[v1] mm: No need to check pcp page when free it to buddy

[PATCH] mm: No need to check pcp page when free it to buddy

Posted by zhaoyang.huang 3 years, 6 months ago

From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>

The pages on pcp list have been checked the validity from each entrance. It is
no need to check it again when free them back to buddy.

Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
---
 mm/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e008a3d..131536e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1445,7 +1445,7 @@ static bool free_pcp_prepare(struct page *page, unsigned int order)
 
 static bool bulkfree_pcp_prepare(struct page *page)
 {
-	return check_free_page(page);
+	return false;
 }
 #endif /* CONFIG_DEBUG_VM */
 
-- 
1.9.1

Re: [PATCH] mm: No need to check pcp page when free it to buddy

Posted by Andrew Morton 3 years, 6 months ago

On Wed, 14 Sep 2022 18:53:40 +0800 "zhaoyang.huang" <zhaoyang.huang@unisoc.com> wrote:

> From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> 
> The pages on pcp list have been checked the validity from each entrance. It is
> no need to check it again when free them back to buddy.
> 

I'm not sure what "from each entrance" means.  Please identify the
codesite where this other check is occurring?

> ---
>  mm/page_alloc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3d..131536e 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1445,7 +1445,7 @@ static bool free_pcp_prepare(struct page *page, unsigned int order)
>  
>  static bool bulkfree_pcp_prepare(struct page *page)
>  {
> -	return check_free_page(page);
> +	return false;
>  }
>  #endif /* CONFIG_DEBUG_VM */