[Bug] Long delay when swiping to close tabs with many tabs open (~100 tabs)

[robsmith11]

We repurposed this issue to address from #11352 (comment)

After further use, it seems the slowdown is only obvious when a large (~100) number of tabs is open.

There's the same 1.5 second delay every time one swipes a tab to close it.

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The new tab from the latest Nightly is very slow. It opens quickly but then takes a full 1.5 seconds for the thumbnails to display, which is a major regression.

Device has Android 10 and a Kirin 980.

┆Issue is synchronized with this Jira Task

[robsmith11]

After further use, it seems the slowdown is only obvious when a large (~100) number of tabs is open.

There's the same 1.5 second delay every time one swipes a tab to close it.

[mcomella]

It opens quickly but then takes a full 1.5 seconds for the thumbnails to display, which is a major regression.

This should be addressed by #11185.

There's the same 1.5 second delay every time one swipes a tab to close it.

I will repurpose this issue to investigate and address this performance problem.

[mcomella]

Anecdotally, I saw this issue on Nightly 200609 (Preview channel) but not on Nightly 200610 (fennecNightly, fresh install) – I wonder if it's been fixed.

[mcomella]

Triage: we should determine at home many tabs does the delay become a problem.

[mcomella]

See also #11438

[mcomella]

I can no longer reproduce this on 200616 Nightly (I double-checked I could reproduce on 200610 and used the same installed data to do so). To be fair, I could never reliably reproduce this anyway. I suspect mozilla-mobile/android-components#7313 fixed the issue. Please reopen if you can still reproduce on the latest Nightly (and I'll keep an eye out for it too).

[robsmith11]

Yes, the delay seems to be fixed.

There's now a new problem: to switch tabs, one must always tap the thumbnail twice (first tap is ignored), but I guess that should be in a new issue.

[cadeyrn]

@robsmith11 This will be fixed in the next Nightly build.