User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:92.0) Gecko/20100101 Firefox/92.0

Steps to reproduce:

Two choices. Bookmarks on the Bookmarks Toolbar, or bookmarks from the menu selections that include Bookmarks at the upper left of the browser. To get menus at upper left, click "Open Application Menu", then click and check Menu Bar. A list of menu selections are now at the top left of the browser. Browsing bookmarks from the Bookmarks on that list are laggy. Browsing bookmarks from the Bookmark Menu on the Bookmarks Toolbar are not. Again this does not happen in my two Windows 10 computers but it does in my two Windows 11 Beta computers. It is consistent.

Actual results:

I click on Bookmarks at the upper left of the browser and start scrolling up and down through my bookmarks and the selection highlight lags behind the cursor. Selection becomes sometimes frustratingly imprecise if I'm working fast, definitely not immediate. This does not occur with the bookmarks under Bookmarks Menu on the Bookmarks Toolbar.

Expected results:

What should have happened was both bookmark selection locations should behave the same. I have always preferred setting up and using the upper left Bookmarks, so this is not debilitating, but irritating. The lagging, by the way, only seems to occur with the bookmarks. I'm keeping the bar up there because I especially like to use History and Tools, and it is easy to get to those if at the top like that.

Could you please try to get a performance profile when the slowdown/lag happens? See profiler.firefox.com/, start profiling, reproduce the bug, then stop profiling. Sharing the profile should give you a url you can post to this ticket.

I'm new to this. Is this what you mean? This is the url with the performance profile I produced in my Firefox browser:

https://profiler.firefox.com/from-browser/calltree/?implementation=js&thread=c&timelineType=cpu-category&v=6&view=active-tab

Here's another one: https://profiler.firefox.com/from-browser/calltree/?implementation=js&thread=8&timelineType=cpu-category&v=6&view=active-tab

Those two were produced by scrolling the Bookmarks in the Menu Selection that appears at the top left of the browser (above the url search bar) after I've checked "Menu Bar" by right clicking "Open Application Menu" on the right.

This one is produced after I unchecked Menu Bar on the right, and I scroll the Bookmarks Menu from the Bookmarks Toolbar under the url search bar:

https://profiler.firefox.com/from-browser/calltree/?implementation=js&thread=e&timelineType=cpu-category&v=6&view=active-tab

I'm new to this. Is this what you mean? This is the url with the performance profile I produced in my Firefox browser:

In the Profiler window, look at the top right, there's a section "Upload Local Profile". It will do its thing and then give you an URL like: https://profiler.firefox.com/public/3wfg678je768jhi76n8mzppwa3xsxhr3msqh2dycxg. Paste that here.

(The links you gave only work on your local browser - we can't access them. My link is only an example, clicking it won't work)

That at least gives me some clue that's the right thing to do. Tried that yesterday and it seemed nothing happened because it takes awhile, long enough I stopped paying attention and went on to something else. This is what it produced from scrolling bookmarks from the Menu Bar at the top as described above, when the lagginess occurs..

https://share.firefox.dev/3avzA41

This one is with normal bookmark scrolling behavior from the Bookmarks Toolbar:

https://share.firefox.dev/3az2iRC

I think I may have discovered the problem. It may be related to the Windows 11 Beta edition I am/was using.

Yesterday one of my computers with Windows 11 did an update to Version: OS Build 22000.258. The previous ver, still on the computer I sent the previous performance profile from, is OS Build 22000.194.

I just tried doing the scrolling comparisons in Firefox on the machine with the 22000.258 build and noticed immediate improvement, and I got no lagging from either bookmarks locations. The results from the Menu Bar at the top are:

https://share.firefox.dev/3mPmYu9

From the Tool Bar I get:

https://share.firefox.dev/3oWhG2L

They look identical to me.

As soon as I can get the other computer to update its build to .258 I'll do a test and share the results. But my working hypothesis at the moment is the earlier Windows 11 build is the problem, not Firefox.

The severity field is not set for this bug.
:mak, could you have a look please?

For more information, please visit auto_nag documentation.

Please do not set severity on bugs, this is for triage owners & developers as part of the triage process.

From the profiles I see a high graphics cpu usage at 99% https://share.firefox.dev/2Z1ZRF1
I suspect this may be a dupe of bug 1724617 that is fixed in Firefox 94. If you had a chance to test Firefox Nightly on that machine, that could also help understanding if the issue is resolved.

Let me needinfo Matt so he can have a look at the profile and eventually confirm this is the same issue.

The fix for Bug 1724617 was related in Firefox 94 last week. Ren, have you upgrade to 94, and is this still an issue for you?

Mark, not an issue. Yes, it's fixed. I'm running Firefox 94.0.1. Thanks

Great, thank you, I'll mark it as a duplicate of that bug as it is most likely fixed as a result of that.