[PATCH v2 4/5] hugetlb: convert PageHugeTemporary() to HPageTemporary flag

Mike Kravetz
2021-01-20T01:40:46Z

Use new hugetlb specific HPageTemporary flag to replace the
PageHugeTemporary() interfaces.

Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
---
include/linux/hugetlb.h | 6 ++++++
mm/hugetlb.c | 36 +++++++-----------------------------
2 files changed, 13 insertions(+), 29 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 1e17529c8b81..ec329b9cc0fc 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -483,10 +483,15 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
* HPG_migratable - Set after a newly allocated page is added to the page
* cache and/or page tables. Indicates the page is a candidate for
* migration.
+ * HPG_temporary - - Set on a page that is temporarily allocated from the buddy
+ * allocator. Typically used for migration target pages when no pages
+ * are available in the pool. The hugetlb free page path will
+ * immediately free pages with this flag set to the buddy allocator.
*/
enum hugetlb_page_flags {
HPG_restore_reserve = 0,
HPG_migratable,
+ HPG_temporary,
__NR_HPAGEFLAGS,
};

@@ -534,6 +539,7 @@ static inline void ClearHPage##uname(struct page *page) \
*/
HPAGEFLAG(RestoreReserve, restore_reserve)
HPAGEFLAG(Migratable, migratable)
+HPAGEFLAG(Temporary, temporary)

#ifdef CONFIG_HUGETLB_PAGE

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6e32751489e8..0d2bfc2b6adc 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1353,28 +1353,6 @@ struct hstate *size_to_hstate(unsigned long size)
return NULL;
}

-/*
- * Internal hugetlb specific page flag. Do not use outside of the hugetlb
- * code
- */
-static inline bool PageHugeTemporary(struct page *page)
-{
- if (!PageHuge(page))
- return false;
-
- return (unsigned long)page[2].mapping == -1U;
-}
-
-static inline void SetPageHugeTemporary(struct page *page)
-{
- page[2].mapping = (void *)-1U;
-}
-
-static inline void ClearPageHugeTemporary(struct page *page)
-{
- page[2].mapping = NULL;
-}
-
static void __free_huge_page(struct page *page)
{
/*
@@ -1422,9 +1400,9 @@ static void __free_huge_page(struct page *page)
if (restore_reserve)
h->resv_huge_pages++;

- if (PageHugeTemporary(page)) {
+ if (HPageTemporary(page)) {
list_del(&page->lru);
- ClearPageHugeTemporary(page);
+ ClearHPageTemporary(page);
update_and_free_page(h, page);
} else if (h->surplus_huge_pages_node[nid]) {
/* remove the page from active list */
@@ -1863,7 +1841,7 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
* codeflow
*/
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
- SetPageHugeTemporary(page);
+ SetHPageTemporary(page);
spin_unlock(&hugetlb_lock);
put_page(page);
return NULL;
@@ -1894,7 +1872,7 @@ static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
* We do not account these pages as surplus because they are only
* temporary and will be released properly on the last reference
*/
- SetPageHugeTemporary(page);
+ SetHPageTemporary(page);

return page;
}
@@ -5607,12 +5585,12 @@ void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason)
* here as well otherwise the global surplus count will not match
* the per-node's.
*/
- if (PageHugeTemporary(newpage)) {
+ if (HPageTemporary(newpage)) {
int old_nid = page_to_nid(oldpage);
int new_nid = page_to_nid(newpage);

- SetPageHugeTemporary(oldpage);
- ClearPageHugeTemporary(newpage);
+ SetHPageTemporary(oldpage);
+ ClearHPageTemporary(newpage);

spin_lock(&hugetlb_lock);
if (h->surplus_huge_pages_node[old_nid]) {
--
2.29.2