We have detected a platform microbenchmarks regression from push: https://hg.mozilla.org/releases/mozilla-beta/pushloghtml?changeset=116c714b341eecf34d466907930ad2629f7d9b6a As author of one of the patches included in that push, we need your help to address this regression. Regressions: 30% Strings PerfStripCharsWhitespace linux32-nightly opt 1,029,160.83 -> 1,339,735.83 Improvements: 25% Strings PerfStripCharsWhitespace linux32-devedition opt 1,332,468.00 -> 995,651.33 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=8442 On the page above you can see an alert for each affected platform as well as a link to a graph showing the history of scores for this test. There is also a link to a treeherder page showing the jobs in a pushlog format. To learn more about the regressing test(s), please see: https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Automated_Performance_Testing_and_Sheriffing/Platform_Microbenchmarks

::dao I see you are the owner of bug 1367630. Can you look over this regression?

There's no way bug 1367630 can cause this regression. This test is testing low-level string behavior in gtest. Bug 1367630 changes the Firefox UI. The Firefore UI is not even running during this test. So if there's a regression here, its being blamed on the wrong push.

Looking at the numbers there, it almost looks like something mixed up the nightly and devedition numbers to me...

Again, there is no way a "tabbed browser" change could affect this test.

:bz Thanks for your insights. Will close this as INVALID, due to unreliability of the test on Linux platforms.