Bug: 32.47 - 8.33% twitch SpeedIndex / reddit ContentfulSpeedIndex + 5 more (Linux, OSX, Windows) regression on Thu August 3 2023
Status: NEW
Priority: --
Created: 2023-08-11 08:18:12+00:00
Resolved: 2025-02-10 21:34:10+00:00

Perfherder has detected a browsertime performance regression from push [58d067f89f59472dc1a89d573ccebb4850863efa](https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=58d067f89f59472dc1a89d573ccebb4850863efa). 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)** |  **Performance Profiles** | 
|--|--|--|--|--|--| 
| [32%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779716,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) SpeedIndex | macosx1015-64-shippable-qr | cold fission webrender | 884.30 -> 1,171.43 |  |
| [31%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779721,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) PerceptualSpeedIndex | macosx1015-64-shippable-qr | cold fission webrender | 600.98 -> 785.25 |  |
| [31%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777140,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) SpeedIndex | linux1804-64-shippable-qr | cold fission webrender | [1,056.06](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/WUIASx9HTBe7EbWx4GjY6Q/runs/0/artifacts/public/test_info/browsertime-results.tgz) -> [1,378.43](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/chn8Mq1sSqCgUfkdbUvSiA/runs/0/artifacts/public/test_info/browsertime-results.tgz) |  |
| [20%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777145,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) PerceptualSpeedIndex | linux1804-64-shippable-qr | cold fission webrender | [765.02](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/WUIASx9HTBe7EbWx4GjY6Q/runs/0/artifacts/public/test_info/browsertime-results.tgz) -> [916.12](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/chn8Mq1sSqCgUfkdbUvSiA/runs/0/artifacts/public/test_info/browsertime-results.tgz) |  |
| [17%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779719,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) ContentfulSpeedIndex | macosx1015-64-shippable-qr | cold fission webrender | 1,116.32 -> 1,311.55 |  |
| [11%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777805,1,13)  | [tumblr](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#tumblr-d) fcp | windows10-64-shippable-qr | cold fission webrender | [296.04](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/TkIX3QmrQYKyWShgsO5x7Q/runs/0/artifacts/public/test_info/browsertime-results.tgz) -> [327.50](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/bF14bUFiS1WYIUzOwnbMAg/runs/0/artifacts/public/test_info/browsertime-results.tgz) | [Before](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FTkIX3QmrQYKyWShgsO5x7Q%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_tumblr.zip)/[After](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FbF14bUFiS1WYIUzOwnbMAg%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_tumblr.zip) |
| [8%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779995,1,13)  | [reddit](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#reddit-d) ContentfulSpeedIndex | macosx1015-64-shippable-qr | cold fission webrender | [447.53](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/bzot0w29Tx2sFRstFJz7jQ/runs/0/artifacts/public/test_info/browsertime-results.tgz) -> [484.81](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/emVzs37nS0KOgjwXTEDsxw/runs/0/artifacts/public/test_info/browsertime-results.tgz) |  |
### Improvements:

| **Ratio** | **Test** | **Platform** | **Options** | **Absolute values (old vs new)** |  **Performance Profiles** | 
|--|--|--|--|--|--| 
| [29%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779718,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) LastVisualChange | macosx1015-64-shippable-qr | cold fission webrender | 5,559.65 -> 3,971.50 |  |
| [26%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777142,1,13)  | [twitch](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#twitch-d) LastVisualChange | linux1804-64-shippable-qr | cold fission webrender | 7,572.18 -> 5,610.28 |  |
| [11%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777886,1,13)  | [microsoft](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#microsoft-d) LastVisualChange | windows10-64-shippable-qr | cold fission webrender | 571.99 -> 510.22 |  |
| [9%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777887,1,13)  | [microsoft](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#microsoft-d) ContentfulSpeedIndex | windows10-64-shippable-qr | cold fission webrender | 342.00 -> 309.57 |  |
| [8%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3870117,1,13)  | [bing-search](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#bing-search-d) LastVisualChange | windows10-64-shippable-qr | cold fission webrender | 810.69 -> 748.91 | [Before](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FPhlWlnS1QhO2SoCtBwmGcA%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_bing-search.zip)/[After](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FC3WQJoDBQPyzg6KC-1_wFA%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_bing-search.zip) |
|...|...|...|...|...|...|
| [2%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3777082,1,13)  | [youtube](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#youtube-d) LastVisualChange | linux1804-64-shippable-qr | cold fission webrender | 3,027.40 -> 2,965.24 | [Before](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FZrh7r45SS521LkXpOK5LVQ%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_youtube.zip)/[After](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FI6C0-x4wSOS7Kh163wxFdg%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_youtube.zip) |


Details of the alert can be found in the [alert summary](https://treeherder.mozilla.org/perfherder/alerts?id=39217), 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) may be backed out** in accordance with our [regression policy](https://www.mozilla.org/en-US/about/governance/policies/regressions/).

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

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