Re: [PATCH v10 05/18] mm: mark vmas detached upon exit

["Liam R. Howlett" <Liam.Howlett@oracle.com>]

* Suren Baghdasaryan <surenb@google.com> [250213 17:47]:
> When exit_mmap() removes vmas belonging to an exiting task, it does not
> mark them as detached since they can't be reached by other tasks and they
> will be freed shortly. Once we introduce vma reuse, all vmas will have to
> be in detached state before they are freed to ensure vma when reused is
> in a consistent state. Add missing vma_mark_detached() before freeing the
> vma.
> 
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

> ---
> Changes since v9 [1]:
> - Add Reviewed-by, per Lorenzo Stoakes
> 
> [1] https://lore.kernel.org/all/20250111042604.3230628-6-surenb@google.com/
> 
>  mm/vma.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/vma.c b/mm/vma.c
> index f72b73f57451..a16a83d0253f 100644
> --- a/mm/vma.c
> +++ b/mm/vma.c
> @@ -427,10 +427,12 @@ void remove_vma(struct vm_area_struct *vma, bool unreachable)
>  	if (vma->vm_file)
>  		fput(vma->vm_file);
>  	mpol_put(vma_policy(vma));
> -	if (unreachable)
> +	if (unreachable) {
> +		vma_mark_detached(vma);
>  		__vm_area_free(vma);
> -	else
> +	} else {
>  		vm_area_free(vma);
> +	}
>  }
>  
>  /*
> -- 
> 2.48.1.601.g30ceb7b040-goog
>