Re: [PATCH] rust: alloc: add __GFP_HIGHMEM flag

[Miguel Ojeda]

On Fri, Jun 7, 2024 at 10:23 AM Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:
>
> Make it possible to allocate memory that doesn't need to mapped into the
> kernel's address space. This flag is useful together with
> Page::alloc_page [1].
>
> Rust Binder needs this for the memory that holds incoming transactions
> for each process. Each process will have a few megabytes of memory
> allocated with this flag, which is mapped into the process using
> vm_insert_page. When the kernel copies data for an incoming transaction
> into a process's memory region, it will use kmap_local_page to
> temporarily map pages that are being modified. There is no need for them
> to take up address space in the kernel when the kernel is not writing an
> incoming transaction into the page.
>
> Link: https://lore.kernel.org/all/20240528-alice-mm-v7-4-78222c31b8f4@xxxxxxxxxx/ [1]
> Signed-off-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>

Applied to `rust-next`, thanks!

Cheers,
Miguel