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

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@google.com

Acked-by: David Hildenbrand (Red Hat) david@kernel.org