1691361 - Tenured strings are put into the fixup list even if they have no children

Status: RESOLVED FIXED

(Core :: JavaScript: GC, enhancement)

Description

[Jon Coppeard (:jonco)]

When evicting things from the nursery we put them into a fixup list so we can go back and evict their children later. This is unnecessary for things with no children, such as many strings.

(There may be some interaction with string deduplication that means this has to happen, but it didn't look like it at first glance.)

This could speed up the case when we tenure a lot of strings because it means we won't have to build and traverse this linked list.

Comment 1

[Jon Coppeard (:jonco)]

Oh, and it looks like we do this for big ints, which never have children.

Comment 2

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1691361 - Do not add BigInts to the tenuring fixup list, since they do not have children

Comment 3

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1691361 - Only add strings with outgoing pointers to the tenuring string fixup list

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/db8812c0aed8
Do not add BigInts to the tenuring fixup list, since they do not have children r=jonco
https://hg.mozilla.org/integration/autoland/rev/f9dbe7d566bb
Only add strings with outgoing pointers to the tenuring string fixup list r=jonco

Comment 5

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/db8812c0aed8
https://hg.mozilla.org/mozilla-central/rev/f9dbe7d566bb