972392 - Canvas 2D has high power consumption on Linux

Status: NEW

(Core :: Graphics: Canvas2D, defect)

Description

[Roberto Agostino Vitillo (:rvitillo)]

Attachment: Power consumption on Linux

When running the test case with FF, the X server process is constantly around 70% in top while with chrome it never goes above 5%.

Also note that on OSX the power consumption of Chrome is much higher but while on Chrome the animation is smooth the same cannot be said for FF, at least not on my machine.

Comment 1

[Benoit Girard (:BenWa)]

bjacob, what prefs should we re-run this test with?

Comment 2

[Benoit Jacob [:bjacob] (mostly away)]

Very interesting work, I would suggest that you check if setting these preferences makes a difference:

layers.acceleration.force-enabled = true  (boolean)
gfx.canvas.azure.backends = skia          (string)
gfx.canvas.azure.accelerated = true       (boolean, you might have to create it)

Comment 3

[Benoit Girard (:BenWa)]

If it's easy to run the test I'd suggest running:
(1), (2), (1+2), (1+2+3)

where:

(1) layers.acceleration.force-enabled = true  (boolean)
(2) gfx.canvas.azure.backends = skia          (string)
(3) gfx.canvas.azure.accelerated = true       (boolean, you might have to create it)

You should double check in about:support under Graphics to make sure the preferences were not ignored.

Comment 4

[Roberto Agostino Vitillo (:rvitillo)]

cairo backend - 125J
1) - 127J
2) - 110J
1+2) - 113J
1+2+3) - 120J

It looks like the X server process behaves normally when switching to the skia backend.

Comment 5

[Benoit Girard (:BenWa)]

Ok this isn't very useful. There's too much happening here so we're going to have to break this down. Right now we have (1) Some heavy Js happening, (2) A lot of canvas painting, (3) A fix overhead for compositing a changed canvas frame.

Here's two test cases to check if the problem lies in (3):
http://people.mozilla.org/~bgirard/Invalidation/canvas/

Comment 6

[Roberto Agostino Vitillo (:rvitillo)]

"canvas-overhead" drives the X sever up to about 15% while with "canvas-overhead-hidden" X never goes over 3%.