5.46% Win8 Session Restore no Auto Restore regression on v.34 uplift to Aurora September 2, 2014



5 years ago
4 years ago


(Reporter: jmaher, Unassigned)


({perf, regression})

Windows 8
perf, regression

Firefox Tracking Flags

(Not tracked)


(Whiteboard: [talos_regression][MemShrink:P2])



5 years ago
This regression is frustrating because it isn't easy to pin down:

Looking on this graph, Mozilla-Inbound tracked Mozilla-Aurora until June 22nd (uplift v.32) where Aurora ended up slightly better, but there is no indication of why it is better based on the existing state of mozilla-central merging in.

This stays the same until August 21st where both branches see an improvement.  This is a parallel improvement and they both decline by the same amount.  Now when we uplift v.34 on September 2nd, Inbound stays the same and Aurora regresses (to finally be identical to Inbound).

The problem I have is why did this happen?  Was this some pgo issue (similar or related to bug 1029968)?  It isn't obvious what happened here.

For reference we have session restore [no auto restore] regressions on winxp, win7, win8, osx 10.6, linux32, linux64 as a result of this uplift:

more detailed list of alerts:

Comment 1

5 years ago
Another bug that landed was related to necko: bug 1041511 and bug 354493, this was backed out on inbound June 24th, it seems a bit late, but it also landed and contributed to confusion.

:Yoric, do you know of anything here why session restore is *regressed* and wasn't matched for the last 2 release cycles between aurora and central?
Flags: needinfo?(dteller)
Normally, neither bug 1041511 nor bug 354493 can have any effect on Session Restore. The only Session Restore-related bug I can think of that my have any effect on startup would be bug 1035557, landed on 34 ~2 weeks ago.

Now, do I read the graph incorrectly, or do I see improvements only?
Flags: needinfo?(dteller)

Comment 3

5 years ago
on september 2nd (the red line - aurora) goes up a bit, otherwise it is improvements.

Comment 4

4 years ago
we have already shipped this.
Last Resolved: 4 years ago
Resolution: --- → WONTFIX
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