Re: [PATCH 1/5] mm: rmap: fix cache flush on THP pages

[Christoph Hellwig]

On Fri, Jan 21, 2022 at 03:55:11PM +0800, Muchun Song wrote:
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/rmap.c b/mm/rmap.c
> index b0fd9dc19eba..65670cb805d6 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -974,7 +974,7 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
>  			if (!pmd_dirty(*pmd) && !pmd_write(*pmd))
>  				continue;
>  
> -			flush_cache_page(vma, address, page_to_pfn(page));
> +			flush_cache_range(vma, address, address + HPAGE_PMD_SIZE);

Do we need a flush_cache_folio here given that we must be dealing with
what effectively is a folio here?

Also please avoid the overly long line.