Meta’s renewed commitment to jemalloc

Building a software system is a lot like building a skyscraper: The product everyone sees is the top, but the part that keeps it from falling over is the foundation buried in the dirt and the scaffolding hidden from sight.

jemalloc , the high performance memory allocator, has consistently been a highly-leveraged component within our software stack, adapting over time to changes in underlying hardware and upper-layer software.

Alongside the Linux kernel and the compilers, it has delivered long-term benefits to Meta, contributing to a reliable and performant infrastructure.

Listening, Reflecting, and Changing
High leverage comes with high stakes.

On the spectrum of practical versus principled engineering practice, foundational software components like jemalloc need the highest rigor.

With the leverage jemalloc provides however, it can be tempting to realize some short-term benefit.

It requires strong self-discipline as an organization to resist that temptation and adhere to the core engineering principles.

In recent years, there has been a gradual shift away from the core engineering principles that have long guided jemalloc’s development.

While some decisions delivered immediate benefits, the resulting technical debt eventually slowed progress.

As a result of these conversations with the community, the original jemalloc open source repository has been unarchived.

We are grateful for the opportunity to continue as stewards of the project.

Meta is renewing focus on jemalloc, aiming to reduce maintenance needs and modernizing the codebase while continuing to evolve the allocator to adapt to the latest and emerging hardware and workloads.

Looking ahead, our current plan for jemalloc focus on several key areas of improvement: