mm/hugetlb_vmemmap.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Free some vmemmap pages of HugeTLB
   4  *
   5  * Copyright (c) 2020, Bytedance. All rights reserved.
   6  *
   7  *     Author: Muchun Song <songmuchun@bytedance.com>
   8  */
   9 #ifndef _LINUX_HUGETLB_VMEMMAP_H
  10 #define _LINUX_HUGETLB_VMEMMAP_H
  11 #include <linux/hugetlb.h>
  12
  13 #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
  14 int alloc_huge_page_vmemmap(struct hstate *h, struct page *head);
  15 void free_huge_page_vmemmap(struct hstate *h, struct page *head);
  16 void hugetlb_vmemmap_init(struct hstate *h);
  17
  18 /*
  19  * How many vmemmap pages associated with a HugeTLB page that can be freed
  20  * to the buddy allocator.
  21  */
  22 static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
  23 {
  24         return h->nr_free_vmemmap_pages;
  25 }
  26 #else
  27 static inline int alloc_huge_page_vmemmap(struct hstate *h, struct page *head)
  28 {
  29         return 0;
  30 }
  31
  32 static inline void free_huge_page_vmemmap(struct hstate *h, struct page *head)
  33 {
  34 }
  35
  36 static inline void hugetlb_vmemmap_init(struct hstate *h)
  37 {
  38 }
  39
  40 static inline unsigned int free_vmemmap_pages_per_hpage(struct hstate *h)
  41 {
  42         return 0;
  43 }
  44 #endif /* CONFIG_HUGETLB_PAGE_FREE_VMEMMAP */
  45 #endif /* _LINUX_HUGETLB_VMEMMAP_H */