Firefox finally plugs the leak

http://blog.mozilla.org/nnethercote/2012/05/07/update-on-leaky-add-ons/

by pbiggar • 14 years ago

227 107 14 years ago

blog.mozilla.org

Well, plugs _a_ leak. The Memshrink team has plugged an awful lot of leaks, and slimmed down an awful lot of code over the last year or so.

They've now hit the point where they're largely fixing bugs in add-on writer's code, rather than their own.

corin_2• 14 years ago

Is that actually the case, or is it that the leak they've fixed is related to the add-ons API? I've only really glanced at the patch discussion thread, and this isn't an area I understand all that well anyway, but the way it reads to me is as the latter - hopefully someone can explain why I'm either write or wrong on that, though.

AndrewDucker2• 14 years ago

So far as I understand, there was a change made which cut off a leak between add-ons and the tabs/windows they were attached to, so that closed tabs weren't being held in memory just because an add-on had a reference to them.

However, that change broke something in earlier versions of the Add-on SDK, which means that at least one Add-on was then leaking memory like crazy. Upgrading that add-on to the latest version fixed _that_ leak.

More here: http://blog.kylehuey.com/post/21892343371/fixing-the-memory-...

lillycat3• 14 years ago

They did both. The leak was in numereous add-ons code, but they were able to change the semantics of the API to remove all these leaks. But that breaks things in some edge cases, but that was deemed acceptable (one time fix in some extensions, mainly those using Jetpack needing to embed the latest versions).

pbiggar2• 14 years ago

Very true. There's been a massive amount of work put in by the MemShrink team. But it looks like they've found the holy grail this time; look at the numbers: 800MB vs 230MB. That's a big big deal.

diminish• 14 years ago

At my Linux firefox I am seeing better and better performance, thanks the team.

rrreese2• 14 years ago

This sounds great, I stopped using Firefox just over a year ago due to its fairly heavy memory usage. I usually run with 20+ tabs and even on a machine with 4GB of ram it was pretty unpleasant.

How are you current Firefox users finding the RAM usage, especially compared to Chrome?

lillycat3• 14 years ago

Since months (I would say Firefox 7), Firefox is better than Chrome when used with a lot of tabs.

robin_reala5• 14 years ago

I’ve just killed and restarted Firefox, then duped my current set of tabs over to Chrome (in-house jukebox using websockets, a slideshare presentation, couple of open Google Docs spreadsheets, a Pivotal tracker session, a couple of tabs of a local development project, Google Plus, and this HN thread). Totalling up ‘Real mem’ in Activity Monitor shows Chrome 18 using 735.4mb (of which 33mb is Flash). Firefox 13 (beta release to be fair) is coming in at 450mb (of which 65mb is Flash).

The internal memory measurements (about:memory) come out as 835mb resident for Chrome, and 324mb (of ‘explicit’, whatever that is) for Firefox.

I’m not using any extensions in Chrome. In Firefox I’ve got installed Firebug, FireFontFamily, FireQuery, Lastpass, PDF.js and QuickJava.

Edit: oops, missed cloning a tab with a video in over to Chrome. That explains the disparity in Flash, and you could probably expect to increase Chrome’s real mem usage a little had I not closed it already…

w1ntermute3• 14 years ago

> How are you current Firefox users finding the RAM usage, especially compared to Chrome?

I'm fairly sure that multiple studies have shown that Chrome uses more RAM than Firefox. But that's not what's important - all that matters is whether the browser appears snappy to the user. That's much more so the case with Chrome than it is with Firefox.

nextparadigms• 14 years ago

Chrome uses more memory, but for good reason. I think they load more stuff in RAM so the browser works faster, and there's also the sandbox security feature, which makes it so tabs don't share memory, so that must add quite a bit, too. That being said, I wouldn't mind if the Chrome team worked on optimizing RAM usage as well, if they aren't doing it already.

ExpiredLink3• 14 years ago

Informed users know that this 'memory usage' is caching, not leaking and that you can limit it if you really want.

BTW, History / Recently Closed Tabs is one of my favorite FF (only) features.

bmurphy• 14 years ago

Just because you have 16gb of memory doesn't mean you won't ever swap. Firefox is not the only application running on a computer. My working set is routinely over 7gb and I have 8gb on my laptop. A goldfish will grow to full its bowl. If I had 16gb, I know I could use it. Every little bit counts.

StavrosK• 14 years ago

Really? How? I'm currently coding and browsing the web and I'm only at 1 GB, out of 2. Sure, the VM isn't on, but that's still another 500 MB.

darklajid• 14 years ago

I don't understand what surprises you. The memory load depends in large parts on the work requirements, I'd guess.

2 weeks ago I went from 4 GB to 8 GB (still would love to have more) here at work, because 4 didn't cut it and lead to lots of paging.

  Visual Studio (often 2 or 3 instances, grabbing around 300-500 each)
  MS SQL Server
  IIS
  OCR Engines (depending on load)

With Windows 7 as host (already not a slim OS) this killed my productivity with 4 GB, especially if (to get back on topic) I opened my beloved Firefox...

samspot• 14 years ago

In my stack eclipse + tomcat hits up to 1300mb, plus leaky firefox with another 1gb, and windows and everything else at about 1.5gb. 4gb is barely enough.

LogicHoleFlaw• 14 years ago

I've easily burned through 8GB of memory when I'm crunching numbers on large-ish datasets in Octave. (And through twice that when I had a bug in said Octave code...)

barrkel• 14 years ago

Windows 7 sidebar.exe on my machine regularly wanders north of 4GB, until I restart it.

(It just shows a clock and my CPU core temperatures.)

ck2• 14 years ago

So every extension built with the SDK version before 1.6.1 is suspect.

That's a whole bunch of extensions.

khuey5• 14 years ago

That appears to be a bug in the approach we're using, and we think we have a fix for it.

mistermann• 14 years ago

This is great news. Any estimate on when these fixes might be released into a production version?

mbrubeck• 14 years ago

It actually turned out to be only SDK versions older than 1.4, which account for fewer than 500 add-ons (including only about 100 that are "fully reviewed" and are displayed in search results): http://bugzil.la/751466

And not all of those 500 add-ons will be affected, since it only affects add-ons using specific APIs from those old SDKs. And if the cause of that leak is fixed soon, then only users of Firefox Nightly builds will ever have been affected.

acqq• 14 years ago

According to the article, they plugged one leak but opened another, which appears as soon as you have a simple Add-on made with, so typically, Mozilla's own "Add-on SDK."

khuey5• 14 years ago

That's just a bug. It will be fixed (there's even a patch in https://bugzilla.mozilla.org/show_bug.cgi?id=752877)

wazoox3• 14 years ago

All of my machines have only 2GB of RAM. On the Linux boxen, I have absolutely no trouble running firefox with 50 tabs, OpenOffice and Gimp at the same time. I don't monitor FF memory usage, because there isn't any significant problem.

On the other hand on the MacBook I must restart FF regularly, else over 700MB of memory the application gradually slows down and "beachballs" regularly. I don't know what's wrong exactly, because I have all the same extensions.

cheald• 14 years ago

> All of my machines have only 2GB of RAM.

Out of curiosity, why? You can get 16GB of DDR3 for under $100 these days. The upgrade from 4GB > 16GB and an SSD were huge productivity boosters for me. When you stop worrying about memory management (from a consumer perspective), things are so much snappier.

kaolinite• 14 years ago

If he doesn't need it, why spend the extra money? :-) It may be cheap but if it's just going to sit there being unused then why bother at all?

wazoox3• 14 years ago

As I said, on my linux boxen I have no problem with RAM. They're fast and responsive. I have machines with up to 32 GB at hand (and dual octocore CPUs) but really, for a dev workstation a dual core with 2 gigs and 2 24" screens is more than enough to me, I never waited for gvim to open or anything.

OTOH my Mac with 2 GB feels slower everyday. Frankly, I simply decided that my next laptop will be a linux PC instead of a Mac, now that there are credible PC alternatives like the Asus Zenbook Prime (a few years ago Mac laptops were so far ahead it wasn't even worth trying).

zobzu3• 14 years ago

I observed similar results, even thus ive more ram on all boxes. Linux works very well. Firefox for Linux works very well.

On MacOSX it always feels like there's not enough ram. Including with Firefox, or maybe especially with Firefox.

yuvadam• 14 years ago

Mozilla has been making outstanding progress in decreasing Firefox's footprint. At least from what I can see on the beta channel, things are getting much better, every single day.

Props.

btipling2• 14 years ago

On Sunday, using my latest version of Firefox, I opened a single page loading it only once to check how it looked in Firefox. Then I forgot I had Firefox open for the rest of the day. Eventually my Macbook Pro became slow and looking at Activity Monitor I saw Firefox was taken hundreds of MB of RAM and just eating some 20-30% of CPU% just idling there.

Every time, Mozilla devs claim all the bad bugs will be fixed in the next version. I heard it for v2, for 2.5, 3, and 3.5 and now of course whatever crazy version number Firefox is on now. It still sucks, but now I don't care any more because now I have Chrome.

jlongster• 14 years ago

Something is obviously wrong there, and as seen in many other posts in this thread, that is not the case for most people these days.

astine• 14 years ago

I heard it for v2, for 2.5, 3, and 3.5 and now of course whatever crazy version number Firefox is on now.

And each time Firefox has gotten more stable than the last. It's pretty snappy now and I can run it for days on end with no problems.

Also this patch hasn't been applied yet.

rpearl2• 14 years ago

Every time I use Chrome, my Macbook Pro becomes slow and everything pages to disk. It's snappy when it starts, but in Chrome 20 or whatever crazy version number they're on now, there's still a lot of leaks. It's very frustrating.

But for some reason everyone has the impression that Chrome is both fast and uses less memory than Firefox, when the evidence points to the speed difference being anywhere from minimal to completely unnoticeable (I recently read a paper which suggested that Chrome's JIT optimizations have a negative effect on overall performance due to their expense). Furthermore, Firefox uses substantially less memory in general.

Extremely effective marketing on Google's part.

invisible2• 14 years ago

V8 is ACTUALLY fast and has been for years. I don't know how that could even be contested. Mozilla internally knows that v8 was/is fast and has been trying to beat them.

Chrome does use more memory if you have a ton of tabs open, but it also is still fast. I haven't noticed a substantial amount of memory leakage, but I guess that depends. Regardless, the memory leakage can be subdued by reopening a tab rather than reopening the app.

The marketing that Mozilla puts out is the problem, not Google's marketing.

http://arewefastyet.com/old-awfy.php

http://arewefastyet.com/

GeneralMaximus• 14 years ago

You're right, but most people will not notice Chrome's sluggishness because Google has worked very hard to ensure Chrome feels fast. That, and (in my experience) the fact that most Chrome users rarely go beyond 15-20 open tabs, make Chrome an overall better experience than Firefox for many people. In UX design, perception of speed counts almost as much as actual speed.

Erunno5• 14 years ago

IIRC both Google's and Mozilla's browser metrics showed that a vast majority of users (>90%) never open more than 5 tabs simultaneously. Chrome is optimized for this use case, both from a memory as well as interface perspective. So for most users it works very well, better than the competition I daresay. Unfortunately it tends to completely break down once you go too far out of its comfort zone (i.e. using many tabs). Unless you have immense amounts of memory (> 4 GB) the gigantic memory use will not only affect Chrome itself but also all other programs as the OS starts swapping their pages onto the hard disk (which have to be swapped back upon access which is slow). Additionally, the interface was clearly never intended to be used with too many tabs as it lacks any kind of tab overflow concept. And the interface starts to lack badly which for me is an indication that there are bottlenecks in the single browser process which handles the UI.

Firefox behaves far more gracefully in less regular use cases. With tab groups, switch-to-tab, don't load until selected and tab overflow I can easily have dozens of open tabs without affecting the performance of Firefox and the system too much while remaining quite convenient to use. Mozilla just has to improve the regular use case to be in a better competitive position. Once they've achieved this Firefox will be usable by a far wider range of possible users than Chrome.

Oh, and one of the reasons for Chrome's success (besides the sneaky bundling stuff) is probably the extremely convenient silent updater. I've installed Chrome on many computers which belong to people with little technical knowledge so I wouldn't have to bother with browser updates (users have no say in this) and outdated Flash versions (since it is bundled). Now, the latter reason wouldn't be necessary if Adobe wouldn't be such a bag of fail but that's another topic.

rickmb• 14 years ago

That's pretty much my experience, with one additional issue that really keeps me coming back to Firefox: Chrome doesn't handle sleep and wake-up well.

Ironically, one of the applications that suffers most from this is Google Apps. I'll have calendar, gmail and half a dozen spreadsheets and documents open, move to another room, re-open the Macbook and Chrome dies on all the tabs. Firefox has no problem with this.

krakensden• 14 years ago

On Linux and Windows, Chrome used to be significantly faster. Especially on Linux, where Firefox was honestly miserable to use. Now it's just a little bit faster to start up, and is just a little bit snappier.

The OS X ports of both browsers are a little bit infamous for being iffy, aren't they?

luser0012• 14 years ago

Almost every Firefox thread has a comment like this. I'm no Firefox expert, but I use it a lot. The most common question asked in response is:

   What extensions are you running? Can you disable some of them.

I run ABP, Ghostery, HTTPS Everywhere, Firebug. No probs wrt memory.

Wrt CPU: are you sure you didn't have flash videos playing in a few of the tabs? :)

Btw, in my limited experience the meme that Chrome uses less memory is false. It just splits it across many processes (and IIRC this was shown recently using graphs and everything) making it harder to infer in something like Windows Task Manager.

Except wrt startup time, Firefox feels as fast (or faster) than Chrome.

Firefox needs to work on two things:

1. Raw startup time

2. speed up loading of awesomebar info after startup: even a simple-minded thing like write out the entire file under a new name every few days will probably defragment the file. it seems like that file gets heavily fragmented leading to long delays to load it. I might be wrong about the root cause.

YMMV.

kibwen5• 14 years ago

For #2, try Vacuum Places Improved:

https://addons.mozilla.org/en-US/firefox/addon/vacuum-places...

It gives you a button to defragment your Places database, which might greatly speed up your awesomebar. You can also set it to run automatically at startup after the browser has been restarted X times (by default X is 50, and I'm not sure that I restart Firefox 50 times in a year, so you may want to reduce this).

btipling2• 14 years ago

As I mentioned, I only opened a single page. This page had no JavaScript. I only loaded it once. I only have Firebug, 1password and xmarks installed. But it doesn't matter, Firefox is a slow memory hog, it has been since 1.5.

jlebar• 14 years ago

> Every time, Mozilla devs claim all the bad bugs will be > fixed in the next version.

Wait a second. Did we say this anywhere this time? Read tfa; does it claim to have fixed "all the bad bugs", or even all the memory leaks?

The headline to this article says that. Sure. But Mozilla did not.

pbiggar2• 14 years ago

Hey, I wasn't trying to oversell this with the headline, but it really seemed like this was the memory leak that had been patched. (I especially wasnt trying to undermine the rest of the awesome work that you guys at Memshrink is doing)

joelthelion• 14 years ago

I wonder if the problem isn't Mac OS specific. I've never seen anything even remotely similar on any of my linux computers.

driverdan2• 14 years ago

I applaud the MemShrink team for their effort in finally fixing FF. Forgive my ignorance but why are these leaks possible in the first place? Shouldn't the browser manage and constrain plugins (sandbox?) to prevent issues like mem leaks from even being possible? I understand the high level description of the patch but I don't understand why this wouldn't have already been part of FF's plugin management system. It seems like a pretty basic and core concept.

mccr82• 14 years ago

There is a tradeoff between how powerful addons can be and how much they are sandboxed. Firefox errs on the side of letting the user control their browsing experience. This patch reins in addons a tiny amount to eliminate a very common source of addon leaks.

kibwen5• 14 years ago

Remember that Firefox was originally intended as a minimalist platform, with the expectation that users would use its extension mechanism to build it up according to their needs. As a result, Firefox's extension mechanism is quite liberal. The upside is that its extensions are capable of much more than, for example, addons in Chrome. The downside is that extensions are responsible for much more, and can touch basically any part of the program (which is why powerful addons are so prone to breaking with new versions of Firefox: they're effectively targeting an unstable API).

Chrome addons are less prone to breakage and mischief, because Chrome addons target a stable API with a limited set of functionality. Firefox introduced just such an API last year, called the Jetpack API (it may have been renamed since then). You can tell if an extension is using the Jetpack API if it doesn't require a browser restart to install.

driverdan2• 14 years ago

I assumed it was something along these lines, thanks for making it clear.

Erunno5• 14 years ago

"You can tell if an extension is using the Jetpack API if it doesn't require a browser restart to install."

Not necessarily. "Traditional" extensions can be extended to support being restartless as well if they implement the necessary hooks.

srean3• 14 years ago

This is great news and may finally push me into upgrading FF on my depleted box. Despite all the grumblings about FF's memory issues, it is the (only) full featured browser that works for me, not Chrome.

There are a few reasons for that. (1) There's no tab abuser worse than me. I have hundreds of them around (I have commented before, why I have it that way) (2) I do all my browsing from a (battery less) laptop with 512 MB of RAM. (3) I do not close my browser for months on end. On top of that I expect that I should be able to do my usual editing etc while I have the browser open.

For this very corner'est of corner cases, if I use Chrome, my box goes into a fetal position and dies. However, and kudos to FF 3.6, (yeah 3.6!) my laptop works great, no problem at all. I have flashblock, no script, bar-tab, memory fox, bunch of greasemonkey scripts (to fix google's layout, and give github and bitbucket a dark theme) and have tweaked FF's cache settings.

On a more performant box I am on FF-11, but have never upgraded on the other, fearing that the new FF assumes (not unreasonably) the box to have more memory.

mburns• 14 years ago

Why not spend a few dollars and double or quadruple your memory?

srean3• 14 years ago

I can send you my routing number if you have a few to spare :)

But a larger point is that I disagree with the trend of using more hardware for doing less but taking the same quantum of running time , especially so when there are easy non-onerous alternatives. Much that anyone may want to manage my expenses, doing it this way frees up money that I can spend elsewhere, where I am more keen.

This box of mine is not worth spending more money over, but useful enough that its a loss if I junk it.

aboodman• 14 years ago

In the post, the author addresses this:

...what if the user has a high-end machine with 16GB of RAM? Then paging isn’t an issue. But this improvement will still be a big deal on such a machine. This is because garbage collection and cycle collection cause pauses, and the length of the pauses are roughly proportional to the amount of live heap memory. (Incremental garbage collection will soon be enabled, which will result in smaller garbage collection pauses, but there are no plans for incremental cycle collection and so cycle collection pauses will still be relevant.) So even on high-end machines with lots of RAM, leaks can greatly hurt browser performance.

bconway• 14 years ago

I would love to go back to Firefox as my full-time browser, but I have handful of showstoppers that I haven't found a good way around:

- Inability to run a private browsing window at the same time as my regular browsing. - No desktop notifications. (There appears to be an outdated and/or unmaintained add-on for this?) - No working equivalent of a few app-specific extensions (Google Voice button, Google+ +1 button, Google Reader inline previews)

archivator• 14 years ago

If you create a second profile, you can start a private browsing session in it without it interfering with the main profile (not as good as Chrome's approach but to me it's just another launcher in the panel).

No idea about the other ones though.

FreeFull4• 14 years ago

How bad of a tab abuser are you? I can easily reach over 450 tabs. It helps that since Firefox 4, there is an option that doesn't load all tabs when you start Firefox up, but instead only loads the tabs as you switch to them. Tabs that haven't been loaded don't seem to have much footprint at all, so I tend to build up rather a lot of them.

Herring2• 14 years ago

How do you guys manage your tabs? I have ~100 and I sometimes feel like I'm drowning. That option you mentioned really helps.

pudquick• 14 years ago

Unfortunately, that works only if you're frequently closing and reopening Firefox.

I tend to leave it running all the time.

For me, I went with an Add-On named "TooManyTabs": https://addons.mozilla.org/en-US/firefox/addon/toomanytabs-s...

"To SPEED UP your Firefox, when a tab is added to TMT, it is unloaded from browser and its tab state & history are stored in TMT. When you click on a tab, the tab is opened again from disk cache, with tab state & history restored if available; (Please note that the memory freed varies and is subjected to different websites.)"

When I come back to the browser, if I haven't used it in a while, I send all the currently open tabs to a new row which unloads them from browser memory. Then, when I get a chance, I go back to the various rows and clean out the tabs I don't want to keep and the condense them down to the "real gold".

Once I have what I want to keep, I restore the tabs and then use another Add-On named "CopyAllUrls": http://www.plasser.net/copyallurls/

This one lets you generate, to the clipboard, any number of markup formats (including HTML) containing the details of all the tabs you have open (with configurable options for details).

I tend to paste this comment into Gmail with a special tag (myaddress+selfnote@gmail.com) which triggers a "mark as read" filter. I do this because all I need is web access, regardless of the browser, and I can get access to all my bookmarked content with the power of Google Search. In addition, on my desktop and mobile phone devices, the mail is automatically sync'd to it for me to carry around for instant access.

skeletonjelly2• 14 years ago

Is this an about:config setting? Can you please share?

systematical• 14 years ago

Better late than never, but you leaked more than just my system memory...you leaked your own market share.

Erunno5• 14 years ago

Yeah, hopefully this will not go down in history as another too little, too late effort. Firefox still has a sizable market share of about 20%-25% (depending on the source) so Mozilla can still flex some muscle to keep the web open. I dread the day when only cooperate players are left to decide about the future of web technologies.

I wonder how the situation would look today if the MemShrink and Snappy projects had been started in 2009 or 2010 at the latest. My gut feeling tells me that the loss of market share and especially mindshare wouldn't have been as dramatic as it is today. Oh well, I'm happy that Mozilla apparently got their act together and taking the competition more seriously. Right now it's fun looking forward to each next Firefox version. :-)

zobzu3• 14 years ago

Its hard to say. Bu where Chrome made the most impact is probably not the geeky community, but mr everybody.

And how? => link on google.com telling you have to get Chrome => bundling+force install+defaulting Chrome when updating acrobat reader, flash, etc, even from Firefox or IE.

Both work fine as long as Chrome is a decent browser (and Chrome is a very decent browser that's for sure)

They stopped the later and still do the former (it doesn't necessarily show up in all situations so your mileage will certainly vary), any time you go on Google.com with any browser. At least the former is not morally wrong, but it certainly has a huge impact due to their near monopoly on search, and people believing that Google is the Internet and if Google says something, they should probably do it.

I don't think Mozilla could beat neither of those 2 points, even thus they could have lowered the overall impact by doing things better (especially their switch to 6 weeks release without having silent update/auto addon compat, that one was just plain dumb).

marklindhout• 14 years ago

Pfew... 230 megabytes for a running browser. Not long ago that was all my workstation had!

goggles99• 14 years ago

Almost an identical title to this one 10 months ago... SMH

Mozilla May Have Plugged Firefox's Memory Leak Once and For All Posted 07/06/2011 at 8:36am | by Paul Lilly http://www.maximumpc.com/article/news/mozilla_may_have_plugg...

Firefox finally plugs the leak

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