As most of the QuantumBar architecture is currently stable, it seems a good time to do some Talos performance comparisons.

Bug 1523332 is likely the only one in the queue that I think may affect startup/window performance, however, it'd be good to get a comparison before and after that.

A first draft of this I did looked reasonable.

However I'm now doing one with pgo builds as well as opt:

• Comparison
• Try base
• Try pref-on

Mike/Joel, could you have a look at the comparison results here, do you think we need to take further action?

There's a few "medium" confidence issues, I don't know if we should worry about those.

tsvgx seems a bit like it could be a false-positive, since I'd don't know how we'd affect svg performance with something like the address bar.

tart seems like a possible issue, but it is only bad on Windows?

nothing jumps out as me as really problematic. in looking at the data on try and m-c for these tests I see almost every one of them is a bi-modal distribution which means that you are seeing a concentration on one mode vs the other- these all fall into natural patterns.

The only risk is if you made a bi-modal test become a single mode, worse case in the slower scenario. That would make the browser more deterministic though.

Nothing jumps at me as anything worth being concerned about, to be honest. The only ones that are surfacing as "important" are the TART test, which... makes no sense. I don't think it's worth spending the time trying to figure out why, to be honest.

I also wouldn't really worry about the sessionrestore tests - those measurements aren't very helpful - see bug 1531520.

The others aren't confident enough to be discernible from noise.

it may be interesting also to check with both pref and attribute switched, that is the final situation we'll have once QB is enabled by default.

Yeah, that was my next step, I think comment 5 should be considered invalid (I've marked it obsolete).

New builds:

• Comparison
• Baseline builds
• Pref-on builds

The additional results here look fine as well. I'm going to mark this as done, as I don't think there's anything more we need to do here.