uBlock Origin huge delayed startup begining from FF 144+ when javascript.options.baselinejit=false

[moakt3]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

After release Firefox 144 im notice that uBlock Origin start 8-10s after start browser itself. On Firefox 143 and lower it was 2-3s. I`m tired to wait when mozilla/raymond notice this and start digging. Especially this is noticeable when uBlock configured to suspend network activity until all filter lists are loaded. Mozilla something change beginning from the version 144 at work javascript.options.baselinejit. When user change this pref to false. Problem occurs. Firefox version 143 and lower never have this problem.

A specific URL where the issue occurs.

none

Steps to Reproduce

1: Open Firefox about:config
2: Change javascript.options.baselinejit to false
3: Open ublock and enable suspend network activity until all filter lists are loaded.
3: Close browser
4: Start browser

Expected behavior

After Firefox start ublock must start in 2-3 seconds after this.

Actual behavior

After Firefox start ublock startup have 8-10 seconds. User must wait 8-10 sec. after browser start to have possibilty use browser.

uBO version

1.68

Browser name and version

Firefox 144-145 (143 and lower not affected)

Operating System and version

Windows 11 / Debian 13

[gorhill]

ublock must start in 2-3 seconds after this

Normally uBO starts after less than a second, even 2-3 seconds is not normal. Please use Firefox profiler to gather profiling data to find out what is holding back uBO: https://profiler.firefox.com/

See https://profiler.firefox.com/docs/#/./guide-startup-shutdown for documentation on how to profile at Firefox launch.

[moakt3]

I can't do this. I use my own super-hardened user.js. Too many variables. But the problem that I described in this ticket is real and it's a javascript.options.baselinejit=false fault. Vanilla firefox v145 with javascript.options.baselinejit=false (and nothing more) show the same issue. Maybe this is help in understanding
https://bugzilla.mozilla.org/show_bug.cgi?id=1980830

[gorhill]

and it's a javascript.options.baselinejit=false fault

Then why open an issue here?

[moakt3]

I so many years disable javascript.options.baselinejit for privacy and security and now it conflict with uBlock and nobody care. Ok than. I'll wait 10 seconds every time for the filters to load. Thanks for help.

PS: Add to the extension description that user cannot change anything in about:config because this may affect on the work of the extension itself.

[gorhill]

Add to the extension description that user cannot change anything in about:config because this may affect on the work of the extension itself.

No need:

[ttmx]

Disabling JIT makes code run slower, this is expected and unavoidable.