Re: [PATCH v4 03/20] mm: introduce linear_anon_page_index()

[David Hildenbrand (Arm)]

On 8/6/26 22:21, Lorenzo Stoakes (ARM) wrote:
> This function provides the anonymous equivalent of linear_page_index(),
> instead offsetting based on the anonymous page offset of the VMA.
> 
> It is valid only for anonymous or MAP_PRIVATE file-backed mappings, in
> other words CoW mappings.
> 
> For pure anon VMAs, this will be equal to linear_page_index().
> 
> Assert that both of these invariants are true In linear_anon_page_index()
> and implement the algorithm in __linear_anon_page_index().
> 
> Note that MAP_PRIVATE-/dev/zero mappings will satisfy vma_is_anonymous()
> but not fulfill this invariant, so when asserting this we check
> vma->vm_file to account for this.
> 
> We do not update callsites yet, so no functional change intended.
> 
> Also const-ify vma_is_anonymous() to make it compatible with the
> const-ified linear_anon_page_index().
> 
> While we're here, update linear_page_index() to be more succinct.
> 
> VMA userland tests are also updated accordingly.
> 
> Reviewed-by: Gregory Price (Meta) <gourry@xxxxxxxxxx>
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@xxxxxxxxxx>
> ---

Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

-- 
Cheers,

David