diff mbox series

[v2,1/6] mm: rmap: fix cache flush on THP pages

Message ID 20220202143307.96282-2-songmuchun@bytedance.com (mailing list archive)
State New
Headers show
Series Fix some bugs related to ramp and dax | expand

Commit Message

Muchun Song Feb. 2, 2022, 2:33 p.m. UTC
The flush_cache_page() only remove a PAGE_SIZE sized range from the cache.
However, it does not cover the full pages in a THP except a head page.
Replace it with flush_cache_range() to fix this issue. At least, no
problems were found due to this. Maybe because the architectures that
have virtual indexed caches is less.

Fixes: f27176cfc363 ("mm: convert page_mkclean_one() to use page_vma_mapped_walk()")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
---
 mm/rmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Jan Kara Feb. 3, 2022, 10:16 a.m. UTC | #1
On Wed 02-02-22 22:33:02, Muchun Song wrote:
> The flush_cache_page() only remove a PAGE_SIZE sized range from the cache.
> However, it does not cover the full pages in a THP except a head page.
> Replace it with flush_cache_range() to fix this issue. At least, no
> problems were found due to this. Maybe because the architectures that
> have virtual indexed caches is less.
> 
> Fixes: f27176cfc363 ("mm: convert page_mkclean_one() to use page_vma_mapped_walk()")
> Signed-off-by: Muchun Song <songmuchun@bytedance.com>
> Reviewed-by: Yang Shi <shy828301@gmail.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  mm/rmap.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/rmap.c b/mm/rmap.c
> index b0fd9dc19eba..0ba12dc9fae3 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -974,7 +974,8 @@ 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);
>  			entry = pmdp_invalidate(vma, address, pmd);
>  			entry = pmd_wrprotect(entry);
>  			entry = pmd_mkclean(entry);
> -- 
> 2.11.0
>
diff mbox series

Patch

diff --git a/mm/rmap.c b/mm/rmap.c
index b0fd9dc19eba..0ba12dc9fae3 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -974,7 +974,8 @@  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);
 			entry = pmdp_invalidate(vma, address, pmd);
 			entry = pmd_wrprotect(entry);
 			entry = pmd_mkclean(entry);