Open Bug 1961523 Opened 9 months ago Updated 4 days ago

Firefox constantly freezes

Categories

(Core :: Performance: General, defect)

Product:
Core
Component:
Performance: General
Version:
Firefox 137
Type:
defect

Tracking

()

Status:
UNCONFIRMED
Project Flags:
Performance Impact pending-needinfo

People

(Reporter: bluedzins, Unassigned, NeedInfo)

Details

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:137.0) Gecko/20100101 Firefox/137.0

Steps to reproduce:

For now this report looks vague I know, but simply I don't have concrete steps to reproduce this issue.

Previously I used I believe version 102 for quite some years and I didn't have such issue once (!). Then I was forced to upgrade FF (because expiring certificates), initially it was 136 and now 137, both have this issue.

My workflow is as follows:

  • I run several instances of FF, with multiple tabs in each -- those are "permanent" instances, online dictionaries, weather forecast, puzzle solver, AI sites, etc.
  • every day I run more FF instances with temporary tasks, like watching YT videos, StackOverflow, online stores, more or less I remember to close them after some time. For sure it is not the case I run 10000 of pages at the same time, and I didn't change my habits compared to 102 time. It could be I have 2 pages more, but not 10 times more

More or less, every week I have at least one freeze all of the sudden. Firefox simply becomes totally unresponsive and I have to kill it (all instances). It looks the current page (the one I observe freeze on) is irrelevant, it could be even my own, local, page.

I run openSUSE 15.3, exactly the same setup as before, I just upgraded FF, nothing else.

Unfortunately this is not really actionable at the moment.

Please try recording and sharing a performance profile:

  1. Go to http://profiler.firefox.com/
  2. Start recording and repeat the action
  3. Upload the profile and share the link here
Flags: needinfo?(bluedzins)

(In reply to Francesco Lodolo [:flod] from comment #1)

Unfortunately this is not really actionable at the moment.

Yep, I wish I have at least some meaningful steps.

  1. Start recording and repeat the action

By "action" do you mean some random thing, or should I keep recording for a week, and upload after the freeze?

  1. Upload the profile and share the link here

If the former, the link is: https://share.firefox.dev/3RqMllK

Flags: needinfo?(bluedzins)

You should start recording when you see Firefox freezing (assuming it will start).

This is not possible, because FF is frozen. It happened few seconds ago, so to clarify. Frozen program does not refresh, does not display actively its UI. So let's say I have two programs running, like Rider and Firefox. When FF is frozen when I switch to Rider I see Rider of course, when I switch to FF I see... Rider. I.e. it is not Rider technically speaking, but since FF does not show anything it looks (visually) as Rider, but it is window of Firefox really.

The only operation I can do is not with Firefox, but on Firefox -- killing it. But this kill comes from desktop, not from FF itself.

Not exactly sure how this can be debugged. Trying to move to Performances to see if folks have an idea.

Component: Untriaged → Performance: General
Product: Firefox → Core

Some facts. As this report goes, there were 3 freezes -- before opening this report, then 2025-04-21, and today (2025-05-02).

And today looked different than any before.

  • I tried to open/run new instance (window)
  • nothing happened
  • as it turned out, FF froze, I could not interact, but the page image was not lost, i.e. when I switch back and forth between windows, the relevant data was shown correctly
  • I decided to kill FF
  • the moment I did it, the new window/instance show up (by itself) greeting me with info I have new upgraded FF
  • I close it and run FF afresh
  • since this greeting was the last FF session, I could not restore the killed one

I am not sure if this means, there is a hint/indication the freezing is caused by FF upgrades (I don't know if there were any previously), or this is just a separate issue, but simply manifesting the same way by freezing.

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

For more information, please visit BugBot documentation.

Flags: needinfo?(bas)

Hrm, one noticeable thing in that profile is that there's a 250ms window where Firefox doesn't get scheduled and it cause quite a jank there. It's nothing quite as severe as you're describing, but do you often see shorter periods of unresponsiveness like that?

This type of short freeze suggests severe background activity or something like that.

But I'm not sure it's the same issue as you're describing.

Also ni?jld to see if this sounds at all familiar and could be related to updates and the forkserver.

Performance Impact: --- → pending-needinfo
Flags: needinfo?(bas) → needinfo?(jld)

In context of being responsive, it human terms (what my eye sees and what I feel) I would say Firefox is responsive for me (except for this issue). What is surprising for me, so far there was no more freezes. So the frequency of freezes is lower than in period between this jump-upgrade (from around v.102) to posting this report.

Another freeze. This time I could switch between FF instances, each was shown correctly (in sense of the image), but I couldn't interact with any of it.

My next suspect is network -- i.e. I suspect that maybe if there is a problem with the network, and FF tries to fetch something in this moment, there may be scenario of some infinite loop of some kind. I try to remember to check for sure if the freeze occurs at such case.

Few minutes ago another freeze. This time with FF upgrade plus connection lost. So maybe the network problem is the cause.

Another freeze. This time the network was on. Maybe there are two kinds of freezes causes? This time in all instances the window went black for the content, and menu, only the titlebar was shown and accurate. So when I switched from FF to FF, the entire window was non-existent, but title was and was correctly displayed.

Accidentally I clicked inside the content of FF (webpage) and the title changed (I hit some link). So maybe previously it was not complete freeze, I didn't check clicking on links, only actions like opening menu or scroling the webpage, but this requires content refresh.

This is not possible, because FF is frozen.

It should now be possible to control the profiler even if the Firefox UI itself is frozen:
https://profiler.firefox.com/docs/#/./async-posix-signal-control

(In reply to Gian-Carlo Pascutto [:gcp] from comment #13)

It should now be possible to control the profiler even if the Firefox UI itself is frozen:
https://profiler.firefox.com/docs/#/./async-posix-signal-control

Many thanks for the information. I tried to reproduce but without success.

For the first time the freeze occured while FF was in the background -- i.e. I did some things in FF, switched to another program, tried to switch back, but I couldn't because of the freeze.

Then I executed:

pgrep -f firefox | head -n 1
kill -s USR1 `pgrep -f firefox | head -n 1`
sleep 10
kill -s USR2 `pgrep -f firefox | head -n 1`

The first command was just to make sure the pid is found. It was. After last command I went to Downloads directory to check the outcome, but there was none, i.e. the Downloads directory is empty.

Another freeze. Update related (after restart FF showed info about upgrade done), and in the background -- last time I interacted with FF everything was fine, I switched away from it, and when I returned, it was frozen.

Another freeze, maybe update related, because update was pending. Another thing -- I could switch tabs within Firefox. When I clicked on tabs, the title of entire Firefox was changed to the title of the tab. The content of the tab was not refreshed though -- it was shown as it was frozen.

Another freeze, again the the update was pending.

Another one, when starting FF again it says it is installing new update, so the update was pending as well in this case.

Another one. This time I didn't notice any info about FF update.

Again, with update pending.

Again, without update pending.

Again, with update pending.

Another one, with update pending. This time it happened during opening local pdf, I managed to switch windows of Firefox few times while it was still opening, after a while Firefox become static last screen, so no matter to which window I switched I got this frozen one (in sense of image).

Again, no update pending.

Again, no update pending. FF froze when I was scrolling through YT comments and I think it is the moment, when the next "page"/batch of comments should be loaded.

Another one, probably with update pending (I am not sure, because what I saw after restoring session was info about Firefox Profiles).

Correction, it was an update (info about it was in another window, which I didn't see initially).

Again, no update pending.

Again, with update pending.

Again, with update pending.

Again, I don't see update pending.

Again.

Again.

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