[RFC PATCH 09/39] mm: hugetlb: Expose hugetlb_subpool_{get,put}_pages()

From: Ackerley Tng
Date: Tue Sep 10 2024 - 19:48:24 EST


This will allow hugetlb subpools to be used by guest_memfd.

Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
include/linux/hugetlb.h | 3 +++
mm/hugetlb.c | 6 ++----
2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index e4a05a421623..907cfbbd9e24 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -119,6 +119,9 @@ struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
long min_hpages);
void hugepage_put_subpool(struct hugepage_subpool *spool);

+long hugepage_subpool_get_pages(struct hugepage_subpool *spool, long delta);
+long hugepage_subpool_put_pages(struct hugepage_subpool *spool, long delta);
+
void hugetlb_dup_vma_private(struct vm_area_struct *vma);
void clear_vma_resv_huge_pages(struct vm_area_struct *vma);
int move_hugetlb_page_tables(struct vm_area_struct *vma,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7e73ebcc0f26..808915108126 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -170,8 +170,7 @@ void hugepage_put_subpool(struct hugepage_subpool *spool)
* only be different than the passed value (delta) in the case where
* a subpool minimum size must be maintained.
*/
-static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
- long delta)
+long hugepage_subpool_get_pages(struct hugepage_subpool *spool, long delta)
{
long ret = delta;

@@ -215,8 +214,7 @@ static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
* The return value may only be different than the passed value (delta)
* in the case where a subpool minimum size must be maintained.
*/
-static long hugepage_subpool_put_pages(struct hugepage_subpool *spool,
- long delta)
+long hugepage_subpool_put_pages(struct hugepage_subpool *spool, long delta)
{
long ret = delta;
unsigned long flags;
--
2.46.0.598.g6f2099f65c-goog