2016747 - 82.09 - 8.64% pdfpaint issue14982.pdf / pdfpaint issue16485.pdf + 1 more (Linux) regression on Thu February 12 2026

Status: RESOLVED FIXED

(Core :: Privacy: Anti-Tracking, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a talos performance regression from push 0ce65c52065cc112512124478d979e1fb52e7e91. As author of one of the patches included in that push, we need your help to address this regression.

Please acknowledge, and begin investigating this alert within 3 business days, or the patch(es) may be backed out in accordance with our regression policy.

Regression	Test	Platform	Options	Absolute values [old vs new]
82%	pdfpaint issue14982.pdf (doc)	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	760.90 ms -> 1,385.50 ms
9%	pdfpaint issue16485.pdf (doc)	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	372.73 ms -> 407.13 ms
9%	pdfpaint issue16485.pdf (doc)	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	377.60 ms -> 410.20 ms

Support & Actionable Steps

For questions, please contact [e-mail]. You can also find help on Slack (#perf-help) or Matrix (#perftest).

Action guide details:

• See the guide to handling regression bugs for investigation steps.
• Review the alert summary for affected tests, graphs, and comparisons.
• Check the PerfCompare results.
• Tests on Try: Run all tests using ./mach try perf --alert 48683 (See documentation link for details).
• Profiling jobs: Trigger jobs from Treeherder job view or request them from [e-mail].

Comment 1

[Liz Henry (:lizzard)]

Noting that we did back out the patches in bug 1990514, though we will likely try re-landing them soon.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

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

:tjr, since you are the author of the regressor, bug 1990514, 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

[BugBot [:suhaib / :marco/ :calixte]]

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

:tjr, since you are the author of the regressor, bug 1990514, 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 4

[Tom Ritter [:tjr]]

This should no longer be an issue - we backed out the bug that caused the regression; landed Bug 1918257 to exempt pdfjs so this regression would not occur, then relanded 1990514