This is something of a micro-benchmark, so I don't know whether this benchmark is pertinent. Still, here we go.

It is not a dom event test, but some odd js library test. But let me re-profile.

As far as I see (and the case was the same last time I profiled this) we spend by far most of the time in JS land. Stuff in and under event dispatch take 17%

Hmm, actually bug 561491 is a bit different. That is there js shows up more badly.

Are you also seeing a lot of time in Interpret? That shouldn't really happen anymore these days. I will take a closer look tomorrow.

So bug 561491 which is also about a jQuery event handling seems to spend lots of time in jit'ed JS, and here quite some time is spent in other JS stuff.

Mathias, I think we're running all kinds of unrelated scripts while running the benchmark: it looks like lodash.js (I think?) is dynamically creating functions with "with" statements for templating? Should this really happen while we're running the benchmark?

We fixed some issues here, looks like there's a bit more to do but I don't have the time right now.

Firefox 34 - 7600 op/s Chrome 39 - 8600 op/s Nightly 37 - 11500 op/s on Windows 7 - WFM

I tested the latest revision (http://jsperf.com/always-return-on-jquery-events/4) and get the result: Firefox 47.0 on Mac OS X 10.11 on with tag 262,789 on with class 272,596 Chrome 51.0.2671.0 on Mac OS X 10.11.3 on with tag 282,490 on with class 277,755 --- As a result I don't think Firefox, at least Nightly, really lost the battle. However, I must admit this is not a serious test because there are no accumulated data. Is this still an issue need more investigation, or we can just close it according to such result?

AFAIK, jsperf is perma-down (Mathias and JDD can correct me if I'm wrong). Unless someone else has a copy of the test-case in question... not much to be done here.

(In reply to Mike Taylor [:miketaylr] from comment #10) > AFAIK, jsperf is perma-down (Mathias and JDD can correct me if I'm wrong). It’s not perma-down — we’re working on getting a rewritten version of jsPerf up Real Soon Now™.

Benchmark unavailable..

Windows 10 results (jsperf is back) Nightly 58 (19-10-2017) (async stack disabled) on with tag 415,608 on with class 317,263 Chrome 61 on with tag 400,000 on with class 454,035

Linux amd64 Nightly 66.0a1 (2019-01-03) (64-bit) return on event 74,235 ops/s no return on event 74,439 ops/s on with tag 778,287 ops/s on with class 725,701 ops/s Chrome Version 72.0.3626.28 (Official Build) beta (64-bit) return on event 66,096 ops/s no return on event 66,342 ops/s on with tag 727,619 ops/s on with class 645,721 ops/s Looks very good to me. In fact Firefox is faster.

I get better results on Nightly/Windows than Chrome. I think we can close this one and open new bugs for other performance issues. WFM (since there isn't some particular fix here.)