129165 - High CPU usage while Mozilla is not being used actively

Status: RESOLVED DUPLICATE of bug 120154

(SeaMonkey :: General, defect)

Description

[Matt Lee]

Mac OS X 10.1.3 (build 5Q45) and Mozilla Build ID: 2002030508. This is a nightly
build downloaded from the direct links in the lower right of mozilla.org.

Using top, I have noticed a trend for Mozilla to use inordinate amounts of CPU
time while it is not doing anything. For example, I can open a Mozilla window,
load a page, and then minimize it (to the Dock). Mozilla then fluctuates in CPU
usage, from a low of about 7-10%, to an average at about 30-45%, and maxing out
around 62%.

This is just using normal Web pages and not meta refresh type pages or anything
like that. This should not happen; Mozilla should use zero CPU time when I am
not using it (assuming it's not reloading a page or something in the background).

Comment 1

[Matt Lee]

(added perf keyword)

Sorry, I forgot to mention this is on a 400 MHz Power Mac G4. (relevant to CPU
load percentages)

Comment 2

[Boris Zbarsky [:bzbarsky]]

Does the page have animated gifs?  Flash?  Java applets?

Comment 3

[Matt Lee]

Sigh...so obvious and I didn't think of it because they were in a tab. Yes, the
page has a few animated gifs. No Flash/Java though. Perhaps the animations
should be paused if they are not in the foreground tab, or if the window is
minimized?

Also, with just this bugzilla window open, Mozilla still hovers around 3-4% of
my CPU. Way better than the 60% I was seeing with the animations, but still
nonzero. What could it be doing?

Comment 4

[Boris Zbarsky [:bzbarsky]]

Duplicate of "animated GIF eating cpu when mozilla in another tab or minimized"

*** This bug has been marked as a duplicate of 120154 ***