hugetlb: convert PageHugeTemporary() to HPageTemporary flag

Use new hugetlb specific HPageTemporary flag to replace the
PageHugeTemporary() interfaces.  PageHugeTemporary does contain a
PageHuge() check.  However, this interface is only used within hugetlb
code where we know we are dealing with a hugetlb page.  Therefore, the
check can be eliminated.

Link: https://lkml.kernel.org/r/20210122195231.324857-5-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 77f2a032fe3246f5d3821b183add393001f08cae..e97498a21010acbcd4e96033eafb551db3681290 100644 (file)
--- 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,
 };
 
@@ -530,6 +535,7 @@ 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 727c09713627ca328802f508180e5e03a00aff66..4d7d4535a313968009cc93b3e079aef9b3cf1627 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1364,28 +1364,6 @@ 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)
 {
        /*
@@ -1433,9 +1411,9 @@ 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 */
@@ -1869,7 +1847,7 @@ 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;
@@ -1900,7 +1878,7 @@ 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;
 }
@@ -5625,12 +5603,12 @@ 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]) {