1364359 - Properly cleanup thread-local arenas

Status: NEW

(Core :: Memory Allocator, enhancement, P3)

Description

[Mike Hommey [:glandium]]

The arenas created in the jemalloc_thread_local_arena function added in bug 1361258 are leaked on purpose. This bug is about not leaking them and properly terminating them (they might not be empty when jemalloc_thread_local_arena(false) is called).

Comment 1

[Sean Feng [:sefeng]]

Can someone educate me the status of this bug?

I used moz_create_arena in bug 1377999, and I'd like know whether this is a blocker of my patch.

If I can't manually call moz_dispose_arena at the moment, will it be disposed sometime later?

Thanks

Comment 2

[Eric Rahm [:erahm]]

(In reply to Sean Feng [:sefeng] from comment #1)

Can someone educate me the status of this bug?

We think bug 1596300 will help out here, it's currently be worked on but is more of proof-of-concept right now.

I used moz_create_arena in bug 1377999, and I'd like know whether this is a blocker of my patch.

It really depends on how many you expect to create and whether or not you can reuse them. Mike probably has a better idea of the overhead of leaving them around.

If I can't manually call moz_dispose_arena at the moment, will it be disposed sometime later?

My understanding is they'll stick around until process shutdown. If these are limited to content processes this might not be a huge issue once fission is enabled.

Comment 3

[Mike Hommey [:glandium]]

What Eric said is accurate. At the moment, using moz_create_arena is not recommended except if the arena is meant to last until the end of the process. So for example, creating an arena for all DOM nodes in a process is fine, but creating an arena for all DOM nodes per page is not (with multiple pages per process).