RESOLVED FIXED 79781
Web Inspector: weird performance when inspector is open 
https://bugs.webkit.org/show_bug.cgi?id=79781
Summary Web Inspector: weird performance when inspector is open
eustas.bug
Reported 2012-02-28 05:17:28 PST
When I open Inspector, performance goes down more than 10x. But when I start JavaScript CPU profiling, performance goes back to almost normal.
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Vivek Galatage
Comment 1 2012-03-02 07:38:58 PST
Which port are we experiencing this performance issue? Gtk/Qt? I tried this with QtTestBrowser built using the build-webkit for Qt port under ubuntu 11.10 and couln't see much difference in performance. Only a slight spike was observed in the system monitor for CPU during the inspector load and then eventually it came down to normal. Same was observed while starting the Javascript CPU profiling.
Yury Semikhatsky
Comment 2 2012-03-02 08:20:49 PST
There was a problem in how V8 calculates //@ sourceUrl for large scripts(several megabytes). When capturing callstack e.g. for console messages we repeat this operation for each callframe which may be noticeably slow. We fixed that in V8 by caching search result: https://code.google.com/p/v8/source/detail?r=10902 this may need to be done for JSC as well.
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