1231396 - Add a painted pixels per second counter

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect)

Description

[Jeff Muizelaar [:jrmuizel]]

This would be very helpful to get a feel for how much painting we're doing when using APZ

Comment 1

[Kartikaya Gupta (email:[e-mail])]

What's a good place to record this? Somewhere in Moz2D I would imagine. Although... that might pick up other things like thumbnailing which we might not want, so we might need something to enable/disable the counting.

Comment 2

[Jeff Muizelaar [:jrmuizel]]

I expect the best place is probably somewhere at the end of layout. i.e. We want to sum the invalidated area each time we paint and send that to the compositor so that it can compute the necessary statistics.

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Layout should also probably timestamp the beginning and end of painting so that we have an accurate picture of our painting rate.

Comment 4

[Kartikaya Gupta (email:[e-mail])]

I think we already tell the profiler whenever a paint happens, maybe we can also tell it how many pixels were painted for that paint. It already knows how long it took.

Comment 5

[Kartikaya Gupta (email:[e-mail])]

Attachment: WIP

Not sure if this quite correct but it's a start.

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Attachment: Patch

Here's a beefed-up version. I used the gfx.logging namespace because setting any pref that starts with "layers.dump" will turn on layers dumping.

Comment 7

[Markus Stange [:mstange]]

Comment on attachment 8742951 [details] [diff] [review]
Patch

Review of attachment 8742951 [details] [diff] [review]:
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Looks good. Have you considered adding this to the FPS counter?

Comment 8

[Kartikaya Gupta (email:[e-mail])]

I find the numbers (for the pixels in the last second) vary a lot in practice, from ~0 to upwards of 3 million, on my laptop so I'm not sure how valuable it would be in a transient display like the FPS counter. I did find it useful as output that I could collect and run stats on though.

Comment 9

[Kartikaya Gupta (email:[e-mail])]

Landing for now, if there's a strong desire to see this in the FPS counter I can do so in another bug.

Comment 10

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/dc6cc76f3c7e

Comment 11

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/dc6cc76f3c7e