1486303 - Lastpass severely slows down open new tab perf

Status: RESOLVED WORKSFORME

(WebExtensions :: Developer Outreach, defect)

Description

[henryfhchan]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0
Build ID: 20180823220048

Steps to reproduce:

[ (20 items) ].forEach(url => window.open(url, _blank));


Actual results:

Takes 10 seconds to open with Lastpass Addon enabled.
Takes 1 seconds to open with Lastpass Addon disabled.


Expected results:

Similar performance with Lastpass addon on or off.

Comment 1

[Hani Yacoub, Desktop QA]

Could you please provide some clearer steps to try to reproduce this issue?
Thanks.

Comment 2

[henryfhchan]

1. Open the developer console (F12) on any non-blank page.
2. Paste in:

[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20].forEach(url => window.open('https://www.msn.com/?id=' + url, '_blank');

When LastPass addon is enabled, opening tabs is visibly much slower.
When LastPass addon is disabled (via about:addons), opening tabs is very quick.

Attempt the above steps in private browsing mode for more drastic effects: you can see flashing purple with a lot of delay when LastPass addon is enabled, while the flashing purple is much quicker when the addon is disabled.

Comment 3

[henryfhchan]

Sorry, the code should read:

[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20].forEach(url => window.open('https://www.msn.com/?id=' + url, '_blank'));

Comment 4

[Hani Yacoub, Desktop QA]

Thanks for the details. I reproduced this issue on Firefox 61.0.2, Firefox 62.0b20 and on Firefox Nightly 63.0a1 on Windows 10 x 64.

Comment 5

[David Durst [:ddurst]]

LastPass has suggested that version 4.25.0 introduced a fix that may have improved this scenario. Can we re-verify with that version?

Comment 6

[henryfhchan]

Confirm fixed. The performance difference is not noticeable now.

(I also slowed my processor to 5%. The difference in loading was ~12 seconds (off) vs ~13 seconds (on) with 2 trial runs, pretty much just noise.)

Tested LastPass version 4.25.0.4 on Nightly 67 (build 20190216).