999926 - unused-gc-things can get pretty big and never seems to be collected/released

Status: RESOLVED DUPLICATE of bug 989379

(Core :: JavaScript: GC, defect)

Description

[Katelyn Gadd (:kael)]

I've got a handful of tabs open that are pretty light on content. It seems like over time while I navigated around in them, they accumulated unused-gc-things. GC/CC/Minimize memory usage don't seem to release them. (I'm not entirely sure what this category represents).


│    ├──102.96 MB (07.47%) -- top(http://www.mangahere.com/manga/xxx/v05/c018/18.html, id=133)
│    │  ├───69.08 MB (05.01%) -- js-zone(0x2168f800)
│    │  │   ├──53.49 MB (03.88%) ── unused-gc-things
│    │  │   ├──14.24 MB (01.03%) ++ strings
│    │  │   └───1.35 MB (00.10%) ++ (6 tiny)
│    │  └───33.88 MB (02.46%) ++ active
│    ├──100.38 MB (07.29%) -- top(http://www.mangahere.com/manga/yyy/c005/2.html, id=135)
│    │  ├───66.30 MB (04.81%) -- js-zone(0x21771c00)
│    │  │   ├──50.73 MB (03.68%) ── unused-gc-things
│    │  │   ├──14.24 MB (01.03%) ++ strings
│    │  │   └───1.33 MB (00.10%) ++ (6 tiny)
│    │  └───34.08 MB (02.47%) ++ active
│    ├───97.75 MB (07.10%) -- top(http://www.mangahere.com/manga/zzz/v01/c001/6.html, id=137)
│    │   ├──63.61 MB (04.62%) -- js-zone(0x21775000)
│    │   │  ├──47.92 MB (03.48%) ── unused-gc-things
│    │   │  ├──14.23 MB (01.03%) ++ strings
│    │   │  └───1.46 MB (00.11%) ++ (6 tiny)
│    │   └──34.14 MB (02.48%) ++ active

I think 50mb of unused-gc-things total would make sense, but per-tab is a bit unreasonable. Every one of these tabs that I've actively browsed through has this much. (It's possible this page's JS has some sort of leak, but that would surprise me given that it's a simple image browsing site with some trivial event handlers.)

Overall stats:
507.52 MB (100.0%) -- js-main-runtime-gc-heap-committed
├──297.26 MB (58.57%) -- unused
│  ├──297.26 MB (58.57%) ── gc-things
│  └────0.00 MB (00.00%) ++ (2 tiny)
└──210.27 MB (41.43%) -- used
   ├──197.74 MB (38.96%) ── gc-things
   ├────9.34 MB (01.84%) ── chunk-admin
   └────3.18 MB (00.63%) ── arena-admin

This is mostly relevant given
1,777.24 MB ── private
1,890.65 MB ── resident
2,852.92 MB ── vsize

Probably time to restart this firefox.exe. Wish I didn't have to do that so often.

Comment 1

[Nicholas Nethercote [inactive]]

I'll just dup this to bug 989379, which is about this very same topic.