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[PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()

Zi Yan posted 3 patches 1 month, 2 weeks ago
There is a newer version of this series
[PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by Zi Yan 1 month, 2 weeks ago 
When caller does not supply a list to split_huge_page_to_list_to_order(),
use split_huge_page_to_order() instead.

Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
 include/linux/huge_mm.h | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 7698b3542c4f..34f8d8453bf3 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -381,6 +381,10 @@ static inline int split_huge_page_to_list_to_order(struct page *page, struct lis
 {
 	return __split_huge_page_to_list_to_order(page, list, new_order, false);
 }
+static inline int split_huge_page_to_order(struct page *page, unsigned int new_order)
+{
+	return split_huge_page_to_list_to_order(page, NULL, new_order);
+}
 
 /*
  * try_folio_split_to_order - try to split a @folio at @page to @new_order using
@@ -400,8 +404,7 @@ static inline int try_folio_split_to_order(struct folio *folio,
 		struct page *page, unsigned int new_order)
 {
 	if (!non_uniform_split_supported(folio, new_order, /* warns= */ false))
-		return split_huge_page_to_list_to_order(&folio->page, NULL,
-				new_order);
+		return split_huge_page_to_order(&folio->page, new_order);
 	return folio_split(folio, new_order, page, NULL);
 }
 static inline int split_huge_page(struct page *page)
@@ -590,6 +593,11 @@ split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
 	VM_WARN_ON_ONCE_PAGE(1, page);
 	return -EINVAL;
 }
+static inline int split_huge_page_to_order(struct page *page, unsigned int new_order)
+{
+	VM_WARN_ON_ONCE_PAGE(1, page);
+	return -EINVAL;
+}
 static inline int split_huge_page(struct page *page)
 {
 	VM_WARN_ON_ONCE_PAGE(1, page);
-- 
2.43.0
Re: [PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by David Hildenbrand 1 month, 1 week ago 
On 30.10.25 02:40, Zi Yan wrote:
> When caller does not supply a list to split_huge_page_to_list_to_order(),
> use split_huge_page_to_order() instead.
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> ---
>   include/linux/huge_mm.h | 12 ++++++++++--
>   1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 7698b3542c4f..34f8d8453bf3 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -381,6 +381,10 @@ static inline int split_huge_page_to_list_to_order(struct page *page, struct lis
>   {
>   	return __split_huge_page_to_list_to_order(page, list, new_order, false);
>   }
> +static inline int split_huge_page_to_order(struct page *page, unsigned int new_order)
> +{
> +	return split_huge_page_to_list_to_order(page, NULL, new_order);
> +}
>   

Scanning this once again, I guess in the future all these interfaces 
should rather be folio-based, and if we want to split at a specific page 
where we want the reference to be held later, pass in a page:

int folio_split_to_order(struct folio *folio, struct page *page,
			 unsigned int new_order);

With the hope that we could end up with all folio split functions to
look similar in that regard ... and remove all the "huge_page" terminology.

Of course, that can be done as cleanups on top, because there seems to 
be quite some inconsistency already.


-- 
Cheers

David / dhildenb
Re: [PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by Wei Yang 1 month, 2 weeks ago 
On Wed, Oct 29, 2025 at 09:40:18PM -0400, Zi Yan wrote:
>When caller does not supply a list to split_huge_page_to_list_to_order(),
>use split_huge_page_to_order() instead.
>
>Signed-off-by: Zi Yan <ziy@nvidia.com>
>Acked-by: David Hildenbrand <david@redhat.com>
>Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Reviewed-by: Wei Yang <richard.weiyang@gmail.com>

-- 
Wei Yang
Help you, Help me
Re: [PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by Miaohe Lin 1 month, 2 weeks ago 
On 2025/10/30 9:40, Zi Yan wrote:
> When caller does not supply a list to split_huge_page_to_list_to_order(),
> use split_huge_page_to_order() instead.
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>

Thanks.
.
Re: [PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by Barry Song 1 month, 2 weeks ago 
On Thu, Oct 30, 2025 at 9:40 AM Zi Yan <ziy@nvidia.com> wrote:
>
> When caller does not supply a list to split_huge_page_to_list_to_order(),
> use split_huge_page_to_order() instead.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>

LGTM,

Reviewed-by: Barry Song <baohua@kernel.org>

> ---
>  include/linux/huge_mm.h | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
>
Re: [PATCH v4 1/3] mm/huge_memory: add split_huge_page_to_order()
Posted by Lance Yang 1 month, 2 weeks ago 

On 2025/10/30 09:40, Zi Yan wrote:
> When caller does not supply a list to split_huge_page_to_list_to_order(),
> use split_huge_page_to_order() instead.
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> ---

Reviewed-by: Lance Yang <lance.yang@linux.dev>

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