1916803 - Investigate using a background thread to decommit memory

Status: NEW

(Core :: Memory Allocator, enhancement, P3)

Description

[Nicolas Silva [:nical]]

This would be a performance improvement. Upstream jemalloc has this feature.

Instead of running madvise directly in the thread where free is called, mark the page as "pending decommit" and let a background thread run madvise or VirtualAlloc.

It sounds simple on paper but I'm sure that getting the synchronization right for marking pages as pending/decommitted and dealing with whatever code needs to run after the last page of a chunk has been madvised is fraught with peril.
That said, there is prior art for it and I see madvise a lot in profiles (at least on linux), so getting them off the critical path would be valuable, assuming similar overhead is observed on Windows.