Jemalloc un-abandoned by Meta

I recently started using Microsoft's mimalloc (via an LD_PRELOAD) to better use huge (1 GB) pages in a memory intensive program. The performance gains are significant (around 20%). It feels rather strange using an open source MS library for performance on my Linux system.

There needs to be more competition in the malloc space. Between various huge page sizes and transparent huge pages, there are a lot of gains to be had over what you get from a default GNU libc.

One has to wonder if this due to the global memory shortage. ("Oh - changing our memory allocator to be more efficient will yield $XXM dollar savings over the next year").

Related. Others?

Jemalloc Postmortem - https://news.ycombinator.com/item?id=44264958 - June 2025 (233 comments)

Jemalloc Repositories Are Archived - https://news.ycombinator.com/item?id=44161128 - June 2025 (7 comments)

Few months back, some of the services switched to jemalloc for the Java VM. It took months (of memory dumps and tracing sys-calls) to blame the JVM, itself, for getting killed by the oom_killer.

Initially the idea was diagnostics, instead the the problem disappeared on its own.

Is there a concise timelime/history of this? I thought jemalloc was 100% open source, why is Meta in control of it?

Someone should tell Bryan Cantrill, he'd probably be ecstatic...

First impressions: LOL, the blunt commentary in the HN thread title compared to the PR-speak of the fb.com post.

Second thoughts: Actually the fb.com post is more transparent than I'd have predicted. Not bad at all. Of course it helps that they're delivering good news!

How is the original author making out in the new arrangement?

Jemalloc is used by android bionic libc library

Meta never abandoned jemalloc. https://github.com/facebook/jemalloc remained public the entire time. It's my understanding that Jason Evans, the creator of jemalloc, had ownership over the jemalloc/jemalloc repo which is why that one stopped being updated after he left.

Seems like they’d want to wait to commit until after the layoffs, right?

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And the Oscar for most mealy-mouthed post of the year goes to…