1913969 - 0.01% Base Content JS (Linux) regression on Fri August 9 2024

Status: RESOLVED INVALID

(WebExtensions :: General, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a awsy performance regression from push 8b56107c9c8f115b5f08b4edf635a9b56932c200. As author of one of the patches included in that push, we need your help to address this regression.

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
0.01%	Base Content JS	linux1804-64-shippable-qr	fission	1,508,780.00 -> 1,508,579.33

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 these tests on try with ./mach try perf --alert 1731

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Comment 1

[Dianna Smith [:diannaS]]

i think this was fixed by backout.
:robw can you confirm? it is hard to tell because it is so minor.

Comment 2

[Rob Wu [:robwu]]

It is unlikely for the patch in bug 1634240 to have affected the Base Content JS test.

The patch only modifies the implementation of the windows.onFocusChanged extension API event, which is not active when there are no extensions. I don't see any uses of this event outside of extension unit tests in the tree.

Moreover, the alleged performance regression is in measured memory usage in the content process. The report shows that the numbers went down, which would actually be an improvement rather than a regression.