jQuery 1.5b1 is slower to remove elements than 1.4.2

[brad@…]

Adding and removing elements in 1.5b1 is noticably slower than in 1.4.2 (it was also slower in 1.4.3 and 1.4.4

 http://jsfiddle.net/F4TDA/1/

[rwaldron]

 http://jsperf.com/jquery142-vs-jquery-15b1

[anonymous]

Please see this related bug http://bugs.jquery.com/ticket/7338 This broke in 1.4.3

[rwaldron]

 http://jsperf.com/jquery142-vs-jquery-15b1/2

[rwaldron]

#8013 is a duplicate of this ticket.

[rwaldron]

The issue is traceable to the extra work being performed in cleanData()

[john]

Better perf test:  http://jsperf.com/jquery-remove

[john]

There were virtually no changes to cleanData in 1.5 - only the addition of some minor property lookups. There's really nothing that we can do to make this much faster.

[anonymous]

So this was slow enough for us that we could not upgrade from 1.4.2 ro 1.4.3 in our app. People complained when we switched. I really think that its important that things don't get noticeably slower between releases.

[snover]

How many elements are you removing from your page at once? Worst-case benchmarking on 1.5b in IE was something like 0.027ms per element. Based on the information and testcase provided, problems here would tend to suggest an architectural issue with your app rather than a problem in the lib; you would need to be removing tens of thousands of elements per second for the problem to be noticeable, unless there is a significant difference between the testcase and your app (like lots of bound events).

[anonymous]

So it was removing one element but there were a lot of elements inside of it. It was extremely poor on IE which forced us to revert to 1.4.2

[rwaldron]

Anonymous,

This ticket was addressed today at our weekly jQuery meeting, which is a public discussion on IRC int he #jquery-meeting channel.

During the discussion, this perf test:  http://jsperf.com/jquery-remove was created and we can agree that there is not a significant slow down.

If you could try 1.5b and report your findings, that would be very helpful to us.

[brad@…]

So we used the same test you provided on IE8 and its 61% slower

 http://www.screencast.com/users/JoeG816/folders/Jing/media/372a1b29-5cef-44a9-9c49-989ed1dc7d67

There is clearly a problem here - its the same performance issue that we began to see on 1.4.3.

[brad@…]

I would also add that the same test  http://jsperf.com/jquery-remove runs 38% lowers on FF 3.6 with 1.5 vs 1.4.2.