1660737 - Consider compacting malloc'd memory

Status: NEW

(Core :: JavaScript: GC, task, P3)

Description

[Jan de Mooij [:jandem]]

Certain malloc allocations (slots, elements, string characters with some work) could be moved by compacting GC to avoid fragmentation, if jemalloc offered an API for this. This could work better if movable allocations used their own jemalloc arena.

This is just an idea -- I don't know how big of a problem malloc fragmentation is for us in practice these days, especially with Fission.

Comment 1

[Paul Bone [:pbone]]

Bug 1656155 will tell us about jemalloc fragmentation, but it won't tell us how much of this is for memory the JS engine is using.