Open Bug 1348848 Opened 6 years ago Updated 2 months ago

FF52 Performance Regression

Categories

(Core :: Layout, defect, P3)

52 Branch
defect

Tracking

()

Tracking Status
firefox-esr45 --- unaffected
firefox52 --- wontfix
firefox-esr52 --- affected
firefox53 --- wontfix
firefox54 --- wontfix
firefox55 --- wontfix
firefox56 --- wontfix
firefox57 --- fix-optional

People

(Reporter: irena.kull, Unassigned)

References

Details

(Keywords: perf, regression)

Attachments

(2 files)

Attached file FF52.zip
User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.30729; .NET CLR 3.5.30729; rv:11.0) like Gecko

Steps to reproduce:

Extract the attachment and open the index.html file in FF52 and measure time to load


Actual results:

Time to load is around 10s


Expected results:

Expected time to load is a few ms
Roughly regression range is between 46 and 47.
Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=5f6c9ac2919a7592af3e24c9142cac39dd79a1d5&tochange=4e08f29820a35936be6142b86350318e3246633d

Regressed by:
4e08f29820a3	Boris Zbarsky — Bug 1263845. When a parent changes from auto height to non-auto height or vice versa, a percentage height non-block child needs to realize it's doing a vertical resize. r=dbaron
Blocks: 1263845
Status: UNCONFIRMED → NEW
Component: Untriaged → Layout
Ever confirmed: true
Keywords: perf, regression
Product: Firefox → Core
Right, that fix makes us do a relayout in more cases...  I'll look at this testcase to see whether we can avoid them in some cases in it.

Alice0775, do you mind requesting needinfo from me in the future on regressions from my patches, so they don't get lost in the other bugmail?
Flags: needinfo?(bzbarsky)
(In reply to Boris Zbarsky [:bz] (still a bit busy)
> 
> Alice0775, do you mind requesting needinfo from me in the future on
> regressions from my patches, so they don't get lost in the other bugmail?

I will do.
OK, so this was slow before bug 1209994, then was sped up when we introduced bug 1263845 (which did not perform relayout in some cases when it needed to happen), then slowed down again when we fixed that.

I have various ideas for how we could make the table case specifically faster here, but the more general solution is fixing bug 1351924.  If that gets stuck, then I can probably implement something specific here.
Depends on: 1351924
Flags: needinfo?(bzbarsky)
It's too late for 54. Mark 54 won't fix and see if we can fix it in 55.
Priority: -- → P3
Severity: normal → S3
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