Open Bug 1496899 Opened 6 years ago Updated 2 years ago

JS demo throttles if you navigate away from the page, and then return

Categories

(Core :: Layout, defect, P3)

defect

Tracking

()

Tracking Status
firefox-esr60 --- wontfix
firefox62 --- wontfix
firefox63 --- wontfix
firefox64 --- wontfix
firefox65 --- fix-optional

People

(Reporter: mayankleoboy1, Unassigned)

References

()

Details

(Keywords: nightly-community, perf, regression)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce:

1. Create new profile
2. Go to https://js1k.com/2016-elemental/demo/2552
It is fast
3. Enter google.com in the same tab, and go there
4. Press the back arrow to come back to the JS demo


Actual results:

Demo becomes very slow
Or atleast the animation slows down.


Expected results:

not so
on returning back, there is no CPU starvation. So this looks more of a throttling issue
Summary: JS demo slows if you navigate away from the page, and then return → JS demo throttles if you navigate away from the page, and then return
i can reproduce the issue on Win10 Nightly64.0a1 x64.

Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=e2009551c1be&tochange=2dfcc10c7270

Regressed by: Bug 1145439
Blocks: 1145439
Component: General → Canvas: 2D
Keywords: perf, regression
Happy to take a patch in nightly; if it seems low risk enough please feel free to request uplift to 65 beta.

Layout (or maybe DOM) is probably a better place to triage for now. Seth is no longer around who introduced the regression, but the regressing bug mostly modified features in those areas.

Component: Canvas: 2D → Layout

The priority flag is not set for this bug.
:dbaron, could you have a look please?

For more information, please visit auto_nag documentation.

Flags: needinfo?(dbaron)

CCing :tnikkel, it seems to me that we need to update Document::mVisibilityState when the document is restored from the BFCache.
Setting P3, it might be severer but it's been an issue since firefox 40.

Flags: needinfo?(dbaron)
Priority: -- → P3
Severity: normal → S3
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