Re: [RFC PATCH 1/5] mm: intorduce __GFP_UNMAPPED and unmapped_alloc()

[Song Liu]

On Thu, May 18, 2023 at 9:48 AM Kent Overstreet
<kent.overstreet@xxxxxxxxx> wrote:
>
> On Thu, May 18, 2023 at 09:33:20AM -0700, Song Liu wrote:
> > I am working on patches based on the discussion in [1]. I am planning to
> > send v1 for review in a week or so.
>
> Hey Song, I was reviewing that thread too,
>
> Are you taking a different approach based on Thomas's feedback? I think
> he had some fair points in that thread.

Yes, the API is based on Thomas's suggestion, like 90% from the discussions.

>
> My own feeling is that the buddy allocator is our tool for allocating
> larger variable sized physically contiguous allocations, so I'd like to
> see something based on that - I think we could do a hybrid buddy/slab
> allocator approach, like we have for regular memory allocations.

I am planning to implement the allocator based on this (reuse
vmap_area logic):

https://lore.kernel.org/linux-mm/20221107223921.3451913-2-song@xxxxxxxxxx/

Thanks,
Song

>
> I started on a slab allocator for executable memory allocations the
> other day (very minimal, but tested it for bcachefs and it works).
>
> But I'd love to hear more about your current approach as well.
>
> Cheers,
> Kent