Re: [PATCH 0/4] drivers/net: replace __get_free_pages() with kmalloc()

[Paolo Abeni <pabeni@redhat.com>]

On 7/1/26 3:59 PM, Mike Rapoport (Microsoft) wrote:
> This is a (small) part of larger work of replacing page allocator calls
> with kmalloc.
> 
> My initial intention a few month ago was to remove ugly casts [1], but then
> willy pointed out that Linus objected to something like this [2] and it
> looks like more than a decade old technical debt.
> 
> Largely, anything that doesn't need struct page (or a memdesc in the
> future) should just use kmalloc() or kvmalloc() to allocate memory.
> kmalloc() guarantees alignment, physical contiguity and working
> virt_to_phys() and beside nicer API that returns void * on alloc and
> doesn't require to know the allocation size on free, kmalloc() provides
> better debugging capabilities than page allocator.
> 
> Another thing is that touching these allocation sites gives the reviewers
> opportunity to see if a PAGE_SIZE buffer is actually needed or maybe
> another size is appropriate.
> 
> For larger allocations that don't need physically contiguous memory
> kvmalloc() can be a better option that __get_free_pages() because under
> memory pressure it's is easier to allocate several order-0 pages than a
> physically contiguous chunk with the same number of pages.
> 
> And last, but not least, removing needless calls to page allocator should
> help with memdesc (aka project folio) conversion. There will be way less
> places to audit to see if the user was actually using struct page.
> 
> Also in git:
> https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git gfp-to-kmalloc/drivers-net-wireless
> 
> [1] https://lore.kernel.org/all/20251018093002.3660549-1-rppt@kernel.org/
> [2] https://lore.kernel.org/all/CA+55aFwp4iy4rtX2gE2WjBGFL=NxMVnoFeHqYa2j1dYOMMGqxg@mail.gmail.com/
> 
> ---

@Johannes: just an head-up, I assume this series will go via your tree
(despite the slightly misleading subj)

/P