1734051 - Fission's Amazon AWFY warm load time regression is mostly fixed, but doesn't match e10s with Olli's paint suppression tweaks

Status: RESOLVED WONTFIX

(Core :: DOM: Content Processes, defect, P3)

Description

[Chris Peterson [:cpeterson]]

After Nika's changes for bug 1731792 landed on 2021-09-29, Amazon AWFY warm load time improved a lot but did not reach e10s performance:

• Linux: https://arewefastyet.com/linux64/warm-page-load/overview?numDays=30&series=Firefox,Firefox-Fission
• macOS: https://arewefastyet.com/mac/warm-page-load/overview?numDays=30&series=Firefox,Firefox-Fission
• Windows: https://arewefastyet.com/win10/warm-page-load/overview?numDays=30&series=Firefox,Firefox-Fission

How much do we care? Nika improved Amazon warm load perf a lot (~470 to ~290 ms), actually beating Fission and e10s before the original regressions (~380 ms). The issue is that, in the meantime, Olli's paint suppression tweaks in bug 1731132 improved e10s's Amazon warm load perf but didn't help Fission.

Comment 1

[Jens Stutte [:jstutte]]

My take on this would be that we should look at a past baseline for e10s against current fission here and not compare two moving targets that are both influenced by our ongoing changes. I always understood our fission performance goal as a general "things should not become noticeable worse than they were before". I'd strongly suggest to fix a (past) release we want to benchmark fission against. But in the end this seems to be a product decision, so chaining in Mike.

Comment 2

[Mike Conca [:mconca]]

Both fixes are shipping in Fx94, so users upgrading from an older version of Firefox will see a net improvement of about 100ms. No reason to worry about this.

Comment 3

[Chris Peterson [:cpeterson]]

(In reply to Mike Conca [:mconca] from comment #2)

Both fixes are shipping in Fx94, so users upgrading from an older version of Firefox will see a net improvement of about 100ms. No reason to worry about this.

SGTM. I will resolve this bug as WONTFIX. We have more important performance issues to worry about.