[v3,5/5] hugetlb: convert PageHugeFreed to HPageFreed flag

Commit Message

Mike Kravetz Jan. 22, 2021, 7:52 p.m. UTC

Use new hugetlb specific HPageFreed flag to replace the
PageHugeFreed interfaces.

Signed-off-by: Mike Kravetz <[e-mail]>
Reviewed-by: Oscar Salvador <[e-mail]>
Reviewed-by: Muchun Song <[e-mail]>
---
 include/linux/hugetlb.h |  3 +++
 mm/hugetlb.c            | 23 ++++-------------------
 2 files changed, 7 insertions(+), 19 deletions(-)

Comments

Michal Hocko Jan. 27, 2021, 10:41 a.m. UTC | #1

On Fri 22-01-21 11:52:31, Mike Kravetz wrote:
> Use new hugetlb specific HPageFreed flag to replace the
> PageHugeFreed interfaces.
> 
> Signed-off-by: Mike Kravetz <[e-mail]>
> Reviewed-by: Oscar Salvador <[e-mail]>
> Reviewed-by: Muchun Song <[e-mail]>

Acked-by: Michal Hocko <[e-mail]>

Again I would love to see locking that is required to gain a stable
value.

Thanks!

Mike Kravetz Jan. 27, 2021, 11:37 p.m. UTC | #2

On 1/27/21 2:41 AM, Michal Hocko wrote:
> On Fri 22-01-21 11:52:31, Mike Kravetz wrote:
>> Use new hugetlb specific HPageFreed flag to replace the
>> PageHugeFreed interfaces.
>>
>> Signed-off-by: Mike Kravetz <[e-mail]>
>> Reviewed-by: Oscar Salvador <[e-mail]>
>> Reviewed-by: Muchun Song <[e-mail]>
> 
> Acked-by: Michal Hocko <[e-mail]>
> 
> Again I would love to see locking that is required to gain a stable
> value.

Will do

Patch

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3c86c3a0e144..f09085c0afea 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -487,11 +487,13 @@  unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
  *	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.
+ * HPG_freed - Set when page is on the free lists.
  */
 enum hugetlb_page_flags {
 	HPG_restore_reserve = 0,
 	HPG_migratable,
 	HPG_temporary,
+	HPG_freed,
 	__NR_HPAGEFLAGS,
 };
 
@@ -536,6 +538,7 @@  static inline void ClearHPage##uname(struct page *page)		\
 HPAGEFLAG(RestoreReserve, restore_reserve)
 HPAGEFLAG(Migratable, migratable)
 HPAGEFLAG(Temporary, temporary)
+HPAGEFLAG(Freed, freed)
 
 #ifdef CONFIG_HUGETLB_PAGE
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 70ffa1027988..c1f283cee0a9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -79,21 +79,6 @@  DEFINE_SPINLOCK(hugetlb_lock);
 static int num_fault_mutexes;
 struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp;
 
-static inline bool PageHugeFreed(struct page *head)
-{
-	return page_private(head + 4) == -1UL;
-}
-
-static inline void SetPageHugeFreed(struct page *head)
-{
-	set_page_private(head + 4, -1UL);
-}
-
-static inline void ClearPageHugeFreed(struct page *head)
-{
-	set_page_private(head + 4, 0);
-}
-
 /* Forward declaration */
 static int hugetlb_acct_memory(struct hstate *h, long delta);
 
@@ -1043,7 +1028,7 @@  static void enqueue_huge_page(struct hstate *h, struct page *page)
 	list_move(&page->lru, &h->hugepage_freelists[nid]);
 	h->free_huge_pages++;
 	h->free_huge_pages_node[nid]++;
-	SetPageHugeFreed(page);
+	SetHPageFreed(page);
 }
 
 static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
@@ -1060,7 +1045,7 @@  static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
 
 		list_move(&page->lru, &h->hugepage_activelist);
 		set_page_refcounted(page);
-		ClearPageHugeFreed(page);
+		ClearHPageFreed(page);
 		h->free_huge_pages--;
 		h->free_huge_pages_node[nid]--;
 		return page;
@@ -1474,7 +1459,7 @@  static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 	spin_lock(&hugetlb_lock);
 	h->nr_huge_pages++;
 	h->nr_huge_pages_node[nid]++;
-	ClearPageHugeFreed(page);
+	ClearHPageFreed(page);
 	spin_unlock(&hugetlb_lock);
 }
 
@@ -1747,7 +1732,7 @@  int dissolve_free_huge_page(struct page *page)
 		 * We should make sure that the page is already on the free list
 		 * when it is dissolved.
 		 */
-		if (unlikely(!PageHugeFreed(head))) {
+		if (unlikely(!HPageFreed(head))) {
 			spin_unlock(&hugetlb_lock);
 			cond_resched();