Bug: 103.15 - 19.13% tp5o responsiveness / tp5o_webext responsiveness + 9 more (Linux, Windows) regression on Tue November 23 2021
Status: RESOLVED
Priority: P1
Resolution: FIXED
Created: 2021-11-25 16:41:00+00:00
Resolved: 2021-12-07 22:03:45+00:00

Perfherder has detected a talos performance regression from push [1d2d2a48cec9606a22bc5589c932baf6672d6de4](https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=1d2d2a48cec9606a22bc5589c932baf6672d6de4). 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)**| 
|--|--|--|--|--| 
| 103% | [tp5o](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o) responsiveness | windows10-64-shippable-qr | e10s stylo webrender-sw | 0.44 -> 0.90 |
| 87% | [tp5o](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o) responsiveness | windows10-64-shippable-qr | e10s stylo webrender | 0.46 -> 0.85 |
| 68% | [tp5o](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o) responsiveness | windows10-64-shippable-qr | e10s stylo webrender | 0.56 -> 0.93 |
| 64% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | windows10-64-shippable-qr | e10s stylo webrender | 1.05 -> 1.71 |
| 61% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | windows10-64-shippable-qr | e10s stylo webrender-sw | 1.04 -> 1.67 |
| 37% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | windows10-64-shippable-qr | e10s fission stylo webrender | 1.97 -> 2.71 |
| 29% | [tp5o](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o) responsiveness | linux1804-64-shippable-qr | e10s stylo webrender | 2.15 -> 2.78 |
| 28% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | linux1804-64-shippable-qr | e10s stylo webrender-sw | 4.14 -> 5.32 |
| 27% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | linux1804-64-shippable-qr | e10s stylo webrender | 3.93 -> 5.01 |
| 26% | [tp5o](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o) responsiveness | linux1804-64-shippable-qr | e10s stylo webrender-sw | 2.32 -> 2.93 |
| 19% | [tp5o_webext](https://firefox-source-docs.mozilla.org/testing/perfdocs/talos.html#tp5o-webext) responsiveness | linux1804-64-shippable-qr | e10s fission stylo webrender | 6.53 -> 7.78 |


Details of the alert can be found in the [alert summary](https://treeherder.mozilla.org/perfherder/alerts?id=32486), including links to graphs and comparisons for each of the affected tests. Please follow our [guide to handling regression bugs](https://wiki.mozilla.org/TestEngineering/Performance/Handling_regression_bugs) and **let us know your plans within 3 business days, or the offending patch(es) will be backed out** in accordance with our [regression policy](https://www.mozilla.org/en-US/about/governance/policies/regressions/).

For more information on performance sheriffing please see our [FAQ](https://wiki.mozilla.org/TestEngineering/Performance/FAQ).