diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e2d1587be26..6b072bdccf8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1052,6 +1052,51 @@ int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, return ret; } +int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma, + unsigned long old_addr, + unsigned long new_addr, unsigned long old_end, + pmd_t *old_pmd, pmd_t *new_pmd) +{ + int ret = 0; + pmd_t pmd; + + struct mm_struct *mm = vma->vm_mm; + + if ((old_addr & ~HPAGE_PMD_MASK) || + (new_addr & ~HPAGE_PMD_MASK) || + old_end - old_addr < HPAGE_PMD_SIZE || + (new_vma->vm_flags & VM_NOHUGEPAGE)) + goto out; + + /* + * The destination pmd shouldn't be established, free_pgtables() + * should have release it. + */ + if (WARN_ON(!pmd_none(*new_pmd))) { + VM_BUG_ON(pmd_trans_huge(*new_pmd)); + goto out; + } + + spin_lock(&mm->page_table_lock); + if (likely(pmd_trans_huge(*old_pmd))) { + if (pmd_trans_splitting(*old_pmd)) { + spin_unlock(&mm->page_table_lock); + wait_split_huge_page(vma->anon_vma, old_pmd); + ret = -1; + } else { + pmd = pmdp_get_and_clear(mm, old_addr, old_pmd); + VM_BUG_ON(!pmd_none(*new_pmd)); + set_pmd_at(mm, new_addr, new_pmd, pmd); + spin_unlock(&mm->page_table_lock); + ret = 1; + } + } else { + spin_unlock(&mm->page_table_lock); + } +out: + return ret; +} + int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, pgprot_t newprot) { |