Bug 155809 - Web Inspector: Ensure maximum accuracy while profiling
Summary: Web Inspector: Ensure maximum accuracy while profiling
Alias: None
Product: WebKit
Classification: Unclassified
Component: Web Inspector (show other bugs)
Version: WebKit Nightly Build
Hardware: All All
: P2 Normal
Assignee: Joseph Pecoraro
Keywords: InRadar
Depends on: 152193
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Reported: 2016-03-23 15:06 PDT by Joseph Pecoraro
Modified: 2016-03-28 20:28 PDT (History)
10 users (show)

See Also:

patch (8.82 KB, patch)
2016-03-23 17:59 PDT, Saam Barati
no flags Details | Formatted Diff | Diff
[PATCH] Proposed Fix (12.79 KB, patch)
2016-03-28 19:11 PDT, Joseph Pecoraro
no flags Details | Formatted Diff | Diff
[IMAGE] Debugger Sidebar during recording (253.86 KB, image/png)
2016-03-28 19:21 PDT, Joseph Pecoraro
no flags Details

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Description Joseph Pecoraro 2016-03-23 15:06:12 PDT
Script & Events should have a High Fidelity Profiling mode.

In this mode we would disable things that can affect performance while the inspector is open, allowing developers to profile the absolute maximum performance JavaScript while the Inspector is open.

  - disable breakpoints (see bug 152193) to disable debugger deoptimizations
  - disallow or warn if used with other expensive timelines (Heap Allocations)
  - maybe disable some domains (CSS / DOM) to avoid updates during recording?
  - maybe reduce the sample interval to get more samples?

- When starting / stopping recording, save & disable breakpoints then restore breakpoints setting to whatever it was
- While recording, prevent the inspector from enabling breakpoints
Comment 1 Radar WebKit Bug Importer 2016-03-23 15:06:59 PDT
Comment 2 Saam Barati 2016-03-23 17:59:22 PDT
Created attachment 274803 [details]
Comment 3 Saam Barati 2016-03-23 17:59:51 PDT
Comment on attachment 274803 [details]

oops wrong bug
Comment 4 Joseph Pecoraro 2016-03-28 18:59:30 PDT
Retitling. Instead of having an opt-in high fidelity profiling mode we should just always do the best we can when timeline recording. That means automatically disabling breakpoints and re-enabling them (if needed) when doing a timeline recording.
Comment 5 Joseph Pecoraro 2016-03-28 19:11:52 PDT
Created attachment 275075 [details]
[PATCH] Proposed Fix
Comment 6 Joseph Pecoraro 2016-03-28 19:21:19 PDT
Created attachment 275076 [details]
[IMAGE] Debugger Sidebar during recording
Comment 7 WebKit Commit Bot 2016-03-28 20:28:10 PDT
Comment on attachment 275075 [details]
[PATCH] Proposed Fix

Clearing flags on attachment: 275075

Committed r198774: <http://trac.webkit.org/changeset/198774>
Comment 8 WebKit Commit Bot 2016-03-28 20:28:14 PDT
All reviewed patches have been landed.  Closing bug.