925413 - Find out why drawing the nav-bar background is 10x more expensive on the UX branch

Status: RESOLVED FIXED

(Firefox :: Theme, defect)

Description

[Mike Conley (:mconley) (:⚙️)]

According to the more recent reflow profiles for Snow Leopard posted in bug 902024, drawing the background of the nav-bar got 10x more expensive. What used to cost about 4ms across the entire TART suite costs something like ~40ms now.

Removing all backgrounds on the nav-bar showed a performance win on Snow Leopard:

http://compare-talos.mattn.ca/?oldRevs=363f0ff307d5&newRev=02e3681bb65c&server=graphs.mozilla.org&submit=true

So why? What got so expensive?

MattN was looking at this.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

I'm curious to know whether bug 925514 has fixed this. I'll get some up-to-date reflow profiles and see what they say.

Comment 2

[Mike Conley (:mconley) (:⚙️)]

Here's an up-to-date comparison profile:

http://tests.themasta.com/cleopatra/?report=b004c6cbb2d0649bcacd3e124a884bba38acadc9

Now looking at the nav-bar background image measurement, we spend almost an equal amount of time drawing it as we do on m-c. \o/

So I think it's safe to say that bug 925514 took care of this. Closing this bug.