Bug: 10.89 - 10.61% facebook LastVisualChange / facebook LastVisualChange (OSX) regression on Mon September 2 2024
Status: RESOLVED
Priority: --
Resolution: DUPLICATE
Created: 2024-09-06 10:03:18+00:00
Resolved: 2024-09-11 15:54:47+00:00

Perfherder has detected a browsertime performance regression from push [a1203aa11e65fbab12d63076469cb818d4656089](https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=a1203aa11e65fbab12d63076469cb818d4656089). 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** | 
|--|--|--|--|--|--| 
| [11%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779400,1,13)  | [facebook](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#facebook-d) LastVisualChange | macosx1015-64-shippable-qr | fission warm webrender | 559.36 -> 620.28 | [Before](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FQzTYYCm3TQKmUl4MoJ39Qg%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_facebook.zip)/[After](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FGlZFIOAnQxiuCbOOc06RZQ%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_facebook.zip) |
| [11%](https://treeherder.mozilla.org/perfherder/graphs?timerange=1209600&series=autoland,3779400,1,13)  | [facebook](https://firefox-source-docs.mozilla.org/testing/perfdocs/raptor.html#facebook-d) LastVisualChange | macosx1015-64-shippable-qr | fission warm webrender | [555.72](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/QzTYYCm3TQKmUl4MoJ39Qg/runs/0/artifacts/public/test_info/browsertime-results.tgz) -> [614.71](https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/GlZFIOAnQxiuCbOOc06RZQ/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%2FQzTYYCm3TQKmUl4MoJ39Qg%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_facebook.zip)/[After](https://profiler.firefox.com/from-url/https%3A%2F%2Ffirefox-ci-tc.services.mozilla.com%2Fapi%2Fqueue%2Fv1%2Ftask%2FGlZFIOAnQxiuCbOOc06RZQ%2Fruns%2F0%2Fartifacts%2Fpublic%2Ftest_info%2Fprofile_facebook.zip) |


Details of the alert can be found in the [alert summary](https://treeherder.mozilla.org/perfherder/alerts?id=1977), 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 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.

You can run these tests on try with `./mach try perf --alert 1977`

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