Can anybody please provide a more detailed instruction to reproduce this? OS, browser, CPU, RAM, steps to reproduce?

The original reporter[1] states on her user page that she uses IE, and there's no more info.

[1] https://zh.wikipedia.org/w/index.php?title=Wikipedia:%E4%BA%92%E5%8A%A9%E5%AE%A2%E6%A0%88/%E6%8A%80%E6%9C%AF&oldid=27042994#.E8.BE.93.E5.85.A5.E6.A1.86.E7.BB.8F.E5.B8.B8.E5.8D.A1.E6.AD.BB

wulaquark wrote:

WIN8, Firefox 21.0, i5-3210M, 4G
When I was busy for something like Excel outside the browser, and then I turned back to the browser, clicked the textbox, WHOLE browser freezed few seconds. During this period, NOT just textbox freezing, the whole browser lost response.

Interestingly, this problem do not 100% appear. I guess it may be due to loading limited by network speed, or this input method program requested too many system resources.

This works for me. Please provide more specific profiling or something. Otherwise it will be very hard to get any progress on this issue.

Maybe more or less related to bug 49935 comment 16.

That bug is about freeze on page load, but "ULS is full of that kind of crappy code" per MatmaRex.

Duping per comment 5.

• This bug has been marked as a duplicate of bug 49935 ***