Re: [TECH TOPIC] Implementing malloc

On Thu, Jul 9, 2026 at 7:13 PM Matthew Wilcox <[email protected]> wrote:
>
> What I really don't want to see is a whole pile of Rust changes to
> accommodate having to pass GFP flags to memory allocations.  Would that
> be a better vehicle for the discussion?

Currently we already pass the GFP flags and support different allocators.

For context, initially we used a vendored `alloc` crate, because we
were trying to see if upstream could give us what we needed.

Then in 2024 (v6.10) we were able to drop the vendored copy by using a
workaround by Wedson that allowed us to pass the GFP flags and avoided
our reliance on upstream's allocator unstable feature:

  b6a006e21b82 ("rust: alloc: introduce allocation flags")

Later that year (v6.13), we couldn't wait much more, so we ended up
implementing our own `alloc` module and allocator support on our side
by Danilo:

  b7a084ba4fbb ("rust: alloc: add `Allocator` trait")

Cc'ing rust-for-linux and Danilo.

Cheers,
Miguel