be opening a lot of files (a lot of time spent in "open" calls). That indeed has to be intercepted by the sandbox, forwarded to the parent, checked against a whitelist, and the result sent back.

We are remoting all WebGL operations to get rid of this kind of thing (drivers messing around on the filesystem), so this will be fixed by bug 1638466.

Comment 2

[Gian-Carlo Pascutto [:gcp]]

Jeff Gilbert noted that this could be an issue again if we decide to sandbox the GPU process with filesystem access restrictions.

Comment 3

[Alex Thayer [:alexical] (she/her)]

Giving this qf:p5 - should reevaluate after 1638466 or if anything changes WRT sandboxing the GPU process per comment 2.