Re: [PATCH 01/12] mm/khugepaged: drop redundant mm_struct pin in madvise_collapse()

[Zi Yan]

On Fri Sep 4, 2026 at 11:10 AM EDT, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx>
>
> madvise_collapse() holds an mmgrab() reference across its work. It is
> redundant. Every caller already holds mm_users:
>
>  - madvise(2) works on current->mm, which lives as long as the task is in
>    the syscall;
>  - process_madvise(2) reaches a remote mm through mm_access(), which takes
>    an mm_users reference and holds it until the syscall returns;
>  - io_uring passes current->mm;
>  - DAMON takes one with get_task_mm() and drops it after the call.
>
> Drop the mmgrab()/mmdrop() pair.
>
> Assisted-by: Claude-Code:claude-opus-5
> Signed-off-by: Kiryl Shutsemau (Meta) <kas@xxxxxxxxxx>
> ---
>  mm/khugepaged.c | 2 --
>  1 file changed, 2 deletions(-)
>

Makes sense.

Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>


-- 
Best Regards,
Yan, Zi