Re: [PATCH v4 1/5] mm: Document lenient map_count checks

[David Hildenbrand (Red Hat)]

On 28.10.25 22:24, Kalesh Singh wrote:
> Add comments to the map_count limit checks in do_mmap() and
> do_brk_flags() to clarify their intended behavior.
>
> The use of a strict inequality ('>') in these checks is intentional but
> non-obvious. It allows these functions to succeed when the VMA count is
> exactly at the sysctl_max_map_count limit. This historical behavior
> accounts for cases where the operation might not create a new VMA, but
> instead merge with or expand an existing one, in which case the VMA
> count does not increase.
>
> These comments clarify the long-standing behavior and will help prevent
> future misinterpretation as an off-by-one error.
>
> Signed-off-by: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
> ---


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

--
Cheers

David