Bug 11216

Summary: REGRESSION: Twice the cpu usage on idle
Product: WebKit Reporter: Kevin M. Dean <kevin>
Component: Plug-insAssignee: Nobody <webkit-unassigned>
Status: RESOLVED INVALID    
Severity: Normal CC: ap, hyatt
Priority: P2 Keywords: Regression
Version: 420+   
Hardware: Mac (PowerPC)   
OS: OS X 10.4   
URL: http://www.adobe.com/shockwave/welcome/
Attachments:
Description Flags
Webkit and Safari cpu usages
none
Reduced code none

Kevin M. Dean
Reported 2006-10-08 06:35:15 PDT
When viewing macnn.com, after the page is loaded and I'm doing nothing else, the cpu usage for webkit varies between 80-90%. Safari idles on the same page at 40-50%. Dual 2.7GHz G5 I'd guess that it's the flash-based Crucial RAM ad on the right side of the page. The cpu usage seems high even under Safari, but it doesn't make sense that it just about doubles under webkit.
Attachments
Webkit and Safari cpu usages (26.82 KB, image/png)
2006-10-15 06:01 PDT, Kevin M. Dean 		no flags
Details
Reduced code (1012 bytes, text/html)
2006-10-15 07:35 PDT, Kevin M. Dean 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Alexey Proskuryakov
Comment 1 2006-10-15 04:15:33 PDT
I'm seeing zero CPU usage on this site... Maybe because the Flash ad is gone. I guess we'll need another example to work with.
Kevin M. Dean
Comment 2 2006-10-15 05:59:13 PDT
I just had the crucial ad again with high cpu usage. The ad comes and goes I guess.
Kevin M. Dean
Comment 3 2006-10-15 06:01:24 PDT
Created attachment 11095 [details] Webkit and Safari cpu usages Not that helps at all. I've attached a screenshot of the 2 cpu usages that I just had on the page with Webkit and Safari.
Kevin M. Dean
Comment 4 2006-10-15 07:35:02 PDT
Created attachment 11096 [details] Reduced code Reduced the code to the javascript that pulls in the crucial ad. If it doesn't appear, try reloading the page until the ad changes. Although now the cpu usage is a lot less, probably due to all the other page elements missing, I'm still noticing higher usage on Webkit (10-15%) than Safari (5-10%). It seems that the flash plugin is using more cpu under Webkit than the same plugin under Safari.
Kevin M. Dean
Comment 5 2006-10-15 07:40:53 PDT
Here's a better page to test with. http://www.adobe.com/shockwave/welcome/ It's the adobe test page for the flash and shockwave plugins. I'm seeing the same increased cpu usage here as I did on the macnn.com page.
Alexey Proskuryakov
Comment 6 2006-10-15 09:48:05 PDT
With Safari in the foreground, I'm not seeing any change in CPU usage. Current versions do take more CPU in background, but I think that this change was intentional: 2006-08-14 David Hyatt <hyatt@apple.com> Fix for Radar bug 4478840, Safari should not reduce null events sent to plug-ins in windows that are inactive but visible. With this fix you can view videos in visible background windows on YouTube (for example) and not see any drop in frame rate.
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