[PATCH v2 3/3] mm: rmap: support batched unmapping for file large folios

[Barry Song]

On Thu, Dec 11, 2025 at 4:17 PM Baolin Wang
<baolin.wang at linux.alibaba.com> wrote:
>
> Similar to folio_referenced_one(), we can apply batched unmapping for file
> large folios to optimize the performance of file folios reclamation.
>
> Performance testing:
> Allocate 10G clean file-backed folios by mmap() in a memory cgroup, and try to
> reclaim 8G file-backed folios via the memory.reclaim interface. I can observe
> 75% performance improvement on my Arm64 32-core server.
>
> W/o patch:
> real    0m1.018s
> user    0m0.000s
> sys     0m1.018s
>
> W/ patch:
> real    0m0.249s
> user    0m0.000s
> sys     0m0.249s
>
> Signed-off-by: Baolin Wang <baolin.wang at linux.alibaba.com>

It appears quite straightforward to introduce file folios support based on the
current lazyfree implementation.

Acked-by: Barry Song <baohua at kernel.org>