RepoJournal
Google

Google

JAX, the GenAI SDK, and the Cloud libs - Google's open source layer

Keep up with Google in about 3 minutes a day: what actually shipped — the commits, pull requests, releases, and security advisories that matter.

One email a day. Unsubscribe in one click.

Pick a date

Topics: AI / ML Python Full archive →

The Wire · Showcase

JAX REMAT3 OVERHAUL CUTS MEMORY PRESSURE WITH SELECTIVE OFFLOADING

By RepoJournal · Filed · About Google

1 person shipped this

JAX is shipping a fundamental redesign of its rematerialization system that lets you offload specific activations to slower storage during training, reclaiming GPU memory without the checkpointing tax.

The remat3 refactor hits production with two major pieces: support for save_and_offload_only_these_names [1] and offload_dot_with_no_batch_dims [2], both defunctionalizing previous approaches into dataclass policies. The first lets you name exactly which residuals get device_put to offload storage on the forward pass and restored on the backward pass. The second does the same for matrix multiplications without batch dimensions, offloading their outputs while rematerializing any batched dots as before. This keeps the remat2 functional interface intact [1] so your existing code doesn't break. Meanwhile, custom_vjp3 now handles unhashable nondiff_argnums [3], closing a gap that was blocking some VJP patterns. The wins here are real: you trade slow storage I/O for GPU memory headroom on large training runs without recomputation overhead.

One email a day. Unsubscribe in one click.

Action items

References

  1. [1] [remat3] support offloading via save_and_offload_only_these_names google/jax
  2. [2] [remat3] support offloading via offload_dot_with_no_batch_dims ↗ google/jax
  3. [3] [custom_vjp3] handle unhashable nondiff_argnums in custom_vjp3 ↗ google/jax

Quick answers

What shipped in Google on July 6, 2026?
JAX is shipping a fundamental redesign of its rematerialization system that lets you offload specific activations to slower storage during training, reclaiming GPU memory without the checkpointing tax. In total, 7 commits and 4 pull requests landed.
Who contributed to Google on July 6, 2026?
1 developer shipped this update, including mattjj.
What were the notable Google updates?
[remat3] support offloading via save_and_offload_only_these_names, [remat3] support offloading via offload_dot_with_no_batch_dims, and [custom_vjp3] handle unhashable nondiff_argnums in custom_vjp3.

More from Google

Daily updates, in your inbox

Follow Google

Keep up with Google in about 3 minutes a day: what actually shipped — the commits, pull requests, releases, and security advisories that matter.

or

One email a day. Unsubscribe in one click. Read a past issue →

Elsewhere on the wire

Want every project, not just this one?

We use privacy-friendly analytics (Google Analytics, IP-anonymized) to see which pages help readers. No ads, and we never sell your data. See our Privacy Policy.