734946 - Disable incremental GC for Firefox 13

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: patch

I haven't made much progress in fixing the leaks related to bug 728686, and I think it's a bad idea to ship in the state we're in (where incremental GC gets randomly disabled). I think it would be better to disable incremental GC by default and then land the patch for bug 728686. That way, people who choose to opt in to incremental GC will have it on all the time.

Comment 1

[David Mandelin [:dmandelin]]

Do you think it would be useful to provide a tiny Jetpack add-on to enable IGC?

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/8cae4bde9534

(In reply to David Mandelin from comment #1)
> Do you think it would be useful to provide a tiny Jetpack add-on to enable
> IGC?

I don't know. about:config doesn't seem like much of a barrier to entry to me.

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Blargh. Tryserver shows *this* patch to be leaking. Has the world gone mad?

https://hg.mozilla.org/integration/mozilla-inbound/rev/6799a5e6912f

Comment 4

[Patrick Walton (:pcwalton)]

If we're in a situation in which our tests are telling us that incremental GC is required in order to stop Firefox from leaking, that's bad. I would think that this has to be fixed on Aurora before Firefox 13 can be released.

Since it looks like IGC is going to get uplifted (as I assume uplifts can't happen unless our trees are green), could we just land IGC leak fixes on Aurora?

Comment 5

[Shane Bundy]

https://hg.mozilla.org/mozilla-central/rev/8cae4bde9534

Comment 6

[Marco Bonardo [:mak]]

https://hg.mozilla.org/mozilla-central/rev/8cae4bde9534

Comment 7

[Marco Bonardo [:mak]]

Actually, looks like Bill backed this out.

Comment 8

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

https://hg.mozilla.org/mozilla-central/rev/a625b9ed671f

Relanded. Looks like the leaks were "fixed" in bug 734554. This sort of thing makes me hate Firefox.

Comment 9

[Daniel C]

Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120313 Firefox/13.0a1

about:config shows javascript.options.mem.gc_incremental;false yet about:support shows:

JavaScript
Incremental GC: 1

Is that a bug?

Comment 10

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

(In reply to Daniel Cater from comment #9)
> Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120313 Firefox/13.0a1
> 
> about:config shows javascript.options.mem.gc_incremental;false yet
> about:support shows:
> 
> JavaScript
> Incremental GC: 1
> 
> Is that a bug?

It's not a bug, although it's admittedly confusing. The about:support line is only showing whether incremental GC is permanently disabled due to binary add-ons. Incremental GC may also be disabled for other reasons (like the preference being off).

Comment 11

[Ioana (away)]

Verified as fixed on:
Mozilla/5.0 (Windows NT 6.1; rv:13.0) Gecko/20120318 Firefox/13.0a2
Mozilla/5.0 (X11; Linux i686; rv:13.0) Gecko/20120319 Firefox/13.0a2
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:13.0) Gecko/20120318 Firefox/13.0a2