diff mbox series

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

Message ID 20210120013049.311822-5-mike.kravetz@oracle.com (mailing list archive)
State New
Headers show
Series create hugetlb flags to consolidate state | expand

Commit Message

Mike Kravetz Jan. 20, 2021, 1:30 a.m. UTC
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(-)

Comments

Oscar Salvador Jan. 20, 2021, 10:09 a.m. UTC | #1
On Tue, Jan 19, 2021 at 05:30:48PM -0800, Mike Kravetz wrote:
> Use new hugetlb specific HPageTemporary flag to replace the
> PageHugeTemporary() interfaces.
> 
> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>

I would have added a brief comment explaining why it is ok to drop
the PageHuge() check in PageHugeTemporary.
AFAICS, the paths checking it already know they are handling with a 
hugetlb page, but still it is better to mention it in the changelog
in case someone wonders.

Other than that looks good to me:

Reviewed-by: Oscar Salvador <osalvador@suse.de>

> ---
>  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
>
Mike Kravetz Jan. 20, 2021, 6:14 p.m. UTC | #2
On 1/20/21 2:09 AM, Oscar Salvador wrote:
> On Tue, Jan 19, 2021 at 05:30:48PM -0800, Mike Kravetz wrote:
>> Use new hugetlb specific HPageTemporary flag to replace the
>> PageHugeTemporary() interfaces.
>>
>> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
> 
> I would have added a brief comment explaining why it is ok to drop
> the PageHuge() check in PageHugeTemporary.
> AFAICS, the paths checking it already know they are handling with a 
> hugetlb page, but still it is better to mention it in the changelog
> in case someone wonders.

Thanks.

Since I have to do another version, I will add this.
diff mbox series

Patch

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]) {