https://github.com/devtools-html/debugger.html/compare/release-19-3...release-19.4 Inspired by the huge performance impact here: - https://github.com/devtools-html/debugger.html/pull/5645 - https://github.com/devtools-html/debugger.html/pull/5648 15 seconds -> 3 seconds for loading pages built with webpack eval-mode and angular development mode

https://perfht.ml/2E4opg1 https://treeherder.mozilla.org/#/jobs?repo=try&revision=00b1f703f88cfe32a7e204f834f6122389f4a583 https://treeherder.mozilla.org/#/jobs?repo=try&revision=378f6dcf9ba75e278580cfe9095ca8cd9e2a7190

[Feature/Bug causing the regression]: https://bugzilla.mozilla.org/show_bug.cgi?id=1440550 [User impact if declined]: debugging react & angular apps will have 15+second load times in the debugger [Is this code covered by automated tests?]: yes [Has the fix been verified in Nightly?]: yes [Needs manual test from QE? If yes, steps to reproduce]: no [List of other uplifts needed for the feature/fix]: [Is the change risky?]: no [Why is the change risky/not risky?]:only affects the debugger [String changes made/needed]:

same as above

Unfortunately we need to land 19.4-align in order to align the modules inside of the bundle for the 19.4 bundle change. Fortunately, 19.4-align is just sorting the order of the modules so it is not a risky code change. 19.4 is applying two patches that previously landed in nightly in v23 (https://bugzilla.mozilla.org/show_bug.cgi?id=1446234) two weeks ago. It is also well tested by our mochitests. Here is a new profile with the improved performance (~4 seconds) https://perfht.ml/2E4opg1

Comment on attachment 8963643 [details] [diff] [review] rel-19.4-align.patch Review of attachment 8963643 [details] [diff] [review]: ----------------------------------------------------------------- LGTM, only moving bundles around.

Comment on attachment 8963744 [details] [diff] [review] rel-19.4-2.patch Glad to hear that the scary-big patch is just a giant no-op and this is the only functional change. Approved for 60.0b9.

https://hg.mozilla.org/releases/mozilla-beta/rev/28e4a26e9c48 https://hg.mozilla.org/releases/mozilla-beta/rev/623ccfdac45e

(In reply to Jason Laster [:jlast] from comment #2) > [Is this code covered by automated tests?]: yes > [Has the fix been verified in Nightly?]: yes > [Needs manual test from QE? If yes, steps to reproduce]: no Setting qe-verify- based on Jason's assessment on manual testing needs and the fact that this fix has automated tests.