645761 - [Mac] High CPU usage when viewing animated GIFs

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[d.a.]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.2a1pre) Gecko/20110328 Firefox/4.2a1pre
Build Identifier: 

When viewing pages with lots of animated GIFs the CPU usage goes up considerably. 

Visiting the link above I get a CPU usage for the Firefox process of around 40%, with window_server getting 25-30%, no difference between running Firefox in 32 or 64-bit mode. Disabling hardware acceleration drops window_server to about 5-10%.

Visiting the same page in Safari gives a CPU usage of about 10% and window_server of 5-10%.

I'm attaching a 5 sec sample of the Firefox process.

Reproducible: Always

Comment 1

[d.a.]

Attachment: The Firefox Sample

Comment 3

[Boris Zbarsky [:bzbarsky]]

This is likely a different bug, especially if a bunch of the time is spent in GL compositing (see windowserver), since I can tell you for a fact that's not happening on XP.  ;)

Comment 4

[Joe Drew (not getting mail)]

Lots of animated gifs no longer paint too much, so this should be significantly better now.