High CPU usage from newsticker on www.jpost.com (in painting)




7 years ago
7 years ago


(Reporter: mgroeber, Unassigned)



9 Branch
Windows 7

Firefox Tracking Flags

(Not tracked)




(2 attachments)



7 years ago
User Agent: Mozilla/5.0 (Windows NT 6.1; rv:9.0.1) Gecko/20100101 Firefox/9.0.1
Build ID: 20111220165912

Steps to reproduce:

 - Open www.jpost.com in Firefox 9
 - Close layer ads, if any
 - Wait for page to finish loading

For comparison:

 - Load same page in Internet Explorer 9

Actual results:

 - Observe CPU load in Firefox: CPU goes up to 100% whenever "Breaking News" ticker is changing, and goes to 0% while ticker is static. 
 - When bringing another tab to foreground or minimizing Firefox, CPU usage also remains near 0%.

 - Observe CPU load in Internet Explorer: CPU usage remains below 10% throughout

 - I did some preliminary profiling with xperf on Firefox, and noticed the following functions being among the top CPU consumers during the "spikes":


 - Using DOM Inspector to delete the jp-hp-breakingnews <div> element also reduces CPU usage to 0%.

Expected results:

CPU usage should have remained low in Firefox even while ticker is updating.

Note: this appears to be in the same category as bug 142994, but as suggested by David Baron I am filing this separately until it has been established that the cause is the same. Unlike some of the other tickers, this one here is not scrolling, but only appends text character-by-character to a single line.


7 years ago
Summary: High CPU usage from newsticket on www.jpost.com → High CPU usage from newsticker on www.jpost.com

Comment 1

7 years ago
Hey, It seems to be working for me. Could you just try viewing the page in safe mode and then ping back here with the results.

Comment 2

7 years ago
Thanks - viewing the page in Safe Mode doesn't make a difference for me: I still see CPU activity spiking to 100% (on one CPU core) for a second or two while the Breaking News ticker is updating, and then fall back to zero until the next update.


7 years ago
Component: Untriaged → Graphics
Keywords: perf
Product: Firefox → Core
QA Contact: untriaged → thebes
Summary: High CPU usage from newsticker on www.jpost.com → High CPU usage from newsticker on www.jpost.com (in painting)
Cannot replicate on MacOS X using FF12.
Created attachment 613184 [details]
profile data for http://varium.fantasytalesonline.com/cleopatra/

FWIW, I can reproduce on a nightly using a clean profile (Mac OS 10.7, both with integrated and discrete graphics, as far as I can see). Here's a sample from the built-in profiler (from a profiling-nightly build) for use with http://varium.fantasytalesonline.com/cleopatra/
Created attachment 613185 [details]
screenshot of the profiler: 35% spent in painting

and a screenshot of the profile in cleopatra. The data was collected during the ~2 seconds while the ticker was updating, about 35% of that time is spent in painting (and 50% idle).
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