Bug 97741 - PerformanceTests/CSS/StyleSheetInsert.html has a time-dependent non-Gaussian distribution
Summary: PerformanceTests/CSS/StyleSheetInsert.html has a time-dependent non-Gaussian ...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Tools / Tests (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Ryosuke Niwa
URL:
Keywords:
Depends on:
Blocks: 77037 97743
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Reported: 2012-09-26 16:48 PDT by Ryosuke Niwa
Modified: 2012-09-27 16:38 PDT (History)
4 users (show)

See Also:

Attachments
Results page illustrating the problem (20.60 KB, text/html)
2012-09-26 16:49 PDT, Ryosuke Niwa 		no flags Details
Fixes the bug (2.41 KB, patch)
2012-09-26 16:53 PDT, Ryosuke Niwa 		no flags Details | Formatted Diff | Diff
View All Add an attachment (proposed patch, testcase, etc.)

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Description Ryosuke Niwa 2012-09-26 16:48:41 PDT 
http://trac.webkit.org/browser/trunk/PerformanceTests/CSS/StyleSheetInsert.html's run function adds new nodes in each run but doesn't remove them. As a result, run gets slower on each call, resulting in values like:
22.0, 26.0, 27.0, 31.0, 33.0, 35.0, 37.0, 43.0, 44.0, 45.0

We need to remove the nodes added in each run so that values follow a normal distribution.
Comment 1 Ryosuke Niwa 2012-09-26 16:49:29 PDT 
Created attachment 165897 [details]
Results page illustrating the problem
Comment 2 Ryosuke Niwa 2012-09-26 16:53:01 PDT 
Created attachment 165898 [details]
Fixes the bug
Comment 3 Ryosuke Niwa 2012-09-26 17:04:31 PDT 
Note that the results obtained after this patch is included in the first attachment. Notice the standard deviation went down from ~25% to ~8%.
Comment 4 Ryosuke Niwa 2012-09-27 15:24:04 PDT 
I'm making results page warn time-dependent distributions in https://bugs.webkit.org/show_bug.cgi?id=97818 so that we can detect these problems easily.
Comment 5 Ryosuke Niwa 2012-09-27 16:38:16 PDT 
This bug is beautifully visualized in https://bug-97818-attachments.webkit.org/attachment.cgi?id=166055.
Comment 6 Ryosuke Niwa 2012-09-27 16:38:44 PDT 
Comment on attachment 165898 [details]
Fixes the bug

Clearing flags on attachment: 165898

Committed r129817: <http://trac.webkit.org/changeset/129817>
Comment 7 Ryosuke Niwa 2012-09-27 16:38:46 PDT 
All reviewed patches have been landed.  Closing bug.