Talos has detected a Firefox performance regression from push: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=7daaf289c085e05e0e4a0327a13748002fb467a0&tochange=22ba4f32a7afe64038a38cd2e1fc16ede661f9ab As author of one of the patches included in that push, we need your help to address this regression. Regressions: 535% tp5o_webext responsiveness windows7-32 opt e10s stylo 3.48 -> 22.08 216% tp5o_webext responsiveness windows10-64 opt e10s stylo 3.17 -> 10.04 Improvements: 2% tp5o_webext osx-10-10 opt e10s stylo 397.37 -> 388.89 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=12015 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 Talos jobs in a pushlog format. To learn more about the regressing test(s), please see: https://wiki.mozilla.org/Buildbot/Talos/Tests For information on reproducing and debugging the regression, either on try or locally, see: https://wiki.mozilla.org/Buildbot/Talos/Running *** Please let us know your plans within 3 business days, or the offending patch(es) will be backed out! *** Our wiki page outlines the common responses and expectations: https://wiki.mozilla.org/Buildbot/Talos/RegressionBugsHandling

:aklotz I see bug 1434489 caused some big regressions on our Windows OPT builds. The PGO builds don't seem affected. Can you please look over this performance drop?

I'm kind of surprised that Talos caught this given that the modules ping is so infrequent. Anyway, I see a problem that would affect perf, so I will fix that.

Comment on attachment 8957664 [details] [diff] [review] Move gathering of cert info off main thread Review of attachment 8957664 [details] [diff] [review]: ----------------------------------------------------------------- Looks good. One question about maybe using a utility function. ::: toolkit/components/telemetry/Telemetry.cpp @@ +908,5 @@ > #if defined(XP_WIN) > // Cert Subject. > + nsString* subject = mCertSubjects.GetValue(info.GetModulePath()); > + if (subject) { > + JS::RootedString jsOrg(cx, JS_NewUCStringCopyN(cx, subject->get(), Can you use froydnj's new ToJSString (from TelemetryCommon) here?

https://hg.mozilla.org/integration/mozilla-inbound/rev/017dbfcb23698b9484a4467221e86a0dca980326 Bug 1444361: Don't obtain cert subject info on main thread; r=chutten

I confirm this got fixed: == Change summary for alert #12047 (as of Fri, 09 Mar 2018 18:25:13 GMT) == Improvements: 74% tp5o_webext responsiveness windows7-32 opt e10s stylo 12.98 -> 3.33 67% tp5o_webext responsiveness windows10-64 opt e10s stylo 9.65 -> 3.19 For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=12047