Bug 79781 - Web Inspector: weird performance when inspector is open
Summary: Web Inspector: weird performance when inspector is open
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Web Inspector (Deprecated) (show other bugs)
Version: 528+ (Nightly build)
Hardware: PC Linux
: P2 Normal
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-02-28 05:17 PST by eustas.bug
Modified: 2012-10-22 05:48 PDT (History)
4 users (show)

See Also:

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description eustas.bug 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.
Comment 1 Vivek Galatage 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.
Comment 2 Yury Semikhatsky 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.