1952527 - 1.91% damp custom.jsdebugger.open-large-minified-file.DAMP (Windows) regression on Thu February 27 2025

Status: RESOLVED WONTFIX

(DevTools :: Debugger, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a devtools performance regression from push cb56e068ecea83724815f25fc65bdc652c412d42. As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

Ratio	Test	Platform	Options	Absolute values (old vs new)
4%	damp simple.jsdebugger.open.DAMP	windows11-64-shippable-qr	e10s fission stylo webrender	231.96 -> 240.51
3%	damp simple.jsdebugger.open.DAMP	macosx1470-64-shippable	e10s fission stylo webrender	346.06 -> 356.22
3%	damp custom.jsdebugger.open-large-minified-file.DAMP	windows11-64-shippable-qr	e10s fission stylo webrender	46.96 -> 48.28
2%	damp custom.jsdebugger.open-large-minified-file.DAMP	windows11-64-shippable-qr	e10s fission stylo webrender	46.98 -> 47.88

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
8%	damp complicated.jsdebugger.close.DAMP	windows11-64-shippable-qr	e10s fission stylo webrender	11.54 -> 10.61
7%	damp complicated.jsdebugger.close.DAMP	windows11-64-shippable-qr	e10s fission stylo webrender	11.49 -> 10.64

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests. Please follow our guide to handling regression bugs and let us know your plans within 3 business days, or the patch(es) may be backed out in accordance with our regression policy.

If you need the profiling jobs you can trigger them yourself from treeherder job view or ask a sheriff to do that for you.

You can run all of these tests on try with ./mach try perf --alert 44220

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Comment 1

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 1943130

Comment 2

[BugBot [:suhaib / :marco]]

It has been over 7 days with no activity on this performance regression.

:ochameau, since you are the author of the regressor, bug 1943130, which triggered this performance alert, could you please provide a progress update?

If this regression is something that fixes a bug, changes the baseline of the regression metrics, or otherwise will not be fixed, please consider closing it as WONTFIX. See this documentation for more information on how to handle regressions.

For additional information/help, please needinfo the performance sheriff who filed this alert (they can be found in comment #0), or reach out in #perftest, or #perfsheriffs on Element.

For more information, please visit BugBot documentation.

Comment 3

[Alexandre Poirot [:ochameau]]

I've pushed to try again to confirm the regression from bug 1943130.
https://perf.compare/subtests-compare-results?baseRev=f0280751cc24533d60d8a0d6a32f24a7b0b09bc5&baseRepo=try&newRev=1afddac39dd961341ab8354720c66b1984f84e34&newRepo=try&framework=12&baseParentSignature=4763542&newParentSignature=4763542&filter_confidence=medium%2Chigh

There is only a 3.4% regression, with medium confidence, for cold.jsdebugger.open.DAMP.
But there is nothing in this patch to explain an impact on the cold test.
The cold test would highlight regression made to the very first opening of DevTools, which is most cases relates to module loading.
Here there is no change made to module loading, nor anything involved during debugger opening.

I'll assume this is some noise between tests.