1623177 - Firefox is slow after several days of usage with many tabs

Status: RESOLVED WORKSFORME

(Core :: Performance, defect, P3)

Description

[Arne Babenhauserheide]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 IceCat/68.0

Steps to reproduce:

I’m using Firefox for browsing many different sites and for web development, loading Javascript intensive sites.

I have around 20-50 tabs open and Firefox uptime is up to several weeks without restart.

Actual results:

Firefox feels sluggish, actions take between 50% longer and 100% longer than with Chrome. Reloading takes longer. It is also slower than when I restart Firefox, restore the session, but only click the tab I’m working in.

I wondered about that speed, because that experience does not match speed tests like https://arewefastyet.com/linux64/overview?numDays=365
but these tests check newly started FF instances, not longterm-use instances.

Expected results:

Firefox should not decrease in speed when used for a long time with many tabs open.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:mikedeboer, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 3

[Sean Feng [:sefeng]]

When the slowness happens, can you use https://profiler.firefox.com/ to provide a profile for us to investigate it?

Comment 4

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Comment 5

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Comment 6

[Firefox Bug Husbandry Bot]

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Comment 7

[Firefox Bug Husbandry Bot]

The severity of these bugs was changed, mistakenly, from normal to S3.

Because these bugs have a priority of --, indicating that they have not been previously triaged, these bugs should be changed to Severity of --.

Comment 8

[Olli Pettay [:smaug][[e-mail]]]

Arne, have you perhaps tried a bit more recent Firefox. 68 is rather old.

Also, does about:memory hint about significant memory use?

Comment 9

[Arne Babenhauserheide]

Sorry for the slow response, I did not see notifications.

I see 2-4 GiB of memory use. I’ll attach a profile from a site that is 2x slower in FF 78 (icecat) than in Chromium.

Comment 10

[Arne Babenhauserheide]

Attachment: profile.json.xz

Comment 11

[Denis Palmeiro [:denispal]]

There's nothing out of the ordinary in the profile, if you're still experiencing this issue can you please collect a new profile and reopen the bug?