Waterfox: (Mozilla 1118086) e10s in Waterfox 56.0.4.x: multi-process versus performance of the 'Select Device' menu/form/drop-down list at samsung-updates.com

[grahamperrin]

Origin: https://redd.it/7yglsz

Bugged

The menu (1,312 nodes?) to the left at:

• http://samsung-updates.com/device/?id=SPH-L720&details=Galaxy_S_4_Sprint

Reproduced with Waterfox 56.0.4_4 on FreeBSD-CURRENT.

[grahamperrin]

New profile, first run, safe mode, multi-process enabled:

• after loading the page, a delay of around six seconds between a click on the menu icon and appearance of the the menu.

Normal mode, multi-process disabled:

• no perceptible delay.

Normal mode, multi-process enabled:

• first attempt to restore the tab resulted in a crash
• second attempt, another crash
• third attempt, after loading the page, a delay of around four seconds between a click on the menu icon and appearance of the the menu.

(In my case, I'm tempted to treat the crashes as negligible.)

[AjvarXX]

I found it checking info for my phone but this trouble certainly exists on higher address domain without the need of preceded specific device page load:

http://samsung-updates.com/

I also checked on FF56 x86 new profile right now - same problem. Wonder if it's due to long list in that menu/form but still this huge lag deserves for further investigation, probably on bugzilla (Graham, Alex?).

[grahamperrin]

Firefox

5.8.0.2

browser.tabs.remote.force-disable true:

• appearance of the menu is instantaneous.

Multi-process enabled:

• a _split-second_ delay before appearance of the menu.

Bugzilla@Mozilla

https://bugzilla.mozilla.org/buglist.cgi?list_id=14018348&short_desc_type=allwordssubstr&short_desc=e10s%20menu&resolution=---&classification=Client%20Software&query_format=advanced&component=General&product=Firefox finds a handful of bugs, none of which are similar to this issue 442.

1063169 - (e10s-perf) tracking performance issues with e10s refers to numerous bugs. Speeding through the page source, I can't see anything like this issue.

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I'll run this comment past Mozilla's #firefox channel, ask whether they'd like it reported as a performance issue.

(With more than a thousand menu items, I guess that it'll be edge case.)

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Postscript, note to self: I didn't find 1118086 below because it's _Core_, and because my search terms included _menu_ and _form_ (neither _drop-down_ nor _list_).

[MrAlex94]

Thanks for all the research into this. Wonder if it’s worth implementing the WIP patch or wait until it’s properly fixed? The bug doesn’t seem to have moved in a month though.

[AjvarXX]

@MrAlex94 I would like to beta test this fix for sure. Mozilla team is insanely slow fixing something if it 'works' without a fix anyw. TBH I won't be surprised if it takes another year for them considering it's way less of a problem on latest FF builds.
Hmmm, on the other hand assignee clearly sais there i work to do further.

[grahamperrin]

I'm fairly ambivalent, not bitten by the bug in my environment.

Less personally, I should be wary of anything that might decrease accessibility.

[MrAlex94]

I've encountered it when selecting from a list of countries for example. While it's not critical, it's still a good quality of life improvement. I'll do a beta release of 56.1 anyway, and can be tested with that. If it doesn't work/breaks things I can revert the patch.

[MrAlex94]

I investigated this bug further - there are a lot of patches collectively made to fix this, which I think all made it to Firefox 59. I'm testing out the WIP patch, but so much is changing in it!

[grahamperrin]

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