diff options
Diffstat (limited to 'include/linux/huge_mm.h')
| -rw-r--r-- | include/linux/huge_mm.h | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index db51201..b826239 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -157,46 +157,6 @@ static inline int hpage_nr_pages(struct page *page) return HPAGE_PMD_NR; return 1; } -/* - * compound_trans_head() should be used instead of compound_head(), - * whenever the "page" passed as parameter could be the tail of a - * transparent hugepage that could be undergoing a - * __split_huge_page_refcount(). The page structure layout often - * changes across releases and it makes extensive use of unions. So if - * the page structure layout will change in a way that - * page->first_page gets clobbered by __split_huge_page_refcount, the - * implementation making use of smp_rmb() will be required. - * - * Currently we define compound_trans_head as compound_head, because - * page->private is in the same union with page->first_page, and - * page->private isn't clobbered. However this also means we're - * currently leaving dirt into the page->private field of anonymous - * pages resulting from a THP split, instead of setting page->private - * to zero like for every other page that has PG_private not set. But - * anonymous pages don't use page->private so this is not a problem. - */ -#if 0 -/* This will be needed if page->private will be clobbered in split_huge_page */ -static inline struct page *compound_trans_head(struct page *page) -{ - if (PageTail(page)) { - struct page *head; - head = page->first_page; - smp_rmb(); - /* - * head may be a dangling pointer. - * __split_huge_page_refcount clears PageTail before - * overwriting first_page, so if PageTail is still - * there it means the head pointer isn't dangling. - */ - if (PageTail(page)) - return head; - } - return page; -} -#else -#define compound_trans_head(page) compound_head(page) -#endif extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr, pmd_t pmd, pmd_t *pmdp); @@ -226,7 +186,6 @@ static inline int split_huge_page(struct page *page) do { } while (0) #define split_huge_page_pmd_mm(__mm, __address, __pmd) \ do { } while (0) -#define compound_trans_head(page) compound_head(page) static inline int hugepage_madvise(struct vm_area_struct *vma, unsigned long *vm_flags, int advice) { |
