Re: [PATCH 2/6] mm: mlocking in try_to_unmap_one

[KOSAKI Motohiro]

> @@ -787,6 +787,8 @@ static int try_to_unmap_one(struct page
>  			ret = SWAP_MLOCK;
>  			goto out_unmap;
>  		}
> +		if (MLOCK_PAGES && TTU_ACTION(flags) == TTU_MUNLOCK)
> +			goto out_unmap;
>  	}
>  	if (!(flags & TTU_IGNORE_ACCESS)) {
>  		if (ptep_clear_flush_young_notify(vma, address, pte)) {
> @@ -852,12 +854,22 @@ static int try_to_unmap_one(struct page
>  	} else
>  		dec_mm_counter(mm, file_rss);
>  
> -
>  	page_remove_rmap(page);
>  	page_cache_release(page);
>  
>  out_unmap:
>  	pte_unmap_unlock(pte, ptl);
> +
> +	if (MLOCK_PAGES && ret == SWAP_MLOCK) {
> +		ret = SWAP_AGAIN;
> +		if (down_read_trylock(&vma->vm_mm->mmap_sem)) {
> +			if (vma->vm_flags & VM_LOCKED) {
> +				mlock_vma_page(page);
> +				ret = SWAP_MLOCK;
> +			}
> +			up_read(&vma->vm_mm->mmap_sem);
> +		}
> +	}
>  out:

Very small nit. How about this?


------------------------------------------------------------