Re: [PATCH v3 1/2] kho: add support for preserving vmalloc allocations

Mike Rapoport
2025-09-15T16:36:33Z

On Mon, Sep 15, 2025 at 11:43:35AM -0300, Jason Gunthorpe wrote:
> On Mon, Sep 15, 2025 at 05:12:27PM +0300, Mike Rapoport wrote:
> > > I don't suppose I'd insist on it, but something to consider since you
> > > are likely going to do another revision anyway.
> >
> > I think vmalloc is as basic as folio.
>
> vmalloc() ultimately calls vm_area_alloc_pages() -> alloc_pages_bulk_node_noprof()
>
> KHO should have functions that clearly pair with the low level
> allocators struct page related allocators, alloc_pages(order),
> folio_alloc(), etc etc
>
> ie if you call this allocator X then you call this kho preserve, this
> kho restore, and this free function Y.
>
> Under the covers it all uses the generic folio based code we already
> have, but we should have appropriate wrappers around that code that
> make clear these patterns.

Right, but that does not mean that vmalloc preserve/restore should use the
public KHO APIs and avoid using internal methods.

> Jason

--
Sincerely yours,
Mike.